离散振动信号分形盒维数的改进算法和应用  

Fractal Box Dimension of Discrete Vibration Signals: Improved Algorithm and Applications

作　　者：訾艳阳[1] 胥永刚[1] 何正嘉[1] 

机构地区：[1]西安交通大学,西安710049

出　　处：《机械科学与技术》2001年第3期373-375,共3页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家自然科学基金资助项目 (5 9775 0 2 3 ) ;陕西省自然科学研究计划项目 (97G14 )

摘　　要：提出了振动信号的双尺度性概念 ,分析了离散信号盒维数一般计算方法的不足 ,推导出了确定周期或准周期振动信号无标度区的经验公式 ,给出了盒维数的改进算法。验证结果表明 :盒维数的改进算法简单可靠。对汽轮机组轴瓦松动故障的分析说明 :盒维数可以作为识别振动信号复杂程度的一个新的无量纲指标。Fractal Box Dimension (BD), which can represent self-similarity and complexity of nonstationary vibration signal, provides a new tool for fault diagnosis of mechanical equipment. In this paper, we first analyze the shortcoming of conventional method for calculating BD of discrete vibration signal. Then we propose an improved algorithm of BD which include two key technologies. First, square box is replaced with rectangle box due to the biscale characteristic of vibration signal. Second, an empirical formula is derived for choosing scale-invariant region of periodic or quasi-periodic signals. Experimental results show that the improved algorithm of BD is simple and effective. As a successful application, BD is used to detect looseness fault in bearing bushing of turbo-generator set.

关 键 词：离散振动信号 双尺度 无标度区 盒维数 故障诊断 分形 

分 类 号：TH113.1[机械工程—机械设计及理论] TP277[自动化与计算机技术—检测技术与自动化装置]