【作者】 王克鸿；

【导师】 王执铨； 石连捷；

【作者基本信息】 南京理工大学 ， 控制科学与工程， 2007， 博士

【摘要】 本文针对机器人气体保护自动焊,进行了熔池(接缝)视觉的近红外自动传感、计算机图象处理、视觉图象缺陷特征建模、质量智能控制等研究工作。同时,在弧焊机器人工艺试验的基础上,设计研究了焊接工艺自动设计和在线参数传感与传输系统,研究内容主要包括:1.近红外熔池视觉图象传感技术方法本文针对射流、短路过渡和等离子加热熔池,提出了近红外视觉在线检测熔池过程图象的方法,在“鬼像”消除;近红外窄带-截止复合滤光;熔池、接缝、焊缝外观视觉一体化传感等方面取得突破,同时在等离子加热区及熔敷铜熔池;铝合金双丝焊熔池;等离子焊熔池等视觉传感及一体化传感器等方面开展了具有创新性的试验研究,获得了具有清晰特征的等离子加热区、TIG和等离子铜熔敷焊熔池、铝合金双丝焊熔池图象,解决了基于视觉的质量智能控制技术中视觉传感关键性难题。2.熔池图象特征提取方法本文将平滑、Sobel锐化、Canny水平算子、双浮动阈值分割、细化、断点连接、图象轮廓提取等计算机图象处理技术应用于熔池(接缝)视觉质量信息的提取。针对强弧光干扰熔池图象特征,给出了新的熔池、接缝、焊缝外观视觉专用计算机图象处理技术与软件系统,获得了清晰的熔池(接缝、焊缝)几何边界、浮渣等成型和质量特征,结合焊接工艺参数的传感采集,给出了分区域质量特征的图象处理方法,解决了熔池轮廓和特征提取等难题;在上述特征研究的基础上,发展了熔池形态和边缘特征描述方法,提出了较为系统的熔池视觉图象几何形态参数描述指标,主要包括:熔池面积、后拖角、尾部面积、尾部边缘光滑度、熔池视觉图象相对对称度等指标。3.熔池视觉图象与焊接缺陷关系本文基于熔池图象的形态、边缘及浮渣特征,首次研究给出了气孔、夹渣缺陷形成前熔池图象特征,如“熔池边缘呈锯齿状图形特征、熔池图像尾部出现黑斑点、浮渣数目增多、灰度均值波动和灰度标准差变大等”,给出了“上述特征可能单独出现也可能几个特征同时出现,产生上述图象特征虽不能肯定会产生气孔、夹渣缺陷,但产生气孔、夹渣缺陷的概率将大幅度增加”等具有创新性的结论。4.基于视觉传感的质量智能控制本文基于模糊神经网络等智能控制技术,建立了基于视觉传感的射流、射滴、短路过渡工艺的熔宽、熔深模糊神经网络控制模型,并对有干扰的工艺实验进行了深入的研究,并通过实验结果对相关模型进行了修正,实验结果表明具有很好地效果。本文首次针对等离子(TIG)铜熔敷焊,提出了基于视觉传感的质量自动控制方法,微观组织、电镜能谱、高分辨透射、力学性能等检测表明,铜钢界面实现了无熔深连接,铜和钢界面实现了原子间结合,研究和实验工作获得了具有创新性的结果。5.接缝熔池双目视觉传感技术本文在激光接缝跟踪研究的基础上,发展了激光视觉接缝几何参数传感与跟踪技术,设计研制出了结构激光双目视觉传感器,较好的解决了立体视觉中对应点的匹配问题,得到接缝特征点在二维平面上的图像坐标和坡口类型、角度、间隙等几何特征信息;采用三维重建算法,能由接缝特征点的图像坐标计算出其三维坐标,并能精确的得到V型、半V型、对接I型、U型、搭接等接缝三维几何尺寸。6.重型车辆弧焊机器人富氩气体保护焊工艺自动设计系统本文针对军工车辆焊接工艺的智能设计,提出并设计了富氩气体保护焊(PMIG、MIG、MAG和手工电弧焊)焊接工艺自动设计系统软件,解决了焊接产品信息的结构化和半结构化的表达和管理、基于规则和实验报告的焊接工艺卡的双推理、焊接CAD与工艺系统图形的无缝信息交互等基础性难题;实现了推理过程的多参数多规则约束的自动工艺求解、产品焊接工艺自动批输出等;设计开发了弧焊机器人焊接参数实时传感、发布和远程传输等软硬件关键技术,实现了焊接电流、电弧电压、焊速、熔池视觉图象等的传感和网络化传输。更多还原

