Abstract
With a quarter car model and a half car model, a novel control schemes is proposed for force control in active suspension design by modifying Linear Quadratic Regulator (LQR) theory on frequency domain. The conventional LQR theory is applied to design the body and the tire position tracking ability with respect to road surface. For the LQR theory not capable of directly designing the controllers for the system transient response, the proposed controllers are sequentially modified around the resonant frequency of system transfer function to satisfy the ride comfort quality, suspension travel, and maneuver. Moreover, the switching control scheme is developed to self-adjust the linear control modes of this work for the flexible utilization of rattle space under various circumstances. Computer simulations are performed to verify the proposed control schemes.