Traffic Signal Control Device Based On Open Bus Protocol

With the rapid economic development, transportation has been an important support. A large demand for the transportation has been proposed. The traditional means of traffic controlling has been unable to keep up with the pace of progress of modern society. Development of Intelligent Transportation System is imperative. Traffic signal controller is the end of Intelligent Transportation System, the realization of the concept of traffic control and important part of the Intelligent Transportation System. Traditional traffic signal controller drives the traffic lights with the single cable for every light. Too high costs for spending too much cable while the intersection needs large scale of traffic lights.In order to realize the regional signal control, the function of networking is inevitable. However, most developer focused on the subject of core network or traffic signal controller itself and always ignore the end of ITS—controlling of traffic light. The key point of research of this subject is to break through one of the difficulties of modem traffic signal controller. In order to realize communication controlling of the traffic lights, the common traffic lights must be made of a smart node.The design includes the hardware interface of the host for traffic controller, software platform, application procedure and communication protocol between host and smart node. In addition, the designing of hardware and software for smart node must be required. The communication in traffic controller and traffic lights is the wireless channel. The physical interface is a wireless data transmission module, and there is a wireless communication protocol running. Communication protocol for application layer can be designed by individual. Smart traffic light module contains the core board of smart node and the LED driver. The CPU for smart node is the microcontroller (STC series), and serial port is RS-232C for local debugging. This structure eliminates all cables from the traffic lights to traffic controller, greatly reduces the costs of equipment, materials and maintenance, improve the environment redundancy of the traffic signal, and the efficiency of construction.