1. Teaching Innovation - Entrepreneurial - Global
DTEL(Department for Technology Enhanced Learning)
The Centre for Technology enabled Teaching & Learning , N Y S S, India
Teaching Innovation - Entrepreneurial - Global

2. DEPARTMENT OF mechanical engineering
viii-semester
Automation in production
CHAPTER NO.3
INDUSTRIAL ROBOTICS

3. CHAPTER 3:- SYLLABUS . 1
Industrial Robotics:- Introduction robot anatomy robot
Robot control systems & other specifications 2
Introduction to End effectors, Sensors, robot
programming , safety monitoring. 3 4
Robot application -Characteristic of robot applications 5
Work cell layout, robot applications in material, handling,
processing, assembly and inspection.
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4. CHAPTER-1 SPECIFIC Objective / course outcome
The student will be able to:
Understand Industrial Robotics and Robot System. 1
Know the different features & programming languages
& it’s applications . 2
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5. Introduction LECTURE 1:- ROBOTICS
A general-purpose, programmable machine possessing certain anthropomorphic characteristics
Hazardous work environments
Repetitive work cycle
Consistency and accuracy
Difficult handling task for humans
Multishift operations
Reprogrammable, flexible
Interfaced to other computer systems 5
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6. Robot Anatomy LECTURE 1:- ROBOTICS
Base
Link0
Joint1
Link2
Link3
Joint3
End of Arm
Link1
Joint2
Manipulator consists of joints and links
Joints provide relative motion
Links are rigid members between joints
Various joint types: linear and rotary
Each joint provides a “degree-of-freedom”
Most robots possess five or six degrees-of-freedom
Robot manipulator consists of two sections:
Body-and-arm – for positioning of objects in the robot's work volume
Wrist assembly – for orientation of objects 6
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7. Manipulator Joints LECTURE 1:- ROBOTICS Translational motion
Linear joint (type L)
Orthogonal joint (type O)
Rotary motion
Rotational joint (type R)
Twisting joint (type T)
Revolving joint (type V) 7
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8. Joint Notation Scheme LECTURE 1:- ROBOTICS
Uses the joint symbols (L, O, R, T, V) to designate joint types used to construct robot manipulator
Separates body-and-arm assembly from wrist assembly using a colon (:)
Example: TLR : TR
Common body-and-arm configurations … 8
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9. Polar Coordinate Body-and-Arm Assembly
LECTURE 1:- ROBOTICS
Polar Coordinate Body-and-Arm Assembly
Notation TRL:
Consists of a sliding arm (L joint) actuated relative to the body, which can rotate about both a vertical axis (T joint) and horizontal axis (R joint) 9
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10. Cylindrical Body-and-Arm Assembly
LECTURE 1:- ROBOTICS
Cylindrical Body-and-Arm Assembly
Notation TLO:
Consists of a vertical column, relative to which
an arm assembly is moved up or down
The arm can be moved in or out relative to the
column 10
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11. Cartesian Coordinate Body-and-Arm Assembly
LECTURE 1:- ROBOTICS
Cartesian Coordinate Body-and-Arm Assembly
Notation LOO:
Consists of three sliding joints, two of which are orthogonal
Other names include rectilinear robot and x-y-z robot 11
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12. LECTURE 1:- ROBOTICS
Jointed-Arm Robot
Notation TRR: 12
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13. SCARA Robot LECTURE 1:- ROBOTICS Notation VRO
SCARA stands for Selectively Compliant Assembly Robot Arm
Similar to jointed-arm robot except that vertical axes are used for shoulder and elbow joints to be compliant in horizontal direction for vertical insertion tasks 13
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14. Wrist Configurations LECTURE 1:- ROBOTICS
Wrist assembly is attached to end-of-arm
End effectors is attached to wrist assembly
Function of wrist assembly is to orient end effector
Body-and-arm determines global position of end effectors
Two or three degrees of
freedom:
Roll involves rotating
the wrist about the arm
axis
Pitch up-down rotation of the wrist
Yaw left-right rotation
of the wrist
End effector is mounted on
the wrist
Notation :RRT 14
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15. Example LECTURE 1:- ROBOTICS
Sketch following manipulator configurations
TRT:R, (b) TVR:TR, (c) RR:T.
