how to calculate phone's movement in the vertical direction from rest?

Question

I am developing an app using android OS for which I need to know how can I calculate the movement of the device up in the vertical direction.

For example, the device is at rest (point A), the user picks it up in his hand (point B), now there is a height change between point A and point B, how would i calculate that?

I have already gone through the articles about sensors and accelerometers, but I couldn't really find anything to help me with that. Anyone have any ideas?

Answer 1

If you integrate the acceleration twice you get position but the error is horrible. It is useless in practice. Here is an explanation why (Google Tech Talk) at 23:20. I highly recommend this video.

Now, you do not need anything accurate and that is a different story. The linear acceleration is available after sensor fusion, as described in the video. See Sensor.TYPE_LINEAR_ACCELERATION at SensorEvent. I would first try a high-pass filter to detect sudden increase in the linear acceleration along the vertical axis.

I have no idea whether it is good for your application.