A robust fuzzy model following observer-based control design for nonlinear system

A robust fuzzy model following controller is designed for the nonlinear system. First, the Takagi and Sugeno fuzzy model is employed to approximate a nonlinear system. Second, based on robust fuzzy model following controller, the nonlinear system output is controlled to follow the desire output produced by a reference model. Finally, based on a Takagi and Sugeno fuzzy model, a robust fuzzy model following controller is developed to stabilize the nonlinear system, and at the same time the tracking performance is attenuated to a prescribed level. Thus, robust tracking performance is achieved in the nonlinear system. In the proposed fuzzy tracking control method, the Takagi and Sugeno fuzzy model provides a model to approximate the nonlinear system, while the H_∞ scheme provides precise control to achieve the prescribed robust tracking performance. Linear matrix inequality (LMI) techniques are employed to solve this robust fuzzy tracking control problem in nonlinear system. In the case that state variables are unavailable, a fuzzy observer-based robust fuzzy model following control is also proposed to achieve a robust tracking design for the nonlinear system. A simulation example is given to illustrate the performance of the proposed tracking design method.