【作者】 桑兆辉；

【导师】 石满华；

【作者基本信息】 河北工业大学 ， 应用数学， 2003， 硕士

【摘要】 本课题设计的是一种悬挂式超声波车流多信息检测器，通过悬挂于路面上方的超声波探头向路面周期性地发射脉冲信号，利用地面回波来判断遮挡物地存在，可用于检测行驶中的机动车车速、车高、车长、大中小分型以及累计车流量、车队长度等信息，并可用于多个车道车流信息的同时检测，综合这些测量参数可获得车流量的必要数据，可为公路建设提供必要的基础依据。 主要技术特点： 1． 采用多探头结构，多个探头之间相互之间有一定距离和交织发射角度，对准同一个被测物体的反射面，可使检测范围内的每一个固定点上反射面的可测方位个数较单探头有所增加，可大大降低回波漏检率； 2． 自动标定超声波探头的架设高度，探头与地面间有无遮挡物的判断以地面回波为基准； 3． 在超声波接收电路中设有信号触发锁定电路和时基控制电路。实现以各探头中最早收到的回波信号为本检测单元的有效信号，有效提高信噪比和检测精度； 4． 在软件中设计了数据抗干扰处理模块(数据滤波)，提高系统的抗干扰能力； 5． 信息融合单元连接多个检测单元(探头)，同时检测多个车道的车流信息： 6． 在软件中设计了模糊识别累计车流量模块，可排除行人或非机动车、摩托车作为遮挡物可能造成的计数干扰，大大提高计数准确度。 目前有关超声波车流检测器的文献较多，但本设计中采用的多探头结构、自动标定超声波探头的架设高度、数据滤波以及多车道测量和检测车队长度等技术在同类设计中未见使用。更多还原

【Abstract】 The subject of this design is a suspension-type of ultrasonic detector for vehicles’ traffic data. In principle, ultrasonic sensors are suspended over a road, which keep emitting pulse signals periodically to nearby and feed back waves to decide existence of any obstacles, thus to detect the speed, height, length, different sizes (heavy, medium and small) of moving vehicles and accumulative flow as well as length of motorcade. Optionally, it can be applied to multitude driving lanes simultaneously for traffic data. By integrating and analyzing these measured data, the necessary figures concerning traffic flow may be obtained, which are fundamental basis guiding road buildings.This design has distinctive technical features as follows:1. Applied Multi-sensor construction. Well-calculated distance and crossing angles between sensors aiming at a same target makes it possible to acquire more accurate back waves than single sensor construction. Consequently, error rate is reduced significantly.2. Able toe stablish the d arum 1 ine automatically r egardless o f t he h eight o f s ensor suspended above the road. The obstacle is detected based on the back wave reflected from road surface.3. Arranged signal activating lock circuit and time-base control circuit in the sound wave receiving circuit to take the initial signal of back wave as the valid one in the cycle, thus to improve the ratio of signal vs. noise and detective precision.4. Integrated disturbance-resistant datum module (digital filtering) to strengthen the anti-disturbance capacity of the system.5. Able to detect the traffic data from multiple lanes simultaneously by connecting several detecting units (sensors) with one central processing unit.6. Designed fuzzy recognition module in the software to screen out the disturbancefrom pedestrians, non-driven vehicles and motorcycles for higher counting accuracy.Although there are many literatures describing ultrasonic detector for traffic flows, none of the same category has referred the techniques applied in the design herein such as multi-sensor construction, automatically establishing datum line regardless of suspension height, digital filtering and multi-lane detection as well as measuring length of motorcade.更多还原