Reseach On RFID Logistics Position Technology

RFID(Radio Frequency Identification) is a wireless communication technology. Through radio frequency signal, the antenna of reader interacts with the antenna of tag which attaches to article. Reader could get data from tag, achieving the purpose that goods are automatically identified. Currently, RFID is widely used in food security, logistics, supply chain, warehouse management and other aspects. Its advantage is particularly suited to be used in indoor position, such as MMS, article sorting. This thesis studies RFID technology and algorithms in indoor position. The thesis tracks and identifies the motive RFID tag. The thesis focuses on the use of RFID indoor position in logistics(article sorting). Combing with RFID indoor warehouse management and monitoring application, the thesis forms RFID logistics positioning system.Firstly, this thesis follows up the background of RFID technology, RFID indoor location technology and current research status. Aiming at several typical RFID indoor localization algorithm and system, the thesis analyses their advantages and disadvantages. Based on current method is interfered strongly with indoor environment and the method does not have enough measurement accuracy, the thesis uses the phase technology according to the existing RFID paper. It proposes PDC(Phase Difference Coordinate System) indoor position method which based on measure tag's phase. The algorithm utilizes different phase method to measure accumulated 80 times tag's phase which arrives to reader's antenna. Then it calculates the initial coordinates of the tag in the area of the candidate. Its position precision is centimeter level. Second it considers when tag in irregular motions. The thesis uses gauss-newton iterative method to estimate the position of tag in every measure time to calculate better trajectory. Finally the thesis applies particle filter to smooth the trajectory. The trajectory is closer to the real tag's trajectory. Though analysis and experiment, the conclusion from precision, anti-interference ability proves the algorithm is better than existing basic indoor location algorithms.Then the thesis studies application though PDC method in indoor logistics. The thesis focuses on solving of the problem of good's automatic sorting on belt in warehouse which utilizes the indoor location technology. The thesis combines with the RFID technology into warehouse management, supply chain management, which is constructed by procurement, distribution, storage, delivery to form the RFID applications in logistics positioning system, making the management in warehouse and goods which flows in the indoor automatic sorting process more efficient. The thesis describes the system including hardware configuration, the build of hardware environment, and the design of software architecture, implementation and functions of the modules, the test of the system. The system displays as a platform of RFID indoor location algorithm, combining with applications of RFID in the warehouse, supply chain and logistics. The result reflects the practical value of indoor logistics location in goods automatic sorting by using RFID location technology. Test result shows that the system achieves good localization accuracy and efficiency.