Solution: 15
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16. Joint Drive Systems LECTURE 2:- ROBOTICS Electric
Uses electric motors to actuate individual joints
Preferred drive system in today's robots
Hydraulic
Uses hydraulic pistons and rotary vane actuators
Noted for their high power and lift capacity
Pneumatic
Typically limited to smaller robots and simple material transfer applications 16
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17. Robot Control Systems LECTURE 2:- ROBOTICS
Limited sequence control – pick-and-place operations using mechanical stops to set positions
Playback with point-to-point control – records work cycle as a sequence of points, then plays back the sequence during program execution
Playback with continuous path control – greater memory capacity and/or interpolation capability to execute paths (in addition to points)
Intelligent control – exhibits behavior that makes it seem intelligent, e.g., responds to sensor inputs, makes decisions, communicates with humans 17
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18. LECTURE 2:- ROBOTICS
Robot Control System 18
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19. End Effectors LECTURE 2:- ROBOTICS
The special tooling for a robot that enables it to perform a specific task
Two types:
Grippers – to grasp and manipulate objects (e.g., parts) during work cycle
Tools – to perform a process, e.g., spot welding, spray painting 19
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20. LECTURE 2:- ROBOTICS
Grippers and Tools 20
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21. Using Piezoelectric Effect
LECTURE 2:- ROBOTICS
Sensors
Human senses: sight, sound, touch, taste, and smell provide us vital information to function and survive
Robot sensors: measure robot configuration/condition and its environment and send such information to robot controller as electronic signals (e.g., arm position, presence of toxic gas)
Robots often need information that is beyond 5 human senses (e.g., ability to: see in the dark, detect tiny amounts of invisible radiation, measure movement that is too small or fast for the human eye to see)
Accelerometer
Using Piezoelectric Effect 21
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22. Sensors LECTURE 2:- ROBOTICS
Force Sensor: e.g., parts fitting and insertion, force feedback in robotic surgery
Parts fitting and insertion: Robots can do precise fitting and insertion of machine parts by using force sensor. A robot can insert parts that have the phases after matching their phases in addition to simply inserting them. It can automate high-skill jobs. 22
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23. Sensors LECTURE 2:- ROBOTICS
Internal sensors to measure the robot configuration
Encoders measure the rotation angle of a joint
Limit switches detect when the joint has reached the limit 23
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24. Sensors LECTURE 2:- ROBOTICS
Proximity sensors are used to measure the distance or location of objects in the environment. This can then be used to determine the location of the robot.
Infrared sensors determine the distance to an object by measuring the amount of infrared light the object reflects back to the robot
Ultrasonic sensors (sonars) measure the time that an ultrasonic signal takes until it returns to the robot
Laser range finders determine distance by
measuring either the time it takes for a laser
beam to be reflected back to the robot or by
measuring where the laser hits the object 24
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25. Sensors LECTURE 2:- ROBOTICS
Computer Vision provides robots with the capability to passively observe the environment
Stereo vision systems provide complete location information using triangulation
However, computer vision is very complex
Correspondence problem makes stereo vision even more difficult 25
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26. Work Envelope concept LECTURE 2:- ROBOTICS
Depending on the configuration and size of the links and wrist joints, robots can reach a collection of points called a Workspace.
Alternately Workspace may be found empirically, by moving each joint through its range of motions and combining all space it can reach and subtracting what space it cannot reach 26
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27. LECTURE 2:- ROBOTICS
Working Envelope 27
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28. Reference Frames LECTURE 2 :- ROBOTICS
World Reference Frame which is a universal coordinate frame, as defined by the x-y-z axes. In this case the joints of the robot move simultaneously so as to create motions along the three major axes.
Joint Reference Frame which is used to specify movements of each individual joint of the Robot. In this case each joint may be accessed individually and thus only one joint moves at a time.
Tool Reference Frame which specifies the movements of the Robots hand relative to the frame attached to the hand. The x’,y’and z’ axes attached to the hand define the motions of the hand relative to this local frame. All joints of the Robot move simultaneously to create coordinated motions about the Tool frame. 28
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29. Robot Reference Frames
LECTURE 2:- ROBOTICS
Robot Reference Frames 29
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30. Control Methods LECTURE 3:- ROBOTICS Non Servo Control
Implemented by setting limits or mechanical stops for each joint and sequencing the actuation of each joint to accomplish the cycle
End point robot, limited sequence robot, bang-bang robot
No control over the motion at the intermediate points, only end points are known
Programming accomplished by
Setting desired sequence of moves
Adjusting end stops for each axis accordingly
The sequence of moves is controlled by a “squencer”, which uses feedback received from the end stops to index to next step in the program
Low cost and easy to maintain, reliable
Relatively high speed
Repeatability of up to 0.01 inch
Limited flexibility
Typically hydraulic, pneumatic drives 30
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31. Control Methods LECTURE 3:- ROBOTICS Point to point Control
Servo Control
Point to point Control
Continuous Path Control
