Consistency Monitoring for Spacecraft Attitude Estimators

In this paper, a novel consistency monitoring method is proposed for spacecraft attitude estimator. The method allows for consistent evaluation of the estimator as a key index to determine whether the estimators are running normally. Compared with the theoretical consistency monitoring method, the proposed method replaces the true state with the prior state estimates, which can avoid the problem that true states cannot be obtained accurately. Then, the consistency monitoring method can be embedded into the attitude estimator as a block, and work in the state-space domain directly. Moreover, the probability of false alert specified by the required index can be used as a threshold, and the user interaction is avoided. The performance of the proposed method is tested and analyzed by simulations in several cases, and the results indicate that the method can detect the inconsistent estimate accurately.