A New H ∞ Robust Control for Discrete Ship Autopilot Stochastic System via Observer Feedback

This paper is to study an observer-based control problem of uncertain ship autopilot stochastic system. Different from the existing efforts, stochastic behaviors described as multiplicative noise is considered in LPV system to discuss practical application of ship autopilot system. Furthermore, an individual H ∞ control scheme is developed to attenuate worst effects of external disturbance on state and estimation error of the system. For designed criterion, a novel Lyapunov function with full elements and extended projection lemma are applied to derive Linear Matrix Inequality (LMI) which can directly apply convex optimization algorithm. Through solving the LMIs, the observer-based gain scheduled controller can be designed at a step such that the H ∞ performance and asymptotical stability of the considered system driven by the designed controller can be guaranteed. Finally, simulation results are provided to illustrate the applicability and usefulness of the proposed method.