This paper presents the vehicle test investigations into the application called dither control for suppression of automobile disc brake squeal and creep noise. In this study, dithering is a concept of active control introducing high-frequency control effects into a system to disturb a lower-frequency resonance. A specially designed brake system is built and the dither control is applied by a piezoelectric stack actuator in the piston of a brake caliper for vehicle application. Also, the piezoelectric drive circuit is composed of an open loop control system and a vehicle power supply and an audio amplifier system are used for driving the piezoelectric module. This study experimentally verified the noise reduction effect by applying dither control under continuous and actual braking conditions. As a result of the vehicle test, the squeal noise decreased by 30dBA on average, the squeal occurrence was reduced by 90%, and creep noise was reduced by 3 ~ 4dBA.
JaeKeun Hwang, Hyundai Motor Company , South Korea; Jeongkyu Kim, , GyuHae Park, Chonnam University, South Korea