Track small iphone movements without GPS

Question

I need to write an iphone application that tracks the movement of the iphone itself, given its initial position, without using GPS. That is, I can only use the data provided by the gyroscope and accelerometer. The distance I need to measure is pretty small, and the accuracy I'm looking for is a maximum of 40-50 cm (~ 2 feet).

Is it possible? If so, what is the best way to do this? In addition, do you know about existing (and possibly open sources) projects that have already implemented this?

Thank you so much!

Answer 1

If you integrate acceleration twice, you get a position, but the error is terrible. In practice, this is useless.

Here is an explanation of why (Google Tech Talk) at 23:20. I highly recommend this video.

I answered a similar question here and here .