Vibration Control of a Seat Suspension System Using Magnetorheological Damper

Seat suspension system is critical to the ride comfort experience of a vehicle’s driver and passengers. The use of a magnetorheological (MR) damper in a seat suspension system has been shown to offer significant benefits in this regard. Most research on seat MR dampers has applied active control strategies to command the MR damper, which is an inherently semi-active device. This paper introduces a more suitable semi-active control strategy for an MR damper used in a seat suspension, enabling more effective control. The proposed control system comprises a system controller that computes the desired damping force using a sliding mode control algorithm, and a neural-based damper controller that provides a direct estimation of the command voltage that is required to track the desired damping force. The seat suspension system is approximated by base-excited single degree of freedom system. The proposed semi-active seat suspension is compared to a passive seat suspension for prescribed base displacements. These inputs are representative of the vibration of the sprung mass of a passive or semi-active quarter-vehicle suspension under bump or random-profile road disturbance. Control performance criteria such as seat travel distance and seat acceleration are evaluated in time and frequency domains, in order to quantify the effectiveness of proposed semi-active control system. The simulated results reveal that the use of semi-active control in the seat suspension provides a significant improvement in ride comfort.