The document discusses industrial robots and automation. It defines an industrial robot as a reprogrammable, multifunctional manipulator designed to move material, parts, tools, or devices through variable programmed motions to perform tasks. Robots can be classified as a form of programmable automation. The document covers various topics related to industrial robots including types of automation, robot components, configurations, drives, and technical features like work volume and precision of movement.

1. Department of
Mechanical
Engineering
Unit title RT
ROBOTTECHNOLOGY

2. INDUSTRIAL
ROBOTS:
 Automation and robotics are closely related
technologies.
 Automation is concerned with the use of mechanical,
Electronics and computer based systems in the
operation and control of production.
 Examples of this technology include transfer lines,
mechanized assembly machines, feedback control
systems, NC machine tools and robots.
 Accordingly, robotics is a form of industrial automation.

3. AUTOMATION
AND
ROBOTICS:
 There are three broad classes of industrial automation:
1. Fixed automation
2. Programmable automation
3. Flexible automation

4. Relationship
between fixed
automation,
programmable
automation and
flexible
automation

5.  Of the three types of automation, robotics
coincides most closely with programmable
automation.
 An industrial robot is a general-purpose,
programmable machine which possesses
certain anthropomorphic, or humanlike,
characteristics.
 The most typical humanlike characteristic
or present-day robots is their movable
arms.
 The robot can be programmed to move its
arm through a sequence of motions in
order to perform some useful task.
 The programming feature allows robots to
be used for a variety of different industrial
operations, many of which involve the
robot working together with other pieces of
automated or semi automated equipments.
 These operations include machine loading
and unloading, spot welding and spray
painting.
RT

6.  The “official” definition of an industrial
robot is provided by the Robotics
Industries Association (RIA), formerly the
Robotics Institute of America (RIA):
 “An industrial robot is a reprogrammable,
multifunctional manipulator designed to
move material, parts, tools, or special
devices through variable programmed
motions for the performance of a variety of
tasks.”
 This definition reinforces that industrial
robots should be classified as a form of
programmable automation.
 While the robots themselves are examples
of programmable automation, they are
sometimes used in flexible automation and
even fixed automation systems.
RT

7. ROBOT
ANATOMY:
 Robot anatomy is concerned with the physical
construction of the body, arm and wrist of the machine.
 Generally, robot body is attached to the base and the arm
assembly is attached to the body.
 At the end of the arm is the wrist.
 The wrist consists of a number of components that allow
it to be oriented in a variety of positions.
 Relative movements between the various components of
the body, arm and wrist are provided by a series of joints.
 These joint movement usually involve either rotating or
sliding motions.

8.  The body, arm and wrist assembly is sometimes called
the manipulator.
 Attached to the robot’s wrist is a hand. The technical
name for the hand is “End effector”.
 The end effector is not considered as the part of the
robot’s anatomy.
 The arm and body joints of the manipulator are used to
orient the end effector.

9. CLASSIFICATION
OF ROBOTS
 The following is the classification of
robots according to the Japanese
Industrial Robot Association (JIRA):
1. Class 1: Manual Handling Device
- A device with multiple degrees of freedom
that is actuated by an operator.
2. Class 2: Fixed sequence Robot:
- A device that performs the successive
stages of a task according to a
predetermined, unchanging method and is
hard to modify.
3. Class 3: Variable-Sequence Robot:
- Same as class 2, but easy to modify.

10. 4. Class 4: Playback Robot:
- A human operator performs the task manually
by leading the robot, which records the
motions for later playback.
- The robot repeats the same motions
according to the recorded information.
5. Class 5: Numerical Control Robot:
- The operator supplies the robot with a
movement program rather than teaching it the
task manually.
6. Class 6: Intelligent Robot:
- A robot with the means to understand its
environment and the ability to successfully
complete a task despite changes in the
surrounding conditions under which it is to
be performed.

