APPARATUSES AND METHODS FOR MAGNETOMETER ALIGNMENT CALIBRATION WITHOUT PRIOR KNOWLEDGE OF THE LOCAL MAGNETIC FIELD

摘要

Apparatuses and methods calibrate attitude dependent magnetometer alignment parameters of a magnetometer mounted together with other angular position sensors on a device without prior knowledge of the local magnetic field and allowing a constant but unknown offset of the yaw angle in the reference attitudes with respect to an earth-fixed coordinate system. The method includes acquiring magnetic field measurements from the magnetometer and corresponding estimated angular positions subject to an unknown yaw offset relative to a gravitational reference system. The method further includes iteratively computing a scale and vector components of a quaternion representing a misalignment matrix, an inclination angle of local magnetic field, and a yaw angle offset, using an extended Kalman filter (EKF) infrastructure with a specific designed model and constraints, based on the magnetic field measurements and the corresponding estimated angular positions.