Closed Loop control used to monitor position, velocity (other variables) of each joint 31
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32. Point-to-Point Control
LECTURE 4:- ROBOTICS
Point-to-Point Control
Only the end points are programmed, the path used to connect the end points are computed by the controller
User can control velocity, and may permit linear or piece wise linear motion
Feedback control is used during motion to ascertain that individual joints have achieved desired location
Often used hydraulic drives, recent trend towards servomotors
loads up to 500lb and large reach
Applications
pick and place type operations
palletizing
machine loading 32
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33. Continuous Path Controlled
LECTURE 4:- ROBOTICS
Continuous Path Controlled
In addition to the control over the endpoints, the path taken by the end effector can be controlled
Path is controlled by manipulating the joints throughout the entire motion, via closed loop control
Applications:
spray painting
Polishing
Grinding
arc welding 33
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34. Robot Programming LECTURE 4:- ROBOTICS Leadthrough programming
Work cycle is taught to robot by moving the manipulator through the required motion cycle and simultaneously entering the program into controller memory for later playback
Robot programming languages
Textual programming language to enter commands into robot controller
Simulation and off-line programming
Program is prepared at a remote computer terminal and downloaded to robot controller for execution without need for leadthrough methods 34
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35. Use of Teach Pendant LECTURE 4:- ROBOTICS
Hand held device with switches used to control the robot motions
End points are recorded in controller memory
Sequentially played back to execute robot actions
Trajectory determined by robot controller
Suited for point to point control applications
Easy to use, no special programming skills required
Useful when programming robots for wide range of repetitive tasks for long production runs
RAPID 35
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36. Lead Through Programming
LECTURE 5:- ROBOTICS
Lead Through Programming
Powered leadthrough
Common for point-to-point robots
Uses teach pendant
Manual leadthrough
Convenient for continuous path control robots
Human programmer physical moves manipulator
Lead the robot physically through the required sequence of motions
Trajectory and endpoints are recorded, using a sampling routine which records points at times a second
When played back results in a smooth continuous motion
Large memory requirements 36
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37. Leadthrough Programming Advantages
LECTURE 5:- ROBOTICS
Leadthrough Programming Advantages
Advantages:
Easily learned by shop personnel
Logical way to teach a robot
No computer programming
Disadvantages:
Downtime during programming
Limited programming logic capability
Not compatible with supervisory control 37
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38. Robot Programming LECTURE 5:- ROBOTICS Textural programming languages
Enhanced sensor capabilities
Improved output capabilities to control external equipment
Program logic
Computations and data processing
Communications with supervisory computers 38
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39. Coordinate Systems LECTURE 5:- ROBOTICS
World coordinate system Tool coordinate system 39
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40. Programming Languages
LECTURE 6:- ROBOTICS
Programming Languages
Motivation
need to interface robot control system to external sensors, to provide “real time” changes based on sensory equipment
computing based on geometry of environment
ability to interface with CAD/CAM systems
meaningful task descriptions
off-line programming capability
Large number of robot languages available
AML, VAL, AL, RAIL, RobotStudio, etc. (200+)
Each robot manufacturer has their own robot programming language
No standards exist
Portability of programs virtually non-existent 40
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41. Motion Commands LECTURE 6:- ROBOTICS MOVE P1
HERE P1 - used during lead through of manipulator
MOVES P1
DMOVE(4, 125)
APPROACH P1, 40 MM
DEPART 40 MM
DEFINE PATH123 = PATH(P1, P2, P3)
MOVE PATH123
SPEED 75 41
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42. Interlock and Sensor Commands
LECTURE 6:- ROBOTICS
Interlock and Sensor Commands
Interlock Commands
WAIT 20, ON
SIGNAL 10, ON
SIGNAL 10, 6.0
REACT 25, SAFESTOP
Gripper Commands
OPEN
CLOSE
CLOSE 25 MM
CLOSE 2.0 N 42
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43. Robot Applications LECTURE 6:- ROBOTICS
Need to replace human labor by robots:
Work environment hazardous for human beings
Repetitive tasks
Boring and unpleasant tasks
Multishift operations
Infrequent changeovers
Performing at a steady pace
Operating for long hours without rest
Responding in automated operations
Minimizing variation 43
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44. Industrial Applications
LECTURE 6:- ROBOTICS
Industrial Applications
Industrial Robot Applications can be divided into:
Material-handling applications:
Involve the movement of material or parts from one location to another.
It include part placement, palletizing and/or depalletizing, machine loading and unloading.
Processing Operations:
Requires the robot to manipulate a special process tool as the end effector.
The application include spot welding, arc welding, riveting, spray painting, machining, metal cutting, deburring, polishing.
Assembly Applications:
Involve part-handling manipulations of a special tools and other automatic tasks and operations.
Inspection Operations:
Require the robot to position a workpart to an inspection device.
Involve the robot to manipulate a device or sensor to perform the inspection. 44
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45. Material Handling Applications
LECTURE 7:- ROBOTICS
Material Handling Applications
This category includes the following:
Part Placement
Palletizing and/or depalletizing
Machine loading and/or unloading
Stacking and insertion operations
The robot must have following features to facilitate material handling:
The manipulator must be able to lift the parts safely.
