基于地磁序列匹配的大型室内动态定位方法

基于地磁信号的定位技术无需架设信号发送设备,成本低且可覆盖室内定位范围广。针对室内地磁定位方法采集工作繁琐复杂需反复测量才能精准映射二维平面坐标点的现状,提出一种基于移动终端图像可视化映射和自动插入采集数据的方法,快速采集室内地磁指纹,动态建立匹配室内二维地图的指纹数据库。在此基础上,定位阶段使用改进的动态时间规整(DTW)算法进行地磁序列匹配,提高大型数据库的动态定位效率。后续采用粒子滤波算法融合地磁序列定位和行人航位推算(PDR)的结果,在智能移动终端载体上实现快速精准定位。实验结果表明该动态定位方法在大型室内区域的动态实时跟踪定位效率为每步65 ms,平均定位精度为1.4 m以内。

Large indoor dynamic positioning method based on magnetic sequence matching

Positioning technology based on geomagnetic signal has the advantages of no need to set up signal transmitting equipment, low cost and wide coverage of indoor positioning. Aiming at the present situation that indoor geomagnetic positioning method is complicated and requires repeated measurement to accurately map two-dimensional plane coordinate points, a method based on mobile terminal image visualization mapping and automatic insertion of acquisition data was proposed to quickly collect indoor geomagnetic fingerprints and dynamically establish fingerprint database matching indoor two-dimensional maps. Based on this acquisition method, the improved dynamic time warping (DTW) algorithm is used for geomagnetic sequence matching in the positioning phase, which can reduce the amount of calculation and improve the accuracy of positioning results. Subsequently, particle filter is used to fuse the positioning results based on geomagnetic sequence matching and pedestrian dead reckoning (PDR) results to achieve fast and accurate positioning on the intelligent mobile terminal carrier. Simulation and experimental results show that the proposed method has a pedestrian tracking and positioning efficiency of 65 ms per step and an average positioning accuracy of 1. 4 m in large indoor areas.