摘要
复调制带通滤波器具有负频率为零、冲击响应函数实部和虚部有 90°相移的特点 ,能将带通滤波和希尔伯特变换合为一体 ,只要选择合适的滤波参数 ,在解调分析中将不包括故障信息的时域相加信号滤掉 ,且能避免广义检波滤波解调分析中的混频效应。利用此原理 ,并将最大细化倍数与带通滤波器的宽度之间建立了严格的数学关系 ,以避免为了大幅度提高运算速度而只对选抽点进行变换可能产生的频混现象 。
A multiple analytic band-pass filter is characterized by zero amplitude of negative frequency and 90° phase-shift in the real part as well as in the imaginary part of its impulse respons function. By combining band-pass filtering with Hilbert transformation, Those time-domain adding signals will be reject without fault information in the process of demodulation. Meanwhile, the aliasing effect of generalized detect-filter demodulation analysis can be avoided. Sub-sampling points are normally transformaed to improve the speed of calculation. However,this may cause aliasing effect. But now it can be eliminated the aliasing with the help of the band-pass filter under a strict relation of maximal zoom time and band-pass filter width. So this method optimizes the narrow-band Hilbert demodulation algorithm., which is widely employed in fault diagnosis.
出处
《振动工程学报》
EI
CSCD
2000年第3期385-392,共8页
Journal of Vibration Engineering
