HelloThursday, March 31, 2011
Measuring Unicycling                                EfficiencyThursday, March 31, 2011
Problem Definition                    • No method exists for quantitatively                           1) Monitoring trainin...
Unicycling Efficiency                                 LossesThursday, March 31, 2011
Efficiency Losses                    •      Acceleration and                           deceleration to maintain            ...
Efficiency: Reduce Drag                    •      Wear tight clothing                    •      Cover spokes of wheel      ...
Measuring Efficiency                    • Measure speed many times throughout                           individual wheel ro...
Data Collection                              Timing and TrackingThursday, March 31, 2011
Timing Option: Magnets                    •      “Hal Effect” sensor                           placed near spokes.        ...
Timing Option: Spokes                    •      Optical beam emitted                           through wheel to sensor.   ...
Timing: Rim Encoder                    •      Black tape placed at                           regular intervals on         ...
Rotation Tracking                    • Wide and narrow tape sections encode a                           specified pattern a...
Rotation TrackingThursday, March 31, 2011
Rotation TrackingThursday, March 31, 2011
Rotation Tracking                                   C D                           Data:Thursday, March 31, 2011
Rotation Tracking                                   C D                           Data:Thursday, March 31, 2011
Rotation Tracking                                     C D                           Data: 0Thursday, March 31, 2011
Rotation Tracking                                   C D                           Data: 0 1Thursday, March 31, 2011
Rotation Tracking                                   C D                           Data: 0 1 0Thursday, March 31, 2011
Rotation Tracking                                   C D                           Data: 0 1 0 0Thursday, March 31, 2011
Rotation Tracking                                   C D                           Data: 0 1 0 0 1Thursday, March 31, 2011
Rotation Tracking                                   C D                           Data: 0 1 0 0 1 1Thursday, March 31, 2011
Rotation Tracking                                   C D                           Data: 0 1 0 0 1 1 1Thursday, March 31, 2...
Rotation Tracking                                   C D                           Data: 0 1 0 0 1 1 1 0Thursday, March 31,...
Error & PrecisionThursday, March 31, 2011
Sources of Error                     Electronics            Timer/ Software            Tape Placement                     ...
Slew Rate                                         6                                         5                             ...
Slew Rate                                         6                                         5                             ...
Causes of Slew Rate                    • Tape edge transition is not instantaneous.                    • Transition time i...
Slew Rate                                         6                                         4                             ...
Error: Tape PlacementThursday, March 31, 2011
Tape InstallationThursday, March 31, 2011
Delay000000       R² = 0.918000000000000Untitled 1   Untitled 15 Untitled 29 Untitled 43 Untitled 57 Untitled 71 Untitled ...
Calibration                           Raw Velocity Data & Real OffsetThursday, March 31, 2011
Thursday, March 31, 2011
System OverviewThursday, March 31, 2011
Thursday, March 31, 2011
38640                                                    37880                                                    37848   ...
Raw DataThursday, March 31, 2011
Unicycling EfficiencyThursday, March 31, 2011
Thursday, March 31, 2011
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Unicycling Efficiency Measuring Device

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Short presentation about some key aspects of the function and design of the device I'm building to measure unicycling efficiency quantitatively.

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Unicycling Efficiency Measuring Device

