Research On Algorithm Of 3D Localization Based On RFID Middleware

Accurate and efficient RFID tag localization is significant to a large number of existing and upcoming RFID applications. RFID system with its fast scanning, small size, reusable, high-capacity, high security, anti-interference ability and other advantages has been widely used in logistics tracking, aspects of warehouse management, personnel management and automatic operation. Existing localization technologies including GPS, Wi-Fi, Bluetooth, Zig Bee, RFID, RFID UWB, each technology has its advantages and disadvantages. Comprehensive measure of cost, accuracy, range, power consumption in four areas, RFID indoor localization to become a preferred solution.RFID localization algorithm based on different scenarios using different classification methods. The locate target can be divided into: active and passive localization; The method of locating can be divided into: Localization measured in the direction(Angle of Arrival, AOA) based on the locating signal strength(Received Signal Strength Indicator, RSSI);based locating arrival information(Time Of Arrival, TOA and Time Difference Of Arrival); and according to the spatial dimension can be divided into: a two-dimensional spatial localization, three-dimensional localization. Currently two-dimensional localization algorithm has been a lot of research, three-dimensional space localization due to the complexity of the environment, multidimensional space, noise, interference and other factors, the three-dimensional spatial localization in improving the locating accuracy, cost savings locate a greater challenges. This article describes the existing RFID-dimensional and three-dimensional spatial localization algorithm, summarizes the advantages and disadvantages of the algorithm, proposed a three-dimensional passive tag location algorithm and a three-dimensional space of active tag location algorithm, Simulation and comparison algorithms verified the accuracy of the location algorithm; expand existing RFID middleware location middleware design and implementation. The main work of this paper includes:(1) Analyze the state of RFID three-dimensional location algorithms, Summarize the advantages and disadvantages of three-dimensional location algorithms. Analysis existing RFID middleware and RFID locating engine architecture lay a foundation for RFID location middleware architecture design.(2) Proposes an improved Nelder-Mead minimizing error function target location and APM target location three-dimensional passive tag location algorithm. Algorithm by dividing the signal strength level, estimate the distance between reader and target tag, estimated target position by three balls intersection formula. Finally, using the least squares method to reduce the target estimation error. Contrast algorithm simulation data shows that algorithm uses eight readers and Nelder-Mead minimization algorithm uses 64 readers get close location errors. At the same time our algorithm error range is 0.2-0.7m, APM algorithm error range is 0.2-1.8m, and our algorithm has higher accuracy and error stability.(3) Proposes an improved Nelder-Mead FBM Three-dimensional active tag location algorithm. Algorithm by estimate cross section center and radius under signal ball, using a mathematical model calculate the target reader coordinates. Contrast algorithm simulation data show our algorithm error range is 0.4-0.62 m however Nelder-Mead FBM algorithm error range is 0.55-0.7m, our algorithm has higher accuracy and stability boundary error.(4) Study extends RFID middleware’s location middleware architecture design and implementation. Extended localization process RFID middleware layer includes a data fusion module, positioning module, Web View module three major functional modules. And RFID middleware integration three-dimensional positioning algorithms active tags and passive tags localization algorithms.(5) Improved algorithm data test and Performance test for RFID location middleware architecture design and implementation.This paper provides a useful reference for three-dimensional RFID indoor localization Research and Design.