Manoeuvring Control of a Modern Warship

The conventional approach to ship steering and roll stabilisation is to treat the control loops as two separate design problems ignoring any cross-coupling between them. This approach has proved satisfactory for conventional vessels where the amount of inter-action is normally slight. However, in the case of highly manoeuvrable warships the inter-action is pronounced because of their large control surfaces, high speed and low tonnage. Consequently, an integrated control scheme, based on the multivariable approach, would seem to be suited to this control problem. In this paper the application of multivariable techniuqes for the control of ship motion is investigated. Simulation studies on the implementation of a multivariable controller to suppress the highly inter-active and nonlinear roll/yaw dynamics of a modern naval warship are described. The results presented are used to demonstrate the operational advantages of an integrated steering/stabilisation control scheme.