基于SR-EKF的UWB/IMU组合室内定位系统

UWB/IMU Combined Indoor Positioning System Based on SR-EKF

UWB定位技术定位精度高、系统结构搭建简单,但在遮挡物影响下性能降低.IMU计算目标位置不受周围环境干扰,长时间工作会存在误差累积.本文提出一种基于平方根扩展卡尔曼滤波法(Square Root-Extended Kalman Filter,SR-EKF)的惯性测量单元(Inertial Measurement Unit,IMU)/超宽带(Ultra-Wideband,UWB)组合室内定位技术.平方根扩展卡尔曼滤波融合IMU/UWB测量数据,通过提高描述状态量的协方差矩阵精确度,进而对状态量校正.同时能够补偿IMU误差累积,降低加速度计和陀螺仪零偏,克服复杂环境下未知影响,提高定位精度.实验结果显示,定位算法能够有效反馈IMU进行误差补偿,并缩小算法估计位置与真实位置之间的误差值,实现高精度目标定位.

UWB positioning technology has high positioning accuracy and simple system structure construction,but its performance is reduced under the influence of obstructions.The IMU calculates the target position without interference from the surrounding environment,and errors will accumulate when working for a long time.An inertial measurement unit(IMU)/Ultra Wideband(UWB)integrated indoor positioning technology based on square root extended Kalman Filter(SR-EKF)is proposed.The square root extended Kalman filter fuses the IMU/UWB measurement data,and then corrects the state quantity by improving the accuracy of the covariance matrix describing the state quantity.At the same time,it can compensate for the accumulation of IMU errors,reduce the zero bias of the accelerometer and gyroscope,overcome unknown influences in complex environments,and improve positioning accuracy.With the help of MATLAB platform simulation experiments,the simulation results show that this positioning algorithm can effectively feedback the IMU for error compensation,and reduce the error value between the algorithm estimated position and the real position,and realize high-precision target positioning.