針對嚴格回授非線性不確定系統輔以觀察器之強健適應模糊控制器

OBSERVER-BASED ROBUST ADAPTIVE FUZZY CONTROLLER FOR STRICT-FEEDBACK NONLINEAR UNCERTAIN SYSTEMS

劉醇炫(Chun-Hsuan Liu)

指導教授 ： 江江盛

大同大學/電機資訊學院/電機工程學系所/碩士(2008年)

摘要

本論文針對具有不確定項之單輸入單輸出嚴格回授非線性不確定系統之追蹤控制問題，提出一套輔以觀測器之強健適應模糊滑動模式控制器的運算法則。運用李氏微分來轉換此非線性系統的動態方程式到所對應的等效系統。因為所有原來系統中的狀態是無法直接獲得的，所以本論文利用高增益觀察器來估測等效系統的狀態。進而，使用模糊邏輯系統及一些適應法則來近似未知的非線性函數以及不確定項的未知上界。藉由李亞普諾夫穩定理論，所提出的強健適應模糊滑動控制器可以達到整個閉迴路系統之漸近穩定性及良好的輸出追蹤性能。最後，本論文將舉出兩個例題及電腦模擬的結果，來證明所提出控制器方法的有效性。

關鍵字

追蹤誤差 ； 不確定性 ； 強健適應模糊控制器 ； 狀態濾波器 ； 模糊邏輯系統 ； 高增益觀察器 ； 適應法則 ； 滑動模式控制 ； 嚴格回授非線性系統 ； 李亞普諾夫穩定定理

並列摘要

An observer-based robust adaptive fuzzy sliding mode control algorithm is proposed in this thesis for the tracking control problem of a class of single-input single-output (SISO) strict-feedback nonlinear uncertain systems in the presence of uncertainties. The original nonlinear system dynamics can be transformed into an equivalent system by means of the concept of Lie derivative. Because all the states of the original nonlinear systems are not available for measurement, the high-gain observer is applied for estimating all states in the equivalent system. Moreover, fuzzy logic systems and some adaptive laws are used to approximate unknown nonlinear functions and the unknown bounds of uncertainties. Based on the Lyapunov stability theorem, the proposed robust adaptive fuzzy sliding mode controller can achieve the asymptotic stabilization and the output tracking performance of the whole closed-loop system. Finally, two examples and simulation results are illustrated to show the effectiveness of the proposed control scheme.

並列關鍵字

uncertainties ； tracking error ； strict-feedback nonlinear systems ； sliding mode control ； high-gain observer ； adaptive laws ； fuzzy logic systems ； state variable filters ； robust adaptive fuzzy controller ； Lyapunov stability theorem

參考文獻

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