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Many practical engineering applications require various types of fuzzy logic systems (FLSs) to design adaptive controllers for nonlinear systems with uncertainties. In this article, we will consider a fundamental theoretical question: is it possible to find a unified adaptive control design method suited to various types of FLSs? In order to solve this problem, we will introduce scalers and saturators at the input and output terminals of FLSs to form the extended FLSs (EFLS). The scalers and saturators have adjustable parameters. By designing the updated laws of these parameters and the estimate values of the fuzzy approximate accuracies, stable adaptive fuzzy controllers can be realised for a class of nonlinear systems with unknown homogeneous drift functions and gains. The proposed design method is only dependent on the outputs of EFLS and the above updated laws, thus increasing its adaptability. The fuzzy control scheme introduced in this article is suitable for all fuzzy systems with or without fuzzy rules. Simulations will also be used to show the validity of the method proposed in this article. [ABSTRACT FROM AUTHOR]

A class of similar composite systems is researched. The interconnections of systems are not symmetric and do not satisfy the matching condition. By means of the advantage of interconnections of systems, a two-step method is proposed to study the decentralized stabilization problem for the similar composite systems in this paper. First, the interconnections between subsystems are changed into a new form to satisfy the matching condition; second, based on the new form of the systems, the decentralized robust controllers are designed. In this paper, the controllers guarantee the similar composite systems quadratic stability. At last, the simulation of example is given. [ABSTRACT FROM AUTHOR]