This presentation is based on the case of development of Instabeat, an innovative swimming tracker. The slides contain hints on how to organize development process, which sensors to use, how to analyze raw data and alternatively use tracking systems. This presentation by Mykola Shatokhin, GlobalLogic expert, was delivered at GlobalLogic Lviv C++ TechTalk on September 15, 2016. Learn more here: https://www.globallogic.com/ua/gl_news/globallogic-lviv-c-techtalk-summary/

1. 1
Confidential

2. 2
How to make a motion tracking
device
Mykola Shatokhin
Software Engineer
15.09.2016

3. 3
Instabeat

4. 4
1. Wearable devices
2. Device designing
3. Data analyzing
4. Gotchas
5. Summary
Agenda

5. 5
Wearable devices

6. 6
Device designing

7. 7
• Idea
• Sensors and mount place
• Collecting data
• Analyzing algorithm
• Related software
Device designing

8. 8
Mount position

9. 9
• Prepare protocol
• Ask athletes to help
• Make video
Collecting data

10. 10
Don’t be a racist

11. 11
Annotating

12. 12
Data analyzing

13. 13
Accelerometer
Gyroscope
Raw data

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Sliding window

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Where:
n – window size,
x – signal values in current window,
μ – window mean value.
Energy

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Accelerometer
Gyroscope
Energy

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Where:
n – axis count,
w – weight coefficient,
e – energy value.
Weighted energy

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Weighted energy

19. 19
Accelerometer axises

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Energy + acceleration mean (scaled amplitude)

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Signal smoothing

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Where,
n – filtering window size,
m – filtered value index,
x – signal value.
Simple Moving Average filter

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Signal smoothing

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Smoothed energy and acceleration

25. 25
Decision boundary

26. 26
Styles

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• Simplicity
• Speed
• Real time processing
Advantages

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• Low accuracy
Disadvantages

29. 29
• Sleep tracking
• Brain-Computer interface
• Games
Alternative usage

30. 30
Sleep tracking

31. 31
Brain-Computer interface

32. 32
Games

33. 33
Gotchas

34. 34
• Calibration
• Data transmission
• Stability
Gotchas

35. 35
Why C++?

36. 36
Summary

37. 37
Thank you
Q/A?
Mykola Shatokhin
Software Engineer
mykola.shatokhin@globallogic.com