Design Of Indoor Positioning System Based On Ultra Wideband Technology

The management and monitoring of indoor dangerous equipment and valuables through precise positioning technology is of great significance to the protection of property and personal safety.At present,indoor positioning technologies include WIFI,ZigBee,Ultra WideBand(UWB),etc.Among them,UWB technology has the advantages of good anti-multipath,anti-interference ability and high positioning accuracy,which makes it have greater advantages in the field of indoor positioning.Therefore,this subject developed a high-precision indoor positioning system based on UWB technology.Firstly,the traditional TDOA positioning algorithms such as Fang,Chan and Taylor are compared and studied.After simulating and analyzing its positioning performance,the Taylor algorithm with the highest positioning accuracy is selected as the research object of this paper.In order to solve the problem that the label is in the three-dimensional space but only needs its two-dimensional information in the actual positioning application,the three-dimensional Taylor algorithm has high positioning accuracy and poor real-time performance,while the 2-dimensional Taylor algorithm has good real-time positioning accuracy and poor accuracy.This paper improves the 2-dimensional Taylor algorithm based on the label height.A mathematical model is established and the algorithm is simulated.The simulation results show that the improved Taylor algorithm has better positioning real-time performance than the 3-dimensional Taylor algorithm and higher positioning accuracy than the 2-dimensional Taylor algorithm.It can meet the practical requirements for positioning accuracy and real-time performance.Then the overall scheme of the system is designed.The hardware of the system includes base stations and tags,and the upper computer software of the system includes background and front-end interface.The base station and the tag adopt an integrated design,which is composed of the STM32 main control chip,the DWM1000 ultra-wideband communication circuit,the dial switch circuit and the power circuit,and is distinguished by the dial switch.The background completes functions such as data analysis,location calculation and database management.The front-end interface completes human-computer interaction functions such as location monitoring,alarm statistics,and device management.Finally,a test platform was built in the indoor environment to verify the system performance and accuracy.In order to verify the system performance,the real-time positioning and electronic fence alarm functions were tested.The test results show that the entire system meets the functional requirements of real-time display of positioning coordinates and alarms.In order to verify the accuracy of the system,In order to verify the accuracy of the system,the positioning errors of the real coordinates and measured coordinates of different tag heights of grid points were calculated,and the positioning deviation of the label along the straight line and the positioning deviation of the calibration trajectory are compared,and it is concluded that the system can meet the requirements of 30cm positioning accuracy and can be practically applied.