FARMINGTON HILLS, Mich.—As more car makers demand that their parts makers bring them innovations, not just components, the suppliers are rising to the challenge.
One of the more creative solutions comes from Robert Bosch Corp.'s Automotive Group, a unit of Germany's Robert Bosch Gmbh. The company has introduced an electrohydraulic brake system that is a major step toward electronic brake-by-wire.
The system translates the pressure of a driver's foot on the brake pedal into electrical signals that control a central hydraulic unit. For safety's sake, there is a backup hydraulic system should the electrical system fail.
The new system differs from conventional servohydraulic systems in that the electronic brake management system computes the brake forces required on the individual wheels independent of driver input. That allows better control of braking and easier integration of the braking systems with traction and control systems.
According to Bosch, the system allows for short braking times by automatically increasing the brake forces to compensate for a decreasing braking effect. The brake pedal does not pulse and is quiet.
Bosch's system is expected to be fitted on a DaimlerChrysler model in 2001. The electrohydraulic brake unit weighs less than conventional brake systems, Bosch said, requires a smaller installation space and does not need a brake booster. It also is easier to fit, and the number of variants is much reduced.
Most importantly, Bosch claims the system is more reliable than conventional brake systems.
The electrohydraulic brake system is easily networked with other vehicle systems, the company added, and therefore is a good basis for next-generation adaptive cruise control or for input from traffic navigation systems.