Controller design problem of discrete uncertain ship autopilot servo stochastic system

Purpose of this paper is to propose a method of gain-scheduled controller design for uncertain ship autopilot servo stochastic system. The Linear Parameter Varying (LPV) system, which is evolved from uncertainty linear system, is presented on characterizing uncertain time variations of parameters for the considered system. Moreover, the stochastic differential equation is employed to describe the stochastic behaviors of the system. Through the LPV system and the stochastic differential equation, the uncertain ship autopilot servo stochastic system can be completely described. For the system, the gain-scheduled design technique is applied in discussing the stabilization problems. Based on the Lyapunov function, the sufficient conditions are derived to analyze the stability of the system in the mean square. Then, the gain-scheduled controller design method can be proposed based on the derived conditions. Finally, the simulation results of uncertain ship autopilot servo stochastic system with designed controller are provided for demonstrating the effectiveness and usefulness of the proposed design method.