Robust Control of Electro Rheological Suspension System Based on LMIApproach

This paper presents a robust-H∞ control design for semi-active vehicle suspension system using linear matrix inequality (LMI). In vehicle control systems, the ability of damping vibrations is very important against the external and internal disturbances. Generally, it is impossible to eliminate all of this disturbances. So, it is essential to use the robust control. In this study, the state feedback H∞ control for a semi-active quarter car suspension using an Electro-Rheological damper with spring and damper has been utilized. The dynamic system of the suspension systems is first formed in terms of the control objectives, i.e., ride comfort, road holding, suspension deflection, and maximum actuator control force. Furthermore, using Lyapanov theory and linear matrix inequality (LMI) approach, the existence of admissible controllers is formulated in terms of LMIs. Finally, a quarter-car vehicle model is exploited to demonstrate the effectiveness of the proposed method. A comparison of the results between the semi-active and passive suspension systems shows that the attenuation of the disturbance against the bump and stochastic input is obtained.