Design And Implementation Of Indoor High Precision Positioning System Based On UWB

In many indoor occasions,the positioning system needs to locate existing items and staff in order to play a role in system management and monitoring.Compared with WIFI,Bluetooth,RF,ZigBee,ultrasonic,UWB technology has good anti-multipath capability,anti-interference ability and high positioning accuracy,so it has great advantages in indoor positioning.According to this requirement,this project designs and implements a UWB-based indoor high-precision positioning system.The base station and the tag obtain the distance between the tag and each base station through UWB communication.And the PC receives the positioning information sent by the primary base station.After positioning algorithm solves the information,the PC displays real-time position and trajectory.The base station and the tag terminal and embedded software is designed on UWB communication module.The DWM1000 designed by DecaWave is selected as the UWB communication module.The base station and the tag record the timestamp of receiving or transmitting the UWB signal each time.The UWB communication software is designed based on the symmetrical double-sided two way ranging algorithm,and the STM32 calculates the time difference between the arrival of the tags and the base stations.After that,the primary base station sends the original measurement data to the PC through the WIFI module for further calculation.The Partial Least-square method is used to estimate the time difference of the arrival time of the tag obtained by the hardware measurement,and the initial value is used as the input end of the particle swarm algorithm to obtain the tag coordinate value.Combined with the unscented Kalman filter algorithm for tracking prediction,the search range of the particle swarm algorithm is set with the predicted value as the center,which accelerates the convergence of the particle swarm algorithm,improves the running speed of the algorithm,obtains a smooth motion trajectory,and improves the system positioning effect..The system positioning effect was tested as a whole.Based on Python,the PC-side monitoring software was designed to display the label position and draw the motion track in real time.The host computer also has functions such as network connection,user management,data storage and historical data query.The test results show that the system positioning error is up to 7cm in the line-of-sight environment for the stationary tag;in the non-line-of-sight environment,the real-time motion trajectory displayed by the host computer is consistent with the actual motion trend.Therefore,the test results show that the system realizes high-precision positioning of indoor tags and has certain adaptability to non-line-of-sight environment,and can monitor the position and motion state of tags in real time on the PC side.