【Abstract】 Taking gas shielded arc welding robot process as research object,a research of molten pool(seam)vision near infrared auto-sensing technology, computer image processing,visual image of defects modeling and quality intelligent control is made in this paper.Based upon the process experiments on arc welding robot,the welding procedure auto design and on-line parameter sensing technologY and transmission system are researched.1.Welding Pool Visual Image Sensing with Near Infrared TechnologyFor spray,short circuit transfer and plasma heated molten pool,a method of using near infrared sensing to detect pool image on-line is presented.A breakthrough at the aspects of avoiding ghost image,near infrared narrowband and cut-off compoundfiltering,molten pool,seam and weld appearance visual integrative sensing is made.Someinnovated experiments on molten pool visual sensing Of plasma heating and deposited,aluminum alloy welding with twin-wire consumable electrode and plasma welding is made.Some clear images of molten pool of ptasma heating zone,TIG and deposited welding for copper,alloy welding with twin-wire consumable electrode are acquired.The key difficulty in visual sensing of quality control technology based on vision is resolved.2.Welding Pool Image Characteristics ExtractionSome image processing methods such as smoothing,Sobel sharpening,Cannny level operator,double floatation threshold auto-division,morphologic filtering,refinement,breakpoint connecting and image contour extraction is applied in the extraction of molten pool(seam)visual quality information. Aim at the problem of strong arc light disturbing the molten pool image characteristics,a speciai computer processing technology and software system of the molten pool(seam)visual image is developed and a clear molten pool (seam)geometry boundary,scum forming and quality characteristics is acquired.Combining the welding process parameters sensing and collection, an image processing method of disparting region quality characteristics is brought forward and the difficulty of molten pool contour and characteristics extraction is resolved.Based on above research,the describing method of molten pool(seam)visual image shape and characteristics is developed.And a new systemic parameter index for describing the molten pool(seam)visual image geometry shape is brought forward.The detailed indexes include molten pool area,drag angle,tail area,smooth grade of tail boundary,the relative symmetry degree of the molten pool vision image.3.Relation between Defects and Molten Pool Visual ImageBased on the molten pool image shape,boundary and scum characteristics, the molten pool image characteristics before occurring such defects as porosity,slag inclusion is researched for the first time.The main characteristics are as follows:the molten pool boundary showing as serration, some black flecks appearing at the molten pool tail,more scum,grey average value fluctuating and grey standard deviation becoming large.Those above characteristics may appear solely or several ones appear synchronously. Besides if those image characteristics appear,although it is not sure to bring porosity or slag inclusion,the probability of it will increase in great extent.4.Quality Intelligent Control Based on Visual SensingBased on fuzzy neuron net intelligent control technology,a fuzzy neuron net control model of weld width,penetration with spray,short circuit process based on visual sensing is also established.A further study on the experiments including disturbing factors is made and the corresponding model is corrected with experimental results.Results show that theestablished system has good effect on controlling the weld width.For the process which copper dePosited welding in TIG(plasma)arc,the quality auto-control method based on visual sensing is obtained;Some experiments including microstructure,electro microscope energy spectrum, high resolution transmission,mechanical performance testing are made.Results show that the eopper-steelboundary welding without penetration is obtained,the combination achieves atom grade and innovated results are obtained.5.Seam Molten Pool Double-Sight Visual Sensing TechnologyBased on the research of laser seam tracking,the laser vision seam geometry parameters sensing and tracking technology is developed.A structured laser double-sight visual sensing system is designed and studied.It.realizes the matching of Corresponding point in stereo-vision. The image Coordinate of seam characteristic point on two-dimension and geometry characteristics information such as groove type,angel,clearance are acquired.Using three-dimensional rebuilding arithmetic the three-dimensional coordinate can be calculated and the accurate three-dimensional geometry parameter of seams such as V、Half-V、butt-I、U and lap joint are acquired.6.Welding Procedure Auto-design System Software of Heavy Vehicle Gas Shielded Arc Welding RobotFor vehicle welding procedure intelligent design,a welding procedure auto-design system software of gas shielded arc welding(PMIG、MIG、MAG and SMAW)is presented and developed.The difficulty of double deducing based on the rules and experimental report welding procedure card,the Structured and semi-structured welding products information expressing and managing, information exchanging of welding CAD and proceduresystem figure is resolved. It also realizes the auto-resolving of the procedure with multi parameters and multi rules restriction in deducing process and batch procession output of products’ welding procedure.The software and hardware of real time sensing,issuing and remote transmitting of welding parameter for arc welding robot is designed and developed at thesame time.It realizes thesensing and cybernation transmission of welding current,arc voltage,welding speed and the moltenpool visual image.更多还原