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Class Outline
Objectives
What Is a Robot?
The History of Robotics
The Industrial Applications of Robots
Basic Robot Components
The Parts of a Robot’s Body
Arm-Shaped Robots
Robot Coordinate Systems
Robotic Arm Configuration
Mobile Robots
Robots and Artificial Intelligence
Robot Teaching Methods
Robot Safety
Trends in Industrial Robotics
Careers in Robotics
The Pros and Cons of Robots
Summary
Lesson: 1/17
Objectives
Lesson: 2/17
What Is a Robot?
Lesson: 3/17
The History of Robotics
Lesson: 4/17
The Industrial Applications of Robots
Lesson: 5/17
Basic Robot Components
Lesson: 6/17
The Parts of a Robot’s Body
Lesson: 7/17
Arm-Shaped Robots
Lesson: 8/17
Robot Coordinate Systems
Lesson: 9/17
Robotic Arm Configuration
Lesson: 10/17
Mobile Robots
Lesson: 11/17
Robots and Artificial Intelligence
Lesson: 12/17
Robot Teaching Methods
Lesson: 13/17
Robot Safety
Lesson: 14/17
Trends in Industrial Robotics
Lesson: 15/17
Careers in Robotics
Lesson: 16/17
The Pros and Cons of Robots
Lesson: 17/17
Summary
Class Vocabulary
Intro to Robotics 110
lDefine a robot.
lDescribe the history of industrial robotics.
lDescribe the industrial applications of robots.
lDescribe the basic components of a robot.
lDescribe the different parts of a robot’s body.
lDescribe robotic arms.
lDescribe the coordinate systems used to program
a robot’s movement.
lDistinguish between different robotic arm
configurations.
lDescribe mobile robots.
lDescribe artificial intelligence for robots.
lDistinguish between different robot teaching
methods.
lDescribe safety precautions for working with
robots.
lDescribe present and future trends in industrial
robotics.
lDescribe careers in robotics.
lList the advantages and disadvantages of using
robots.
Figure 1. Robots can have different coordinates depending on the point of origin.
Figure 2. In lead-through programming, the trainer uses a remote teach pendant
to program the robot.
People have been fascinated by the idea of automated machines for centuries.
Devices propelled by water and steam were created as early as 350 B.C.E.
Throughout history scientists and inventors became increasingly interested in
creating machines that could duplicate human anatomy and movement. This
eventually gave rise to the modern industrial robot.
An industrial robot is a programmable mechanical device used in place of a person
to perform dangerous or repetitive tasks with a high degree of accuracy. Not all
programmable machines are robots, however. The laser welding machine in Figure 1
is a robot, but a programmable VCR is not. A robot must be able to move on its
own, sense information about its environment, and use that information to
accomplish a programmed task. Robots can change their behavior in response to
their environment while automated machines simply follow instructions.
Robots can be large or small and they come in many shapes. They are capable of
lifting very heavy objects and performing repetitive tasks for long periods of time
without stopping. Figure 2 shows a machine tending robot. In this class you will
learn the classifications, characteristics, and functions of industrial robots. You will
also learn basic safety precautions for working with robots.
Figure 1. This arc welding robot moves on its own and
uses a vision sensor to accomplish its task. [Courtesy
of Kawasaki Robotics (USA), Inc.]
Figure 2. This machine tending robot can work for
many hours without getting bored or tired. [Courtesy
of Kawasaki Robotics (USA), Inc.]
Industrial robots were first used in the 1960s. U.S. companies were looking for cheap
labor, and robotics was a potential solution. However, early robots were bulky, slow, and
inefficient. The amount of human effort required to keep the robots running cancelled out
any cost advantage that the robots provided. In the end, manufacturers realized that
robots could never fully replace people. Instead, robots simply became another part of
factory technology. The welding robots in Figure 1 are very good at their job, but they
do not have the flexibility and intelligence of a human worker.
The use of industrial robots increased significantly after stepper motors became smaller
and stronger and AC servomotors became more affordable. These developments, along
with the use of transistors and integrated circuits, improved the productivity of
robots.
Today’s robots are extremely smart and versatile. In the military, planes known as
unmanned aerial vehicles (UAVs) can fly without an onboard pilot. Robots are also
used for exploration. NASA makes extensive use of small robotic vehicles, like the rover
in Figure 2, to explore other planets.
Figure 1. Robots are an important part of factory
technology, but they will never fully replace
people.
Figure 2. NASA uses mobile robots like this Mars
rover to explore other planets.
In industry, robots perform a wide variety of tasks. They are often used to handle
materials that are extremely hot or heavy. For example, robots are used to remove
a waste product called dross from molten metal baths. A skimmer full of dross can
weigh up to 33 lbs (72.2 kg). In addition, metal baths can reach temperatures that
exceed 800°F (426°C). For a human, skimming dross would be a hot, exhausting,
and potentially dangerous job. But a robot can perform this work quickly and easily
without being harmed.
One of the most common industrial applications for robots is welding, shown in
Figure 1. Robots are ideal for welding because of their high speed, the uniform
quality of their work, and their ability to repeat tasks without wearing out. The
automotive industry is one of the largest users of robotic welders.
Spray painting, shown in Figure 2, is another common use for robots. The highly
repetitive motions required in spray painting are well-suited to robots. Robots can
paint quickly and efficiently with nearly perfect quality. Because of their speed and
efficiency, robots also use less paint.
The newspaper industry makes extensive use of robots for a type of materials
handling called palletizing. The robots load and unload stacks of newspapers onto
movable platforms called pallets. Other industrial uses for robots include
packaging, part transfer, pick and place, machine loading, material removal,
and assembly. An assembly robot is shown in Figure 3.
Robots are also an ideal resource for working with integrated circuits in a clean
room. ICs are extremely sensitive to dust and dirt and other types of debris.
Because robots have no skin, hair, or breath, they do not contaminate the clean
room environment.
Figure 1. Welding is a common industrial robot
application. [Courtesy of Kawasaki Robotics (USA),
Inc.]
Figure 2. This spray painting robot works quickly and
efficiently with nearly perfect quality. [Courtesy of
Kawasaki Robotics (USA), Inc.]
Figure 3. An assembly robot. [Courtesy of Kawasaki
Robotics (USA), Inc.]
Figure 1 illustrates the basic components that make up an industrial robot. These
components are the power supply, controller, teach pendant, axis control module,
input/output modules, and mechanical body. The main power supply to the robot is
AC run through a transformer. This main power supply provides voltage and current
to the robot's motor. The motor can be servo or non-servo. Servomotors, like the
one in Figure 2, are used for applications such as pick and place that require the robot
to move to a precise location.
In addition to the main power supply, there are separate power supplies to the robot
that can be located in a cabinet, shown in Figure 3, or in a power supply unit (PSU).
The PSU provides DC voltage to the robot's outputs and controller. Robots can be also
be powered by batteries, solar panels, springs, hydraulics, and pneumatics. However,
most industrial robots use a plug-in power supply.
In order to run its program and interface with inputs and outputs, a robot must have a
controller. The controller can be located in a cabinet that is external to the robot, or it
can be a microcontroller (MCU) inside the robot. A hand-held remote control called a
teach pendant is connected to the controller and is used to program the robot. Teach
pendants are connected to the controller by a cable.
The axis control module, which is also connected to the controller, allows the robot
to move through the coordinates specified by its program. The axis control module
also controls the speed at which the robot's body moves. Figure 1. An industrial robot is composed of a
power supply, controller, axis control module, and
mechanical body.
Figure 2. Servomotors are used for robotic
applications that require precise positioning.
Figure 3. A cabinet holding the controller and teach
pendant. [Courtesy of Kawasaki Robotics (USA),
Inc.]
A robot’s body consists of different mechanical parts that are typically made from some
type of metal or alloy such as steel, cast iron, or aluminum. For a robotic arm, the body
parts can include a base, shoulder, elbow, arm, wrist, and even fingers. Figure 1 shows a
basic robotic arm. Links and joints within the robotic arm allow the robot to move in
different directions.
An end-of-arm tool (EOAT), also known as the end-effector, is attached to the end
joint of the arm. End-effectors can be shaped like hands, like the one in Figure 2, or they
can be highly specialized tools, like the grinder in Figure 3. Hand-shaped effectors are
called grippers. Grippers come in many shapes and sizes. Tools also come in a wide
variety and are designed for specific tasks such as welding or grinding.
Effectors are activated in response to signals that the robot sends and receives through
an input/output module. Input signals from sensors on or near the robot provide
information about its surroundings. Output signals are then sent to the robotic arm to
activate the work tool. Figure 1. A robotic arm typically includes a base,
shoulder, arm, and end-effector.
Figure 2. A gripper is an end-effector that is
shaped like a hand.
Figure 3. This robot is using an end-of-arm tool
that is specifically for grinding.
There are two major classes of robots: fixed robotic arms and mobile robotic vehicles.
The robotic arm in Figure 1 is also known as a manipulator. A manipulator resembles
a human arm with a shoulder, elbow, wrist, and fingers. The manipulator is generally
mounted on a platform or suspended from a track while the arm reaches to various
distances and locations.
The joints on a robotic arm can move in different directions along particular axes. An
axis is an imaginary line or circle along which a robotic component can move. The axes
of a robotic joint can allow movement side-to-side, up and down, in and out, or in a
circle. Collectively these axes represent the robot's degrees of freedom.
Robotic arms have two basic types of joints. Prismatic joints, also known as linear
joints, slide in a straight line across one axis. A revolute joint, on the other hand,
gives a robotic arm a wide range of movement. Revolute joints rotate almost
exclusively around one axis like a shaft in a bearing. To make a single joint rotate
around more than one axis requires a ball-and-socket type of bearing and drive. This is
hard to build, has accuracy and wear issues, and is difficult to drive. The robot in
Figure 2 has two prismatic joints and one revolute joint.
Figure 1. A robotic arm is generally mounted on a
platform from which it reaches to various distances
and locations.
Figure 2. Prismatic joints slide in a straight line
across one axis while revolute joints rotate around
an axis.
In order to tell a robot where to move, an operator must be familiar with the
Cartesian coordinate system. The Cartesian coordinate system defines the
location of a single point in three-dimensional space using three axes. The X-axis,
Y-axis, and Z-axis join together like the corner of a box. The point where all the
axes meet is the origin. The X and Y axes are horizontal, with one axis going in
and out, and one axis going side-to-side. The Z axis goes up and down.
An effective way to picture the three Cartesian axes is by using the right-hand
rule. Place your hand on a table or a bench. Turn your right palm up, and then
extend only the thumb and forefinger. This forms an "L," with the middle finger up
to the ceiling, as shown in Figure 1. The thumb is the X-axis, the forefinger is the
Y-axis, and the elevated center finger is the Z-axis.
The positions of a robot are referenced according to different coordinate systems.
The coordinate systems vary depending on the point of origin. World coordinates
use the robot’s mounting base as a point of origin, as shown in Figure 2. Tool
coordinates use the tool at the end of the robot’s arm as the point of origin. Tool
coordinates are used for teaching the robot where to move. With tool coordinates,
the X, Y, and Z axes are set from the tool’s point of view. Figure 1. Using the right-hand rule, the thumb is the
X-axis, the forefinger is the Y-axis, and the elevated
center finger is the Z-axis
Figure 2. A robot can have different sets of
coordinates.
Robotic arms come in a variety of styles. Articulated robots, like the one illustrated
in Figure 1, most closely resemble a human arm. The arm of an articulated robot has
revolute joints, and the number of joints can vary. Articulated robots are very good
at picking up small objects.
A Cartesian robot, shown in Figure 2, has prismatic joints only. The linear
movement of the joints gives the Cartesian robot a highly rigid structure that allows
it to lift heavy objects. Cartesian robots are also extremely precise because of the
accuracy and arrangements of the prismatic bearings. Cartesian robots can move
through X, Y, and Z axes. The length of each axis can be adjusted depending on the
application. Cartesian robots are used for assembly and injection molding
applications.
Cylindrical robots have a combination of revolute and prismatic joints that allow
them to work well in round workspaces. Spherical robots, on the other hand, have a
joint configuration that allows the robot to move in a desired direction and then
extend to reach an object. Figure 3 shows a spherical robot. Spherical robots are
used for welding and material handling. A typical spherical robot has 4 to 6 revolute
joints.
SCARA robots are a type of cylindrical robot. SCARA stands for Selective Compliance
Arm for Robotic Assembly. The SCARA robot illustrated in Figure 4 has four axes of
movement. It can move through X, Y, Z coordinates and a fourth Theta Z
coordinate. Theta Z is a rotating axis that corresponds to the angle around the z-
axis of the tool at the end of the SCARA robot. SCARA robots are often used for
inserting electronic components into circuit boards. SCARA robots generally have
three parallel revolute joints and two parallel prismatic joints that are both in the Z
direction.
Figure 1. An articulated robot has revolute joints
only.
Figure 2. A Cartesian robot has prismatic joints
only.
Figure 3. This spherical robot can turn around on its
base and reach for an object.
Figure 4. SCARA robots can move through X, Y, Z
coordinates and a fourth Theta Z coordinate
corresponding to the end-effector.
The robotic arm is the most common type of industrial robot. However, there is a second
type of industrial robot known as the automatic guided vehicle (AGV). Unlike a robotic
arm, an AGV can move freely about the workspace. Instead of having a driver for
navigation, the AGV uses light reflectors, colored tape, or wires that are embedded in the
floor to guide it through a predetermined route.
There are four types of AGVs:
lTow vehicles, also known as tuggers (Figure 1), pull trailers loaded with material.
Tow vehicles are capable of pulling extremely heavy loads, some weighing up to
60,000 lbs. (27,215 kg). Tow vehicles do not load the materials; they simply
transport them.
lUnit load carriers (Figure 2) have powered decks that lift and lower to transport
pallets loaded with material.
lCart vehicles (Figure 3) are small, relatively inexpensive AGVs that can load material
like a unit load carrier or pull it like a tow vehicle. However, cart vehicles are usually
limited to loads of no more than 2,000 lbs. (907 kg).
lFork vehicles (Figure 4) lift and lower materials. Their load capacity can range from
1,200 to 5,000 lbs. (544 to 2,267 kg). Forks are available in different styles other
than the standard dual fork.
AGVs are extremely flexible in the distance and direction that they can move. You can find
AGVs in automotive, printing, chemical, medical and pharmaceutical, food and beverage,
distribution, paper, manufacturing, and warehousing applications.
Figure 1. A tow vehicle is capable of pulling
extremely heavy loads.
Figure 2. A unit load carrier has powered decks
that lift and lower.
Figure 3. A cart vehicle cannot pull loads
greater than 2,000 lbs. (907 kg).
Figure 4. Fork vehicles primarily lift and lower
materials.
In order to be considered a robot, a machine must have some form of artificial
intelligence. Artificial intelligence is simply a computer software program that contains
behavior rules, as shown in Figure 1. These rules tell the robot how to act as it learns
how to perform its job. For example, a robot could be programmed to move toward a
light source when light is detected by its photosensors. Or it could be programmed to
move away from any objects that come into contact with the robot’s feelers. Figure 2
shows how a robot learns to adjust its path after colliding with an object.
Like human intelligence, an artificial intelligence program controls different levels of
behavior. The lowest, most primitive level of artificial intelligence simply allows the robot
to move its mechanical parts. The next level controls the robot’s reflexes so it can
respond to its environment and make decisions based on the information detected by
its sensors. The highest level of artificial intelligence is devoted to the robot’s memory
and problem-solving abilities.
Figure 1. Artificial intelligence is simply a computer
software program. [Courtesy of Kawasaki Robotics
(USA), Inc.]
Figure 2. After colliding with an object, this robot
learns to adjust its path. (Courtesy of Kawasaki
Robotics (USA), Inc.)
Like a human worker, a robot must be trained to do its job correctly. While it is
possible for some robots to simply learn on their own by trial and error, most robots
are taught by humans. The three main methods for teaching robots are lead-through
programming, walk-through programming, and off-line programming.
In lead-through programming, shown in Figure 1, the robot is placed in "teach
mode" while the trainer uses a remote teach pendant to manipulate the robot through
the different steps of the job. This is the most common programming method. The
robot is moved manually via the teach pendant, which controls the robot axes.
In walk-through programming, shown in Figure 2, the trainer physically moves the
robot through different steps of the job process. The robot learns which positions it
must move through, and which functions it must perform. Because it involves physical
contact with the robot, walk-through programming is done inside the work envelope
of the robot. This is extremely hazardous. To ensure worker safety, the robot must
be placed in manual mode. In manual mode a robot cannot move unless the trainer
holds down a pushbutton.
Lead-through and walk-through teaching methods are considered online. They require
the robot to remain "on" in order to learn. Off-line programming, shown in Figure 3,
allows the trainer to work from a remote location. The trainer writes a program and
downloads it into the robot. From there, the program can be refined with lead-
through or walk-through programming.
Figure 1. In lead-through programming the trainer
uses a remote teach pendant to program the robot.
Figure 2. In walk-through programming the trainer
physically moves the robot through different steps
of the job process.
Figure 3. In offline programming a trainer writes a
program from a remote location and downloads it
into the robot.
Industrial robots can be extremely fast and strong. When robot accidents occur, they can
result in serious injury, loss of limb, and even the death of a worker. Never enter the
robot’s work envelope unless it is absolutely necessary. The work envelope or work
cell is the defined area of space through which a robot can move. A worker within the
robot’s work envelope can be struck by the robot or crushed between equipment, as
shown in Figure 1. Even if you are familiar with the work pattern of the robot, do not
assume that you can predict its movements. Changes to the robot’s program, program
errors, and equipment malfunctions can cause sudden, unpredictable movements by the
robot.
If you must be inside the robot’s work envelope for installation, programming, or
maintenance, use a lockout/tagout key like the one in Figure 2 to prevent the robot
from starting up. Always read the robot’s user manual and make sure you are familiar
with the manufacturer’s safety guidelines. In addition, always wear personal protective
equipment (PPE) such as a hard hat, safety glasses, and steel-toed boots.
Workers must be trained and supervised in the operation, maintenance, and emergency
procedures of the robot. Workers should learn and comply with the guidelines from the
Occupational Safety and Health Administration (OSHA), the National Institute for
Occupational Safety and Health (NIOSH), and the American National Standards
Institute (ANSI). Safety devices such as security gates, pressure mats, alarms, and
emergency stop circuitry should be installed near the robot as well. Figure 3 shows a
robot secured behind a safety fence.
Figure 1. Within a robot’s work envelope, a
worker is in danger of being struck or crushed.
Figure 2. Use a lockout/tagout key whenever
you are inside the robot’s work envelope.
Figure 3. Install safety devices near the robot to
protect workers. [Courtesy of Kawasaki Robotics
(USA), Inc.]
For the past several years, sales of industrial robots have risen steadily. It is likely
that the use of robots in industry will continue to increase. In addition to various
manufacturing industries, the military is also expected to increase its use of robots.
One of the most important developments in robot technology is the addition of vision
to the robot’s abilities. Sensors and cameras on the robot allow it to see its
environment, as shown in Figure 1. When coupled with the memory provided by a
computer, vision allows the robot to find specific objects and features to determine
their position. This allows the robot to pick randomly positioned and oriented
objects.
As continuing advancements are made in developing artificial intelligence, there will be
more opportunities for robots to assist people. New types of robots may be
developed for personal use. Figure 2 shows a robot that can perform the simple
household chore of vacuuming. Someday, having your own robot may be as common
as having a cellular phone.
Figure 1. The addition of vision sensors, such as
cameras, is an important development in robot
technology.
Figure 2. This Roomba vacuum cleaner runs without
an operator. (Courtesy of Larry D. Moore)
As the use of robots increases in manufacturing, there will also be an increased need for
robot technicians to maintain the robots. Robot technicians may be required by an
employer to earn at least a two-year degree in robotics, engineering, or computer science.
