At Bosch, the idea of an antilock braking system goes back to long before 1978. As early as 1936, Bosch applied for a patent for a device "to prevent the brakes from locking". At that time, the Stuttgart company had already been a well-established manufacturer of brake systems for nine years.

Locking was to be prevented by getting the braking system to react as it would when operated by an experienced driver, who would reduce braking pressure if the wheels threatened to lock, and increase pressure again as soon as the wheels regained their grip: a see-saw sequence of increasing and decreasing braking pressure within the critical range where the vehicle’s wheels begin to lock and the driver runs the risk of losing control of the vehicle.

What was required was a system which would be able to match the vehicle’s speed to that of its wheels, measure deviations at lightning speed and react rapidly by reducing the braking pressure. This is where the early systems failed; they were too slow. It was only the introduction of semiconductor technology, available from the early 1960s, that created the preconditions for the necessary rapid triggering of the system.

In 1973, Bosch acquired a 50% interest in Teldix GmbH in Heidelberg. Fundamental research work on the problem had begun here as early as 1964. It was realized that while electronically controlled anti-locking systems were feasible, their development involved such immense financial investment that their use was virtually limited to aircraft and express trains. The cost of the basic electronics needed for an efficient system, however, had to be tailored to the equipment’s use in series-production vehicles, and this was done, thanks to the availability of integrated circuits from 1964 on. Only two years later, prototypes were already able to cut braking distances.

In 1970, Teldix, in collaboration with Daimler-Benz, presented the first trial vehicles equipped with the system christened "ABS 1". Series introduction was to follow as soon as possible, but the reliability of the control electronics still left much to be desired. In the case of a system intervening in the operation of the brakes, it was necessary to fulfil maximum safety requirements, and this was still some way off. With a control unit which at that time still had over 1,000 components, the number of potential sources of error was still decidedly too high.

In 1975, the two Teldix partners, Bosch and AEG, decided to make the development of ABS the sole responsibility of Bosch, which had been working on an anti-locking system since 1969. The aim was ABS 2, a system ready for series production for which the know-how of Bosch and Teldix was bundled. Bosch provided experience with digital electronic components which were low-priced, efficient and sturdy enough for use in series-manufactured vehicles. By comparison with analog electronics, these digital components considerably increased the calculating performance of the ABS control unit, permitting a drastic reduction in the number of components in the control device and guaranteeing the essential degree of operational safety. ABS was presented in November 1978. "One thing is certain!" ("Eines ist sicher!") promised one of the slogans for the new product, making a play on the double meaning of the German word "sicher": "certain" and "safe".

ABS consists of three components: a rotation-speed sensor on each wheel, the electronic control unit and the hydraulic modulator. When the brakes are applied, the speed sensors register the change in the wheel’s rotation speed. This data is passed on to the electronic control unit. If comparison of this data with the information stored in the control unit shows that a certain boundary value in wheel deceleration is being exceeded, in other words that there is a risk of the wheel locking, the control unit sends a signal to the hydraulic modulator to reduce braking pressure. The hydraulic modulator, connected to the braking system, withdraws brake fluid to reduce the braking pressure. Immediately the wheel begins to rotate faster again. When the rotation speed reaches a boundary value showing that the wheel is no longer about to lock but is already rotating too fast to ensure optimum deceleration, the control unit orders the hydraulic modulator to increase the braking pressure once more via the addition of brake fluid. A new cycle begins, repeated up to 40 times per second. The driver only notices a rattling sound and a minimum movement of the brake pedal up and down to the rhythm of the noises. The system was quickly adopted in all sectors of passenger-car production. The millionth ABS system was supplied in 1986.

In 1986, Bosch put its TCS Traction Control System onto the market. TCS prevents the wheels from spinning during acceleration. But this was by no means the end of the battle for better innovations: in 1995, Bosch presented its ESP Electronic Stability Program which can brake or accelerate each wheel separately in the case of sudden braking, steering or acceleration maneuvers. This prevents a vehicle from breaking away or skidding in virtually every situation. At present, this is the highlight of the Bosch family of driving dynamics systems. What will be the next innovative development?