LMI-based robust control of floating tension-leg platforms with uncertainties and time-delays in offshore wind turbines via T-S fuzzy approach

This paper proposed the stabilization control of the tension leg platform (TLP), which is one of the most common types of offshore floating wind turbines. The main problem which exists in the installation of this kind of turbines is how to control and float them on water owing to the collision of turbulent waves of the sea. For this purpose, to design the controller on mentioned system, first a nonlinear function is introduced as a candidate of Lyapunov; then, it is proved if TLP system is stable using robust control in the presence of uncertainties, time delays and disturbances. Then, phase Takagi-Sugeno (T-S) model as a controller is provided for the mentioned system. In this case, using linear matrix inequalities (LMIs), the required feedback efficiency of the fuzzy controller can be obtained. Finally, by simulating in Simulink-MATLAB environment, it can be seen that not only the controller design is performed more easily, but all the state variables are asymptotically stable.