In 1978, Bosch was the first supplier on the market to offer full-function antilock braking systems. In 1993, six years will have passed since Bosch delivered the first traction control system for passenger cars. In the meantime, a considerable amount of experience has been gained through ongoing development and testing. This experience enabled us to define the requirements for directional stability, optimum control strategy, maximum usage of the entire spectrum of drive torque intervention possibilities, and optimized hydraulics for automatic brake intervention.
The result is Bosch ABS/ASR5, which in now being introduced to the market. This new ABS/ASR family is designed in modules, which offers high flexibility in function and assembly. Systems are available with traction improvement, or with optimized directional stability and traction. Each version is adapted to the needs of the vehicle drive layout, and adaptable to customer requirements. Separate or attached electronic control unit are available.
The structure and function of the ABS5 and ABS/ASR5 hydraulic units are shown here. By eliminating the hydraulic pressure accumulator, using a modified self-priming pump to supply energy for brake intervention (with fluid drawn from the master cylinder), and using small solenoid valves, it was possible to produce a compact, inexpensive hydraulic unit.