The composed correcting Kalman filtering method for integrated SINS / GPS navigation system

Inertial navigation system, as one kind of widely used autonomous navigation system can supply not only continuous vehicle position and velocity information but also three axes attitude. SINS navigation errors will dramatically increase with time. So, SINS cannot work for a long time by itself to meet demand of accurate navigation. GPS can provide accurate positioning and velocity information and its errors will not accumulate with time. By integrating the merits of GPS and SINS, GPS/SINS integrated navigation system will improve navigation accuracy and reliability. Different correcting methods of Kalman filter for deep integration of pseudo range with strapdown inertial navigation system are investigated in this paper. On the base of analyzing navigation errors, a composed correcting Kalman filter for GPS/SINS integrated navigation system is proposed by combining output correcting method and feedback correcting method. Compared with the two correcting methods, the composed correcting method improves the integration system navigation accuracy. The simulation results show the efficiency of this composed correcting Kalman filter.