摘要
在基于惯性传感器的室内人员自主定位系统中,由于陀螺仪存在随时间增长的漂移,需要依靠地磁场对航向校正。然而,室内场景中地磁场会受到比较严重的干扰,磁力计自身也存在一定误差,严重影响了地磁场辅助定位的航向校正效果。该文提出一种地磁辅助的室内定位航向校正方法,该方法首先结合人体运动模型对磁力计进行校准,获取相关校准系数,提高磁力计解算航向精度。在此基础上利用改进的磁场准静态检测方法提取可用的磁力计观测量,经校准系数校准后结合零速更新算法(Zero velocity UPda Te,ZUPT)辅助的扩展卡尔曼滤波(Extended Kalman Filter,EKF),对陀螺仪航向进行滤波校正。实验结果显示在长约684 m的轨迹下航向误差仅为3.2°定位误差小于0.5 m,定位精度优于0.2%,验证了该方法较传统的磁场辅助航向校正方法的优越性。
In inertial based self-contained pedestrian positioning systems, because the drifts of the gyroscopes grow with time, it relies on the earth magnetic field to suppress the heading errors. However, the earth magnetic field suffers from severe interference in indoor scenarios, and the magnetometer itself has measurement errors, the above reasons have dramatically limited the performance of the magnetometer-aided heading error calibration. This paper proposes a magnetic-aided heading error calibration approach. Firstly, the magnetometer is calibrated according to the motion model of the pedestrian and the calibration coefficients obtained are used to improve the accuracy of heading derived by the magnetometer. On this basis, a proved Quasi-Static magnetic Field（QSF） detection approach is proposed to extract the usable magnetic information fed into Zero velocity UPda Te（ZUPT）-aided Extended Kalman Filter（EKF） algorithm to conduct the heading calibration. The experiment results show that the 684 meter long walk only has a position error of less than 0.5 meter and heading error of 3.2 degrees, and the position error is less than 0.2% of the total walking distance. The results indicate that the performance of the proposed method is superior to the existing approach.
出处
《电子与信息学报》
EI
CSCD
北大核心
2017年第3期647-653,共7页
Journal of Electronics & Information Technology
关键词
室内行人定位
磁场准静态检测
航向校正
磁力计校准
Indoor pedestrian positioning
Quasi-static magnetic field detector
Heading calibration
Magnetometer calibration
