Multi-channel signal processing method for vortex flowmeter based on parallel filtering

Abstract

The vortex flowmeter holds a significant position in the field of flow measurement, owing to its advantages such as the absence of mechanical moving parts, adaptability to various media, and low pressure loss. The vortex signal detected by piezoelectric elements undergoes a series of amplification, filtering, and other processing steps through analog and digital circuits to achieve accurate flow measurement. To enhance the dynamic response of the vortex flowmeter, a multi-channel parallel signal processing method with a 1/$f^2$ amplitude–frequency modulation characteristic is proposed. By employing a 1/$f^2$ filter unit (–40 dB/dec) to lower the minimum detectable flow while keeping the maximum flow unchanged and thus increasing the turndown ratio, the measurement channel is divided into multiple parallel channels. A fast channel selection method is designed to effectively address the issue of slow dynamic response in vortex flowmeter signal processing. Results indicate that the vortex flowmeter, integrated with a four-channel algorithm, achieves a precision level of 0.5 and demonstrates superior dynamic response performance compared to Yokogawa flowmeters.