Attitude Calculation of AHRS Based on Geomagnetic Field Adaptive Correction

基于地磁场自适应修正的航姿系统姿态解算研究

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

Received: 5 March 2018

Abstract

In the attitude and heading reference system (AHRS), the output noise of MEMS gyroscope is too large, zero drift can not be eliminated completely, and the output of angular rate is easy to be interfered, which leads to low accuracy and large accumulated error of attitude quaternion and so on. In this paper, an adaptive extended Kalman filter algorithm is proposed based on the information of geophysical field (earth gravity field and geomagnetic field) to continuously and adaptively correct the accumulated error of MEMS gyroscope in attitude calculation. The experimental results via ROS robot platform show that the proposed algorithm can effectively solve the problem of large accumulated error in the process of attitude quaternion solution, and improve the accuracy of attitude calculation, thus the effectiveness of the proposed algorithm is verified.

摘要

针对航姿参考系统（attitude and heading reference system，AHRS）中，MEMS陀螺仪输出噪声过大、零点漂移无法完全消除、角速率输出易受干扰等导致的姿态四元数精度低、累积误差较大等问题，提出了一种自适应扩展卡尔曼滤波算法，利用地球物理场（地球重力场、地磁场）信息不断自适应修正MEMS陀螺仪在姿态解算过程中的累积误差。在ROS机器人平台上进行了实验，实验结果表明该算法能有效解决在求解姿态四元数过程中累积误差较大的问题，同时可以提高姿态解算精度，进而验证了该算法的有效性。