01-18-2020, 02:19 AM

I hope this experiment has not already been discussed. It's finding the location of the accelerometer inside a phone by placing the phone on a turntable and recording the accelerometer readings while the turntable is rotating. Combined with the phones position relative to the spindle (rotation center) and the turntable rotation speed, the location of the accelerometer can be calculated. To simply the calculations the middle right side of the phone was placed adjacent to the spindle with the z axis pointing up.

The first plot shows a run with accelerometer and gyro Wz data recorded.

It's noted that the accelerometer Ax and Ay show bias terms of -0.27 and 0.085 m/s^2 respectively.

The second plot shows a different run with linear acceleration and gyro Wz data recorded.

The linear acceleration Ax and Ay do not show bias terms but overshoot zero as the turntable is slowing down.

Both runs start with the turntable stationary then the turntable is turned on and speeds up to 45 RPM. The turntable is then turned off and slows down to a stop.

The first plot shows a run with accelerometer and gyro Wz data recorded.

It's noted that the accelerometer Ax and Ay show bias terms of -0.27 and 0.085 m/s^2 respectively.

The second plot shows a different run with linear acceleration and gyro Wz data recorded.

The linear acceleration Ax and Ay do not show bias terms but overshoot zero as the turntable is slowing down.

Both runs start with the turntable stationary then the turntable is turned on and speeds up to 45 RPM. The turntable is then turned off and slows down to a stop.