在實際的非線性系統中，常含有參數不確定性、未模式化擾動及可能受到各種外擾影響，而造成受控體的系統數學模式無法精確得知，也使得系統輸出響應不如預期。模糊理論的特色就是不需要知道系統確切的數學模式也可以籍由專家知識來控制此系統，然而，這會使我們很難去確保系統的閉迴路是穩定的，特別是當系統包含有不確定性之時。在這次的研究中，我們運用適應性模糊系統來估測不確定性的模糊參數，使得含有系統不確定性的非線性元素可以更精確的被估測和補償。為了降低外部干擾的不良影響，我們加入H∞控制器，使系統自外部輸入至控制輸出之間的閉迴路轉移函數有最小的H∞範數，以降低外擾對系統輸出之影響。
本篇論文中，在我們提出之複合控制器中，為使系統在含有不確定項之下，能加快追踨誤差的收斂速度，我們將可變結構系統(VSS)控制器加入到所提出的複合控制器中，以推導本文之適應性-模糊-H∞複合控制器設計。
最後，本文以機械手臂操作系統，作為電腦模擬之控制對象，來驗證所設計之適應性-模糊-H∞複合控制器之可行性。

In a practical nonlinear system, the actual model is hard to be described precisely by a mathematic model because of the presence of plant parameter variation, unmodeled dynamics and various disturbances appeared in the system. One of the advantages of using fuzzy control law is that it can control the system by using the rules of data obtained from expert’s knowledge without knowing exact model. However, this cause us difficult to predict the system closed-loop stability, especially for the system containing uncertainties. In this research, the adaptive-fuzzy scheme is used to estimate the uncertain fuzzy parameters so that the nonlinear elements containing plant uncertainties can more precisely be estimated and compensated in the proposed controller. To reduce the ill-effect of external disturbances, the H∞-control law is added to the proposed controller to squeeze the H∞norm of the closed-loop transfer function between the exogenous inputs and the controlled outputs.

In this paper, the adaptive-fuzzy-H∞ composite controller is then proposed. Moreover, to speed up the convergence of tracking errors under plant uncertainties, the variable structure control law is joined to the proposed controller to form the proposed adaptive-fuzzy-H∞ composite control design.

Finally, a robot manipulator is applied as an example to attest the feasibility of the proposed control methodology.

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