Research And Use Of Parking Car Location System Based On UWB

With the rapid growth of urban automobile ownership in China,there is a serious shortage of parking spaces in cities,which leads to frequent traffic congestion,parking difficulties and random parking in parking lots.In order to solve these problems,the traditional parking lot began to introduce intelligent parking management system.The service of intelligent parking management system can make parking and reverse searching more convenient.The efficiency of parking space will be improved if the car owner parks and picks up the car according to the navigation service.However,at present,some intelligent parking management systems can provide online query,booking and payment functions,but rarely can provide precise parking navigation,reverse car search and other functions.The main reason is that the current intelligent parking lot management system lacks a set of accurate,real-time positioning system for the car.Traditional wireless location technologies such as Bluetooth,ZigBee and WiFi,affected by the complex indoor environment,resulting in poor positioning accuracy,it is difficult to meet the requirements for high precision parking car positioning.Therefore,this paper introduces UWB positioning technology for car parking lot positioning,enrich the functions of intelligent parking lot management system.Theoretically,the ranging error of DW1000 chip based on UWB technology is about 10 cm,and the positioning accuracy is relatively high,which fully meets the positioning accuracy requirements of intelligent parking lot management system.The main work and results of this paper are as follows:(1)This paper designs a parking lot car location system based on UWB technology.According to the application environment in the parking lot and the characteristics of DW1000 chip,the layout of base station and electronic tag is discussed.The base station,embedded software program and location algorithm are designed and studied.Finally,the test results show that the positioning system is capable of real-time positioning multiple static and mobile electronic tags.(2)This paper studies a Chan-Taylor collaborative localization algorithm.Simulation for the least square positioning algorithm,Fang algorithm,Chan algorithm and four base station model of Chan algorithm,simulation results show that the four base station model of Chan algorithm positioning accuracy is better.In order to improve the positioning accuracy,the paper also introduces the Taylor series expansion algorithm.The collaborative positioning algorithm uses the initial positioning result of the Chan algorithm as the initial coordinate point of the Taylor algorithm and estimates the coordinate of the tag through multiple iterations.Finally,the simulation results show that the positioning accuracy of Chan-Taylor collaborative positioning algorithm is better than other positioning algorithms.(3)Overall test of the positioning system.The test experiment of indoor parking lot includes ranging test of different distances,single tag positioning test,several tag positioning test and mobile tag positioning test.The test results show that the positioning error of the positioning system is about 30 cm.