Research On Indoor Positioning Algorithm And System Based On Rfid Technology

Building smart cities has become a key measure to solve social development issues,and it can promote innovation in production,life,and management methods.As an integral part of the construction of smart cities,the need for location-based services(LBS)is becoming more and more urgent.Outdoor positioning technology is already very mature as represent by the GPS global positioning system.However,the indoor environment is more complex than ever.Research on indoor positioning methods based on RFID,Wi-Fi,Bluetooth,ultra-broadband and other technologies is in full swing.RFID technology has the advantages of non-line-of-sight,low cost,and high embedding,making it one of the optimal solutions for solving indoor positioning problems.Through the analysis of the existing RFID-based indoor positioning systems and algorithms,we emphatically introduce the RFID positioning system based on Received Signal Strength Indication(RSSI).The LANDMARC algorithm and VIRE algorithm ware studied and introduced in this paper,by summarizing the advantages and disadvantages of the algorithm,the VIRE algorithm is improved from the following two aspects:Aiming at the problem that the linear interpolation error need to be improved when the VIRE algorithm is used to expand the RSSI data set of the reference tag,a method for applying the Kriging interpolation to the RSSI value estimation of the RFID tag is proposed.The algorithm takes into account the correlation between attributes with estimated positions and known reference position attributes,and also deals with the spatial correlation of variables,enabling more accurate estimation of virtual tag data.This makes it more accurate to estimate the virtual tag data.In VIRE algorithm,the threshold parameter in the virtual tag elimination process needs to be obtained through repeated adjustment experiment.The method is complicated.An adaptive threshold adjustment strategy is proposed,by pre-estimating the range of neighboring tags after the virtual tag is eliminated,and the threshold value is gradually adjusted so that the number of neighboring tags is kept in an optimal state and interference is more accurately eliminated.At the end of the paper,an attempt was made to construct an RFID indoor positioning system.Through secondary development of the equipment software,the Experimental system can realize the real-time extraction of experimental data,and initially complete the entire process from data acquisition,storage,data processing,and positioning.Experimental results show that the improved algorithm reduces the cost of the RFID positioning system and improves the positioning accuracy.