基于机器视觉的共轨针阀尺寸参数在线测量监控系统的研究与开发

发布时间：2018-01-03 01:09

本文关键词：基于机器视觉的共轨针阀尺寸参数在线测量监控系统的研究与开发　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：共轨喷油嘴针阀偶件是柴油机燃油喷射系统的三大精密偶件之一,在工业大马力柴油发动机以及轻型客、轿车柴油发动机上均有使用,是保证柴油发动机燃油喷射系统稳定运行的关键部件之一,其精度要求高、产量大,相应地测量精度、检测效率等要求也随之提高。如何实现共轨针阀零件尾部尺寸参数的快速、稳定、高效、高精和全数在线测量,是目前工业生产中亟待解决的问题。本文围绕某外资企业喷油嘴共轨针阀零件的尾部尺寸参数测量与过程控制所展开。针对视觉在线测量系统的精度、效率、稳定性、完整性等难点,在系统平台的整体设计、图像高精度处理、系统参数标定、光机电一体化控制及系统开发等方面进行了一定的研究。本文的主要研究内容和成果如下:首先,进行视觉在线测量监控系统的整体设计。具体包括光学视觉系统硬件选型匹配和运动机构方案设计。结合目标零件轮廓特征、待测尺寸、企业生产线状况,确定光学视觉系统的打光方式,并进行相机、镜头及光源的选型;基于光源在视觉系统中的重要性,定性研究了复合光和单色光对测量系统的影响,得出单色光在背光方式中效果优异;同时,研究了光强与轮廓像素定位之间的关系,得出本文视觉系统在某一光强范围内,效果达到最优;根据待测零件特征,确定上料输送、定位及分拣运动机构方案。其次,对光学系统获取的共轨针阀图像进行处理算法设计。在降噪方面,通过滤波对比实验,选择了中值滤波算子,引入基于中值滤波的小区域滤波算法,大大缩短了滤波时间;在轮廓边缘检测方面,通过对比实验,引入了基于Sobel的小区域定向搜索边缘检测算法,提高了边缘定位效率,并采用小区域边缘特征点跟踪方法,基于学习训练逻辑,完成目标特征点定位;在边缘亚像素定位和拟合方面,引入基于稳健线性回归的直线拟合方法,在特定小区域下完成高精度边缘拟合,并完成直径、角度、距离的多参数同时计算。然后,深入地进行了视觉系统标定的理论研究与设计。对相机系统的参数标定、镜头的光学畸变及校正等进行了说明;分析研究了时下常用了标定方法,基于Microscape软件系统,采用两步标定法,完成相机内外参数及镜头畸变的标定与校正;运用标准网格及标准件,对相机位置及像素当量进行校准和计算。接下来,对在线视觉测量监控系统软件、硬件控制进行了具体的设计与开发。在Microscape视觉系统下设计图像算法处理过程,并基于VB完成了其在视觉检测、控制、统计计算、人机交互等方面的二次开发;同时基于统计学理论设计了工序质量实时监控系统,为生产线的实时在线监控、统计和分析提供完整应用;运用CATIA软件对整体自动化机构进行设计,完成整体上料输送、定位夹紧及下料分拣机构的三维图绘制,并设计了系统工作流程、自动化设备的通信与控制,完成整套系统的逻辑与运行控制。最后,进行了样机研制与可靠性评价,通过测试,运行情况良好。借助专用的Q-DAS数据统计分析软件,对样机平台系统的稳定性、偏倚能力指数、重复再现性进行实验及分析评价,统计分析表明样机对共轨针阀零件尾部直径、角度、距离的尺寸测量,在公差范围内达到了10倍以上的测量精度,系统亚像素分辨率达到了0.0008~0.0003mm,满足了工业实际应用需求;并以直径参数为例,测试了平台的工序质量实时监控统计系统,验证了本文的理论研究成果的可行性、有效性。本文完成了共轨针阀零件的尾部尺寸参数在线测量监控系统的研究与开发,对其他同类产品的在线测量具有重要的借鉴作用。
[Abstract]:The common rail injector needle valve is one of the three big precision coupling of fuel injection system in diesel engine industry, and light passenger car diesel engine are used, is to ensure that the diesel engine fuel injection system is one of the key components of its stable operation, high precision, large output, the corresponding measurement accuracy so, the detection efficiency requirement is increasing. How to realize the common rail valve parts tail size parameters of fast, stable, high efficiency, high precision and full online measurement, is the current industrial production problems to be solved. This paper focuses on a foreign enterprise common rail injector needle valve parts of the tail size parameter measurement and process control. According to the visual online measurement system accuracy, efficiency, stability, integrity and other difficulties, in the overall design of system platform, high precision image processing, system calibration, optical electromechanical The research of integrated control and system development. The main research contents and results are as follows: firstly, the overall design of measuring and monitoring system for visual online. Including the design of optical vision system hardware matching and motion mechanism scheme combining the target contour features, the size to be measured, the enterprise production line status determination of the optical visual system lighting methods, and selection of camera lens and light source; light importance in the vision system based on the qualitative research on the effects of compound light and monochromatic light on the measurement system, the monochromatic light in the backlight in excellent effect; at the same time, study the relation between the light intensity and the contour pixel location. The visual system in a certain intensity range, to achieve the optimal effect; according to the features of parts to be measured to determine material conveying, sorting and positioning movement mechanism second scheme, Processing algorithm design of common rail valve image optical system is obtained. In denoising, filtering through the contrast experiment, choose the median filtering operator, introduce small domain filtering algorithm based on median filtering, greatly shorten the filtering time; in the edge detection, through the contrast experiment, introduces the search algorithm of edge detection area orientation based on Sobel, and improves the edge localization efficiency, and the tracking feature point area edge training logic based on target feature points, positioning; in sub-pixel edge locating and fitting, introducing the linear fitting method of linear regression based on the completion of high precision edge fitting in specific area, and complete the diameter at the same time, angle, distance calculation of multi parameter. Then, in-depth theoretical research and design of the vision system calibration. The calibration parameters of the camera lens system. The head of the optical distortion and correction are described; analysis of the nowadays commonly used calibration method, based on Microscape software, using two step calibration method, calibration and calibration of camera parameters and lens distortion; using standard grid and standard parts, calibration and calculation of the camera position and the pixel equivalent. Next, the online visual measurement monitoring system software, hardware control is designed and developed. The design of specific image processing algorithms in the process of Microscape vision system based on VB, and completed its control in visual inspection, statistical calculation, two times the development of human-computer interaction and so on; at the same time, based on statistical theory and design of real-time monitoring system of process the quality of real-time online monitoring for production line, to provide a complete application of statistics and analysis; application of integrated automation mechanism design CATIA software, complete the whole conveying, set A three-dimensional map of clamping and cutting the sorting mechanism is drawn, and the design of the workflow system, communication and control automation equipment, complete set of logic and operation control system. Finally, the prototype development and reliability evaluation, through the test, running in good condition. With the help of Q-DAS data for statistical analysis software, the stability of the prototype the platform system, the bias capability index, repeatability of experimental evaluation and analysis, statistical analysis showed that the prototype of common rail valve parts, tail diameter, distance measurement, the measurement accuracy reached more than 10 times in the tolerance range, sub-pixel resolution system has reached 0.0008~0.0003mm, and meets the requirements of industrial application; and the diameter of parameters for example, process quality real-time monitoring and statistical system platform test, verify the feasibility of this paper, the theoretical research results. The validity of this paper. It has become the research and development of on-line measurement and monitoring system for tail size parameters of common rail needle valve parts, which has important reference for other similar products online measurement.

【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP391.41;TP277

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