An Improved System-Level Calibration Method of Strapdown Inertial Navigation System Based on Matrix Factorization

This paper develops an improved system-level calibration method for the strapdown inertial navigation system (SINS). It solves the problems of too many dimensions of state variables and installation error matrix coupling. To solve the two problems, the improved system-level calibration method derives the physical causes of the installation error matrix. The installation error matrix is decomposed into skew symmetric matrix and symmetric matrix. Then the appropriate system-level calibration scheme is designed based on the velocity error equations and attitude error equations. The designed system-level calibration scheme separates the coupled installation error matrix parameters by changing the value of strapdown matrix. Simulation results demonstrate that the proposed method is feasible. The relative errors of gyro calibration parameters are between 0.03% and 0.70%, and the relative errors of accelerometer calibration parameters are between 0.01% and 0.24%. For comparison, the navigation and positioning experiments are also performed to evaluate the proposed method. The results indicate that the improved system-level calibration scheme is better than the traditional system-level calibration scheme. The positioning error is reduced by more than 30%.