ROBOTICS AND MACHINE

VISION SYSTEM
 OBJECTIVE
To study the basic components of an
industrial robot and its specifications
To derive the kinematics, dynamics and
velocities equation for different robot
configurations
To manipulate the trajectory of robots and
program the robot for specific applications
To learn the machine vision systems
through image acquisition, processing and
analysis
 COURSE OUTCOMES
At the end of this course, student will be able to:
 Comprehend the basic components and total
functionality of an industrial robot
 Solve the kinematics, dynamics and velocity
equations for different configurations of the
manipulators
 Recognize different modes of trajectory planning
and robot programming for industrial applications
 Understand the role of machine vision system and
image processing techniques
HISTORY
INTRODUCTION
The term robot has its
origin in a Czech word
“robota” meaning
“forced labour”. It was
first introduced by the
playwright Karel Capek,
in a 1920 play
R.U.R(Rossum’s
Universal robot.
 Continued….

ROBOT INSTITUTE OF AMERICA

(RIA): A robot is a reprogrammable
multifunctional manipulator designed
to move material, parts, tools, or
specialized devices through variable
programmed motions for the
performance of a variety of tasks

Tele operators + numerically

controlled milling machines = Robot
Milestones in the History of Robotics
 1947 — the first servo electric powered tele operator is
developed
 1948 — a tele operator is developed incorporating force
feedback
 1949 — research on numerically controlled milling machine is
initiated
 1954 — George Devol designs the first programmable robot
 1956 — Joseph Engelberger, a Columbia University physics
student, buys the rights to
 Devol’s robot and founds the Unimation Company
 1961 — the first Unimate robot is installed in a Trenton, New
Jersey plant of General
 Motors to tend a die casting machine
 1961 — the first robot incorporating force feedback is developed
Sample of Teleoperation device
Tele operation architecture
 Continued….
 1963 — the first robot vision system is developed
 1971 — the Stanford Arm is developed at Stanford University
 1973 — the first robot programming language (WAVE) is
developed at Stanford
 1974 — Cincinnati Milacron introduced the T3 robot with
computer control
 1975 — Unimation Inc. registers its first financial profit
 1976 — the Remote Center Compliance (RCC) device for part
insertion in assembly is developed at Draper Labs in Boston
 1976 — Robot arms are used on the Viking I and II space
probes and land on Mars
 1978 — Unimation introduces the PUMA robot, based on
designs from a General Motors study
 Continued….
 1979 — the SCARA robot design is introduced in Japan
 1981 — the first direct-drive robot is developed at Carnegie-
Mellon University
 1982 — Fanuc of Japan and General Motors form GM Fanuc to
market robots in North America
 1983 — Adept Technology is founded and successfully markets
the direct drive robot
 1986 — the underwater robot, Jason, of the Woods Hole
Oceanographic Institute, explores the wreck of the Titanic, found
a year earlier by Dr. Robert Barnard.
 1988 — Staubli Group purchases Unimation from Westinghouse
 1988 — the IEEE Robotics and Automation Society is formed
 1993 — the experimental robot, ROTEX, of the German
Aerospace Agency was flown aboard the space shuttle Columbia
and performed a variety of tasks under both teleoperated and
sensor-based offline programming modes
 Continued….
 1996 — Honda unveils its Humanoid robot; a project begun in secret
in 1986
 1997 — the first robot soccer competition, RoboCup-97, is held in
Nagoya, Japan and draws 40 teams from around the world
 1997 — the Sojourner mobile robot travels to Mars aboard NASA’s
Mars Path Finder mission
 2001 — Sony begins to mass produce the first household robot, a
robot dog named Aibo
 2001 — the Space Station Remote Manipulation System (SSRMS) is
launched in space on board the space shuttle Endeavor to facilitate
continued construction of the space station
 2001 — the first telesurgery is performed when surgeons in New York
performed a laparoscopic gall bladder removal on a woman in
Strasbourg, France
 2001 — robots are used to search for victims at the World Trade
Center site after the September 11th tragedy
 2002 — Honda’s Humanoid Robot ASIMO rings the opening bell at the
New York Stock Exchange on February 15th
 Basic components of robot

Motion power unit Elbow Arm

2 3

6
4
1
Control unit
Shoulder Wrist

6 Revolute joints
= 6R robot Manipulator
A robot is a group of several subsystems each with its
own function:
Mechanical system By which the robot interacts with
the surrounding environment.
It usually performs one particular task. It consists of
actuators, joints, wrists, tools, etc. . .
Electrical system Consisting of sensors,
electrical/pneumatic/hydraulic actuators, computers,
etc. .
Control system This system receives high level
orders and translates them into commands for
actuators.
Sensor system It measures different physical
magnitudes so that control system is able to perform
the correct action.
Continued….
 Robot Laws

1. A robot may not injure a human

beings, or, through inaction, allow
one to come to harm.
2. A robot must obey the orders given
to it by human beings except where
such orders would conflict with the
first law.
3. A robot must protect its own
existence as long as such
protection does not conflict with the
First or Second Laws
 ROBOT LIKE DEVICES
- near relations
Prostheses: make use of either hydraulic or
servo motor actuators, utilize servo control
and have mechanical linkages.
To produce an action in such device
originates in brain of the human being.

