Object Detection Description and Operation (UD7): Notes

WARNING: This page is about a different car, the 2012 GMC Terrain and 2012 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.

The ultrasonic rear parking assist system is designed to identify and notify the driver of an object in the vehicle's path when reversing at speeds of less than 8 km/h (5 MPH). The distance and location of the object is determined by 4 object sensors located in the rear bumper. The parking assist system will notify the driver using the parking assist indicators and an audible beep signal through the radio.

The rear parking assist system is made up of the following components:

Parking assist control module
Rear object alarm sensors
Parking assist indicator

Parking Assist Control Module

The parking assist control module provides an 8 V reference and a low reference to the four rear parking assist sensors. The parking assist control module receives individual signals from each of the four sensors and determines the location and distance of an object based on these inputs. When an object is detected, the parking assist control module will illuminate the appropriate LED on the parking assist indicator and send a serial data message to the radio requesting an audible alert.

Rear Object Alarm Sensors

The rear object alarm sensors are located the in rear bumper of the vehicle. The sensors are used to determine the distance between an object and the rear bumpers. Each sensor emits an ultrasonic frequency which is reflected off object located behind the vehicle. These reflections are received by the sensors. The time difference between when the frequency was emitted and when the reflection is received, known as sensor echo time, is used to determine the distance to the object. The sensors report this information to the parking assist control module.

Parking Assist Indicator

The parking assist indicator is located in the interior rear of the vehicle and is visible through the inside rearview mirror. The indicator contains three LEDs: two amber and one red. The parking assist control module controls these three LEDs as a visual indicator of how close the vehicle bumper is to an object. The parking assist control module supplies voltage to each of the LEDs and commands each LED on by supplying an individual ground.