GPS/INS/speed log integrated navigation system based on MAKF and priori velocity information

The accuracy of GPS/INS integrated navigation system will decline when GPS is disturbed or outages occur. In order to solve this problem, a GPS/INS/Speed Log integrated navigation system based on measurement-based adaptive Kalman filtering algorithm (MAKF) and priori velocity information is put forward. MAKF uses the short-term high-precision feature of INS to get the adaptive estimation of GPS measurement noises and modify the observation error covariance. When GPS outages occur, the navigation system will work in INS/Speed Log integrated mode, meanwhile it takes advantages of priori velocity information to improve the observability of system. The simulation results confirm that this system is superior to the improved Sage-Husa adaptive filtering algorithm in filtering precision and stability when GPS measurement noises are changing. And it has a much better performance than INS works alone during GPS outages.