利用数字信号处理理论与技术提出了一种阻抗参数测量新方法,即采用任意的周期信号作为测量的激励信号,激励信号的信噪比可以很低;采用高镜频抑制比的数字正交采样滤波器得到被测阻抗和标准阻抗上的电压采样序列的同相分量与正交分量,并据此确定被测阻抗参数,该方法能得到较高的阻抗参数测量精度和较宽的测量范围,并且硬件电路实现比较容易。文中给出了计算机仿真分析和硬件实现系统的实验结果,证明了新方法的有效性和正确性。
A new impedance measurement method is used using the theory and technique of digital signal processing. The driving signal can use any periodic signal and its signal-to-noise ratio is very low. A special digital quadrature sampling digital filter algorithm is adopted with high mirror frequency rejection to obtain the I & Q sequences. The sequences are used to confirm the parameter of the impedance under measurement. The new impedance measurement method has the characters of wide measurement range and high accuracy. Thus its hardware system is relative simple and can be easily implemented on projects. The algorithm analysis, computer simulation and experimental results demonstrate that the method is effective. The new method develops impedance measui'ement technique and has a wide application in high accuracy impedance measurement field.