Active Safety System Description and Operation (UGN): Notes

The active safety system is a comprehensive feature set designed to help a driver avoid collisions or reduce crash damage while driving. The K124 Active Safety Control Module is the primary controller for the active safety system. The K124 Active Safety Control Module communicates on multiple serial data busses to share information with various control modules throughout the vehicle. The K124 Active Safety Control Module uses various sensors and control modules to monitor the vehicle surroundings and take deliberate action to avoid collisions or reduce crash damage. The active safety system tightly integrates the forward collision alert, adaptive cruise control, and active emergency braking systems into a single cohesive system.

The K124 Active Safety Control Module communicates via serial data on the object detection bus with the B174W Frontview Camera - Windshield and B233B Radar Sensor Module - Long Range to create a virtual fusion image of the area in front of the vehicle. The K124 Active Safety Control Module observes an actual visual image of the area directly ahead of the vehicle, within 60 m (197 ft), with the B174W Frontview Camera - Windshield. The B233B Radar Sensor Module - Long Range is used to measure the distance to objects that are up to 200 m (656 ft) in front the vehicle. Within 60 m (197 ft) of the vehicle, all of these inputs are combined to create a fusion image of the area in front of the vehicle. At up to 200 m (656 ft), the B233B Radar Sensor Module - Long Range will detect and begin tracking objects immediately in front of the vehicle. Within 60 m (197 ft), the B174W Frontview Camera - Windshield will confirm objects that have been detected by the B233B Radar Sensor Module - Long Range.

The fusion image created by the K124 Active Safety Control Module is used to detect collision risks and take action based on the immediacy of the risk. The a collision risk exists, the K124 Active Safety Control Module will alert the driver using the forward collision alert system. This will provide the driver with a visual and audible alert that a collision risk has been detected. If the driver does not take action to reduce the risk of collision, such as changing lanes or applying the brakes, the intelligent brake assist system will pre-fill the brake hydraulic system to reduce system response time and increase pressure when quickly applying the brakes. If a collision risk is imminent, the K124 Active Safety Control Module will enter automatic collision preparation, which will automatically apply the brakes in an effort to mitigate the collision or reduce collision damage.

The K124 Active Safety Control Module communicates with the B99 Steering Wheel Angle Sensor and the B119 Multi-axis Acceleration Sensor via serial data on the chassis expansion bus. These sensors are used to determine the intended vehicle path. Using the steering data and vehicle acceleration data, the K124 Active Safety Control Module will determine where the vehicle will be traveling and focus attention on objects in this path. An example would be a driver quickly changing lanes to avoid a collision. This would mitigate the collision risk in the previous lane and the K124 Active Safety Control Module would quickly transition to tracking objects for any collision risk in the new lane based on intended vehicle path. The K124 Active Safety Control Module also communicates with the K17 Electronic Brake Control Module to instigate the braking functions of intelligent brake assist and automatic collision preparation.

The Active Safety System analyzes data from the various control modules and sensors listed below:

• K124 Active Safety Control Module
• B174W Frontview Camera - Windshield
• B233B Radar Sensor Module - Long Range
• K17 Electronic Brake Control Module