故障診斷在轉子動力學中是很重要的研究課題。其中以不平衡為轉子系統中最常發生之故障。本文提出一方法，可在任意固定轉速下，以軸承處之不平衡響應即可診斷出多個不平衡之節點位置與不平衡量。此方法可適用於系統線上監控，隨時監控系統的不平衡變化發生，不需停機檢驗，很適合運用於固定轉速之旋轉機械，方便掌控系統之操作狀態。

Fault diagnosis is an important research issue in rotordynamics. Unbalance is one of the most frequent faults occurs in turbomachinery. A diagnosis method is proposed in this paper to identify both locations and amounts of multiple unbalance by using the unbalance response measured at the bearing locations under one specified rotating speed. This method is suitable for on-line monitoring the gradual changes of unbalance on rotating machines, especially those required fixedly operating speeds.