Misplaced Pages

Electronic brakeforce distribution: Difference between revisions

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
Browse history interactively← Previous editContent deleted Content addedVisualWikitext
Revision as of 04:51, 30 August 2017 editTony1 (talk | contribs)Autopatrolled, Extended confirmed users, Pending changes reviewers, Template editors275,901 edits Script-assisted fixes: per MOS:NUM, MOS:CAPS, MOS:LINK← Previous edit Latest revision as of 22:58, 9 May 2024 edit undoLucasBrown (talk | contribs)Extended confirmed users42,813 edits Adding local short description: "Automotive braking technology", overriding Wikidata description "automotive technology that varies brake force based on prevailing conditions"Tag: Shortdesc helper 
(27 intermediate revisions by 20 users not shown)
Line 1: Line 1:
{{Short description|Automotive braking technology}}
{{unreliable sources|date=August 2018}}
{{Use mdy dates|date=August 2017}} {{Use mdy dates|date=August 2017}}
[[File:Impianto frenante.svg|thumb|typical braking system for cars with brakeforce distribution:<br>
'''Electronic brakeforce distribution''' ('''EBD''' or '''EBFD''') or '''electronic brakeforce limitation''' ('''EBL''') is an automobile ] technology that automatically varies the amount of ] applied to each of a vehicle's wheels, based on road conditions, speed, loading, etc. Always coupled with ]s (ABS), EBD can apply more or less braking pressure to each wheel in order to maximize stopping power whilst maintaining vehicular control.<ref>{{cite web|url=http://jilmcintosh.typepad.com/jil/automotive-glossary.html |title=Jil McIntosh: Automotive Glossary |publisher=Jilmcintosh.typepad.com |date= |accessdate=2010-11-05}}</ref><ref>{{cite web|url=http://www.audi.ca/audi/ca/en2/tools/glossary/safety/electronic_brake_force_distribution.html |title=Audi Canada > Home |publisher=Audi.ca |date= |accessdate=2010-11-05 |deadurl=yes |archiveurl=https://web.archive.org/web/20090211135611/http://www.audi.ca:80/audi/ca/en2/tools/glossary/safety/electronic_brake_force_distribution.html |archivedate=February 11, 2009 |df= }}</ref> Typically, the front end carries the most weight and EBD distributes less braking pressure to the rear brakes so the rear brakes do not lock up and cause a skid.<ref>{{cite web|url=http://www.obd-codes.com/faq/ebd-explained.php |title=EBD Explained – Electronic Brakeforce Distribution |publisher=Obd-codes.com |date= |accessdate=2010-11-05}}</ref> In some systems, EBD distributes more braking pressure at the rear brakes during initial brake application before the effects of weight transfer become apparent.
FAD: Brake disc front<br>
FPD: Brake disc rear<br>
FPT: Rear brake drum<br>
CF: Brake control<br>
SF: servo brake<br>
PF: Brake Pump<br>
SLF: Brake Fluid Reservoir<br>
RF: Splitter braking<br>
FS: Parking Brake]]
'''Electronic brakeforce distribution''' ('''EBD''' or '''EBFD''') or '''electronic brakeforce limitation''' ('''EBL''') is an automobile ] technology that automatically varies the amount of ] applied to each of a vehicle's wheels, based on road conditions, speed, loading, etc, thus providing intelligent control of both ] and overall brake force. Always coupled with ]s (ABS), EBD can apply more or less braking pressure to each wheel in order to maximize stopping power whilst maintaining vehicular control.<ref>{{cite web|url=http://jilmcintosh.typepad.com/jil/automotive-glossary.html |title=Jil McIntosh: Automotive Glossary |website=Jilmcintosh.typepad.com |access-date=2010-11-05}}</ref><ref>{{cite web |url=http://www.audi.ca/audi/ca/en2/tools/glossary/safety/electronic_brake_force_distribution.html |title=Audi Canada > Home |website=Audi.ca |access-date=2010-11-05 |url-status=dead |archive-url=https://web.archive.org/web/20090211135611/http://www.audi.ca/audi/ca/en2/tools/glossary/safety/electronic_brake_force_distribution.html |archive-date=February 11, 2009 }}</ref> Typically, the front end carries more weight and EBD distributes less braking pressure to the rear brakes so the rear brakes do not lock up and cause a skid.<ref>{{cite web|url=http://www.obd-codes.com/faq/ebd-explained.php |title=EBD Explained – Electronic Brakeforce Distribution |website=Obd-codes.com |access-date=2010-11-05}}</ref> In some systems, EBD distributes more braking pressure at the rear brakes during initial brake application before the effects of ] become apparent.