11. ADVANTAGES
AND
DISADVANTAGES
OF ROBOT:
Advantages:
 Robotics and automation can, in many situations,
increase productivity, safety, efficiency, quality and
consistency of products.
 Robots can work in hazardous environments without the
need for life support, comfort, or concern about safety.
 Robots needs no environmental comfort, such as
lighting, air conditions, ventilation, and noise protection.
 Robots work continuously without experiencing fatigue
or boredom, do not get mad, do not have hangovers, and
need no medical insurance or vacation.

12.  Robots have repeatable precision at all
times, unless something happens to them
or unless they wear out.
 Robots can be much more accurate than
humans. Typical linear accuracies are a
few thousands of an inch. New wafer-
handling robots have micro inch
accuracies.
 Robots and their accessories and sensors
can have capabilities beyond that of
humans.
 Robot can process multiple stimuli or
tasks simultaneously. Humans can only
process one active stimulus.
 Robot replace human workers creating
economic problems, such as lost salaries,
and social problems, such as
dissatisfaction and resentment among
workers.
ADVANTAGES
AND
DISADVANTAGES
OF ROBOT:

13. Disadvantages
 Robots lack capability to respond in emergencies, unless
the situation is predicted and the response is included in
the system. Safety measures are needed to ensure that
they do not injure operator and machines working with
them. This includes:
- Inappropriate or wrong responses
- A lack of decision making power
- A loss of power
- Damage to the robot and other devices
- Human injuries
ADVANTAGES
AND
DISADVANTAGES
OF ROBOT:

14.  Robots, although superior in certain senses, have
limited capabilities in
- Degrees of freedom
- Dexterity
- Sensors
- Vision systems
- Real-time response
 Robots are costly, due to
- Initial cost of equipment
- Installation costs
- Need for training
- Need for programming

15. ROBOT
COMPONENTS:

16. 1. Manipulator or Rover:
- This is the main body of the robot and
consists of the links, the joints, and other
structural elements of the robot.
2. End effector:
- This is the part that is connected to the
last joint (hand) of a manipulator, which
generally handles objects, makes
connection to other machines, or
performs the required task.
3. Actuators:
- Actuators are the “muscles” of the
manipulators. Common types of actuators
are servomotors, stepper motors,
pneumatic cylinders and hydraulic
cylinders.
ROBOT
COMPONENTS:

17. 4. Sensors:
- Sensors are used to collect information
about the internal state of the robot or to
communicate with the outside
environment.
- Robots are equipped with external sensory
devices such as a vision system, touch
and tactile sensors, speech synthesizers
etc. which enable the robot to
communicate with the outside world.
5. Controller
- The controller is rather similar to
cerebellum and although it does not have
the power of brain, it still controls motion.
- The controller receives its data from the
computer, controls the motion of the
actuators and coordinates the motions
with the sensory feedback information.
ROBOT
COMPONENTS:

18. 6. Processor:
- The processor is the brain of robot.
- It calculates the motions of the robot’s joints, determines
how much and how fast each joint must move to achieve
the desired location and speeds, and oversees the
coordinated actions of the controller and sensors.
- Processor is generally a computer which works like all
other computers, but is dedicated to a single purpose.
ROBOT
COMPONENTS:

19. 7. Software:
- There are perhaps three groups of software that are used
in robot.
- One is operating system, which operates computer.
- The second is the robotic software, which calculates the
necessary motions of each joint based on the kinematic
equations of the robot. This information is sent to the
controller.
- The third group is the collection of routines and
application programs that are developed in order to use
the peripheral devices of the robots, such as vision
routines, or to perform specific tasks.
ROBOT
COMPONENTS:

20. ROBOT PHYSICAL
CONFIGURATIONS:
 Industrial robots are available in a wide variety of sizes,
shapes and physical configurations.
 The vast majority of today’s commercially available
robots possess one of the four basic configurations:
1. Polar configuration
2. Cylindrical configuration
3. Cartesian coordinate configuration
4. Jointed-arm configuration

21. 1. POLAR
CONFIGURATION:
 The polar configuration uses a telescoping
arm that can be raised or lowered about a
horizontal pivot.
 The pivot is mounted on a rotating base.
 These various joints provide the robot with
the capability to move its arm within a
spherical space, and hence the name
“spherical coordinate robot” is sometimes
applied to this type.
 A number of commercial robots posses the
polar configuration.
 Examples –
- Unimate 2000 series
- MAKER 110

22. 2. CYLINDRICAL
CONFIGURATION:
 The cylindrical configuration, uses a
vertical column and a slide that can be
moved up and down along the column.
 The robot arm is attached to the slide
so that it can be moved radially with
respect to the column.
 By rotating the column, the robot is
capable of achieving a work space that
approximates a cylinder.

