An Improved Robust Filter Method for SINS/DVL System with Earth Frame Error Model

In view of the poor robustness of the integrated navigation system based on SINS/DVL in complex environments, an improved robust filter method for SINS/DVL system with earth frame error model is proposed in this paper. On the one hand, based on the traditional navigation frame SINS/DVL navigation system, a system mechanization for the strap-down inertial navigation algorithm and an integrated navigation algorithm based on the earth frame error model are designed. This method realizes the SINS/DVL integrated navigation method under the earth frame error model by recursively recursing the state equation of the earth frame, the measurement equation and the conversion between the earth frame and the navigation frame. On the other hand, based on the Huber M filter algorithm, an improved robust filter algorithm is proposed. The algorithm combines chi-square detection for pre-judgment, and introduces the backward Kalman filter algorithm. The improved algorithm can suppress the influence of continuous non-Gaussian strong noise and improve the filtering accuracy and stability. Finally, the validity of the method proposed in this paper is verified by the simulation and lake test.