基于零相位数字带通滤波的旋转机械不平衡量提取方法
2019年 第1期
仪表技术与传感器
Instrument Technique and Sensor
2019 No.1
基金项目:天津市科委青年基金项目(15JCQNJC42100);天津市科技特派员项目(16JCTPJC48100,16JCTPJC47200)收稿日期:2017-12-05
基于零相位数字带通滤波的旋转机械不平衡量提取方法
荣 锋1,2,黄 晨1,郭翠娟1,2,董攀浩1
(1.天津工业大学电子与信息工程学院,天津 300387;
2.天津工业大学,天津市光电检测技术与系统重点实验室,天津 300387)
摘要:针对动平衡测试中FFT 频谱法难以从非整周期采样信号中提取不平衡相位的问题,提出一种基于零相位数字带通滤波提取旋转机械不平衡量的方法三首先将采集的振动信号通过中心频率为转速频率的零相位带通滤波器,得到无相位差的转速同频信号,然后计算信号峰值点幅值和相位的算数平均值,得到不平衡量三实现了非整周期采样下不平衡幅值和相位的精确提取三仿真和实测验证了方法的有效性,相位提取误差小于2?,动平衡效率大于80%三该方法无需专门的硬件跟踪滤波电路,具有较高的工程实用价值三
关键词:动平衡;FFT;非整周期采样;零相位滤波;时域提取;算术平均
中图分类号:TP216;TH17 文献标识码:A 文章编号:1002-1841(2019)01-0112-06
Method for Extracting Imbalance of Rotating Machinery
Based on Zero Phase Digital Band-pass Filter
RONG Feng 1,2,HUANG Chen 1,GUO Cui-juan 1,2,DONG Pan-hao 1
(1.College of Electronics and Information Engineering ,Tianjin Polytechnic University ,Tianjin 300387,China ;
2.Tianjin Key Laboratory of Optoelectronic Detection Technology and Systems ,
Tianjin Polytechnic University ,Tianjin 300387,China )
Abstract :Aiming at the problem that FFT spectral method is difficult to extract unbalanced phase from non-periodic sam-pling signal in dynamic balance test,a method based on zero-phase digital band-pass filtering to extract the imbalance of rotating machinery was proposed.First,the collected vibration signal was passed through the zero-phase bandpass filter whose center fre-quency is the speed frequency,and the same frequency signal with no phase difference was obtained.Then,the arithmetic average
of the amplitude and phase of the signal peak point was calculated to obtain the imbalance.It realized accurate extraction of unbal-ance amplitude and phase under non-integer period sampling.The validity of the method was verified by simulation and measure-ment.The phase error is less than 2?and the dynamic balance efficiency is more than 80%.This method does not require special hardware tracking filter circuit,and has high engineering value.
Keywords :dynamic balance;FFT;non integer period sampling;zero phase filtering;time domain extraction;arithmetic average
0 引言
由于转子材质不均,形状不对称等因素,旋转机械在运行中通常会产生不平衡现象,导致机械振动二磨损,降低使用寿命[1]三为了消除这种情况,必须对转子实施动平衡[2]三动平衡操作即在适当的角度添加相应配重以抵消不平衡,但前提是要精确地获取不平衡的相位和幅值,即不平衡量三如何准确获取不平衡量是动平衡成功与否的关键三
由于转子不平衡产生的振动响应与转速同频,因
此,通常同时采集转速和振动信号,以转速信号作为参考来获取与之同频的振动信号,然后通过各种分析方法提取不平衡量三目前,不平衡量的提取方法主要有时域提取法二频域提取法以及时频分析法三时域提取法主要采用硬件转速跟踪滤波法[3-4],陶利民等[3]提出采用开关电容窄带通跟踪滤波电路提取不平衡信号,该方法具有转速跟踪滤波性能良好的特性,但需要专门的硬件滤波电路支持;频域提取法主要采用FFT 基频提取法[5-7],胡庆翰等[6]提出采用FFT 实现高精度提取不平衡振动信号,但必须对信号整周期采样才能获取准确相位[5,7-8],由于转速波动是客观存在的[3-4],所以信号整周期采样实现困难;时频分析法是以经验模态分解理论[9-11]为基础提取不平衡量的方