23. 3. CARTESIAN COORDINATE CONFIGURATION:
 The Cartesian coordinate
robot, uses three
perpendicular slides to
construct the x, y and z
axes.
 Other name are sometimes
applied to this configuration,
including ‘xyz robot’ and
‘rectilinear robot’.
 By moving the three slides
relative to one another, the
robot is capable of operating
within a rectangular work
envelope.

24.  Examples-
IBM RS-1 robot (Model 7565)
 The RS-1, because of its appearance
and construction, is occasionally
referred to as a “box” configuration.
 “Gantry” robot is another name used
for Cartesian robot that are generally
large and possess the appearance of a
gantry type crane.

25. 4. JOINTED ARM
CONFIGURATION:
 This configuration is similar to that
of human arm.
 It consists of two straight
components, corresponding to the
human forearm and upper arm,
mounted on a vertical pedestal.
 These components are connected by
two rotary joints corresponding to
the shoulder and elbow.
 A wrist is attached to the end of the
forearm, thus providing several
additional joints.

26.  A special version of the jointed arm robot is the SCARA,
whose shoulder and elbow joints rotate about vertical
axes.
 SCARA stands for -
‘Selective Compliance Assembly Robot Arm’.
 This configuration provides substantial rigidity for the
robot in the vertical direction, but compliance in the
horizontal plane.
 This makes it ideal for many assembly tasks.

27. COMPARISION OF
PHYSICAL
CONFIGURATIONS:
 There are relative advantages and disadvantages to
the four basic robot anatomies simply because of
their geometries.
 In terms of repeatability of motion (the capability to
move to a taught point in space with minimum
error), the box-frame cartesian robot probably
possesses the advantage because of its inherently
rigid structure.
 In terms of reach (ability of the robot to extend its
arm significantly beyond its base), the polar and
jointed are configuration have the advantage.
 The cylindrical configuration and the gantry xyz
robot can be designed for high-rigidity and load-
carrying capacity.
 For machine-loading applications, the ability of the
robot to reach into a small opening without
interference with the sides of the opening is
important. The polar configuration and the
cylindrical configuration possess a natural
geometric advantage in terms of this capability.

28. ROBOTIC
POWER
SOURCES:
 Commercially available industrial robots are powered
by one of the three types of drive systems.
1. Hydraulic drive
2. Electric drive
3. Pneumatic drive
 Hydraulic drive and electric drive are the two main
types of drives used on more sophisticated robots.

29. HYDRAULIC
DRIVE:
 Hydraulic drive is generally associated with larger robots,
such as the Unimate 2000 series.
 The usual advantage of the hydraulic drive system are that
it provides the robot with greater speed and strength.
 The disadvantages of the hydraulic drive system are that it
typically adds to the floor space required by the robot, and
that a hydraulic system is inclined to leak oil which is a
nuisance.
 Hydraulic drive systems can be designed to actuate either
rotational joints or linear joints.
 Rotary vane actuators can be used to accomplish linear
motion.

30. ELECTRIC
DRIVE:
 Electric drive systems do not generally
provide as much speed or power as hydraulic
system.
 However, the accuracy and repeatability of
electric drive robots are usually better.
 Consequently, electric robots tend to be
smaller, requiring less floor space, and their
applications tend toward more precise work
such as assembly.
 The MAKER 110 is an example of an electric
drive robot that is consistent with these
tendencies.
 Electric drive robots are actuated by dc
stepping motors or dc servomotors. These
motors are ideally suited to the actuation of
rotational joints through appropriate drive
train and gear systems.
 Electric motors can also be used to actuate
linear joints (telescoping arms) by means of
pulley systems or other translational
mechanisms.

