Design Of Indoor Positioning System Based On TDC-GP22

Indoor positioning technology has a very high practical value,and it is a promising research topic.The existing indoor positioning technology not only has the problem of the balance between the program location costs,location accuracy and the universal nature,but the positioning accuracy and reliability of their own are also difficult to satisfactory.Improve the existing positioning technology at the same time,exploring new positioning program is also a new path of our study.Aiming at indoor location problem,this paper presents a TDOA(Time Difference of Arrival)indoor positioning system design scheme without clock synchronization.This system uses TDC-GP22,a high-precision time-to-digital converter,to measure the propagation delay difference(TDOA)of the signal from the radio transmitter of the robot to the auxiliary node with the aid of radio communication circuit,using the hyperbola Position method to estimate the target relative coordinate position.In this paper,the background and current situation of indoor positioning technology are briefly introduced.The advantages and disadvantages of the existing indoor positioning technology and positioning algorithm are compared.At the same time,the research process of time measurement method and method is expounded.Both of the measurement methods and measurement accuracy are sufficient to apply the field of indoor positioning.Secondly,the design scheme of indoor location system based on TDC-GP22 is proposed,which is mainly introduced from two aspects,the overall hardware layout and software system design.Hardware from the chip selection and circuit design reasons,etc.;software on the bottom of the main module of the drive and the upper application design to illustrate.The working mode and software driving design of time-to-digital converter TDC-GP22 are mainly introduced.Then,the algorithm of TDOA time difference method is discussed.The combination of the algorithm of Chan algorithm and Taylor expansion method is used to solve the localization problem.Firstly,the initial target position is estimated by Chan algorithm.Then the initial solution is obtained by Taylor Expansion method for iterative calculation,in order to obtain more accurate positioning coordinates.At last,the system is tested by LOS experiment,and the algorithm is calculated by Chan algorithm,Taylor expansion method and the combination of the two algorithms respectively.The results show that the TDC-GP22-based indoor positioning system can achieve an error of less than lm when the positioning result is ideal under the combination of Chan algorithm and Taylor expansion method.