Autonomous Rendezvous System Capstone Design Proposal

# Autonomous Rendezvous System Capstone Design Proposal

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## Autonomous Rendezvous System Capstone Design Proposal

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1. Autonomous Rendezvous SystemCapstone Design Proposal Chase Davis Daniel Phifer Nimesh Patel ReNina Fields Larry Lybrook Rachael Green Matthew Wright Eric Kneynsberg Jimmy Simmons University of Alabama Department of Electrical and Computer Engineering

2. Presentation Agenda • Documentation • Validation plan • General schedule and budget • Safety and environmental impact • Problem statement • Background information • Possible overall solutions • Plan of action • Detailed specifications • Platform • Wireless communication • Image processing • Navigation • Control console

3. Problem Statement • Rendezvous is considered successful when: • ∆X = 2 inches • ∆Y = ± 2.00 inches • ∆Yaw = ± 8.00 degrees • Chase vehicle is to rendezvous with target given starting requirements: • The x and y position for the chase vehicle is x = sqrt(9-y^2) • The angle of incidence, Ɵ, is such that -tol < Ɵ < tol • The tolerance will be determined once the infrared sensors have been tested • The yaw is equal to Ɵ (front of vehicle pointing at target)

4. Background • Three space stations • Skylab • Mir • International Space Station • Mir collision • Automated Transfer Vehicle (ATV) • May 8th , 2007 Autonomous Space Transport Robotic Operations (ASTRO)

5. Background • 3-Dimensional problem • Orbital rendezvous and docking • 6 degrees of freedom • 2-Dimensional problem • Capstone Fall 2007 • 3 degrees of freedom

6. Possible Overall Solutions • Triangulation▣ • Received/transmit signal strength of wireless modules • Very high precision and accuracy • Camera only • Enables a high degree of precision • Computationally expensive • IR sensors and compass only • Cheap • Easy to configure • Not accurate enough for the precise mechanics involved in docking

7. Overall System • IR sensors, compass and a camera • Phase 1▣ • IR sensors and compass provide a coarse but fast way of zeroing Y and Yaw • Move chase vehicle 2 feet out from stationary target (2,0,0) • Phase 2 • Camera provides the needed precision to approach the target carefully, slowly, and with enough accuracy to rendezvous/zero X • Chase vehicle slowly approaches stationary target from its position 2 feet away

8. System Overview

9. Plan of Action • Three modules: Chase Vehicle Computer Target • Five sub-systems • Platform • Wireless communication • Image processing • Navigation • Control console

10. Plan of Action • Develop each sub-system completely independent of other sub-systems • Integrate each sub-system into the overall system • Modify the sub-system to ensure proper interaction with the other sub-systems and module • Test, validate, and refine the system • Validate the performance of each sub-system • Validate the proper interaction between sub-systems • Validate the overall system performance

11. Sub-system Communication

12. Platform Possibilities • Chase • TK1 Basic Kit • Palm Pilot Robot Kit (PPRK) • Octabot • Wheel position • Scooterbot II • Wheeled • Servo driven • Two 7” diameter decks • Cost \$59.95 • Target • Façade • Possibility of docking X-axis view Y-axis view

13. Platform Testing Plan • Chase • Testing done using microcontroller pulse width modulation (PWM) • Movement • Clockwise • Counter clockwise • Forward • Reverse • Speed • Five different speeds • Effects of overall equipment weight • Target • Contingent on docking Group Members: Eric Kneynsberg, Larry Lybrook, Nimesh Patel, Daniel Phifer

14. Power Budget • Chase • Target * Measured in Lab

15. Wireless Kit Possibilities Since 3 modules and development boards are needed, and the XBee Starter Kit only provided 2 of each, 1 more module and board will be purchased • XBee-PRO Starter Kit • 60 mW output power • 1-mile range • RS-232 & USB development boards • 2 OEM RF modules • Cost \$179.00 • XBee Starter Kit • 1 mW output power • 100 ft. indoor range • RS-232 & USB development boards • 2 OEM RF modules • Cost \$129.00

16. XBee Starter KitDetailed Specifications • Performance • Power output: 1mW • Indoor range: Up to 100 ft • Baudrate • Interface baudrate: 115,200 • Operating frequency: 2.4 GHz • Networking • Networking topology: peer-to-peer, point-to-point & point-to-multipoint • Error handling • Retries and acknowledgements

