Optimization of Reliability-Centered Inertial Navigation System by the Redundancy Reuse Technology

The redundant navigation system is widely utilized in missile systems due to its high precision, high reliability, and low maintenance requirements. Still, one of the main challenges is how to fully exploit redundant resources instead of just depending on fault isolation. Conventional approaches underutilize redundant resources by separating redundant systems into two subsystems or by employing the simple least-squares fitting method for inertial solution. In this study, inspired by the multiple sensitive axis characteristics of the redundant navigation system, multiple coordinate systems are constructed. By analyzing the characteristics of these coordinate systems under different operating conditions, the performance of the missile-borne inertial navigation system is further enhanced. In addition, a selection and reconstruction method for multiple coordinate systems based on the Huber loss algorithm is proposed, and the Huber loss parameter can be adaptively determined according to sensor calibration accuracy. The coordinate is reconstructed between a three-axis coordinate system with minimum absolute value and a multiaxis coordinate system with minimum variance. The semi-physical experiment results demonstrate that the proposed method improves the calibration performance significantly. Specifically, the calibration accuracy of the gyro bias error is improved from 23.3 % to 83.3 %, while the bias calibration accuracies of e-acc and f-acc are improved by 41 % and 59 % respectively.