Two-degree-of-freedom controller to reduce the vibration of vehicle engine-body system

This paper presents a two-degree-of-freedom (2-DOF) controller which is formed by combining a feedback controller with a feedforward controller to control the vibration of the vehicle engine-body system. The robust feedback controller is designed by /spl mu/-synthesis to attenuate the effect of the engine vibration disturbance by modeling the vehicle engine-body system as a nominal 4-DOF vibration system with parameter variations and unmodeled dynamics. Based on the filtered-x least mean square algorithm, an active vibration controller is used as a feedforward controller to improve the control performance further. Using an experimental device, which was designed to imitate the real vehicle engine-body system, some experiments have been made to demonstrate the effectiveness of the control scheme.