Introduction

The widespread introduction of the anti-lock braking system (ABS) has laid the foundation for various braking control systems. At the same time, sensors have been developed to detect obstacles, other vehicles, or pedestrians in the vehicle's vicinity. Automatic Emergency Braking System (AEBS), a combination of braking and sensor technology, is a system that automatically applies brakes in critical situations, reducing the severity of collisions. This article will explore how AEBS improves safety and reduces human effort in modern automobiles.

What is an automatic emergency braking system (AEBS)

An Automatic Emergency Braking (AEB) system is a safety mechanism integrated into automobiles to recognise and prevent crashes. The system employs cameras, sensors, and radar to keep track of the car's environment and identify potential barriers. Whenever the AEB system perceives an impending collision, it initiates the brakes automatically to decelerate or halt the vehicle.

How does AEBS work

An AEBS is a safety feature that automatically controls a vehicle during emergencies. The system uses sensors to monitor the distance between the car and the obstacles in front of it. If the sensors detect that a collision is likely to occur due to the relative speed and distance between the two, the system will automatically apply emergency braking to prevent or minimise the impact of the collision, as shown in the figure below.

AEBS can reduce the impact of various crashes, including head-on, rear-end, right-turn, and pedestrian collisions. Automatic Emergency Braking (AEB) is a unique generation of Advanced Driver Assisted System (ADAS) that operates on the principle of electronically controlled Ultrasonic Sensors that analyse and measure the speed of the approaching vehicle, enabling the AEB system to function.

The most common factors that lead to accidents are poor visibility, ignoring traffic signals, and not maintaining a safe distance from other vehicles. AEBS relies on Vehicle-to-Vehicle (V2V) communication to mitigate the effects of high-speed collisions and reduce them to low-speed impacts.

Figure 1: Working principle of AEB system

These systems initially notify the driver to take action to avoid a collision. The system does this through an audio signal, an alert on the display screen, or by tightening the seat belts. If the driver's steering and braking are insufficient to prevent the collision, the automatic emergency braking system will automatically apply the brakes.

Technology configuration / parts of AEBS

Automatic emergency braking (AEB) systems use sensors, software, and hardware to detect potential collisions and apply the brakes automatically if the driver does not respond. These systems differ in their specific technology, but standard components include:

• Radar sensors emit radio waves to detect objects in front of the vehicle and calculate the distance and speed of nearby obstacles.
• Lidar sensors use lasers to create a detailed 3D map of the vehicle's surroundings, providing more accurate information about nearby objects' size and shape.
• Imaging and stereo cameras provide visual input of the vehicle's surroundings, detect objects, and identify pedestrians and other vehicles, providing additional information such as the speed and direction of objects.
• Ultrasonic sensors emit high-frequency acoustic waves to detect obstacles at close range, determining their distance and location.
• An electronic control module processes data from the sensors, using algorithms and decision-making software to assess collision risk and calculate the appropriate response.
• A braking system (actuators) relies on the vehicle's braking system, or a separate brake actuator designed for AEB to apply the brakes when necessary.