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Future driver assistance systems will not only monitor the current traffic situation, but actively assist the driver in emergencies. Autonomous intervention in vehicle dynamics will increasingly help keep the vehicle under control, even in difficult operating situations. A rapid and intelligent braking system is one of the foundations for advancing the next generation of driver assistance systems. Siemens VDO sees its electronic wedge brake (EWB) brake-by-wire technology as the answer to future vehicle chassis safety, weight, reliability, and space requirements. In early 2005, Siemens VDO Automotive AG acquired the innovative company eStop to enter the automotive brake market with the EWB. The EWB is a self-reinforcing electromechanical wedge brake, which operates around the point of maximum self-reinforcement, in order to minimize actuation forces to levels that can be supported by 12V vehicle electrical systems.

The eBrake is a novel self-reinforcing electromechanical wedge brake, which operates around the point of maximum self-reinforcement in order to minimise actuation forces. Beyond this point, the system would be unstable without an electronic controller. It is therefore important to demonstrate that this controller is robust to the range of parameter variations likely to be encountered in practice. The first stage of this process can be conducted on a dynamometer under laboratory conditions, to ensure that problems are addressed before proceeding to vehicle tests. This paper reports testing of the prototype brake on a such a dynamometer. The prototype brake itself is first briefly described, including the main instrumentation used during the tests. This followed by a short section detailing the capabilities of the dynamometer.

The eBrake® is a novel self-reinforcing electromechanical wedge brake[1]. Self reinforcement reduces the actuation forces, resulting in a more efficient and smaller brake, but demands more precise control than a conventional braking system. As a result, mathematical modelling and control law development plays a significant role in the development process. This paper describes the mathematical model of the brake and its validation against the prototype hardware. It is shown that there is a good correspondence between theory and practice, demonstrating both the validity of the model and its potential as a tool in future developments. Both the model and test results illustrate that the potential advantages of this design are realisable in practice.

eBrake® (1, 2) - a new “brake-by-wire” technology, was developed at the German Aerospace Centre, DLR e.V.. It is based on an electric powered controlled friction brake with high self-reinforcement capability. To avoid jamming the brake a special control technology was developed. Thus, by intelligently controlling a brake wedge, the kinetic energy of a vehicle is transformed into braking power. Furthermore an advanced design was found to deal with a broad variation of the friction coefficient. The physical effects involved lead to a significant reduction of energy consumption of the brake actuator compared to “conventional” brake-by-wire systems.