往复式机械非平稳信号的混沌与分形

Study of fault signals from main bearing of internal-combustion engine using chaos and fractal theories

为了研究往复式机械非平稳信号的非线性动力学特征,以内燃机主轴承的振动信号对其故障间隙的反映为例,在对主轴承受力分析的基础上,进行了模拟不同间隙的故障实验,获得了不同间隙下的振动信号,进一步应用混沌与分形方法研究了故障信号的混沌性,通过计算信号的两个混沌特征量—关联维数和Kolmogorov熵,找出了主轴承间隙与关联维数及Kolmogorov熵之间的变化关系,印证了对该类型非平稳信号进行混沌与分形研究的可行性。

In order to study the nonlinear dynamics of unsteady signals from reciprocal machines, taking the relation between vibration signals and fault clearances of a main bearing in an internal-combustion engine as an example, in addition to the mechanical analysis of the main bearing, fault experiments were carried out with varied main bearing clearances to get vibration signals, and those signals were proved to be chaos signals. The changing relation between clearances and their related dimensions and kolmogorov entropies was established by calculating their correlation dimensions and kolmogorov entropies. And the feasibility of studying this kind of non-steady signals using chaos and fractals theories was proved.