Multivariable optimal control with adaptation mechanism in rudder/fin stabilizing system

This paper presents the design of a rudder/fin stabilizing system. The intercoupled relationships between yaw, roll and sway make it necessary to introduce a MIMO control system to obtain optimal performance. After discussion of the mathematical model of ship motion, an LQG controller based on Kalman filter is introduced to minimize the quadratic performance index. Taking into account the changing circumstances and the nonlinear characteristics of actuators, we apply adaptation mechanisms to adjust the weighting parameters and to reconstruct the optimal controller automatically. As can be seen from the numerical results, the newly designed rudder/fin stabilizing system shows much better performance over conventional ones