ROBUST CONTROL DESIGN BY QFT METHODOLOGY FOR A DYNAM POSITIONING PROBLEM OF A MOORED FLOATING PLATFORM

Abstract: An analysis and design of a dynamic positioning system for a moored floating platform has been carried out. The model of the platform is a single degree of freedom SIMO system. The goal is to minimize the drift resulting from the wave action by appropriate thrusters control. An interesting question is that the plant has less degree of freedom for actuation and is more difficult to control. The multivariable QFT robust control technique for underactuated systems is employed. The problem is solved by an iterative multi-stage sequential procedure. It is shown that the control achieves the positioning system