Titel

Active Car Brake System for Squeal Suppression Based on Piezohydraulic Actuation

Autoren

Waldschmidt, A.

Veranstaltung

Adaptronic Congress. Göttingen, 2007.

Abstract

Break squeal noise is very rare or does not occur at all in series vehicles. But it would be wrong to conclude that this phenomena is of no relevance for series production. In contrast, the development of new brake systems goes along with great effort to avoid squeal noise at the final product.

Since active systems are able to suppress the squealing of a non-optimised brake system, ERAS investigated the potential of this technology at customer order. For this, a completely functional active system which excites pressure fluctuations of the brake fluid has been developed and built. The signals of an acceleration sensor placed at the brake calliper are processed by a digital controller unit in a way that it becomes possible to reduce the noise to a level that is no longer noticeable.

This paper initially describes the formation process of brake squeal noise. After this, the actuator concept and the boundary conditions for the realisation of the active system are elucidated and the mode of operation for the controller will be explained. Results from a test series at the dynamometer will be presented, which prove a good performance of the active system under real conditions. It turned out, that also extreme loads like high temperatures or high brake pressures at disk brakes did not impact the system function.