強健控制器設計於動態不平衡之渦輪分子真空泵浦

Abstract

本論文旨在建構主動式磁浮軸承（AMB）運行過程中動態不平衡之時變模型，並以可適應多種需求的強健數位控制器取代類比控制器。同時，實驗整合了AMB 系統與電腦連接的數位信號處理器（DSP），可進行即時監測，以確保最佳響應與安全性。 為了使轉子在高速運轉時保持穩定，建立一個含帶質量偏心的模型至關重要。由於渦輪分子幫浦的運行環境極為嚴苛，持續監測以降低成本維護對於預防嚴重故障至關重要。從類比控制轉換為數控制帶來許多優勢，例如提升適用性、降低成本以及實現多功能人機介面操作。然而，數位控制器的實現也面臨挑戰，尤其需要精準的系統建模，以減少計算延遲對系統穩定性的影響。 本論文著重於系統識別與強健控制，以開發適用於磁浮軸承的高效數位控制系統。首先，透過前級控制器對本質上不穩定的系統進行初步穩定控制，以此為基礎進行閉迴路系統識別，從以建立準確反映 AMB 動態特性的模型。此識別模型隨後整合至控制架構，以加深對受控系統的理解。 在建立精確模型的基礎上，設計進階強健控制器，以應對系統的高度非線性、時變特性與時間延遲的影響，並確保在各種運行條件下滿足穩定性需求。改進後的數位控制器將在估算模型的模擬環境中進行驗證，為未來實際應用提供高效能與高可靠度的保證。本研究展現了數位控制相較於類比控制的顯著優勢，特別是在提升生產效能、降低成本與增強適用性方面。

This thesis aims to construct a time-variant model for dynamic unbalance in active magnetic bearings (AMBs) during operation, replacing the analog controller with a robust digital controller adaptable to diverse requirements. Integrated with a digital signal processor (DSP) connected to a computer, the AMB system can be monitored in real time to ensure optimal performance and safety.

To stabilize the rotor during high-speed operation, a feasible model focusing on eccentricity is essential. Given the pump a severe operating circumstance, continuous monitoring and straightforward maintenance are crucial to prevent fatal failures. Transitioning from analog to digital control introduces benefits such as enhanced applicability, reduced costs, and human-computer interface access. However, implementing a digital controller also presents challenges, particularly the need for precise system modeling to mitigate calculation delays that could affect stability.

This thesis emphasizes system identification and robust control for developing an effective digital control system for magnetic bearings. Initial stabilization of the inherently unstable system is achieved using a primary controller, after which system identification can proceed to construct an accurate model that reflects the dynamic characteristics of AMBs. This identified model is then integrated into the control framework to enhance the understanding of the plant.

With a refined model established, a robust controller is designed to manage the highly nonlinear and time-varying dynamics of the system and effects of time delay, meeting specified stability requirements across various conditions. The improved digital controller is implemented in the simulation of the estimation model, ensuring high performance and reliability in practical implementation in the future. This approach showcases the substantial advantages of digital control over analog, particularly in improving production, cost, and applicability.