Whate are the basic concepts for implementing anti-shock and anti-shake algorithms?

Question

I have some animations happening upon fine acceleration detections. But when the user sits in a car or is walking it may get annoying.

Basically, all that stuff has to be disabled automatically as soon as there is too much vibration or shaking. Conceptually, I think that it's very hard to filter those vibrations out , since the "vibration phase" changes permanently. I woul define "unwanted vibration or shocks" as acceleration values that change very fast by an large interval of values, or, an permanently changing accumulated value that does not exceed an specified treshold range in an specified minimum period of time.

I am looking for "proven" concepts, before I start reinventing the wheel for a couple of days.

Answer 1

I don't have any concrete answers for you, but you might want to Google band-pass filters or anti-aliasing filters for some ideas on how to approach this. Basically, if you can identify the frequency range of accelerations that you want to consider real, you can filter out frequencies that fall outside this range.

Answer 2

Before you start doing too much pre-optimization, I think you should implement a low pass filter and see if that does the job. Most iPhone apps effectively use a variation of an LPF to get rid of unwanted accelerometer noise.

You could also go the other way and use a high pass filter. Once you get a certain power level passing through the HPF, stop processing data.