A NEW CONTROL ALLOCATION DESIGN FOR MARINE VESSEL BASED ON ROBUST CONTROL

In this study, we propose a new approach to control design problem for the marine vessels which are moored or controlled by several actuators. In sometime and special purposes, the vessels are to be positioned by actuators which are installed on them or assisted by extra systems. We can see that there are many types of actuator in the real applications. Among them, the useful and widely applicable systems are thruster and mooring winch. In the case of applying these systems to the actual plants, a complicate fact is the control allocation problem. To make a good solution on this problem, many results have been given and verified by many researchers with a two step process. Exactly it means that controller design and control allocation process are carried out individually. In the result, the stability and performance of the control system are not considered, such that the basic objectives of control system design are not guaranteed any more. In this paper, the author gives a sophisticated solution for this issue. The authors show a new design method in which the controller design and control allocation problem can be converted by one step problem. In other word, the authors show that the system stability, control performance and allocation problem are unified by a condition obtained from H  control theory.