无转速计阶比分析方法研究

发布时间：2018-01-02 02:00

本文关键词：无转速计阶比分析方法研究　出处：《沈阳大学》2016年硕士论文　论文类型：学位论文

【摘要】：旋转机械已经成为工业中的关键性设备,许多旋转机械都是在变载荷和变转速工况下运行的,并且随着对转速要求的提高,转速波动带来的影响越来越不容忽视。旋转机械升降速过程及变速工况中的振动信号蕴含丰富的故障信息,对故障诊断具有独特的价值。阶比跟踪分析是变速工况下旋转机械振动信号分析的一种有效方法。传统的阶比分析方法一般都含有转速计、光电编码器等硬件设备,虽然可以获得较高的分析精度,但其安装场合受限,限制了阶比分析方法在实际中的应用。因此研究一种行之有效的无转速计阶比分析方法已成为目前的一个研究热点。针对这一问题,本文研究了一种基于瞬时频率估计的无转速计阶比分析方法。本文主要工作如下:对常见的旋转机械故障机理进行了分析,介绍了各种故障下振动信号的对应特征。无转速计阶比分析方法有效估算信号的瞬时频率是获取转速信息的前提,针对旋转机械在变速工况下的振动信号具有非平稳性及多分量的特性,本文首先采用EMD方法对振动信号进行分解,基于相关系数法提取敏感IMF分量,然后分别采用Hi1bert法和Teager能量算子法对其进行瞬时频率估计,对比分析后发现Hi1bert变换方法能够清晰地表征信号的瞬时频率。为了消除EMD端点效应问题对瞬时频率分析精度的影响,对瞬时频率曲线进行了分段平滑处理,以减少瞬时频率的误差,提高瞬时频率估计的精度,仿真实验验证了分段拟合方法的有效性。为了验证无转速计阶比分析方法的有效性,搭建了转子不对中系统振动实验台,结合不对中故障机理,对采集的振动信号进行分析研究,实验结果验证了本文所提出的无转速计比分析方法的可行性及有效性。
[Abstract]:Rotating machinery has become the key equipment in industry, many rotating machinery are running under variable load and variable speed conditions, and with the increase of speed requirements. The effect of rotating speed fluctuation is more and more important. The vibration signal of rotating machinery contains abundant fault information in the process of speed rise and fall and in the variable speed condition. Order tracking analysis is an effective method for vibration signal analysis of rotating machinery under variable speed conditions. Traditional order analysis methods generally contain tachometers. Although the photoelectric encoder and other hardware equipment can obtain high analysis accuracy, its installation situation is limited. The application of order analysis method in practice is limited. Therefore, the study of an effective order ratio analysis method without tachometer has become a hot research topic at present. In this paper, a method of order ratio analysis without tachometer based on instantaneous frequency estimation is studied. The main work of this paper is as follows: the common fault mechanism of rotating machinery is analyzed. The corresponding characteristics of vibration signals under various faults are introduced. The effective estimation of the instantaneous frequency of signals is the premise of obtaining rotational speed information by using the order ratio analysis method without tachometer. Aiming at the non-stationary and multi-component characteristics of vibration signals of rotating machinery under variable speed conditions, this paper firstly uses EMD method to decompose the vibration signals and extract the sensitive IMF components based on the correlation coefficient method. Then the instantaneous frequency is estimated by Hi1bert method and Teager energy operator method. It is found that the Hi1bert transform method can clearly represent the instantaneous frequency of the signal. In order to eliminate the effect of the EMD endpoint effect on the accuracy of instantaneous frequency analysis. In order to reduce the error of instantaneous frequency and improve the accuracy of instantaneous frequency estimation, the instantaneous frequency curve is processed by piecewise smoothing. In order to verify the effectiveness of the order ratio analysis method without tachometer, the vibration test bench of rotor misalignment system is built, and the mechanism of misalignment fault is combined. The vibration signals collected are analyzed and the experimental results verify the feasibility and effectiveness of the non-tachometer ratio analysis method proposed in this paper.
【学位授予单位】：沈阳大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH17

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