Electric park brake

Electric park brakes (EPB) are used on passenger vehicles to hold the vehicle stationary on grades and flat roads. This was accomplished traditionally using a manual parking brake. With electric park brakes, the driver activates the holding mechanism with a button and the brake pads are then electrically applied onto the rear brakes.[1] This is accomplished by an electronic control unit (ECU) and an actuator mechanism. There are two mechanisms that are currently in production: 1. Cable puller systems and 2. Caliper integrated systems.[2] EPB systems can be considered a subset of Brake-by-wire technology.

First installed in the 2002 BMW 7 Series (E65), electric park brakes have since appeared in a number of vehicles.

Electric park brake in the center console in a Volkswagen Touran


Apart from performing the basic vehicle holding function required of park brakes, the EPB systems provide other functions like automatic release of the park brakes when the driver presses the accelerator, and re-clamping using additional force on detection of vehicle motion.[2] Further, the hill-hold function, which applies brakes to prevent roll-back when pulling away on a gradient, can also be implemented using the EPB.[3]


The implementation of the control logic for the actuators is carried out by either using a stand alone ECU[4] or by integrating it in the ECU for electronic stability control[5]


The design of the electric park brakes should be compliant with:

  • FMVSS 105[6]
  • FMVSS 135[7]
  • ECE 13H[8]


  1. http://www.volkswagenag.com/content/vwcorp/info_center/en/publications/2012/11/VIAVISION_No_09_November_2012.bin.html/binarystorageitem/file/VIAVISION_GB.pdf
  2. a b http://www.sae.org/events/bce/presentations/2009/jscheon.pdf
  3. http://www.volkswagen.co.uk/technology/parking-and-manoeuvring/electronic-parking-brake
  4.  http://www.trw.com/braking_systems/electric_park_brake
  5.  http://www.vda.de/en/publikationen/publikationen_downloads/detail.php?id=1163
  6.  http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?reg=571.105
  7.  http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?reg=571.135
  8.  http://www.unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/R13hr2e.pdf
Brake lining Brake linings are the consumable surfaces in brake systems, such as drum brakes and disc brakes used in transport vehicles. Drum shoes with linings History Brake linings were invented by Bertha Benz (the wife of Karl Benz who invented the first patented automobile) during her historic first long-distance car trip in the world in August 1888. The first asbestos brake linings were developed in 1908 by Herbert Frood. Although Frood was the first to implement the use of asbestos brake linings, the heat dissipation properties of the fibres were tested by various scientists, including well known materials chemist Dr Gwilym Price, who did most of his research and testing from Cambridge, United Kingdom and various Cambridge-funded institutes. Structure and function Brake linings are composed of a relatively soft but tough and heat-resistant material with a high coefficient of dynamic friction (and ideally an identical coefficient of static friction) typically mounted to a solid metal ...
Brake wear indicator A Brake wear indicator is used to warn the user and/or owner of a vehicle that the brake pad is in need of replacement. The main area of use for this is on motor vehicles with more than three wheels. However brake wear indicators are also useful for brake pads in industrial applications, including wind turbines and cranes. This article refers to disc brakes as an example, but the principle is the same for other types of friction brakes. Types of indicators There are different types of wear indicators for brake pads: Ocular inspection: A cut is made in the pad material to the depth where it shall be replaced. Requires manual inspection of the pads. Mechanical: A metal plate is designed to scratch the brake disk causing a noise when the pad has worn down to the desired level. Electrical: A metal body is embedded in the pad material that comes in contact with the rotor when the desired wear level is reached. This will light an indicator in the instrument cluster. Positi...
Hydraulic brake A hydraulic brake is an arrangement of braking mechanism which uses brake fluid, typically containing glycol ethers or diethylene glycol, to transfer pressure from the controlling mechanism to the braking mechanism. A schematic illustrating the major components of a hydraulic disc brake system. History Fred Duesenberg originated hydraulic brakes on his 1914 racing cars and Duesenberg was the first automotive marque to use the technology on a passenger car in 1921. This braking system could have earned him a fortune if he had patented it. In 1917 Malcolm Loughead (who later changed the spelling of his name to Lockheed) developed a hydraulic brake system. "Lockheed" is a common term for brake fluid in France. The technology was carried forward in automotive use and eventually led to the introduction of the self-energizing hydraulic drum brake system (Edward Bishop Boughton, London England, June 28, 1927) which is still in use today. Construction The most common arrangement ...
Air brake (road vehicle) An air brake or, more formally, a compressed air brake system, is a type of friction brake for vehicles in which compressed airpressing on a piston is used to apply the pressure to the brake pad needed to stop the vehicle. Air brakes are used in large heavy vehicles, particularly those having multiple trailers which must be linked into the brake system, such as trucks, buses, trailers, and semi-trailers, in addition to their use in railroad trains. George Westinghouse first developed air brakes for use in railway service. He patented a safer air brake on March 5, 1872. Westinghouse made numerous alterations to improve his air pressured brake invention, which led to various forms of the automatic brake. In the early 20th century, after its advantages were proven in railway use, it was adopted by manufacturers of trucks and heavy road vehicles. Truck air actuated disc brake. Design and function Air brake systems are typically used on heavy trucks and buses. The system consists...
Braking distance Braking distance refers to the distance a vehicle will travel from the point when its brakes are fully applied to when it comes to a complete stop. It is primarily affected by the original speed of the vehicle and the coefficient of friction between the tires and the road surface, and negligibly by the tires' rolling resistance and vehicle's air drag. The type of brake system in use only affects trucks and large mass vehicles, which cannot supply enough force to match the static frictional force. The braking distance is one of two principal components of the total stopping distance. The other component is the reaction distance, which is the product of the speed and the perception-reaction time of the driver/rider. A perception-reaction time of 1.5 seconds, and a coefficient of kinetic friction of 0.7 are standard for the purpose of determining a bare baseline for accident reconstruction and judicial notice; most people can stop slightly sooner under ideal conditions. Braking dist...