Parking Sensor System

Parking sensor systems use ultrasonic proximity detectors embedded in the front and/or rear bumpers, to measure the distances to nearby objects at low level. The sensors measure the time taken for each sound pulse to be reflected back to the receiver. Depending on the speed of the vehicle and the distance to the obstacle, the system will warn the driver by visual and/or audible means about the risk of collision. The feedback to the driver will generally indicate the direction and proximity of the obstacle.
Sensors are usually fitted to the rear of a vehicle but may also fit to the front. Rear sensors are activated when reverse gear is selected and then deactivated as soon as any other gear or neutral is selected. Front sensors are generally activated by pressing a button and then automatically deactivated when the vehicle exceeds a certain speed, this is to avoid nuisance warnings in slow moving traffic.