Design concept for an alternative heavy vehicle slip control brake actuator

Abstract

Heavy vehicles have sluggish pneumatic brake actuators that limit the cycling bandwidth of their antilock braking systems. In order to implement more effective braking controllers, the conventional actuation systems must be redesigned. This paper introduces a novel actuator that features high bandwidth, binary actuated valves placed directly on the brake chamber. A preliminary look at the effect of slip control bandwidth on the compromise between stopping distance and air usage is first presented. One-dimensional flow theory is then combined with simple thermodynamic arguments to describe charging and discharging of a brake chamber. The resulting equations are linearized and used to design a closed-loop pressure controller for the actuator. Finally, the performance of the valves is presented with respect to their steadystate accuracy and time delay.