Multi Positive Feedback vibration attenuation in distributed parameter resonant structures

Multi Positive Feedback (MPF) control is proposed in this paper for simultaneous resonant vibration displacement and velocity suppression in flexible distributed parameter structures. Two separate sets of control patches are used in the MPF control design, as one set is fed by vibration displacement and the other by vibration velocity. The aggregate applied control output using this approach is non-zero, due to the phase difference between displacement and velocity feedbacks. As a result, more effective suppression using the available control patches is achieved. Two norm minimization approaches are used to optimize the controller gains, and the controller is verified through numerical and experimental investigations. The results demonstrate the advantages of the MPF controller to the prior method, i.e., Modified Positive Position Feedback (MPPF), as the vibration amplitude is reduced to a much lower level. The MPF controller in simultaneous multimode suppression provides a high level of suppression for both vibration displacement and velocity at the same time. Average suppression by 80% of the uncontrolled amplitude is achievable using this method for both vibration displacement and velocity.