Collision Avoidance and Parking Assist Systems: Description and Operation

PARKING AID

The parking aid system sounds a warning to alert the driver of stationary objects near the rear bumper when the REVERSE gear is selected. The parking aid system assists the driver in detecting certain objects while the vehicle moves slowly in REVERSE at speeds less than 4.8 km/h (3 mph). The parking aid system may not detect angular or moving objects.

PRINCIPLES OF OPERATION

When active, on rear parking aid systems, the rear sensors are activated at all times when the transmission is in REVERSE. For front and rear parking aid systems, the front and rear sensors are always active in REVERSE. When the transmission is in DRIVE, the front sensors are active if the vehicle speed is above 0 km/h (0 mph)and below 8 km/h (5 mph). If the vehicle is in DRIVE and has a speed of 0 km/h (0 mph), the front sensors will only be active for 5 seconds before being deactivated.

An ultrasonic field is emitted in a semicircular area around the front and the rear of the vehicle. The parking aid sensors can detect objects approximately 1.8 m (5.9 feet) to the front or rear of the vehicle, 60 cm (1.7 feet) on front and rear systems to the front side of the vehicle and 50 cm (1.6 feet) on rear systems only to the rear side of the vehicle, and 16 cm (6 inch) above ground. A 750 Hz variable warning tone is generated from both parking aid speakers. The parking aid speakers increase their warning tone rate as the vehicle gets closer to an obstacle. When an object is detected within 25 cm (10 inch) of the sensors, the warning tone becomes continuous. For the rear sensors, when an obstacle is detected only by the outer sensors and the distance between the obstacle and vehicle does not change in 3 seconds, the object will not be reported. This will be referred as the 3 second time-out hereafter. The 3-second time-out will be incorporated into both the rear and front and rear system.

The system is functional with the ignition in RUN. A system ON/OFF switch allows the driver to enable or disable the parking aid system when the ignition is in RUN. This switch is a momentary type. The system enables on every ignition switch transition to RUN. The switch has an indicator which is used to indicate when the system is enabled, disabled, or a failure condition exists.

The indicator located in the switch constantly illuminates when the momentary switch is pressed and the system is disabled. When the system is enabled, the indicator is not illuminated. Graphics on the switch represent parking aid OFF.

When the ignition switch transitions to RUN and no faults are active, the parking aid module proves out the indicator, located in the system ON/OFF switch, by constantly illuminating the indicator for a period of 3 seconds. If a failure condition exists, on ignition switch transition to RUN, the failure indication described below shall begin.

If the control module detects a failure in the parking aid system, it lights the indicator located in the system ON/OFF switch. The indicator is constantly illuminated while the failure condition exists and the ignition is maintained in RUN. The indicator extinguishes when the ignition transitions from RUN or the failure condition no longer exists. During a failure condition, the parking aid system is disabled and will not enable by a press of the system ON/OFF switch.