Some of the day-to-day tasks performed by a robot technician include:
lAssisting the robot engineer in designing end-of-arm tools and accessory equipment
for specific tasks.
lInspecting electronic components and other robot parts for defects.
lInstalling and testing the robot.
lInstalling safety systems for the robot.
lTraining robot operators, troubleshooting problems, and providing technical support.
lDisassembling the robot for service and repair.
The working conditions for a robot technician can vary. A technician may be required to
travel to different locations. He or she may work on the robot in a clean, quiet test lab, like
the one in Figure 1, or in a dirty, noisy factory. If there is a problem with the robot or there
is an installation deadline, the technician may be required to work overtime.
Figure 1. The working conditions for a robot
technician can vary.
Robots improve worker safety by relieving workers from dangerous and tedious
jobs, as shown in Figure 1. For example, robots relieve workers from handling harsh
chemicals or radioactive parts. They can also help to prevent repetitive motion
injuries by performing repetitive tasks.
The growth of robotics means that there will be a greater demand for workers who
can operate and maintain robots. Robots also provide economic advantages to
employers. Robots do not take sick days or vacation days, and they never get tired.
They can work 24 hours a day without stopping. In addition, robots can repeat a
task many times without varying the quality or consistency of the work. This reduces
waste, increases productivity, and improves product quality. Moreover expenses
associated with defective parts and workers compensation claims are eliminated
when robots do the work.
Despite the many benefits of using robots in the workplace, there are some
disadvantages to using robots. In past studies, the Bureau of Labor and Statistics
predicted that increased automation in the workplace could lead workers to feel
stressed, lonely, and like they lost of control of the process. Moreover, installing
robots to perform menial tasks does not always mean that human workers are
advanced to higher-functioning tasks. Sometimes workers are merely shifted to a
different low-skill task.
The cost of buying and installing a robot like the one in Figure 2 can be very high.
There is an initial investment in support technology for the robot, and the robot
itself can cost $200,000 or more. It takes time to program and troubleshoot a robot
after it has been installed. In addition, workers must be trained to operate and
maintain the robot.
Figure 1. This robot can stack containers on a pallet
all day without getting bored, tired, or injured.
[Courtesy of Kawasaki Robotics (USA), Inc.]
Figure 2. The initial cost of installing this plastic
molding robot may be very high. [Courtesy of
Kawasaki Robotics (USA), Inc.]
An industrial robot is a programmable mechanical device used in place of a person to
perform dangerous or repetitive tasks. Industrial robots were first used in the 1960s.
One of the most common industrial applications for robots today is welding.
The basic components of a robot are the power supply, controller, teach pendant, axis
control module, input/output modules, and mechanical body. A robot’s body consists of
a base, shoulder, elbow, arm, wrist, and an end-of-arm-tool. Robots use different
coordinate systems to determine where to move. The Cartesian coordinate system
defines the location of a single point in three-dimensional space using X, Y, and Z axes.
World coordinates have the robot’s mounting base as a point of origin. Tool
coordinates have the tool at the end of the robot’s arm as the point of origin.
Robotic arms come in different styles. Articulated robots closely resemble a human arm.
Cartesian robots have prismatic joints only. Cylindrical robots have a combination of
revolute and prismatic joints that allow them to work well in round workspaces.
Spherical robots have a joint configuration that allows the robot to move in a desired
direction and then extend to reach an object. SCARA robots can move through X, Y, Z
coordinates and a fourth Theta Z coordinate.
Automatic guided vehicles can move freely about the workspace. Tow vehicles pull
trailers loaded with material. Unit load carriers have powered decks that lift and lower to
transport pallets loaded with material. Cart vehicles can load material like a unit load
carrier or pull it like a tow vehicle. Fork vehicles lift and lower materials.
Artificial intelligence is a computer software program that contains behavior rules for
robots. Robots are trained to do their jobs through different programming methods. In
lead-through programming the trainer uses a teach pendant to program the robot. In
walk-through programming, the trainer physically moves the robot through the job
process. In off-line programming the trainer writes a program remotely and downloads
it into the robot.
Robot accidents can result in serious injury and even the death of a worker. Therefore,
workers must learn the proper operation, maintenance, and emergency procedures of
the robot.
Figure 1. An industrial robot is composed of a
power supply, controller, axis control module, and
mechanical body.
Figure 2. A robotic arm typically include a base,
shoulder, arm, and end-effector.
Figure 3. Robot accidents can result in serious
injury and even the death of a worker.
Term Definition
alloy A uniform mixture of two or more materials, one of which must be a metal. Industrial robots are usually
composed of alloys.
American National Standards
Institute An organization that oversees industry standards for commercial products and services. ANSI provides
guidelines for manufacturing, installing, and safeguarding robotic systems.
articulated robot A type of robotic arm that closely resembles a human arm. The arm of an articulated robot has revolute joints
and the number of joints can vary.
artificial intelligence A computer software program that contains behavior rules for robots. Artificial intelligence is one of the
characteristics that distinguishes robots from other programmable machines.
assembly The process of fitting components together into a larger or completed part.
automatic guided vehicle An industrial robot that can move freely about the workspace. AGVs can take the form of carts, forklifts, or
tow vehicles.
axes The plural of axis. An axis is an imaginary straight line or circle used to describe the location or movement of
an object in the Cartesian coordinate system.
axis control module A component that allows a robot to move in different directions. The axis control module also controls the
velocity and torque of the robotic arm.
cabinet An enclosure containing a robot's controller, axis control module, input/output module, and power supplies.
camera A device used to capture still images, such as photographs, or moving images, such as videos. Cameras give
a robot vision.
cart vehicle A small AGV that can load material like a unit load carrier or pull it like a tow vehicle. Cart vehicles are usually
limited to loads of no more than 2,000 lbs. (907 kg).
Cartesian coordinate system A numerical system that describes the location of an object by numerically expressing its distance from a
fixed position along three linear axes.
Cartesian robot A type of robotic arm that has prismatic joints only. The linear movement of the joints gives the Cartesian
robot a highly rigid structure that allows it to lift heavy objects.
clean room A room in which temperature, humidity, and air pressure are controlled and maintained at a specific level.
controller The main device that processes information and carries out instructions in a robot. Also known as the CPU, or
processor.
cylindrical robot A type of robotic arm that has a combination of revolute and prismatic joints. Cylindrical robots work well in
round workspaces.
degrees of freedom The available ways a component can move in three-dimensional space. Robots typically have 3 to 6 degrees of
freedom.
dross A type of scum formed by oxidation at the surface of molten metals.
end-effector The end component of a robotic arm that is shaped like a hand or like a specialized tool. Also known as end-
of-arm tool (EOAT).
end-of-arm tool The end component of a robotic arm that is shaped like a hand or like a specialized tool. Also known as an
end-effector.
feeler A sensor on a robot that responds to touch or pressure.
fork vehicle A type of AGV that can lift and lower materials. Forks are available in different styles other than the standard
dual fork.
gripper A hand-shaped end-effector designed for seizing and holding.
industrial robot A programmable mechanical device that is used in place of a person to perform dangerous or repetitive tasks
with a high degree of accuracy.
input/output module The jack where an input/output device is physically connected to a robot. Inputs and outputs allow the robot
to interact with its environment.
integrated circuit A miniaturized electronic circuit. The development of integrated circuits helped to improve the performance of
industrial robots.
intelligence The ability to learn, reason, and solve problems.
joint The location at which two or more parts of a robotic arm make contact. Joints allow parts to move in different
directions.
lead-through programming A programming method in which a robot is placed in "teach mode" while the trainer uses a remote teach
pendant to manipulate the robot through the different steps of the job. Lead-through programming is the
most common programming method.
linear joint A joint that moves in a straight line across one axis. Also known as a prismatic joint.
linear movement Movement in a straight line across one axis.
link A fastener that joins or connects the parts of a robotic arm.
lockout/tagout A method of protecting employees from accidental robot startup through proper locking and labeling of
robots that are undergoing maintenance.
machine loading The process of loading raw materials into machinery for processing.
main power supply The power supply that provides voltage and current to a robot’s motor. A robot's main power supply is AC
run through a transformer.
manipulator A robotic arm. A manipulator is generally mounted on a platform or suspended from a track while the arm
reaches to various distances and locations.
material removal The process of removing substances or matter from a surface. Material removal processes include cutting,
grinding, deburring, deflashing, polishing, waterjet cutting, and routering.
materials handling The process of loading, unloading, placing, or manipulating material. Types of material handling include
machine tending, part transfer, packaging, and palletizing.
microcontroller A tiny computer that is self-sufficient.
National Institute for
Occupational Safety and
Health
The federal agency responsible for conducting research and making recommendations for the prevention of
work-related injury and illness. Also known as NIOSH.
Occupational Safety and
Health Administration A government agency that helps employers reduce injuries, illnesses, and deaths in the workplace. Also
known as OSHA.
off-line programming A programming method in which a trainer writes a program from a remote location and downloads it into a
robot. Off-line programming can be refined with lead-through or walk-through programming.
origin The fixed, central point in the Cartesian coordinate system. The origin has a numerical value of zero.
packaging The process of assembling containers and components for shipping and storage.
palletizing The process of placing and securing containers or objects on pallets.
part transfer A type of material handling in which parts are transferred from one location to another.
personal protective
equipment Any of various safety equipment that workers wear or use to prevent injury in the workplace. Safety glasses
are common personal protective equipment (PPE).
pick and place The process of picking up an object or part in one location and placing it in another location.
power supply unit A separate power supply that provides DC voltage to a robot’s outputs and controller.
prismatic joint A joint that moves in a straight line across one axis. Also known as a linear joint.
revolute joint A joint that rotates around more than one axis.
right-hand rule A quick reference that shows the X-, Y-, and Z-axes. A person displays his or her right hand, and the first
three fingers from the right each represent the X-, Y-, and Z-axis in order.
robot technician A person who installs, services, troubleshoots, maintains, and repairs robots and automated production
systems.
robotic arm An arm-shaped robot generally mounted on a platform or suspended from a track while the arm reaches to
various distances and locations. Also known as a manipulator.
SCARA robot Selective Compliance Arm for Robotic Assembly. A type of cylindrical robot that has 4 axes of movement: X,
Y, Z, and Theta Z.
sensor A device that detects the presence or absence of an object, or certain properties of that object, and provides
feedback. Sensors allow robots to interact with their environment.
servomotor A type of motor used in applications that require precise positioning. Servomotors can move loads in excess
of 50 hp.
spherical robot A type of robotic arm that has a joint configuration that allows the robot to move in a desired direction and
then extend to reach an object. A typical spherical robot has 4 to 6 revolute joints.
spray painting Applying paint with a sprayer. Spray paint applications include painting, sealing, and coating.
stepper motor A type of motor that uses a permanent magnetic field to rotate. Stepper motors can rotate forward or
reverse, but they cannot move large loads.
teach pendant A hand-held device that can be used to program a robot and control its movements.
Theta Z coordinate A rotating axis that corresponds to the angle around the z-axis of the tool at the end of a SCARA robot.
tool coordinates A coordinate system that uses the tool at the end of the robot's arm as the point of origin.
tow vehicle A type of AGV that pulls trailers loaded with material. Tow vehicles are capable of pulling extremely heavy
loads.
transformer A device that transfers electrical energy from one circuit to another, without changing the frequency.
transistor A tiny electrical device that amplifies electrical signals and switches current on and off.
tugger Another name for a tow vehicle. Tuggers pull trailers loaded with material.
unit load carrier A type of AGV that has powered decks that lift and lower to transport pallets loaded with material.
unmanned aerial vehicle A robotic airplane that can fly without an onboard pilot.
walk-through programming A programming method in which the trainer physically moves the robot through different steps of the job
process.
welding A joining process that uses heat, pressure, and/or chemicals to fuse two materials together permanently.
Robots are used for welding in the automotive industry.
work cell The defined area of space through which a robot can move. Also known as the work envelope.
work envelope The defined area of space through which a robot can move. Also known as the work cell.
world coordinates A coordinate system that uses the robot’s mounting base as a point of origin.
X-axis The linear axis representing side-to-side movement in a robot.
Y-axis The linear axis representing back and forth movement in a robot.
Z-axis The linear axis that represents up and down movement in a robot.
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Class Outline
Objectives
What Is a Robot?
The History of Robotics
The Industrial Applications of Robots
Basic Robot Components
The Parts of a Robot’s Body
Arm-Shaped Robots
Robot Coordinate Systems
Robotic Arm Configuration
Mobile Robots
Robots and Artificial Intelligence
Robot Teaching Methods
Robot Safety
Trends in Industrial Robotics
Careers in Robotics
The Pros and Cons of Robots
Summary
Lesson: 1/17
Objectives
Lesson: 2/17
What Is a Robot?
Lesson: 3/17
The History of Robotics
Lesson: 4/17
The Industrial Applications of Robots
Lesson: 5/17
Basic Robot Components
Lesson: 6/17
The Parts of a Robot’s Body
Lesson: 7/17
Arm-Shaped Robots
Lesson: 8/17
Robot Coordinate Systems
Lesson: 9/17
Robotic Arm Configuration
Lesson: 10/17
Mobile Robots
Lesson: 11/17
Robots and Artificial Intelligence
Lesson: 12/17
Robot Teaching Methods
Lesson: 13/17
Robot Safety
Lesson: 14/17
Trends in Industrial Robotics
Lesson: 15/17
Careers in Robotics
Lesson: 16/17
The Pros and Cons of Robots
Lesson: 17/17
Summary
Class Vocabulary
Intro to Robotics 110
lDefine a robot.
lDescribe the history of industrial robotics.
lDescribe the industrial applications of robots.
lDescribe the basic components of a robot.
lDescribe the different parts of a robot’s body.
lDescribe robotic arms.
lDescribe the coordinate systems used to program
a robot’s movement.
lDistinguish between different robotic arm
configurations.
lDescribe mobile robots.
lDescribe artificial intelligence for robots.
lDistinguish between different robot teaching
methods.
lDescribe safety precautions for working with
robots.
lDescribe present and future trends in industrial
robotics.
lDescribe careers in robotics.
lList the advantages and disadvantages of using
robots.
Figure 1. Robots can have different coordinates depending on the point of origin.
Figure 2. In lead-through programming, the trainer uses a remote teach pendant
to program the robot.
People have been fascinated by the idea of automated machines for centuries.
Devices propelled by water and steam were created as early as 350 B.C.E.
Throughout history scientists and inventors became increasingly interested in
creating machines that could duplicate human anatomy and movement. This
eventually gave rise to the modern industrial robot.
An industrial robot is a programmable mechanical device used in place of a person
to perform dangerous or repetitive tasks with a high degree of accuracy. Not all
programmable machines are robots, however. The laser welding machine in Figure 1
is a robot, but a programmable VCR is not. A robot must be able to move on its
own, sense information about its environment, and use that information to
accomplish a programmed task. Robots can change their behavior in response to
their environment while automated machines simply follow instructions.
Robots can be large or small and they come in many shapes. They are capable of
lifting very heavy objects and performing repetitive tasks for long periods of time
without stopping. Figure 2 shows a machine tending robot. In this class you will
learn the classifications, characteristics, and functions of industrial robots. You will
also learn basic safety precautions for working with robots.
Figure 1. This arc welding robot moves on its own and
uses a vision sensor to accomplish its task. [Courtesy
of Kawasaki Robotics (USA), Inc.]
Figure 2. This machine tending robot can work for
many hours without getting bored or tired. [Courtesy
of Kawasaki Robotics (USA), Inc.]
Industrial robots were first used in the 1960s. U.S. companies were looking for cheap
labor, and robotics was a potential solution. However, early robots were bulky, slow, and
inefficient. The amount of human effort required to keep the robots running cancelled out
any cost advantage that the robots provided. In the end, manufacturers realized that
robots could never fully replace people. Instead, robots simply became another part of
factory technology. The welding robots in Figure 1 are very good at their job, but they
do not have the flexibility and intelligence of a human worker.
The use of industrial robots increased significantly after stepper motors became smaller
and stronger and AC servomotors became more affordable. These developments, along
with the use of transistors and integrated circuits, improved the productivity of
robots.
Today’s robots are extremely smart and versatile. In the military, planes known as
unmanned aerial vehicles (UAVs) can fly without an onboard pilot. Robots are also
used for exploration. NASA makes extensive use of small robotic vehicles, like the rover
in Figure 2, to explore other planets.
Figure 1. Robots are an important part of factory
technology, but they will never fully replace
people.
Figure 2. NASA uses mobile robots like this Mars
rover to explore other planets.
In industry, robots perform a wide variety of tasks. They are often used to handle
materials that are extremely hot or heavy. For example, robots are used to remove
a waste product called dross from molten metal baths. A skimmer full of dross can
weigh up to 33 lbs (72.2 kg). In addition, metal baths can reach temperatures that
exceed 800°F (426°C). For a human, skimming dross would be a hot, exhausting,
and potentially dangerous job. But a robot can perform this work quickly and easily
without being harmed.
One of the most common industrial applications for robots is welding, shown in
Figure 1. Robots are ideal for welding because of their high speed, the uniform
quality of their work, and their ability to repeat tasks without wearing out. The
automotive industry is one of the largest users of robotic welders.
Spray painting, shown in Figure 2, is another common use for robots. The highly
repetitive motions required in spray painting are well-suited to robots. Robots can
paint quickly and efficiently with nearly perfect quality. Because of their speed and
efficiency, robots also use less paint.
The newspaper industry makes extensive use of robots for a type of materials
handling called palletizing. The robots load and unload stacks of newspapers onto
movable platforms called pallets. Other industrial uses for robots include
packaging, part transfer, pick and place, machine loading, material removal,
and assembly. An assembly robot is shown in Figure 3.
Robots are also an ideal resource for working with integrated circuits in a clean
room. ICs are extremely sensitive to dust and dirt and other types of debris.
Because robots have no skin, hair, or breath, they do not contaminate the clean
room environment.
Figure 1. Welding is a common industrial robot
application. [Courtesy of Kawasaki Robotics (USA),
Inc.]
Figure 2. This spray painting robot works quickly and
efficiently with nearly perfect quality. [Courtesy of
Kawasaki Robotics (USA), Inc.]
Figure 3. An assembly robot. [Courtesy of Kawasaki
Robotics (USA), Inc.]
Figure 1 illustrates the basic components that make up an industrial robot. These
components are the power supply, controller, teach pendant, axis control module,
input/output modules, and mechanical body. The main power supply to the robot is
AC run through a transformer. This main power supply provides voltage and current
to the robot's motor. The motor can be servo or non-servo. Servomotors, like the
one in Figure 2, are used for applications such as pick and place that require the robot
to move to a precise location.
In addition to the main power supply, there are separate power supplies to the robot
that can be located in a cabinet, shown in Figure 3, or in a power supply unit (PSU).
The PSU provides DC voltage to the robot's outputs and controller. Robots can be also
be powered by batteries, solar panels, springs, hydraulics, and pneumatics. However,
most industrial robots use a plug-in power supply.
In order to run its program and interface with inputs and outputs, a robot must have a
controller. The controller can be located in a cabinet that is external to the robot, or it
can be a microcontroller (MCU) inside the robot. A hand-held remote control called a
teach pendant is connected to the controller and is used to program the robot. Teach
pendants are connected to the controller by a cable.
The axis control module, which is also connected to the controller, allows the robot
to move through the coordinates specified by its program. The axis control module
also controls the speed at which the robot's body moves. Figure 1. An industrial robot is composed of a
power supply, controller, axis control module, and
mechanical body.
Figure 2. Servomotors are used for robotic
applications that require precise positioning.
Figure 3. A cabinet holding the controller and teach
pendant. [Courtesy of Kawasaki Robotics (USA),
Inc.]
A robot’s body consists of different mechanical parts that are typically made from some
type of metal or alloy such as steel, cast iron, or aluminum. For a robotic arm, the body
parts can include a base, shoulder, elbow, arm, wrist, and even fingers. Figure 1 shows a
basic robotic arm. Links and joints within the robotic arm allow the robot to move in
different directions.
