Robust control theory applied to ship maneuvering

Robust control theory is applied to a ship control problem with plant uncertainties caused by ship speed changes and with disturbances by wind-generated waves. Velocity gain scheduling is used to formulate uncertainties for the parameter variations of a ship model. Disturbance rejection as well as rudder-servo saturation limit is also considered in the performance requirements. In the illustrative ship control problem, /spl mu/-Synthesis robust controller provides much better robust stability and performance than conventional classical controllers.