Method of installing wave frequency detector on roadside to detect traffic flow

Abstract

The invention discloses a method for installing a wave frequency detector at a roadside to detect traffic flow. The method comprises the following steps of: installing the wave frequency detector at one side of a vehicle road; enabling a wave beam sent out of the wave frequency detector to be opposite to the side face of a vehicle to be detected; and determining the existence and the position of the vehicle by the wave frequency detector through the existence of an echo and the time of the echo. The wave frequency detector is installed at the roadside, so that the weakness that the installing cost is high, and the traffic can be inflected and even be interrupted caused by the installation and maintenance since a probe needs to be installed above each lane of an overhead type ultrasonic detector can be overcome; and the wave beam of the wave frequency detector is over against the side face of the vehicle to be detected, and the echo of the vehicle to be detected is a normal reflection wave, so that the weakness that existence of vehicle existence is determined by mistake when the speed of the vehicle is slow and in the process of traffic jam since the echo takes the non-normal reflection wave as a main part, the echo is very complex to determine, and the echo is extremely false to determine caused by a larger inclined angle between the wave beam of the current wave frequency detector arranged at the roadside and the road surface can be overcome, and the requirement that the detectors need to be intensively installed since the current road traffic condition is jammed day by day can be met.

Description

technical field [0001] The invention relates to the technical field of detecting road motor vehicle flow, in particular to a method for installing a wave frequency detector on the roadside to detect traffic flow. Background technique [0002] Traditional wave frequency detectors, such as ultrasonic traffic flow detectors, are top-mounted, with one or two probes installed in each lane, and the probes emit ultrasonic beams vertically downward to detect vehicles passing under the probes. Its advantage is that the detection is not blocked, it can still detect accurately when the traffic density is high, and it can distinguish various types of vehicles. The disadvantage is that the installation requires a special gantry, the installation cost is high, the installation and maintenance will affect or even interrupt the traffic, it is easy to miss the detection of vehicles that do not drive according to the road, and the simultaneous operation of multiple probes is easy to cause int...

AI Technical Summary

Problems solved by technology

Compared with the top-mounted ultrasonic detector, its advantage is that it is installed on the roadside, the installation cost is low, and the installation and maintenance will not affect the traffic; the disadvantages are: 1) The side-mounted detection may be blocked; 2) The beam is wider (generally greater than 2 meters ), when the traffic density is high, the vehicles cannot be segmented correctly, resulting in misjudgment; 3) The beam is emitted downward at a certain inclination (such as figure 1 ), the vehicle and the ground have echoes, because the beam cannot face the reflecting surface, the echoes are mostly refracted waves and scattered waves, the echoes are complex, difficult to deal with, and easy to cause misjudgment, especially when the vehicle speed is low or there is a large area of ​​traffic jam. The vehicle is often misjudged as the road surface, and the traffic jam is judged as no car; 4) Due to the installation height and installation inclination angle, in order to avoid detecting dead angles, the installation needs to be retracted (such as figure 1 , about 5 meters), which is not conducive to the installation and use in special environments such as bridges and tunnels

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