An end-of-arm tool (EOAT), also known as the end-effector, is attached to the end
joint of the arm. End-effectors can be shaped like hands, like the one in Figure 2, or they
can be highly specialized tools, like the grinder in Figure 3. Hand-shaped effectors are
called grippers. Grippers come in many shapes and sizes. Tools also come in a wide
variety and are designed for specific tasks such as welding or grinding.
Effectors are activated in response to signals that the robot sends and receives through
an input/output module. Input signals from sensors on or near the robot provide
information about its surroundings. Output signals are then sent to the robotic arm to
activate the work tool. Figure 1. A robotic arm typically includes a base,
shoulder, arm, and end-effector.
Figure 2. A gripper is an end-effector that is
shaped like a hand.
Figure 3. This robot is using an end-of-arm tool
that is specifically for grinding.
There are two major classes of robots: fixed robotic arms and mobile robotic vehicles.
The robotic arm in Figure 1 is also known as a manipulator. A manipulator resembles
a human arm with a shoulder, elbow, wrist, and fingers. The manipulator is generally
mounted on a platform or suspended from a track while the arm reaches to various
distances and locations.
The joints on a robotic arm can move in different directions along particular axes. An
axis is an imaginary line or circle along which a robotic component can move. The axes
of a robotic joint can allow movement side-to-side, up and down, in and out, or in a
circle. Collectively these axes represent the robot's degrees of freedom.
Robotic arms have two basic types of joints. Prismatic joints, also known as linear
joints, slide in a straight line across one axis. A revolute joint, on the other hand,
gives a robotic arm a wide range of movement. Revolute joints rotate almost
exclusively around one axis like a shaft in a bearing. To make a single joint rotate
around more than one axis requires a ball-and-socket type of bearing and drive. This is
hard to build, has accuracy and wear issues, and is difficult to drive. The robot in
Figure 2 has two prismatic joints and one revolute joint.
Figure 1. A robotic arm is generally mounted on a
platform from which it reaches to various distances
and locations.
Figure 2. Prismatic joints slide in a straight line
across one axis while revolute joints rotate around
an axis.
In order to tell a robot where to move, an operator must be familiar with the
Cartesian coordinate system. The Cartesian coordinate system defines the
location of a single point in three-dimensional space using three axes. The X-axis,
Y-axis, and Z-axis join together like the corner of a box. The point where all the
axes meet is the origin. The X and Y axes are horizontal, with one axis going in
and out, and one axis going side-to-side. The Z axis goes up and down.
An effective way to picture the three Cartesian axes is by using the right-hand
rule. Place your hand on a table or a bench. Turn your right palm up, and then
extend only the thumb and forefinger. This forms an "L," with the middle finger up
to the ceiling, as shown in Figure 1. The thumb is the X-axis, the forefinger is the
Y-axis, and the elevated center finger is the Z-axis.
The positions of a robot are referenced according to different coordinate systems.
The coordinate systems vary depending on the point of origin. World coordinates
use the robot’s mounting base as a point of origin, as shown in Figure 2. Tool
coordinates use the tool at the end of the robot’s arm as the point of origin. Tool
coordinates are used for teaching the robot where to move. With tool coordinates,
the X, Y, and Z axes are set from the tool’s point of view. Figure 1. Using the right-hand rule, the thumb is the
X-axis, the forefinger is the Y-axis, and the elevated
center finger is the Z-axis
Figure 2. A robot can have different sets of
coordinates.
Robotic arms come in a variety of styles. Articulated robots, like the one illustrated
in Figure 1, most closely resemble a human arm. The arm of an articulated robot has
revolute joints, and the number of joints can vary. Articulated robots are very good
at picking up small objects.
A Cartesian robot, shown in Figure 2, has prismatic joints only. The linear
movement of the joints gives the Cartesian robot a highly rigid structure that allows
it to lift heavy objects. Cartesian robots are also extremely precise because of the
accuracy and arrangements of the prismatic bearings. Cartesian robots can move
through X, Y, and Z axes. The length of each axis can be adjusted depending on the
application. Cartesian robots are used for assembly and injection molding
applications.
Cylindrical robots have a combination of revolute and prismatic joints that allow
them to work well in round workspaces. Spherical robots, on the other hand, have a
joint configuration that allows the robot to move in a desired direction and then
extend to reach an object. Figure 3 shows a spherical robot. Spherical robots are
used for welding and material handling. A typical spherical robot has 4 to 6 revolute
joints.
SCARA robots are a type of cylindrical robot. SCARA stands for Selective Compliance
Arm for Robotic Assembly. The SCARA robot illustrated in Figure 4 has four axes of
movement. It can move through X, Y, Z coordinates and a fourth Theta Z
coordinate. Theta Z is a rotating axis that corresponds to the angle around the z-
axis of the tool at the end of the SCARA robot. SCARA robots are often used for
inserting electronic components into circuit boards. SCARA robots generally have
three parallel revolute joints and two parallel prismatic joints that are both in the Z
direction.
Figure 1. An articulated robot has revolute joints
only.
Figure 2. A Cartesian robot has prismatic joints
only.
Figure 3. This spherical robot can turn around on its
base and reach for an object.
Figure 4. SCARA robots can move through X, Y, Z
coordinates and a fourth Theta Z coordinate
corresponding to the end-effector.
The robotic arm is the most common type of industrial robot. However, there is a second
type of industrial robot known as the automatic guided vehicle (AGV). Unlike a robotic
arm, an AGV can move freely about the workspace. Instead of having a driver for
navigation, the AGV uses light reflectors, colored tape, or wires that are embedded in the
floor to guide it through a predetermined route.
There are four types of AGVs:
lTow vehicles, also known as tuggers (Figure 1), pull trailers loaded with material.
Tow vehicles are capable of pulling extremely heavy loads, some weighing up to
60,000 lbs. (27,215 kg). Tow vehicles do not load the materials; they simply
transport them.
lUnit load carriers (Figure 2) have powered decks that lift and lower to transport
pallets loaded with material.
lCart vehicles (Figure 3) are small, relatively inexpensive AGVs that can load material
like a unit load carrier or pull it like a tow vehicle. However, cart vehicles are usually
limited to loads of no more than 2,000 lbs. (907 kg).
lFork vehicles (Figure 4) lift and lower materials. Their load capacity can range from
1,200 to 5,000 lbs. (544 to 2,267 kg). Forks are available in different styles other
than the standard dual fork.
AGVs are extremely flexible in the distance and direction that they can move. You can find
AGVs in automotive, printing, chemical, medical and pharmaceutical, food and beverage,
distribution, paper, manufacturing, and warehousing applications.
Figure 1. A tow vehicle is capable of pulling
extremely heavy loads.
Figure 2. A unit load carrier has powered decks
that lift and lower.
Figure 3. A cart vehicle cannot pull loads
greater than 2,000 lbs. (907 kg).
Figure 4. Fork vehicles primarily lift and lower
materials.
In order to be considered a robot, a machine must have some form of artificial
intelligence. Artificial intelligence is simply a computer software program that contains
behavior rules, as shown in Figure 1. These rules tell the robot how to act as it learns
how to perform its job. For example, a robot could be programmed to move toward a
light source when light is detected by its photosensors. Or it could be programmed to
move away from any objects that come into contact with the robot’s feelers. Figure 2
shows how a robot learns to adjust its path after colliding with an object.
Like human intelligence, an artificial intelligence program controls different levels of
behavior. The lowest, most primitive level of artificial intelligence simply allows the robot
to move its mechanical parts. The next level controls the robot’s reflexes so it can
respond to its environment and make decisions based on the information detected by
its sensors. The highest level of artificial intelligence is devoted to the robot’s memory
and problem-solving abilities.
Figure 1. Artificial intelligence is simply a computer
software program. [Courtesy of Kawasaki Robotics
(USA), Inc.]
Figure 2. After colliding with an object, this robot
learns to adjust its path. (Courtesy of Kawasaki
Robotics (USA), Inc.)
Like a human worker, a robot must be trained to do its job correctly. While it is
possible for some robots to simply learn on their own by trial and error, most robots
are taught by humans. The three main methods for teaching robots are lead-through
programming, walk-through programming, and off-line programming.
In lead-through programming, shown in Figure 1, the robot is placed in "teach
mode" while the trainer uses a remote teach pendant to manipulate the robot through
the different steps of the job. This is the most common programming method. The
robot is moved manually via the teach pendant, which controls the robot axes.
In walk-through programming, shown in Figure 2, the trainer physically moves the
robot through different steps of the job process. The robot learns which positions it
must move through, and which functions it must perform. Because it involves physical
contact with the robot, walk-through programming is done inside the work envelope
of the robot. This is extremely hazardous. To ensure worker safety, the robot must
be placed in manual mode. In manual mode a robot cannot move unless the trainer
holds down a pushbutton.
Lead-through and walk-through teaching methods are considered online. They require
the robot to remain "on" in order to learn. Off-line programming, shown in Figure 3,
allows the trainer to work from a remote location. The trainer writes a program and
downloads it into the robot. From there, the program can be refined with lead-
through or walk-through programming.
Figure 1. In lead-through programming the trainer
uses a remote teach pendant to program the robot.
Figure 2. In walk-through programming the trainer
physically moves the robot through different steps
of the job process.
Figure 3. In offline programming a trainer writes a
program from a remote location and downloads it
into the robot.
Industrial robots can be extremely fast and strong. When robot accidents occur, they can
result in serious injury, loss of limb, and even the death of a worker. Never enter the
robot’s work envelope unless it is absolutely necessary. The work envelope or work
cell is the defined area of space through which a robot can move. A worker within the
robot’s work envelope can be struck by the robot or crushed between equipment, as
shown in Figure 1. Even if you are familiar with the work pattern of the robot, do not
assume that you can predict its movements. Changes to the robot’s program, program
errors, and equipment malfunctions can cause sudden, unpredictable movements by the
robot.
If you must be inside the robot’s work envelope for installation, programming, or
maintenance, use a lockout/tagout key like the one in Figure 2 to prevent the robot
from starting up. Always read the robot’s user manual and make sure you are familiar
with the manufacturer’s safety guidelines. In addition, always wear personal protective
equipment (PPE) such as a hard hat, safety glasses, and steel-toed boots.
Workers must be trained and supervised in the operation, maintenance, and emergency
procedures of the robot. Workers should learn and comply with the guidelines from the
Occupational Safety and Health Administration (OSHA), the National Institute for
Occupational Safety and Health (NIOSH), and the American National Standards
Institute (ANSI). Safety devices such as security gates, pressure mats, alarms, and
emergency stop circuitry should be installed near the robot as well. Figure 3 shows a
robot secured behind a safety fence.
Figure 1. Within a robot’s work envelope, a
worker is in danger of being struck or crushed.
Figure 2. Use a lockout/tagout key whenever
you are inside the robot’s work envelope.
Figure 3. Install safety devices near the robot to
protect workers. [Courtesy of Kawasaki Robotics
(USA), Inc.]
For the past several years, sales of industrial robots have risen steadily. It is likely
that the use of robots in industry will continue to increase. In addition to various
manufacturing industries, the military is also expected to increase its use of robots.
One of the most important developments in robot technology is the addition of vision
to the robot’s abilities. Sensors and cameras on the robot allow it to see its
environment, as shown in Figure 1. When coupled with the memory provided by a
computer, vision allows the robot to find specific objects and features to determine
their position. This allows the robot to pick randomly positioned and oriented
objects.
As continuing advancements are made in developing artificial intelligence, there will be
more opportunities for robots to assist people. New types of robots may be
developed for personal use. Figure 2 shows a robot that can perform the simple
household chore of vacuuming. Someday, having your own robot may be as common
as having a cellular phone.
Figure 1. The addition of vision sensors, such as
cameras, is an important development in robot
technology.
Figure 2. This Roomba vacuum cleaner runs without
an operator. (Courtesy of Larry D. Moore)
As the use of robots increases in manufacturing, there will also be an increased need for
robot technicians to maintain the robots. Robot technicians may be required by an
employer to earn at least a two-year degree in robotics, engineering, or computer science.
Some of the day-to-day tasks performed by a robot technician include:
lAssisting the robot engineer in designing end-of-arm tools and accessory equipment
for specific tasks.
lInspecting electronic components and other robot parts for defects.
lInstalling and testing the robot.
lInstalling safety systems for the robot.
lTraining robot operators, troubleshooting problems, and providing technical support.
lDisassembling the robot for service and repair.
The working conditions for a robot technician can vary. A technician may be required to
travel to different locations. He or she may work on the robot in a clean, quiet test lab, like
the one in Figure 1, or in a dirty, noisy factory. If there is a problem with the robot or there
is an installation deadline, the technician may be required to work overtime.
Figure 1. The working conditions for a robot
technician can vary.
Robots improve worker safety by relieving workers from dangerous and tedious
jobs, as shown in Figure 1. For example, robots relieve workers from handling harsh
chemicals or radioactive parts. They can also help to prevent repetitive motion
injuries by performing repetitive tasks.
The growth of robotics means that there will be a greater demand for workers who
can operate and maintain robots. Robots also provide economic advantages to
employers. Robots do not take sick days or vacation days, and they never get tired.
They can work 24 hours a day without stopping. In addition, robots can repeat a
task many times without varying the quality or consistency of the work. This reduces
waste, increases productivity, and improves product quality. Moreover expenses
associated with defective parts and workers compensation claims are eliminated
when robots do the work.
Despite the many benefits of using robots in the workplace, there are some
disadvantages to using robots. In past studies, the Bureau of Labor and Statistics
predicted that increased automation in the workplace could lead workers to feel
stressed, lonely, and like they lost of control of the process. Moreover, installing
robots to perform menial tasks does not always mean that human workers are
advanced to higher-functioning tasks. Sometimes workers are merely shifted to a
different low-skill task.
The cost of buying and installing a robot like the one in Figure 2 can be very high.
There is an initial investment in support technology for the robot, and the robot
itself can cost $200,000 or more. It takes time to program and troubleshoot a robot
after it has been installed. In addition, workers must be trained to operate and
maintain the robot.
Figure 1. This robot can stack containers on a pallet
all day without getting bored, tired, or injured.
[Courtesy of Kawasaki Robotics (USA), Inc.]
Figure 2. The initial cost of installing this plastic
molding robot may be very high. [Courtesy of
Kawasaki Robotics (USA), Inc.]
An industrial robot is a programmable mechanical device used in place of a person to
perform dangerous or repetitive tasks. Industrial robots were first used in the 1960s.
One of the most common industrial applications for robots today is welding.
The basic components of a robot are the power supply, controller, teach pendant, axis
control module, input/output modules, and mechanical body. A robot’s body consists of
a base, shoulder, elbow, arm, wrist, and an end-of-arm-tool. Robots use different
coordinate systems to determine where to move. The Cartesian coordinate system
defines the location of a single point in three-dimensional space using X, Y, and Z axes.
World coordinates have the robot’s mounting base as a point of origin. Tool
coordinates have the tool at the end of the robot’s arm as the point of origin.
Robotic arms come in different styles. Articulated robots closely resemble a human arm.
Cartesian robots have prismatic joints only. Cylindrical robots have a combination of
revolute and prismatic joints that allow them to work well in round workspaces.
Spherical robots have a joint configuration that allows the robot to move in a desired
direction and then extend to reach an object. SCARA robots can move through X, Y, Z
coordinates and a fourth Theta Z coordinate.
Automatic guided vehicles can move freely about the workspace. Tow vehicles pull
trailers loaded with material. Unit load carriers have powered decks that lift and lower to
transport pallets loaded with material. Cart vehicles can load material like a unit load
carrier or pull it like a tow vehicle. Fork vehicles lift and lower materials.
Artificial intelligence is a computer software program that contains behavior rules for
robots. Robots are trained to do their jobs through different programming methods. In
lead-through programming the trainer uses a teach pendant to program the robot. In
walk-through programming, the trainer physically moves the robot through the job
process. In off-line programming the trainer writes a program remotely and downloads
it into the robot.
Robot accidents can result in serious injury and even the death of a worker. Therefore,
workers must learn the proper operation, maintenance, and emergency procedures of
the robot.
Figure 1. An industrial robot is composed of a
power supply, controller, axis control module, and
mechanical body.
Figure 2. A robotic arm typically include a base,
shoulder, arm, and end-effector.
Figure 3. Robot accidents can result in serious
injury and even the death of a worker.
Term Definition
alloy A uniform mixture of two or more materials, one of which must be a metal. Industrial robots are usually
composed of alloys.
American National Standards
Institute An organization that oversees industry standards for commercial products and services. ANSI provides
guidelines for manufacturing, installing, and safeguarding robotic systems.
articulated robot A type of robotic arm that closely resembles a human arm. The arm of an articulated robot has revolute joints
and the number of joints can vary.
artificial intelligence A computer software program that contains behavior rules for robots. Artificial intelligence is one of the
characteristics that distinguishes robots from other programmable machines.
assembly The process of fitting components together into a larger or completed part.
automatic guided vehicle An industrial robot that can move freely about the workspace. AGVs can take the form of carts, forklifts, or
tow vehicles.
axes The plural of axis. An axis is an imaginary straight line or circle used to describe the location or movement of
an object in the Cartesian coordinate system.
axis control module A component that allows a robot to move in different directions. The axis control module also controls the
velocity and torque of the robotic arm.
cabinet An enclosure containing a robot's controller, axis control module, input/output module, and power supplies.
camera A device used to capture still images, such as photographs, or moving images, such as videos. Cameras give
a robot vision.
cart vehicle A small AGV that can load material like a unit load carrier or pull it like a tow vehicle. Cart vehicles are usually
limited to loads of no more than 2,000 lbs. (907 kg).
Cartesian coordinate system A numerical system that describes the location of an object by numerically expressing its distance from a
fixed position along three linear axes.
Cartesian robot A type of robotic arm that has prismatic joints only. The linear movement of the joints gives the Cartesian
robot a highly rigid structure that allows it to lift heavy objects.
clean room A room in which temperature, humidity, and air pressure are controlled and maintained at a specific level.
controller The main device that processes information and carries out instructions in a robot. Also known as the CPU, or
processor.
cylindrical robot A type of robotic arm that has a combination of revolute and prismatic joints. Cylindrical robots work well in
round workspaces.
degrees of freedom The available ways a component can move in three-dimensional space. Robots typically have 3 to 6 degrees of
freedom.
dross A type of scum formed by oxidation at the surface of molten metals.
end-effector The end component of a robotic arm that is shaped like a hand or like a specialized tool. Also known as end-
of-arm tool (EOAT).
end-of-arm tool The end component of a robotic arm that is shaped like a hand or like a specialized tool. Also known as an
end-effector.
feeler A sensor on a robot that responds to touch or pressure.
fork vehicle A type of AGV that can lift and lower materials. Forks are available in different styles other than the standard
dual fork.
gripper A hand-shaped end-effector designed for seizing and holding.
industrial robot A programmable mechanical device that is used in place of a person to perform dangerous or repetitive tasks
with a high degree of accuracy.
input/output module The jack where an input/output device is physically connected to a robot. Inputs and outputs allow the robot
to interact with its environment.
integrated circuit A miniaturized electronic circuit. The development of integrated circuits helped to improve the performance of
industrial robots.
intelligence The ability to learn, reason, and solve problems.
joint The location at which two or more parts of a robotic arm make contact. Joints allow parts to move in different
directions.
lead-through programming A programming method in which a robot is placed in "teach mode" while the trainer uses a remote teach
pendant to manipulate the robot through the different steps of the job. Lead-through programming is the
most common programming method.
linear joint A joint that moves in a straight line across one axis. Also known as a prismatic joint.
linear movement Movement in a straight line across one axis.
link A fastener that joins or connects the parts of a robotic arm.
lockout/tagout A method of protecting employees from accidental robot startup through proper locking and labeling of
robots that are undergoing maintenance.
machine loading The process of loading raw materials into machinery for processing.
main power supply The power supply that provides voltage and current to a robot’s motor. A robot's main power supply is AC
run through a transformer.
manipulator A robotic arm. A manipulator is generally mounted on a platform or suspended from a track while the arm
reaches to various distances and locations.
material removal The process of removing substances or matter from a surface. Material removal processes include cutting,
grinding, deburring, deflashing, polishing, waterjet cutting, and routering.
materials handling The process of loading, unloading, placing, or manipulating material. Types of material handling include
machine tending, part transfer, packaging, and palletizing.
microcontroller A tiny computer that is self-sufficient.
