Development Of Automobile Blockader Control System

ITS , Intelligent Transportation System, has come into being in the recent years as the technology of electronic information has been applied in rapidly-developing transportation. It synthesized the technologies of advanced information processing, communication, electronic control and computer processing, etc. The real-time, nicety and high-speed system of transportation has been set up accordingly. With a view to the basic and the most important part of ITS, this paper researched on detecting information of vehicles in expressway for ITS. We have discussed the principle of detecting information of vehicles and the implementation, and, designed a supervisory control and data acquisition system for traffic information based on the principle of electromagnetic induction.This paper introduces how to realize traffic information collector by single chip microcomputer, presents some chief interface circuit, and gives some methods of traffic information collecting and data processing. The structure and realization method of a kind of moving vehicle detector are introduced by this paper. The moving vehicle detector, which is based on inductive circular loop, detects the information of vehicles according to the inductive signal and send the information to the main controlling computer.The output signal was connected to the input port of CCP (Capture/Compare/Pulse Width Modulation) in the PIC16F877. Then the MCU PIC16F877 can acquire the oscillation frequency. The inductance coil will vary when motor vehicles passing over the winding. Then the oscillator frequency will be changed. The passing vehicles can be detected by the change of oscillation frequency. Based on these, this paper gives a detailed description of the software and hardware design and implementation of a key equipment of the system, the car sensor, including the structure and operating principles of hardware and the software algorithm . Then it discusses the operating principles and the design scheme of the whole system and transmit the corresponding data to the upper computer in toll station control center through RS - 485 serial port of the toll computer. And according to the statistic date, we can calculate the traffic flow parameters of velocity , length , runoff, density, occupancy rate of traffic road and so on.This system has not only overcome the shortcoming of dependency , but also researched for developing the high property Intelligent equipment in theory and practice.