变速机械振动信号的伪同步重采样技术——Ⅰ速度与角位置的瞬时估计方法

在机械的变速运行过程中,由于存在非平稳性,使得大部分等时间间隔采样的传统方法无法适用。利用光电编码器进行角域采样虽可以快速跟踪转速的变化,但其使用安装却要受机械装置结构的限制。为解决机械变速过程状态信号的解调和特征提取问题,本文提出了一种新的数据获取和预处理方法——伪同步信号重采样技术。该技术通过对瞬时转速和角位置的估计以及对非平稳信号的自适应重采样,获取了与转速有关的信息并应用常规的信号处理方法进行特征提取。 本文主要探讨转速和角位置的瞬时估计。计算机仿真和实验验证的结果表明,改进型三次样条函数插值可以给出足够精度的估计结果。

PSEUDO-SYNCHRONOUS SIGNAL RESAMPLING OF VARYING SPEED MACHINERY VIBRATION-I. ESTIMATION OF INSTANTANEOUS SPEED AND ANGLE POSITION

Varying speed machinery monitoring is fraught with difficulties on non-stationary machine dynamics and vibrations. Most conventional digital signal processing methods become in-appropriate when monitoring the vibrations of varying speed machinery. Angular sampling using optical encoders, can track rapidly fluctuating speed, however, its practicable area is restricted in reality. Part I and part II of this paper present a new data acquisition technique-Pseudo-syn-chronous Signal Resampling, which pre-processes varying speed signal so that conventional signal processing methods can be applied. It is based on the estimation of instantaneous speed and angle postition, and adaptive signal resampling to non-stationary machinery signals.The present paper, part I , is primarily concerned with the estimation of instantaneous speed and angle position. It will show that the improved spline interpolation can give the estimate result in enough precision. The approach is implemented and validated by computer simulation and experiment.