基于Laguerre滤波的超声波流量计降噪方法研究*

作者：刘丽B，鲍敏，沈卫平 日期：2009-11-16/span> 浏览：3621 查看PDF文档

基于Laguerre滤波的超声波流量计降噪方法研究*

刘丽B，鲍敏，沈卫平
(浙江理工大学 机械与自动控制学院，浙江 杭州 310018）

摘要：针对气体超声波流量计利用过零检测定位波形脉冲时的干扰因素，以及计算系统对数据处理实时性的要求，对基于Laguerre滤波的递归最小二乘（RLS）降噪算法进行了研究，实现了在处理速度与稳定性上的折中。为信号后处理提供了理想的波形，避免了波形失真导致脉冲漏检、零位判断错误等误差因素的产生，给出了实时性强、波形定位准确、系统稳定性和抗干扰性能良好的气体超声流量计信号处理算法。研究结果表明，基于此算法的气体超声波流量计经检验具备2级精度。
关键词：气体超声波流量计；过零检测；Laguerre滤波；递归最小二乘
中图分类号：TB126文献标识码：A文章编号：1001-4551(2009)09-0054-03

Denoising study for ultrasonic gas flow measurements based on Laguerre filter
LIU Lijun, BAO Min, SHEN Weiping
(Faculty of Mechanical Engineering & Automation, Zhejiang SciTech University, Hangzhou 310018, China)
Abstract: Aiming at the interfering factors that exist at zerocross point and the real time of data processing in gas ultrasonic flowmeter, a Laguerre filter based recursive least squares (RLS) adaptive technique was studied to achieve a compromise between processing speed and stability of the system. The ideal waveform for the follow processing was provided, the waveform distortion resulting in missed pulses, wrong tracking of zerocross point and other error factors were avoided. The signal processing algorithm was applied to get good antiinterference performance, reconstruct a normalized and high signal to noise ratio(SNR) echo wave, and improve stability of system. The research results show that precision of this gas ultrasonic flowmeter achieves 2%.
Key words: gas ultrasonic flowmeter; digital processing; Laguerre filter; recursive least squares(RLS)
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