ESP high achiever
The most important active vehicle safety device, the Electronic Stability Program or ESP, marks 15 years of service, reports NICK DALTON.
THE system, once only available on expensive cars, is now fitted to nearly two thirds of passenger cars and sedans on the Australian market.
Earlier this month the Federal Government announced all passenger vehicles and SUVs must have the device as standard equipment by November 2011.
It was 15 years ago that MercedesBenz presented ESP, a system jointly developed with Bosch in Sweden in March, 1994. The launch vehicle was the Mercedes-Benz S 600 coupé and a few months later it appeared in the S-Class saloon ( W 140) and the SL roadster ( R 129).
But the honour of being equipped with the system in large unit numbers went to the A-Class. In response to the “moose test” during which an A-Class tipped over, it was equipped with ESP as standard from February 1998. By August 1999 it was standard on almost all Mercedes-Benz passenger cars.
ESP reduces the risk of skidding on cornering and maintains the vehicle’s directional stability even in critical conditions, for example on black ice or wet road surfaces.
It increases vehicle safety by selectively braking individual wheels, thus counteracting the tendency to skid in critical handling situations and allowing the driver to maintain control.
Oversteer is corrected by applying brake to the front outer wheel, understeer by applying brake to the rear inner wheel. ESP also can curb engine output to reduce vehicle speed.
In March 1994 two MercedesBenz test cars performed circuits on frozen Lake Hornovan. One maintained directional stability around the oval circuit, but the driver of the second car clearly had problems keeping on track.
The car’s rear end repeatedly swung out on the ice, requiring the driver to apply opposite lock and accelerate again.
These manoeuvres were closely watched from the edge of the circuit by journalists from all over the world.
They were witnessing the world premiere of a milestone in automotive technology, jointly developed by Mercedes-Benz and Robert Bosch GmbH. The test car with good directional stability was, of course, equipped with the active safety system ESP.
The anti-lock brake system (ABS) smoothed the way for ESP. ABS made its debut in 1978 in the Mercedes-Benz S-Class. Just a few years later came acceleration slip regulation (ASR, series launch 1981), an advanced development of ABS designed to control the interplay of longitudinal forces between tyres and road surface not only during braking, but for the first time also during acceleration.
Then came the automatic locking differential (ASD, 1985) and the innovative 4MATIC permanent fourwheel drive system (1985).
Lake Hornovan, Sweden, 1994: One Mercedes-Benz is fitted with ESP, the other is not.