Ride quality investigation of an electrorheological seat suspension to minimize human body vibrations

This paper presents vibration control performance of a semi-active electro-rheological (ER) seat suspension incorporating a vibration model of the human body. A cylindrical type of ER seat damper is manufactured and its field-dependent damping force is experimentally evaluated. A human body model is derived and integrated with the governing equations of an ER seat suspension, which consists of seat, spring, and ER seat damper. The seat-driver model is then reduced through a balanced model reduction in order to design a state observer from which the state of each human body segment is obtained for evaluation. A semi-active skyhook controller is then designed, and control responses (ride quality) are evaluated in both time and frequency domains through computer simulation and experimental realization. In addition, a comparison of the proposed semi-active ER seat suspension to a conventional passive seat suspension system is undertaken.