Research And Implementation Of Embedded Loop Vehicle Detector Based On STM32

Intelligent transportation system is the development direction of the future transport system, Many advanced technologies are used for transportation management, aimed to build a kind of effective and realtime transportation system, making full use of transportation condition, decreasing the transportation pollution, ensuring the traffic smooth and safe. However, the development of intelligent transportation system needs huge net and information of traffic, and have to get the realtime traffic data, The detection of traffic flow state is a fundamental problem which is related to the smooth operation of the road network, safe and efficient.This paper focus on the traffic detection in the intelligent transportation system. It’s a important technology in the process of the intelligent transportation system, the accuracy of traffic data is the key of intelligent transportation system. This paper design a embedded loop vehicle detector system based on STM32, parts of hardware include master control moduel, LC oscillating circuit, shaping circuit, serial interface module, Ethernet interface module, frequency threshold adjusting circuit module and JTAG download circuit module, according to the time difference from two loop, it can calculate the car speed, the detecting way of double loop guarantee the accuracy of speed morely, meanwhile calculate the traffic flow. In part of software, the way of time division for the vehicle lane solve the signal question of loop to loop; In order to reduce the influence of environmental factors on the detection accuracy, the automatic refresh algorithm based on the reference frequency is used to update the reference frequency of the coil, this way makes the design have the ability of refreshing autoly; meanwhile the design use the way of double loop’s signal matching, improving the detection accuracy when the traffic is very crowded.The paper describes the theoretical model of vehicle detection system, and through the practice of the vehicle detection system, including the design of each module of the hardware circuit and MCU and PC software programming, especially the experimental results show that the system design is feasible, and the detection speed value and the vehicle flow rate is high, and the expected function can be realized. It has a certain significance to improve the vehicle detection technology of intelligent traffic.