一些工业现场存在较强振动干扰,其频率在涡街流量信号的范围内,且功率大于涡街流量信号的功率。采用数字涡街流量计根据流量信号占优原则来确定流量频率,就无法得到正确的测量结果。为此,设计了陷阱频率、陷阱宽度和陷阱深度可任意调节的陷波滤波器。采用陷波滤波器消除固定强干扰;用功率谱分析计算出涡街流量信号的频率。消除了在涡街流量信号范围内的强固定干扰,又不影响流量的测量。用Microchip公司的dsPIC33FJ256MC710 DSP研制了涡街流量计信号处理系统,并取得很好的实验效果。
Abstract
There is strong-vibration-disturbance in industrial fields sometimes. The frequency of the disturbance is fixed and within the range of the vortex flow signal. Its power is large than that of the vortex flow signal. At this time, the digital vortex flowmeter can not obtain accurate measurement results according to the vortex flow signal power being maximal. Therefore a notch filter with adjusted frequency, width and depth is designed. The notch filter is firstly used to remove the fixed-strong-disturbance, and then the spectrum analysis is employed to estimate the frequency of the vortex signal, which can attenuate the fixed-strong-disturbance that is within the frequency range of the vortex flow signal, and not to affect measurement of the vortex frequency. A dsPIC33FJ256MC710 DSP made by Microchip Company is used to develop a digital signal processing system for vortex flowmeter, and the good experimental results are obtained.
关键词
计量学 /
涡街流量计 /
强固定干扰 /
陷波滤波器 /
数字信号处理器
Key words
Metrology /
Vortex flowmeter /
Fixed-strong-disturbance /
Notch filter;Digital signal processor
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
［1］Amadi-echendu J E, Zhu H J, Higham E H.Analysis of signal from vortex flowmeters［J］. Flow Measurement and Instrumentation, 1993, 4( 4), 225-231.
［2］徐科军.涡街流量计输出信号谱分析比较［J］. 合肥工业大学学报, 1994,17(2):6-11.
［3］Xu K J, Huang Y Z, Lv X H, Power-spectrum-analysis-based Signal Processing System for Vortex Flowmeters［J］. IEEE Trans on Instrument and Measurement, 2006, 55(3):1006-1011.
［4］Ukil A, Andenna A. Harmonic analysisb-based diagnostics of noflow pulsation in vortex and swirl flowmeter［J］. Digital Signal Processing, 2009, 19:700-707.
［5］王肖芬, 徐科军, 陈智渊. 基于DSP的低成本涡街流量计信号处理系统［J］. 仪器仪表学报,2006,27(11):1427-1432.
［6］Xu K J, Zhu Z H, Zhou Y. Applied digital signal processing systems for vortex flowmeter with DSP［J］. Review of Scientific Instruments,2009, 80(2):025104（10 pages).
［7］Nehorai A. A Minimal Parameter Adaptive NotchFilter with Constrained Poles and Zeros［J］. IEEE Trans Acoust, Speech, Signal Processing, 1985,33,(4): 983-996.
［8］Ng T S. Some Aspects of an Adaptive Digital Notch Filter with Constrained Poles and Zeros［J］. IEEE Trans Acoust, Speech, Signal Processing, 1987,35( 2):158-161.
［9］Stoica P, Nehorai A. Performance Analysis of an Adaptive Notch Filter with Constrained Poles and Zeros［J］. IEEE Trans. Acoust, Speech, Signal Processing, 1988,36(6): 911-919.
PDF(575 KB)