==How ABS works== ==ABS==
{{main|Anti-lock braking system}}
Vehicle wheels may lock-up due to excessive wheel torque over tire–road friction forces available, caused by too much hydraulic line pressure. The ABS monitors wheel speeds and releases pressure on individual wheel brake lines, rapidly pulsing individual brakes to prevent lock-up. During heavy braking, preventing wheel lock-up helps the driver maintain steering control. Four channel ABS systems have an individual brake line for each of the four wheels, enabling different braking pressure on different road surfaces. Three channel systems are equipped with a sensor for each wheel, but control the rear brakes as a single unit<ref>Automotive Handbook, 9th edition, published in 2014 by Bosch, GMBH</ref>. For example, less braking pressure is needed to lock a wheel on ice than a wheel which is on bare asphalt. If the left wheels are on asphalt and the right wheels are on ice, during an emergency stop, ABS detects the right wheels about to lock and reduces braking force on the right front wheel. Four channel systems also reduce brake force on the right rear wheel, while a three channel system would also reduce force on both back wheels. Both systems help avoid lock-up and loss of vehicle control. Vehicle wheels may lock-up due to excessive wheel torque over tire–road friction forces available, caused by too much hydraulic line pressure. The ABS monitors wheel speeds and releases pressure on individual wheel brake lines, rapidly pulsing individual brakes to prevent lock-up. During heavy braking, preventing wheel lock-up helps the driver maintain steering control. Four channel ABS systems have an individual brake line for each of the four wheels, enabling different braking pressure on different road surfaces. Three channel systems are equipped with a sensor for each wheel, but control the rear brakes as a single unit.<ref>Automotive Handbook, 9th edition, published in 2014 by Bosch GmbH</ref> For example, less braking pressure is needed to lock a wheel on ice than a wheel that is on bare asphalt. If the left wheels are on asphalt and the right wheels are on ice, during an emergency stop, ABS detects the right wheels are about to lock and reduces braking force on the right front wheel. Four channel systems also reduce brake force on the right rear wheel, while a three channel system would also reduce force on both back wheels. Both systems help avoid lock-up and loss of vehicle control.


==How EBD works== ==EBD==
As per the technical paper published by Buschmann et al.<ref>http://papers.sae.org/920646/</ref> As per the technical paper published by Buschmann et al.,<ref>{{cite book|chapter-url=http://papers.sae.org/920646/|chapter=Electronic Brake Force Distribution Control - A Sophisticated Addition to ABS|first1=Gunther|last1=Buschmann|first2=Hans-Thomas|last2=Ebner|first3=Wieland|last3=Kuhn|title=SAE Technical Paper Series|date=February 1, 1992|volume=1|publisher=SAE International|access-date=August 16, 2018|doi=10.4271/920646}}</ref>
"The job of the EBD as a subsystem of the ABS system is to control the effective adhesion utilization by the rear wheels. The pressure of the rear wheels are approximated to the ideal brake force distribution in a partial braking operation. To do so, the conventional brake design is modified in the direction of rear axle overbraking, and the components of the ABS are used. EBD reduces the strain on the hydraulic brake force proportioning valve in the vehicle. EBD optimizes the brake design with regard to: adhesion utilization; driving stability; wear; temperature stress; and pedal force." "The job of the EBD as a subsystem of the ABS system is to control the effective adhesion utilization by the rear wheels. The pressure of the rear wheels are approximated to the ideal brake force distribution in a partial braking operation. To do so, the conventional brake design is modified in the direction of rear axle overbraking, and the components of the ABS are used. EBD reduces the strain on the hydraulic brake force proportioning valve in the vehicle. EBD optimizes the brake design with regard to: adhesion utilization; driving stability; wear; temperature stress; and pedal force."


EBD may work in conjunction with ABS<ref>http://brainonboard.ca/safety_features/active_safety_features_ebfd.php#q3</ref> and ] (ESC) to minimize yaw accelerations during turns. ESC compares the steering wheel angle to vehicle turning rate using a ]. "Yaw" is the vehicle's rotation around its vertical ] (turning left or right). If the yaw sensor detects more/less yaw than the steering wheel angle should create, the car is ] and ESC activates one of the front or rear brakes to rotate the car back onto its intended course. For example, if a car is making a left turn and begins to understeer (the car plows forward to the outside of the turn) ESC activates the left rear brake, which will help turn the car left. The sensors are so sensitive, and the actuation is so quick that the system may correct direction before the driver reacts. ABS helps prevent wheel lock-up and EBD helps apply appropriate brake force to make ESC work effectively and easily. EBD may work in conjunction with ABS<ref>{{cite web|url=http://brainonboard.ca/safety_features/active_safety_features_ebfd.php#q3|title=Electronic Brake-force Distribution, EBFD - Active safety features|website=Brainonboard.ca|access-date=August 16, 2018}}</ref> and ] (ESC) to minimize yaw accelerations during turns. ESC compares the steering wheel angle to vehicle turning rate using a ]. "Yaw" is the vehicle's rotation around its vertical ] (turning left or right). If the yaw sensor detects less(more) yaw than the steering wheel angle should create, the car is ] and ESC activates one of the front or rear brakes to rotate the car back onto its intended course. For example, if a car is making a left turn and begins to understeer (the car plows forward to the outside of the turn) ESC activates the left rear brake, which will help turn the car left. The sensors are so sensitive and the actuation is so quick that the system may correct direction before the driver reacts. ABS helps prevent wheel lock-up and EBD helps apply appropriate brake force to make ESC work effectively and easily.


