Maximum correntropy delay Kalman filter for SINS/USBL integrated navigation

Communication delay and non-Gaussian noise are challenging issues for underwater navigation and positioning. This study proposes a filtering algorithm for strapdown inertial navigation system/ultra-short baseline (SINS/USBL) integrated navigation to deal with time-varying delay in underwater acoustic communication and cope with non-Gaussian noise induced by outliers and measurement noises. Considering the influence of platform error angle, the measurement equation of SINS/USBL is derived. According to the distance-related time delay characteristics of USBL acoustic communication, the delay system model is obtained based on state inversion. A linear recursive model based on a delay system model is constructed to update the posterior estimation and covariance matrix by combining it with the maximum correntropy criterion. The algorithm solves the problems of communication delay and non-Gaussian noise and greatly reduces the computational complexity due to its adaptive adjustment function. Simulation and experimental results verify the filter's improved accuracy and robustness.