Active Control of Inverted Cantilever-Beam: Preliminary Study for Deck-House Vibration Control

Abstract

Low frequency vibration of a ships deck-house, especially that of a container ship, has been recognized as a feature which should be reduced to a tolerable level for those who live and work in the ship. Typical vibration data show that deck-house vibration is closely related to the r.p.m of the ships engine (its multiple harmonics) and also that its primary vibration mode is first bending. These considerations motivated an experiment to model the deck-house of a ship as a cantilever-beam; on top of which a control actuator is located. A simple algorithm to correlate excitation of the ships engine and the vibration of the top of an inverted beam and an appropriate control algorithm have been introduced and confirmed by experiment. The control algorithm has also been tested for the case of which the ship experiences hunting frequency(slowly varying frequency).