1. 2011 Indoor Aerial Robotics Competition Winston Moy Advised by: Dr. Jennifer Wang Emu (ēm(y)oō) : Flightless Australian bird resembling ostrich. Member of the family Dromaiidae.

2. Tasks Structure Design Construction Electronics Hardware Selection Implementation Control Software Research Coding

3. Objective Overview Unmanned/Micro Aerial Vehicle Urban Navigation Competition April 30, 2011

4. Scoring Size Multiplier (S) 1- ( VUAV / VMax ) Speed Points 40 * ( 120 / Trun ) Control Multiplier (C) Autonomous = 100%, RC = 10% Other (Misc) Took-off = 5 pts, Design, likability = 6 pts, etc. Score = S * C * ( Speed + Other )

5. Vehicle Constraints Size Contained within 5x5x5ft Safety Kill switch Control Autonomous or remote Design Custom or commercially available

6. Changes from Past Years Greater focus on, and heavily favors, rotorcraft Focus on vision and fight algorithms, not construction of the aircraft. Heavily favors fully autonomous systems

7. The Competition 5 Teams 4 Quadrotors At least 2 were bought online… or at Best Buy. Who knows. Parrot AR Drone

8. 2011 IARC Design Partially Buoyant Vehicle

9. 2011 IARC Design Modular Construction

10. 2011 IARC Design Three Degrees of Freedom

11. 2011 IARC Design Computations Done Remotely Laptop processes video Determines navigation Blimp executes decision Cam Feed Control Commands

12. Physical Realization Structure

13. Body Design - Original 7.4 V Battery Arduino 1.5” 6” 5” Top 3.7 V Battery Servo Side Front

14. Body Design - Final Interface Board 1.5” 7.4 V Battery 6” 5” Top Servos Side Front

15. Gondola Construction Materials

16. Gondola Construction Balsa: 1/4 and 1/8” square rods

17. Gondola Construction Carbon Fiber Tubes: 3/16 and 1/8” OD

18. Gondola Construction Frame Identical dorsal and ventral structure

19. Gondola Construction Frame Identical dorsal and ventral structure Glue cured while in compression

20. Gondola Construction Frame Identical dorsal and ventral structure Glue cured while in compression 2-D until last possible moment

21. Gondola Construction Carbon Fiber Simplified engine mounting

22. Gondola Construction Carbon Fiber Arduino tail boom

23. Gondola Construction Shaft Bearing Column

24. Gondola Design Elements Servo-Shaft Interface

25. An ME’s favorite part… Electronics

26. Microcontroller Requirements Digital Output PWM Analog Input Sensors Wireless Hardware Communication ?

27. Arduino Microcontroller Arduino FIO Built-in Xbee socket 6 P.W.M. channels 6 Analog I/O 3.3 Vout for sensors Battery or USB powered

28. Arduino Microcontroller Open Source IDE Free!!! Cross platform Win/OS X/Linux Easy serial comm. (USB, radio, etc) Many libraries, examples Codes like C++

29. Other Hardware Servos E-Sky EK2-0508 Motor Controller EZRun 18A-SL ESC Brushless DC Motors Sonar Range Finder LV-MaxSonar-EZ1 Camera Some unbranded, 2.4 GHz thing…

30. Circuit Board Goodness How to tie components together? Breadboard is too heavy, Arduino too far away.

31. Circuit Board Goodness How to tie components together? Back side of interface board.

32. Circuit Board Goodness How to tie components together? Consolidation will bring you victory!

33. Power Tested smallest battery in inventory 500 mAh 7.4V LiPo w/ a single motor 2 minutes at 100% & 4 minutes at 50% before noticeable drop in output.

