Sampled-data fuzzy observer design of nonlinear system for wave energy converter

This paper presents a sampled-data fuzzy observer of nonlinear system for wave energy converter. The forces which affect the wave energy converter are analyzed and the dynamic equation is represented for observer design. A Takagi-Sugeno (T-S) fuzzy model is adopted for the nonlinear systems. In the T-S fuzzy model with sampled-data fuzzy observer, it obtains the norm inequality between the continuous-time state variable and the discrete-time one. Based on the norm inequality, sufficient conditions are derived for decreasing the estimation error and formulated in terms of linear matrix inequalities. Finally, a simulation is provided to verify the effectiveness of the proposed technique.