National Institute for
Occupational Safety and
Health
The federal agency responsible for conducting research and making recommendations for the prevention of
work-related injury and illness. Also known as NIOSH.
Occupational Safety and
Health Administration A government agency that helps employers reduce injuries, illnesses, and deaths in the workplace. Also
known as OSHA.
off-line programming A programming method in which a trainer writes a program from a remote location and downloads it into a
robot. Off-line programming can be refined with lead-through or walk-through programming.
origin The fixed, central point in the Cartesian coordinate system. The origin has a numerical value of zero.
packaging The process of assembling containers and components for shipping and storage.
palletizing The process of placing and securing containers or objects on pallets.
part transfer A type of material handling in which parts are transferred from one location to another.
personal protective
equipment Any of various safety equipment that workers wear or use to prevent injury in the workplace. Safety glasses
are common personal protective equipment (PPE).
pick and place The process of picking up an object or part in one location and placing it in another location.
power supply unit A separate power supply that provides DC voltage to a robot’s outputs and controller.
prismatic joint A joint that moves in a straight line across one axis. Also known as a linear joint.
revolute joint A joint that rotates around more than one axis.
right-hand rule A quick reference that shows the X-, Y-, and Z-axes. A person displays his or her right hand, and the first
three fingers from the right each represent the X-, Y-, and Z-axis in order.
robot technician A person who installs, services, troubleshoots, maintains, and repairs robots and automated production
systems.
robotic arm An arm-shaped robot generally mounted on a platform or suspended from a track while the arm reaches to
various distances and locations. Also known as a manipulator.
SCARA robot Selective Compliance Arm for Robotic Assembly. A type of cylindrical robot that has 4 axes of movement: X,
Y, Z, and Theta Z.
sensor A device that detects the presence or absence of an object, or certain properties of that object, and provides
feedback. Sensors allow robots to interact with their environment.
servomotor A type of motor used in applications that require precise positioning. Servomotors can move loads in excess
of 50 hp.
spherical robot A type of robotic arm that has a joint configuration that allows the robot to move in a desired direction and
then extend to reach an object. A typical spherical robot has 4 to 6 revolute joints.
spray painting Applying paint with a sprayer. Spray paint applications include painting, sealing, and coating.
stepper motor A type of motor that uses a permanent magnetic field to rotate. Stepper motors can rotate forward or
reverse, but they cannot move large loads.
teach pendant A hand-held device that can be used to program a robot and control its movements.
Theta Z coordinate A rotating axis that corresponds to the angle around the z-axis of the tool at the end of a SCARA robot.
tool coordinates A coordinate system that uses the tool at the end of the robot's arm as the point of origin.
tow vehicle A type of AGV that pulls trailers loaded with material. Tow vehicles are capable of pulling extremely heavy
loads.
transformer A device that transfers electrical energy from one circuit to another, without changing the frequency.
transistor A tiny electrical device that amplifies electrical signals and switches current on and off.
tugger Another name for a tow vehicle. Tuggers pull trailers loaded with material.
unit load carrier A type of AGV that has powered decks that lift and lower to transport pallets loaded with material.
unmanned aerial vehicle A robotic airplane that can fly without an onboard pilot.
walk-through programming A programming method in which the trainer physically moves the robot through different steps of the job
process.
welding A joining process that uses heat, pressure, and/or chemicals to fuse two materials together permanently.
Robots are used for welding in the automotive industry.
work cell The defined area of space through which a robot can move. Also known as the work envelope.
work envelope The defined area of space through which a robot can move. Also known as the work cell.
world coordinates A coordinate system that uses the robot’s mounting base as a point of origin.
X-axis The linear axis representing side-to-side movement in a robot.
Y-axis The linear axis representing back and forth movement in a robot.
Z-axis The linear axis that represents up and down movement in a robot.
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Class Outline
Objectives
What Is a Robot?
The History of Robotics
The Industrial Applications of Robots
Basic Robot Components
The Parts of a Robot’s Body
Arm-Shaped Robots
Robot Coordinate Systems
Robotic Arm Configuration
Mobile Robots
Robots and Artificial Intelligence
Robot Teaching Methods
Robot Safety
Trends in Industrial Robotics
Careers in Robotics
The Pros and Cons of Robots
Summary
Lesson: 1/17
Objectives
Lesson: 2/17
What Is a Robot?
Lesson: 3/17
The History of Robotics
Lesson: 4/17
The Industrial Applications of Robots
Lesson: 5/17
Basic Robot Components
Lesson: 6/17
The Parts of a Robot’s Body
Lesson: 7/17
Arm-Shaped Robots
Lesson: 8/17
Robot Coordinate Systems
Lesson: 9/17
Robotic Arm Configuration
Lesson: 10/17
Mobile Robots
Lesson: 11/17
Robots and Artificial Intelligence
Lesson: 12/17
Robot Teaching Methods
Lesson: 13/17
Robot Safety
Lesson: 14/17
Trends in Industrial Robotics
Lesson: 15/17
Careers in Robotics
Lesson: 16/17
The Pros and Cons of Robots
Lesson: 17/17
Summary
Class Vocabulary
Intro to Robotics 110
lDefine a robot.
lDescribe the history of industrial robotics.
lDescribe the industrial applications of robots.
lDescribe the basic components of a robot.
lDescribe the different parts of a robot’s body.
lDescribe robotic arms.
lDescribe the coordinate systems used to program
a robot’s movement.
lDistinguish between different robotic arm
configurations.
lDescribe mobile robots.
lDescribe artificial intelligence for robots.
lDistinguish between different robot teaching
methods.
lDescribe safety precautions for working with
robots.
lDescribe present and future trends in industrial
robotics.
lDescribe careers in robotics.
lList the advantages and disadvantages of using
robots.
Figure 1. Robots can have different coordinates depending on the point of origin.
Figure 2. In lead-through programming, the trainer uses a remote teach pendant
to program the robot.
People have been fascinated by the idea of automated machines for centuries.
Devices propelled by water and steam were created as early as 350 B.C.E.
Throughout history scientists and inventors became increasingly interested in
creating machines that could duplicate human anatomy and movement. This
eventually gave rise to the modern industrial robot.
An industrial robot is a programmable mechanical device used in place of a person
to perform dangerous or repetitive tasks with a high degree of accuracy. Not all
programmable machines are robots, however. The laser welding machine in Figure 1
is a robot, but a programmable VCR is not. A robot must be able to move on its
own, sense information about its environment, and use that information to
accomplish a programmed task. Robots can change their behavior in response to
their environment while automated machines simply follow instructions.
Robots can be large or small and they come in many shapes. They are capable of
lifting very heavy objects and performing repetitive tasks for long periods of time
without stopping. Figure 2 shows a machine tending robot. In this class you will
learn the classifications, characteristics, and functions of industrial robots. You will
also learn basic safety precautions for working with robots.
Figure 1. This arc welding robot moves on its own and
uses a vision sensor to accomplish its task. [Courtesy
of Kawasaki Robotics (USA), Inc.]
Figure 2. This machine tending robot can work for
many hours without getting bored or tired. [Courtesy
of Kawasaki Robotics (USA), Inc.]
Industrial robots were first used in the 1960s. U.S. companies were looking for cheap
labor, and robotics was a potential solution. However, early robots were bulky, slow, and
inefficient. The amount of human effort required to keep the robots running cancelled out
any cost advantage that the robots provided. In the end, manufacturers realized that
robots could never fully replace people. Instead, robots simply became another part of
factory technology. The welding robots in Figure 1 are very good at their job, but they
do not have the flexibility and intelligence of a human worker.
The use of industrial robots increased significantly after stepper motors became smaller
and stronger and AC servomotors became more affordable. These developments, along
with the use of transistors and integrated circuits, improved the productivity of
robots.
Today’s robots are extremely smart and versatile. In the military, planes known as
unmanned aerial vehicles (UAVs) can fly without an onboard pilot. Robots are also
used for exploration. NASA makes extensive use of small robotic vehicles, like the rover
in Figure 2, to explore other planets.
Figure 1. Robots are an important part of factory
technology, but they will never fully replace
people.
Figure 2. NASA uses mobile robots like this Mars
rover to explore other planets.
In industry, robots perform a wide variety of tasks. They are often used to handle
materials that are extremely hot or heavy. For example, robots are used to remove
a waste product called dross from molten metal baths. A skimmer full of dross can
weigh up to 33 lbs (72.2 kg). In addition, metal baths can reach temperatures that
exceed 800°F (426°C). For a human, skimming dross would be a hot, exhausting,
and potentially dangerous job. But a robot can perform this work quickly and easily
without being harmed.
One of the most common industrial applications for robots is welding, shown in
Figure 1. Robots are ideal for welding because of their high speed, the uniform
quality of their work, and their ability to repeat tasks without wearing out. The
automotive industry is one of the largest users of robotic welders.
Spray painting, shown in Figure 2, is another common use for robots. The highly
repetitive motions required in spray painting are well-suited to robots. Robots can
paint quickly and efficiently with nearly perfect quality. Because of their speed and
efficiency, robots also use less paint.
The newspaper industry makes extensive use of robots for a type of materials
handling called palletizing. The robots load and unload stacks of newspapers onto
movable platforms called pallets. Other industrial uses for robots include
packaging, part transfer, pick and place, machine loading, material removal,
and assembly. An assembly robot is shown in Figure 3.
Robots are also an ideal resource for working with integrated circuits in a clean
room. ICs are extremely sensitive to dust and dirt and other types of debris.
Because robots have no skin, hair, or breath, they do not contaminate the clean
room environment.
Figure 1. Welding is a common industrial robot
application. [Courtesy of Kawasaki Robotics (USA),
Inc.]
Figure 2. This spray painting robot works quickly and
efficiently with nearly perfect quality. [Courtesy of
Kawasaki Robotics (USA), Inc.]
Figure 3. An assembly robot. [Courtesy of Kawasaki
Robotics (USA), Inc.]
Figure 1 illustrates the basic components that make up an industrial robot. These
components are the power supply, controller, teach pendant, axis control module,
input/output modules, and mechanical body. The main power supply to the robot is
AC run through a transformer. This main power supply provides voltage and current
to the robot's motor. The motor can be servo or non-servo. Servomotors, like the
one in Figure 2, are used for applications such as pick and place that require the robot
to move to a precise location.
In addition to the main power supply, there are separate power supplies to the robot
that can be located in a cabinet, shown in Figure 3, or in a power supply unit (PSU).
The PSU provides DC voltage to the robot's outputs and controller. Robots can be also
be powered by batteries, solar panels, springs, hydraulics, and pneumatics. However,
most industrial robots use a plug-in power supply.
In order to run its program and interface with inputs and outputs, a robot must have a
controller. The controller can be located in a cabinet that is external to the robot, or it
can be a microcontroller (MCU) inside the robot. A hand-held remote control called a
teach pendant is connected to the controller and is used to program the robot. Teach
pendants are connected to the controller by a cable.
The axis control module, which is also connected to the controller, allows the robot
to move through the coordinates specified by its program. The axis control module
also controls the speed at which the robot's body moves. Figure 1. An industrial robot is composed of a
power supply, controller, axis control module, and
mechanical body.
Figure 2. Servomotors are used for robotic
applications that require precise positioning.
Figure 3. A cabinet holding the controller and teach
pendant. [Courtesy of Kawasaki Robotics (USA),
Inc.]
A robot’s body consists of different mechanical parts that are typically made from some
type of metal or alloy such as steel, cast iron, or aluminum. For a robotic arm, the body
parts can include a base, shoulder, elbow, arm, wrist, and even fingers. Figure 1 shows a
basic robotic arm. Links and joints within the robotic arm allow the robot to move in
different directions.
An end-of-arm tool (EOAT), also known as the end-effector, is attached to the end
joint of the arm. End-effectors can be shaped like hands, like the one in Figure 2, or they
can be highly specialized tools, like the grinder in Figure 3. Hand-shaped effectors are
called grippers. Grippers come in many shapes and sizes. Tools also come in a wide
variety and are designed for specific tasks such as welding or grinding.
Effectors are activated in response to signals that the robot sends and receives through
an input/output module. Input signals from sensors on or near the robot provide
information about its surroundings. Output signals are then sent to the robotic arm to
activate the work tool. Figure 1. A robotic arm typically includes a base,
shoulder, arm, and end-effector.
Figure 2. A gripper is an end-effector that is
shaped like a hand.
Figure 3. This robot is using an end-of-arm tool
that is specifically for grinding.
There are two major classes of robots: fixed robotic arms and mobile robotic vehicles.
The robotic arm in Figure 1 is also known as a manipulator. A manipulator resembles
a human arm with a shoulder, elbow, wrist, and fingers. The manipulator is generally
mounted on a platform or suspended from a track while the arm reaches to various
distances and locations.
The joints on a robotic arm can move in different directions along particular axes. An
axis is an imaginary line or circle along which a robotic component can move. The axes
of a robotic joint can allow movement side-to-side, up and down, in and out, or in a
circle. Collectively these axes represent the robot's degrees of freedom.
Robotic arms have two basic types of joints. Prismatic joints, also known as linear
joints, slide in a straight line across one axis. A revolute joint, on the other hand,
gives a robotic arm a wide range of movement. Revolute joints rotate almost
exclusively around one axis like a shaft in a bearing. To make a single joint rotate
around more than one axis requires a ball-and-socket type of bearing and drive. This is
hard to build, has accuracy and wear issues, and is difficult to drive. The robot in
Figure 2 has two prismatic joints and one revolute joint.
Figure 1. A robotic arm is generally mounted on a
platform from which it reaches to various distances
and locations.
Figure 2. Prismatic joints slide in a straight line
across one axis while revolute joints rotate around
an axis.
In order to tell a robot where to move, an operator must be familiar with the
Cartesian coordinate system. The Cartesian coordinate system defines the
location of a single point in three-dimensional space using three axes. The X-axis,
Y-axis, and Z-axis join together like the corner of a box. The point where all the
axes meet is the origin. The X and Y axes are horizontal, with one axis going in
and out, and one axis going side-to-side. The Z axis goes up and down.
An effective way to picture the three Cartesian axes is by using the right-hand
rule. Place your hand on a table or a bench. Turn your right palm up, and then
extend only the thumb and forefinger. This forms an "L," with the middle finger up
to the ceiling, as shown in Figure 1. The thumb is the X-axis, the forefinger is the
Y-axis, and the elevated center finger is the Z-axis.
The positions of a robot are referenced according to different coordinate systems.
The coordinate systems vary depending on the point of origin. World coordinates
use the robot’s mounting base as a point of origin, as shown in Figure 2. Tool
coordinates use the tool at the end of the robot’s arm as the point of origin. Tool
coordinates are used for teaching the robot where to move. With tool coordinates,
the X, Y, and Z axes are set from the tool’s point of view. Figure 1. Using the right-hand rule, the thumb is the
X-axis, the forefinger is the Y-axis, and the elevated
center finger is the Z-axis
Figure 2. A robot can have different sets of
coordinates.
Robotic arms come in a variety of styles. Articulated robots, like the one illustrated
in Figure 1, most closely resemble a human arm. The arm of an articulated robot has
revolute joints, and the number of joints can vary. Articulated robots are very good
at picking up small objects.
A Cartesian robot, shown in Figure 2, has prismatic joints only. The linear
movement of the joints gives the Cartesian robot a highly rigid structure that allows
it to lift heavy objects. Cartesian robots are also extremely precise because of the
accuracy and arrangements of the prismatic bearings. Cartesian robots can move
through X, Y, and Z axes. The length of each axis can be adjusted depending on the
application. Cartesian robots are used for assembly and injection molding
applications.
Cylindrical robots have a combination of revolute and prismatic joints that allow
them to work well in round workspaces. Spherical robots, on the other hand, have a
joint configuration that allows the robot to move in a desired direction and then
extend to reach an object. Figure 3 shows a spherical robot. Spherical robots are
used for welding and material handling. A typical spherical robot has 4 to 6 revolute
joints.
SCARA robots are a type of cylindrical robot. SCARA stands for Selective Compliance
Arm for Robotic Assembly. The SCARA robot illustrated in Figure 4 has four axes of
movement. It can move through X, Y, Z coordinates and a fourth Theta Z
coordinate. Theta Z is a rotating axis that corresponds to the angle around the z-
axis of the tool at the end of the SCARA robot. SCARA robots are often used for
inserting electronic components into circuit boards. SCARA robots generally have
three parallel revolute joints and two parallel prismatic joints that are both in the Z
direction.
Figure 1. An articulated robot has revolute joints
only.
Figure 2. A Cartesian robot has prismatic joints
only.
Figure 3. This spherical robot can turn around on its
base and reach for an object.
Figure 4. SCARA robots can move through X, Y, Z
coordinates and a fourth Theta Z coordinate
corresponding to the end-effector.
The robotic arm is the most common type of industrial robot. However, there is a second
type of industrial robot known as the automatic guided vehicle (AGV). Unlike a robotic
arm, an AGV can move freely about the workspace. Instead of having a driver for
navigation, the AGV uses light reflectors, colored tape, or wires that are embedded in the
floor to guide it through a predetermined route.
There are four types of AGVs:
lTow vehicles, also known as tuggers (Figure 1), pull trailers loaded with material.
Tow vehicles are capable of pulling extremely heavy loads, some weighing up to
60,000 lbs. (27,215 kg). Tow vehicles do not load the materials; they simply
transport them.
lUnit load carriers (Figure 2) have powered decks that lift and lower to transport
pallets loaded with material.
lCart vehicles (Figure 3) are small, relatively inexpensive AGVs that can load material
like a unit load carrier or pull it like a tow vehicle. However, cart vehicles are usually
limited to loads of no more than 2,000 lbs. (907 kg).
lFork vehicles (Figure 4) lift and lower materials. Their load capacity can range from
1,200 to 5,000 lbs. (544 to 2,267 kg). Forks are available in different styles other
than the standard dual fork.
AGVs are extremely flexible in the distance and direction that they can move. You can find
AGVs in automotive, printing, chemical, medical and pharmaceutical, food and beverage,
distribution, paper, manufacturing, and warehousing applications.
Figure 1. A tow vehicle is capable of pulling
extremely heavy loads.
Figure 2. A unit load carrier has powered decks
that lift and lower.
Figure 3. A cart vehicle cannot pull loads
greater than 2,000 lbs. (907 kg).
Figure 4. Fork vehicles primarily lift and lower
materials.
In order to be considered a robot, a machine must have some form of artificial
intelligence. Artificial intelligence is simply a computer software program that contains
behavior rules, as shown in Figure 1. These rules tell the robot how to act as it learns
how to perform its job. For example, a robot could be programmed to move toward a
light source when light is detected by its photosensors. Or it could be programmed to
move away from any objects that come into contact with the robot’s feelers. Figure 2
shows how a robot learns to adjust its path after colliding with an object.
Like human intelligence, an artificial intelligence program controls different levels of
behavior. The lowest, most primitive level of artificial intelligence simply allows the robot
to move its mechanical parts. The next level controls the robot’s reflexes so it can
respond to its environment and make decisions based on the information detected by
its sensors. The highest level of artificial intelligence is devoted to the robot’s memory
and problem-solving abilities.
Figure 1. Artificial intelligence is simply a computer
software program. [Courtesy of Kawasaki Robotics
(USA), Inc.]
Figure 2. After colliding with an object, this robot
learns to adjust its path. (Courtesy of Kawasaki
Robotics (USA), Inc.)
Like a human worker, a robot must be trained to do its job correctly. While it is
possible for some robots to simply learn on their own by trial and error, most robots
are taught by humans. The three main methods for teaching robots are lead-through
programming, walk-through programming, and off-line programming.
In lead-through programming, shown in Figure 1, the robot is placed in "teach
mode" while the trainer uses a remote teach pendant to manipulate the robot through
the different steps of the job. This is the most common programming method. The
robot is moved manually via the teach pendant, which controls the robot axes.
