Detection and Mitigation of Errors on an Ultra-Tight Integration System Based on Integrity Monitoring Method

The integrity monitoring of integrated GNSS/INS navigation systems has been developed since it can monitor GNSS failures with less visible satellite. However, it is limited to find the error sources and mitigate the errors. Hence, a novel integrity monitoring algorithm which detects the pseudorange and pseudorange rate residuals from every tracking loop is proposed in this paper to monitor GNSS failures and determine the faulty tracking channel. Then, this algorithm is employed in the ultra-tightly integrated GNSS/INS navigation system to detect step errors and slowly growing errors caused by different interferences. After the faulty channel is determined, an error mitigation method is designed by adjusting the measurements of the integration Kalman filter to eliminate the effect of faulty satellite on the ultra-tightly integrated navigation. Finally, a high dynamic scenario including step errors and slowly growing errors is simulated by a GNSS signal simulator and some experiments are performed to prove the effectiveness and reasonableness of the detection and mitigation method.