System for preventing collision of vehicles

DETAILED DESCRIPTION Accordingly, it is an object of this invention to provide an improved system for preventing collision of a vehicle utilizing a single antenna type pulse radar system which can ensure the operation of the brake actuate to positively stop the vehicle even when the vehicle approaches close to an obstacle and enters into a blind zone of the radar system.
According to this invention, there is provided a system for preventing collision of a vehicle, comprising a radar system mounted on the vehicle for generating a relative speed signal representing the relative speed between the vehicle and an obstacle and a relative distance signal representing the relative distance between the vehicle and the obstacle, a brake signal generating logical circuit to be driven by the relative speed signal and the relative distance signal, a first comparator for comparing the relative speed signal with a first reference value, a second comparator for comparing the relative distance with a second reference value, an information processing circuit responsive to the output from either one of the logical circuit and the first and second comparators, for actuating a brake actuator of the vehicle, and a brake releasing circuit for disenabling the brake actuator after the vehicle has stopped.