Autonomous emergency braking is an advanced driver assistance system (ADAS) and safety technology.
Autonomous emergency braking (AEB) is a system that performs emergency braking when the driver does not expect or react to an obstacle, emergency vehicle or pedestrian.
Forward-facing cameras and radar sensors (which work using radio waves) are the core components of AEB systems. In AEB systems, the camera has a range of about 300m and the radar can detect objects with a minimum distance of 30 metres in front under ideal conditions.
The advanced driver assistance system calculates when to start braking based on factors such as speed, situation awareness, and avoidance maneuver. Depending on the manufacturer it also takes into account whether the obstacle is an animal or another car, motorcycle or bicycle. If other cars are involved, AEB systems do not perform full braking due to the risk of causing other incidents, so there is enough force applied to stop the car and prevent collisions.
Current AEB systems are mostly based on visual and radar sensors. LIDAR, on the other hand, has a range of about 200 meters which can be further increased with a laser range finder on top of the sensor to 400 metres.
Currently, camera-based AEB systems have limited capabilities due to the limited field of view of the camera. In everyday driving situations, it might not be possible for the system to assess the situation early enough to start braking before impact is inevitable. Radar or laser sensors provide better circumstances awareness but their operation is limited by conditions such as heavy rain that absorbs both reflected light from objects and emitted waves from the sensor itself. For more information on other types of vehicle safety features, take a look at the New South Wales State Government's guide.There are various types of advanced driver assistance systems available on new cars today: blind spot assistant, parking assistants, lane-keeping support, adaptive cruise control, etc. It is difficult to give exact numbers, but I would say that at least 20% of new cars have some sort of advanced driver assistance system.
AEB is a generic term covering several systems that reduce speed or come to a complete stop in order to avoid or mitigate the consequences of an accident. There are many car manufacturers which have their own name for AEB systems: Hyundai has Smart Sense, Mercedes-Benz Active Brake Assist, Volvo Inclusive Protection, FIAT has City Brake Control, Ford has Active City Stop, and Volkswagen calls it City Emergency Braking. Early AEB systems were first installed in Honda cars. In case of autonomous emergency braking, cars fitted with AEB systems will do everything from sensing obstacles, pedestrians and vehicles ahead to bring your new car to a complete stop. By bringing you to a stop or ensuring that your car is driving at low speeds instead of driving fast, it helps curtail the risk of accidents.
It is safe to disable AEB systems. Most systems will still function if a sensor fails, for example. The more complex systems that rely on radar or laser sensors can get confused from obscuring factors such as rain or darkness and drivers might have to resume manual control of the car.
Autonomous emergency braking (AEB) is usually turned off via a button in the vehicle's menu system. It varies based on the models and manufacturers, so you should check your user manual in order not to miss out on critical safety technology and features such as:
City Emergency Braking (new models and cars with this include VW).
Pedestrian Detection (new models and cars with this include Mercedes-Benz and Volvo). It is worth noting that some cars may also combine cyclist detection with this feature.
Animal Detection (new models and cars with this include Mercedes-Benz, Volvo, BMW and Tesla Model S/X with Autopilot 2.0+).
There is no specific requirement for the autonomous emergency braking (AEB) system to work together with other systems on the vehicle.
Many AEB systems and most major car manufacturers use similar technology for systems that are based on radar and/or camera: Bosch, Continental, and Valeo (among others) sell multi-mode radars for this purpose. The sensor operates in two modes which can be selected depending on local conditions such as weather or road ahead (the road surface). In the high-frequency mode, the range of operation is longer but it cannot detect small objects such as pedestrians. In low-frequency mode, it can detect smaller objects but has a shorter range and can detect objects at short distances. It is typically used at higher speeds. At higher speeds, a less sensitive mode allows faster reaction times without compromising safety too much. The system will pick up pedestrians in the visual field of the camera and track them using an internal software algorithm, and ensure the speed of your car isn't so much that you'll crash into them. This helps ensure both car safety and city safety, and reduces risk to vulnerable road users.
Other sensor types used for AEB emit ultrasonic waves that reflect back from obstacles/vehicles ahead and the time taken is used to determine how far away they are. Structure light 3D laser scanner (e.g 66% of new Volvo's). The front grille houses a miniature laser projector that projects a laser beam onto objects ahead to determine their shape, size and position in relation to the car. This allows accurate calculations for AEB, ACC, etc.
No, it's not usually possible to use AEB while driving your new car on cruise control.
The blind spot sensor uses radar technology to monitor the sides of the vehicle for vehicles in the driver's blind spot that might be difficult to see from inside the car/driver's seat. The technology in the system will alert the driver with a light and a sound when vehicles enter enters a blind spot zone and by applying brief braking force if necessary if needed. Braking force is applied through the electric power steering (EPS) system which allows small amounts of electronic braking force adjustment while avoiding high forces on the steering rack or wheels that would cause excessive wear or damage.
The short answer is that it's incredibly expensive to put AEB on modern cars. The cost of the equipment increases significantly as more functions are added, meaning cost-cutting measures have to be taken such as not installing multiple sensors around a car or not allowing for a full 360° sensor field of view. It's all about offering features at a reasonable price and considering the variety of customers there are who buy cars with these technologies installed, some customers could find certain limits frustrating if they couldn't activate what they wanted to use. For example, AEB can be useful when driving into busy city centres where people tend to drive close together and there is a high collision/crash risk. Therefore even though the system only has a narrow sensor range from behind the car, it could still detect potential collisions with other vehicles ahead before the driver is even aware. By detecting a potential collision, it will be helping reduce the number of accidents, helping save lives and increase city safety.
No, most AEB systems will not apply the brakes automatically for you if you're distracted or preoccupied with something else because it relies on sensors around the vehicle to detect external objects and determine whether there's a risk of a collision/crash or not. In order to brake, the system requires an active driver to brake and prevent collisions. Additionally, drivers must be ready to react at any given moment in the case of a potential collision/crash, just like automatic braking would require that no one touches the pedals until it has come to a complete stop. If your foot were on the accelerator pedal or brake pedal for example. While AEB systems are helpful, they still need drivers to pay attention in order to cut accident risk down and avoid collisions as much as possible. It's important to note that AEB should not be the only car safety feature you rely on for car safety when driving. Other safety features you should make use of include:
Seat belts.
Other pedestrian and cyclist detection systems that your car may have.
Make sure to wear your seat belt at all times and ensure passengers are wearing theirs, and drive at legal speeds. If you're driving in a populated area, keep your car's speed lower, and make sure you're ready to use your brakes if needed. Also, if your car is fitted with cameras, make sure to keep an eye on them for anything that may cause an impending crash or collision. It is increasingly common for drivers to trust the safety systems in their cars so much that they forget to stay engaged. While safety systems are undoubtedly effective at reducing the number of people harmed from a vehicular collision, and other systems like light detection and electronic stability control systems and the EyeSight system have helped, they will not be effective if the driver fails to pay attention. Systems work only because drivers are careful about the road ahead of them and the speeds they are driving at. Remember to be aware of your car's brakes at all times, and be ready to stop at a moment's notice in case you need to avoid a collision. When buying a car, make sure to check that everything, including the cameras, brakes, and AEB fitted systems work. When looking at the AEB system, check to see if it has been verified by Thatcham Research and Euro NCAP. Euro NCAP and Thatcham Research are two of the most trusted names in vehicular safety.