Eliminating the Effect of Magnetic Disturbances on the Inclination Estimates of Inertial Sensors * *This work was conducted within the research project BeMobil, which is supported by the German Federal Ministry of Research and Education (FKZ 16SV7069K).

Abstract

Abstract Inertial measurement units (IMUs) are a promising tool for realtime analysis of human motion in many application domains. We consider the standard sensor fusion problem in IMU orientation estimation. We highlight the malicious effects that inhomogeneous magnetic fields, which are often found in indoor environments, can have on the inclination portions (roll and pitch) of the orientation estimate. We then propose a novel method that uses an analytical solution of the sensor fusion problem and purely horizontal magnetometer-based corrections. The method assures that magnetic field measurements affect only the heading (yaw) component of the orientation estimate. Furthermore, we parametrize the algorithm such that the user can choose the time constant and aggressiveness with which the algorithm balances between gyroscope drift compensation and rejection of disturbances caused by inhomogeneous magnetic fields or by velocity changes.