Electronic stability control

Electronic stability control (ESC), also referred to as electronic stability program (ESP) or dynamic stability control (DSC), is a computerized technology that improves a vehicle's stability by detecting and reducing loss of traction (skidding). When ESC detects loss of steering control, it automatically applies the brakes to help 'steer' the vehicle where the driver intends to go. Braking is automatically applied to wheels individually, such as the outer front wheel to counter oversteer, or the inner rear wheel to counter understeer. Some ESC systems also reduce engine power until control is regained. ESC does not improve a vehicle's cornering performance; instead, it helps to minimize the loss of control. Electronic stability control (ESC), also referred to as electronic stability program (ESP) or dynamic stability control (DSC), is a computerized technology that improves a vehicle's stability by detecting and reducing loss of traction (skidding). When ESC detects loss of steering control, it automatically applies the brakes to help 'steer' the vehicle where the driver intends to go. Braking is automatically applied to wheels individually, such as the outer front wheel to counter oversteer, or the inner rear wheel to counter understeer. Some ESC systems also reduce engine power until control is regained. ESC does not improve a vehicle's cornering performance; instead, it helps to minimize the loss of control. According to the U.S. National Highway Traffic Safety Administration and the Insurance Institute for Highway Safety in 2004 and 2006 respectively, one-third of fatal accidents could be prevented by the use of the technology. ESC has been mandatory in new cars in Canada, the USA, and the European Union since 2011, 2012, and 2014, respectively. In 1983, a four-wheel electronic 'Anti-Skid Control' system was introduced on the Toyota Crown. In 1987, Mercedes-Benz, BMW and Toyota introduced their first traction control systems. Traction control works by applying individual wheel braking and throttle to maintain traction under acceleration, but unlike ESC, it is not designed to aid in steering. In 1990, Mitsubishi released the Diamante in Japan. It featured a new electronically controlled active trace & traction control system. Named TCL when it first entered the market, the system evolved into Mitsubishi's modern Active Skid and Traction Control (ASTC) system. Developed to help the driver maintain the intended line through a corner; an onboard computer monitored several vehicle operating parameters through various sensors. When too much throttle had been used when taking a curve, engine output and braking were automatically regulated to ensure the proper line through a curve and to provide the proper amount of traction under various road surface conditions. While conventional traction control systems at the time featured only a slip control function, Mitsubishi's TCL system had an active safety function, which improved course tracing performance by automatically adjusting the traction force (called 'trace control'), thereby restraining the development of excessive lateral acceleration while turning. Although not a ‘proper’ modern stability control system, trace control monitors steering angle, throttle position and individual wheel speeds, although there is no yaw input. The TCL system's standard wheel slip control function enabled better traction on slippery surfaces or during cornering. In addition to the system's individual effect, it also worked together with the Diamante's electronically controlled suspension and four-wheel steering to improve total handling and performance. BMW, working with Bosch and Continental, developed a system to reduce engine torque to prevent loss of control and applied it to most of the BMW model line for 1992, excluding the E30 and E36. This system could be ordered with the winter package, which came with a limited-slip differential, heated seats, and heated mirrors. From 1987 to 1992, Mercedes-Benz and Bosch co-developed a system called Elektronisches Stabilitätsprogramm ('Electronic Stability Program', trademarked as ESP) to control lateral slippage. In 1995, three automobile manufacturers introduced ESC systems. Mercedes-Benz, supplied by Bosch, was the first to implement ESP with their Mercedes-Benz S 600 Coupé. Toyota's Vehicle Stability Control (VSC) system appeared on the Toyota Crown Majesta in 1995. General Motors worked with Delphi Automotive and introduced its version of ESC, called 'StabiliTrak', in 1996 for the 1997 model year on select Cadillac models. StabiliTrak was made standard equipment on all GM SUVs and vans sold in the U.S. and Canada by 2007, except for certain commercial and fleet vehicles. While the StabiliTrak name is used on most General Motors vehicles for the U.S. market, 'Electronic Stability Control' is used for GM's overseas brands, such as Opel, Holden and Saab, except in the cases of Saab's 9-7X and 9-4X (which also use the StabiliTrak name). The same year, Cadillac introduced an integrated vehicle handling and software control system called the Integrated Chassis Control System (ICCS), on the Cadillac Eldorado. It involves an omnibus computer integration of engine, traction control, Stabilitrak electronic stability control, steering, and adaptive continuously variable road sensing suspension (CVRSS), with the intent of improving responsiveness to driver input, performance, and overall safety, similar to Toyota/Lexus Vehicle Dynamics Integrated Management. In 1997, Audi introduced the first series production ESP for all-wheel drive vehicles (Audi A8 and Audi A6 with quattro (four-wheel drive system)). In 1998, Volvo Cars began to offer their version of ESC called Dynamic Stability and Traction Control (DSTC) on the new Volvo S80. Meanwhile, others investigated and developed their own systems.