The document discusses programmable logic controllers (PLCs) and industrial robots. It defines PLCs as digitally operating electronic devices that use programmable memory to implement logic functions to control machines and processes. PLCs have input/output modules, memory, and peripherals. The document also discusses ladder logic diagrams used to program PLCs to control sequences like having a robot unload parts from one machine and load parts into another machine.

1. Programmable Logic Controller and Robotics

2. An Industrial Automation System PLC coordinates all the motion Robot is a key component

3. A small PLC (Allen Bradley MicroLogix 1000) (Courtesy of Allen-Bradley).

4. Definition of PLC PLC is a digitally operating electronic apparatus which uses a programmable memory for the internal storage of instructions by implementing specific functions such as logic sequencing, timing, counting, and arithmetic to control, through digital or analog input/output modules, various types of machines or processes. Modern PLC can be viewed as specialized computer Specialized in logic control Handle harsh and noisy environment

5. Structures

6. Input/output module Analog inputs Flow sensors Humidity sensors Potentiometers Pressure sensors Temperature sensors Analog outputs Analog meters Analog valves and actuators DC and AC motor drives Digital input/output Bar code, encoder Display Special purpose I/O PID controller Fast input Network module

7. Memory ROM RAM PROM EPROM etc

8. Peripherals Operator console Printer Simulator EPROM loader Network communication PC based programming software

9. Functions of PLC Relay Timer and counter Program control Arithmetic Data manipulation Data transfer Others, such as sequencers

10. A Relay

11. A counter

12. Counter timing diagram (the count value is 5)

13. A timer

14. Timer timing diagram (the timing value is 5)

15. Logic control Control actions are taken by making decisions depending on the values associated with various inputs or variables and the control logic in the program. Decisions by attributes (go-nogo decision) Is the machine turned on? Is the gate to the work cell open? Has the AGV arrived at the docking station? Decision by variables How deep is the hole? What is the cutting speed? What is the required surface finish? How many parts are to be made?

16. Logic control Attribute decision can be represented by a logic variable (true or false) and its value can be determined by a logic expression Boolean algebra is used for logic expression

17. Logic network diagram and ladder diagram

18. Example 1 A robot is to be used to unload finished parts from a machine onto an AGV and to load raw parts from the AGV to the machine. Assume that there are sensors at the AGV's docking station to indicate the arrival of a vehicle and onboard sensors indicating whether the vehicle has brought a raw part to be processed as well as whether the AGV has space to carry away a finished part. Also assume there are sensors on the machine to indicate whether the machine is loaded with a part and also to signal completion of part processing. The robot is required to unload a processed part from the machine onto the AGV, pick up a new part for processing from the AGV, and load it onto the machine. The AGV is to be dispatched after completion of the cycle. Construct a ladder logic diagram for this task.

19. Identify I/Os 01 AGV has arrived 02 AGV is carrying a new part to be processed 03 AGV has space to store a processed part 04 Machine has a finished part to be unloaded 20 Unload old part from machine onto the AGV 21 Pick new part from the AGV and load onto the machine 22 Dispatch the AGV

20. The Ladder Diagram

21. Features of Ladder Diagram A ladder logic diagram is made up of inputs and outputs connected according to the appropriate logic. Each rung in the ladder represents a set of logical relationships between the inputs that leads to a particular output. The output from one rung of the ladder could be used as an input in another rung of the same ladder. Except when special provisions are made, it is considered that all rungs in a given ladder logic diagram are executed simultaneously, so the order of the rungs on the ladder in general does not matter.

22. PLC scan

23. Example 2

24. Identified I/Os

25. Program

26. Wiring diagram

27. Example 3 During the powder metallurgy process, a punch is used to press blended metal powder into a compact inside a die. A pushbutton is used to start the process. When the start button is pressed, the die is filled with powder. The punch is then advanced and it applies pressure to the powder for a duration of 10 s, after which it is retracted. The pressed compact is then ejected from the die and the cycle repeats. The cycle can be interrupted by pressing a stop button. If the stop button is pressed, the punch is required to retract (if it had been advanced) before the process is stopped. We are required to construct a ladder logic diagram for this task.

28. Identify I/Os

29. Ladder Diagram

30. Example 4 This example illustrates the use of both the timing and counting functions. Consider a production line in which parts requiring processing are brought to a machine by a conveyor. A robot is used to load parts from the conveyor onto the machine and, after the part has been processed, unload the part from the machine and place it on a pallet. The cycle time for processing each part is 10 min. The robot is to palletize the parts by placing 125 parts on each pallet. The parts are to be arranged on the pallet in five layers of 25 parts each. Once a pallet is complete, it is dispatched and a new pallet is started. An allowance of 30 s is to be made for pallet dispatching and presentation of a new pallet. Construct a ladder logic diagram to effect the required control.

31. Identified I/Os 10 Machine has a part to be unloaded 30 Load machine with a new part 40 Unload a process part from the machine 45 The current pallet layer is full 48 Increment layer being palletized by 1 50 The pallet is full-dispatch 60 Present a new pallet C100 Up counter with limit set to 25 C200 Up counter with limit set to 5 T250 Timer with limit set to 600 s T300 Timer with limit set to 30 s

32. Ladder Diagram

33. Design methods for ladder diagram

34. Truth table

35. Ladder diagram for Example 10.2

36. State diagram

37. Rules of State Diagram

38. State diagram for Example 10.4

39. Outline What is industrial robot? Classification of robot Basic components in a robot Robot in Manufacturing Typical applications Selection of Robot Brief introduction to robot kinematics Basics of robot kinematics Economy justification of robot

40. 1. What is robot? In a broad sense, any autonomous machine can be called a robot. Industrial robot is a general-purpose computer-controlled manipulator consisting of several rigid links.

41. Why do we use robot? Flexible Disadvantage Slow Accuracy problem

42. Types of industrial robots Serial manipulator Parallel configuration

43. Further Classification of Serial Manipulator Cartesian Robot Gantry Robot

44. Further Classification of Serial Manipulator Cylindrical Robot

45. Further Classification of Serial Manipulator Spherical Robots Articulated Robots

46. Further Classification of Serial Manipulator SCARA

47. Robot Joints Prismatic joint Revolving joint

49. Robot Working Envelope

50. Robot classification using control methods Point-to-Point control Continuous path control Controlled path robot

51. Forward and backward kinematics analysis

52. Forward and backward kinematics analysis

53. Forward and backward kinematics analysis

54. 2.1 Typical Applications Welding

55. Typical Applications Assembly

56. Typical applications Deburs

57. Assembly headlamp

58. Robot Selection Size Degree of freedom Velocity Actuator type Control mode Repeatability Lift capacity …

59. Example

60. A single machine robotic cell application

61. Cycle time calculation example

62. Another example: double grip robot

63. Example