Abstract:

In order to solve the problem that the performance of shipborne strapdown inertial navigation system (SINS) transfer alignment is affected by the system dynamic model and noise statistical properties, a new algorithm of “velocity+attitude” transfer alignment based on modified adaptive filter is put forward. In order to solve the problem of filtering divergence caused by noise matrix positive semidefinite, the iterative formulas of the adaptive filtering noise matrix are modified and a strategy to restrain filter divergence based on covariance matching technique is put forward. According to the problem that the dynamic model is affected by the carrier deformation during ship sailing, installation error angle and deflection deformation angle are added into the state and compensated in the algorithm. Computer simulation shows that the modified algorithm can estimate attitude misalignment angle and installation error angle in 50 seconds effectively, and achieve shipborne SINS transfer alignment rapidly.