Robust stability control of vehicle rollover subject to actuator time delay

This paper presents a parameter-dependent robust controller design approach for active roll control of a vehicle with consideration of parameter uncertainties and actuator time delays. The objective is to improve the roll stability of the vehicle and to reduce the roll angle response during aggressive driving manoeuvres in spite of variations in vehicle parameters and the existence of actuator time delays. Sufficient conditions for stabilizing the uncertain vehicle system with input delays are derived by defining a parameter-dependent Lyapunov functional. With recourse to the random search capability of genetic algorithms (GAs), a parameter-dependent controller is found by solving a finite number of linear matrix inequalities (LMIs). Numerical simulations on a three-degree-of-freedom (3-DOF) yaw-roll vehicle model demonstrate that the designed parameter-dependent controller can improve the roll stability of the vehicle and achieve good roll control performance even when the vehicle forward speed varies in a large range and a large actuator time delay exists within allowable bounds.