31.  The economics of the two types of
drive systems are also a factor in the
decision to utilize hydraulic drive on
large robots and electric drive on
smaller robots.
 It turns out that the cost of an electric
motor is much more proportional to
its size, whereas the cost of a
hydraulic drive system is somewhat
less dependent on its size.
 As shown in the figure, there is a
hypothetical break-even point, below
which it is advantageous to use
electric drive and above which it is
appropriate to use hydraulic drive.
 So, there is a trend in the design of
industrial robots toward all electric
drives, and away from hydraulic
robots.

32. Cost vs. size
for electric
drive and
hydraulic
drive

33. PNEUMATIC
DRIVE:
 Pneumatic drive is generally reserved for smaller robots
that possess fewer degrees of freedom (two- to four-
joint motions).
 These robots are often limited to simple “pick and
place” operations with fast cycles.
 Pneumatic power can be readily adapted to the actuation
of piston devices to provide translational movement of
sliding joints.
 It can also be used to operate rotary actuators for
rotational joints.

34. TECHNICAL
FEATURES:
1. Work volume
2. Precision of movement
a) Spatial resolution
b) Accuracy
c) Repeatability
3. Speed of movement
4. Weight carrying capacity (pay
load)

35. WORK
VOLUME:
 The term "work volume" refers to the space within which
the robot can operate.
 To be technically precise, the work volume is the spatial
region within which the end of the robot's wrist can be
manipulated.
 Robot manufacturers have adopted the policy of defining
the work volume in terms of the wrist end, with no hand
or tool attached.
 The work volume of an industrial robot is determined by
its physical configuration, size and the limits of its arm
and joint manipulations.

36.  The work volume of a Cartesian
coordinate robot will be
rectangular.
 The work volume of a cylindrical
coordinate robot will be cylindrical.
 A polar coordinate configuration
will generate a work volume which
is a partial sphere.
 The work volume of a jointed arm
robot will be somewhat irregular,
the outer reaches generally
resembling a partial sphere.
WORK
VOLUME:

37. The work
volumes for
various
anatomies
(a) polar (b)
cylindrical (c)
cartesian

38. PRECISION OF
MOVEMENT:
 The precision with which the robot can move the end of
its wrist is a critical consideration in most applications.
 In robotics, precision of movement is a complex issue,
and it is described as three attributes:
1. Spatial resolution
2. Accuracy
3. Repeatability
 These attributes are generally interpreted in terms of the
wrist end with no end effector attached and with the arm
fully extended.

39. SPATIAL
RESOLUTION:
 The term "spatial resolution" refers to the smallest
increment of motion at the wrist end that can be
controlled by the robot.
 This is determined largely by the robot's control
resolution, which depends on
its position control system and/or its feedback
measurement system.
 In addition, mechanical inaccuracies in the robot's
joints would tend to degrade its ability to position its
arm.
 The spatial resolution is the sum of the control
resolution plus these mechanical inaccuracies.

40.  The factor determining control resolution are the range
of movement of the arm and the bit storage capacity in
the control memory for that movement.
 The arm movement must be divided into its basic
motions or degrees of freedom, and the resolution of
each degree of freedom is figured separately. Then the
total control resolution is the vector sum of each
component.

41. ACCURACY:
 The accuracy of the robot refers to its
capability to position its wrist end (or a tool
attached to the wrist) at a given target point
within its work volume.
 Accuracy is closely related to spatial
resolution, since the robot's ability to reach
a particular point in space depends on its
ability to divide its joint movements into
small increments.
 According to this relation, the accuracy of
the robot would be one half the distance
between the two adjacent resolution points.
 The robot's accuracy is also affected by
mechanical inaccuracies, such as
deflection of its components, gear
inaccuracies, and so worth.

