1. Intro to Inertial Elecia White Logical Elegance, Inc. Embedded.fm @logicalelegance

2. Plans  60%: Accelerometer, gyro, magnetometer  30% Navigation is hard  15% Kalman filters, quaternions are awesome  10% Calibration is expensive  8% Summary of sensors, applications, costs

3. You are here. Intro to Inertial Sensors

4. Sensors  Accelerometers  Gyros  Magnetometers

5. Accelerometer

7. Sensors  Accelerometers  measure gravity  Gyros  Magnetometers

8. Gyros

9. Gyros Angular Rate Sensors

10. Sensors  Accelerometers  measure gravity  Gyros Angular rate sensors  measure spinniness  Magnetometers

11. Magnetometer

12. Sensors  Accelerometers  measure gravity  Gyros Angular rate sensors  measure spinniness  Magnetometers  measure north and magnets

13. Midpoint Quiz!  Stickers!  Books!  Win now!  Exclamation points are free!!

14. Axis

16. Look! Pretty lights!  Accelerometers  measure gravity (apples)  Gyros Angular rate sensors  measure spinniness (gestures)  Magnetometers  measure north and magnets (compass)

17. Where am I? Navigation is hard

18. Accelerometer

20. Kidnapped and Blindfolded

21. Position Calculation

22. Kalman Filter "Basic concept of Kalman filtering" by Petteri Aimonen

23. Kalman Filter

24. I Quaternions

25. http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles

26. Calculate heading https://github.com/adafruit/Adafruit_9DOF/blob/master/Adafruit_9DOF.cpp

27. Calculate heading: A+M https://github.com/adafruit/Adafruit_9DOF/blob/master/Adafruit_9DOF.cpp

28. Navigation remains difficult. Tactical Considerations

29. All sensors are temperature sensors, some measure other things as well.

30. Things to ask sensor vendors

31. Acronymic Combinations  A+G = Vertical gyro,  A+M = Tilt compensated compass  A+G+M = Attitude heading reference (AHRS)  A+G+M+GPS = Fusion navigation solution  IMU, IMU with nav library  9DOF – accel + gyro + mag  10DOF – barometric and/or temperature  Barometric is for altitude but only good for relative measurements

32. Cost comparison  Prices change pretty rapidly  Not recommendations, not exact SensorSpecificPrice BoardPrice (1kq) AccelMMA8451 ADXL345 $8 (Adafruit) $18 $1.20 $4.70 Gyro (Rate) L3GD20H MAX21000 $13$3.18 $2.92 MagHMC5883L MAG3110 $10 $15 $1.55 $0.78 IMUL3GD20H+LM303 LSM9DS0 MPU-9150** $20 $35 $3.18 + 1.76 $5.32 $7.12

33. Links and books  Embedded.fm episodes:  9 (Kidnapped and Blindfolded) 9  43 (A Lot of High-Falutin’ Math) 43  Adafruit 9DOF code (github)github  Hackaday.io/elecia for North Star IMU light example Hackaday.io/elecia

34. Elecia White @logicalelegance Thank you! Questions?