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This paper describes an approach of how to control the wheel slip of a vehicle using brake-by-wire actuators. The advantage of brake-by-wire actuators - such as the electro-hydraulic (EHB) and the electro-mechanical brake (EMB) - is that the caliper pressure or the clamping force, respectively, are known. It will be shown by measurement results that the wheels of a research vehicle equipped with an EHB system and the new control approach can be kept at any desired wheel slip on different surfaces, i.e. ice, snow, and dry asphalt.

In the scope of a research collaboration, Continental Teves (formerly ITT Automotive Europe) and Darmstadt University of Technology are developing control strategies for a low-cost Brake-by-Wire system, using no clamping-force or brake-torque sensor as feedback [1]. However, since there is a wide range of variation in the efficiency of the gear units used in electromechanical brakes, this becomes a demanding task. The paper first describes the assembly and operation of Continental Teves' third generation brake actuator, which is still operated using an integrated clamping force sensor [2]. It introduces the development environment of Darmstadt University of Technology, consisting of a brake test stand, a complex brake actuator model, and a simplified brake actuator model.

In the scope of a research collaboration, ITT Automotive Europe and Darmstadt University of Technology are developing control strategies for a low-cost Brake-by-Wire system. However, since there is a wide range of variation in the efficiency of the gear units used in electromechanical brakes, this becomes a demanding task. The paper first describes the assembly and operation of ITT's early generation brake actuator. It introduces a model of the electromechanical brake with its structure and subsystems as a major tool in the development process. A detailed analysis of the signals, already available from the brake and the vehicle, is discussed for their advantages and disadvantages with regard to a possible use in the controller design. Different approaches for clamping-force, peripheral-force and brake-torque sensing are compared. An integrated clamping force sensor for feedback control of prototype actuators was developed.

A new approach to cope with the disadvantages of the self energizing drum brake by means of mechatronics is described. The introduced system allows for control of the brake factor of a duplex drum brake from C*=2 to C*=6. Variations of the friction factor μ due to fading will be compensated to a certain extent using an electronically controlled mechanism adjusting the support base of the leading shoes of the brake. The required application forces are up to seven times lower compared to a disk brake at equal braking torques. Theory, design and measurements of a prototype brake with mechatronically controlled self energizing are the topics of this paper. The described research work was carried out at the Department of Automotive Engineering (fzd) of the University of Darmstadt.

A new ABS concept for small cars has been developed, which is based on a conventional solenoid valve driven ABS, but without the expensive motor pump unit. New ABS algorithms and electronically monitory of the brake pedal position, allows a high performance ABS braking without function limits on homogenous dry and wet roads and on snow. The pulsations of the brake pedal and the noise which appear during the ABS mode are reduced. By integration of the tandem master cylinder into the valve block a reduction in weight of approximately more than 50% in comparison to a state-of-the-art ABS is achievable. This integrated ABS/actuation unit is a pre-tested device

The Smart Booster is a new vacuum booster, which allows - in addition to the today's standard function remote controlled active braking without or in superposition to the driver. This active braking is proportionally controllable and extremly silent under operation. This new functionality allows a redefination of todays brake system layout by combining the Smart Booster with a standard ABS hydraulic control unit to create a new system configuration which is unique in hardware, independent of the amount of function potential requested. This solution is inexpensive and is able to cope with the brake requirements of today and those which results from new emerging systems like: traction control full range stability regulation deceleration control intelligent cruise control hill holder all other control systems which require remote brake intervention.