基于三分量地磁滤波技术的微型AHRS算法研究

Micro AHRS algorithm based on three-component geomagnetic filtering technology

针对常规的微型姿态参照系统(AHRS)算法存在过载干扰和滤波发散的问题,设计了一种基于三分量地磁滤波技术的微型AHRS算法。采用一种简化的Sage-Husa自适应滤波算法进行了AHRS的信息融合;采用姿态误差角和陀螺漂移作为状态变量,进行了自适应滤波的时间更新,采用三分量地磁矢量作为观测量,进行了自适应滤波的量测更新;最后,对该算法进行了半物理仿真实验。实验结果表明,该算法能够有效地减小高过载造成的姿态测量误差,在2 g线振动测试条件下,该算法的俯仰角和横滚角的测量精度优于0.75°,航向角精度优于1.87°;与常规的算法相比,系统的抗过载能力提高了近3.2倍。该算法测量精度高、抗过载性好,具有很强的自适应能力,尤其适用于低铁磁干扰、高过载的工作环境。

Aiming at overload interference and fihering divergence of common micro attitude heading reference system （AHRS） algorithms, a micro AHRS algorithm based on three-component geomagnetic filtering was proposed, which adopted a simplified Sage- Husa adaptive filter. Then, attitude errors and gyros＇s drifts were chosen as the states of the AHRS system, and the three-component geomagnetic vector from three-axis magnetometer was taken to construct the measurements. The adaptive filtering was used to estimate errors of AHRS. Finally, AHRS semi-physical simulation was done. Simulation results show that, this algorithm can reduce the overload interference effectively. Under the testing condition of 2 g random vibration, attitude errors are less than 0.75°, heading error is less than 1.87°, the system measurement precision is improved almost by 3.2 times. The new algorithm improves the accuracy, anti-overload property and adaptability. This algorithm is particularly suitabler for the work environment with low ferromagnetic interference and high overload.