Indoor Ranging And Positioning System Based On UWB

In recent years,new requirements related to geofencing,mobile payment,and big data processing have expanded the application scenarios of location services.At present,GPS and Beidou technology can better meet the demand of outdoor location service,but there is still a lack of mature technology to meet the real-time accurate location service in the indoor environment,such as the positioning of personnel in hospitals,tunnels,substations and advance warning of dangerous areas.Compared with the traditional wireless technology,UWB(ultra wide band)has many advantages such as strong penetration,low power consumption,strong anti-noise ability,and good time resolution.It is very suitable for the design of indoor positioning system.Therefore,the research and implementation of indoor positioning technology based on UWB has a very high engineering application value.Based on the actual demand of indoor positioning service,this paper designs and implements an indoor 3D positioning system based on UWB.The specific research contents are as follows:(1)The traditional bilateral bidirectional ranging algorithm is improved and optimized,theoretically reducing the communication times of the tag 3/4,and saving the energy consumption of the tag system by about 40%.(2)Aiming at the ranging error caused by indoor non-line-of-sight environment,a distance correction method based on distance residuals was proposed.This solution is based on the distance residual as a judgment factor,and selectively uses Kalman filtering to correct part of the ranging error,which improves the ranging accuracy of about 8 cm,thereby improving the positioning accuracy.(3)Designed a complete base station and tag hardware circuit based on the UWB communication chip DWM1000 to provide hardware support for the ranging and positioning software system.At the same time designed and developed the embedded software of the lower computer and the software of the upper computer: designed the two sets of data frame transmission protocols are used to communicate between with tags and base station,UDP communication between the base station and the host computer.A timer-based terminal timing scheme is designed.(4)Tested and analyzed the ranging and positioning system designed in this paper to verify the reliability of the system.The experimental test results at the engineering site show that the ranging error of the distance measurement and positioning system designed in this paper is not more than 10 cm and the positioning error is not more than 20 cm.At the same time,the performance of the signal in the non-line-of-sight propagation is stable.It can meet the needs of indoor positioning systems in most scenarios.