43. REPEATABILITY:
 This refers to the robot's ability to position its
wrist end (or tool) back to a point in space
that was previously taught.
 Repeatability is different from accuracy.
 The robot was initially programmed to move
the wrist end to the target point T. Because it
is limited by its accuracy, the robot
was only capable of achieving point A. The
distance between points A and T is the
accuracy.
 Later, the robot is instructed to return to this
previously programmed point A. However,
because it is limited by it repeatability, it is
only capable of moving to point R.
 The distance between points R and A is a
measure of the robot's repeatability.
 As the robot is instructed to return to the
same position in subsequent work cycles, it
will not always return to point R, but instead
will form a cluster of positions about point A.

44. Illustration
of
Repeatabili
ty versus
accuracy
 Repeatability errors form a
random variable.
 In general, repeatability will be better
than accuracy.
 Mechanical inaccuracies in the robot‘s
arm and wrist
components are principal sources of
repeatability errors.

45. END
EFFECTORS:
 In the terminology of robotics, an end
effector can be defined as a device which is
attached to the robot's wrist to perform a
specific task.
 The task might be work part handling, spot
welding, spray painting, or any of a great
variety of other functions.
 The end effector is the special-purpose
tooling which enables the robot to perform a
particular job.
 It is usually custom engineered for that job,
either by the company that owns the robot or
by the company that sold the robot.
 Most robot manufacturers have engineering
groups which design and fabricate end
effectors or provide advice to their
customers on end effector design.
 For purposes of organization, we will divide
the various types of end effectors into two
categories:
 grippers and tools

46. GRIPPERS:
 Grippers are used to hold either work parts
(in pick-and-place operations, machine
loading, or assembly work) or tools.
 There are numerous alternative ways in
which the gripper can be designed. The most
appropriate design depends on the work part
or substance being handled. The following is
a list of the most common grasping methods
used in robot grippers :
- Mechanical grippers, where friction or the
physical configuration of the gripper retains
the object
- Suction cups (also called vacuum cups),
used for flat objects Magnetized gripper
devices, used for ferrous objects
- Hooks, used to lift parts off conveyors
- Scoops or ladles, used for fluids, powders,
pellets, or granular substances

47. Sample gripper designs
(a) pivot action gripper;
(b) slide action gripper;
(c) double gripper-pivot action mechanism;
(d) vacuum-operated hand
GRIPPERS:

48. OTHER TYPES
OF GRIPPERS:
1. Vacuum cups
2. Magnetic grippers
3. Adhesive grippers
4. Hooks, scoops and other miscellaneous devices.

49. Gripper

51. TOOLS AS END
EFFECTOR:
 There are a limited number of applications
in which a gripper is used to grasp tool
and use it during the work cycle.
 In most applications where the robot
manipulates a tool during the cycle, the
tool is fastened directly to the robot
wrist becomes the end effector.
 A few examples of tools used with robots
are the following:
- Spot welding gun
- Arc welding tools (and wire-feed
mechanisms)
- Spray painting gun
- Drilling spindle
- Routers, grinders, wire brushes
- Heating torches

52. WORK
CELL
CONTROL:
 Industrial robots usually work with other things: processing
equipment, work part conveyors, tools, and perhaps, human
operators.
 Some of the activities occur sequentially, while others take
place simultaneously.
 To make certain that the various activities are coordinated and
occur in the proper sequence, a device called the work cell
controller is used (another name for this is workstation
controller).
 The work cell controller usually resides within the robot and
has overall responsibility for regulating the activities of the
work cell components.

54. SENSORS:
 Sensors are used to collect information about the internal
state of the robot or to communicate with the outside
environment.
 In a robot, as the links and joints move, sensors such as
potentiometers, encoders and resolvers send signals to
the controller that allow it to determine where each joint
is.
 The sensors may be similar in function to that of humans,
such as vision, touch, and smell.
 In some cases, the sensors may be something humans
do not have, such as radioactive sensor.

55. SENSOR
CHARACTERISTICS:
 The characteristics of sensors determine the
performance, economy, ease of application,
and applicability.
1. Accuracy:
Accuracy is defined as how close the output
of sensor is to the expected value.
2. Repeatability:
If the sensor’s output is measured a number
of times in response to the same input, the
output may be different each time.
Repeatability is a measure of how varied the
different outputs are relative to each other.
3. Range:
Range is the difference between the smallest
and the largest outputs the sensor can
produce, or the difference between the
smallest and the largest inputs with which it
can operate properly.

