Research On Indoor Location Method Of Mobile Robot Based On RFID

In the field of intelligent warehouse and intelligent logistics,the application of mobile robots is more and more extensive,greatly improving the work efficiency.In indoor environment,the positioning technology is the core foundation of mobile robot movement operation.At present,indoor positioning technology has a lot of development,put forward a variety of solutions.Among them,Radio Frequency Identification(RFID)technology,with its prominent advantages of ID Identification,non-line-of-sight and low cost,has gradually attracted the attention of researchers,and has great research potential and application value.In this paper,mobile robot and RFID positioning technology are combined.On the premise of ensuring low cost,easy operation and good real-time performance,this paper proposes a mobile robot positioning method based on RFID tag combination,and preprocesses the calibration and phase information of mobile robot-antenna system before positioning to form a set of positioning solutions.The specific research contents are as follows:In the RFID positioning scheme,when the reader antenna is mounted on the mobile robot,the relative position relationship between the two is not clear,and manual calibration will affect the positioning accuracy.This paper proposes an RFID antenna position calibration method based on phase measurement.By using the antenna position calibration model,the position parameters of the RFID antenna relative to the mobile robot are calculated,which can lay a foundation for the subsequent positioning of the mobile robot and reduce the errors caused by the relative position of the manual measurement system.The correctness and effectiveness of the method are verified by simulation and experiment respectively.Based on the prediction principle of phase change,a method of unwinding filter based on Kalman filter principle is proposed.In the noisy environment,the effect of phase preprocessing on noise reduction filtering is obvious,and the experimental results show that the positioning accuracy can be improved by about 30%.The influence of multipath effect on the phase of indoor environment in the positioning process is studied,and the influence mechanism is analyzed.Then,a phase difference-pose positioning model based on RFID tag array and mobile robot is established.Based on the theory of optimization solution,the solution of this model is transformed into a nonlinear least square problem.Finally,the mobile robot is positioned by iterative optimization method.By analyzing the simulation results,it is found that the positioning model has better anti-jamming ability when more data points are used to solve the positioning.Combined with the RFID system and the hardware and software platform of the xianfeng 3 robot system,the upper computer program was written,and the mobile robot circular trajectory positioning experiment was completed,which verified the correctness and rationality of the positioning model proposed in this paper.The average positioning error was about 5cm,with a good positioning accuracy.