What does AEB automatic emergency braking system mean and how does it work?

Basic Concepts

AEB stands for Automatic Emergency Braking

The system uses radar and cameras to monitor the vehicles and pedestrians ahead. If a potential collision risk is detected, the system will take corresponding warning and braking measures to avoid a collision or reduce the degree of collision damage.

Working process

The first stage of the first-level warning, visual and sound reminders, shock absorption adjustment, enter the pre-braking state

Second stage, secondary warning, warning adjustment of shock absorber, brake reminder

The third stage of comfort braking, double lights are on

Stage 4: Seat belt pre-tensioning, full braking

Hardware Architecture

The hardware mainly consists of three parts: sensor, controller and actuator

sensor

The environmental perception sensors used in the current mainstream AEB solutions are millimeter-wave radars and cameras: millimeter-wave radars obtain the distance, speed, and angle of the target object by sending electromagnetic waves to the target and receiving echoes; the camera needs to first identify the target and then estimate the target distance based on the pixel size of the target in the image.

Controller

Currently, AEB controllers are mostly integrated into sensors (mostly millimeter-wave radars). With the continuous development of intelligent driving technology, AEB control functions will gradually be taken over by domain controllers.

Actuator

Currently, the actuators of AEB are all electronic stability programs (Electronic Stability Program, referred to as ESP)

The system consists of three parts: sensors, electronic control units (ECUs) and actuators. The ECU monitors the vehicle's operating status and intervenes in the vehicle's engine and brake system. A typical automotive electronic stability control system mainly includes four wheel speed sensors, a steering wheel angle sensor, a lateral acceleration sensor, a yaw rate sensor, a brake master cylinder pressure sensor, etc. The actuator includes a traditional brake system (vacuum booster, pipelines and brakes), a hydraulic regulator, etc. The ECU is linked to the engine management system to intervene and adjust the engine power output.

AEB five safety distance models

Currently, the main safety distance models include the Mazda model, Honda model, Berkeley model, SeungwukMoon model, and TTC model.

The automatic emergency braking system monitors the distance and relative speed of the target ahead. When the driver brakes too late, the braking force is too small, or there is no braking action at all, the system will take measures to assist the driver in avoiding or mitigating a collision. The AEB system consists of two modules: warning and emergency braking.

The sensors used by the AEB automatic emergency braking system are:

1. Front camera

2. Medium-range radar

Automatic emergency braking with three assist modes

The automatic emergency braking system is a safety system that is turned on by default during each ignition cycle. When the system determines that a danger has occurred, it will assist the driver in the following ways:

1. Predictive Collision Warning

When the vehicle speed reaches 30 km/h or above, the system considers that there is a potential risk of collision and will remind the driver of the potential risk of collision through alarm sounds and alarm pictures on the instrument interface.

2. Emergency Brake Assist

When the vehicle speed reaches 4 km/h or above, if a dangerous situation occurs but the driver's current braking force is too small, the system will assist the driver to increase the braking force to avoid or reduce the collision.

3. Automatic emergency braking

When a dangerous situation occurs and the driver does not respond effectively, the system will intervene in time and perform automatic emergency braking to avoid or mitigate the collision. Automatic emergency braking can reduce the speed by up to 50 km/h.

When the function is activated

When driving at medium or high speed and following the vehicle in front too closely, the following picture and text prompt will appear on the instrument cluster:

When the AEB system is triggered, the following picture and text prompts will appear on the instrument cluster, accompanied by an alarm sound.

Automatic emergency braking system prompts when the vehicle is in motion before a potential collision occurs (as shown below)

False trigger classification

Automatic emergency braking system for pedestrians

The pedestrian automatic emergency braking system can avoid or reduce collisions with pedestrians. Main application scenario: pedestrians crossing the road. The pedestrian pre-alarm function will use sound and pictures to remind the driver to respond in time to reduce the risk of collision when a collision risk is detected. This function works at a speed of 4-70 km/h.

When the AEB system's pedestrian function is triggered, the following picture and text prompt will appear on the instrument cluster display, accompanied by an alarm sound.

NOTE: Pedestrian Automatic Emergency Braking is not available if the front camera is obstructed or if the front camera functionality is limited.

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