1.School of Electrical and Automation Engineering, Hefei University of Technology, Hefei, Anhui 230009, China
2.Engineering Technology Research Center of Industrial Automation, Hefei, Anhui 230009, China
Abstract:Combining digital spectral analysis with analog band-pass filter group and adopting the micro-control unit MSP430F1611, a novel digital vortex flowmeter with the two-wire output is developed, which can the measuring range, ensure the measurement accuracy in fields, and operate in low-power. It solves the key technique problem in this kind of flowmeters. A programmable amplifier is constructed by an amplifier with low-power and digital potentiometers in order to adapt large change of amplitude of vortex sensor output. A band-pass filter group is selected by the computation result of small number FFT to cover the variation range of vortex frequency and perform optimal filter for the vortex signal. A power management module and current output circuit are designed to provide enough electrical current for meter operation with two-wire.
[1]Clarke D W, Ghaoud T. A dual phase locked loop for vortex flow metering [J]. Flow Measurement and Instrumentation, 2003, 14: 1-11.
[2]Xu K J, Huang Y Z, Lv X H. Power-spectrum-analysis-based Signal Processing System for Vortex Flowmeters [J]. IEEE Trans on IM, 2006, 55(3):1006-1011.
[3]徐科军,汪安民.基于自适应陷波的涡街流量计信号处理系统[J].计量学报,2000,20(3):199-204.
[4]莫德举,孙丽. 低功耗多变量涡街变送器的研究[J].仪器仪表学报,2002, 23(z3):860-862.
[5]胡海清,陈章位. 低功耗智能涡街流量计的设计[J].机电工程,2006,23(11):29-35.
[6]黄丹,陈昕,周康源. 利用MSP430芯片实现小波变换对涡街信号的去噪测量[J].数据采集与处理,2004,19(1):37-40.
[7]Masami Wada,et al. Vortex flowmeter: US6480812B1[P].2002-12.
[8]Masanori Hondoh, Masami Wada, et al. A vortex flowmeter with spectral analysis signal processing [C]// Sensor for Industry, 2001, Proceedings of the First ISA/IEEE Conference. Tokyo, Japan, 2001:35-40.