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针对航空发动机叶片缺陷检测过程中,扇形段叶片间隙狭小且表面缺陷尺度小、形态差异大,位置隐蔽,常规测量方法无法实现检测的问题,基于改进的结构光测量原理,通过压缩光路空间体积,设计了微型线结构光视觉传感器。搭建了航空发动机扇形段叶片表面缺陷测量系统,设计了六轴联动控制结构,通过运动分解简化了机械控制结构,避免了由于插补控制引入的非线性运动误差。实验证明系统具有较高精度,实现了航空发动机扇形段叶片表面缺陷高精度测量。 相似文献
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《机械工程与自动化》2017,(5)
为实现对墙地砖表面缺陷快速精确的自动检测,对基于机器视觉的自动检测技术进行了研究,介绍并开发了一种基于机器视觉的墙地砖表面缺陷自动检测系统。在分析了墙地砖的表面特征、缺陷类型和现有检测算法的基础上,提出了一种基于图像梯度方差和加权信息熵相结合的自适应BHPF滤波检测算法。实验结果表明:该检测算法可快速有效地完成墙地砖表面缺陷的检测,缺陷识别正确率达97.3%。实验验证了理论分析和检测算法的正确性,可用于墙地砖表面缺陷的识别检测。 相似文献
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滑动轴承生产过程中,有少量滑动轴承因内表面会产生划痕、凹坑、凸点、涂覆层剥落等成为废品,出厂前必须将这些废品识别并剔除。目前检验这些缺陷的方法主要为人工目测,效率低,缺乏准确性和规范化。文中介绍一种基于机器视觉的滑动轴承内表面缺陷自动检测系统,该系统应用机器视觉技术,结合被测工件自动给料、定轴回转、自动剔除等装置,对滑动轴承的内表面缺陷、尺寸等多个参数实现高速自动检测,可以提高检测精度,节约劳动力。该自动检测系统可以实现滑动轴承内外径尺寸测量、内表面缺陷检测以及轴承型号判别等多指标高度动态检测,无需装夹,检测速度高达120~180个/min,满足滑动轴承大批量生产的要求。 相似文献
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为提高对细长产品表面缺陷的检测效率,运用机器视觉技术对细长产品外部轮廓尺寸及表面缺陷状况进行检测.运用机器视觉技术,分析图像传输过程中噪声产生原因及降噪方法;采用canny算法和Simple Blob Dectorte特征点检测方法,提取零件轮廓和色斑轮廓;编写基于机器视觉的表面缺陷检测程序,并通过实验验证了该方法的可行性.采用系统法对表面缺陷检测设备进行整体分析,设计出与检测程序相配套的机械设备. 相似文献
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针对金属管器件的表面缺陷检测进行研究,以机器视觉技术为基础,设计了金属管器件表面缺陷在线检测系统。根据生产线的实际检测要求,提出了检测系统的整体设计方案。针对金属管器件图像特点,设计了简单有效的图像处理算法。首先,提出了基于颜色统计特性的目标分割算法,实现了目标与背景的准确分割。然后,提出的实时光照校正算法,克服了光照影响,实现固定阈值的缺陷分割。最后,使用方向投影的方法定位缺陷区域,并采用面积指标对缺陷进行有效判定。实验结果表明,该方法对于每个器件的平均检测时间为0.21秒,缺陷产品的检测率为100%,能够满足金属管器件表面质量实时检测的要求。 相似文献
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G. Senthil Kumar U. Natarajan S. S. Ananthan 《The International Journal of Advanced Manufacturing Technology》2012,61(9-12):923-933
The variety of vision inspection systems for welding defects in the present manufacturing scenario is needed for overcoming certain limitations such as the problem of inaccuracy in the images, non-uniformed illumination, noise and deficient contrast, and confusion in defects if they occur in the same spot at the surface and subsurface. Hence, it is imperative to design a new vision inspection system which will enable to overcome the aforementioned problems in welding. A sophisticated new vision inspection system using machine vision has been developed for this study to identify and classify the surface defects of butt joint as per standard EN25817 in metal inert gas (MIG) welding. In this proposed vision system, images of welding surfaces are captured through a CCD camera. Four frames of sequence of images are obtained using four zones of LEDs using the front light illumination system in this method. From these images, the regions of interest are segmented and the average gray levels of the characteristic features of these images are calculated. The same process can be extended further to four zones (four quadrants) of four types of welded joints. Finally, welded joints can be classified into one of the four predefined ones based on the back-propagation neural network. The proposed system demonstrates an overall accuracy of 95% from the 80 real samples tested. 相似文献
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H. H. Shahabi M. M. Ratnam 《The International Journal of Advanced Manufacturing Technology》2009,40(11-12):1148-1157
