摘要
为了保证燃烧流场羟基(OH)示踪速度测量的精度,开展了背景噪声去除方法研究。基于燃烧流场羟基示踪测速数据的噪声特性分析,构建了染噪的数值模型;针对局部的燃烧OH荧光干扰以及流场杂散光等背景噪声,采用了基于Hough变换的空间滤波方法。针对测量系统的物理、电、光以及传感器等噪声,采用了小波变换的噪声去除方法,提高了图像信噪比。提出了一种将两种方法融合的背景去除方法,抑制了系统噪声对空间滤波算法精度的影响,优化了空间滤波结果。研究结果表明,图像处理后峰值信噪比提高了16.79 dB,信噪比提高了13.91 dB。对燃烧流场实验数据进行了处理,有效地抑制了背景噪声,达到了图像预处理的效果,满足了激光诊断系统对测量精度的要求。
In order to guarantee the precision of hydroxyl(OH)tagging velocimetry measurement in combustion flow field,we investigate a background noise removal method.Based on the analysis of noise characteristics of hydroxyl tagging velocimetry experimental data in combustion flow fields,we construct a numerical model of noise attenuation.For the background noise such as local combustion OH fluorescence interference and flow stray light,we adopt a spatial filtering method based on Hough transform.As for the physical,electrical,optical and sensor noises of the measurement system,we present a noise removal method of wavelet transform to improve signal-to-noise ratio.The background noise suppression method combining spatial filtering and wavelet transform is proposed to suppress system noise effect on the spatial filtering algorithm precision,and optimize the spatial filtering results.The research results show that the peak signal-to-noise ratio is improved by 16.79 dB,and signal-to-noise ratio is improved by 13.91 dB after imaging processing.The experimental data of combustion flow field are processed,which effectively suppresses background noise,achieves the effect of image preprocessing,and meets the requirement of measurement accuracy of laser diagnostic system for measurement accuracy.
作者
邵珺
叶景峰
王晟
胡志云
方波浪
张振荣
李景银
Shaojun;Yejingfeng;WangSheng;HuZhiyun;FangBolang;Zhang Zhenrong;Li Jingyin(School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an,Shaanxi 710049,China;The State Key Laboratory of Laser Interaction,with Matter,Northwest Institute of Nuclear Technology,Xi'an,Shaanxi 710024,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2019年第3期236-246,共11页
Chinese Journal of Lasers
基金
国家自然科学基金(91541203
91641112)
国家重点实验室基金(SKLLIM1808)
关键词
图像处理
燃烧流场
羟基示踪测速
噪声去除
HOUGH变换
小波变换
image processing
combustion flow field
hydroxyl tagging velocimetry
noise removal
Hough transform
wavelet transform
作者简介
邵珺,E-mail:shaojun@nint.ac.cn.