==See also== ==See also==
Line 22: Line 35:


] ]
] ]
] ]

Latest revision as of 22:58, 9 May 2024

Automotive braking technology
Some of this article's listed sources may not be reliable. Please help improve this article by looking for better, more reliable sources. Unreliable citations may be challenged and removed. (August 2018) (Learn how and when to remove this message)

typical braking system for cars with brakeforce distribution:
FAD: Brake disc front
FPD: Brake disc rear
FPT: Rear brake drum
CF: Brake control
SF: servo brake
PF: Brake Pump
SLF: Brake Fluid Reservoir
RF: Splitter braking
FS: Parking Brake

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, loading, etc, thus providing intelligent control of both brake balance and overall brake force. Always coupled with anti-lock braking systems (ABS), EBD can apply more or less braking pressure to each wheel in order to maximize stopping power whilst maintaining vehicular control. Typically, the front end carries more weight and EBD distributes less braking pressure to the rear brakes so the rear brakes do not lock up and cause a skid. In some systems, EBD distributes more braking pressure at the rear brakes during initial brake application before the effects of weight transfer become apparent.

ABS

Main article: Anti-lock braking system

Vehicle wheels may lock-up due to excessive wheel torque over tire–road friction forces available, caused by too much hydraulic line pressure. The ABS monitors wheel speeds and releases pressure on individual wheel brake lines, rapidly pulsing individual brakes to prevent lock-up. During heavy braking, preventing wheel lock-up helps the driver maintain steering control. Four channel ABS systems have an individual brake line for each of the four wheels, enabling different braking pressure on different road surfaces. Three channel systems are equipped with a sensor for each wheel, but control the rear brakes as a single unit. For example, less braking pressure is needed to lock a wheel on ice than a wheel that is on bare asphalt. If the left wheels are on asphalt and the right wheels are on ice, during an emergency stop, ABS detects the right wheels are about to lock and reduces braking force on the right front wheel. Four channel systems also reduce brake force on the right rear wheel, while a three channel system would also reduce force on both back wheels. Both systems help avoid lock-up and loss of vehicle control.

EBD

As per the technical paper published by Buschmann et al., "The job of the EBD as a subsystem of the ABS system is to control the effective adhesion utilization by the rear wheels. The pressure of the rear wheels are approximated to the ideal brake force distribution in a partial braking operation. To do so, the conventional brake design is modified in the direction of rear axle overbraking, and the components of the ABS are used. EBD reduces the strain on the hydraulic brake force proportioning valve in the vehicle. EBD optimizes the brake design with regard to: adhesion utilization; driving stability; wear; temperature stress; and pedal force."

EBD may work in conjunction with ABS and electronic stability control (ESC) to minimize yaw accelerations during turns. ESC compares the steering wheel angle to vehicle turning rate using a yaw rate sensor. "Yaw" is the vehicle's rotation around its vertical center of gravity (turning left or right). If the yaw sensor detects less(more) yaw than the steering wheel angle should create, the car is understeering(oversteering) and ESC activates one of the front or rear brakes to rotate the car back onto its intended course. For example, if a car is making a left turn and begins to understeer (the car plows forward to the outside of the turn) ESC activates the left rear brake, which will help turn the car left. The sensors are so sensitive and the actuation is so quick that the system may correct direction before the driver reacts. ABS helps prevent wheel lock-up and EBD helps apply appropriate brake force to make ESC work effectively and easily.

See also

References

  1. "Jil McIntosh: Automotive Glossary". Jilmcintosh.typepad.com. Retrieved November 5, 2010.
  2. "Audi Canada > Home". Audi.ca. Archived from the original on February 11, 2009. Retrieved November 5, 2010.
  3. "EBD Explained – Electronic Brakeforce Distribution". Obd-codes.com. Retrieved November 5, 2010.
  4. Automotive Handbook, 9th edition, published in 2014 by Bosch GmbH
  5. Buschmann, Gunther; Ebner, Hans-Thomas; Kuhn, Wieland (February 1, 1992). "Electronic Brake Force Distribution Control - A Sophisticated Addition to ABS". SAE Technical Paper Series. Vol. 1. SAE International. doi:10.4271/920646. Retrieved August 16, 2018.
  6. "Electronic Brake-force Distribution, EBFD - Active safety features". Brainonboard.ca. Retrieved August 16, 2018.
Chassis control system
Part of the Automobile series
Suspension
Steering
Brakes
Roadwheels
Tires (Tyres)
Categories: