Sampled-Data Control of Ship Dynamic Positioning System Based on Hybrid Feedback

Aiming at the problem of robust H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> sampled-data control for a dynamic positioning ship, a state-derivative hybrid feedback control law is designed, and the system is reformulated as a neutral-type model with time-dependent delays using the input delay method. Combining Wirtinger’ integral inequality with the constructed Lyapunov-Krasovskii functional, the conservatism of the system is reduced. By using linear matrix inequalities, sufficient conditions for ensuring asymptotic stability are established, and the H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> performance of the system is established, and the method for designing the sampled-data controller is introduced. Finally, the simulation results show that the controller proposed in this study is able to stabilize the states of the ship and have a certain degree of robustness against external interference.