基于开关电容技术的信号跟踪滤波方法及其在转子动平衡中的应用

Signal Tracking Filtering Method Based on Switched-capacitor and Its Applications in Dynamic Balance of Rotors

为了满足转速波动时高精度动平衡测试的需求,精确、快速地分离出不平衡响应中的同频振动分量,利用开关和电容可等效为电阻的原理,导出了开关电容跟踪滤波方法,研制了一种新的开关电容模拟窄带跟踪滤波器,并对滤波器主要性能指标进行了测试与应用验证。试验结果表明:开关电容窄带跟踪滤波器有良好的跟踪特性,其中心频率由开关控制脉冲频率确定,是一种恒品质因素和恒定幅值增益的带通滤波器,具有良好的线性度。

In order to adapt to the requirements of high-precision dynamic balancing measurement with rotating speed variation and to isolate the vibration fractional factor with rotating frequency from unbalance response precisely and quickly, the tracking filtering method using switched-capacitor was deduced from the equivalent resistance principle between switch and capacitor,and a switched-capacitor narrow-band tracking filter was designed and used in measurement of rotor unbalance-induced vibration signals. The testing results indicate that the tracking characteristic of the filter is excellent, the center frequency is determined by the frequency of switching control pulse, and the tracking filter is a favorable linear band-pass filter with fixed quality factor Q-value and amplitude gain.