红外测量在车流量监测中的应用

Application of Infrared Measurement in Flow Rates of Vehicles

介绍了基于红外传感器的车流量监测系统的总体方案以及软硬件设计。说明了红外传感器的选择以及菲涅尔透镜应用。红外传感器经过两级放大后,与窗口比较器进行比较产生脉冲进入单片机电路。通过对脉冲序列的分析和判断,得到通过车辆数。该系统采用红外传感器检测是否有车辆通过,可以将探头放置在公路的适当位置,车辆通过时会引起传感器输出的变化从而监测道路情况,测量该路段的车流量并将测量结果显示在屏幕上。文中说明了道路测试结果,并给出测试波形。阐述了车辆的计数流程图。并进行了车流量监测系统显示程序设计。本系统的软件设计部分用C51编写,设计程序实现了液晶屏显示等功能,C语言与汇编语言相比其可读性更强,使用也更简洁。在车流量监测系统中,基于红外传感器能够较好地实现了车流量的显示。

A kind of system including software and hardware design which is used to monitor the flow rates of vehicles based on the infrared sensor is included. The choice and the application of lens are illustrated. After the signals of infrared sensor are magnified and compared, the generated pulse comes into MCU. Through analyzing and judging the pulse sequences, the number of vehicles can be obtained. The principle of this system is to detect whether the vehicles has passed by using pyroelectric infrared sensor. Puting the infrared detector on an appropriate position on the needed road, the output of the sensor would give rise to change because of the variation of the passing vehicles. We can get the measured result ,and see the approximate statistics of the passing vehicles from the display of this instrument. Compared with assembly language, the software design of this system accomplishes many functions. Because of using c language as its software program, this system has stronger readability, easier usability and is also more convenient in modifying some data in the program. In monitoring and measuring system of flow rates of vehicles, the display of flow rates of vehicles can be realized based on infrared sensor effectively.