Research On Indoor Positioning Based On RFID

With the increasingly rapid development and progress of intelligent technology,RFID technology is widely used in many areas like the production process,the warehouse supplies and the unmanned supermarket since it is characteristics of non-line of sight,short delay,low cost,etc.However,traditional RFID tags have some disadvantages in special metal environments,such as large size,anti-metal poor performance.And the traditional RFID location technology has high costs due to array antennas.So RFID tags and RFID location technology has been a research focus.In this paper,a passive RFID tag antenna is presented to be used for scalpels.And a low-cost solution of indoor two-dimensional location with a reader and a passive RFID tag array is also proposed.This work provides a reference method for other medical instruments management and RFID indoor locating technology.The main work is as follows.Firstly,an anti-metal passive RFID tag antenna is designed for scalpels.The tag antenna achieves miniaturization by using a short-circuit technology and a high dielectric constant loading technology.The tag antenna size is 66×5×0.8mm~3.The tag antenna is embedded in the scalpel handle,which realizes the integration of the tag antenna and the scalpel,and the read range is 1m.The antenna is processed according to the simulation optimization result,and the test result shows the antenna can be applied to the scalpel.The RFID passive tag antenna solves the problem of scalpel management in this paper.Secondly,the direction of arrival based on the MUSIC algorithm is estimated,and the AOA triangle algorithm is realized the indoor two-dimensional location.In this paper,indoor 2D attitude estimation uses 3-element equidistant linear array based on MUSIC algorithm and AOA triangle algorithm.The experimental results show that the minimum error of indoor 2D location is 0.37m,and the average error is 0.49m.Compared with the traditional location method that uses a reader array antenna,using a single reader and a tag antenna array not only can realize locating but also can reduce system cost.In short,this passive RFID tag antenna can be applied to the track management of the scalpel.And the design can be referred to other medical instruments.So it has a great application value.Using a single reader and a tag antenna array can reduce the hardware cost of the locating system and provide a new idea for location system construction.