1 / 36

Control Team

S P A C E Structures, Propulsion, And Control Engineering C e n t e r. Control Team. Faculty Advisors Dr. Helen Boussalis Dr. Khosrow Rad Dr. Charles Liu. Student Assistants Jessica Alvarenga Alok Desai Harshit Tarsaria Kimberly Castro Heather Rudow Eric Diaz.

lou
Download Presentation

Control Team

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. S P A C E Structures, Propulsion, And Control Engineering C e n t e r Control Team Faculty Advisors Dr. Helen Boussalis Dr. KhosrowRad Dr. Charles Liu Student Assistants Jessica Alvarenga Alok Desai Harshit Tarsaria Kimberly Castro Heather Rudow Eric Diaz NASA Grant URC NCC NNX08BA44A

  2. Outline • Background • Current Work • Integration of PPA to DSP • Multiple Sensor Calibration • Modeling of PPA to State-Space • Future Work • Timeline NASA Grant URC NCC NNX08BA44A

  3. Background NASA Grant URC NCC NNX08BA44A

  4. James Webb Space Telescope • Bigger Viewing Dish • 6.5m Mirror Panel • Gold-plated Beryllium Mirrors • Six times the collecting area • Deep Space • No atmospheric interference • Lag time due to distance • Segmented System • Control Algorithm • Decentralized System • Reconfigurable • Fault Detection and Isolation • Maintain Shape Control under Disturbance • IR Detection • Studies of Big Bang NASA/JPL-Caltech/R. Hurt (SSC) NASA Grant URC NCC NNX08BA44A

  5. SPACE Telescope Testbed 5 NASA Grant URC NCC NNX08BA44A

  6. Control Requirements • Shape Control Hold nominal paraboloid shape • Pointing Control Accuracy of 2 arc second • Vibration Suppression 100:1 • Control Bandwidth 30HZ NASA Grant URC NCC NNX08BA44A

  7. Current Work NASA Grant URC NCC NNX08BA44A

  8. Ongoing Work NASA Grant URC NCC NNX08BA44A

  9. Integration of Pointing Control into Shaping Control NASA Grant URC NCC NNX08BA44A

  10. Objective • H-infinity controller to handle both Shaping and Pointing (Currently just demonstrates shaping) • Integrate the Peripheral Pointing Architecture (PPA) Control with the Digital Signal Processor (DSP) • Some hardware/software changes will need to be made NASA Grant URC NCC NNX08BA44A

  11. Current Configuration DSP Shape Control Shaping and pointing control are separate Testbed PPA Motion Controller Pointing Control Pointing Architecture NASA Grant URC NCC NNX08BA44A

  12. Desired Configuration Shape and Pointing Control Shaping and pointing control are integrated Testbed DSP PPA Motion Controller Pointing Architecture NASA Grant URC NCC NNX08BA44A

  13. Functional Block Diagram NASA Grant URC NCC NNX08BA44A

  14. Communication from DSP to DAQ • Generate a sine wave digital test signal from DSP to free D/A channels • From D/A channels, test signal will be converted to analog • Converted analog signals will be input to USB-6251 DAQ • The acquired data will be acquired by LabVIEW NASA Grant URC NCC NNX08BA44A

  15. DSP Board(Pentek 4285) • MIX-VME baseboard it has: • 40 MHz 68030 processor • 4 processors used on the SPACE test-bed (numbered 0,1,4,5 or A,B,E,F) • Offers communication ports to the host computer and other modules such as the A/D & D/A NASA Grant URC NCC NNX08BA44A

  16. Digital to Analog Converter (DAC) • Purpose: • Converts digital to analog voltage • High performance 8-channel, 16-bit converter • 18 channels are currently used on the test-bed • 16-bit resolution, sampling frequency up to 250 kHz NASA Grant URC NCC NNX08BA44A

  17. Communication from LabVIEW to PPA • Voltage signals from DAQ must be converted into linear displacements for the two PPA actuators • Displacement must then be converted to ASCII commands for the ESP • Position of both PPA actuators may be queried and returned to LabVIEW for position verification and/or for feedback to the DSP NASA Grant URC NCC NNX08BA44A

  18. DSP-to-PPA GUI • Must first establish a “home” position (a spatial origin of reference) • Convert sampled voltage signal into a two-dimensional displacement • i.e. – • G1 and G2 are gains to be experimentally determined • Convert displacement into ASCII command and send to ESP to send to PPA • i.e. – 01MA0.03 -> tells ESP to move actuator 1 to an “absolute” position of 0.03mm • Retrieve actuator positions of PPA from ESP NASA Grant URC NCC NNX08BA44A

  19. Sensor Network Calibration NASA Grant URC NCC NNX08BA44A

  20. Calibration • Sensor linearity 8 volts/ 2 mm • Operate between +/- 10 Volt • Sensor Testing Module NASA Grant URC NCC NNX08BA44A

  21. Sensors • 18 collocated sensor • 24 edge sensor NASA Grant URC NCC NNX08BA44A

  22. Single Sensor Calibration • LabVIEW GUI has been developed to aid with sensor calibration checks • Requires removal of sensor from holder • Prone to human errors when replacing • Maintain offset through entire procedure • Original offset • During calibration check • Placing back onto the structure • Tedious and time consuming NASA Grant URC NCC NNX08BA44A

  23. Sensor Network Calibration Check • Eliminate the need for removal of the sensors from holders • Eliminate as much human error as possible • Being able to check multiple sensors at once NASA Grant URC NCC NNX08BA44A

  24. Block Diagram LabView DAQ(Ao) Testbed Actuators DAQ(AI) Panel Sensors NASA Grant URC NCC NNX08BA44A

  25. PPA Structure Modeling NASA Grant URC NCC NNX08BA44A

  26. Background • We know the dynamics of all the components of a segmented telescope testbed • Now, we will focus on model identification, implementation, and control design for the PPA NASA Grant URC NCC NNX08BA44A

  27. Model Identification of A Segmented Telescope Testbed NASA Grant URC NCC NNX08BA44A

  28. Laser Platform NASA Grant URC NCC NNX08BA44A

  29. FEMAP Platform Design NASA Grant URC NCC NNX08BA44A

  30. Platform Design NASA Grant URC NCC NNX08BA44A

  31. Hexagonal Part Design NASA Grant URC NCC NNX08BA44A

  32. Platform with Base Design NASA Grant URC NCC NNX08BA44A

  33. Future Work NASA Grant URC NCC NNX08BA44A

  34. Timeline NASA Grant URC NCC NNX08BA44A

  35. Timeline NASA Grant URC NCC NNX08BA44A

  36. Questions? Thank You NASA Grant URC NCC NNX08BA44A

More Related