In the smart parking industry, vehicle detectors are familiar to everyone. Due to different application technologies, they can be divided into toroidal coil vehicle detectors, ultrasonic sensor vehicle detectors, radar detection vehicle detectors, video detection vehicle detectors, etc.
Among them, the toroidal coil vehicle detector should be the most widely used. It buries the ground-sensing coil under the lane. When the vehicle passes by, it will cause the change of the coil magnetic field. The vehicle detector can calculate the vehicle flow, speed, vehicle length and other parameters according to the change of the magnetic field.
In the smart parking system, the ground-sensing vehicle detector mainly plays a triggering role to detect whether there is a vehicle on the lane. Because the ground-sensing vehicle detector technology is mature, easy to install, and low cost, it is widely used in the parking industry.
However, the ground-sensing vehicle detector also has shortcomings, mainly manifested in:
1. The ground-sensing coil needs to be buried under the lane, so the installation of this vehicle detector requires cutting the road surface, which will cause traffic obstruction.
2. Because the road surface needs to be cut, the cutting seam will destroy the road surface structure and the road surface damage will be aggravated.
3. The ground sensor coil is easily affected by the environment, such as freezing, roadbed subsidence, salinity, etc.
4. When there are many vehicles and the distance between vehicles is less than 3 meters, the detection accuracy will decrease.