Abstract
This paper proposes a semi-active suspension control system design using H¥ robust control theory. The controller is developed by using two-degree-of freedom quarter-car model subjected to sinusoidal and single bump road disturbances. The performance of the closed loop system is shown for both frequency and time response. Simulation shows the vertical acceleration of the vehicle-body is 0.8911 m/s2(rms) for a sinusoidal road input and
1.564 m/s2(rms) for a single bump input. These responses satisfy the ride comfort specification according to ISO-2631. Simulation also shows the tire deflection is 0.002 m(rms) for a sinusoidal road input and 0.008 m(rms) for a single bump input which maintain the tire road contact force for good maneuvering, stability and handling. Moreover, the suspension deflection is 0.01 m(rms) for a sinusoidal road input and 0.008 m(rms) for a single bump input which guarantee no contact among suspension components.