I. Introduction
Classical control systems design for complex processes involves complex mathematical analysis and the resulting control architectures have difficulties in controlling highly nonlinear plants. To avoid these difficulties, new approaches based on neural networks for control have been proposed in the last years. The use of neural networks'learning ability makes controller design to be flexible when plant dynamics are complex and highly nonlinear. The use of dynamical neural networks for identification and control was first introduced in [1] and bridging the gap between theory and applications, as well as the relation between neural and adaptive control, have been pointed out in [2]. A systematic classification of neural networks-based control systems can be found in [3] and [4].