The current control problems present natural trend of increasing its complexity due to performance criteria that is becoming more sophisticated. The necessity of practicers and engineers in dealing with complex dynamic systems has motivated the design of controllers, whose structures are based on multiobjective constraints, knowledge from expert, uncertainties, nonlinearities, parameters that vary with time, time delay conditions, multivariable systems, and others. The classic and modern control theories, characterized by input-output representation and state-space representation, respectively, have contributed for proposal of several control methodologies, taking into account the complexity of the dynamic system. Nowadays, the explosion of new technologies made.
