Attitude Calculation Based on Sequential Correction of Gravity Field and Geomagnetic Field

基于重力场与地磁场序贯修正的姿态解算研究

School of Marine Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China

Received: 13 March 2019

Abstract

Aiming at the problems of gyroscope error divergence and magnetometer susceptibility to soft magnetic environment in attitude calculation of unmanned system, a method of attitude calculation based on gravity field and geomagnetic field sequential correction is proposed. In this method, gyroscope output is used to construct the state equation of attitude quaternion, and then the quaternion is sequentially corrected twice by using accelerometer and magnetometer data in order to obtain accurate attitude output. The experimental results show that, compared with the three traditional attitude calculation algorithms, this algorithm can effectively suppress the gyroscope drift error and improve the attitude output accuracy under the environment of magnetic interference. The static accuracy of the attitude angle is not greater than that of the dynamic accuracy, which meets the application requirements of the unmanned system.

摘要

针对无人系统姿态解算中存在陀螺仪误差发散快、磁力计易受软磁环境干扰等问题，提出了一种基于重力场与地磁场序贯修正的姿态解算方法。该方法采用陀螺仪输出构建姿态四元数的状态方程，然后依次利用加速度计与磁力计数据对四元数进行2次序贯修正，以获得姿态的准确输出。实验结果表明，相比传统的2种姿态解算算法，新算法能有效抑制陀螺仪的漂移误差，提高磁干扰环境下的姿态输出精度，其姿态角的静态精度不大于0.5°，动态精度优于2°。