Calibration of a Redundant IMU

Abstract

A calibration technique for a redundant IMU is proposed. The conventional orthogonal IMU with three gyros and three accelerometers may cause the enormous navigation error even if one sensor fault occurs. In order to overcome this problem, the redundant IMU is constructed by configuring redundant sensors. The redundant IMU has a merit that it can detect and isolate the faults. So far, the sensor configurations and FDI techniques have been investigated. However, the research on the calibration of the redundant IMU has not been carried out. In this paper, three coordinate frames in the redundant IMU are defined and the IMU error is modeled based on the frames to establish a calibration procedure for the redundant IMU. A technique for estimating the error coefficients of accelerometers and gyros is proposed. And a test procedure of the 2-axis turntable for the cone configuration IMU is presented. Finally, a redundant IMU with cone configuration is implemented and the performance of the proposed technique is verified by some experiments.