Research Of Key Technology Based On RFID In Modern Logistics

The Radio Frequency Identification (RFID)is a new generation non-touching automatic identification technology for supporting an automatic tracking and identification of an item in the Ubiquitous computing environment. RFID system is composed of readers and tags, transmitting data through a radio frequency. As a promising technology, the RFID has been wide applied in social, economic, national defense and many other fields over the past years.The thesis focuses on RFID technology applied in logistics since the traditional bar code has not been fit for the development in logistics. For the modernization of logistics, the thesis proposes that UHF RFID should replace bar code in modern logistics. Compared with previous research, this thesis for the first time studies the solution of collision problem in RFID system and the advance of target location in logistics system, and it also presents solutions to modern logistics based on RFID. The main contents of thesis include the following:First, the thesis researches the application and development of RFID both at home and abroad and then the analysis is made concerning logistics industry's mode, characteristics, development and status quo as well as the restricting factors in our nation's logistics industry. The analysis comes at the conclusion that the traditional bar code has been unable to meet the modern needs of the logistic supply chain and therefore, the application of EPC code technology in logistic industry for the replacement of code bar which can complete object labeling and data collecting can greatly improve the efficiency of logistic supply chain.Second, the thesis focuses on the anti-collision algorithm in the RFID System. Aiming at the anti-collision problem in communicating between readers and tags, an improving dynamic frame slot ALOHA algorithm is designed. Under the circumstances of many tags taking part in identification, the algorithm estimates existing the number of tags and groups, then each group transfers dynamic frame slot ALOHA algorithm respectively, estimates the number of collision slots in each group and adjusts the number of slots in a frame. Thus the efficiency of the system is raised and the stability of the system is strengthened. Other side, the elementary binary search algorithm was analyzed, and an adaptive anti -collision algorithm based on grouping was proposed. In this algorithm, reader estimated the amount of electronic labels firstly,using math measure to work the best gene out and identify labels groups by groups. Besides, it models and imitates with MATLAB according to this project, and compares and analyzes the result of imitating, verifies the accuracy and possibility of the model. Through the features compared, we can find the proposed algorithm is more effective than others introduced.Third, access to a number of related papers in the literature, the thesis summarize the status of target location on the wireless sensor networks, and study the sensor network nodes, the location strategy and the process of target location. Then, we research a multilateral algorithm for target location, the algorithm uses a least-squares algorithm and a weighted least squares algorithm. Through simulation, multilateral algorithm has a higher accuracy than other algorithms.Finally, it sums up and analyzes the research contents and the shortage of this thesis, puts forward an outlook for further research.