High-Precision Calibration Scheme for RIMU

Abstract

Due to the diversity of redundant configuration schemes, the existing calibration algorithm for the redundant inertial measurement unit (RIMU) cannot be applied generally. In addition, the linearized calibration model utilized in the traditional calibration algorithms also leads to low calibration accuracy. In this paper, a high-precision calibration scheme is proposed for the RIMU, which can be applied generally. At first, a general calibration model for the RIMU is established. Then, a zero-space amplification algorithm is applied to improve the observability of the system. At last, the extended Kalman filter (EKF) based on the second-order Taylor series expansion is proposed, which can estimate the biases, scale factor errors, and installation errors simultaneously. The simulation and experimental results demonstrate that the proposed calibration algorithm calibrates the system accurately and improves the performance of the RIMU effectively. Furthermore, the proposed algorithm can be applied generally in all kinds of RIMU.