An Overview of Roll Stabilizers and Systems for Their Control

Ship roll motion in waves can be characterized as a strongly non-linear and multivariable dynamic process which is more affected by disturbances, in general, than by the maximal controlling parameter. The article presents methods of roll motion compensation, the majority of which have been used on ships for many years. Although they are not capable of reducing permanently the error to zero, their potential has still not been used to the full. The operational efficiency of roll motion compensators can be improved using control systems. Research activities are in progress to check the applicability of advanced control methods making use of modern computer techniques. Some of them are mentioned in this paper.