AUTOMOBILE PASSENGER COMFORT ASSURED THROUGH LQG LQR ACTIVE SUSPENSION/

An analytical investigation of a half-car model including passenger dy namics, subjected to random road disturbances is performed, and the ad vantage of active over conventional passive suspension systems me exam ined. Two different performance indices for optimal controller design are proposed. The performance index is a quantification of both ride c omfort and road handling. Due to practical limitations, all the states required for the state-feedback controller are not measurable, and th us must be estimated with an observer. Stochastic inputs are applied t o simulate realistic road surface conditions, and statistical comparis ons between passive system and the two controllers, with and without s tate estimator, are carried out to gain a clearer insight into the per formance of the controllers. The simulation results demonstrate that a n optimal observer-based controller, when including passenger accelera tion in the performance index, retains both excellent ride comfort and road handling characteristics.