使用複合式控制針對轉子的主動軸承座之DSP實現

Abstract

本報告在討論轉子普遍存在一個相同的問題，那便是都有不平衡問題的存在，在旋轉機械上不平衡是產生振動的主要因素，轉子平衡校正，在策略上有兩種方式，一是不平衡補償法(Imbalance Compensation)，另外是自動對心法(Autocentering)，在本報告我們所使用的策略是前者。首先將轉子的動態模型導出，以利於分析控制。再者利用不平衡估測與動平衡的方法，得到不平衡量而加以反方向的試重完成平衡的動作。並利用不同的控制結構與方法，結構上有前饋、回饋與複合式，方法有反覆消除法(Iterative Cancellation)、最小均方法(LMS)、線性二次高斯法(LQG)。這些控制方法我們使用在轉子測試台(Rotor Kit)中，透過DSP晶片執行控制器以實現之，使用現代的控制方法來解決傳統軸承之不平衡問題，有效的消除掉因為不平衡而產生的振動問題，並實證出上面所提及控制方法對振動控制的效果及其優缺點比較，並以效果最好的複合控制法運用轉子的不平衡振動控制，希望能在精密加工的主軸振動控制有所貢獻。

The fact that mass unbalances of a rotor cannot be completely avoided. The unbalance in the rotors of rotating machinery causes undesirable vibrations. There are two vibration control strategies, one is imbalance compensation and the other is autocentering. Our strategy in the research is the former. In order to analyze and control unbalances of rotor, we firstly show the modeling of rotor motion. Then applying the dynamic balance and influence coefficient procedure to find the correction mass. Added to the rotor to cancel unbalances. Three control algorithms and three control structures are used. The least-mean-square (LMS) with synthetic reference, the linear quadratic gaussian (LQG) control and iterative cancellation are employed for controller synthesis. Feedback, feedforward and hybrid configurations are used as the major structures. The controllers are implemented by using a digital signal processor (DSP) in the rotor kit. Using modern control methods to compensate rotor imbalance in conventional ball bearing. And these proposed methods are effective in attenuating vibrations. These control methods are compared. The experimental results indicate that hybrid structure yields the best performance in terms of attenuation and convergence speed. We wish that the hybrid active vibration control can be used in the principal axis of precision machining.