34. Power ~500 mAh appeared to be sufficient Purchased a spare 450 mAh battery by Gens Ace based on discharge data

35. Software, Computer Vision, Flight Dynamics Control

36. Software Processing OpenCV library Arduino Firmata

37. Camera Dataflow Camera feed is composite (analog) Enters system via USB Stream passed through WinVDig Identified as video input device Filtered Passed into OpenCV library Blobs detected

38. Conceptualizing Emu How to control a 3-DOF platform. Hmm… Parameters Lift F-R Thrust L-R Turning Moment

39. Conceptualizing Emu How to control a 3-DOF platform. Parameters Lift F-R Thrust L-R Turning Moment Altitude Priority Control Software GUI/Dashboard Intuitive controls

40. Hardware and Software Interface Under Remote Control WASD/RF Direction & Rise/Fall Number keys Mode toggle In Autonomous Mode Cruise altitude pre-programmed Computer vision determines turning and moving forward

41. Flight Dynamics Two propellers can be rotated independently Thrusting Down = Lift Thrusting Same Direction = Forward/Reverse Opposing Thrust = Turning Combination of above = effective motion How do you mathematically define “turn right, while moving forward and going up”?

42. Flight Dynamics Lifting force is a function of servo angle. To compensate for loss of lift at non-zero angles, engine power should be multiplied by 1/cos() θ Lift = Thrust * cos(θ) ThrustAdjusted = LiftDesired / cos(θ) Note: Positive θ points the propellers forward, generates forward thrust.

43. Flight Dynamics LiftDesired is adjusted dynamically F-R thrust and turning moments are also functions of θ θ if (alt < desired) LiftDesired ++; else if (alt > desired) LiftDesired - - ; FF-R Thrust = ThrustAdj * sin(θ) MTurning = ± ThrustAdj * sin(θ) * L

44. Flight Dynamics Total F-R thrust: Total Turning Moment: F-R Thrust and Moments are known User Defined or Autonomously Set θ FF-R Total = ThrustAdj * sin(θL ) + ThrustAdj * sin(θR ) MTotal = - L*ThrustAdj * sin(θL ) + L*ThrustAdj * sin(θR )

45. 2 Equations with 2 Unknowns

46. Flight Dynamics Left Servo Angle: Right Servo Angle: Left Motor Power: Right Motor Power:

47. Computer Vision Processing + OpenCV 1.0 Library ‘blob()’ function applied to images, returns: Area Centroid Inside another blob? Perimeter Pixels Defining points Bounding rectangle

48. OpenCV in Action Raw Image Filtered Image Filtered Image Blob Tracked

49. Images with Wireless Camera Practice competition Sampled colors to calibrate tracking & blob-detection programs

50. Navigation Algorithm Mode 0 – Off Mode 1 – Take-Off Mode 2 – Cruise Mode 3 – Approach Mode 4 – Landing Mode 5 – Controlled Abort Mode 6 – Emergency Stop Mode 7 – Remote Operation

51. Navigation Algorithm

52. Progress Report, Brain Fluff, & The Future Conclusion

53. State of the Emu

54. State of the Emu Frame is complete. Servos and motors function properly Last minute weight/balance shifting T.B.D. Electronics All systems fully functional. R/F interference not catastrophic… ideally. R/C code done. Autonomous is 70% done* Control requires fine-tuning.

55. Budgetary Concerns Parrot AR Drone is $300 Reused as many items as possible from last year’s failed vehicle (the Eagle) Primary Costs (2011):

56. Future Directions Structure Camber angle with motors Minimize balsa structure more Feedback Accelerometer & Gyroscope More sensors w/ serial comm. Re-spec. Propellers, ESC’s, and Servos Digital communication Wi-fi or a non 2.4 GHz protocol If I had more time, money, & people…

57. Special thanks to… For contributions large and small… Dr. Wang – Support as advisor. Dr. Grega – Letting me steal Aero Design supplies. TCNJ Chemistry – Helium. Brian Geuther – Tools, help, brain-storming. Brian Carrigan – Circuit board prototyping supplies. Steve Turner – Windows XP Pro.

58. Questions?