56. 4. Response time (Speed of Response):
 Response time is the time that a sensor’s
output requires to reach a certain percentage
of the total change. It is usually expressed in
percentage of total change, such as 95%.
 It is also defined as the time required to
observe the change in output as a result of a
change in input.
5. Sensitivity:
The sensitivity is the ratio of a change in
output in response to a change in input.
Highly sensitive sensors will show larger
fluctuations in output as a result of
fluctuations in input, including noise.
6. Linearity:
Linearity represents the relationship between
input variations and output variations. Almost
all the devices in nature are somewhat
nonlinear, with varying degrees of
nonlinearity. Certain devices can be assumed
to be linear within a certain range of
operation.
SENSOR
CHARACTERISTICS:

57. 7. Interfacing:
The sensor should be easy to interface with other
devices such as microprocessors and controller.
8. Reliability:
Reliability is the ratio of how many time a system
operates properly divided by how many times it is
tries.
9. Frequency response:
The larger the range of the frequency response,
the better the ability of the system to respond to
varying input.
10. Cost and Ease of Operation:
The cost of purchase, installation and operation
of sensor should be as low as possible. The
installation and operation of sensor should be
simple and easy.
11. Size and Weight:
The size and weight of the sensor should be as
small as possible.
SENSOR
CHARACTERISTICS:

58. TYPES OF SENSORS:
SENSORS
TECTILE OR CONTACT
SENSORS
TOUCH
SENSORS
FORCE
SENSORS
POSITION OR
DISPLACEMENT
SENSORS
NON-CONTACT
SENSORS
PROXIMITIY OR
RANGE
SENSORS
ROBOT VISION
SYSTEMS
VOICE
SENSORS

59. TACTILE
SENSORS:
 Tactile sensors are divided into following
categories.
1. Touch sensors
2. Force sensors
3. Position and displacement sensors
Touch sensors:
 Touch sensors are devices that send a
signal when physical contact has been
made.
 The simplest form of touch sensor is
microswitch, which either turns on or off
as contact is made.
 These sensors indicated and respond to
the presence or absence of an object.
They provide the binary output signals.

60. Force Sensors:
 Force sensors are used to measure the
magnitude of contact force.
 These sensors are analog type sensors in
which the output signal is proportional to
local force.
 Examples- Piezoelectric sensors, force
sensing resistors, strain gauges etc.
Position and Displacement sensors:
 Position sensors are used to measure
displacement, both rotary and linear, as well
as movements.
 In many cases the position information may
also be used to calculate velocities.
 Examples- Potentiometers, encoders, linear
variable differential transformers (LVDT),
resolvers etc.

61. PROXIMITY
SENSORS:
 Proximity sensors are used to determine
that an object is close to another object
before the contact is made.
 This noncontact sensing is useful in many
situation, from measuring the speed of a
rotor to navigating a robot.
 Examples- Magnetic and eddy current
sensors, optical, ultrasonic inductive and
capacitive.
VISION
SENSORS:
 Computerized visions systems will be an important
technology in future automated factories.
 Robot vision is made possible by means of a video
camera, a sufficient light source, and a computer
programmed to process image data.
 The camera is mounted either on the robot or in a
fixed position above the robot so that its field of
vision includes the robot's work volume.

62.  The computer software enables the vision
system to sense the presence of an object
and its position and orientation.
 Vision capability would enable the robot to
carry out the following kinds of operations:
- Retrieve parts which are randomly oriented
on a conveyor.
- Recognize particular parts which are
intermixed with other objects.
- Perform visual inspection tasks.
- Perform assembly operations which
require alignment.
 All of these operations have been
accomplished in research laboratories. It is
merely a matter of time and economics
before vision sensors become a common
feature in robot applications.

