共查询到19条相似文献,搜索用时 140 毫秒
1.
在激光拼焊中,背面焊缝成形质量直接影响焊件的机械性能.文中在分析结构光视觉检测原理的基础上,建立了基于结构光视觉传感的焊后焊缝背面质量检测系统并对焊缝背面质量检测系统图像处理方法进行了深入研究.在图像处理过程中,首先通过开窗处理来获得兴趣区域,采用中值滤波去除图像噪声;其次使用迭代自动阈值法分割出结构光;在结构光条纹中心线提取过程中,提出了一种新的模板法获得了条纹的边界并用几何中心法提取了条纹中心线;然后,将斜率分析法引入到条纹中心线特征点检测中并获得了中心线上的一系列特征点.最后通过背面焊缝的图像序列,计算获得了背面焊缝不同位置处的几何参数及缺陷值.试验表明,该焊缝背面质量检测系统图像处理方法可靠性高、运算速度快、抗干扰能力强,具有较高实用价值. 相似文献
2.
基于视觉的激光拼焊焊缝表面质量在线实时检测系统中,结构光条纹中心线能否快速、准确提取是影响检测系统性能的关键因素之一。传统的高斯拟合法和Hessian矩阵法虽然具有较高的亚像素提取精度,但其计算量非常大,无法满足实时性的要求。文中在分析激光拼焊焊缝质量检测系统中结构光条纹图像特点的基础上,将传统的几何中心法引入到结构光条纹中心线提取中,提出了一种精度介于像素级到亚像素级之间的局部阈值几何中心法。实验表明:该算法具有较高的精度和较强的抗干扰能力,实现了视觉检测系统中结构光条纹中心线的快速提取,为激光拼焊焊缝质量视觉检测系统在线实时检测奠定了基础。 相似文献
3.
在基于结构光视觉的激光拼焊焊缝表面质量检测系统中,需要准确获得焊缝结构光条纹中心线和特征点的位置.由于焊接过程中的各种噪声干扰,使得焊缝图像复杂多变,因此选择合理高效的图像处理算法是非常重要的.针对这一问题,对结构光视觉焊缝质量检测系统图像处理方法进行了深入研究.在图像预处理中,首先通过开窗处理来获得兴趣区域,采用中值滤波去除图像噪声.在结构光条纹中心线提取过程中,提出了一种新的模板法获得了条纹的边界并用几何中心法提取了条纹中心线;最后,使用斜率分析法提取了特征点.试验表明,该方法具有较高的特征点检测可靠性,并且运算速度快、抗干扰能力强,具有较高实用价值. 相似文献
4.
5.
6.
7.
针对结构光条纹曲率变化较大时中心线提取存在误差,导致焊后角焊缝外观参数检测不准确的问题,提出一种基于结构光的角焊缝外观检测算法。首先建立角焊缝外观检测系统并对系统内相机进行标定;然后采集图像并经过高斯滤波、Otsu值分割等一系列图像预处理,提出一种法向平均法来提取结构光条纹中心线;最后通过直线拟合法与移动向量法来提取结构光特征点,结合角焊缝外观定义计算出其宽度、凸度和咬边等外观参数。实验结果表明,所提出的角焊缝外观检测算法准确性高,平均误差为0.021mm,且系统算法具有良好的稳定性。 相似文献
8.
《机械设计与制造》2015,(8)
激光焊接是一种高质量、高速度、低变形的焊接方法,广泛应用于机械制造、航空航天、汽车生产、微电子等领域。为在进行薄板拼焊前获取焊缝轨迹,利用视觉系统焊接轨迹进行规划。使用了数控焊接机床,激光焊接头安装在数控机床的Z轴上,视觉检测系统安装在激光焊接头上。主要对焊缝检测系统中,CCD相机内参数和低功率激光器投影光平面标定方法进行了研究。相机内参数的标定使用了张氏标定法。投影光平面标定时,靶标放置在数控机床的X-Y平台上,低功率激光器投射结构光条纹在靶标上,视觉系统随Z轴移动并在三个位置拍摄靶标图像。在三个位置分别提取靶标上特征点及投影光条中心,应用交比不变性得到投影光条的空间坐标,拟合后可得到结构光平面。 相似文献
9.
10.
针对V型坡口中厚板对接焊焊缝特征点检测精度不高的问题,研究了一种基于激光视觉传感的角点检测与光流(LK)跟踪的焊缝特征快速提取与定位方法。根据三角测量原理,设计了能够实时检测焊缝特征图像的激光视觉传感器,并建立了由激光条纹特征点像素坐标到焊缝特征点三维坐标的数学模型;对焊缝图像进行了预处理,采用Shi-Tomasi角点检测提取了焊缝特征;最后使用光流法为后续帧匹配特征角点,实时计算出了图像中焊缝特征点的亚像素位置。研究结果表明:基于角点检测与光流法跟踪的焊缝特征提取与定位方法,其特征点检测精度较高,平均误差在±0.13 mm以内,可以实时、准确地识别焊缝特征。 相似文献
11.
激光拼焊板成形极限图性能分析 总被引:1,自引:0,他引:1
对汽车用冷轧钢板进行了等厚激光拼焊试验,并进行了成形极限图性能分析和将等厚激光拼焊板进行汽车零部件实冲试验。结果表明:尽管激光拼焊板激光焊缝部位由于焊缝的硬化其成形性能较母材有所降低,但通过激光焊缝位置的合理设计,激光焊缝的应变安全裕度能够满足汽车零部件的成形要求。 相似文献
12.
