Object Detection Description and Operation PIDS

The pedestrian impact detection system (PIDS) primary function is to provide supplemental protection to vulnerable road users involved in vehicle impacts. The PIDS is also known as the active pedestrian protection system (APPS). The PIDS is a functional system for raising the hood to provide sufficient vertical deformation space under the hood. In Europe and Japan an active PIDS is necessary for vehicles which do not provide the required deformation space under the hood. The PIDS includes the following components

The PIDS will sense and discriminate vulnerable road user impacts and deploy the hood hinge actuators in a timely manner to protect the pedestrian. The term "deployment" applies to the activation of the hood via the hood actuators. The PIDS is designed to sense and discriminate road user impacts (eg. pedestrian, cyclist) from other types of impacts in order to properly deploy the hood actuators. No actions or inputs are required from the driver or passenger to trigger this device. The PIDS module uses the safing and discrimination sensor to get acceleration and force information needed for the deployment of the hood hinge actuators. The PIDS module deploys the hood actuators using two deployment loops. The PIDS only operates at vehicles speeds between 27 km/h (16 mph) to 45 km/h (27 mph). The PIDS module detects internal and interface faults and commands the Service Pedestrian Protection System message in the DIC to indicate a system fault.

After a deployment event, the vehicle operator is able to reset the hood to its normal driving position. After resetting the hood, the PIDS is not required to be fully functional. For full functionality, it is necessary to replace system component(s) at an approved service facility.

Safing Sensor

The safing sensor provides vehicle acceleration information to the pedestrian impact detection system (PIDS) module. The safing sensor uses an independent electronic safing method acting through an independent logic circuit such that no single point failure can lead to an unwanted actuation of the hood. The PIDS module provides a two wire current loop interface to the safing sensor. The PIDS module also provides power and ground to the safing sensor over the same two wire discrete interface.

Discrimination Sensor

The discrimination sensor provides discrete force information to the pedestrian impact detection system (PIDS) module. The PIDS module uses measurable pedestrian impact data sent from the discrimination sensor to determine the severity of the impact. The PIDS module provides a two wire current loop interface to the discrimination sensor. The PIDS module also provides power and ground to the discrimination sensor over two separate discrete circuits.

Hood Hinge Actuators

The pedestrian hood actuators deploy only when a valid signal whose energy is capable of triggering deployment of the hood is present. The pedestrian hood actuators only deploys in those events where the activation of the hood is expected. The hood actuator is not expected to deploy in low severity event where the risk of injury is low or in a high severity event like car to car crash. During a frontal pedestrian impact of sufficient force, the PIDS module will allow current to flow through the deployment loops in order to deploy the hood hinge actuators. The pedestrian impact module also performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity, shorts to ground and shorts voltage. In order to prevent unwanted deployment of the actuator during service, the hood hinge actuator contains 2 shorting bars that will short both high and low circuit pins when disconnected. The PIDS module only issues a deployment command when a valid safing signal or confirmation has been generated. No inadvertent deployments will occur in any deployment loop due to a single point fault.

Object Detection Description and Operation Rear Parking Assist

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 signal through the radio.

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

Object Alarm Module

The object alarm module provides an 8-volt reference and a low reference to the four rear parking assist sensors. The object alarm 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 object alarm 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 Parking Assist Sensor

The parking assist 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 ring time, is used to determine the distance to the object. The sensors report this information to the object alarm 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 object alarm module controls these three LEDs as a visual indicator of how close the vehicle bumper is to an object. The object alarm module supplies voltage to each of the LEDs and commands each LED on by supplying an individual ground.

When the vehicle is first placed into reverse, the rear parking assist system performs a bulb check. During the bulb check, the all three LED located in the parking assist indicator will illuminate for approximately 2 seconds to indicate that the system is working.

When backing up at speed of less than 8 km/h (5 mph), the system is constantly monitoring for object of interest located behind the vehicle. The rear parking assist system can detect objects greater than 7.6 cm (3 in) wide and 25.4 cm (10 in) tall. The system cannot detect objects below the bumper, underneath the vehicle. If an object is detected, one of the following will occur:

If the rear parking assist system detects a malfunction, a DTC will be stored and the object alarm module will send a serial data message to the instrument panel cluster (IPC) to display the SERVICE PARK ASSIST message on the driver information center (DIC). A chime will sound and the red LED on the parking assist indicator will be illuminated. as a notification to the driver that a malfunction exists and the system is disabled.

SERVICE PARK ASSIST

The driver information center (DIC) displays SERVICE PARK ASSIST when the object alarm module detects a malfunction in the rear parking assist system and the system is disabled. The DIC also displays SERVICE PARK ASSIST when a loss of communication occurs with the object alarm module.

PARK ASSIST OFF

The PARK ASSIST OFF message is displayed in the DIC when the object alarm system is disabled due to conditions that disable or inhibit the system. The red LED in the park assist indicator will be illuminated to indicate that the system has been disabled. The object alarm module requests the DIC display PARK ASSIST OFF when it detects that one of the following conditions: