I haven't performed any tests, but if I am in a train with velocity != 0, what will measure my IMU? (With IMU I suppose to have acc + gyr + magn).

I am in a relative motion system, and my MEMS will measure the acceleration with respect to the train measurement system or with respect to the earth measurement system?


closed as off-topic by Scott Seidman, Daniel Grillo, Matt Young, Neil_UK, Dave Tweed Apr 20 '16 at 18:04

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  • \$\begingroup\$ The IMU doesn't know about the train. If you are in a train with a constant velocity, the only acceleration is g, downwards. If the train accelerates or deaccelerates, your IMU will measure that. \$\endgroup\$ – uint128_t Apr 20 '16 at 16:39
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    \$\begingroup\$ I'm voting to close this question as off-topic because this is physics \$\endgroup\$ – Scott Seidman Apr 20 '16 at 16:51
  • \$\begingroup\$ Agreed @ScottSeidman. This is an intro physics question. \$\endgroup\$ – Daniel Apr 20 '16 at 17:21

You would need to integrate the acc from standstill to movement down to deceleration. I did similar experiment on sportsman, but the final result was such that it is impossible to get the velocity, but it was quite precise to compute the velocities for small movements like gait movement up/down. This was done such that DC component was removed by means of moving average filter and only AC signal was integrated.

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    \$\begingroup\$ Thank you for your answer :) U always give nice answers! \$\endgroup\$ – Enrico123 Apr 21 '16 at 6:26
  • \$\begingroup\$ @Enrico123 Nice to hear from you. \$\endgroup\$ – Marko Buršič Apr 21 '16 at 10:39

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