MOTOR VEHICLE-DETECTING SYSTEM

摘要

A motor vehicle-detecting system not impairing scenic beauty of a place where the system is installed, having high detection accuracy with less possibility of mis-recognizing motor vehicles, and consuming less power. A sensor that detects infrared rays emitted from an object to be detected measures an input level value, and a sensing/processing portion determines the presence and absence of a motor vehicle by using the input level value obtained from the sensor. The determination is made as follows. That is, a background level is calculated based on an input level value given by infrared rays emitted from objects other than the vehicle, a value (comparative value) based on the difference between the input level value and the background level value and a threshold value are compared, and the determination is made based on a magnitude relation of the compared values. Using a sensor that passively senses infrared rays enables the system to consume less electric power and ensures detection accuracy is prevented from being impaired even when infrared ray sensing is performed from a side of a vehicle.