63. VOICE
SENSORS:
 Another area of robotics research is voice
sensing or voice programming.
 Voice programming can be defined as the
oral communication of commands to the
robot or other machine.
 The robot controller is equipped with a
speech recognition system which analyzes
the voice input and compares it with a set of
stored word patterns.
 When a match is found between the input
and the stored vocabulary word, the
robot performs some action which
corresponds to that word.
 Voice sensors would be useful in robot
programming to speed up the programming
procedure, just as it does in NC
programming.
 It would also be beneficial in especially
hazardous working environments for
performing unique operations such as
maintenance and repair work.

66. ACTUATORS:
 Actuators are the muscles of robots.
 If links and joints are considered as the skeleton of the
robot, the actuators, act as, muscles, which move or rotate
the links to change the configuration of robots.
 The actuators must have enough power to accelerate and
decelerate the links and to carry the loads, yet be light,
economical, accurate, responsive, reliable and easy to
maintain.

67. Types of
Actuators:
 Mechanical actuators
 Electric motors
- Servomotors
- Stepper motors
- Direct drive electric motors
 Hydraulic actuators
 Pneumatic actuators
 Shape memory metal actuators
 Magnetostrictive actuators

68. MECHANICAL
ACTUATORS:
 Mechanical actuators are classified into two
types:
1. Linear Mechanical actuators
2. Rotary Mechanical actuators
Linear Mechanical Actuators:
 Linear mechanical actuators are used to
actuate the linear manipulator joints of the
robot.
 Examples – Rack and pinion
- Recirculating ball screws
Rotary Mechanical Actuators:
 Examples – Timing belts
- Gear pairs
- Harmonic drives

69. ELECTRIC
MOTORS:
DC Motors:
 DC motors are common in industry and
are reliable and relatively powerful.
AC Motors:
 Electric AC motors are similar to DC
motor, except that the rotor is permanent
magnet, the stator houses the winding.
Direct Drive Electric Motors:
 These motors are designed to deliver a
very large torque at very low speeds and
with very high resolution.
 These motors are intended to be used
directly with a joint without any gear
reduction.
 Direct drive motors are still very expensive
and very heavy, but have impressive
characteristics.

70. Servomotors:
 In a servomotor, by varying current (or
corresponding voltage) the speed
torque balance can be maintained.
 A servomotor is DC, AC, brushless or
even stepper, motor with feedback that
can be controlled to move at a desired
speed for a desired angle of rotation.
Stepper Motors:
 Stepper motors are versatile, long-
lasting, simple motors that can be
used in many applications.
 In most applications, the stepper
motors are used without feedback.

71. HYDRAULIC
ACTUATORS:
 Hydraulic actuators offer a high power to
weight ratio, large forces at low speeds,
compatibility with microprocessor and
electronic controls and can be used in
extreme hazardous environments.
 A hydraulic system generally consists of
the following parts:
1. Hydraulic linear or rotary cylinders and
rams
2. A hydraulic pump
3. Electric motors
4. Cooling system
5. Reservoir
6. Valves and connecting hoses
7. Sensors

72. PNEUMATIC
ACTUATORS:
 A source of pressurized air is used to power
and drive linear or rotary cylinders, controlled
by manual or electrically controlled solenoid
valves.
 Pneumatic actuators are of linear or rotary
type.
 A linear pneumatic actuators are the single
acting or double acting pneumatic cylinders
used to actuate the linear joints of the robots.
 The cylinders are operated by compressed air
at about 35 to 70 bar pressure.
 High pressure compressed air runs the
pneumatic motors. The torque developed by
pneumatic motor actuates the rotary joints.

