›› 2015, Vol. 35 ›› Issue (2): 77-.doi: 10.3780/j.issn.1000-758X.2015.02.011

• 研究探讨 • 上一篇    

小管径超声波流量计去噪方法

  

  1. (1北京航空航天大学机器人研究所,北京100191)(2北京控制工程研究所,北京 100190)
  • 出版日期:2015-04-25 发布日期:2015-04-25

Research on Denoising Method for Small PipeUltrasonic Flow Meter

  1. (1 Robotics Institute, Beijing University of Aeronautics and Astronautics, Beijing 100191) (2 Beijing Institute of Control Engineering, Beijing 100190)
  • Online:2015-04-25 Published:2015-04-25

摘要: 超声波流量计中存在各种噪声,直接影响流量测量的精度。文章首先分析了小管径超声波流量计中噪声的来源,从实时性的角度出发,提出了一种直接对测量时间差进行去噪的方法,避免了对原始超声波信号进行采样、分析带来的实时性差的问题。针对随机噪声和声学噪声引起的时间差数据中的误差,以硬阈值小波滤波作为第一级滤波、中值加均值滤波为第二级滤波进行处理。通过流量测量实验,验证了去噪方法的有效性,结果表明,去噪后流量计的瞬时测量误差小于1%。

关键词: 超声波流量计, 在轨加注, 小波滤波, 中值加均值滤波, 航天器

Abstract: The noise will directly affect the accuracy of the ultrasonic flow meter. The sources of noise inside the small pipe ultrasonic flow meter were analyzed. Considering the critical real-time measurement for the flow meter, a method of directly denoising the transit-time difference data was proposed. It avoided sampling and analyzing the original ultrasonic signal, which might lead to the poor performance of real-time measurement. For different noise sources, two different kinds of filters were applied. The wavelet filter was chosen as the first denoisng filter, which used a hard thresholding to reduce error from the random noise. A median filter and a mean filter were combined as the second denoisng filter to reduce error from the acoustic noise. The flow rate measurement experiment was implemented to verify the validity of the proposed denoising method. The results show that the instantaneous measurement error can be less than 1% after denoising.

Key words: Ultrasonic flow meter, In-orbit refueling, Wavelet filter, Median and mean filter, Spacecraft