Brake assist (BA or BAS) or emergency brake assist (EBA) is a term for an
automobile
A car or automobile is a motor vehicle with wheels. Most definitions of ''cars'' say that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people instead of goods.
The year 1886 is regarded ...
braking technology that increases braking pressure in an emergency. The first application was developed jointly by
Daimler-Benz
The Mercedes-Benz Group AG (previously named Daimler-Benz, DaimlerChrysler and Daimler) is a German multinational automotive corporation headquartered in Stuttgart, Baden-Württemberg, Germany. It is one of the world's leading car manufactu ...
LucasVarity
LucasVarity plc was a UK automotive parts manufacturer, created by a merger of the British Lucas Industries plc, and the North American Varity Corporation in August 1996.
History
LucasVarity traces its history back to the historic Canadian f ...
. Research conducted in 1992 at the Mercedes-Benz driving simulator in Berlin revealed that more than 90% of drivers fail to brake with enough force when faced with an emergency.
By interpreting the speed and
force
In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity (e.g. moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a ...
with which the
brake
A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction.
Backgroun ...
pedal is pushed, the system detects if the driver is trying to execute an emergency stop, and if the brake pedal is not fully applied, the system overrides and fully applies the brakes until the
anti-lock braking system
An anti-lock braking system (ABS) is a safety anti-skid braking system used on aircraft and on land vehicles, such as cars, motorcycles, trucks, and buses. ABS operates by preventing the wheels from locking up during braking, thereby maint ...
(ABS) takes over to stop the wheels locking up.
This is a lower level of automation than advanced emergency braking which is a
collision avoidance system
A collision avoidance system (CAS), also known as a pre-crash system, forward collision warning system, or collision mitigation system, is an advanced driver-assistance system designed to prevent or reduce the severity of a collision. In its ...
, which may initiate braking on its own if the onboard computer detects an imminent collision.
Overview
Many drivers are not prepared for the relatively high efforts required for maximum braking, nor are they prepared for the "buzzing" feedback through the brake pedal during ABS operation. If an emergency develops, a slow reaction and less than maximum braking input could result in insufficient time or distance to stop before an accident occurs.
EBA is designed to detect such "panic stops" and apply maximum braking effort within milliseconds. It interprets braking behaviour by assessing the rate that the brake pedal is activated.
If the system identifies an emergency, it automatically initiates full braking more quickly than any driver can move his or her foot. Emergency stopping distances can be shortened, reducing the likelihood of accidents – especially the common "nose-to-tail" incident.
An electronic system designed to recognise emergency braking operation and automatically enhance braking effort improves vehicle and occupant safety, and can reduce stopping distances by up to at
Brake Assist detects circumstances in which emergency braking is required by measuring the speed with which the brake pedal is depressed. Some systems additionally take into account the rapidity of which the accelerator pedal is released, pre-tensioning the brakes when a "panic release" of the accelerator pedal is noted. When panic braking is detected, the Brake Assist system automatically develops maximum brake boost in order to mitigate a driver's tendency to brake without enough force. In doing so, Brake Assist has been shown to reduce stopping distance by a significant margin (up to 20% in some studies).
Thus the brake assist is neither an Autonomous Emergency Braking nor a Collision Avoidance System as it relies on human input.
SL-Class
The Mercedes-Benz SL-Class (marketed as Mercedes-AMG SL since 2022) is a grand touring sports car manufactured by Mercedes-Benz since 1954. The designation ''SL'' derives from the German ''Sport-Leicht'' (English: Sport Light).
Initially, th ...
. In 1998 Mercedes-Benz became the first company to make Brake Assist standard equipment on all its models; other brands including Volvo and BMW soon followed suit.
Mercedes-Benz Brake Assist Plus (BAS Plus) was first made standard equipment on the W221 (2006 onwards) S-Class Mercedes-Benz. This system works much like the Volvo system with a warning and precharging of the brakes but will not automatically brake for the driver. The BAS Plus system has been shown to significantly reduce the incidence of rear-end collisions, and so is very significant in the development of driver aids that improve road safety.
Other systems like the Volvo CWAB (see below) are also available.
Volvo
The Volvo system Collision Warning with Auto Brake 'CWAB' uses a radar to detect when a collision is likely and will pre-charge the brakes so that when the driver uses the brakes, however lightly, full braking is applied. The system will also flash a light and make a warning sound. If the driver does not respond to the warning at the point where a collision cannot be avoided the system will apply the brakes automatically and dramatically reduce the speed of the collision.
This system is not considered by regulations as an emergency brake assist but as an advanced emergency braking because it does not rely on the driver to brake.
Toyota
In 1997
Toyota
is a Japanese multinational automotive manufacturer headquartered in Toyota City, Aichi, Japan. It was founded by Kiichiro Toyoda and incorporated on . Toyota is one of the largest automobile manufacturers in the world, producing about 10 ...
introduced brake assist across most of its worldwide passenger cars. This includes
Corolla
Corolla may refer to:
*Corolla (botany), the petals of a flower, considered as a unit
*Toyota Corolla, an automobile model name
*Corolla (headgear)
A ''corolla'' is an ancient headdress in the form of a small circlet or crown.Camry, Yaris and
Echo
In audio signal processing and acoustics, an echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the lis ...
.
Other
Volvo cars can also be equipped with the City Safety System which automatically brakes in stop start traffic. Mercedes-Benz also has a similar system called Distronic Plus.
Both the Volvo and the Mercedes-Benz radar systems are also used for the speed/distance regulated cruise control systems used by both manufacturers.
European Union
In October 2007 the European Commission announced that it wanted Brake Assist to be included on all new models sold in the EU as standard by 2009.
In the EU, that regulation applies since 24 November 2009 all new passenger car and light commercial vehicle types already had to be equipped with brake assist systems as standard. Since 24 February 2011, this has applied to all new vehicles.
United States
This brake assist regulation is not used in the United States because the United States do not use UNECE regulations. Instead, the USA plan to use the automatic emergency braking (AEB) on a voluntary basis.
Regulation
Brake assist system is regulated by UN Regulation No. 139, Uniform provisions concerning the approval of passenger cars with
regard to Brake Assist Systems, in some UNECE countries.
Many UNECE countries apply this passenger cars regulation since 2016 or 2017.
Entry into force of original version: 22/01/2017.https://www.unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/2020/ECE-TRANS-WP.29-343-Rev.28-Add.1.pdf
See also
*
Electronic brakeforce distribution
Electronic brakeforce distribution (EBD or EBFD) or electronic brakeforce limitation (EBL) is an automobile brake technology that automatically varies the amount of force applied to each of a vehicle's wheels, based on road conditions, speed, loa ...
*
Anti-lock braking
An anti-lock braking system (ABS) is a safety anti-skid braking system used on aircraft and on land vehicles, such as cars, motorcycles, trucks, and buses. ABS operates by preventing the wheels from locking up during braking, thereby maintainin ...
(ABS)
*
Electronic stability control
Electronic stability control (ESC), also referred to as electronic stability program (ESP) or dynamic stability control (DSC), is a computerized technology that improves a vehicle's stability by detecting and reducing loss of traction ( skiddi ...