How to obtain only linear acceleration from accelerometer using gyroscope?

Question

I have a small remote controlled car going on the room floor. For simplicity let us assume it is moving along say x-axis. Now, the floor seems flat but there are very minute

Answer 1

I have implemented sensor fusion for the Shimmer platform based on this manuscript, it's basically a tutorial:

Direction Cosine Matrix IMU: Theory

This manuscript pretty much answers your question.

These have also been a big help:

An introduction to inertial navigation

An Introduction to the Kalman Filter

Pedestrian Localisation for Indoor Environments

Combine Gyroscope and Accelerometer Data

Just promise me you won't try double integrating the linear acceleration because it won't work and I suspect that it is what you are trying to do.