In walk-through programming, shown in Figure 2, the trainer physically moves the
robot through different steps of the job process. The robot learns which positions it
must move through, and which functions it must perform. Because it involves physical
contact with the robot, walk-through programming is done inside the work envelope
of the robot. This is extremely hazardous. To ensure worker safety, the robot must
be placed in manual mode. In manual mode a robot cannot move unless the trainer
holds down a pushbutton.
Lead-through and walk-through teaching methods are considered online. They require
the robot to remain "on" in order to learn. Off-line programming, shown in Figure 3,
allows the trainer to work from a remote location. The trainer writes a program and
downloads it into the robot. From there, the program can be refined with lead-
through or walk-through programming.
Figure 1. In lead-through programming the trainer
uses a remote teach pendant to program the robot.
Figure 2. In walk-through programming the trainer
physically moves the robot through different steps
of the job process.
Figure 3. In offline programming a trainer writes a
program from a remote location and downloads it
into the robot.
Industrial robots can be extremely fast and strong. When robot accidents occur, they can
result in serious injury, loss of limb, and even the death of a worker. Never enter the
robot’s work envelope unless it is absolutely necessary. The work envelope or work
cell is the defined area of space through which a robot can move. A worker within the
robot’s work envelope can be struck by the robot or crushed between equipment, as
shown in Figure 1. Even if you are familiar with the work pattern of the robot, do not
assume that you can predict its movements. Changes to the robot’s program, program
errors, and equipment malfunctions can cause sudden, unpredictable movements by the
robot.
If you must be inside the robot’s work envelope for installation, programming, or
maintenance, use a lockout/tagout key like the one in Figure 2 to prevent the robot
from starting up. Always read the robot’s user manual and make sure you are familiar
with the manufacturer’s safety guidelines. In addition, always wear personal protective
equipment (PPE) such as a hard hat, safety glasses, and steel-toed boots.
Workers must be trained and supervised in the operation, maintenance, and emergency
procedures of the robot. Workers should learn and comply with the guidelines from the
Occupational Safety and Health Administration (OSHA), the National Institute for
Occupational Safety and Health (NIOSH), and the American National Standards
Institute (ANSI). Safety devices such as security gates, pressure mats, alarms, and
emergency stop circuitry should be installed near the robot as well. Figure 3 shows a
robot secured behind a safety fence.
Figure 1. Within a robot’s work envelope, a
worker is in danger of being struck or crushed.
Figure 2. Use a lockout/tagout key whenever
you are inside the robot’s work envelope.
Figure 3. Install safety devices near the robot to
protect workers. [Courtesy of Kawasaki Robotics
(USA), Inc.]
For the past several years, sales of industrial robots have risen steadily. It is likely
that the use of robots in industry will continue to increase. In addition to various
manufacturing industries, the military is also expected to increase its use of robots.
One of the most important developments in robot technology is the addition of vision
to the robot’s abilities. Sensors and cameras on the robot allow it to see its
environment, as shown in Figure 1. When coupled with the memory provided by a
computer, vision allows the robot to find specific objects and features to determine
their position. This allows the robot to pick randomly positioned and oriented
objects.
As continuing advancements are made in developing artificial intelligence, there will be
more opportunities for robots to assist people. New types of robots may be
developed for personal use. Figure 2 shows a robot that can perform the simple
household chore of vacuuming. Someday, having your own robot may be as common
as having a cellular phone.
Figure 1. The addition of vision sensors, such as
cameras, is an important development in robot
technology.
Figure 2. This Roomba vacuum cleaner runs without
an operator. (Courtesy of Larry D. Moore)
As the use of robots increases in manufacturing, there will also be an increased need for
robot technicians to maintain the robots. Robot technicians may be required by an
employer to earn at least a two-year degree in robotics, engineering, or computer science.
Some of the day-to-day tasks performed by a robot technician include:
lAssisting the robot engineer in designing end-of-arm tools and accessory equipment
for specific tasks.
lInspecting electronic components and other robot parts for defects.
lInstalling and testing the robot.
lInstalling safety systems for the robot.
lTraining robot operators, troubleshooting problems, and providing technical support.
lDisassembling the robot for service and repair.
The working conditions for a robot technician can vary. A technician may be required to
travel to different locations. He or she may work on the robot in a clean, quiet test lab, like
the one in Figure 1, or in a dirty, noisy factory. If there is a problem with the robot or there
is an installation deadline, the technician may be required to work overtime.
Figure 1. The working conditions for a robot
technician can vary.
Robots improve worker safety by relieving workers from dangerous and tedious
jobs, as shown in Figure 1. For example, robots relieve workers from handling harsh
chemicals or radioactive parts. They can also help to prevent repetitive motion
injuries by performing repetitive tasks.
The growth of robotics means that there will be a greater demand for workers who
can operate and maintain robots. Robots also provide economic advantages to
employers. Robots do not take sick days or vacation days, and they never get tired.
They can work 24 hours a day without stopping. In addition, robots can repeat a
task many times without varying the quality or consistency of the work. This reduces
waste, increases productivity, and improves product quality. Moreover expenses
associated with defective parts and workers compensation claims are eliminated
when robots do the work.
Despite the many benefits of using robots in the workplace, there are some
disadvantages to using robots. In past studies, the Bureau of Labor and Statistics
predicted that increased automation in the workplace could lead workers to feel
stressed, lonely, and like they lost of control of the process. Moreover, installing
robots to perform menial tasks does not always mean that human workers are
advanced to higher-functioning tasks. Sometimes workers are merely shifted to a
different low-skill task.
The cost of buying and installing a robot like the one in Figure 2 can be very high.
There is an initial investment in support technology for the robot, and the robot
itself can cost $200,000 or more. It takes time to program and troubleshoot a robot
after it has been installed. In addition, workers must be trained to operate and
maintain the robot.
Figure 1. This robot can stack containers on a pallet
all day without getting bored, tired, or injured.
[Courtesy of Kawasaki Robotics (USA), Inc.]
Figure 2. The initial cost of installing this plastic
molding robot may be very high. [Courtesy of
Kawasaki Robotics (USA), Inc.]
An industrial robot is a programmable mechanical device used in place of a person to
perform dangerous or repetitive tasks. Industrial robots were first used in the 1960s.
One of the most common industrial applications for robots today is welding.
The basic components of a robot are the power supply, controller, teach pendant, axis
control module, input/output modules, and mechanical body. A robot’s body consists of
a base, shoulder, elbow, arm, wrist, and an end-of-arm-tool. Robots use different
coordinate systems to determine where to move. The Cartesian coordinate system
defines the location of a single point in three-dimensional space using X, Y, and Z axes.
World coordinates have the robot’s mounting base as a point of origin. Tool
coordinates have the tool at the end of the robot’s arm as the point of origin.
Robotic arms come in different styles. Articulated robots closely resemble a human arm.
Cartesian robots have prismatic joints only. Cylindrical robots have a combination of
revolute and prismatic joints that allow them to work well in round workspaces.
Spherical robots have a joint configuration that allows the robot to move in a desired
direction and then extend to reach an object. SCARA robots can move through X, Y, Z
coordinates and a fourth Theta Z coordinate.
Automatic guided vehicles can move freely about the workspace. Tow vehicles pull
trailers loaded with material. Unit load carriers have powered decks that lift and lower to
transport pallets loaded with material. Cart vehicles can load material like a unit load
carrier or pull it like a tow vehicle. Fork vehicles lift and lower materials.
Artificial intelligence is a computer software program that contains behavior rules for
robots. Robots are trained to do their jobs through different programming methods. In
lead-through programming the trainer uses a teach pendant to program the robot. In
walk-through programming, the trainer physically moves the robot through the job
process. In off-line programming the trainer writes a program remotely and downloads
it into the robot.
Robot accidents can result in serious injury and even the death of a worker. Therefore,
workers must learn the proper operation, maintenance, and emergency procedures of
the robot.
Figure 1. An industrial robot is composed of a
power supply, controller, axis control module, and
mechanical body.
Figure 2. A robotic arm typically include a base,
shoulder, arm, and end-effector.
Figure 3. Robot accidents can result in serious
injury and even the death of a worker.
Term Definition
alloy A uniform mixture of two or more materials, one of which must be a metal. Industrial robots are usually
composed of alloys.
American National Standards
Institute An organization that oversees industry standards for commercial products and services. ANSI provides
guidelines for manufacturing, installing, and safeguarding robotic systems.
articulated robot A type of robotic arm that closely resembles a human arm. The arm of an articulated robot has revolute joints
and the number of joints can vary.
artificial intelligence A computer software program that contains behavior rules for robots. Artificial intelligence is one of the
characteristics that distinguishes robots from other programmable machines.
assembly The process of fitting components together into a larger or completed part.
automatic guided vehicle An industrial robot that can move freely about the workspace. AGVs can take the form of carts, forklifts, or
tow vehicles.
axes The plural of axis. An axis is an imaginary straight line or circle used to describe the location or movement of
an object in the Cartesian coordinate system.
axis control module A component that allows a robot to move in different directions. The axis control module also controls the
velocity and torque of the robotic arm.
cabinet An enclosure containing a robot's controller, axis control module, input/output module, and power supplies.
camera A device used to capture still images, such as photographs, or moving images, such as videos. Cameras give
a robot vision.
cart vehicle A small AGV that can load material like a unit load carrier or pull it like a tow vehicle. Cart vehicles are usually
limited to loads of no more than 2,000 lbs. (907 kg).
Cartesian coordinate system A numerical system that describes the location of an object by numerically expressing its distance from a
fixed position along three linear axes.
Cartesian robot A type of robotic arm that has prismatic joints only. The linear movement of the joints gives the Cartesian
robot a highly rigid structure that allows it to lift heavy objects.
clean room A room in which temperature, humidity, and air pressure are controlled and maintained at a specific level.
controller The main device that processes information and carries out instructions in a robot. Also known as the CPU, or
processor.
cylindrical robot A type of robotic arm that has a combination of revolute and prismatic joints. Cylindrical robots work well in
round workspaces.
degrees of freedom The available ways a component can move in three-dimensional space. Robots typically have 3 to 6 degrees of
freedom.
dross A type of scum formed by oxidation at the surface of molten metals.
end-effector The end component of a robotic arm that is shaped like a hand or like a specialized tool. Also known as end-
of-arm tool (EOAT).
end-of-arm tool The end component of a robotic arm that is shaped like a hand or like a specialized tool. Also known as an
end-effector.
feeler A sensor on a robot that responds to touch or pressure.
fork vehicle A type of AGV that can lift and lower materials. Forks are available in different styles other than the standard
dual fork.
gripper A hand-shaped end-effector designed for seizing and holding.
industrial robot A programmable mechanical device that is used in place of a person to perform dangerous or repetitive tasks
with a high degree of accuracy.
input/output module The jack where an input/output device is physically connected to a robot. Inputs and outputs allow the robot
to interact with its environment.
integrated circuit A miniaturized electronic circuit. The development of integrated circuits helped to improve the performance of
industrial robots.
intelligence The ability to learn, reason, and solve problems.
joint The location at which two or more parts of a robotic arm make contact. Joints allow parts to move in different
directions.
lead-through programming A programming method in which a robot is placed in "teach mode" while the trainer uses a remote teach
pendant to manipulate the robot through the different steps of the job. Lead-through programming is the
most common programming method.
linear joint A joint that moves in a straight line across one axis. Also known as a prismatic joint.
linear movement Movement in a straight line across one axis.
link A fastener that joins or connects the parts of a robotic arm.
lockout/tagout A method of protecting employees from accidental robot startup through proper locking and labeling of
robots that are undergoing maintenance.
machine loading The process of loading raw materials into machinery for processing.
main power supply The power supply that provides voltage and current to a robot’s motor. A robot's main power supply is AC
run through a transformer.
manipulator A robotic arm. A manipulator is generally mounted on a platform or suspended from a track while the arm
reaches to various distances and locations.
material removal The process of removing substances or matter from a surface. Material removal processes include cutting,
grinding, deburring, deflashing, polishing, waterjet cutting, and routering.
materials handling The process of loading, unloading, placing, or manipulating material. Types of material handling include
machine tending, part transfer, packaging, and palletizing.
microcontroller A tiny computer that is self-sufficient.
National Institute for
Occupational Safety and
Health
The federal agency responsible for conducting research and making recommendations for the prevention of
work-related injury and illness. Also known as NIOSH.
Occupational Safety and
Health Administration A government agency that helps employers reduce injuries, illnesses, and deaths in the workplace. Also
known as OSHA.
off-line programming A programming method in which a trainer writes a program from a remote location and downloads it into a
robot. Off-line programming can be refined with lead-through or walk-through programming.
origin The fixed, central point in the Cartesian coordinate system. The origin has a numerical value of zero.
packaging The process of assembling containers and components for shipping and storage.
palletizing The process of placing and securing containers or objects on pallets.
part transfer A type of material handling in which parts are transferred from one location to another.
personal protective
equipment Any of various safety equipment that workers wear or use to prevent injury in the workplace. Safety glasses
are common personal protective equipment (PPE).
pick and place The process of picking up an object or part in one location and placing it in another location.
power supply unit A separate power supply that provides DC voltage to a robot’s outputs and controller.
prismatic joint A joint that moves in a straight line across one axis. Also known as a linear joint.
revolute joint A joint that rotates around more than one axis.
right-hand rule A quick reference that shows the X-, Y-, and Z-axes. A person displays his or her right hand, and the first
three fingers from the right each represent the X-, Y-, and Z-axis in order.
robot technician A person who installs, services, troubleshoots, maintains, and repairs robots and automated production
systems.
robotic arm An arm-shaped robot generally mounted on a platform or suspended from a track while the arm reaches to
various distances and locations. Also known as a manipulator.
SCARA robot Selective Compliance Arm for Robotic Assembly. A type of cylindrical robot that has 4 axes of movement: X,
Y, Z, and Theta Z.
sensor A device that detects the presence or absence of an object, or certain properties of that object, and provides
feedback. Sensors allow robots to interact with their environment.
servomotor A type of motor used in applications that require precise positioning. Servomotors can move loads in excess
of 50 hp.
spherical robot A type of robotic arm that has a joint configuration that allows the robot to move in a desired direction and
then extend to reach an object. A typical spherical robot has 4 to 6 revolute joints.
spray painting Applying paint with a sprayer. Spray paint applications include painting, sealing, and coating.
stepper motor A type of motor that uses a permanent magnetic field to rotate. Stepper motors can rotate forward or
reverse, but they cannot move large loads.
teach pendant A hand-held device that can be used to program a robot and control its movements.
Theta Z coordinate A rotating axis that corresponds to the angle around the z-axis of the tool at the end of a SCARA robot.
tool coordinates A coordinate system that uses the tool at the end of the robot's arm as the point of origin.
tow vehicle A type of AGV that pulls trailers loaded with material. Tow vehicles are capable of pulling extremely heavy
loads.
transformer A device that transfers electrical energy from one circuit to another, without changing the frequency.
transistor A tiny electrical device that amplifies electrical signals and switches current on and off.
tugger Another name for a tow vehicle. Tuggers pull trailers loaded with material.
unit load carrier A type of AGV that has powered decks that lift and lower to transport pallets loaded with material.
unmanned aerial vehicle A robotic airplane that can fly without an onboard pilot.
walk-through programming A programming method in which the trainer physically moves the robot through different steps of the job
process.
welding A joining process that uses heat, pressure, and/or chemicals to fuse two materials together permanently.
Robots are used for welding in the automotive industry.
work cell The defined area of space through which a robot can move. Also known as the work envelope.
work envelope The defined area of space through which a robot can move. Also known as the work cell.
world coordinates A coordinate system that uses the robot’s mounting base as a point of origin.
X-axis The linear axis representing side-to-side movement in a robot.
Y-axis The linear axis representing back and forth movement in a robot.
Z-axis The linear axis that represents up and down movement in a robot.
Copyright © 2009 Tooling U, LLC. All Rights Reserved.
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Class Outline
Objectives
What Is a Robot?
The History of Robotics
The Industrial Applications of Robots
Basic Robot Components
The Parts of a Robot’s Body
Arm-Shaped Robots
Robot Coordinate Systems
Robotic Arm Configuration
Mobile Robots
Robots and Artificial Intelligence
Robot Teaching Methods
Robot Safety
Trends in Industrial Robotics
Careers in Robotics
The Pros and Cons of Robots
Summary
Lesson: 1/17
Objectives
Lesson: 2/17
What Is a Robot?
Lesson: 3/17
The History of Robotics
Lesson: 4/17
The Industrial Applications of Robots
Lesson: 5/17
Basic Robot Components
Lesson: 6/17
The Parts of a Robot’s Body
Lesson: 7/17
Arm-Shaped Robots
Lesson: 8/17
Robot Coordinate Systems
Lesson: 9/17
Robotic Arm Configuration
Lesson: 10/17
Mobile Robots
Lesson: 11/17
Robots and Artificial Intelligence
Lesson: 12/17
Robot Teaching Methods
Lesson: 13/17
Robot Safety
Lesson: 14/17
Trends in Industrial Robotics
Lesson: 15/17
Careers in Robotics
Lesson: 16/17
The Pros and Cons of Robots
Lesson: 17/17
Summary
Class Vocabulary
Intro to Robotics 110
lDefine a robot.
lDescribe the history of industrial robotics.
lDescribe the industrial applications of robots.
lDescribe the basic components of a robot.
lDescribe the different parts of a robot’s body.
lDescribe robotic arms.
lDescribe the coordinate systems used to program
a robot’s movement.
lDistinguish between different robotic arm
configurations.
lDescribe mobile robots.
lDescribe artificial intelligence for robots.
lDistinguish between different robot teaching
methods.
lDescribe safety precautions for working with
robots.
lDescribe present and future trends in industrial
robotics.
lDescribe careers in robotics.
lList the advantages and disadvantages of using
robots.
Figure 1. Robots can have different coordinates depending on the point of origin.
Figure 2. In lead-through programming, the trainer uses a remote teach pendant
to program the robot.
People have been fascinated by the idea of automated machines for centuries.
Devices propelled by water and steam were created as early as 350 B.C.E.
Throughout history scientists and inventors became increasingly interested in
creating machines that could duplicate human anatomy and movement. This
eventually gave rise to the modern industrial robot.
An industrial robot is a programmable mechanical device used in place of a person
to perform dangerous or repetitive tasks with a high degree of accuracy. Not all
programmable machines are robots, however. The laser welding machine in Figure 1
is a robot, but a programmable VCR is not. A robot must be able to move on its
own, sense information about its environment, and use that information to
accomplish a programmed task. Robots can change their behavior in response to
their environment while automated machines simply follow instructions.
Robots can be large or small and they come in many shapes. They are capable of
lifting very heavy objects and performing repetitive tasks for long periods of time
without stopping. Figure 2 shows a machine tending robot. In this class you will
learn the classifications, characteristics, and functions of industrial robots. You will
also learn basic safety precautions for working with robots.
Figure 1. This arc welding robot moves on its own and
uses a vision sensor to accomplish its task. [Courtesy
of Kawasaki Robotics (USA), Inc.]
Figure 2. This machine tending robot can work for
many hours without getting bored or tired. [Courtesy
of Kawasaki Robotics (USA), Inc.]
Industrial robots were first used in the 1960s. U.S. companies were looking for cheap
labor, and robotics was a potential solution. However, early robots were bulky, slow, and
inefficient. The amount of human effort required to keep the robots running cancelled out
any cost advantage that the robots provided. In the end, manufacturers realized that
robots could never fully replace people. Instead, robots simply became another part of
factory technology. The welding robots in Figure 1 are very good at their job, but they
do not have the flexibility and intelligence of a human worker.
The use of industrial robots increased significantly after stepper motors became smaller
and stronger and AC servomotors became more affordable. These developments, along
with the use of transistors and integrated circuits, improved the productivity of
robots.
