中文摘要：

针对变极距电容位移传感器提出了一种双频激励方法。同时采用低频、高频正弦电压源激励平板发射电极,通过电容耦合效应将极距变化转换为双频调幅信号,并通过高阻抗缓冲、带通滤波、精密整流电路获得双路位移调制电压信号。采用数字信号处理器（DSP）同步采集双路位移调制电压信号以及参考位移信号,对高、低频激励方式下的位移检测分辨率、纹波、动态响应速度等性能进行了对比分析。实验结果表明：双频激励时,通道间耦合作用较小,低频激励方式在位移分辨率、测量范围、线性度、抗干扰等指标上显著优于高频激励;高频激励在动态响应速度上具有明显优势。

英文摘要：

A dual-frequency excitation method was proposed for variable gap capacitive displacement sensor, in which, the stator was driven by a couple of sinusoidal voltage signals with low and high frequency. Through capacitance coupling and modulation circuit, a relative displacement between stator and mover of the transducer was converted to dual sync displacement-modulated voltage signals. The displacement detection resolution, static ripples and dynamic response were acquired and analyzed using digital signal processor（DSP）. The obtained data indicates that dual-frequency excitation emerges very low inter-channel coupling interference, and the low frequency excitation shows significant superior in displacement resolution, measuring range, linearity and anti-interference performance while the high frequency excitation has obvious advantages in dynamic response.