  1. 1. HelloThursday, March 31, 2011
  2. 2. Measuring Unicycling EfficiencyThursday, March 31, 2011
  3. 3. Problem Definition • No method exists for quantitatively 1) Monitoring training, and 2) Comparing configurations for unicycles in terms of efficiency.Thursday, March 31, 2011
  4. 4. Unicycling Efficiency LossesThursday, March 31, 2011
  5. 5. Efficiency Losses • Acceleration and deceleration to maintain balance on unicycle. • Minimizing this leads to increased efficiency.Thursday, March 31, 2011
  6. 6. Efficiency: Reduce Drag • Wear tight clothing • Cover spokes of wheel with a disc or use bladed spokes • Adopt a more aerodynamic posture Source: Steed CyclesThursday, March 31, 2011
  7. 7. Measuring Efficiency • Measure speed many times throughout individual wheel rotations. • Use velocity profile to calculate efficiency.Thursday, March 31, 2011
  8. 8. Data Collection Timing and TrackingThursday, March 31, 2011
  9. 9. Timing Option: Magnets • “Hal Effect” sensor placed near spokes. • Spokes crossing sensor detected magnetically Source: SparkFun ElectronicsThursday, March 31, 2011
  10. 10. Timing Option: Spokes • Optical beam emitted through wheel to sensor. • Spokes break the beam, signal sent to processor. Source: todbot blogThursday, March 31, 2011
  11. 11. Timing: Rim Encoder • Black tape placed at regular intervals on reflective rim. • Leading tape edge triggers reflectance sensor.Thursday, March 31, 2011
  12. 12. Rotation Tracking • Wide and narrow tape sections encode a specified pattern around the wheel. • Second sensor detects HIGH on narrow sections, LOW on wide sections.Thursday, March 31, 2011
  13. 13. Rotation TrackingThursday, March 31, 2011
  14. 14. Rotation TrackingThursday, March 31, 2011
  15. 15. Rotation Tracking C D Data:Thursday, March 31, 2011
  16. 16. Rotation Tracking C D Data:Thursday, March 31, 2011
  17. 17. Rotation Tracking C D Data: 0Thursday, March 31, 2011
  18. 18. Rotation Tracking C D Data: 0 1Thursday, March 31, 2011
  19. 19. Rotation Tracking C D Data: 0 1 0Thursday, March 31, 2011
  20. 20. Rotation Tracking C D Data: 0 1 0 0Thursday, March 31, 2011
  21. 21. Rotation Tracking C D Data: 0 1 0 0 1Thursday, March 31, 2011
  22. 22. Rotation Tracking C D Data: 0 1 0 0 1 1Thursday, March 31, 2011
  23. 23. Rotation Tracking C D Data: 0 1 0 0 1 1 1Thursday, March 31, 2011
  24. 24. Rotation Tracking C D Data: 0 1 0 0 1 1 1 0Thursday, March 31, 2011
  25. 25. Error & PrecisionThursday, March 31, 2011
  26. 26. Sources of Error Electronics Timer/ Software Tape Placement Slew Rate 0 0.75 1.50 2.25 3.00Thursday, March 31, 2011
  27. 27. Slew Rate 6 5 4 Voltage (V) 3 2 1 0 0 5 10 15 20 25 30 35 40 45 Time (s) Square wave with no slew rate (ideal)Thursday, March 31, 2011
  28. 28. Slew Rate 6 5 4 Voltage (V) 3 2 1 0 0 5 10 15 20 25 30 35 40 45 Time (s) Square wave with visible slew rateThursday, March 31, 2011
  29. 29. Causes of Slew Rate • Tape edge transition is not instantaneous. • Transition time in signal causes slew rate. • Other causes of slew rate from electrical circuit elements are insignificant.Thursday, March 31, 2011
  30. 30. Slew Rate 6 4 2 Voltage (V) 0 0 200 400 600 800 1000 1200 1400 -2 -4 -6 250 μs Time (microseonds) Optical Sensor Response (simulated)Thursday, March 31, 2011
  31. 31. Error: Tape PlacementThursday, March 31, 2011
  32. 32. Tape InstallationThursday, March 31, 2011
  33. 33. Delay000000 R² = 0.918000000000000Untitled 1 Untitled 15 Untitled 29 Untitled 43 Untitled 57 Untitled 71 Untitled 85 Untitled 99 Untitled 113 Untitled 127 Untitled 141 Untitled 155 Untitled 169 Untitled 183 Untitled 197 Untitled 211 Delay over six revolutions with ideal time Thursday, March 31, 2011
  34. 34. Calibration Raw Velocity Data & Real OffsetThursday, March 31, 2011
  35. 35. Thursday, March 31, 2011
  36. 36. System OverviewThursday, March 31, 2011
  37. 37. Thursday, March 31, 2011
  38. 38. 38640 37880 37848 2 Error! 37564 Data 37704 37904 37640 37396 36844 38468 37940 38236 3 38032 • Stored in three-column 38788 38420 TSV text file 38020 38692 39004 • 82 KB / Km; 38472 38340 13,000 rows / Km 38988 39424 4 39148 • 39048 40 MB for 500 Km; 39468 40136 6.5M rows 39508 39404 39780 • 4GB capacity µSD card 40248 39760 1 39624 40352 40392 40288 40132 41016Thursday, March 31, 2011 40228
  39. 39. Raw DataThursday, March 31, 2011
  40. 40. Unicycling EfficiencyThursday, March 31, 2011
  41. 41. Thursday, March 31, 2011
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