73. ROBOT
APPLICATIONS:
 General Application
Characteristics
1. Hazardous or uncomfortable
working conditions
2. Repetitive tasks
3. Difficult handling
4. Multishift operation

74. Application
Areas for
Industrial
Robots:
1. Material transfer
2. Machine loading
3. Welding
4. Spray coating
5. Processing operations
6. Assembly
7. Inspection

75. 1. MATERIAL
TRANSFER
 Simple pick and place operations
 Transfer of workparts from one conveyer to another
conveyer
 Palletizing operations, in which the robot takes parts from
a conveyor and loads them onto pallet in required pattern
and sequence
 Stacking operation
 Loading parts from a conveyor into cartons or boxes
 Depalletizing operations, in which the robot takes parts
which are arranged on a pallet and loads them onto a
conveyor

76. 2. MACHINE
LOADING
 Machine loading applications are material
handling operations in which the robot is
required to supply a production machine with
raw work parts and/or to unload the finish
parts form the machine.
 Machine loading is distinguish form a material
transfer operation by the fact that the robot
works directly with the processing
equipments.
 Production operations in which robot have
been successfully applied to perform the
machine loading and unloading function
includes:
- Die casting
- Injection (plastic) molidng
- Hot forging
- Upsetting or upset forging
- Stamping press operations
- Machining operations such as turning and
milling

77. 3. WELDING:  Spot welding
 Arc welding

78. 4. SPRAY
PAINTING
 Spray painting process poses certain health
hazards to the human operator. These are
- fumes and mist from the spraying operation
- noise from the spray nozzles
- fire hazard
- possible cancer dangers
 For these and other reasons, specialized
industrial robots are being used more and
more frequently to perform spray painting
operations.
 Advantages of using robot in this
applications are:
- safety
- Coating consistency
- Lower material usage
- Less energy used
- Greater productivity

79. 5. PROCESSING
OPERATIONS:
 Drilling
 Riveting
 Grinding
 Polishing
 Deburring
 Wire brushing
 Waterjet cutting

80. 6. ASSEMBLY:  Adaptable-programmable assembly system (APAS)
 PUMA (Programmable Universal Machine for
Assembly)
7. INSPECTION:
 Robots equipped with mechanical
probes, optical sensing capabilities, or
other measuring devices can be
programmed to perform dimensional
checking and other forms of inspection
operations.

81. ECONOMIC
ANALYSIS
FOR
ROBOTICS
 The economic analysis for any proposed robot project
is of considerable importance in most companies
because management usually decides whether to install
the project on the basis of this analysis.
 To perform the economic analysis of a proposed robot
project, certain basic information is needed about the
project.
 This information includes-
- the type of project being considered
- the cost of the robot installation
- the production cycle time
- savings and benefits resulting from the project

82. Cost data
required for
the
analysis:
 The cost data required to perform the
economic analysis of a robot project
divide into two types:
1. Investment costs:
- Robot purchase cost
- Planning and design cost
- installation cost
- Special tooling
- Miscellaneous costs
2. Operating costs:
- Direct labor cost
- Indirect labor cost
- Maintenance
- Utilities
- Training

83. INTERFACING A
VISION SYSTEM
WITH A ROBOT:
 Machine vision is concerned with the sensing
of vision data and its interpretation by
computer.
 The typical vision system consists of the
camera and digitizing hardware, a digital
computer and hardware and software
necessary to interface them with the robot.
 This interface hardware and software is often
referred to as preprocessor.
 The operation of the vision system consists of
three functions:
1. Sensing and digitizing image data
2. Image processing and analysis
3. Application
 Current typical application of machine vision
with robot are for inspection task in high
speed production line to accept or reject parts
made on the line. Unacceptable parts are
ejected from the line by some mechanical
device that is communicating with the vision
system.

84. INTELLIGENT
ROBOTS:
 Artificial Intelligence efforts aim at developing systems
that appear to behave intelligently. Often this is
described as developing machines that “think”.
 Typically this work is carried out as a branch of
computer science, although it also contains element of
psychology and mathematics.
 One of the problems involved with vision systems is the
representation of data within the system.
 Rather than store pictures of the parts within the vision
systems memory, certain features about the objects are
stored, such as perimeter, area, number of holes, and so
on.

85.  As the system become more complex and begin to be able
to deal in crowded three-dimensional environments it will
require greater intelligence on the part of the vision
system.
 Techniques have been developed which allow vision
systems to recognize specific types of objects even when
mixed together.
 These systems rely heavily on artificial intelligent methods
to increase their processing speed.