The robot must have the reach needed.
The robot must have cylindrical coordinate type.
The robot’s controller must have a large enough memory to store all the programmed points so that the robot can move from one location to another.
The robot must have the speed necessary for meeting the transfer cycle of the operation. 45
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46. Material Handling Applications
LECTURE 7:- ROBOTICS
Material Handling Applications
Part Placement:
The basic operation in this category is the relatively simple pick-and-place operation.
This application needs a low-technology robot of the cylindrical coordinate type.
Only two, three, or four joints are required for most of the applications.
Pneumatically powered robots are often utilized.
Palletizing and/or Depalletizing
The applications require robot to stack parts one on top of the other, that is to palletize them, or to unstack parts by removing from the top one by one, that is depalletize them.
Example: process of taking parts from the assembly line and stacking them on a pallet or vice versa. 46
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47. Material Handling Applications
LECTURE 7:- ROBOTICS
Material Handling Applications
Machine loading and/or unloading:
Robot transfers parts into and/or from a production machine.
There are three possible cases:
Machine loading in which the robot loads parts into a production machine, but the parts are unloaded by some other means.
Example: a pressworking operation, where the robot feeds sheet blanks into the press, but the finished parts drop out of the press by gravity.
Machine loading in which the raw materials are fed into the machine without robot assistance. The robot unloads the part from the machine assisted by vision or no vision.
Example: bin picking, die casting, and plastic moulding.
Machine loading and unloading that involves both loading and unloading of the workparts by the robot. The robot loads a raw work part into the process ad unloads a finished part.
Example: Machine operation
Difficulties
Difference in cycle time between the robot and the production machine. The cycle time of the machine may be relatively long compared to the robot’s cycle time. 47
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48. Material Handling Applications
LECTURE 7:- ROBOTICS
Material Handling Applications
Stacking and insertion operation:
In the stacking process the robot places flat parts on top of each other, where the vertical location of the drop-off position is continuously changing with cycle time.
In the insertion process robot inserts parts into the compartments of a divided carton. 48
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49. Processing Operations
LECTURE 7:- ROBOTICS
Processing Operations
Processing Operations:
Robot performs a processing procedure on the part.
The robot is equipped with some type of process tooling as its end effector.
Manipulates the tooling relative to the working part during the cycle.
Industrial robot applications in the processing operations include:
Spot welding
Continuous arc welding
Spray painting
Metal cutting and deburring operations
Various machining operations like drilling, grinding, laser and waterjet cutting, and riveting.
Rotating and spindle operations
Adhesives and sealant dispensing 49
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50. Assembly Operations LECTURE 7:- ROBOTICS Assembly Operations:
The applications involve both material-handling and the manipulation of a tool.
They typically include components to build the product and to perform material handling operations.
Are traditionally labor-intensive activities in industry and are highly repetitive and boring. Hence are logical candidates for robotic applications.
These are classified as:
Batch assembly: As many as one million products might be assembled. The assembly operation has long production runs.
Low-volume: In this a sample run of ten thousand or less products might be made.
The assembly robot cell should be a modular cell.
One of the well suited area for robotics assembly is the insertion of odd electronic components.
Figure illustrates a typical overall electronic assembly operation. 50
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51. Inspection Operations
LECTURE 7:- ROBOTICS
Inspection Operations
Inspection Operation:
Some inspection operation require parts to be manipulated, and other applications require that an inspection tool be manipulated.
Inspection work requires high precision and patience, and human judgment is often needed to determine whether a product is within quality specifications or not.
Inspection tasks that are performed by industrial robots can usually be divided into the following three techniques:
By using a feeler gauge or a linear displacement transducer known as a linear variable differential transformer(LVDT), the part being measured will come in physical contact with the instrument or by means of air pressure, which will cause it to ride above the surface being measured.
By utilizing robotic vision, matrix video cameras are used to obtain an image of the area of interest, which is digitized and compared to a similar image with specified tolerance.
By involving the use of optics and light, usually a laser or infrared source is used to illustrate the area of interest. 51
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52. Inspection Operations
LECTURE 7:- ROBOTICS
Inspection Operations
The robot may be in active or passive role.
In active role robot is responsible for determining whether the part is good or bad.
In the passive role the robot feeds a gauging station with the part. While the gauging station is determining whether the part meets the specification, the robot waits for the process to finish. 52
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53. Assembly Operations LECTURE 7:- ROBOTICS DTEL Assembly Operations:
The applications involve both material-handling and the manipulation of a tool.
They typically include components to build the product and to perform material handling operations.
Are traditionally labor-intensive activities in industry and are highly repetitive and boring. Hence are logical candidates for robotic applications. 53
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54. THANK YOU
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