机电液系统转速波动分量Vold-Kalman时变滤波提取方法

机电液系统的转速波动信号蕴含着丰富的系统运行状态信息,从该转速波动信号中通常可以观测到多个波动源的耦合现象。针对磁电式转速传感器输出的方波信号中转速波动分量的特征提取问题,提出了基于Vold-Kalman时变滤波的转速波动分量提取方法。首先利用采样点计数测速算法获得变转速泵控液压马达系统的瞬时转速信号;其次,结合短时傅立叶变换和二值细化处理得到的瞬时频率估计曲线作为中心频率,构造了基于转速波动信号特征模型的结构方程和数据方程;最后通过最小二乘滤波和PCG法求解,实现了转速波动分量时域波形的提取。实验结果表明:该方法能有效地提取变转速泵控马达系统中由柱塞马达输出轴转频及减速箱输出轴转频引起的转速波动,为机电液系统的状态监测和运行可靠性分析提供了新方法。

A Speed Fluctuation Component Extraction Method Based on Vold-Kalman Time varying Filte

The speed fluctuation signal of electro hydraulic system contains a lot of information about the operating state of the system, which is usually the coupling effect of multiple speed fluctuation sources. Aiming at the feature extraction of speed fluctuation component in square wave signal produced by magnetoelectric speed sensor, a method of speed fluctuation component extraction based on Vold-Kalman time varying filter was proposed. Firstly, the instantaneous speed signal of the system was obtained by sampling point counting speed measurement algorithm. Secondly, the instantaneous frequency estimation curve, which handled by the STFT and the binaryzation, was taken as the center frequency, and the structural equation and data equation based on the characteristic model of the speed fluctuation signal were constructed. Finally, the time domain waveform extraction of the speed fluctuation component was realized by least square filtering and PCG method. The experimental results show that this method can effectively extract the speed fluctuation caused by the the gearbox and the motor output shaft frequency of the variable speed pump controlled motor system, which can provide a new method of signal processing for online monitoring and fault diagnosis of electro hydraulic system.