Accuracy Improvement of a Redundant Inertial Measurement Unit Brought about by the Dual-Axis Rotational Motion

Abstract

The inertial measurement unit (IMU) can achieve high reliability by configuring redundant sensors. However, the improvement in navigation accuracy of the redundant inertial measurement unit (RIMU) is minor. To achieve high accuracy and high reliability of the inertial navigation system (INS), a novel method to control dual-axis rotation of the RIMU to compensate its errors is proposed in this paper. First, a general error model of RIMU which can be applied to various sensor configurations is established. Second, the dual-axis turntable in INS is controlled to make the RIMU rotate periodically which can compensate the errors and improve the navigation accuracy. However, the effect of error compensation by rotation will be reduced when the vehicle is in angular motion, so a method of dual-axis rotational motion based on navigation frame which can alleviate the negative effect caused by the angular motion of vehicle is proposed. Simulation results show that the proposed method can greatly improve the navigation accuracy whether the vehicle is in angular motion or not.