SINS/SAR/GPS navigation system intelligent fault diagnosis method

Residual chi-square test is not sensitive to soft faults and also can´t detect suddenly changing faults well in inaccurate observation noise, therefore, an intelligent fault diagnosis method of residual chi-square test assisted by fuzzy adaptive filter is proposed to slove the problem. To deal with the soft fault, a fuzzy adaptive filtering algorithm is proposed. By monitoring the residual and the residual rate, the observation quality gene is obtained by the fuzzy logic control system. The local filter is adaptively adjusted on-line, and the filtering divergence arising from the gradual changing fault is prevented, and then the residual chi-square test is assisted to detect faults. Simulation results show that the proposed method can effectively diagnose suddenly changing faults and soft faults online, and ensure system precision during failure phase, and the system reliability is improved.