转子强脉冲干扰非线性信号的混合滤波方法研究

针对脉宽调制控制器在转子振动信号中产生的强脉冲及其它随机干扰噪声，对信号的滤波方法进行了研究．设计了将中值滤波与小波消噪串联的混合滤波器对非线性信号进行滤波的方案．通过对信号的前后周期延拓，将中值滤波用于滤除信号的强脉冲噪声并消除信号的边缘保持；对线性叠加在中值系列中的平稳随机噪声，用默认软阈值小波消噪平滑中值序列中的随机噪声分量，分析表明，该滤波器对该类振动信号的处理效果好，提取到了转子的本质振动信号并保持了信号的光滑性．

Investigation of integrated filtering method for nonlinear signals with violent pulse interferences of rotors

Aimed at the violent pulses and other stochastic noises generated by the pulse width modulating controller in a vibrational signal of the rotor,a method for the signal filtering is investigated.A scheme of integrated filter with a serial circuit of median filtering and wavelet de-noising is designed for the nonlinear signal filtering.By means of delaying the periods before as well as behind the signal,the violent pulse noises are filtered off from the signal and the edge holding is also eliminated by using the median filtering.As for the stable stochastic noise component linearly superposed on the median series,it is smoothed by means of the default soft threshold wavelet de-noising.It is shown by the experiment that,by using this filter,the treatment effect of this kind of vibrational signals is good,the true vibration signal of the rotor is extracted out,and the smoothness of the signal is maintained.