Pre-Collision Safety System

System Diagram:

SYSTEM DESCRIPTION




1. PRE-COLLISION SAFETY SYSTEM
a. The pre-collision safety system optimizes the occupant protection equipment (seat belt) and activates related systems to reduce damage from the collision.
b. Operation pattern and each operation of pre-collision safety system

1. Operation when operating with sensor
The pre-collision sensor (millimeter wave radar sensor) detects vehicles or other objects on the road in front. The cruise control ECU assembly (distance control ECU) determines in advance that a collision is unavoidable based on object position, speed and track information. The cruise control ECU assembly (distance control ECU) transmits unavoidable collision information through CAN communication. The seat belt control ECU receives the signal (from the cruise control ECU assembly (distance control ECU)) and initiates control of the pre-collision seat belts. The ABS & Traction actuator assembly (skid control ECU) also receives unavoidable collision information from the cruise control ECU assembly (distance control ECU) and activates the pre-collision brake assist system. The suspension control ECU also receives unavoidable collision information and hardens the suspension as much as possible.
2. Operation when operating with sudden braking
The ABS & Traction actuator assembly (skid control ECU) determines when the driver brakes suddenly according to brake pressure information, etc. The ABS & Traction actuator assembly (skid control ECU) sends the operation demand signal to the seat belt control ECU through CAN communication and activates the pre-collision seat belt.

2. OUTLINE OF PRE-COLLISION SEAT BELT CONTROL
a. The pre-collision seat belt operates with the sensor or sudden braking. The pre-collision seat belt motor tightens the seat belt to optimize occupant restraint performance.
b. Operative condition

1. When operating with sensor:
The pre-collision sensor (millimeter wave radar sensor) detects objects and the cruise control ECU assembly (distance control ECU) determines that a collision is unavoidable.
2. When operating with sudden braking:
The driver brakes suddenly and the ABS & Traction actuator assembly (skid control ECU) determines it as sudden braking.
3. The operation demand signal is received using a hand-held tester.

3. OUTLINE OF PRE-COLLISION BRAKE ASSIST SYSTEM
a. The pre-collision brake assist system operates with the sensor and enters standby mode before a collision. Brake fluid pressure is increased to simultaneously improve fluid pressure response and reduce vehicle speed when the driver depresses the brake pedal.
b. Operative condition

1. When the driver depresses the brake pedal after the cruise control ECU assembly (distance control ECU) determines that a collision is unavoidable: Brake fluid pressure is increased at the same time that the driver depresses the brake pedal after the pre-collision sensor (millimeter wave radar sensor) detects possible collision objects and the cruise control ECU assembly (distance control ECU) determines that a collision is unavoidable.
2. When the driver depresses the brake pedal before the cruise control ECU assembly (distance control ECU) determines that a collision is unavoidable: Brake fluid pressure is increased at the same time that the cruise control ECU assembly (distance control ECU) receives the information of an unavoidable collision after the pre-collision sensor (millimeter wave radar sensor) detects possible collision objects.

4. OUTLINE OF DAMPING FORCE CONTROL
a. The damping force control operates with the sensor, and the suspension is hardened as much as possible to reduce damage from the collision.
b. Operative condition

1. The pre-collision sensor (millimeter wave radar sensor) detects possible collision objects, and the cruise control ECU assembly (distance control ECU) determines that a collision is unavoidable.




5. OPERATIVE CONDITION AND INOPERATIVE CONDITION OF EACH CONTROL (REVIEW)
6. PRECAUTION FOR PRE-COLLISION SAFETY SYSTEM OPERATION




a. When the millimeter wave radar sensor detects an object in front under the conditions described, the cruise control ECU assembly (distance control ECU) may determine that a collision is unavoidable, and operate the pre-collision safety system. However, this is not abnormal.






HINT: The millimeter wave radar sensor might not be able to detect the objects as collision objects