Orientation Estimation for Motion Capture Unit with Significant Motion Interference

Abstract

The orientation estimation is a critical technique in inertial sensor based motion capture systems. One challenge of the orientation estimation is that it suffers from the acceleration interference due to body segment motion, especially when the acceleration interference is significant. In this paper, we propose a quaternion based orientation estimation algorithm using unscented Kalman filter. In the algorithm, the acceleration interference is taken as an element of the state vector and estimated in the algorithm together with the orientation quaternion, knowing that the acceleration interference can be predicted based on the rotational angular velocity. The experiments were conducted using both computer simulation and in real-world motion scenarios. Both experimental results have shown the effectiveness of the proposed orientation estimation algorithm.