COLLISION AVOIDANCE METHOD FOR CAR AT LOW-SPEED AND SHORT DISTANCE AND COLLISION AVOIDANCE APPARATUS THEREOF

摘要

PURPOSE: A collision prevention method for a car and a device thereof are provided to prepare for the malfunction of a laser sensor by enabling a front ultrasonic wave sensor to replace the function of the laser sensor. CONSTITUTION: A distance with a front car is calculated by using return time generated by enabling a laser sensor to emit a laser beam to the front car and by receiving the reflected laser beam (S1). A front ultrasonic wave sensor senses the front car which is close to a car by emitting an ultrasonic wave to the front car (S2). A side ultrasonic wave sensor senses a side car which is close to the car by emitting the ultrasonic wave to the side of the car (S3). The distance with the front car is obtained (S4). A distance change ratio with the front car is obtained (S5). The speed of the car is obtained (S6). The speed change ratio of the car is obtained (S7). Output information which is sensed by the front ultrasonic wave sensor is obtained. A collision risk degree is obtained by using the distance with the front car, the distance change ratio with the front car, the speed of the car, and the speed change ratio of the car (S8). A risk degree indicates the necessary of speed reduction function in the car which is predicted to collide with other cars. A collision risk degree is obtained by dividing collision degrees indicating a necessary state of a speed reduction function for avoiding collision.