Abstract
According to appearance of 4WS (Four Wheel Steering) systems and Active Suspension systems, control technology will bring a progress in the vehicle performance. Although Active Suspension systems mainly contribute to the vehicle attitude control at ordinary turning motions, a distribution of suspension loads much affects a vehicle maneuverability and stability at critical turning motions. In designing a vehicle maneuverability control at global regions, suspension as well as steering characteristics must be considered. Then, vehicle integrated control technology attracts attentions.
In this paper, a vehicle model which includes non-linear tyre characteristics is linearized by a non-linear variable transform and by ignoring high order non-linear factors. Then, a sufficient condition of robust stability for this non-linear perturbation is proposed. With this condition, H∞ control theory constructs a robust control law for a steering and suspension MIMO system. Furthermore, some computer simulations demonstrate integrated control effects.