Tool wear has been extensively studied in the past due to its effect on the surface quality of the finished product. Vision-based systems using a CCD camera are increasingly being used for measurement of tool wear due to their numerous advantages compared to indirect methods. Most research into tool wear monitoring using vision systems focusses on off-line measurement of wear. The effect of wear on surface roughness of the workpiece is also studied by measuring the roughness off-line using mechanical stylus methods. In this work, a vision system using a CCD camera and backlight was developed to measure the surface roughness of the turned part without removing it from the machine in-between cutting processes, i.e. in-cycle. An algorithm developed in previous work was used to automatically correct tool misalignment using the images and measure the nose wear area. The surface roughness of turned parts measured using the machine vision system was verified using the mechanical stylus method. The nose wear was measured for different feed rates and its effect on the surface roughness of the turned part was studied. The results showed that surface roughness initially decreased as the machining time of the tool increased due to increasing nose wear and then increased when notch wear occurred. 相似文献
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设计了一种新型的电机换向片自动检测系统,该系统通过CCD图像传感器采集电机换向片图像,在VC平台中嵌入Matlab,利用其Image Processing Toolbox对图像进行变换处理与特征识别,实现计算机视觉代替人类视觉驱使数控机械工作。实验表明该系统精度高、实时性强,具有一定的实用价值。 相似文献
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Development of a real-time laser-based machine vision system to monitor and control welding processes 总被引:2,自引:2,他引:0
Wei Huang Radovan Kovacevic 《The International Journal of Advanced Manufacturing Technology》2012,63(1-4):235-248
In this study, a laser-based machine vision system is developed and implemented to monitor and control welding processes. The system consists of three main modules: a laser-based vision sensor module, an image processing module, and a multi-axis motion control module. The laser-based vision sensor is designed and fabricated based on the principle of laser triangulation. By developing and implementing a new image processing algorithm on the platform of LabVIEW, the image processing module is capable of processing the images captured by the vision sensor, identifying the different types of weld joints, and detecting the feature points. Based on the detected feature points, the position information and geometrical features of the weld joint such as its depth, width, plates mismatch, and cross-sectional area can be obtained and monitored in real time. Meanwhile, by feeding these data into the multi-axis motion control module, a non-contact seam tracking is achieved by adaptively adjusting the position of the welding torch with respect to the depth and width variations of the weld joint. A 3D profile of the weld joint is also obtained in real time for the purposes of in-process weld joint monitoring and post-weld quality inspection. The results indicate that the developed laser-based machine vision system can be well suited for the measurement of weld joint geometrical features, seam tracking, and 3D profiling. 相似文献
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采用机器视觉来检测驾驶员眼睛状态对判别驾驶员疲劳具有重要意义,现有机器视觉采集系统中眼睛状态识别常用虹膜特征来衡量,针对虹膜信息缺失或者改变都会导致眼睛状态误检且准确性和实时性不能兼顾的问题,在分析机器视觉系统和人眼状态的基础上,以兼顾识别算法的实时性和准确性为目标,利用机器视觉系统成像带来的更好区分眼睛状态的非虹膜特征,提出了基于融合模型的改进型人眼状态识别方法,进一步搭建了嵌入式平台并进行了算法识别的对比实验。结果表明非虹膜特征的融合检测算法提高了人眼的睁闭眼识别的区分度,与模板匹配法相比,眼睛状态识别的准确性提高15%,耗时也减少了约1/3。 相似文献
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螺旋锥齿轮大轮齿形误差的在机测量 总被引:5,自引:1,他引:4
为了在国产数控螺旋锥齿轮磨齿机上实现大轮齿形误差的在机测量,对大轮齿形误差的在机测量方法进行了研究。基于齿轮坐标系与机床坐标系之间的关系,建立了将齿面离散点坐标及法矢从齿轮坐标系转换到机床坐标系的方法。根据大轮的齿面几何特征,建立了大轮齿形误差的在机测量方法以及测量流程。根据在机测量得到的测球球心空间坐标,运用曲面拟合技术和最优化算法,计算了实际齿面相对于理论齿面沿各离散点法矢方向的齿形误差值。通过对比在机测量和齿轮测量中心的齿形误差测量结果,验证了螺旋锥齿轮大轮齿形误差在机测量方法的正确性。 相似文献
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