Wireless Sensor Networks At The Traffic Lights Fault Monitoring

The traffic lights are the important tool for traffic management. However, due to environmental or man-made reasons, traffic lights itself occur fault often, which will easily lead to traffic accidents and jams and so on. Therefore, the sooner the fault fixed, the better it will be. There are basically only two ways to report fault:the one is the traffic police found fault on duty daily guard and patrol; the other is enthusiastic citizen to report the failure by the alarm. After received the report, traffic police generally inform the related transport facilities departments via telephone, E-mail, text message ect, Then, they arrange the maintenance worker to repair. Thus, traffic will be impacted much more badly by the weak points of these two ways, which are:on the one hand, there are too many report processes, delayed the time of reaction for fault. If it misconnects in a certain part, it will be delay more; On the other hand, we cannot make sure it is truthful of the information from artificial reaction.With the development of computer technology, sensor technology, networking and wireless communications technologies, and low-power embedded system on a chip technology, it occurred a new wireless sensor networks, which is consisted by a large number of micro sensor node, and to form a distributed sensor and actor intelligent network system by means of radio communication, so as to real-time sense, gather and control information of all monitored targets in the monitoring region.This article research and design the acquisition, transmission, monitoring and display of the fault information on the client by using the wireless sensor network in traffic lights fault monitoring system. Taking advantage of characteristics of wireless sensor networks and computer in that rapid collection, transmission and processing of the information, to be used in fault monitoring of traffic lights, so as to make respond to the fault more quickly and accurately. In this article, firstly make analysis of the reason traffic lights fault caused, find the related techniques and methods of fault detection. Secondly to use51series single chip microcomputer and nRF905wireless transceiver as the core devices to set up a wireless sensor network node, and writing system programs and collection procedures. Then base on the tree and multi-hop topology of network, custom the protocol of physical layer, data link layer and the network layer ect, to build a simple and low-cost wireless sensor networks. Finally, establish a database in the upper computer used to store the data acquired from wireless sensor networks, and written an analog monitoring system in Visual C++based on MapX, use MapInfo format map as the background, so that to display the status of the crossroads traffic lights and wireless sensor network on the monitor screen.