Development of a method to detect traffic volume by making use of high-sensitivity seismometers

提出了一种利用高灵敏度地震仪评价交通量的实用方法。该系统由高灵敏度地震仪、放大器、A/D转换器和微机组成。初步观测结果表明，竖向地震动在位移维度上最适合检测行驶车辆。当车辆速度足够高（约20 km/h或更高）时，可以通过地震仪的距离和到达时间差来准确地评估行驶速度。由于感应子波的宽度随着运行速度的增加而变窄，因此实际上可以从在一个地震仪上记录的子波来评估运行速度。当车速较低（约10 km/h或更低）时，无法观察到明显的子波。然而，当一个小的橡胶凸块临时安装在道路上，诱导一个显着的小波。从速度维分析子波，可以很容易地检测到子波。在公共道路上的观测表明，诱导子波的形状与行驶车辆的质量有关。这种差异使我们能够区分车辆的类型。

A practical method to evaluate traffic volume is developed by making use of high-sensitivity seismometers. The system consists of high-sensitivity seismometers, amplifier, A/D converter, and personal computer. Preliminary observations show that vertical ground motion in displacement dimension is the most appropriate for detection of running vehicles. When vehicle speed is high enough (about 20 km/h or more), the running speed can accurately be evaluate with the distance of seismometers and the difference of arrival time. Because the width of induced wavelet becomes narrower as running speed becomes higher, running speed can practically be evaluated from a wavelet recorded at one seismometer. When vehicle speed is low (about l0km/h or less), significant wavelet cannot be observed. However, a significant wavelet is induced when a small rubber bump is temporarily installed on road. The wavelet can easily be detected when the wavelet is analyzed in velocity dimension. Observations in public roads show us that shape of induced wavelet is related to the mass of running vehicles. The difference allows us to distinguish the type of vehicles.