Controle por Realimentação de Saída de Sistemas Fuzzy Takagi-Sugeno Sujeitos a Restrições
Output Feedback Control of Fuzzy Takagi-Sugeno Systems Subject to Constraints
Control Under Constraints, Takagi-Sugeno, Nonlinear Systems, Fuzzy Systems, Regulation.
Dealing with constraints in controller design is one of the key challenges in modern control theory and application. In practice, most industrial systems is characterized by physical limitations in states and control action. In particular, the problem of constraining the trajectory of dynamic systems has been investigated based on the approach known as set invariance, by incorporating such constraints from a special class of invariant sets, the polyhedral ones. Another inherent feature of industrial systems, especially the most modern ones, is the high complexity associated with their respective mathematical models. Such models are constituted by nonlinearities, which makes the synthesis of the controller a difficult task. In this sense, based on fuzzy systems theory, it is possible to use a simpler equivalent model whose formulation naturally provides a mechanism for merging a set of models and linear local controllers. In this work, is proposed a control design methodology that has as its main objective the simultaneous calculation of the invariant set and of the controller for nonlinear, invariant and time discrete systems, in order to solve the constrained regulation problem, as well as the use of the Takagi-Sugeno fuzzy model. At first, the methodology was developed based on state feedback control. Some preliminary studies point out the way to go when it is considered an output feedback control law, in view of the use of a Takagi-Sugeno-type fuzzy observer. The Takagi-Sugeno fuzzy observer is given as a function of the combination of local linear observation laws, in line with the fuzzy modeling process.