Self-energizing electro-hydraulic brake
- Selbstverstärkende Elektro-Hydraulische Bremse
Liermann, Matthias; Murrenhoff, Hubertus (Thesis advisor)
Aachen : Shaker (2008)
Dissertation / PhD Thesis
In: Reihe Fluidtechnik : D
Page(s)/Article-Nr.: VII, 157 S.. : Ill., graph. Darst.
Zugl.: Aachen, Techn. Hochsch., Diss., 2008
This thesis presents research results on a new fluid-mechatronic brake principle. The Self-energizing Electro-Hydraulic Brake (SEHB) utilizes the effect of instable self-reinforcement in combination with a closed loop control. Background for the development of the brake concept is a train application. However, SEHB is not limited to any specific application. Main advantages of the concept are its minimal energy consumption, the closed loop control of the true brake torque and its feedback ability due to the decentralized low-power electronic control. This thesis introduces the new brake principle by comparing it to conventional self-reinforcing brakes. A mathematical distinction is given between self-reinforcement and self-energization on the basis of static considerations. The dynamic characteristics are analyzed using a linearized system description which is further simplified using the method of pole dominance analysis. The simplified model is used to calculate a state dependent proportional controller map on the basis of a damping criteria. Besides the theoretic analysis, the thesis presents the basic hydraulic design criteria and gives a systematic overview over different hydraulic-mechanical design solutions. A special focus is given on the valve control, since it is vital for the brake performance. Different automotive valves such as from antilock brake systems (ABS) or electronic stabilization programs (ESP) are applied using electronic power switches and current drivers. The brake test stand and two successive prototypes are outlined at the end of this thesis. Different exemplary measurement results show the performance of the implemented types of valve control and demonstrate the potential of this new brake technology.