Study on Strapdown Inertial Navigation Systematic Redundancy(II)

To improve the navigation accuracy of strapdown inertial navigation system (SINS) in long time flying, the three general errors of attitude, velocity and station and system error were analyzed in this paper. The state equation and error analysis of SINS combined with globe positioning system (GPS) and Doppler navigation system (DNS) were also presented. The simulation in certain condition was made. On this base, the principle and method of fault inspection and isolation for the subsystem in SINS/GPS and SINS/DNS combined system by the residual error χ~2 and state χ~2 error inspection method. The simulation for fault tolerant combined navigation system was made using residual error χ~2 inspection. The results showed that SINS/GPS and SINS/DNS could improve navigation accuracy, and the faulted subsystem could be determined and isolated by residual error χ~2 inspection.