Active safety

Function

Active safety systems prevent crashes

The best protection against crashes is to prevent them. For more than 30 years Bosch has been developing active safety systems that significantly contribute to the reduction in the number of crashes, despite increasing traffic density. Active safety systems such as the Antilock Braking System (ABS), the Traction Control System (TCS) or the Electronic Stability Program (ESP®) intervene before a crash occurs.
Customer benefits
Customer benefits

Prevention of accidents

New safety functions by means of networking existing systems and components

Modular safety systems

Synergies due to expertise in system development and networking

Antilock Braking System (ABS)

Safe braking without wheel lockup

The introduction of the world’s first Antilock Braking System for passenger cars by Bosch in 1978 is a milestone in the area of active driving safety. Since then we have developed our ABS further to offer smaller, lighter and more powerful systems.

Working principle

In an emergency braking situation the braking force applied by the driver may be greater than the tire can handle: the wheel locks. The tire can now no longer transfer any lateral traction forces. The vehicle becomes unstable and uncontrollable, since the vehicle no longer reacts to the steering input of the driver. In a vehicle equipped with an Antilock Braking System, wheel-speed sensors measure the speed of rotation of the wheels and pass this information to the ABS control unit. If the ABS control unit detects that one or more wheels tend to lock, it intervenes within milliseconds by modulating the braking pressure at each individual wheel. In doing so, ABS prevents the wheels from locking and ensures safe braking: the vehicle remains steerable and stable. Generally, the stopping distance is also reduced.

Component

ABS Generation 9

Traction Control System (TCS)

Acceleration without wheel spinning

The Traction Control System (TCS) is a further development of the ABS technology and was first launched onto the market by Bosch in 1986 – at first for commercial vehicles and in 1987 for passenger cars.

The Traction Control System from Bosch prevents wheel spin when starting off or accelerating, particularly on a slippery or wet road surface. While the Antilock Braking System prevents the wheels from locking during braking by reducing the braking pressures, TCS ensures that the wheels do not spin when driving off or accelerating. To do this, the drive torque at each driven wheel is reduced correspondingly. TCS improves the traction of the vehicle and increases vehicle safety by avoiding unstable driving situations within the limits of physics.

Working principle

If one of the driven wheels tends to spin, TCS is activated. The Traction Control System reduces the drive torque supplied by the engine and, if necessary, brakes individual wheels in order to regulate the slip of the driven wheels as quickly as possible to the optimum level.

Electronic Stability Program (ESP®)

Prevents skidding

In 1995, active driving safety reached yet another dimension thanks to the introduction of ESP®. ESP® incorporates the functions of ABS and TCS, with the additional benefits of stability control. The system supports the driver in all driving situations. It detects if skidding is imminent and intervenes by applying braking power to individual wheels and/or reducing engine power in order to restore the vehicle's stability.

Component

ESP for light trucks