Vehicle Detection And Identification System Research Based On Piezoelectricity Transducer

Research of on-road vehicle detection and identification system is the key to the construction of traffic intelligence. With the development of transducer and microelectronics techniques, vehicle detection and identification system which once relied on magnetic circuit is about to employ a series of new technology like microwave, infrared, PVDF, video, and radio frequency. The new vehicle detection and identification system combined PVDF vehicle detector and radio frequency device, relatively more durable and easy to fix with little damage to the road, would be prospective to be applied in the field of developing traffic intelligence.In the field of traffic intelligence, after a survey to the demand for vehicle detection and identification system and its current researches all over the world, the thesis is going to explore a vehicle detection and identification system based on piezoelectric transducer technology. To fulfill the goal, great efforts have been devoted to the design of separated modules, integration of the whole system, and eventually successful validation of the system. During the experiment, non-stop weighing with a speed of 5 km/h-200km/h, vehicles'radio frequency message switching within 10 centimeters and the confirmation of vehicles'speed, tread and wheelbase have been accomplished. The main researches are as follows:1. Under the precondition of a board reference to literatures, the thesis analyzed the current researches and future trends of vehicle detection and identification system, moreover compared different kinds of vehicle detectors and identification device and therefore ensure the programme of employing PVDF detector in the vehicle detection and identification system.2. In order to meet the demand of non-stop weighing and on-road running vehicle, the experiment adopted the PVDF axes vehicle detector made by MSI Corporation. The result of the experiment suggested a design programme in which two axes should keep parallel, while one axis should be tilted.3.For the demand of vehicle detection, a research was made to explore the signal input amplifying circuit, modulus change-over circuit, data communication circuit on AT89C51 singlechip, ADC0809 8 bits A/D converting module and MAX232 level converting CMOS chip.4.In the research of vehicle detection and identification system, the thesis started up the radio frequency identification system to make RF500 CMOS chip read-writer and contactless IC card fixed on vehicle to undergo radio communication at one time while both vehicle are within 10 centimeters and to catch data of vehicle about its type and consumer. Such design programme achieved precise identification of vehicle's consumer and type with low cost.5. A serried of experiments, e.g. non-stop weighing, have been carried out.