基于函数拟合姿态更新方法的足绑式行人导航算法

Foot mounted pedestrian navigation algorithm based on the function fitting attitude update algorithm

针对低成本足绑式行人导航系统中航向误差快速发散导致定位精度下降的问题,从降低姿态更新误差的角度出发,基于等效旋转矢量理论和傅里叶展开,提出一种基于函数拟合姿态更新方法的足绑式行人导航算法。首先,以等效旋转矢量法为理论基础,使用正余弦函数拟合足部运动角速度,利用泰勒展开及等式变换求取函数拟合姿态更新方法;随后,结合长短期记忆网络(LSTM)零速检测,设计适用于多种步态的足绑式行人导航算法;最后,以WT901BC IMU为硬件平台开展了多组不同步态的闭环路径验证实验,结果表明,相较于传统基于四元数法或二子样等效旋转矢量法的足绑式行人导航算法,所提方法定位误差平均减小47.66%和42.83%,航向误差平均减小49.99%和44.74%。

To address the problem that the positioning accuracy is reduced due to the rapid divergence of heading error in the low-cost foot-mounted pedestrian navigation system,from the perspective of reducing the attitude update error,based on the equivalent rotation vector theory and Fourier expansion,a foot-mounted pedestrian navigation algorithm based on the function fitting attitude update algorithm is proposed.Firstly,based on the equivalent rotation vector method,the sine and cosine functions are used to fit the angular velocity of the foot motion.The Taylor expansion and equation transformation are used to obtain the function fitting the attitude update method.Then,combined with the long short-term memory network(LSTM)zero velocity detection method,a foot-mounted pedestrian navigation algorithm suitable for a variety of gait is designed.Finally,WT901BC IMU is used as the hardware platform to carry out the verification experimental of multiple sets of closed-loop paths in different gaits,and the results show that,compared with the traditional foot-mounted pedestrian navigation algorithm based on the quaternion method or the two subsamples equivalent rotation vector method,the positioning error of the proposed method is reduced by 47.66% and 42.83% on average,and the heading error is reduced by 49.99% and 44.74% on average.