Robotics

Robotics

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Course objective 



To provide a broad understanding of the use of industrial robots And an experience in specifying, designing and presenting a new robot application in oral and written formats.

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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SYLLABUS TOPIC 1. Realistic and Safe Use of Robots 2. Applications of Industrial Robots Project 3. Economic Justification Excel Template 4. Robot Implementation 5. Arm Configurations Quiz 1 Take Home 6. Wrist Configurations 7. End Effectors and Tooling 8. Methods of Actuation 9. Non-servo Operation 10. Servo Controlled Robots 11. Cell Control, Hierarchical Design 12. Performance Measures Sample Report 1 - Welding Sample Report 2 - Painting Sample Report 3 - Soldering Sample Report 4 - Batch Manufacturing Sample Report 5 - Machine Loading 13. Joint Control Programming 14. Path Control Programming 15. High Level Languages 16. Simulation and Programming 17. Vision and Sensor Systems 18. Work Cell Interfacing; REPORT DUE 19. Intelligent Robot Cells 20. Flexible Manufacturing 21. FINAL ORAL EXAM 10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Objective 





Determine the relationship between various robot applications and the methods of actuation available on commercial robots or automated guided vehicles. Be able to select the appropriate method of actuation for a robot application. Be able to estimate the load force and moments to select the proper method of actuation.

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Methods of actuation 

1. Hydraulic Most powerful 2. Electric Most common 3. Pneumatic Lowers cost

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Common drive systems for positioning axes 

Linear motion  

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Rack and pinion Piston and cylinder

Rotary motion   

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10/19/2015

Rotary hydraulic actuator A.C. or D.C. electric motor Piston and cylinder with clevis arrangement Rack, gear and pinion Ball screws (C) 2001, Ernest L. Hall, University of Cincinnati

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Starting your application 

Size work piece

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Torque calculation 1 meter

W = mg

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Question 

An industrial robot must supply sufficient torque to rotate a 1 kg (2.2 lb) load held at the distal end of a 1 meter long gripper at an angular acceleration of 1 radian/second2 in the counter clockwise direction. Determine the total torque required of the gripper.

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Solution T T T T

 Ts  Td  F * d  I *  m * g * l  m * l ^ 2 *  (1kg) * (9.81m / s ^ 2) * (1m)  (1kg) * (1m*^2) * (1rad / s ^ 2)  9.81  1  10.81Nm

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Work cell layout    

Locate incoming parts Locate robot Locate outgoing parts Locate other machines

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Simple work cell layout 35"

35"

Input conveyor -1

Robot

3- Output conveyor

35"

2

Machine

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Cycle time analysis 

Assumptions   

  



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Cycle starts with arm located at position 1 Robot picks up part Then moves to position 2 Loads part into machine Returns to position 2 and waits Moves into machine and gets part Moves to output conveyor and releases part

Acc time = Dec time = 0.25 sec

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Acceleration time Velocity - ips

V

Time - sec 0.25

10/19/2015

T-0.25

(C) 2001, Ernest L. Hall, University of Cincinnati

T

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Distance calculation Velocity

V d2 d1

d3 Time - sec T-0.25

0.25

T

dT = d1+d2+d3 d1=.25*V/2 10/19/2015

d2=V(T-0.5)

d3=V(T-0.5)/2

(C) 2001, Ernest L. Hall, University of Cincinnati

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Try it 

How long does it take a robot to move 100 inches at 50 ips?

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Example         

dT = d1+d2+d3 d1=.25*V/2=.25*50/2 = 6.25 d2=V(T-0.5) d3=V(T-0.5)/2 = 6.25 dT = 12.5+50(T-.5) = 50T-12.5 100 =50T-12.5 87.5/50 = T T = 1.75 sec Total T = 1.75+.5=2.25 seconds

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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10/19/2015

Step

Action

Time (seconds)

1

Receive “Part 1.0 Ready Signal” from conveyor and move down 5”@10 ips

2

Grasp part

0.5

3

Lift part up 5”@10 ips

1.0

4

Move to location 2 @ 50 ips

1.5

5

Move 10” into machine @ 50ips

0.7

6

Lower part 5”@10 ips

1.0

7

Signal machine and 3.0 hold part while machine works on it (C) 2001, Ernest L. Hall, University of Cincinnati

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8

Raise part 5” @ 10 ips

1.0

9

Withdraw part 10” @ 50 ips

0.7

10

Move to location 3 @ 50 ips

1.5

11

Move down 5 “ @ 10 ips

1.0

12

Release part

0.5

13

Move up 5” @10 ips

1.0

14

Move to location 1 via location 2 @ 50 ips

2.5

Total time

16.9 sec

With 1.1 safety factor 18.6 sec 10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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14”

Output Welding Conveyor Station Welding Spots

08”

Base Plate Bracket

14”

Spot Welding Robot Radius of Robot Arm 20 in.

14”

Work Cell Layout

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Robot requirements that need to be determined for the application        

Payload and working range Arm and wrist configuration End-effector required Method of actuation Operation (servo or non-servo) Precision required Special features Commercial units available

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Configurations fit applications 

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Cartesian Application – assembly and machine loading Configuration – PPP Percentage – 18 Advantage – equal resolution, simple kinematics Disadvantage – Poor space utilization, slow speed

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Commercial robot selection worksheet Criteria

Requirement

Commercial Robot Candidate 1

Commercial Robot Candidate 2

Commercial Robot Candidate 3

Payload capacity Arm configuration Outer reach Inner reach Upper reach

Lower reach Horizontal reach or sweep Wrist configuration

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Keep benefits in mind 

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   

Five benefits that frequently are achieved through the application of industrial robots. Reduced costs Improved productivity Improved quality Elimination of hazards Greater flexibility

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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Any questions?

10/19/2015

(C) 2001, Ernest L. Hall, University of Cincinnati

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