Modeling, Experimentation and Simulation of a Brake Apply System

This study presents the development and validation of an analytical dynamic model of the brake apply system of a vehicle. The brake apply system includes the models for brake pedal, vacuum booster, master cylinder, and proportioning valves; the interactions with the wheel brake system, which comprises the front and rear foundation brakes, are included by modeling their compliances. Laboratory experiments are performed on a bench setup of the brake system and the experimental data is compared with the simulation results. The model is formulated such that the inputs are the pedal force applied by the driver, the vacuum supplied by the engine and the physical parameters of the brake components. Preliminary analysis shows that the simulation tracks the data quite closely throughout the regime of operation. Sensitivity studies are performed to show the effect of different friction parameters on the system performance.