基于地磁传感器的车流量智能检测系统设计

道路流量信息是进行有效交通管制和引导的重要依据。针对现有的无线地磁车流量检测系统取电难、通信不稳定的问题,结合近期国内多地应用的道路交通发光砖,设计了一种车流量实时检测系统。系统通过嵌入在地砖中的检测器完成车辆检测,数据经由RS485总线汇总至上位机,并上传至服务器。检测器利用RM3100传感器采集磁场原始信号,在STM32中通过双窗口法提取出车辆的特征波形;采用自适应阈值有限状态机算法,判断车辆的运动状态。经过实地安装测试,检测器识别车辆的准确率可达97%左右,系统运行稳定可靠,对构建智慧交通道路体系具有一定的实用价值。

Design of Intelligent Traffic Flow Detection System Based on Geomagnetic Sensor

Traffic flow information is an important basis for effective traffic control and guidance.To solve electricity acquisition and unstable communication in existing wireless geomagnetic traffic flow system,a real-time traffic flow detection system is designed in combination with luminous road bricks used in many cities in China recently.Vehicle detection is accomplished by detectors embedded in bricks.Data are summarized to the upper computer through RS485 bus and uploaded to the server at the same time.Detectors collect original signals of magnetic field through RM3100 and extract characteristic waveforms of vehicles by a double-window algorithm in STM32.An algorithm of finite state machines with adaptive thresholds is applied to identify the movement state of vehicles.Upon on-site installation and test,the detectors can recognize vehicles with an accuracy rate of about 97%and the system remains stable and reliable.The results show that the system has a certain practical value for the construction of intelligent transportation system.