الموضوع: موضوع مهم اوي بالنسبة للسيارات الجديدة .... و عايز رأيكم

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An anti-lock braking system (ABS) (translated from German, Anti-Blockier System) is a safety system on motor vehicles which prevents the wheels from locking while braking
A rotating road wheel allows the driver to maintain steering control under heavy braking, by preventing a locked wheel or skid, and allowing the wheel to continue to forward roll and create lateral control, as directed by driver steering inputs. Disadvantages of the system include increased braking distances under some limited circumstances (ice, snow, gravel, "soft" surfaces), and the creation of a "false sense of security" among drivers who do not understand the operation, and limitations of ABS
Since it came into widespread use in production cars (with "version 2" in 1978), ABS has made considerable progress. Recent versions not only handle the ABS function itself (i.e. preventing wheel locking under braking), but also electronic control of the front-to-rear bias known as electronic brakeforce distribution (EBD), traction control system (TCS or ASR), an "emergency" brake assist (BA, EBA or HBA), and electronic stability control (ESP, ESC or DSC), amongst others.

Anti-lock braking systems were first developed for aircraft in 1929, by the French automobile and aircraft pioneer, Gabriel Voisin, as threshold braking an airplane is nearly impossible. An early system was Dunlop's Maxaret system, introduced in the 1950s and still in use on some aircraft models.

Operation
The anti-lock brake controller is also known as the CAB (Controller Anti-lock Brake).

A typical ABS is composed of a central electronic control unit (ECU), four wheel speed sensors (one for each wheel), and two or more hydraulic valves within the vehicle brake circuit. The ECU constantly monitors the rotational speed of each wheel. When it senses that any number of wheels are rotating considerably slower than the others (a condition that is likely to bring it to lock - see note below), it actuates the valves to decrease the pressure on the specific braking circuit for the individual wheel, effectively reducing the braking force on that wheel. The wheel(s) then turn faster; when they turn too fast, the force is reapplied. This process is repeated continuously, and this causes the characteristic pulsing feel through the brake pedal. A typical anti-lock system can apply and release braking pressure up to 20 times a second.

Note: The ECU needs to determine when some of the wheels turn considerably slower than any of the others because when the car is turning the two wheels towards the center of the curve inherently move slightly slower than the other two – which is the reason why a differential is used in virtually all commercial cars.
The sensors can become contaminated with metallic dust, or other contaminants, and fail to correctly detect wheel slip; this is not always picked up by the internal ABS controller diagnostic.[citation needed] In this occurrence, the ABS warning light will usually be illuminated on the instrument panel, and the ABS will be disabled until the fault is rectified.
Additional developments
Modern Electronic Stability Control (ESC or ESP) systems are an evolution of the ABS concept. Here, a minimum of two additional sensors are added to help the system work: these are a steering wheel angle sensor, and a gyroscopic sensor. The theory of operation is simple: when the gyroscopic sensor detects that the direction taken by the car does not coincide with what the steering wheel sensor reports, the ESC software will brake the necessary individual wheel(s) (up to three with the most sophisticated systems), so that the vehicle goes the way the driver intends. The steering wheel sensor also helps in the operation of Cornering Brake Control (CBC), since this will tell the ABS that wheels on the inside of the curve should brake more than wheels on the outside, and by how much.

Traction control system
The ABS equipment may also be used to implement traction control system (TCS, ASR) on acceleration of the vehicle. If, when accelerating, the tire loses traction, the ABS controller can detect the situation and take suitable action so that traction is regained. Manufacturers often offer this as a separately priced option even though the infrastructure is largely shared with ABS. More sophisticated versions of this can also control throttle levels and brakes simultaneously.

Effectiveness
A 2003 Australian study[3] by Monash University Accident Research Centre found that ABS:

Reduced the risk of multiple vehicle crashes by 18 percent,
Reduced the risk of run-off-road crashes by 35 percent.
On high-traction surfaces such as bitumen, or
concrete, many (though not all) ABS-equipped cars are able to attain braking distances better (i.e. shorter) than those that would be easily possible without the benefit of ABS. In real world conditions even an alert, skilled driver without ABS would find it difficult, even through the use of techniques like threshold braking, to match or improve on the performance of a typical driver with a modern ABS-equipped vehicle. ABS reduces chances of crashing, and/or the severity of impact. The recommended technique for non-expert drivers in an ABS-equipped car, in a typical full-braking emergency, is to press the brake pedal as firmly as possible and, where appropriate, to steer around obstructions. In such situations, ABS will significantly reduce the chances of a skid and subsequent loss of control.

In gravel, sand and deep snow, ABS tends to increase braking distances. On these surfaces, locked wheels dig in and stop the vehicle more quickly. ABS prevents this from occurring. Some ABS calibrations reduce this problem by slowing the cycling time, thus letting the wheels repeatedly briefly lock and unlock. The primary benefit of ABS on such surfaces is to increase the ability of the driver to maintain control of the car rather than go into a skid — though loss of control remains more likely on soft surfaces like gravel or slippery surfaces like snow or ice. On a very slippery surface such as sheet ice or gravel, it is possible to lock multiple wheels at once, and this can defeat ABS (which relies on comparing all four wheels, and detecting individual wheels skidding). Availability of ABS relieves most drivers from learning threshold braking.

ABS works with your regular braking system by automatically pumping them. In vehicles not equipped with ABS, the driver has to manually pump the brakes to prevent wheel lockup. In vehicles equipped with ABS, your foot should remain firmly planted on the brake pedal, while ABS pumps the brakes for you so you can concentrate on steering to safety.

When activated, some earlier ABS systems caused the brake pedal to pulse noticeably. As most drivers rarely or never brake hard enough to cause brake lock-up, and a significant number rarely bother to read the car's manual, this may not be discovered until an emergency. When drivers do encounter an emergency that causes them to brake hard, and thus encounter this pulsing for the first time, many are believed to reduce pedal pressure, and thus lengthen braking distances, contributing to a higher level of accidents than the superior emergency stopping capabilities of ABS would otherwise promise. Some manufacturers have therefore implemented a brake assist system that determines that the driver is attempting a "panic stop" and the system automatically increases braking force where not enough pressure is applied. Nevertheless, ABS significantly improves safety and control for drivers in most on-road situations.

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ممكن بس لو فى عربيه فيها absوازيد 5 الالف اجيبها

مازال كل الردود فيها وجهات نظر مختلفة في الموضوع و لكن انا شايف ان في اعضاء كتير محترمين بيفضلوا استغلال التكنولوجيا او عنصر التطور في السيارة بدل هذا التطور متاح و له ميزه فعاله في السيارة نفسها
و لكن القول الفصل بين الاعضاء ان اختلاف الاراء لا يفسد للود قضية
و شاكر جداً الي كل من ساهم في هذا الموضوع بوجه نظره المحترمه .......