title: How to measure the speed of car by phone with accelerometer and gyroscope?
body: <p>I want to know current speed of car and make a passed path. I have an Android phone with accelerometer and gyroscope which sent me data. This is the data in phone system of coordinate that probably wouldn't the same as coordiante system of car. </p>
  
  <p>How I can transform this accelerations and rotations to car system of coordinate?</p>