MODAL COUPLING CONTROLLER DESIGN USING NORMAL FORM METHOD, PART II: CONTROL

Abstract In part I [6] of this work the application ofModalCouplingControl (MCC) to vibration control of oscillatory systems from a theoretical and computer simulation perspective was studied. A second order auxiliary system as the controller which was coupled to the plant through non-linear terms was developed. The general form of the coupling terms was derived, which showed that when the system is in resonance, a strong energy link between the plant and controller is established. A phenomenon called theneckresulting from the proposed method was also introduced. In this part the neck phenomenon is studied in detail and shows that by using the proposed MCC, the neck exists for any non-linear second order system with oscillatory linear part. The stability of the closed loop system is also addressed and a relation for the selection of the controller gains for having a stable system is derived. Upon calculating the neck time analytically, an algorithm for control implementation is elaborated. Finally, the proposed controller is applied to an experimental cantilever flexible beam with piezo-ceramic actuators. The results show that the proposed controller is more effective than the conventional velocity feedback control specially when the control effort is unidirectional. This is particularly important for actuators which are not able to provide a bi-directional force such as cable-driven and shape memory alloy actuators.