基于足绑式INS的行人导航三轴磁强计在线校准  

Online three-axis magnetometer calibration for a pedestrian navigation system using a foot-mounted inertial navigation system

作　　者：张新喜[1,2] 张嵘[1] 郭美凤[1] 程高峰[2] 牛树来[2] 

机构地区：[1]清华大学精密仪器系,北京100084 [2]装甲兵工程学院控制工程系,北京100072

出　　处：《清华大学学报（自然科学版）》2016年第2期211-217,共7页Journal of Tsinghua University(Science and Technology)

基　　金：中国第二代卫星导航系统重大专项(GFZX0301010516);总装惯性技术预先研究项目(51309010301)

摘　　要：基于低成本微电子机械系统(MEMS)惯性传感器的足绑式惯性导航系统(INS)是行人自主导航常用的一种方式,足绑式INS可与磁强计组合来约束航向角误差,但磁强计存在误差需要校准。该文提出了适合行人导航的磁强计误差模型和在线校准算法。根据磁强计的误差特性和足绑式INS的机动性,建立了磁强计误差变量的状态方程和观测方程,利用扩展Kalman滤波器(EKF)对三轴磁强计误差进行在线估计和实时校准,利用零速修正(ZUPT)算法和磁航向角约束算法对足绑式INS的误差进行约束。为验证算法的有效性,在操场进行了一圈徒步行走实验。实验结果表明:使用磁强计误差在线辨识和校准算法后,与未进行磁强计误差校准相比,行人导航东向终点误差由-110.7m减小到1.8m,北向终点误差由37.8m减小到5.2m,磁强计误差得到有效校正。该算法实现了基于足绑式INS的行人导航磁强计误差在线校准,大幅提高了行人自主导航的定位精度。Foot-mounted inertial navigation systems（INS）having inexpensive micro electro mechanical system（MEMS）-based inertial sensors are widely used for pedestrian navigation.A foot-mounted INS can be combined with a magnetometer to constrain the heading angle error,but the magnetometer needs to be calibrated before use.This paper presents a magnetometer error model and an online calibration algorithm based on the foot-mounted INS characteristics.The magnetometer error characteristics and the foot-mounted INS mobility characteristics are used to develop a state equation and a magnetometer error measurement equation.An extended Kalman filter（EKF）is used for the online estimation and real-time calibration of the three-axis magnetometer errors with the zero velocity update（ZUPT）algorithm and a magnetic heading angle constraint algorithm for error constraint.The algorithm is validated by walking in a square playing ground.The results show that the online estimation and calibration algorithm reduce the end position error of the east direction from-110.7to 1.8mand the end position error of the north direction from 37.8to 5.2m compared to the system without calibration. This algorithm provides online calibration of magnetometer errors and significantly improves the positioning accuracy of pedestrian navigation.

关 键 词：行人导航 足绑式惯性导航系统(INS) 零速修正(ZUPT) 扩展Kalman滤波器(EKF) 磁强计校准 

分 类 号：U666.1[交通运输工程—船舶及航道工程]