Today’s robots are extremely smart and versatile. In the military, planes known as
unmanned aerial vehicles (UAVs) can fly without an onboard pilot. Robots are also
used for exploration. NASA makes extensive use of small robotic vehicles, like the rover
in Figure 2, to explore other planets.
Figure 1. Robots are an important part of factory
technology, but they will never fully replace
people.
Figure 2. NASA uses mobile robots like this Mars
rover to explore other planets.
In industry, robots perform a wide variety of tasks. They are often used to handle
materials that are extremely hot or heavy. For example, robots are used to remove
a waste product called dross from molten metal baths. A skimmer full of dross can
weigh up to 33 lbs (72.2 kg). In addition, metal baths can reach temperatures that
exceed 800°F (426°C). For a human, skimming dross would be a hot, exhausting,
and potentially dangerous job. But a robot can perform this work quickly and easily
without being harmed.
One of the most common industrial applications for robots is welding, shown in
Figure 1. Robots are ideal for welding because of their high speed, the uniform
quality of their work, and their ability to repeat tasks without wearing out. The
automotive industry is one of the largest users of robotic welders.
Spray painting, shown in Figure 2, is another common use for robots. The highly
repetitive motions required in spray painting are well-suited to robots. Robots can
paint quickly and efficiently with nearly perfect quality. Because of their speed and
efficiency, robots also use less paint.
The newspaper industry makes extensive use of robots for a type of materials
handling called palletizing. The robots load and unload stacks of newspapers onto
movable platforms called pallets. Other industrial uses for robots include
packaging, part transfer, pick and place, machine loading, material removal,
and assembly. An assembly robot is shown in Figure 3.
Robots are also an ideal resource for working with integrated circuits in a clean
room. ICs are extremely sensitive to dust and dirt and other types of debris.
Because robots have no skin, hair, or breath, they do not contaminate the clean
room environment.
Figure 1. Welding is a common industrial robot
application. [Courtesy of Kawasaki Robotics (USA),
Inc.]
Figure 2. This spray painting robot works quickly and
efficiently with nearly perfect quality. [Courtesy of
Kawasaki Robotics (USA), Inc.]
Figure 3. An assembly robot. [Courtesy of Kawasaki
Robotics (USA), Inc.]
Figure 1 illustrates the basic components that make up an industrial robot. These
components are the power supply, controller, teach pendant, axis control module,
input/output modules, and mechanical body. The main power supply to the robot is
AC run through a transformer. This main power supply provides voltage and current
to the robot's motor. The motor can be servo or non-servo. Servomotors, like the
one in Figure 2, are used for applications such as pick and place that require the robot
to move to a precise location.
In addition to the main power supply, there are separate power supplies to the robot
that can be located in a cabinet, shown in Figure 3, or in a power supply unit (PSU).
The PSU provides DC voltage to the robot's outputs and controller. Robots can be also
be powered by batteries, solar panels, springs, hydraulics, and pneumatics. However,
most industrial robots use a plug-in power supply.
In order to run its program and interface with inputs and outputs, a robot must have a
controller. The controller can be located in a cabinet that is external to the robot, or it
can be a microcontroller (MCU) inside the robot. A hand-held remote control called a
teach pendant is connected to the controller and is used to program the robot. Teach
pendants are connected to the controller by a cable.
The axis control module, which is also connected to the controller, allows the robot
to move through the coordinates specified by its program. The axis control module
also controls the speed at which the robot's body moves. Figure 1. An industrial robot is composed of a
power supply, controller, axis control module, and
mechanical body.
Figure 2. Servomotors are used for robotic
applications that require precise positioning.
Figure 3. A cabinet holding the controller and teach
pendant. [Courtesy of Kawasaki Robotics (USA),
Inc.]
A robot’s body consists of different mechanical parts that are typically made from some
type of metal or alloy such as steel, cast iron, or aluminum. For a robotic arm, the body
parts can include a base, shoulder, elbow, arm, wrist, and even fingers. Figure 1 shows a
basic robotic arm. Links and joints within the robotic arm allow the robot to move in
different directions.
An end-of-arm tool (EOAT), also known as the end-effector, is attached to the end
joint of the arm. End-effectors can be shaped like hands, like the one in Figure 2, or they
can be highly specialized tools, like the grinder in Figure 3. Hand-shaped effectors are
called grippers. Grippers come in many shapes and sizes. Tools also come in a wide
variety and are designed for specific tasks such as welding or grinding.
Effectors are activated in response to signals that the robot sends and receives through
an input/output module. Input signals from sensors on or near the robot provide
information about its surroundings. Output signals are then sent to the robotic arm to
activate the work tool. Figure 1. A robotic arm typically includes a base,
shoulder, arm, and end-effector.
Figure 2. A gripper is an end-effector that is
shaped like a hand.
Figure 3. This robot is using an end-of-arm tool
that is specifically for grinding.
There are two major classes of robots: fixed robotic arms and mobile robotic vehicles.
The robotic arm in Figure 1 is also known as a manipulator. A manipulator resembles
a human arm with a shoulder, elbow, wrist, and fingers. The manipulator is generally
mounted on a platform or suspended from a track while the arm reaches to various
distances and locations.
The joints on a robotic arm can move in different directions along particular axes. An
axis is an imaginary line or circle along which a robotic component can move. The axes
of a robotic joint can allow movement side-to-side, up and down, in and out, or in a
circle. Collectively these axes represent the robot's degrees of freedom.
Robotic arms have two basic types of joints. Prismatic joints, also known as linear
joints, slide in a straight line across one axis. A revolute joint, on the other hand,
gives a robotic arm a wide range of movement. Revolute joints rotate almost
exclusively around one axis like a shaft in a bearing. To make a single joint rotate
around more than one axis requires a ball-and-socket type of bearing and drive. This is
hard to build, has accuracy and wear issues, and is difficult to drive. The robot in
Figure 2 has two prismatic joints and one revolute joint.
Figure 1. A robotic arm is generally mounted on a
platform from which it reaches to various distances
and locations.
Figure 2. Prismatic joints slide in a straight line
across one axis while revolute joints rotate around
an axis.
In order to tell a robot where to move, an operator must be familiar with the
Cartesian coordinate system. The Cartesian coordinate system defines the
location of a single point in three-dimensional space using three axes. The X-axis,
Y-axis, and Z-axis join together like the corner of a box. The point where all the
axes meet is the origin. The X and Y axes are horizontal, with one axis going in
and out, and one axis going side-to-side. The Z axis goes up and down.
An effective way to picture the three Cartesian axes is by using the right-hand
rule. Place your hand on a table or a bench. Turn your right palm up, and then
extend only the thumb and forefinger. This forms an "L," with the middle finger up
to the ceiling, as shown in Figure 1. The thumb is the X-axis, the forefinger is the
Y-axis, and the elevated center finger is the Z-axis.
The positions of a robot are referenced according to different coordinate systems.
The coordinate systems vary depending on the point of origin. World coordinates
use the robot’s mounting base as a point of origin, as shown in Figure 2. Tool
coordinates use the tool at the end of the robot’s arm as the point of origin. Tool
coordinates are used for teaching the robot where to move. With tool coordinates,
the X, Y, and Z axes are set from the tool’s point of view. Figure 1. Using the right-hand rule, the thumb is the
X-axis, the forefinger is the Y-axis, and the elevated
center finger is the Z-axis
Figure 2. A robot can have different sets of
coordinates.
Robotic arms come in a variety of styles. Articulated robots, like the one illustrated
in Figure 1, most closely resemble a human arm. The arm of an articulated robot has
revolute joints, and the number of joints can vary. Articulated robots are very good
at picking up small objects.
A Cartesian robot, shown in Figure 2, has prismatic joints only. The linear
movement of the joints gives the Cartesian robot a highly rigid structure that allows
it to lift heavy objects. Cartesian robots are also extremely precise because of the
accuracy and arrangements of the prismatic bearings. Cartesian robots can move
through X, Y, and Z axes. The length of each axis can be adjusted depending on the
application. Cartesian robots are used for assembly and injection molding
applications.
Cylindrical robots have a combination of revolute and prismatic joints that allow
them to work well in round workspaces. Spherical robots, on the other hand, have a
joint configuration that allows the robot to move in a desired direction and then
extend to reach an object. Figure 3 shows a spherical robot. Spherical robots are
used for welding and material handling. A typical spherical robot has 4 to 6 revolute
joints.
SCARA robots are a type of cylindrical robot. SCARA stands for Selective Compliance
Arm for Robotic Assembly. The SCARA robot illustrated in Figure 4 has four axes of
movement. It can move through X, Y, Z coordinates and a fourth Theta Z
coordinate. Theta Z is a rotating axis that corresponds to the angle around the z-
axis of the tool at the end of the SCARA robot. SCARA robots are often used for
inserting electronic components into circuit boards. SCARA robots generally have
three parallel revolute joints and two parallel prismatic joints that are both in the Z
direction.
Figure 1. An articulated robot has revolute joints
only.
Figure 2. A Cartesian robot has prismatic joints
only.
Figure 3. This spherical robot can turn around on its
base and reach for an object.
Figure 4. SCARA robots can move through X, Y, Z
coordinates and a fourth Theta Z coordinate
corresponding to the end-effector.
The robotic arm is the most common type of industrial robot. However, there is a second
type of industrial robot known as the automatic guided vehicle (AGV). Unlike a robotic
arm, an AGV can move freely about the workspace. Instead of having a driver for
navigation, the AGV uses light reflectors, colored tape, or wires that are embedded in the
floor to guide it through a predetermined route.
There are four types of AGVs:
lTow vehicles, also known as tuggers (Figure 1), pull trailers loaded with material.
Tow vehicles are capable of pulling extremely heavy loads, some weighing up to
60,000 lbs. (27,215 kg). Tow vehicles do not load the materials; they simply
transport them.
lUnit load carriers (Figure 2) have powered decks that lift and lower to transport
pallets loaded with material.
lCart vehicles (Figure 3) are small, relatively inexpensive AGVs that can load material
like a unit load carrier or pull it like a tow vehicle. However, cart vehicles are usually
limited to loads of no more than 2,000 lbs. (907 kg).
lFork vehicles (Figure 4) lift and lower materials. Their load capacity can range from
1,200 to 5,000 lbs. (544 to 2,267 kg). Forks are available in different styles other
than the standard dual fork.
AGVs are extremely flexible in the distance and direction that they can move. You can find
AGVs in automotive, printing, chemical, medical and pharmaceutical, food and beverage,
distribution, paper, manufacturing, and warehousing applications.
Figure 1. A tow vehicle is capable of pulling
extremely heavy loads.
Figure 2. A unit load carrier has powered decks
that lift and lower.
Figure 3. A cart vehicle cannot pull loads
greater than 2,000 lbs. (907 kg).
Figure 4. Fork vehicles primarily lift and lower
materials.
In order to be considered a robot, a machine must have some form of artificial
intelligence. Artificial intelligence is simply a computer software program that contains
behavior rules, as shown in Figure 1. These rules tell the robot how to act as it learns
how to perform its job. For example, a robot could be programmed to move toward a
light source when light is detected by its photosensors. Or it could be programmed to
move away from any objects that come into contact with the robot’s feelers. Figure 2
shows how a robot learns to adjust its path after colliding with an object.
Like human intelligence, an artificial intelligence program controls different levels of
behavior. The lowest, most primitive level of artificial intelligence simply allows the robot
to move its mechanical parts. The next level controls the robot’s reflexes so it can
respond to its environment and make decisions based on the information detected by
its sensors. The highest level of artificial intelligence is devoted to the robot’s memory
and problem-solving abilities.
Figure 1. Artificial intelligence is simply a computer
software program. [Courtesy of Kawasaki Robotics
(USA), Inc.]
Figure 2. After colliding with an object, this robot
learns to adjust its path. (Courtesy of Kawasaki
Robotics (USA), Inc.)
Like a human worker, a robot must be trained to do its job correctly. While it is
possible for some robots to simply learn on their own by trial and error, most robots
are taught by humans. The three main methods for teaching robots are lead-through
programming, walk-through programming, and off-line programming.
In lead-through programming, shown in Figure 1, the robot is placed in "teach
mode" while the trainer uses a remote teach pendant to manipulate the robot through
the different steps of the job. This is the most common programming method. The
robot is moved manually via the teach pendant, which controls the robot axes.
In walk-through programming, shown in Figure 2, the trainer physically moves the
robot through different steps of the job process. The robot learns which positions it
must move through, and which functions it must perform. Because it involves physical
contact with the robot, walk-through programming is done inside the work envelope
of the robot. This is extremely hazardous. To ensure worker safety, the robot must
be placed in manual mode. In manual mode a robot cannot move unless the trainer
holds down a pushbutton.
Lead-through and walk-through teaching methods are considered online. They require
the robot to remain "on" in order to learn. Off-line programming, shown in Figure 3,
allows the trainer to work from a remote location. The trainer writes a program and
downloads it into the robot. From there, the program can be refined with lead-
through or walk-through programming.
Figure 1. In lead-through programming the trainer
uses a remote teach pendant to program the robot.
Figure 2. In walk-through programming the trainer
physically moves the robot through different steps
of the job process.
Figure 3. In offline programming a trainer writes a
program from a remote location and downloads it
into the robot.
Industrial robots can be extremely fast and strong. When robot accidents occur, they can
result in serious injury, loss of limb, and even the death of a worker. Never enter the
robot’s work envelope unless it is absolutely necessary. The work envelope or work
cell is the defined area of space through which a robot can move. A worker within the
robot’s work envelope can be struck by the robot or crushed between equipment, as
shown in Figure 1. Even if you are familiar with the work pattern of the robot, do not
assume that you can predict its movements. Changes to the robot’s program, program
errors, and equipment malfunctions can cause sudden, unpredictable movements by the
robot.
If you must be inside the robot’s work envelope for installation, programming, or
maintenance, use a lockout/tagout key like the one in Figure 2 to prevent the robot
from starting up. Always read the robot’s user manual and make sure you are familiar
with the manufacturer’s safety guidelines. In addition, always wear personal protective
equipment (PPE) such as a hard hat, safety glasses, and steel-toed boots.
Workers must be trained and supervised in the operation, maintenance, and emergency
procedures of the robot. Workers should learn and comply with the guidelines from the
Occupational Safety and Health Administration (OSHA), the National Institute for
Occupational Safety and Health (NIOSH), and the American National Standards
Institute (ANSI). Safety devices such as security gates, pressure mats, alarms, and
emergency stop circuitry should be installed near the robot as well. Figure 3 shows a
robot secured behind a safety fence.
Figure 1. Within a robot’s work envelope, a
worker is in danger of being struck or crushed.
Figure 2. Use a lockout/tagout key whenever
you are inside the robot’s work envelope.
Figure 3. Install safety devices near the robot to
protect workers. [Courtesy of Kawasaki Robotics
(USA), Inc.]
For the past several years, sales of industrial robots have risen steadily. It is likely
that the use of robots in industry will continue to increase. In addition to various
manufacturing industries, the military is also expected to increase its use of robots.
One of the most important developments in robot technology is the addition of vision
to the robot’s abilities. Sensors and cameras on the robot allow it to see its
environment, as shown in Figure 1. When coupled with the memory provided by a
computer, vision allows the robot to find specific objects and features to determine
their position. This allows the robot to pick randomly positioned and oriented
objects.
As continuing advancements are made in developing artificial intelligence, there will be
more opportunities for robots to assist people. New types of robots may be
developed for personal use. Figure 2 shows a robot that can perform the simple
household chore of vacuuming. Someday, having your own robot may be as common
as having a cellular phone.
Figure 1. The addition of vision sensors, such as
cameras, is an important development in robot
technology.
Figure 2. This Roomba vacuum cleaner runs without
an operator. (Courtesy of Larry D. Moore)
As the use of robots increases in manufacturing, there will also be an increased need for
robot technicians to maintain the robots. Robot technicians may be required by an
employer to earn at least a two-year degree in robotics, engineering, or computer science.
Some of the day-to-day tasks performed by a robot technician include:
lAssisting the robot engineer in designing end-of-arm tools and accessory equipment
for specific tasks.
lInspecting electronic components and other robot parts for defects.
lInstalling and testing the robot.
lInstalling safety systems for the robot.
lTraining robot operators, troubleshooting problems, and providing technical support.
lDisassembling the robot for service and repair.
The working conditions for a robot technician can vary. A technician may be required to
travel to different locations. He or she may work on the robot in a clean, quiet test lab, like
the one in Figure 1, or in a dirty, noisy factory. If there is a problem with the robot or there
is an installation deadline, the technician may be required to work overtime.
Figure 1. The working conditions for a robot
technician can vary.
Robots improve worker safety by relieving workers from dangerous and tedious
jobs, as shown in Figure 1. For example, robots relieve workers from handling harsh
chemicals or radioactive parts. They can also help to prevent repetitive motion
injuries by performing repetitive tasks.
The growth of robotics means that there will be a greater demand for workers who
can operate and maintain robots. Robots also provide economic advantages to
employers. Robots do not take sick days or vacation days, and they never get tired.
They can work 24 hours a day without stopping. In addition, robots can repeat a
task many times without varying the quality or consistency of the work. This reduces
waste, increases productivity, and improves product quality. Moreover expenses
associated with defective parts and workers compensation claims are eliminated
when robots do the work.
Despite the many benefits of using robots in the workplace, there are some
disadvantages to using robots. In past studies, the Bureau of Labor and Statistics
predicted that increased automation in the workplace could lead workers to feel
stressed, lonely, and like they lost of control of the process. Moreover, installing
robots to perform menial tasks does not always mean that human workers are
advanced to higher-functioning tasks. Sometimes workers are merely shifted to a
different low-skill task.
The cost of buying and installing a robot like the one in Figure 2 can be very high.
There is an initial investment in support technology for the robot, and the robot
itself can cost $200,000 or more. It takes time to program and troubleshoot a robot
after it has been installed. In addition, workers must be trained to operate and
maintain the robot.
Figure 1. This robot can stack containers on a pallet
all day without getting bored, tired, or injured.
[Courtesy of Kawasaki Robotics (USA), Inc.]
Figure 2. The initial cost of installing this plastic
molding robot may be very high. [Courtesy of
Kawasaki Robotics (USA), Inc.]
An industrial robot is a programmable mechanical device used in place of a person to
perform dangerous or repetitive tasks. Industrial robots were first used in the 1960s.
One of the most common industrial applications for robots today is welding.
The basic components of a robot are the power supply, controller, teach pendant, axis
control module, input/output modules, and mechanical body. A robot’s body consists of
a base, shoulder, elbow, arm, wrist, and an end-of-arm-tool. Robots use different
coordinate systems to determine where to move. The Cartesian coordinate system
defines the location of a single point in three-dimensional space using X, Y, and Z axes.
World coordinates have the robot’s mounting base as a point of origin. Tool
coordinates have the tool at the end of the robot’s arm as the point of origin.
Robotic arms come in different styles. Articulated robots closely resemble a human arm.
Cartesian robots have prismatic joints only. Cylindrical robots have a combination of
revolute and prismatic joints that allow them to work well in round workspaces.
Spherical robots have a joint configuration that allows the robot to move in a desired
direction and then extend to reach an object. SCARA robots can move through X, Y, Z
coordinates and a fourth Theta Z coordinate.
Automatic guided vehicles can move freely about the workspace. Tow vehicles pull
trailers loaded with material. Unit load carriers have powered decks that lift and lower to
transport pallets loaded with material. Cart vehicles can load material like a unit load
carrier or pull it like a tow vehicle. Fork vehicles lift and lower materials.
Artificial intelligence is a computer software program that contains behavior rules for
robots. Robots are trained to do their jobs through different programming methods. In
lead-through programming the trainer uses a teach pendant to program the robot. In
walk-through programming, the trainer physically moves the robot through the job
process. In off-line programming the trainer writes a program remotely and downloads
it into the robot.
Robot accidents can result in serious injury and even the death of a worker. Therefore,
workers must learn the proper operation, maintenance, and emergency procedures of
the robot.
Figure 1. An industrial robot is composed of a
power supply, controller, axis control module, and
mechanical body.
Figure 2. A robotic arm typically include a base,
shoulder, arm, and end-effector.
