# Circular motion experiment using accelerometer and gyroscope

1. May 30, 2012

### epyd

Hi all,

Currently, I'm doing an experiment to estimate length of a rigid body.
The approach is based on information from accelerometer and gyroscope while the rigid body is moved in circular way.

The relationship is: v = ω x R (all are vectors, and 'x' means cross products)

v = tangential velocity
ω = angular velocity (gyroscope output)
R = vector of the rigid body

However, I am confused about the 'v' (tangential velocity). I was trying to calculate it by integrating accelerometer output. But, as we know, in accelerometer's output we have to information, gravity and linear acceleration.

It is easy to remove the gravity from accelerometer output, if the orientation of accelerometer does not change. But, how can we remove the gravity when the orientation of accelerometer changes over the time ?

Is it possible to calculate tangential velocity using accelerometer?

Thank you

2. Jun 2, 2012

### ralqs

I'm sorry, but it's very difficult to understand your experimental setup with the description you gave.