15-09-2017, 12:37 PM
This system consists of ultrasonic sensors, namely, ultrasonic wave emitter and ultrasonic wave receiver. The ultrasonic wave emitter is provided at the front of the car, producing and emitting ultrasonic waves at a predetermined distance in front of the car. The ultrasonic wave receiver is also provided in the front of the car, receiving the ultrasonic wave signal reflected from the obstacle. The reflected wave (detection pulse) is measured to obtain the distance between the vehicle and the obstacle. Next, the PIC microcontroller is used to control the servomotor based on the detection pulse information, and the servomotor automatically controls the braking of the car. This work demonstrates the possible use of an accelerator pedal disconnect mechanism in this system, whereby the accelerator pedal is automatically disconnected once the braking is started. Thus, even if the acceleration pedal is pressed the vehicle will not accelerate and this will avoid collision. This solves the safety problem in case the accelerator pedal is depressed when the vehicle is expected to brake.