A System-Level Calibration Method for INS: Simultaneous Compensation of Accelerometer Asymmetric Errors and Second-Order Temperature-Related Errors

Inertial navigation systems (INSs) can continuously provide the attitude, velocity, and position of the vehicle with high accuracy. However, the accelerometer scale factor asymmetry and the temperature-related accelerometer errors can cause significant navigation errors. To solve this problem, in this article, a novel system-level calibration method is proposed, which achieves simultaneous compensation of accelerometer asymmetric errors and second-order temperature-related errors. First, the error model including accelerometer asymmetry and temperature-related errors is constructed. Then, a 51-D Kalman filter is applied to estimate all error factors of accelerometers including biases, scale factor errors, installation errors, scale factor asymmetry, and first- and second-order temperature-related error coefficients at the same time. The effectiveness of the calibration method is proved by both simulation and experiment. The pure inertial navigation experiment results illustrated that, compared with the traditional 30-D calibration, our method can reduce the root mean squares of radial position error and radial velocity error by 50% and 39%, respectively, which indicates that the proposed method can be used to improve the navigation performance of ground or aerial vehicles.