伺服馬達的H_∞/QFT整合式穩健控制器設計與實現

Abstract

本論文首先提出了H_∞/QFT穩健控制器設計方法，利用QFT控制架構給定設計規格邊界條件，再用H_∞理論取代原本的尼可士圖設計控制器，使系統達成穩健性的同時符合系統規格的要求，隨後將此方法實現在伺服馬達上，並測試在具有負載時的馬達穩健性。為了配合控制器在真實系統的可用性，本研究在設計過程中，將數值計算出的控制器重新設計，使馬達空載、負載2.4J和負載3.9J得到頻寬9.15Hz、11.40Hz、13.70Hz，之後整合DDOB和ZMETC在維持穩健性的前提下進一步提升頻寬，使馬達空載、負載2.4J和負載3.9J的頻寬分別提升到17.20Hz、25.40Hz、26.70Hz。最後比較H_∞/QFT和傳統QFT對伺服馬達的穩健性，證實H_∞/QFT不論是對輸出命令變化還是外加負載變化的抑制都有極佳的效果。

The H_∞/QFT (H-infinity/quantitative feedback theory) robust controller design method has been designed, realized, and analyzed for AC servo motors in this Thesis. By using the QFT control structure for choosing system design goals and replacing the Nichols chart by H_∞ theory, robust control design can meet specifications and robustness for control systems. To realize robust controller on the Shih-Lin AC servo motor against the variation of inertia or external loading in real applications, the numerically calculated controller needs to be re-designed with real consideration. Experimental results indicate that the velocity bandwidth of motor with no load, with 2.4J and 3.9J leads to 9.15Hz, 11.40Hz, 13.70Hz, respectively. Results also indicate that they can perform similar performance with the present robust control design. Finally, by applying DDOB (digital disturbance observer) and ZMETC (zero magnitude error tracking controller), the robustness for the servo motor is maintained well and it enhances the bandwidth of systems. The velocity bandwidth of the motor with no load, with load 2.4J and with load 3.9J can be further improved to 17.20Hz、25.40Hz、26.70Hz, respectively. Compared with the QFT controller, the H_∞/QFT controller leads to more robust performance even with additional control blocks in the new structures.