The Research On Signal Machine Based On Distributed Control Architecture

With the development of economy and the accelerating rhythm of life, more and more people are going to buy private car as their transport and the car ownership has increased rapidly. Because of the relative ly undeveloped traffic facilities and the weak intersection control ability in most cities, the traffic jam has become an increasingly serious phenomenon. In order to adapt to the development trend of urban traffic, and improve the technology level of traffic management and traffic capacity, and improve the mainstream status of more time timing signal machine in most city’s intersection, this paper designs a signal machine system based on the distributed architecture which has the functions of single point control, regional networked control, and self-adaptive control, etc.The design of system hardware platform adopts the organization way of the distributed architecture, and each piece of independent board has a microprocessor, which makes every function board have a certain number of independent control ability. The communication method among the function board is CAN bus, which can make them form a complete system. Among of them, the core control board adopts ARM as its core processor, and it also has the functions of Ethernet communication module, serial communication modular, RS-485 countdown module, 3Gcommunication module, touch screen control module and GPS module, etc. The core control board can communicate with the control center through the RJ45 or 3G module to upload traffic flow information and download control scheme, which can realize the regional networked control by doing this; the core control board can control the count-down board through RS-485 communication; the users can reset the control scheme by the touch screen UI interface; and the core control board can reset the system time based on the data from the GPS module.Light driver board and vehicle information acquisition board use the PIC18F4580 as their core processor. Light driver board can control the lamp working status by the circuit which is composed of optical coupler and silicon controlled rectifier, etc. At the same time, the light diver board can get the running status of lamps by the circuit composed of the current sensor and voltage comparator, etc. The vehicle information acquisition board has the functions of data collection, data analysis and data communication, etc. The vehicle information collected by all kinds of sensors can be transported to the core processor through the circuit of signal acquisition and signal shaping. Then the core processor will analyze those data and judge the traffic conditions.Power supply can provide stable working voltage of 5V and 3.3V for the system. The 220 V alternating current can be converted to 5V output by the voltage transformation module, then the 5V can be converted to 3.3V by LM1117-3.3V. And the main function of backboard is to provide CAN communication channel for every function board in this system.After running and testing, the system can run correctly and complete the control of the cross road. And the research can provide a high reference and practical value for the urban traffic signal control system’s research and development.