Time - field analysis , frequency - field analysis and correlation function analysis in traditional , have been improved in application of fault diagnosis . and gray system , obscure subjection degree , expert system , wavelet analysis and neural network , etc . have been applied in running state of qualitative analysis system , however , it is the issue having been concerned all along in academic circle that the fault state of system is analyzed quantitatively 傳統(tǒng)的時域分析、頻域分析和相關函數(shù)分析在故障診斷應用中得到了不斷的改進,灰色關聯(lián)度、模糊隸屬度、專家系統(tǒng)、小波分析及神經(jīng)網(wǎng)絡等方法在定性分析系統(tǒng)的運動狀態(tài)中得到廣泛的應用,而定量地分析系統(tǒng)的故障狀態(tài)是學術界一直關注的問題。