BEE4393 (Automation and Robotics)

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BEE4393 (Automation
and Robotics)
Cik Mahfuzah Mustafa
room no :A1-02-07
ext: 2323
Contents
History of Robotics
 Robotics Application
 Social and Economic Issues
 Robot anatomy and Work Volume
 Robot Configuration and work Space
 End-effectors: Grippers and Tools
 Robot Actuators and Drive Systems
 Safety Consideration

Who introduced the word robot?
o
o
The term robot was first introduced by a Czech
dramatist, Karel Capek in his 1921 play
"Rossum's Universal Robots". He was referring
to a perfect and tireless worker performing
manual labour jobs for human beings.
Isaac Asimov, coined the word robotics as the
science of the study of robots, in his science
fiction stories about robots in 1940s.
Definition
Robot term from Webster’s dictionary:- An
automatic device that performs function
ordinarily ascribed to human being
 'Automation' refers to a mode of operation
in which any machine or piece of
equipment is capable of working without
human intervention.

Automation is generally regarded as being
able to be divided into 2 types:
1.
2.
Fixed automation
Flexible automation
Fixed automation


Used when the volume of production is very high
and it is, therefore, appropriate to design
specialized equipment to process products at
high rates and low cost
Eg: automobile industry, where highly integrated
transfer line are used to perform machine
operation on engine and transmission
components
Flexible automation


Most suitable for the mid-volume production
range. Typically consists of a series of
workstation that are interconnected by materialhandling and storage equipment to process
different product configuration at the same time
to control manufacturing system
Eg: Flexible Manufacturing System (FMS),
Computer Integrated Manufacturing (CIM)
History of Robotics
Date
Development
mid- 1 700s
J. de Vaucanson built several human-sized
mechanical dolls that played music.
1971
The -Stanford Arm," a small electrically powered robot
arm, developed at Stanford University.
1979
Development of S.CARA type robot (Selective
Compliance Arm for Robotic Assembly) at Yamanashi
University in Japan for assembly. Several commercial
SCARA robots introduced around 1981
Social and Economic Issues





In the social area, what are the main issues related to robotics? How
will the labour and manpower market be affected by robotics? How
many workers are likely to be displaced?
What are the impacts on the professional and semiprofessional work
force who are employed in manufacturing? Also, will robotics affect
productivity and international economic competition?
What kind of retraining and education is needed to upgrade the
present work force?
Will foreign investors still choose Malaysia (as cheap labour will not
be needed when factories are run by robots)?
Some 90 percent of Malaysian industry is in the SMI (Small and
Medium Industry) category. Can SMIs afford installation of robotics
in the near future? Or will robotics benefit only MNCs (Multinational
Corporations)?
Robot anatomy and Work Volume
Robot anatomy deals with:
 the types and sizes of these joints and
links
 and other aspects of the manipulator’s
physical construction
What is a joint?



A joint of robot is
similar to a joint in the
human body
Each joint gives the
robot with a degreeof-freedom(d.o.f)of
motion
In the nearly all
cases, only 1 d.o.f is
allowed to a joint
Joint
What is a robot link?


Links are rigid
components that form
a chain connected
together by joints
Each joint has two
links, known as an
input link and an
output link
Link
Types of robot joints
1.
2.
3.
4.
5.
Linear joint
Orthogonal joint
Rotational joint
Twisting joint
Revolving joint
Linear joint
The relative movement
between the input link
and the output link is a
linear sliding motion,
with the axes of the two
links being parallel
Orthogonal joint
This is also linear
sliding motion, but the
input and output links
are perpendicular to
each other during the
move
Rotational joint
This type provides a
rotational relative
motion of the joints, with
the axis of rotation
perpendicular to the
axes of the input and
output links
Twisting joint
This joint also involves
a rotary motion, but the
axis of rotation is
parallel to the axes of
the two links
Revolving joint
In this types, the axis of
the input link is parallel
to the axis of rotation of
the joint, and the axis of
the output link is
perpendicular to the
axis of rotation
This joint-link numbering, scheme
is shown below.
GENERAL CLASIFICATION OF
ROBOTS
o
o
o
Low technology
Medium technology
High technology
Low technology
 Material
handling, using simple assembly
 2 to 4 axes of movement
 Stop at extreme
Medium technology
Pick-and-place
 Material handling
 4 to 6 axes

High technology
Material handling
 Pick-and-place
 Loading and unloading
 Painting and welding
 6 to 9 axes

Robot Classification Based On
Kinematic Structure
Normally, robot manipulators are classified
according to their arm geometry or kinematic
structure. The majority of these manipulators fall
into one of these five configuration:
1.
2.
3.
4.
5.
Cartesian Type Configuration (PPP)
Cylindrical Type Configuration (RPP)
Spherical Type Configuration (RRP)
SCARA Type Configuration (RRP or PRR)
Revolute Type Configuration (RRR)
Cartesian Type Configuration
(PPP)
Cartesian Type Configuration
(PPP)

Manipulator whose first three joints are prismatic are known as a Cartesian
manipulator.. Cartesian manipulator are useful for table-top assembly
applications and, as gantry robots for transfer of material and cargo

Advantages:
- 3 linear axes
- Easy to visualize
- Rigid structure
- Easy to program off-line
- Linear axes make for easy mechanical stops
Disadvantage:
- Can only reach in front of itself
- Requires large floor space for size of work envelop
- Axes hard to seal

Cylindrical Type Configuration
(RPP)
Cylindrical Type Configuration
(RPP)