Exoskeletons
Collection of mechanical linkages that are
made to surround either human limbs or
the entire human frame
Ability to amplify a humans power
Telecherics:
Either hydraulic or servo
motor actuators
Closed loop by human
operator
Especially useful in
dealing with hazardous
substance such as
radioactive waste

Locomotive mechanisms:
That imitate human beings
or animals by having the
ability to walk on two or four
legs.
Human operator is
required to execute the
locomotive process
Why Use Robots?
• Consistent performance in repetitive boring tasks, such as
machine loading and inspection
• Hazardous or uncomfortable environments, such as those
associated with spray painting, arc welding, grinding,
deep sea diving, radioactive materials handling

 Cost reduction and increased productivity

– robots can work up to 10 times faster than people in repetitive low-
skill tasks, such as spot welding, drilling and reviting
– in general, robots work at about the same rate as a person, but cost
about 50% as much as a person per hour
– robots can work 24 hrs/day, do not take breaks or sick leave
The benefits(advantages) of application of robots in manufacturing
industries can be listed as follows :

1) Flexibility – essential for automation of

batch production.
2)Reduced change over time and cost – needed
for mixed products on high volume lines.
3) Better quality.
4) Consistency in production rate and quality.
5) Increased productivity rate and quality.
6) Reduced lead time and capital cost.
7) Increased morale of the workers.
8)Reduction in overall manufacturing cost/price or
unit.
 The major conditions justifiable for robot application in the
industries essentially are :

a) Dull for repetition, monotony and fatigue.

b) Difficult for arduousness and complexity of work and
desired precision and
consistency.
c) Dirty – nonworkable for human being.
d) Dangerous – hazardous for chemicals, gas, heat,
noise, electricity, radio-activity etc. unsafe- underwater,
space, mines.
a) Industry –
I) Material handling applications
ii) Processing operations
iii) Assembly operations
iv) Inspection operation
i)Material Handling application.

 Equipped with right type of gripper or end effectors

for various applications like Part placement
 Pick up part from one location and place at new
location.
 Basic application –pick and place. Ex. Transferring
parts from one conveyor to another.
 ii) Palletizing & depalletising
 Palletizing : stacking parts on one on top of
the other.
 Ex. Taking parts from an assembly line and
stacking them on a palette.
 Depalletising: opposite of Palletizing
 Ex. Taking parts from a palette and placing
them on an assembly line.
 iii) Material handling
• The simple task of moving a
part or object from one
location to another within the
work area in one of the most
common applications for
robots today. (palletization &
depalletization).
• Other important parts-
handling applications involve
the acquiring of blank or
unfinished parts and feeding
them into some type of
machine tool for finishing.
iv) Machine loading and unloading

 Machine loading :press working operation.

 Machine unloading :bin picking,die casting,
plastic molding.
 Machine loading and unloading:machining
operation,heat treatment,forging.
 Insertion operations:
 v) Processing operations
 Robot performs a processing operation on the
part. EX.
 Spot welding
 Continuous arc welding
 Spray painting
 Metal cutting and deburring operations
 Drilling,grinding,laser and water jet cutting.
Riveting.
 Adhesive and sealant dispensing.
Welding

 The most popular applications of robots are in industrial

welding.
 The repeatability, uniformity quality, and speed of robotic
welding are unmatched.
 The two basic types of welding tasks performed by robots are
spot welding and arc welding, although laser welding is done.
 Another major welding task performed by robots is seam
welding
 Painting

 Another popular and efficient use for robots is in the field of spray
painting.
 The consistency and repeatability of a robot’s motion have enabled
neat perfect quality while at the same time wasting no paint
 The spray painting done relieve humans from a hazardous, though
skillful job, while at the same time increasing work quality, uniformity,
and cutting costs.
 Painting robots have 2 special features the capability of moving the
painting head over a complex surface at a constant velocity relative to
that surface, and a non spark emitting safety feature.
 Assembly operations
 Assembly operations represents an attractive
application of robots because these jobs may be
extremely tedious because of their repetitive nature.

 E.g. Assembly of printed circuit

boards. Extremely accurate
placement before insertion of
transistors & chips is usually
required.
 Robots can also be used to
assemble several parts of an
automobile.
Geometrical configuration.
 1.Cartesian
1.Cartesianrobot
robot

• Arm moves in 3 linear axes. x,y,z axes

Cartesian
Cartesian
Cartesian Robot: 3P
3P
1.Cartesian/rectangular

Three Linear axis of motion.

