Analysis of the Effect of Slow-Varying Errors on Rotary Modulation Systems

Abstract

Rotation modulation is a technique that relies on the specific rotation of an inertial measurement unit (IMU) to achieve the self-compensation of device errors. Common rotation schemes are classified into two modes: continuous rotation and a rotation–stop combination. Aiming at the problem of the poor modulation of slow-varying errors in the rotation–stop combination mode, a detailed analysis is conducted on the modulation effects of slow-varying errors in three schemes employing different rotation modes. Firstly, a detailed mathematical analysis is performed on the influence of gyro slow-varying drifts on two rotation modes, and the analysis results are validated through simulations. Subsequently, simulation experiments are conducted on three schemes to analyze their modulation effects on the slow-varying errors of inertial devices. The simulation results reveal that the modified dual-axis rotation scheme exhibits superior modulation effects on the slow-varying errors of inertial devices compared to the dual-axis sixteen-position rotation scheme and the multi-axis alternating continuous rotation scheme.