For cylindrical type manipulator, its first joint is revolute which produces a
rotation about the based, while its second and third joints are prismatic.
Advantages:
- 2 linear axes, 1 rotating axis
- Can reach all around itself
- Reach and height axes rigid
- Rotational axis easy to seal.
Disadvantages:
- Cannot reach above itself
- Base rotation axis is less rigid than a linear axis
- Linear axes hard to seal
- Will not reach around obstacles
- Horizontal motion is circular
Spherical Type Configuration
(RRP)
Spherical Type Configuration
(RRP)
The first two joints of this type of manipulators
are revolute, while its third Joint is prismatic.
 Advantages:
- 1 linear axis, 2 rotating axes
- Long horizontal reach
 Disadvantages:
- Cannot reach around obstacles
- Generally has short vertical reach

SCARA Type Configuration (RRP
or PRR)
SCARA Type Configuration (RRP
or PRR)



The word SCARA stands for Selective Compliant Articulated Robot for
Assembly. There are two type of SCARA robot configuration: either the first
two joints are revolute with the third joint as prismatic, or the first joint is
revolute with the second and third Joints as prismatic.
Advantages:
- 1 linear axis, 2 rotating axes
- Height axis is rigid
- Large work area floor space
- Can reach around obstacles
- Two ways to reach a point
Disadvantages:
- Difficult to program off-line
- Highly complex arm
Revolute Type Configuration (RRR)
Revolute Type Configuration (RRR)



Revolute manipulator is also called articulated or anthromorphic
manipulator. These type of robot resembles human arm. Two
common revolute designs are the elbow type manipulator such as
the PUMA and the parallelogram linkage such as the Cincinnati
Milacron T3 735.
Advantages:
- 3 rotating, axes
- Can reach above or below obstacles
- Largest work area for least work space
- Two or four ways to reach a point
Disadvantages:
- Difficult to program off-line
- The most complex manipulator
Robot Actuators and Drive Systems
What is actuator?
The commonly used actuators are:
1. Stepper motors
2. DC servomotors
3. AC servomotors
4. Hydraulic pistons
5. Pneumatic pistons
Electric Drive


Small and medium size robots are usually
powered by electric drives via gear trains using
servomotors and stepper motors.
Advantages
- Better accuracy & repeatability
- Require less floor space
- More towards precise work such as assembly applications

Disadvantages
- Generally not as speedy and powerful as hydraulic robots
- Expensive for large and powerful robots, can become fire hazard
Hydraulic Drive
Larger robots make use of hydraulic
drives.
 Advantages:

- more strength-to-weight ratio
- can also actuate at a higher speed

Disadvantages:
- Requires more floor space
- Tendency to oil leakage.
Pneumatic Drive
 For
smaller robots that possess fewer
degrees of freedom (two- to fourjoint
motions).
 They are limited to pick-and-place tasks with
fast cycles.
Direct Drive Robots
 In
1981 a "direct- drive robot" was developed at
Carnegle-Mellon University, USA. Is used electric
motors located at the manipulator joints without the
usual mechanical transmission linkages used on most
robots.
 The drive motor is located contiguous to the joint.
 Benefits:



Eliminate backlash and mechanical defiencies
Eliminate the need of a power transmission (thus more
efficient)
Joint backdrivable (allowing for joint-space force sensing)
End-effectors: Grippers and Tools
What is gripper? What is tool?
 Mechanical grippers
 Vacuum systems
 Magnetic Pickups
 Tools
Cam-operated hand
It can easily handle heavy weights
or bulky objects. It is designed to
hold the object so that its center
of gravity (CG) is kept very closed
to the wrist of hand. The short
distance between the wrist and
the CG minimizes the twisting
tendency of a heavy or bulky
object.
Special hand with modular
gripper
This special hand, with
pair of pneumatic
actuators, is one of the
many special hand
designs for industrial
robots. It is suitable for
parts of light weight.
Special hand for glass tubes
This hand is specially
designed for industrial
robots to securely
grasping of relatively
short tubes.
Simple vacuum cup hand
This simple vacuum cup
hand is suitable for
Handling fragile parts
such as cathode ray
tube face plates
(Illustrated).
Magnetic Pick up
Magnetic handling is
most suitable for parts
of ferrous contents.
Magnets can be
scientifically designed and
made in numerous shapes
and sizes to perform various
tasks.
Ladle
Ladling hot materials such as
molten metal is a hot and
hazardous job for which
industrial robots are well suited.
In piston casting permanent mold
die casting and related
applications, the robot can be
programmed to scoop up and
transfer the molten metal from the
pot to the mold, and then do the
pouring.
Spray gun
Ability of the industrial robot to do
multipass spraying with controlled
velocity fits it for automated
application of primers, paints, and
ceramic or glass frits, as well as
application of masking agents used before
plating. For short or medium-length
production runs, the industrial robot would
often be a better choice than a special
purpose setup requiring a lengthy
change-over procedure for each different
part. Also the robot can spray parts with
compound curvatures and multiple
surfaces.
Tool changing
A single industrial robot can
also handle several tools
sequentially, with an
automatic tool-changing
operation programmed into
the robot's memory. The
tools can be of different
types or sizes, permitting
multiple operations an the
same workpiece
Safety Consideration
When?
 Practice it as soon as starting robotics
project
 Must be built into robotics system at the
outset
 Do not risk injuries by robots
What Dangers?
Repairing a robot
 Training/programming robot
 Normal operation
 Power supply

What sort of injuries?
Bodily impact
 Pinching-caught in grippers or joints
 Pining human against a structure

http://world.honda.com/HDTV/ASIMO/
for Asimo video
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