Introduction to Robotics

1. Introduction to Robotics Gulf Coast Community College (Computer Automation & Robotics Technology)

2. Applications of Robots

3. Welding Applications Arc Welding Electron Beam Flux Cored Welding Mig Welding Plasma Cutting Resistance Welding Robot Laser Welding Spot Welding Tig Welding Welding Automation Double click on each link to see video clip applications

4. Material Handling Applications Dispensing Injection Molding Machine Loading Machine Tending Material Handling Order Picking Packaging Palletizing Part Transfer Pick and Place Press Tending Double click on each link to see video clip applications

5. Many other Applications of Robots Bonding / Sealing Cleanroom Deburring Drilling Flame Spray Foundry Grinding Material Removal Milling Painting Automation Polishing Robotic Assembly Robotic Coating Thermal Spray Waterjet Double click on each link to see video clip applications

6. Robotics Lab at GCCC Robotics Lab at Vincennes University

7. RoboticsLab 4 Adept Robots 3 Cobra Robots with Vision Systems

8. Parts of a Robot System

9. Parts of a Robot Controller

11. 5 types of Robot Coordinates Cylindrical Coordinate Cartesian Coordinate SCARA Cartesian or Cylindrical Coordinate Spherical Coordinate Revolute Coordinate

16. Programming Types • 1. Non-Servo Point-to-Point • 2. Servo Point-to-Point • 3. Continuous Path

17. Non-Servo Point-to-Point Points limited to “Stops” or end of extension and retraction

18. Can be either Hydraulics and Pneumatics

19. Servo Point-to-Point Has the ability to stop at any x-y-z-r coordinate in the work envelope

20. Continuous Path “Lead through Teach” move and play back

21. SCARA Robot “Selected Compliance Assembly Robot Arm”

22. SCARA Robot Typically 4 Axis but a few have a 5th axis: (Pitch)

23. Robots can be mounted up side down and travel as in this GANTRY robot.

24. Degrees of Freedom Cartesian: X, Y, and Z

25. Add Pitch, Roll, and Yaw to X,Y, and Z gives 6 degrees of Freedom

26. Pitch, Roll, and Yaw typically at the Robot Wrist

28. More degrees of freedom

29. Types or Grippers

30. Parallel Grippers

31. Manually Adjustable Parallel Gripper

32. Force Sensor

33. Vacuum Grippers

34. Servo Systems Introduction Servomotors are available as AC or DC motors. Early servomotors were generally DC motors because the only type of control for large currents was through SCRs for many years. As transistors became capable of controlling larger currents and switching the large currents at higher frequencies, the AC servomotor became used more often. Early servomotors were specifically designed for servo amplifiers. Today a class of motors is designed for applications that may use a servo amplifier or a variable-frequency controller, which means that a motor may be used in a servo system in one application, and used in a variable-frequency drive in another application. Some companies also call any closed-loop system that does not use a stepper motor a servo system, so it is possible for a simple AC induction motor that is connected to a velocity controller to be called a servomotor. http://zone.ni.com/devzone/cda/ph/p/id/233

35. Servo Systems Introduction (Continued) Some changes that must be made to any motor that is designed as a servomotor includes the ability to operate at a range of speeds without overheating, the ability to operate at zero speed and retain sufficient torque to hold a load in position, and the ability to operate at very low speeds for long periods of time without overheating. Older-type motors have cooling fans that are connected directly to the motor shaft. When the motor runs at slow speed, the fan does not move enough air to cool the motor. Newer motors have a separate fan mounted so it will provide optimum cooling air. This fan is powered by a constant voltage source so that it will turn at maximum RPM at all times regardless of the speed of the servomotor. http://zone.ni.com/devzone/cda/ph/p/id/233

36. Servo Systems Introduction (Continued) One of the most usable types of motors in servo systems is the permanent magnet (PM) type motor. The voltage for the field winding of the permanent magnet type motor can be AC voltage or DC voltage. The permanent magnet-type motor is similar to other PM type motors presented previously. Figure 11-83 shows a cutaway picture of a PM motor and Fig. 11-84 shows a cutaway diagram of a PM motor. From the picture and diagram you can see the housing, rotor and stator all look very similar to the previous type PM motors. The major difference with this type of motor is that it may have gear reduction to be able to move larger loads quickly from a stand still position. This type of PM motor also has an encoder or resolver built into the motor housing. This ensures that the device will accurately indicate the position or velocity of the motor shaft. http://zone.ni.com/devzone/cda/ph/p/id/233

37. Servo Systems • Advantages of Servo Motors • Some of the advantages of servo motors over stepper motors are as • follows: • High intermittent torque • High torque to inertia ratio • High speeds • Work well for velocity control • Available in all sizes • Quiet • Disadvantages of Servo Motors • Some of the disadvantages of servo motors compared with stepper • motors are as follows: • More expensive than stepper motors • Cannot work open loop - feedback is required • Require tuning of control loop parameters • More maintenance due to brushes on brushed DC motors http://zone.ni.com/devzone/cda/ph/p/id/233

38. Servo Systems Introduction (Continued) http://zone.ni.com/devzone/cda/ph/p/id/233

39. Servo System: Servo Motor

40. Servo System: Servo Drive & Servo Motors

41. Analog Servo System Computer D/A Comparator Controller Amplifier Actuator Tack Encoder, Resolver, LVDT, or Pot

42. Computer D / A Converter Amplifier/Drive Actuator Tack Encoder, Resolver, LVDT, Or Pot A / D Converter ADC not needed with digital encoder Digital Servo System

43. Optical Encoders VDC VDC One Track Incremental Encoder Two Track Incremental Encoder

44. Optical Encoders (Absolute Encoders) VDC 0 1 2 3 4 5 6 7 8 9 10 Course = 6 Fine = 530

45. Resolver Armature Field 1 Sine Wave Field 2 Cosine Wave 90 degrees out of phase

46. Links to Servo Systems What’s a Servo? http://www.seattlerobotics.org/guide/servos.html Your Basic Servo Tutorial http://www.hooked-on-rc-airplanes.com/servo-tutorial.html How do servos work (small servos for RC etc.) http://www.youtube.com/watch?v=-XSXfqd1N58 DC servo driver DCS-140 with Siemens DC servo motor work on 200VDC http://www.youtube.com/watch?v=m5Uxb1gTsZU

47. The End