UWB Localization Based On Improved TWR And TDOA Positioning Algorithm

With the popularity of intelligent devices and the development of wireless communication technology,the demand for indoor wireless location with high accuracy is also increasing.Indoor location information services can be used in many scenarios,such as factory personnel supervision,public safety emergency response,positioning navigation and dating interaction.At present,the outdoor location and the related location based services have matured.The GPS satellite positioning system and the Beidou satellite positioning system have been widely used,and have been widely recognized by the users.In the field of indoor positioning,due to the cost,positioning accuracy,complexity and other factors,there has not been a perfect solution.It also needs further attention and development.The common indoor positioning techniques include infrared,WiFi,Bluetooth,ZigBee,ultrasonic,RFID and so on.These technologies have not been widely used because of the constraints of various factors.Ultra Wide Band(UWB)is a new wireless communication technology with broad prospects.UWB signal has high time resolution and large bandwidth,and can achieve high speed data transmission in short distance,and it has strong ability to resist multipath fading.Therefore,UWB technology has received great attention in high-precision ranging and positioning in recent years.Aiming at the poor positioning accuracy or poor anti-multipath performance of traditional wireless positioning technology indoors,an indoor positioning system based on UWB technology was designed and implemented by this paper.Firstly,a system structure of real-time interaction between location server and mobile terminal application was put forward,which solved the problem of indoor mobile personnel's autonomous location and navigation.Secondly,aiming at the multi label channel conflict problem,an effective multi label scheduling mechanism was proposed,which enabled the system to locate multiple targets at the same time.Then,a radio message was added to the Two-way Ranging(TWR)algorithm to reduce the ranging error caused by clock drift,so as to improve the performance of the algorithm.Finally,the hyperboloid equation set achieved by Time Difference Of Arrival(TDOA)positioning algorithm was linearized and then solved by Jacobi iteration method,which avoids the cases that the use of standard TDOA localization algorithm is difficult to solve.After testing,the system can work stably in rooms,corridors and other scenes,and the location error is within 30 centimeters.Compared with the positioning system based on WiFi and Bluetooth,the positioning accuracy of the system is improved by about 10 times,and it can meet the requirements of precise mobile location in complex indoor environment.