Robotics

1. CAD/CAM AND AUTOMATION
UNIT:6
ROBOTICS AND AUTOMATION

2. INTODUCTION
ROBOT
• Robots are devices that are programmed to
move parts, or to do work with a tool.
• Defined by Robotics Industry Association (RIA) as
– a re-programmable, multifunctional manipulator designed
to move material, parts, tools or specialized devices
through variable programmed motion for a variety of
tasks.

3. ROBOT ANATOMY

4. Main Parts of a Robot
• Control System
• Sensors
• Actuators
• Power Supply
• End Effectors

5. Types of joints
(a) Linear joint (type L joint) , (b) orthogonal joint (type O joint ) (c) Rotational joint
(type R joint ) (d) Twisting joint ( type T joint) (e) revolving joint (type V joint)

6. Robot Physical Configuration
Four basic configurations are
1. Cartesian configuration
2. Cylindrical configuration
3. Polar configuration
4. Jointed-arm configuration

7. Workspace
• Depending on the configuration and size of
the links and wrist joints, robots can reach a
collection of points called a Workspace.

8. Cartesian configuration
Work space: rectangular/cube

9. Cylindrical configuration
Work space: cylinder

10. Polar configuration
Work space: spherical

11. Jointed-arm configuration
Work space: like human arm

12. Basic Robot Motions
Six basic motions or degrees of freedom
• Three arm and body motions and
• Three wrist motions

13. Basic Robot Motions
Arm and body motions
1. Vertical traverse: Up and down motion of the arm, caused by
pivoting the entire arm about a horizontal axis or moving the arm
along a vertical slide.
2. Radial traverse: extension and retraction of the arm (in and out
movement)
3. Rotational traverse: rotation about the vertical axis (right or left
swivel of the robot arm)
Wrist Motion
4. Wrist swivel: Rotation of the wrist
5. Wrist bend: Up or down movement of the wrist, this also involves
rotation movement.
6. Wrist yaw: Right or left swivel of the wrist.

14. Motion system
• Point-to-point (PTP) control robot
• Continuous-path (CP) control robot

15. Point-to-point (PTP) control robot
• Capable of moving from one point to another
point
• Do not control the path to get from one point
to the next point.
• Application:
component insertion, spot welding, hole
drilling, machine loading and unloading

16. Continuous-path (CP) control robot
• Robot can stop at any specified point along
the controlled path.
• All the points along the path must be stored
in the robot’s control memory. Typical
Applications:
spray painting, finishing, gluing, and arc
welding operations.

17. Types Of Drive Systems
• There are three basic drive system used in
commercially available robots:
1. Hydraulic drive
2. Electric drive
3. Pneumatic drive

18. Cont..
1. Hydraulic drive:
• Gives a robot great speed and strength.
• These systems can be designed to actuate
linear or rotational joints.
• It occupies floor space in addition to that
required by the robot.

19. Cont...
2. Electric drive
• Compared with a hydraulic system, an electric
system provides a robot with less speed and
strength.
• Adopted for smaller robots.
• More accurate, exhibit better repeatability,
and are cleaner to use.

20. Cont..
3. Pneumatic drive
• Used for smaller robots.
• Suitable for simple pick-and-place material
handling operations.

21. End Effectors
• In the terminology of robotics, end effectors
can be defined as a device which is attached
to the robots wrist to perform a specific task.
• The end effectors are the special purpose
tooling which enables the robot to perform a
particular job
• End effectors have two categories:
grippers and tools.

22. Grippers
• are generally used to grasp and hold an object
and place it at a desired location.
Grippers can be classified as
• Mechanical grippers
• Vacuum or suction cups
• Magnetic grippers
• Adhesive grippers
• Hooks,
• Scoops, and so forth.

23. Cont..

24. Cont..

25. Tools
• A robot is required to manipulate a tool to
perform an operation on a work part. Here the
tool acts as end-effectors.
• Spot-welding tools, arc-welding tools, spray
painting nozzles, and rotating spindles for
drilling and grinding are typical examples of
tools used as end-effectors.

26. ROBOT APPLICATIONS
Need to replace human labour by robots:
• Work environment hazardous for human beings
• Repetitive tasks
• Boring and unpleasant tasks
• Multi shift operations
• Infrequent changeovers
• Operating for long hours without rest
• Responding in automated operations

27. Industrial Robot Applications
• Material-handling applications
• Processing Operations
• Assembly Applications
• Inspection Operations

28. Advantages of Robots
• Robotics and automation can, in many situation, increase productivity,
safety,
efficiency, quality, and consistency of Products
• Robots can work in hazardous environments
• Robots need no environmental comfort
• Robots work continuously without any humanity needs and illnesses
• Robots have repeatable precision at all times
• Robots can be much more accurate than humans, they may have milli or
micro inch
accuracy.
• Robots and their sensors can have capabilities beyond that of humans.
• Robots can process multiple stimuli or tasks simultaneously, humans can
only one.
• Robots replace human workers who can create economic problems.

29. Disadvantages of Robots
• Robots lack capability to respond in emergencies, this can cause:
Inappropriate and wrong responses
A lack of decision-making power
A loss of power
Damage to the robot and other devices
Human injuries
• Robots may have limited capabilities in
Degrees of Freedom
Sensors
Vision systems
Real-time Response
• Robots are costly, due to
Initial cost of equipment
Installation Costs
Need for training
Need for Programming