Evaluation of a State of the Art Hydraulic Brake System with Regard to Future Requirements

New technologies like alternative power trains and driver assistance systems have a big impact on brake system development. Most of the development work aims at the improvement of the actuation and modulation components of the brake system. The basic hydraulic network remained nearly the same over decades and still has to meet these new requirements. Previous papers have focused mainly on studying the behavior of single components, like for example the brake hose fluid consumption in detail. Other papers studied the complete system but simplified it extremely, so that some relevant effects are neglected. In this work, one focus is to study the influence of single relevant components, like the hydraulic unit and the hoses on the overall system performance. For this measurements with a complete hydraulic brake system, including a state of the art electromechanical brake booster and single component measurements for identification, are conducted. A variety of ambient temperatures, from low to high, is included in this study by using a temperature chamber for measurements. The dynamic pressure propagation through the system is studied, as it is crucial for future high dynamic brake systems. Besides that, key figures which not only focus on the dynamics but also on the efficiency of the system are introduced. As braking maneuvers are often short term and extremely dynamic processes, measurement equipment, like flow meters, can hardly be integrated without affecting the system behavior significantly. Therefore simulation models with different degrees of component detail are generated from an ideal system to the complete detailed system to get a better understanding of the relevant components and their effects on the before introduced key figures. This work could support developers to get a better understanding of the effects of certain components on the system overall performance and how to improve them to meet future requirements.Cross Reference: