用于电磁流量计信号调理的数模混合最优滤波方法

摘要

According to the characteristics of inductive signal, interference and noise from electromagnetic flowmeter excited with low frequency square waveform, an optimal mixed-signal filtering method was pro-posed. The principle of optimal mixed-signal filtering method and its mechanism on the way to eliminate or suppress interference and noise were analyzed theoretically. The principle deviation and its compensa-tion of this method were also analyzed . An electromagnetic flowmeter was designed to apply this method. Theoretical analysis and the result of verification experiment both show that the optimal mixed-signal filte-ring method is an effective method to eliminate differential noise. In electromagnetic flowmeter, not only the differential noise is removed, but other kinds of interference and noise are also suppressed effectively. This makes the output signal with higher signal-noise ratio.%针对采用低频矩形波励磁的电磁流量计感应信号、干扰和噪声信号的特性，提出了基于数模混合最优滤波方法的信号调理方案。对数模混合最优滤波方法的原理和消除、抑制干扰和噪声的机制进行了理论分析，分析了该方法的原理误差及补偿方法，在此基础上设计了电磁流量计。理论分析和检定实验表明数模混合最优滤波法是一种有效消除微分噪声的方法，它既能除去电磁流量计的微分噪声，又能有效降低其他各类噪声干扰，从而获得更高信噪比的流量信号。