13.
为确保焊接过程中焊枪始终沿焊缝运动,提升焊接质量,采用基于主动视觉传感技术的新一代激光视觉传感器实时采集焊缝轮廓的图像,由传感器控制柜按在PC界面上选定的算法进行图像处理与特征识别,提取焊缝跟踪点的位置坐标,并根据标定的参考位置和预设的比例关系转化为模拟电压量输出,进而驱动十字滑台上的伺服电机带动焊枪做出相应的纠偏动作。可编程逻辑控制器(PLC)被用来实现焊枪初始定位、滑台的手动控制与自动跟踪模式切换、安全互锁等功能。最终建立了一套适用于焊接专机的焊缝自动跟踪应用系统。实验结果表明,该系统安全实用,具备了良好的实时跟踪能力。 相似文献
14.
随着焊接过程自动化和智能化的发展,基于图像处理技术的焊缝位置检测和焊接缺陷检测过程越来越受到国内外学者的重视。本文对焊缝自动跟踪系统中有关图像处理方面的内容作了分析。详细分析了图像处理技术在焊缝跟踪过程中的应用,其中包括图像预处理,边缘检测和特征点提取等图像处理过程;并对当前焊缝跟踪中的图像处理技术存在的问题和解决方法作了一些总结和分析,最后对其应用前景作了展望。 相似文献
15.
In this study, a visual sensor system for weld seam tracking the I-butt weld joints in GMA welding was constructed. The sensor
system consists of a CCD camera, a diode laser with a cylindrical lens and a band-pass-filter to overcome the degrading of
image due to spatters and arc light. In order to obtain the enhanced image, quantitative relationship between laser intensity
and iris opening was investigated. Throughout the repeated experiments, the shutter speed was set at 1/1000 second for minimizing
the effect of spatters on the image, and therefore the image without the spatter traces could be obtained. Region of interest
was defined from the entire image and gray level of the searched laser stripe was compared to that of weld line. The differences
between these gray levels lead to spot the position of weld joint using central difference method. The results showed that,
as long as weld line is within ±15° from the longitudinal straight line, the system constructed in this study could track
the weld line successfully. Since the processing time is no longer than 0.05 sec, it is expected that the developed method
could be adopted to high speed welding such as laser welding. 相似文献
16.
Markus Heber Martin Lenz Matthias Rüther Horst Bischof Hartwig Fronthaler Gerardus Croonen 《The International Journal of Advanced Manufacturing Technology》2013,65(9-12):1371-1382
Traditionally, automated quality inspection of welding tasks relies on nonvisual information and is mainly done off-line. In this work, we introduce an image acquisition system which is capable of monitoring the welding process on-line, resulting in high-quality image information during an ongoing welding process. We show how to further exploit this image information by automatically tracking the weld seam position in the image, even under heavy smoke and gas disturbances. We exploit the high information redundancy between subsequent frames given by large overlap to generate a seamless image of the entire weld seam and effectively suppress adverse optical effects caused by, e.g., smoke and sparks. 相似文献
17.
18.
Uğur Köklü 《The International Journal of Advanced Manufacturing Technology》2013,66(1-4):221-229
Tailor-welded blanks (TWBs) have been widely used in the automotive industry as they reduce car weight and manufacturing cost. A new deep drawing system with an antilock braking system (ABS) was used for the improvement formability of tailor-welded blanks. In this study, Al-1050 aluminum alloy sheets, having a thickness of 1.5 and 2 mm, were welded using both a metal inert gas (MIG) and a laser welding. The effect of the conventional and ABS methods on the limiting drawing ratio (LDR), punch force, weld line movement, and wall thickness is investigated. The experimental results showed that tailored blanks produced using laser welding are not suited for deep drawing. In contrast, however, the MIG-welded blanks are suitable for deep drawing. These TWBs were deep drawn with both the conventional and ABS methods. The ABS method improved the LDR from 2.06 to 2.15 and decreased the maximum load from 17.31 to 16.53 kN when compared with the conventional method. 相似文献
19.
Bernard Johan Aalderink B. Pathiraj R. G. K. M. Aarts 《The International Journal of Advanced Manufacturing Technology》2010,48(1-4):143-154
Laser welding has a large potential for the production of tailor welded blanks in the automotive industry, due to the low heat input and deep penetration. However, due to the small laser spot and melt pool, laser-based welding processes in general have a low tolerance for seam gaps. In this paper, five laser-based welding techniques are compared for their gap bridging capabilities: single-spot laser welding, twin-spot laser welding, single-spot laser welding with cold wire feeding, twin-spot laser welding with cold wire feeding and laser/GMA hybrid welding. Welding experiments were performed on 1.1- and 2.1-mm-thick AA5182 aluminium sheets. The resulting welds were evaluated using visual inspection, cross sectional analysis with optical microscopy, tensile tests and Erichsen Cupping tests. The results show that the use of a filler wire is indispensable to increase the gap tolerance. A proper alignment of this wire with the laser spot(s) is crucial. With the single spot laser welding with cold wire feeding, a gap up to 0.6 mm could be bridged as opposed to a maximum allowable gap width of 0.2 mm for single-spot laser welding without filler wire. For 2.1-mm-thick sheets, the laser/GMA hybrid welding process can bridge even gaps up to 1.0 mm. Most welds had a high tensile strength. However, during Erichsen Cupping tests, the deformation of the welds is significantly lower as compared to the base material. 相似文献