Figure 3. Robot accidents can result in serious
injury and even the death of a worker.
Term Definition
alloy A uniform mixture of two or more materials, one of which must be a metal. Industrial robots are usually
composed of alloys.
American National Standards
Institute An organization that oversees industry standards for commercial products and services. ANSI provides
guidelines for manufacturing, installing, and safeguarding robotic systems.
articulated robot A type of robotic arm that closely resembles a human arm. The arm of an articulated robot has revolute joints
and the number of joints can vary.
artificial intelligence A computer software program that contains behavior rules for robots. Artificial intelligence is one of the
characteristics that distinguishes robots from other programmable machines.
assembly The process of fitting components together into a larger or completed part.
automatic guided vehicle An industrial robot that can move freely about the workspace. AGVs can take the form of carts, forklifts, or
tow vehicles.
axes The plural of axis. An axis is an imaginary straight line or circle used to describe the location or movement of
an object in the Cartesian coordinate system.
axis control module A component that allows a robot to move in different directions. The axis control module also controls the
velocity and torque of the robotic arm.
cabinet An enclosure containing a robot's controller, axis control module, input/output module, and power supplies.
camera A device used to capture still images, such as photographs, or moving images, such as videos. Cameras give
a robot vision.
cart vehicle A small AGV that can load material like a unit load carrier or pull it like a tow vehicle. Cart vehicles are usually
limited to loads of no more than 2,000 lbs. (907 kg).
Cartesian coordinate system A numerical system that describes the location of an object by numerically expressing its distance from a
fixed position along three linear axes.
Cartesian robot A type of robotic arm that has prismatic joints only. The linear movement of the joints gives the Cartesian
robot a highly rigid structure that allows it to lift heavy objects.
clean room A room in which temperature, humidity, and air pressure are controlled and maintained at a specific level.
controller The main device that processes information and carries out instructions in a robot. Also known as the CPU, or
processor.
cylindrical robot A type of robotic arm that has a combination of revolute and prismatic joints. Cylindrical robots work well in
round workspaces.
degrees of freedom The available ways a component can move in three-dimensional space. Robots typically have 3 to 6 degrees of
freedom.
dross A type of scum formed by oxidation at the surface of molten metals.
end-effector The end component of a robotic arm that is shaped like a hand or like a specialized tool. Also known as end-
of-arm tool (EOAT).
end-of-arm tool The end component of a robotic arm that is shaped like a hand or like a specialized tool. Also known as an
end-effector.
feeler A sensor on a robot that responds to touch or pressure.
fork vehicle A type of AGV that can lift and lower materials. Forks are available in different styles other than the standard
dual fork.
gripper A hand-shaped end-effector designed for seizing and holding.
industrial robot A programmable mechanical device that is used in place of a person to perform dangerous or repetitive tasks
with a high degree of accuracy.
input/output module The jack where an input/output device is physically connected to a robot. Inputs and outputs allow the robot
to interact with its environment.
integrated circuit A miniaturized electronic circuit. The development of integrated circuits helped to improve the performance of
industrial robots.
intelligence The ability to learn, reason, and solve problems.
joint The location at which two or more parts of a robotic arm make contact. Joints allow parts to move in different
directions.
lead-through programming A programming method in which a robot is placed in "teach mode" while the trainer uses a remote teach
pendant to manipulate the robot through the different steps of the job. Lead-through programming is the
most common programming method.
linear joint A joint that moves in a straight line across one axis. Also known as a prismatic joint.
linear movement Movement in a straight line across one axis.
link A fastener that joins or connects the parts of a robotic arm.
lockout/tagout A method of protecting employees from accidental robot startup through proper locking and labeling of
robots that are undergoing maintenance.
machine loading The process of loading raw materials into machinery for processing.
main power supply The power supply that provides voltage and current to a robot’s motor. A robot's main power supply is AC
run through a transformer.
manipulator A robotic arm. A manipulator is generally mounted on a platform or suspended from a track while the arm
reaches to various distances and locations.
material removal The process of removing substances or matter from a surface. Material removal processes include cutting,
grinding, deburring, deflashing, polishing, waterjet cutting, and routering.
materials handling The process of loading, unloading, placing, or manipulating material. Types of material handling include
machine tending, part transfer, packaging, and palletizing.
microcontroller A tiny computer that is self-sufficient.
National Institute for
Occupational Safety and
Health
The federal agency responsible for conducting research and making recommendations for the prevention of
work-related injury and illness. Also known as NIOSH.
Occupational Safety and
Health Administration A government agency that helps employers reduce injuries, illnesses, and deaths in the workplace. Also
known as OSHA.
off-line programming A programming method in which a trainer writes a program from a remote location and downloads it into a
robot. Off-line programming can be refined with lead-through or walk-through programming.
origin The fixed, central point in the Cartesian coordinate system. The origin has a numerical value of zero.
packaging The process of assembling containers and components for shipping and storage.
palletizing The process of placing and securing containers or objects on pallets.
part transfer A type of material handling in which parts are transferred from one location to another.
personal protective
equipment Any of various safety equipment that workers wear or use to prevent injury in the workplace. Safety glasses
are common personal protective equipment (PPE).
pick and place The process of picking up an object or part in one location and placing it in another location.
power supply unit A separate power supply that provides DC voltage to a robot’s outputs and controller.
prismatic joint A joint that moves in a straight line across one axis. Also known as a linear joint.
revolute joint A joint that rotates around more than one axis.
right-hand rule A quick reference that shows the X-, Y-, and Z-axes. A person displays his or her right hand, and the first
three fingers from the right each represent the X-, Y-, and Z-axis in order.
robot technician A person who installs, services, troubleshoots, maintains, and repairs robots and automated production
systems.
robotic arm An arm-shaped robot generally mounted on a platform or suspended from a track while the arm reaches to
various distances and locations. Also known as a manipulator.
SCARA robot Selective Compliance Arm for Robotic Assembly. A type of cylindrical robot that has 4 axes of movement: X,
Y, Z, and Theta Z.
sensor A device that detects the presence or absence of an object, or certain properties of that object, and provides
feedback. Sensors allow robots to interact with their environment.
servomotor A type of motor used in applications that require precise positioning. Servomotors can move loads in excess
of 50 hp.
spherical robot A type of robotic arm that has a joint configuration that allows the robot to move in a desired direction and
then extend to reach an object. A typical spherical robot has 4 to 6 revolute joints.
spray painting Applying paint with a sprayer. Spray paint applications include painting, sealing, and coating.
stepper motor A type of motor that uses a permanent magnetic field to rotate. Stepper motors can rotate forward or
reverse, but they cannot move large loads.
teach pendant A hand-held device that can be used to program a robot and control its movements.
Theta Z coordinate A rotating axis that corresponds to the angle around the z-axis of the tool at the end of a SCARA robot.
tool coordinates A coordinate system that uses the tool at the end of the robot's arm as the point of origin.
tow vehicle A type of AGV that pulls trailers loaded with material. Tow vehicles are capable of pulling extremely heavy
loads.
transformer A device that transfers electrical energy from one circuit to another, without changing the frequency.
transistor A tiny electrical device that amplifies electrical signals and switches current on and off.
tugger Another name for a tow vehicle. Tuggers pull trailers loaded with material.
unit load carrier A type of AGV that has powered decks that lift and lower to transport pallets loaded with material.
unmanned aerial vehicle A robotic airplane that can fly without an onboard pilot.
walk-through programming A programming method in which the trainer physically moves the robot through different steps of the job
process.
welding A joining process that uses heat, pressure, and/or chemicals to fuse two materials together permanently.
Robots are used for welding in the automotive industry.
work cell The defined area of space through which a robot can move. Also known as the work envelope.
work envelope The defined area of space through which a robot can move. Also known as the work cell.
world coordinates A coordinate system that uses the robot’s mounting base as a point of origin.
X-axis The linear axis representing side-to-side movement in a robot.
Y-axis The linear axis representing back and forth movement in a robot.
Z-axis The linear axis that represents up and down movement in a robot.
Copyright © 2009 Tooling U, LLC. All Rights Reserved.
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Class Outline
Objectives
What Is a Robot?
The History of Robotics
The Industrial Applications of Robots
Basic Robot Components
The Parts of a Robot’s Body
Arm-Shaped Robots
Robot Coordinate Systems
Robotic Arm Configuration
Mobile Robots
Robots and Artificial Intelligence
Robot Teaching Methods
Robot Safety
Trends in Industrial Robotics
Careers in Robotics
The Pros and Cons of Robots
Summary
Lesson: 1/17
Objectives
Lesson: 2/17
What Is a Robot?
Lesson: 3/17
The History of Robotics
Lesson: 4/17
The Industrial Applications of Robots
Lesson: 5/17
Basic Robot Components
Lesson: 6/17
The Parts of a Robot’s Body
Lesson: 7/17
Arm-Shaped Robots
Lesson: 8/17
Robot Coordinate Systems
Lesson: 9/17
Robotic Arm Configuration
Lesson: 10/17
Mobile Robots
Lesson: 11/17
Robots and Artificial Intelligence
Lesson: 12/17
Robot Teaching Methods
Lesson: 13/17
Robot Safety
Lesson: 14/17
Trends in Industrial Robotics
Lesson: 15/17
Careers in Robotics
Lesson: 16/17
The Pros and Cons of Robots
Lesson: 17/17
Summary
Class Vocabulary
Intro to Robotics 110
lDefine a robot.
lDescribe the history of industrial robotics.
lDescribe the industrial applications of robots.
lDescribe the basic components of a robot.
lDescribe the different parts of a robot’s body.
lDescribe robotic arms.
lDescribe the coordinate systems used to program
a robot’s movement.
lDistinguish between different robotic arm
configurations.
lDescribe mobile robots.
lDescribe artificial intelligence for robots.
lDistinguish between different robot teaching
methods.
lDescribe safety precautions for working with
robots.
lDescribe present and future trends in industrial
robotics.
lDescribe careers in robotics.
lList the advantages and disadvantages of using
robots.
Figure 1. Robots can have different coordinates depending on the point of origin.
Figure 2. In lead-through programming, the trainer uses a remote teach pendant
to program the robot.
People have been fascinated by the idea of automated machines for centuries.
Devices propelled by water and steam were created as early as 350 B.C.E.
Throughout history scientists and inventors became increasingly interested in
creating machines that could duplicate human anatomy and movement. This
eventually gave rise to the modern industrial robot.
An industrial robot is a programmable mechanical device used in place of a person
to perform dangerous or repetitive tasks with a high degree of accuracy. Not all
programmable machines are robots, however. The laser welding machine in Figure 1
is a robot, but a programmable VCR is not. A robot must be able to move on its
own, sense information about its environment, and use that information to
accomplish a programmed task. Robots can change their behavior in response to
their environment while automated machines simply follow instructions.
Robots can be large or small and they come in many shapes. They are capable of
lifting very heavy objects and performing repetitive tasks for long periods of time
without stopping. Figure 2 shows a machine tending robot. In this class you will
learn the classifications, characteristics, and functions of industrial robots. You will
also learn basic safety precautions for working with robots.
Figure 1. This arc welding robot moves on its own and
uses a vision sensor to accomplish its task. [Courtesy
of Kawasaki Robotics (USA), Inc.]
Figure 2. This machine tending robot can work for
many hours without getting bored or tired. [Courtesy
of Kawasaki Robotics (USA), Inc.]
Industrial robots were first used in the 1960s. U.S. companies were looking for cheap
labor, and robotics was a potential solution. However, early robots were bulky, slow, and
inefficient. The amount of human effort required to keep the robots running cancelled out
any cost advantage that the robots provided. In the end, manufacturers realized that
robots could never fully replace people. Instead, robots simply became another part of
factory technology. The welding robots in Figure 1 are very good at their job, but they
do not have the flexibility and intelligence of a human worker.
The use of industrial robots increased significantly after stepper motors became smaller
and stronger and AC servomotors became more affordable. These developments, along
with the use of transistors and integrated circuits, improved the productivity of
robots.
Today’s robots are extremely smart and versatile. In the military, planes known as
unmanned aerial vehicles (UAVs) can fly without an onboard pilot. Robots are also
used for exploration. NASA makes extensive use of small robotic vehicles, like the rover
in Figure 2, to explore other planets.
Figure 1. Robots are an important part of factory
technology, but they will never fully replace
people.
Figure 2. NASA uses mobile robots like this Mars
rover to explore other planets.
In industry, robots perform a wide variety of tasks. They are often used to handle
materials that are extremely hot or heavy. For example, robots are used to remove
a waste product called dross from molten metal baths. A skimmer full of dross can
weigh up to 33 lbs (72.2 kg). In addition, metal baths can reach temperatures that
exceed 800°F (426°C). For a human, skimming dross would be a hot, exhausting,
and potentially dangerous job. But a robot can perform this work quickly and easily
without being harmed.
One of the most common industrial applications for robots is welding, shown in
Figure 1. Robots are ideal for welding because of their high speed, the uniform
quality of their work, and their ability to repeat tasks without wearing out. The
automotive industry is one of the largest users of robotic welders.
Spray painting, shown in Figure 2, is another common use for robots. The highly
repetitive motions required in spray painting are well-suited to robots. Robots can
paint quickly and efficiently with nearly perfect quality. Because of their speed and
efficiency, robots also use less paint.
The newspaper industry makes extensive use of robots for a type of materials
handling called palletizing. The robots load and unload stacks of newspapers onto
movable platforms called pallets. Other industrial uses for robots include
packaging, part transfer, pick and place, machine loading, material removal,
and assembly. An assembly robot is shown in Figure 3.
Robots are also an ideal resource for working with integrated circuits in a clean
room. ICs are extremely sensitive to dust and dirt and other types of debris.
Because robots have no skin, hair, or breath, they do not contaminate the clean
room environment.
Figure 1. Welding is a common industrial robot
application. [Courtesy of Kawasaki Robotics (USA),
Inc.]
Figure 2. This spray painting robot works quickly and
efficiently with nearly perfect quality. [Courtesy of
Kawasaki Robotics (USA), Inc.]
Figure 3. An assembly robot. [Courtesy of Kawasaki
Robotics (USA), Inc.]
Figure 1 illustrates the basic components that make up an industrial robot. These
components are the power supply, controller, teach pendant, axis control module,
input/output modules, and mechanical body. The main power supply to the robot is
AC run through a transformer. This main power supply provides voltage and current
to the robot's motor. The motor can be servo or non-servo. Servomotors, like the
one in Figure 2, are used for applications such as pick and place that require the robot
to move to a precise location.
In addition to the main power supply, there are separate power supplies to the robot
that can be located in a cabinet, shown in Figure 3, or in a power supply unit (PSU).
The PSU provides DC voltage to the robot's outputs and controller. Robots can be also
be powered by batteries, solar panels, springs, hydraulics, and pneumatics. However,
most industrial robots use a plug-in power supply.
In order to run its program and interface with inputs and outputs, a robot must have a
controller. The controller can be located in a cabinet that is external to the robot, or it
can be a microcontroller (MCU) inside the robot. A hand-held remote control called a
teach pendant is connected to the controller and is used to program the robot. Teach
pendants are connected to the controller by a cable.
The axis control module, which is also connected to the controller, allows the robot
to move through the coordinates specified by its program. The axis control module
also controls the speed at which the robot's body moves. Figure 1. An industrial robot is composed of a
power supply, controller, axis control module, and
mechanical body.
Figure 2. Servomotors are used for robotic
applications that require precise positioning.
Figure 3. A cabinet holding the controller and teach
pendant. [Courtesy of Kawasaki Robotics (USA),
Inc.]
A robot’s body consists of different mechanical parts that are typically made from some
type of metal or alloy such as steel, cast iron, or aluminum. For a robotic arm, the body
parts can include a base, shoulder, elbow, arm, wrist, and even fingers. Figure 1 shows a
basic robotic arm. Links and joints within the robotic arm allow the robot to move in
different directions.
An end-of-arm tool (EOAT), also known as the end-effector, is attached to the end
joint of the arm. End-effectors can be shaped like hands, like the one in Figure 2, or they
can be highly specialized tools, like the grinder in Figure 3. Hand-shaped effectors are
called grippers. Grippers come in many shapes and sizes. Tools also come in a wide
variety and are designed for specific tasks such as welding or grinding.
Effectors are activated in response to signals that the robot sends and receives through
an input/output module. Input signals from sensors on or near the robot provide
information about its surroundings. Output signals are then sent to the robotic arm to
activate the work tool. Figure 1. A robotic arm typically includes a base,
shoulder, arm, and end-effector.
Figure 2. A gripper is an end-effector that is
shaped like a hand.
Figure 3. This robot is using an end-of-arm tool
that is specifically for grinding.
There are two major classes of robots: fixed robotic arms and mobile robotic vehicles.
The robotic arm in Figure 1 is also known as a manipulator. A manipulator resembles
a human arm with a shoulder, elbow, wrist, and fingers. The manipulator is generally
mounted on a platform or suspended from a track while the arm reaches to various
distances and locations.
The joints on a robotic arm can move in different directions along particular axes. An
axis is an imaginary line or circle along which a robotic component can move. The axes
of a robotic joint can allow movement side-to-side, up and down, in and out, or in a
circle. Collectively these axes represent the robot's degrees of freedom.
Robotic arms have two basic types of joints. Prismatic joints, also known as linear
joints, slide in a straight line across one axis. A revolute joint, on the other hand,
gives a robotic arm a wide range of movement. Revolute joints rotate almost
exclusively around one axis like a shaft in a bearing. To make a single joint rotate
around more than one axis requires a ball-and-socket type of bearing and drive. This is
hard to build, has accuracy and wear issues, and is difficult to drive. The robot in
Figure 2 has two prismatic joints and one revolute joint.
Figure 1. A robotic arm is generally mounted on a
platform from which it reaches to various distances
and locations.
Figure 2. Prismatic joints slide in a straight line
across one axis while revolute joints rotate around
an axis.
In order to tell a robot where to move, an operator must be familiar with the
Cartesian coordinate system. The Cartesian coordinate system defines the
location of a single point in three-dimensional space using three axes. The X-axis,
Y-axis, and Z-axis join together like the corner of a box. The point where all the
axes meet is the origin. The X and Y axes are horizontal, with one axis going in
and out, and one axis going side-to-side. The Z axis goes up and down.
An effective way to picture the three Cartesian axes is by using the right-hand
rule. Place your hand on a table or a bench. Turn your right palm up, and then
extend only the thumb and forefinger. This forms an "L," with the middle finger up
to the ceiling, as shown in Figure 1. The thumb is the X-axis, the forefinger is the
Y-axis, and the elevated center finger is the Z-axis.
The positions of a robot are referenced according to different coordinate systems.
The coordinate systems vary depending on the point of origin. World coordinates
use the robot’s mounting base as a point of origin, as shown in Figure 2. Tool
coordinates use the tool at the end of the robot’s arm as the point of origin. Tool
coordinates are used for teaching the robot where to move. With tool coordinates,
the X, Y, and Z axes are set from the tool’s point of view. Figure 1. Using the right-hand rule, the thumb is the
X-axis, the forefinger is the Y-axis, and the elevated
center finger is the Z-axis
Figure 2. A robot can have different sets of
coordinates.
Robotic arms come in a variety of styles. Articulated robots, like the one illustrated
in Figure 1, most closely resemble a human arm. The arm of an articulated robot has
revolute joints, and the number of joints can vary. Articulated robots are very good
at picking up small objects.
A Cartesian robot, shown in Figure 2, has prismatic joints only. The linear
movement of the joints gives the Cartesian robot a highly rigid structure that allows
it to lift heavy objects. Cartesian robots are also extremely precise because of the
accuracy and arrangements of the prismatic bearings. Cartesian robots can move
through X, Y, and Z axes. The length of each axis can be adjusted depending on the
application. Cartesian robots are used for assembly and injection molding
applications.
Cylindrical robots have a combination of revolute and prismatic joints that allow
them to work well in round workspaces. Spherical robots, on the other hand, have a
joint configuration that allows the robot to move in a desired direction and then
extend to reach an object. Figure 3 shows a spherical robot. Spherical robots are
used for welding and material handling. A typical spherical robot has 4 to 6 revolute
joints.
