研究滑动去趋势波动分析(Moving Detrended Fluctuation Analysis,MDFA)方法,得到信号时间序列的标度指数。在信号的突变点处,标度指数大幅度的波动,而在无故障处,标度指数只是在一个小范围内上下波动,因而MDFA方法可以检测工程信号中的突变。本文采用MDFA方法对齿轮和轴承因突变故障得到的信号进行仿真试验,分析结果证明了MDFA方法在旋转机械突变故障诊断中的有效性。
The method of Moving Detrended Fluctuation Analysis (MDFA) is studied, and the scaling exponent of the signal time sequence is obtained. It is found that the scaling exponent fluctuates greatly at the signal mutation point, while it fluctuates slightly in the trouble-free places. Thus, MDFA method can be used to detect the mutations in engineering signals. In this paper, the MDFA method is applied to the simulation of the signals due to mutation faults in gears and bearings, and the results show that the MDFA method is effective in mutations fault diagnosis of rotary machines.