IMPROVED VEHICLE PERFORMANCE USING COMBINED SUSPENSION AND BRAKING FORCES

This work presents a preliminary investigation into the integration of particular subsystems of an automobile's chassis. The specific focus of this research is the integration of Active Suspension components wi th Anti-Lock braking (ABS) mechanisms. The performance objective for t he integrated approach is defined as a reduction in braking distance o ver just anti-lock brakes. Several models, of varying degrees of compl exity, are presented to determine the effect of modeling accuracy on t he potential performance improvement. In the most detailed model, a fo ur degree of freedom Half Car vehicle model is developed along with mo dels for a hydraulic Active Suspension and an ABS system. For both sub systems, actuator dynamics are included. The tire-road interface is mo deled using the Magic Formula tire model. Individual controllers are d eveloped for the subsystems and a governing algorithm is constructed t o coordinate the two controllers. Simulations of the integrated contro ller and an ABS system, for each system model, demonstrate a significa nt increase in performance.