Research on MIMU/BD integrated navigation with three-axis magnetometer aided

Integration is a current trend in navigation system research. MIMU (Micro Inertial Measurement Unit) is compact, cheap, low-power, and highly reliable. BD (BeiDou System) is a satellite navigation system with our own independent intellectual property right. Integrating MIMU with BD can lessen MIMU´s error accumulation and BD´s low robustness, thus making MIMU/BD an ideal integrated navigation system. However, MIMU/BD has poor heading error observability. A three-axis magnetometer (TAM) can measure earth´s magnetic field to obtain carrier heading. This paper focuses on improving heading accuracy of MIMU/BD integrated navigation system with TAM aided. TAMs are used to calculate the heading angle. Calibrating TAMs using a RLS algorithm with a forgetting factor is introduced. An integrated navigation algorithm based on Kalman Filter is used. Vehicle experiments show that this method efficiently improves the heading accuracy.