基于ZIHR航向角修正方法的行人导航算法

在行人导航系统中,零速修正(zero velocity update, ZUPT)方法能够准确计算出速度误差和水平姿态角误差,但是航向角误差却因其不可观难以估计而极易发散。为了解决航向角误差极易发散的问题,提出了零积分航向角速率(zero integrated heading rate, ZIHR)修正方法。推导发现在零速状态下相邻航向角差值和陀螺的漂移及航向角误差存在一定的关系,将此差值作为量测值,在ZUPT的基础上扩展一维量测,将卡尔曼滤波得到的估计值进行反馈校正。通过多组微机电系统(micro-electro mechanical system, MEMS)实物实验验证:提出的ZIHR修正方法能够很好地解决MEMS 惯性器件漂移导致的误差累积问题,多组实验的定位误差均小于总行程的2%。

Pedestrian navigation algorithm based on ZIHR heading angle correction method

In pedestrian navigation system, zero velocity update (ZUPT) can estimate the velocity errors and horizontal attitude errors. However, good heading error estimation for such a system remains a challenge, this is due to the unobservability of heading error. In order to solve the problem of easily divergent heading error, zero integrated heading rate (ZIHR) correction method is proposed. The heading angle difference at adjacent time has a certain relationship with the drift of the gyro and heading error angle. The difference is taken as the measurement value and one-dimensional measurement is extended on the basis of ZUPT. The errors which are estimated by Kalman filter are fed back to original navigation system. In the end, multiple sets of physical experiment results show that the ZIHR correction method can efficiently reduce the drift errors of the micro-electro- mechanical system inertial sensors, and the position accuracy can reach 2% of travel distance.