Vibration Control of an ER Seat Suspension for a Commercial Vehicle

This paper presents a semi-active seat suspension with an electrorheological (ER) fluid damper. A cylindrical ER seat damper is devised on the basis of a Bingham model of an arabic gum-based ER fluid and its field-dependent damping characteristics are empirically evaluated. A semi-active seat suspension is then constructed, and the governing equations of motion are derived by treating the driver mass as a parameter uncertainty. A sliding mode controller, which has inherent robustness to system uncertainties, is formulated to attenuate seat vibration due to external excitations. The controller is then experimentally realized, and controlled responses are presented in both time and frequency domains. In addition, a full-car model consisting of primary, cabin, and seat suspensions is established, and a hardware-in-the-loop simulation is undertaken to demonstrate a practical feasibility of the proposed seat suspension system showing ride comfort quality under various road conditions.