基于机器视觉的光学雨滴谱仪方案研究与实现  

Research and implementation of optical raindrop spectrometer based on machine vision

作　　者：赵鹏[1] 张洪玮 吴松华[1,2] ZHAO Peng;ZHANG Hongwei;WU Songhua(College of Marine Technology,Faculty of Information Science and Engineering,Ocean University of China,Qingdao 266100,China;Laboratory for Regional Oceanography and Numerical Modeling,Laoshan Laboratory,Qingdao 266237,China)

机构地区：[1]中国海洋大学信息科学与工程学部海洋技术学院,山东青岛266100 [2]崂山实验室区域海洋动力学与数值模拟功能实验室,山东青岛266237

出　　处：《大气与环境光学学报》2024年第6期611-623,共13页Journal of Atmospheric and Environmental Optics

基　　金：国家自然科学基金(42106182,61975191);山东省自然科学基金青年项目(ZR2021QD052)。

摘　　要：雨滴谱是描述降水微物理特征的重要参数,对于改善雷达定量降水估计、研究降水微物理性质及认识降水演变过程具有关键作用。为实现雨滴的尺度和尾速的同步测量,本文提出了一种基于机器视觉原理的光学雨滴测量方法,设计了以双远心镜头、远心光源和线阵相机为核心的系统方案,并搭建了光学雨滴谱仪样机。数据处理与分析系统以微软基础类库(MFC)为框架,调用相机软件开发包(SDK),联合Halcon软件开发了一款雨滴实时自动化测量软件。利用Canny算法对所得图像进行亚像素边缘检测,使用插值算法修复雨滴轮廓,最后根据还原后的雨滴图像计算出雨滴的尺度和尾速,从而实现雨滴的自动化测量。利用钢球和水滴进行了定标检验,使用标准量棒实验对仪器测量范围进行了标定。检测结果表明该雨滴谱仪对0.6~5.0 mm之间的钢球直径测量误差小于21μm,速度反演误差小于4.5%;而对水滴的测量标准差为26μm,证明该仪器可以同时测量粒子的尺度和尾速,并在测量运动粒子方面表现出良好的准确性和一致性。Raindrop spectrum is a critical parameter for describing the microphysical characteristics of precipitation,so its accurate measurement plays a pivotal role in enhancing radar-based quantitative precipitation estimation,investigating microphysical properties of precipitation,and understanding the evolution process of precipitation.To achieve synchronous measurement of raindrop size and terminal velocity,we propose an optical raindrop measurement method based on machine vision principles,design a system with a dual telecentric lens configuration,a telecentric light source,and a linear array camera as the core,and constuct a prototype of an optical raindrop spectrometer in this paper.The data processing and analysis system of the spectrometer,is based on the Microsoft Foundation Classes(MFC)framework,and a real-time automated raindrop measurement software is developed utilizing the camera software development kit(SDK)in conjunction with Halcon software.The Canny algorithm is employed for subpixel edge detection of the acquired images,interpolation algorithms are applied to restore raindrop contours,and finally based on the restored raindrop images,the size and terminal velocity of raindrops are computed,thus achieving automated measurement of raindrops.Calibration tests are conducted using steel spheres and water droplets,with calibration of the instrument's measurement range being performed using a standard gauge block.The calibration results show that the raindrop spectrometer has a measurement error of less than 21μm and a velocity inversion error below 4.5%for steel sphere diameters between 0.6 and 5.0 mm,and the standard deviation for droplet measurements is 26μm,indicating that the instrument can concurrently measure particle size and terminal velocity,and has good accuracy and consistency in measuring moving particles.

关 键 词：雨滴谱仪 机器视觉 边缘检测 

分 类 号：P414.9[天文地球—大气科学及气象学]