Active vibration control of a flexible beam based on experimental modal analysis

The study of algorithms for active vibration control in flexible structures became an area of enormous interest, mainly due to the countless demands of an optimal performance of mechanical systems as aircraft and aerospace structures. Mode theory and linear quadratic state-feedback regulator are applied to suppress the vibration of a flexible link with piezoelectric actuators and strain gage transducer. The state-space dynamic model of the system was derived by using finite element method and experimental modal test. On the basis of the model, a Kalman state estimator is designed taking into account the uncertain disturbance and measurement noise. The disturbance and measurement noise are treated as white noise. A linear quadratic state-feedback regulator is implemented, which minimizes the quadratic performance function that trades off regulation performance and control effort. The experimental results show that the proposed controller can provide good disturbance rejection and can effectively reduce rapidly the strain of the flexible link and elastic vibration response.