結合QFT/H∞的設計方法

Abstract

本論文結合了QFT的設計觀念與H∞最佳控制的設計方法。針對具有參數變動的SISO受控系統，將系統所期望的性能規格轉換成適當的權重函數，利用H∞的計算設計內部的控制器，不再以傳統QFT的方法在尼可士圖做迴路整形，避免了煩瑣的作圖過程。在內部的控制器設計完成之後，就和原始的QFT方法一樣，只要再加上前置濾波器做適當的修正，就能讓系統的輸出響應符合規格要求。

This thesis presents a design method which combines the QFT design concept and H∞-optimal control technique. For an SISO plant with parameter variations, we choose appropriate weighting functions to reflect the system performance objectives and solve the controller inside the loop by H∞-norm optimization. This design procedure is different from the classical QFT method. There is no tedious graphical loop-shaping on the Nichols Chart. When the inner loop controller is obtained, an appropriate prefilter is designed so that the output response can satisfy the system specifications.