1. FRC Pneumatics Nate Laverdure FRC Team 122

2. FRC Pneumatics, Nate Laverdure FRC Team 122 Everything I wanted to know aboutbut was afraid to ask Chief Delphi

3. What is this presentation? Goals: Teach you the words transducer, damper, and venturi

4. What is this presentation? Goals: Teach you the words transducer, damper, and venturi Attempt to: – Show that pneumatics have great advantages – if used correctly! – Provide a workable understanding of FRC pneumatics

5. What is this presentation? Goals: Teach you the words transducer, damper, and venturi Attempt to: – Show that pneumatics have great advantages – if used correctly! – Provide a workable understanding of FRC pneumatics My personal goal: inspire you to build your own pneumatic system!

6. What are pneumatics? Pneumatics use pressurized gas to effect a mechanical motion

7. What are pneumatics? Pneumatics use pressurized gas to effect a mechanical motion The working gas is typically air— 78%N 2 21%O 2 1%others

8. What are pneumatics? Other actuation systems: pneumaticpressurized gas hydraulicpressurized liquid electricelectrical energy

9. What aren’t pneumatics? Closed-loop systems: Pneumatic tires Inflatable game pieces

10. What aren’t pneumatics? Closed-loop systems: Pneumatic tires Inflatable game pieces Linear dampers (aka “gas shocks”)

11. Why should I use pneumatics? Strengths: Linear motion Adjustable force and speed Good stall behavior (Can maintain high force, even with no motion) Easy to configure Low marginal weight

12. What is marginal weight? 1 2 34 5 Actuators Weight Electric motors

13. What is marginal weight? 1 2 34 5 Actuators Weight Electric motors

14. What is marginal weight? 1 2 34 5 Actuators Weight Electric motors Marginal weight

15. What is marginal weight? 1 2 34 5 Actuators Weight Pneumatics Break-even point High initial weight Electric motors

16. Why should I not use pneumatics? Weaknesses: High initial weight Severely limited available positions Difficult to produce rotary motion Capacity limits Complex troubleshooting

17. Why should I not use pneumatics? Weaknesses: High initial weight Severely limited available positions Difficult to produce rotary motion Capacity limits Complex troubleshooting Mitigations: Add more actuators ‒Decreases average weight per actuator Use off-board compression ‒Caution: more severe capacity limits!

18. Why should I not use pneumatics? Weaknesses: High initial weight Severely limited available positions Difficult to produce rotary motion Capacity limits Complex troubleshooting Mitigations: Either open or closed No truly controllable multi-position actuators Various hacks have come close ‒Caution: may not be legal in FRC 2014!

19. Why should I not use pneumatics? Weaknesses: High initial weight Severely limited available positions Difficult to produce rotary motion Capacity limits Complex troubleshooting Mitigations: Bell crank or other linkage Rotary actuator (turbine) ‒Caution: severe capacity limits and extremely low torque!

20. Why should I not use pneumatics? Weaknesses: High initial weight Severely limited available positions Difficult to produce rotary motion Capacity limits Complex troubleshooting Mitigations: Use on-board compression ‒Caution: weight penalty! Use lower operating pressures Use spring-return cylinders

21. Why should I not use pneumatics? Weaknesses: High initial weight Severely limited available positions Difficult to produce rotary motion Capacity limits Complex troubleshooting Mitigations: Know your system! Create and maintain a flow diagram Practice responding to common problems

22. FRC pneumatics system HPMPLP

23. FRC pneumatics system HPMP … Vacuum LP 1 LP 2 LP 3 LP n

24. FRC pneumatics system HPMP Compression Accumulation Safety Control Actuation Control Actuation Vacuum … LP 1 LP 2 LP 3 LP n Subsystems:

25. Compression subsystem Components: Compressor CMP HP

26. Compression subsystem Components: Compressor Options: ViairThomasAlternatives 2011 - 20132003 - 2010??? - ??? CMP HP

27. Accumulation subsystem Components: Accumulator TANK HP

28. Accumulation subsystem Components: Accumulator Options: ClippardPneuaireAlternatives ? TANK HP

29. Safety subsystem Components: Pressure relief valve Manual vent valve HP

30. Safety subsystem Components: Pressure relief valve Manual vent valve Pressure relieving regulator – One on each leg Pressure gauge – One on each leg HPMP LP HP

31. Safety subsystem HPMP LP HP

32. Control subsystem Pneumatic components: Pressure switch Solenoid valve HP PS MP or LP cRIO

33. Control subsystem Pneumatic components: Pressure switch Solenoid valve Electrical components: Spike relay Digital sidecar Solenoid breakout module (cRIO) HP PS MP or LP cRIO

34. Control subsystem HP PS MP or LP cRIO

35. Diagramming the solenoid valve

36. Position & flow boxes Left actuatorRight actuator

37. Diagramming the solenoid valve External pilot Spring Lever Position & flow boxes Left actuatorRight actuator Piloted solenoid with manual override Solenoid Detent Push button

38. Diagramming the solenoid valve Position & flow boxes Left actuatorRight actuator 3-way 2-way 5-way 4-way

39. Example

40. “This is a single-acting 4-way, 2-position solenoid valve with lever override.”

41. Example

42. “This is a 4-way, 3-position, blocked center piloted solenoid valve with pushbutton overrides.”

43. Actuation subsystem Components: Cylinder – Double acting – Single acting (spring return) Rotary actuator (turbine)

44. Actuation subsystem Components: Cylinder – Double acting – Single acting (spring return) Rotary actuator (turbine) Vacuum actuator – Venturi – Suction cup

45. Actuation subsystem

46. Warning: Venturis require constant flow to maintain vacuum!

47. Bernoulli’s principle

48. Optional components Pressure transducer Flow control valve PT cRIO

49. Optional components PT cRIO

50. CMP PS HP MP LP TANK cRIO

51. FRC Pneumatics Nate Laverdure FRC Team 122