一种穿戴式多IMU的航向对齐方法  

A heading alignment method for multiple wearable IMUs

作　　者：夏大洲 姜卫平[2] 旷俭 牛小骥[2] XIA Dazhou;JIANG Weiping;KUANG Jian;NIU Xiaoji(School of Geodesy and Geomatics,Wuhan University,Wuhan 430079,China;Research Center of GNSS,Wuhan University,Wuhan 430079,China)

机构地区：[1]武汉大学测绘学院,武汉430079 [2]武汉大学卫星导航定位技术研究中心,武汉430079

出　　处：《导航定位学报》2024年第5期1-8,共8页Journal of Navigation and Positioning

摘　　要：针对基于穿戴式多惯性测量单元(IMU)的行人定位与步态测量应用中,多IMU之间的航向对齐通常依赖磁力计、专业人员辅助以及关节假设模型,操作流程复杂度高且精度无法保障的问题,提出一种适用下肢安装多IMU的航向对齐方法:设计适用足部、小腿和大腿IMU的统一的杆臂补偿零速修正算法,利用行人足部周期性触地规律构造的零速度观测值,准确恢复所有IMU的运动轨迹;然后基于轨迹相似性约束,实现多个IMU的航向对齐;最后在室外开阔场景下评估运动轨迹恢复精度和航向对齐精度。实验结果表明,航向对齐精度和各部位IMU的轨迹恢复精度呈正相关;在行走轨迹长度大于15 m时,各IMU的航向对齐精度均优于1°(均方根值)。该方法操作简单,易于实施,能够满足基于多IMU的人体运动分析和行人定位应用需求。Aiming at the problem that in pedestrian positioning and gait measurement based on multiple wearable inertial measurement units(IMUs),heading alignment usually depends on the utilization of magnetometers,expert intervention and joint hypothesis models,leading to complex operation process and non-guaranteed accuracy,the paper proposed a heading alignment method applicable to multiple IMUs mounted on lower limbs:a unified zero-velocity correction algorithm was designed for IMUs mounted on feet,shanks and thighs,and the law that pedestrians'feet touch the ground periodically was used when walking to construct zero-velocity observations for accurately restoring the motion trajectories of all IMUs;then,based on trajectory similarity,the heading alignment of multiple IMUs was realized;finally,the accuracy of trajectory and heading alignment were evaluated in outdoor open scene.Experimental result showed that alignment accuracy of heading would be positively correlated with trajectory accuracy of IMU in each position,and the average accuracy of heading alignment would be better than 1°(root mean square)when the walking trajectory length is more than 15m;in general,the proposed method would be simple and easy to implement,and could meet the requirements of human motion analysis and pedestrian positioning based on multiple IMUs.

关 键 词：穿戴式惯性传感器 航向对齐 行人航迹推算 人体运动分析 扩展卡尔曼滤波 

分 类 号：TP212.9[自动化与计算机技术—检测技术与自动化装置] P228[自动化与计算机技术—控制科学与工程]