A quaternion-based sensor fusion approach using orthogonal observations from 9D inertial and magnetic information

Abstract

The micro-electro-mechanical technology facilitates the development of low-cost orientation estimation solutions using inertial and magnetic sensors. However, the magnetic disturbances challenge the robust pitch and roll measurements on some occasions, such as the quadrotor, ship, and railway. This work analyzes the coupling mechanism of the magnetic information on the roll and pitch estimates. Subsequently, it proposes a quaternion-based decoupled sensor fusion approach under the frame of an extended Kalman filter by taking the orthogonal gravitational vector and horizontal magnetic vector as absolute observation references. Three experimental tests validated its performances in robust roll and pitch measurements under magnetic disturbances, static and dynamic robotic motion estimation, and human upper body pose tracking. Results show that the proposed sensor fusion approach could keep the roll and pitch immune to the magnetic disturbances, and provide reliable static and dynamic orientation estimation accuracy. Moreover, it is promising to provide feedback for rehabilitation training.