| With the development of Chinese national economy, vehicles running on the road have increased year by year, and the network of highway gradually has been established. Since the method of the highway toll collection is almost manual, the process of collection takes long time, and causes the inefficiency. The toll station of highway has been the bottleneck of traffic. Therefore, the use of non-cash payment of tolls and the advanced electronic technology can make the vehicles pass the toll station more quickly. It's the urgent need for the traffic in our country. At the same time, the non-stopping of vehicle passing through the toll station can effectively reduce the mechanical wear and tear, fuel consumption, noise and the resulting large number of issues such as harmful exhaust which are all aroused by the frequent braking vehicle passing through highway toll station. In order to adapt to the development of modern road traffic demand, this paper presents a framework of Electronic Toll Collection of highway which is based on the technology of RFID, and has a research on the related techniques of this system.Firstly, make a survey on the current status of Chinese road toll system, and have an analysis of the shortcomings of the charging method based on manual. Then have a study of the system which is used the Electronic Toll Collection, and design the framework of this system. Through the analysis of the functionality, composition, application of the system, present the key techniques of ETC.Secondly, introduce the principle of Radio Frequency Identification (RFID) technology, the typical structure of RFID system and other basic working principle of knowledge. Then focus on the design of the RF system hardware and software based on the RF chip of nRF401. In this system, choose W77E58 which has the double serial port as the MCU of the Reader module, using its serial port connecting to the main control PC and nRF401 module. Choose AT89S52 which is cost-effective and low-power as the controller of Tag module, and communicate with the wireless module through the serial port.Then analysis the software flowchart of the PC module, Reader module and Tag module.Thirdly, in order to solve the data conflicts in RF system, arise the research of the anti-collision of RFID system. At present, the anti-collision algorithms are almost based on the binary anti-collision algorithm and slot ALOHA anti-collision algorithm. Through the analysis of the anti-collision algorithm based on the binary, propose an improved anti-collision algorithm—Group of binary search algorithm. And then simulate this algorithm in Matlab, and prove that this algorithm which is proposed in this paper is more efficient than the present binary algorithm. Through the analysis of the anti-collision algorithm based on the slot ALOHA, propose an improved anti-collision algorithm—based on frame-slotted ALOHA algorithm. By limiting the tags of responding, reduce probability of conflict, and improve the efficiency of the identification for tags. Simulate this algorithm in Matlab, and gain the performance curves between this improved algorithm and ordinary algorithm. It is proved that the proposed algorithm by this paper is more efficient than the typical ALOHA method.Then, in the practical application of the toll collection, in order to prevent vehicle owners cheating by changing the vehicle tag, study the identification technique of the vehicle model. Based on constructing membership functions of fuzzy theory, propose a method of pattern recognition on vehicle by extracting characteristic data. The method can recognize normal car, jeep, truck and bus etc.Finally, conclude the main work of this paper, and then make a prospect and plan for the further studies.
|
PDF Full Text Request