This paper presents a method of controlling the bending and torsional vibration mode of a flexible structure using H-infinity optimal control. A new idea is proposed in order to reduce the unmodeled system uncertainties by placing actuators in the nodes of certain neglected vibration modes. Then, the controller is designed based on the reduced order model and is capable of attenuating vibration without causing spillover instability. For this purpose, a three degree of freedom lumped parameter mass model of a plate structure is considered to control its vibrations using a dynamic output feedback controller. The actuator dynamics and the placement of the actuators are considered for a effective controller design method. The efficacy of the controller is shown through simulations.
H-infinity controller design for active magnetic bearings considering nonlinear vibrational rotordynamics
