Effect of disc thickness variation on anti-lock braking system

Disc thickness variation (DTV) can cause both brake pressure variation (BPV) and brake torque variation (BTV), which will affect vehicle braking performance whether it is equipped with anti-lock braking system (ABS) or not. To understand how DTV affects vehicle ABS performance, numerical investigation is conducted. In this study, a mathematical model for quarter vehicle is established, which consists of three sub-models: the quarter vehicle motion model, the transient tire model based on rigid ring tire model, and the single point-contact disc brake model. As primary study, simple on-off control logic according to wheel slip is used for ABS control. The ABS performance is numerically simulated under various tire-road interaction and different brake pressure conditions. Braking distance, wheel slip and vehicle longitudinal jerk are used for the effect analysis of DTV. The comparison results indicate that the ABS performance is greatly affected by DTV. DTV can extend braking distance, worsens wheel stability and reduces braking comfort, because it can cause larger braking pressure pulsation and tempestuous vehicle longitudinal oscillation.