(3P)Left-right
Forward –backward
Up-down(z)
Work envelope
Is rectangular.
 Advantages

1. Linear movements allow for simple controls

2. High degree of mechanical rigidity ,accuracy
and repeatability
3. They can carry heavy loads because the
weight –lifting capacity does not vary at
different locations in work envelope.
(Independent of gravity loading)
4. Resolution-smallest possible increment
same for all axis.
 Disadvantages
1. Large structural framework.
2. More complex mechanical design for linear
sliding motions.
3.Movement is limited to one direction at a time.
4.Can only reach in front
of itself
Applications

1. Pick and place operation

2. Adhesive applications(mostly long and straight)
3. Assembly and sub assembly(mostly straight)
4. Inspection
5. Nuclear material handling
6. General machining and loading operation.
7. Water jet cutting.
2.Cylindrical coordinates robot

Arm rotates about the base, moves in and out, and up and
down
Cylindrical coordinate
 Cylindrical coordinate
 A cylindrical or post type co-ordinate robot has two linear
motion and one rotary motion.
 Radial motion ®
 The first co ordinate
describes the angle θ
of base rotation.
 Up-down(Z)
 Work volume is
 cylindrical.
 Reach and height
 axis rigid
 Base resolution in
degrees
• Advantages
1.Two linear axes make the mechanical design less
complex than the Cartesian robots.
2.vertical structure conserves space
3.Can reach all-round itself

• Disadvantages
1.Cannot reach above itself.
2.Horizontal motion is circular.
3.Won,t reach around obstacles.
4.Base rotation axis is less rigid.
5.Repeatability and accuracy are lower due to rotary joint.
3. Polar/Spherical Robot
Arm rotates about the base, moves in and out, and up and
down
Spherical or polar robots
Spherical or polar robots

A spherical co-ordinate robot has one linear

motion and two rotary motion.
 I.e(2R-1P)
 The first co ordinate describes the angle θ of
base rotation.
 The second co ordinate describes the angle
Ø of elbow.
 Radial motion ®
 Advantages
1. Design is simple and gives good weight lifting
capabilities.
2. Long horizontal reach.
3. Configuration suited for applications where small
amount of vertical movement is adequate.
Disadvantages.
1. Short vertical reach
2. Less stability
3. Can’t reach around obstacles.
4. Repeatability and accuracy are lower due to rotary
joints.
Application
1. Press loading
2. Dip coating
3. Stacking and unstacking
4. Part cleaning
5. Heat treatment
6. Forging.
4.Joined-arm or revolute-coordinates robot
 3 axes rotational
Also called articulated robot

 Most anthromorphic or
human like robot.
 i.e design is similar to human
arm.
 Rotation about base-
waist(vertical axis)
 Shoulder(horizontal)
 Elbow. (horizontal)
 Work envelope is circular
when viewed from top.
 From side ,the envelope has circular outer
surface and scalloped inner surface.

Advantages
1. Can reach around obstacles.
2. Large work area for least floor space.
Disadvantages
1. Less accuracy due to rotary joints.
2. Sophisticated controller because programming
is complex.
3. Less stable especially at maximum reach.
BASIC COMPONENTS OF ROBOT

Motion power unit Elbow Arm

2 3

6
4
1
Control unit
Shoulder Wrist

6 Revolute joints
= 6R robot Manipulator
 1. Manipulator
 The manipulator is a
mechanical unit that
provides motion similar to
human arm.
 The manipulator consists of
a series of rigid
members ,called links and
are connected at joints
 Its primary function is to
provide the specific motion
that will enable the tooling
at the end to do the
required work
 The motion of joints are accomplished by actuator
 The manipulator bends, slides ,or rotates about
these joints which as referred to as degrees of
freedom.
 The manipulator itself may be thought of as being
composed of three divisions
1. The major linkages.(Positioning)
2. The minor linkages(wrist components-orientation)
3. The end effector.
 The Minor Linkages
(wrist Assembly-orientation)

 The wrist movement is

designed to orient the end
effector properly.
 Normally wrist is provided
with 3 DOF.
 A typical wrist is shown
 The DOF are
1. Wrist roll
2. Wrist pitch
3. Wrist Yaw.
1. Wrist roll:-This involves rotation of
mechanism about the arm axis. Also called as
wrist swivel.
2. Wrist pitch:-Given the wrist roll is in its center
position ,the pitch would involve the up or
down rotation of the wrist. It is sometimes
called wrist bend.
3. Wrist yaw :-Given the wrist roll is in its center
position ,the pitch would involve the right or
left rotation of the wrist.
 End-effector's: Grippers and tools
The device which is attached to the wrist of a robot to
enable it work by basically gripping and releasing parts or
tools is called end-effector or simply robot hand.
These, special purpose fixture like attachments are custom
engineered and procured separately by :
1) placing special order to the robot manufacturer/supplier if
they have such provision.
2) design, and build in the users’ side
3) buy standard device from market and adopt it to
requirement
4) get it by contract or consultancy.
 End Effector (Gripper):

Standard hand Self-aligning fingers Round object finger Cam-operated hand

Finger action Secure grip Grips different sizes Lifts heavy objects
Force multiplication No object ‘cocking’ or different shapes Narrow size range

Spot
Arc welding
Pouring
welding gun
ladle
torch