ANTI-LOCK BRAKING SYSTEM

An anti-lock braking system, or ABS (from the German, Antiblockiersystem) is a safety system which prevents the wheels on a motor vehicle from locking while braking.A rotating road wheel allows the driver to maintain steering control under heavy braking by preventing a skid and allowing the wheel to continue interacting tractively with the road surface as directed by driver steering inputs. While ABS offers improved vehicle control in some circumstances, it can also present disadvantages including increased braking distance on slippery surfaces such as ice, packed snow, gravel, steel plates and bridges, or anything other than dry pavement.
ABS has also been demonstrated to create a false sense of security in drivers, who may drive more aggressively as a result.Since initial widespread use in production cars, anti-lock braking systems have evolved considerably. Recent versions not only prevent wheel lock under braking, but also electronically control the front-to-rear brake bias. This function, depending on its specific capabilities and implementation, is known as electronic brakeforce distribution (EBD), traction control system (TCS or ASR), emergency brake assist (BA, EBA or HBA), or electronic stability control (ESP, ESC or DSC).
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.A fully mechanical system saw limited automobile use in the 1960s in the Ferguson P99 racing car, the Jensen FF and the experimental all wheel drive Ford Zodiac, but saw no further use; the system proved expensive and, in automobile use, somewhat unreliable.
However, a limited form of anti-lock braking, utilizing a valve which could adjust front to rear brake force distribution when a wheel locked, was fitted to the 1964 Austin 1800.Chrysler, together with the Bendix Corporation, introduced a true computerized three-channel all-wheel antilock brake system called "Sure Brake" on the 1971 Imperial. It was available for several years thereafter, functioned as intended, and proved reliable.