Design Of High Precision Indoor Positioning System Based On Ultra-wideband

Nowadays,with the rapid development of science and technology,the Internet and smart phones have been popularized in our life,and the communication service based on location information has gradually attracted extensive attention and attention from all walks of life.The world's four major satellite positioning systems basically occupy the outdoor location information services,but can not be effectively applied to the indoor environment.Therefore,a kind of indoor positioning technology with strong communication signal,high precision and low cost is needed.Now has all kinds of indoor positioning systems commonly used technology UWB,ZigBee,Wifi,bluetooth,etc.,is one of the most popular the most pertinent is only ultra-wideband UWB technology in recent years,but it is a kind of not using carrier using pulse signal wireless transmission of emerging technology and has strong penetrating power,low power consumption,good anti-multipath effect,high accuracy,etc.The favored by researchers,has the very broad prospects for development.For the indoor positioning system based on UWB technology,the main research contents and achievements of this paper are as follows:(1)According to the characteristics and contents of Chan and Taylor algorithms,an improved algorithm based on weighted least squares is proposed by combining the weighted residual correction of Chan algorithm and the iterative thought of Taylor algorithm based on threshold value.First,the nonlinear equations are established according to the TDOA measurement data,and the initial estimated coordinates of the label are obtained by weighted least square method(WLS).Then the system of coordinate error equations is constructed,and the error value is calculated by WLS to determine whether the error is less than the threshold value.If it is less than the threshold value,the current result is taken as the label coordinate.Otherwise,the estimated coordinates and the error value are used as the new estimated coordinates to construct the coordinate error equations and carry out WLS estimation until the error is less than the threshold value,and the results are obtained.(2)This paper also deduces the extended Kalman filtering algorithm(EKF)and analyzes the error source.By resolving and correcting the measured outliers,the influence of outliers on the filtering effect can be effectively reduced.The improved EKF was used to filter the positioning results obtained by the algorithm.Matlab simulation shows that thejoint positioning algorithm has better positioning accuracy and stability than the single algorithm.(3)at the end of this paper,the overall framework of the positioning system is constructed.DWM1000 module is used to design the hardware circuit of the label and the base station,as well as the embedded program and the upper computer software,and the positioning system as a whole is tested.The test results show that the positioning accuracy of the system reaches about 15 cm,which proves that the UWB indoor positioning system can be applied in practice and has certain feasibility.Figure [35] table [11] reference [62]...