Research On Road Vehicle Positioning Algorithm Based On UWB Technology

The project of intelligent,green and safe transportation construction is proposesd in the 14 th Five-Year Comprehensive Transportation Development Plan of Inner Mongolia Autonomous Region,which to promote the building of advanced intelligence,low-carbon environmental protection,safe and reliable comprehensive transportation system.One of the important links is the construction and improvement of the highway traffic operation and supervision service system.Based on the plan,a science and technology project of Inner Mongolia Autonomous Region was approved about expressway intelligent road perception and ETC fusion monitoring system.The system includes functions of vehicles operation status real-time monitoring,road section capacity analysis,vehicles statistics and moving history track reproduction.The thesis mainly studies the positioning algorithm of moving targets,which is based on the positioning accuracy and system capacity.This thesis mainly focuses on the positioning algorithm study based on UWB technology to realize the goal of road moving vehicle positioning and lane positioning.The main research work has been done as follows:(1)The TOF ranging algorithm is studied,and the theoretical derivation of the ranging error of the TWR algorithm is analyzed by establishing the error model.On the basis of the error model,the ranging error of the TWR algorithm in three different cases is verified by numerical simulations,and the advantages and disadvantages of different TWR algorithms are analyzed and compared.The theoretical analysis results and the simulation results show that the ranging error can be effectively reduced by using the ALTDS-TWR algorithm in general.(2)The TDOA and TOF joint positioning algorithm is studied and optimized,and the TDOA and TOF joint positioning algorithm is improved based on the requirements of high accuracy,high refresh rate and high system capacity for road vehicle positioning.The project focuses on solving the problems of unstable positioning accuracy of the single TDOA algorithm and the large UWB communication volume caused by the need for multiple TOF ranging during positioning of the traditional TOA algorithm,which effectively improves the system capacity while ensuring the system positioning accuracy.In time synchronization,the joint algorithm adopts the method without continuous synchronization,which is suitable for the high real-time positioning environment such as road vehicle positioning.The temporal performance analysis results and simulation results show that the improved TDOA and TOF joint algorithm improves the stability of positioning accuracy and saves system capacity compared to the traditional single positioning algorithm.(3)The software design of the positioning module in the positioning system was completed.Real vehicle tests were conducted in highway scenarios,and the positioning data obtained from the tests were analyzed,indicating that the positioning system based on the TDOA and TOF joint algorithm can basically meet the project requirements.This joint algorithm can provide positioning algorithm support for the implementation of the highway intelligent road sensing and ETC fusion monitoring system.