H-infinity Strongly Stabilizing Bandpass Controllers for Selective Natural Modes Damping in Flexible Structures

In this paper by extending previous work of one of the authors the design of a MIMO H∞ feedback controller for flexible systems is proposed. The controller has some very desirable properties for applications related to noise and vibration reduction, since it has limited bandwidth, zero dc-gain and can selectively increase the damping of only some selected natural modes of the flexible structure. This characteristic turns out to be very useful when dealing with lightly damped structures forced by broadband disturbances. Since however the controller is not necessarily stable, by solving an LMI problem, a stable version of the controller is also obtained. The effectiveness of the proposed control strategies is shown on a detailed COMSOL FEM model