17. Wireless Testing Plan • Simultaneously send data from control console and target to chase vehicle • Send data from chase vehicle to target and control console • Look for a proper transition on chase vehicle between control console channel and target channel Group Members: Rachael Green, Daniel Phifer, ReNina Fields

18. Image Processing Possibilities • Terasic TRDB_DC2 • Not useable with microcontroller • CMUCam1 - \$109 • Low resolution • CMUCam3 - \$239 • High price, unneeded functionality • CMUCam2 - \$179 • Compromise in price and image resolution • Available for immediate testing

19. Image Processing Testing Plan • Test for most effective beacon • Contrasting printed image • LEDs • Test color tracking function • Distance from beacons • Angle of incidence • Camera/beacons in motion • Test distance measurement • Assume 90° incident angle • Resolution • Repeatability Group Members: Matt Wright, Jimmy Simmons, Rachael Green, Nimesh Patel

20. Navigation • Camera – CMU Cam 2 • IR sensors • Infrared “ranger” sensors will help find the target • Operating supply voltage of 4.5 to 5.5 Volts • Long range IR - Sharp GP2Y0A02YK \$12.50 • 8” to 60” range • Short range IR – Sharp GP2D120 \$12.50 • 1.5” to 12” range • Compass • Devantech R117 \$52.00 • Dinsmore compass \$14.00 • Optical sensors • Still researching ~\$1.08

21. Navigation Possibilities • Altera Cyclone II FPGA Starter Development Kit • Computation power • Learning curve • Price \$150.00 • Adapt9S12E128 Basic Module with 112-pin MCU • Equipment and language familiarity • Size • Price \$83.00 • Limited memory

22. Navigation Testing Plan • IR sensors • Test and validate ranges and detection surfaces • Compass • Compare readings from compass against an analog compass to test accuracy and precision Group Members: Eric Kneynsberg, Matt Wright, Jimmy Simmons, ReNina Fields, Chase Davis

23. Control Console Possibilities • MatLab • Excellent math and graphing capabilities • Image processing toolboxes • Slower processing • Not stand-alone • C# • Better visuals • More elegant and efficient design • Stand-alone program • Need .NET Framework • LabView • Very fast data acquisition (DAQ) • Numerous powerful functions • Learning curve • Expensive DAQ modules • Not stand-alone

24. Control Console Solution • Matlab • Powerful math and graphical functions which allows for future upgrades • Slower processing is not detrimental • Reduced learning curve

25. Control Console Testing Plan • MatLab simulation program • Mimic movement of vehicle • Include code to manipulate vehicle Group Members: Chase Davis, Jimmy Simmons, Eric Kneynsberg, Larry Lybrook

26. Documentation • The group will provide the user with: • User Manual • System Specification Document updated weekly • Each sub-system will be independently documented • Documentation responsibilities will be shared by all team members The group guarantees to deliver a prototype rendezvous system suitable for use as a demonstration during departmental recruiting activities by December 2007

27. Validation Plan • Validate each sub-system before integration • Check for desired behavior, performance, stability • Validate each sub-system after integration • Check for proper interactions with other sub-systems, stability, performance • Validate the system • Check for completion of objective

28. Validation Plan • Ad-hoc method of validation • Small scale • No plans for mass production • Limited access to specialized testing equipment • Limited time to implement and refine a systematic validation procedure • Acceptance will be defined by client’s acceptance standards and the equipment’s rated tolerances

29. Estimated Budget

30. Current Budget

31. Schedule

32. Safety Problems • Control system failure • Collision with people or other objects • Possible hazardous materials in system components • Possible hazardous payloads

33. Collision Avoidance • Long range operation uses long range IR sensors • Line up yaw and Y axis from long range • Short range operation uses short range IR sensors and color camera • Stop movement if IR sensor and camera data don’t match or are out of expected ranges • Variable speed based upon distance from target

34. Conclusion • Simulation of 3D rendezvous problem through 2D problem solving • Breakdown problem into sub-systems • Platform • Wireless communication • Image processing • Navigation • Control console • Safety concerns • Collision avoidance • Overall deliverable • Working prototype that can rendezvous autonomously with a target within system specifications

35. Questions?