PUB - Hydro-Mechanical Closed-Loop Brake Torque Control for Railway Disc Brakes (EN)


A paper on “Hydro-Mechanical Closed-Loop Brake Torque Control for Railway Disc Brakes” was published at the International Railway Symposium Aachen in Aachen.


The generated braking torque of disc brakes is highly dependent on the tribological contact between brake disc and brake pads. Since the actual friction forces are subjected to various disturbances, the resulting brake effect is similarly influenced. Common countermeasures try to optimize the friction pairing to limit the deviation. Within an ongoing research project at the Institute for Fluid Power Drives and Systems (ifas) of RWTH Aachen University, a novel approach is taken. To compensate the disturbances, an innovative hydraulic disc brake with closed loop control of the braking torque is being developed. This allows a higher utilization of the physical braking potential, an improved and more reliable braking process and possibly the use of cheaper, less optimized friction pairings. In this project, the closed loop control is achieved by a hydro-mechanical control unit embedded in the supporting structure of a conventional hydraulic disc brake, using the supporting forces of the caliper as feedback variable for the control unit. Due to the hydro-mechanical implementation of the control, a highly robust and reliable control system can be realized. In the scope of this article, the dynamic brake behavior of the novel closed loop system is closely regarded and suitable models for the description are introduced. A control concept is researched and the resulting prototypes are presented.