SCARA robots are a type of cylindrical robot. SCARA stands for Selective Compliance
Arm for Robotic Assembly. The SCARA robot illustrated in Figure 4 has four axes of
movement. It can move through X, Y, Z coordinates and a fourth Theta Z
coordinate. Theta Z is a rotating axis that corresponds to the angle around the z-
axis of the tool at the end of the SCARA robot. SCARA robots are often used for
inserting electronic components into circuit boards. SCARA robots generally have
three parallel revolute joints and two parallel prismatic joints that are both in the Z
direction.
Figure 1. An articulated robot has revolute joints
only.
Figure 2. A Cartesian robot has prismatic joints
only.
Figure 3. This spherical robot can turn around on its
base and reach for an object.
Figure 4. SCARA robots can move through X, Y, Z
coordinates and a fourth Theta Z coordinate
corresponding to the end-effector.
The robotic arm is the most common type of industrial robot. However, there is a second
type of industrial robot known as the automatic guided vehicle (AGV). Unlike a robotic
arm, an AGV can move freely about the workspace. Instead of having a driver for
navigation, the AGV uses light reflectors, colored tape, or wires that are embedded in the
floor to guide it through a predetermined route.
There are four types of AGVs:
lTow vehicles, also known as tuggers (Figure 1), pull trailers loaded with material.
Tow vehicles are capable of pulling extremely heavy loads, some weighing up to
60,000 lbs. (27,215 kg). Tow vehicles do not load the materials; they simply
transport them.
lUnit load carriers (Figure 2) have powered decks that lift and lower to transport
pallets loaded with material.
lCart vehicles (Figure 3) are small, relatively inexpensive AGVs that can load material
like a unit load carrier or pull it like a tow vehicle. However, cart vehicles are usually
limited to loads of no more than 2,000 lbs. (907 kg).
lFork vehicles (Figure 4) lift and lower materials. Their load capacity can range from
1,200 to 5,000 lbs. (544 to 2,267 kg). Forks are available in different styles other
than the standard dual fork.
AGVs are extremely flexible in the distance and direction that they can move. You can find
AGVs in automotive, printing, chemical, medical and pharmaceutical, food and beverage,
distribution, paper, manufacturing, and warehousing applications.
Figure 1. A tow vehicle is capable of pulling
extremely heavy loads.
Figure 2. A unit load carrier has powered decks
that lift and lower.
Figure 3. A cart vehicle cannot pull loads
greater than 2,000 lbs. (907 kg).
Figure 4. Fork vehicles primarily lift and lower
materials.
In order to be considered a robot, a machine must have some form of artificial
intelligence. Artificial intelligence is simply a computer software program that contains
behavior rules, as shown in Figure 1. These rules tell the robot how to act as it learns
how to perform its job. For example, a robot could be programmed to move toward a
light source when light is detected by its photosensors. Or it could be programmed to
move away from any objects that come into contact with the robot’s feelers. Figure 2
shows how a robot learns to adjust its path after colliding with an object.
Like human intelligence, an artificial intelligence program controls different levels of
behavior. The lowest, most primitive level of artificial intelligence simply allows the robot
to move its mechanical parts. The next level controls the robot’s reflexes so it can
respond to its environment and make decisions based on the information detected by
its sensors. The highest level of artificial intelligence is devoted to the robot’s memory
and problem-solving abilities.
Figure 1. Artificial intelligence is simply a computer
software program. [Courtesy of Kawasaki Robotics
(USA), Inc.]
Figure 2. After colliding with an object, this robot
learns to adjust its path. (Courtesy of Kawasaki
Robotics (USA), Inc.)
Like a human worker, a robot must be trained to do its job correctly. While it is
possible for some robots to simply learn on their own by trial and error, most robots
are taught by humans. The three main methods for teaching robots are lead-through
programming, walk-through programming, and off-line programming.
In lead-through programming, shown in Figure 1, the robot is placed in "teach
mode" while the trainer uses a remote teach pendant to manipulate the robot through
the different steps of the job. This is the most common programming method. The
robot is moved manually via the teach pendant, which controls the robot axes.
In walk-through programming, shown in Figure 2, the trainer physically moves the
robot through different steps of the job process. The robot learns which positions it
must move through, and which functions it must perform. Because it involves physical
contact with the robot, walk-through programming is done inside the work envelope
of the robot. This is extremely hazardous. To ensure worker safety, the robot must
be placed in manual mode. In manual mode a robot cannot move unless the trainer
holds down a pushbutton.
Lead-through and walk-through teaching methods are considered online. They require
the robot to remain "on" in order to learn. Off-line programming, shown in Figure 3,
allows the trainer to work from a remote location. The trainer writes a program and
downloads it into the robot. From there, the program can be refined with lead-
through or walk-through programming.
Figure 1. In lead-through programming the trainer
uses a remote teach pendant to program the robot.
Figure 2. In walk-through programming the trainer
physically moves the robot through different steps
of the job process.
Figure 3. In offline programming a trainer writes a
program from a remote location and downloads it
into the robot.
Industrial robots can be extremely fast and strong. When robot accidents occur, they can
result in serious injury, loss of limb, and even the death of a worker. Never enter the
robot’s work envelope unless it is absolutely necessary. The work envelope or work
cell is the defined area of space through which a robot can move. A worker within the
robot’s work envelope can be struck by the robot or crushed between equipment, as
shown in Figure 1. Even if you are familiar with the work pattern of the robot, do not
assume that you can predict its movements. Changes to the robot’s program, program
errors, and equipment malfunctions can cause sudden, unpredictable movements by the
robot.
If you must be inside the robot’s work envelope for installation, programming, or
maintenance, use a lockout/tagout key like the one in Figure 2 to prevent the robot
from starting up. Always read the robot’s user manual and make sure you are familiar
with the manufacturer’s safety guidelines. In addition, always wear personal protective
equipment (PPE) such as a hard hat, safety glasses, and steel-toed boots.
Workers must be trained and supervised in the operation, maintenance, and emergency
procedures of the robot. Workers should learn and comply with the guidelines from the
Occupational Safety and Health Administration (OSHA), the National Institute for
Occupational Safety and Health (NIOSH), and the American National Standards
Institute (ANSI). Safety devices such as security gates, pressure mats, alarms, and
emergency stop circuitry should be installed near the robot as well. Figure 3 shows a
robot secured behind a safety fence.
Figure 1. Within a robot’s work envelope, a
worker is in danger of being struck or crushed.
Figure 2. Use a lockout/tagout key whenever
you are inside the robot’s work envelope.
Figure 3. Install safety devices near the robot to
protect workers. [Courtesy of Kawasaki Robotics
(USA), Inc.]
For the past several years, sales of industrial robots have risen steadily. It is likely
that the use of robots in industry will continue to increase. In addition to various
manufacturing industries, the military is also expected to increase its use of robots.
One of the most important developments in robot technology is the addition of vision
to the robot’s abilities. Sensors and cameras on the robot allow it to see its
environment, as shown in Figure 1. When coupled with the memory provided by a
computer, vision allows the robot to find specific objects and features to determine
their position. This allows the robot to pick randomly positioned and oriented
objects.
As continuing advancements are made in developing artificial intelligence, there will be
more opportunities for robots to assist people. New types of robots may be
developed for personal use. Figure 2 shows a robot that can perform the simple
household chore of vacuuming. Someday, having your own robot may be as common
as having a cellular phone.
Figure 1. The addition of vision sensors, such as
cameras, is an important development in robot
technology.
Figure 2. This Roomba vacuum cleaner runs without
an operator. (Courtesy of Larry D. Moore)
As the use of robots increases in manufacturing, there will also be an increased need for
robot technicians to maintain the robots. Robot technicians may be required by an
employer to earn at least a two-year degree in robotics, engineering, or computer science.
Some of the day-to-day tasks performed by a robot technician include:
lAssisting the robot engineer in designing end-of-arm tools and accessory equipment
for specific tasks.
lInspecting electronic components and other robot parts for defects.
lInstalling and testing the robot.
lInstalling safety systems for the robot.
lTraining robot operators, troubleshooting problems, and providing technical support.
lDisassembling the robot for service and repair.
The working conditions for a robot technician can vary. A technician may be required to
travel to different locations. He or she may work on the robot in a clean, quiet test lab, like
the one in Figure 1, or in a dirty, noisy factory. If there is a problem with the robot or there
is an installation deadline, the technician may be required to work overtime.
Figure 1. The working conditions for a robot
technician can vary.
Robots improve worker safety by relieving workers from dangerous and tedious
jobs, as shown in Figure 1. For example, robots relieve workers from handling harsh
chemicals or radioactive parts. They can also help to prevent repetitive motion
injuries by performing repetitive tasks.
The growth of robotics means that there will be a greater demand for workers who
can operate and maintain robots. Robots also provide economic advantages to
employers. Robots do not take sick days or vacation days, and they never get tired.
They can work 24 hours a day without stopping. In addition, robots can repeat a
task many times without varying the quality or consistency of the work. This reduces
waste, increases productivity, and improves product quality. Moreover expenses
associated with defective parts and workers compensation claims are eliminated
when robots do the work.
Despite the many benefits of using robots in the workplace, there are some
disadvantages to using robots. In past studies, the Bureau of Labor and Statistics
predicted that increased automation in the workplace could lead workers to feel
stressed, lonely, and like they lost of control of the process. Moreover, installing
robots to perform menial tasks does not always mean that human workers are
advanced to higher-functioning tasks. Sometimes workers are merely shifted to a
different low-skill task.
The cost of buying and installing a robot like the one in Figure 2 can be very high.
There is an initial investment in support technology for the robot, and the robot
itself can cost $200,000 or more. It takes time to program and troubleshoot a robot
after it has been installed. In addition, workers must be trained to operate and
maintain the robot.
Figure 1. This robot can stack containers on a pallet
all day without getting bored, tired, or injured.
[Courtesy of Kawasaki Robotics (USA), Inc.]
Figure 2. The initial cost of installing this plastic
molding robot may be very high. [Courtesy of
Kawasaki Robotics (USA), Inc.]
An industrial robot is a programmable mechanical device used in place of a person to
perform dangerous or repetitive tasks. Industrial robots were first used in the 1960s.
One of the most common industrial applications for robots today is welding.
The basic components of a robot are the power supply, controller, teach pendant, axis
control module, input/output modules, and mechanical body. A robot’s body consists of
a base, shoulder, elbow, arm, wrist, and an end-of-arm-tool. Robots use different
coordinate systems to determine where to move. The Cartesian coordinate system
defines the location of a single point in three-dimensional space using X, Y, and Z axes.
World coordinates have the robot’s mounting base as a point of origin. Tool
coordinates have the tool at the end of the robot’s arm as the point of origin.
Robotic arms come in different styles. Articulated robots closely resemble a human arm.
Cartesian robots have prismatic joints only. Cylindrical robots have a combination of
revolute and prismatic joints that allow them to work well in round workspaces.
Spherical robots have a joint configuration that allows the robot to move in a desired
direction and then extend to reach an object. SCARA robots can move through X, Y, Z
coordinates and a fourth Theta Z coordinate.
Automatic guided vehicles can move freely about the workspace. Tow vehicles pull
trailers loaded with material. Unit load carriers have powered decks that lift and lower to
transport pallets loaded with material. Cart vehicles can load material like a unit load
carrier or pull it like a tow vehicle. Fork vehicles lift and lower materials.
Artificial intelligence is a computer software program that contains behavior rules for
robots. Robots are trained to do their jobs through different programming methods. In
lead-through programming the trainer uses a teach pendant to program the robot. In
walk-through programming, the trainer physically moves the robot through the job
process. In off-line programming the trainer writes a program remotely and downloads
it into the robot.
Robot accidents can result in serious injury and even the death of a worker. Therefore,
workers must learn the proper operation, maintenance, and emergency procedures of
the robot.
Figure 1. An industrial robot is composed of a
power supply, controller, axis control module, and
mechanical body.
Figure 2. A robotic arm typically include a base,
shoulder, arm, and end-effector.
Figure 3. Robot accidents can result in serious
injury and even the death of a worker.
Term Definition
alloy A uniform mixture of two or more materials, one of which must be a metal. Industrial robots are usually
composed of alloys.
American National Standards
Institute An organization that oversees industry standards for commercial products and services. ANSI provides
guidelines for manufacturing, installing, and safeguarding robotic systems.
articulated robot A type of robotic arm that closely resembles a human arm. The arm of an articulated robot has revolute joints
and the number of joints can vary.
artificial intelligence A computer software program that contains behavior rules for robots. Artificial intelligence is one of the
characteristics that distinguishes robots from other programmable machines.
assembly The process of fitting components together into a larger or completed part.
automatic guided vehicle An industrial robot that can move freely about the workspace. AGVs can take the form of carts, forklifts, or
tow vehicles.
axes The plural of axis. An axis is an imaginary straight line or circle used to describe the location or movement of
an object in the Cartesian coordinate system.
axis control module A component that allows a robot to move in different directions. The axis control module also controls the
velocity and torque of the robotic arm.
cabinet An enclosure containing a robot's controller, axis control module, input/output module, and power supplies.
camera A device used to capture still images, such as photographs, or moving images, such as videos. Cameras give
a robot vision.
cart vehicle A small AGV that can load material like a unit load carrier or pull it like a tow vehicle. Cart vehicles are usually
limited to loads of no more than 2,000 lbs. (907 kg).
Cartesian coordinate system A numerical system that describes the location of an object by numerically expressing its distance from a
fixed position along three linear axes.
Cartesian robot A type of robotic arm that has prismatic joints only. The linear movement of the joints gives the Cartesian
robot a highly rigid structure that allows it to lift heavy objects.
clean room A room in which temperature, humidity, and air pressure are controlled and maintained at a specific level.
controller The main device that processes information and carries out instructions in a robot. Also known as the CPU, or
processor.
cylindrical robot A type of robotic arm that has a combination of revolute and prismatic joints. Cylindrical robots work well in
round workspaces.
degrees of freedom The available ways a component can move in three-dimensional space. Robots typically have 3 to 6 degrees of
freedom.
dross A type of scum formed by oxidation at the surface of molten metals.
end-effector The end component of a robotic arm that is shaped like a hand or like a specialized tool. Also known as end-
of-arm tool (EOAT).
end-of-arm tool The end component of a robotic arm that is shaped like a hand or like a specialized tool. Also known as an
end-effector.
feeler A sensor on a robot that responds to touch or pressure.
fork vehicle A type of AGV that can lift and lower materials. Forks are available in different styles other than the standard
dual fork.
gripper A hand-shaped end-effector designed for seizing and holding.
industrial robot A programmable mechanical device that is used in place of a person to perform dangerous or repetitive tasks
with a high degree of accuracy.
input/output module The jack where an input/output device is physically connected to a robot. Inputs and outputs allow the robot
to interact with its environment.
integrated circuit A miniaturized electronic circuit. The development of integrated circuits helped to improve the performance of
industrial robots.
intelligence The ability to learn, reason, and solve problems.
joint The location at which two or more parts of a robotic arm make contact. Joints allow parts to move in different
directions.
lead-through programming A programming method in which a robot is placed in "teach mode" while the trainer uses a remote teach
pendant to manipulate the robot through the different steps of the job. Lead-through programming is the
most common programming method.
linear joint A joint that moves in a straight line across one axis. Also known as a prismatic joint.
linear movement Movement in a straight line across one axis.
link A fastener that joins or connects the parts of a robotic arm.
lockout/tagout A method of protecting employees from accidental robot startup through proper locking and labeling of
robots that are undergoing maintenance.
machine loading The process of loading raw materials into machinery for processing.
main power supply The power supply that provides voltage and current to a robot’s motor. A robot's main power supply is AC
run through a transformer.
manipulator A robotic arm. A manipulator is generally mounted on a platform or suspended from a track while the arm
reaches to various distances and locations.
material removal The process of removing substances or matter from a surface. Material removal processes include cutting,
grinding, deburring, deflashing, polishing, waterjet cutting, and routering.
materials handling The process of loading, unloading, placing, or manipulating material. Types of material handling include
machine tending, part transfer, packaging, and palletizing.
microcontroller A tiny computer that is self-sufficient.
National Institute for
Occupational Safety and
Health
The federal agency responsible for conducting research and making recommendations for the prevention of
work-related injury and illness. Also known as NIOSH.
Occupational Safety and
Health Administration A government agency that helps employers reduce injuries, illnesses, and deaths in the workplace. Also
known as OSHA.
off-line programming A programming method in which a trainer writes a program from a remote location and downloads it into a
robot. Off-line programming can be refined with lead-through or walk-through programming.
origin The fixed, central point in the Cartesian coordinate system. The origin has a numerical value of zero.
packaging The process of assembling containers and components for shipping and storage.
palletizing The process of placing and securing containers or objects on pallets.
part transfer A type of material handling in which parts are transferred from one location to another.
personal protective
equipment Any of various safety equipment that workers wear or use to prevent injury in the workplace. Safety glasses
are common personal protective equipment (PPE).
pick and place The process of picking up an object or part in one location and placing it in another location.
power supply unit A separate power supply that provides DC voltage to a robot’s outputs and controller.
prismatic joint A joint that moves in a straight line across one axis. Also known as a linear joint.
revolute joint A joint that rotates around more than one axis.
right-hand rule A quick reference that shows the X-, Y-, and Z-axes. A person displays his or her right hand, and the first
three fingers from the right each represent the X-, Y-, and Z-axis in order.
robot technician A person who installs, services, troubleshoots, maintains, and repairs robots and automated production
systems.
robotic arm An arm-shaped robot generally mounted on a platform or suspended from a track while the arm reaches to
various distances and locations. Also known as a manipulator.
SCARA robot Selective Compliance Arm for Robotic Assembly. A type of cylindrical robot that has 4 axes of movement: X,
Y, Z, and Theta Z.
sensor A device that detects the presence or absence of an object, or certain properties of that object, and provides
feedback. Sensors allow robots to interact with their environment.
servomotor A type of motor used in applications that require precise positioning. Servomotors can move loads in excess
of 50 hp.
spherical robot A type of robotic arm that has a joint configuration that allows the robot to move in a desired direction and
then extend to reach an object. A typical spherical robot has 4 to 6 revolute joints.
spray painting Applying paint with a sprayer. Spray paint applications include painting, sealing, and coating.
stepper motor A type of motor that uses a permanent magnetic field to rotate. Stepper motors can rotate forward or
reverse, but they cannot move large loads.
teach pendant A hand-held device that can be used to program a robot and control its movements.
Theta Z coordinate A rotating axis that corresponds to the angle around the z-axis of the tool at the end of a SCARA robot.
tool coordinates A coordinate system that uses the tool at the end of the robot's arm as the point of origin.
tow vehicle A type of AGV that pulls trailers loaded with material. Tow vehicles are capable of pulling extremely heavy
loads.
transformer A device that transfers electrical energy from one circuit to another, without changing the frequency.
transistor A tiny electrical device that amplifies electrical signals and switches current on and off.
tugger Another name for a tow vehicle. Tuggers pull trailers loaded with material.
unit load carrier A type of AGV that has powered decks that lift and lower to transport pallets loaded with material.
unmanned aerial vehicle A robotic airplane that can fly without an onboard pilot.
walk-through programming A programming method in which the trainer physically moves the robot through different steps of the job
process.
welding A joining process that uses heat, pressure, and/or chemicals to fuse two materials together permanently.
Robots are used for welding in the automotive industry.
work cell The defined area of space through which a robot can move. Also known as the work envelope.
work envelope The defined area of space through which a robot can move. Also known as the work cell.
world coordinates A coordinate system that uses the robot’s mounting base as a point of origin.
X-axis The linear axis representing side-to-side movement in a robot.
Y-axis The linear axis representing back and forth movement in a robot.
Z-axis The linear axis that represents up and down movement in a robot.
Copyright © 2009 Tooling U, LLC. All Rights Reserved.
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