共查询到19条相似文献,搜索用时 203 毫秒
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针对汽车冲压件尺寸人工测量方式存在的检测效率低和测量精度难以保证等问题,提出了一种基于亚像素精度的尺寸测量方法。先对汽车冲压件进行图像采集和预处理,接着利用Canny算子和改进Zernike矩进行冲压件图像亚像素边缘提取,再通过Hough变换对提取的圆轮廓进行拟合,最终获得了冲压件外圆直径和3个内孔直径的精确尺寸,4个圆轮廓的测量精度均高于0.025 mm,且多次测量结果的标准差小于0.009 6 mm。基于亚像素精度的尺寸测量系统,完成了测量平台的搭建和软件系统的开发,实现了汽车冲压件尺寸的非接触式亚像素级精度测量,能够满足工业应用的快速连续性测量要求。 相似文献
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零件孔径视觉精确测量研究 总被引:1,自引:0,他引:1
建立了一种基于虚拟仪器技术的零件孔径视觉检测系统。系统选用背光源照明,采用非线性校准及查找圆边的方法对采集到的图像进行测量。文章提出并实现的基于LabVIEW初始检测参数自动优化方法,保证了系统的重复检测精度.经实验证明,系统可以快速地测量零件孔径,并且测量结果准确。 相似文献
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针对目前钢管端面壁厚的测量多采用人工抽检的方式,从而导致测量效率低、精度低、测量数据少的情况,对机器视觉测量技术进行了研究。基于机器视觉,设计钢管壁厚在线检测系统。通过对相机进行标定,获得图像像素值与实际值之间的关系,使用相机采集钢管端面图像,对采集得到的图像进行图像预处理、边缘特征点提取等操作;改进RHT圆检测算法,完成钢管端面圆形轮廓的检测,进而实现对钢管端面壁厚的测量。为了便于操作,基于Qt跨平台开发框架设计了钢管壁厚检测系统人机交互界面软件。结果表明:该系统具有良好的稳定性,检测误差约为0.1 mm,可以高效地完成壁厚检测任务。 相似文献
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在实际生产线上,根据不同的尺寸偏差对同一型号的轴承沟道曲率半径进行在线检测。针对该问题,设计基于机器视觉的轴承沟道曲率半径在线检测系统,以替代人工检测。运用CCD摄像机与MATLAB图像处理技术相结合的方法,对零件进行非接触式测量,并对采集到的零件图像进行预处理;通过对比各种边缘检测算法,采用Canny算法求取像素精度的轴承边缘;利用圆的Hough变换检测出带有圆弧的圆特征,计算此圆弧的圆心坐标和半径值。实验结果表明:该系统的测量精度可达到0.5μm,测量标准差小于2.5μm,符合工业检测要求。 相似文献
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鉴于视觉测量过程行为的多样性与影响关系的复杂性,提出基于行为自适应的台钻主轴视觉测量新策略。采用周向分工位采集图像与轴向分段提取轮廓结合的组合采样法获取被测信息,并建立了主轴轴径视觉测量系统;设计曝光自适应图像采集、图像批处理、误差反馈闭环测量等功能集成的行为自适应视觉测量流程并开发相应软件。以某型号台钻主轴为对象,开展曝光区间自适应优选实验,多工位、多轴、多采样方案测量实验误差分析与稳定性评定。结果表明:所提出的行为自适应测量策略通过获取测量行为变化对测量误差的影响,形成闭环测量,可有效提高测量的稳定性,不仅满足台钻主轴高精度轴段测量需求,还有利于推动测量智能化发展。 相似文献
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基于快速测量的曲面多点成形精度控制 总被引:2,自引:0,他引:2
在板类件多点成形中,由于板料回弹、工件定位等因素,成形后的工件曲面与目标模型之间存在误差。文章通过激光快速扫描测量获得成形后工件的三维形状点云数据,经平滑去噪后,用对异常点不敏感的鲁棒最小二乘法进行B样条曲面拟合。将重构的曲面与目标模型配准计算后将曲面误差反馈到多点CAD系统,根据该误差进行回弹补偿、闭环修正工件曲面误差,并给出应用实例。结果表明,基于快速测量的曲面多点成形精度控制技术充分利用了多点成形的快速性的特点,通过三维空间形状反馈,来提高多点成形的精度。 相似文献
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Displacement during welding provides important information to understand the mechanisms of welding deformation and residual stress. In particular, if welding deformation can be measured sequentially and the displacement distribution over full field can be measured such as the results obtained by finite element analysis, they can be valuable information. Therefore, in this study, a 3-dimensional (3D) deformation (in-plane and out-of-plane deformation) measurement method is developed using a digital camera, which requires no special equipment. This method is a non-contact method and it can sequentially measure over the entire photographed image. Furthermore, since image analysis is based on the technique of image matching, the method is applicable even when measuring deformation is large. In addition, since it is possible to use all pixels as measuring points, the number of available measuring points at one time is the same as the number of effective pixels of the camera. This is currently more than 15 million points, and the measuring precision is expected to increase as the camera pixel resolution continues to increase. Therefore, this method is expected to have future potential. In this study, the proposed method is applied to the sequential measurement of displacement under the strong lighting levels in arc welding. By comparing the time history of transverse shrinkage, longitudinal shrinkage and angular distortion with the results of FEM thermal elastic-plastic analysis, the qualitative validity of the proposed method is verified. To investigate the measurement precision and usefulness of the method, a 3D shape measurement system (LAT-3D) using a laser displacement gauge and digital caliper are used. The distributions of residual transverse shrinkage and residual angular distortion are measured by the proposed method, LAT-3D and digital caliper. Through the comparison of the results measured by these methods, quantitative validity of the proposed method is also verified. 相似文献
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采用数字图像分割和亚像素边缘检测等图像处理技术自动测量刀具磨损边界的磨损量并与刀具磨钝标准比较,判断刀具的磨损状态,实现刀具磨损状态的间歇式在线自动检测。针对刀具的边缘特征,运用了中值滤波、对比度拉伸、迭代自适应二值化、基于分水岭分割、Roberts边缘算子、图像匹配、Zernike正交矩边缘检测和曲线拟合等数字图像处理技术,完成了刀具磨损量微米级的高精度检测。 相似文献
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针对软胶囊实时缺陷检测与丸形分级问题,提出一种基于远心视觉的椭圆度测量方法及其系统。以最小二乘椭圆作为评定基准,用被测轮廓的最小外接椭圆和最大内接椭圆的通径定义椭圆度误差,建立了椭圆度评定的最小二乘数学模型;建立胶囊缺陷与丸形分级的远心视觉检测系统,给出胶囊缺陷与丸形分级的检测流程;以某药企的保健药丸为对象,开展胶囊缺陷与丸形分级的视觉检测实验。结果表明:合理设定阈值,丸形分级检测的准确率可达100%;单颗胶囊的检测用时0.712 s。通过开发并行处理算法,缩短耗时、提高效率,该椭圆度误差评定方法及远心视觉系统可用于胶囊缺陷与丸形分级的实时检测。 相似文献
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规则栅线投影到物体表面的变形光栅,采用单步相移算法解调出含有物体表面高度信息的位相,建立了一种较传统相称技术快速、但精度相当的投影技术,该技术只需采集一幅图象,给 个典型试件的实验结果和分析。 相似文献
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齿轮检测技术是检验齿轮生产和质检能力的有效手段之一,随着近些年对齿轮精度要求的不断提高,非接触式的齿轮参数测量方法被越来越多地应用到实际生产和质检环节中。提出一种利用机器视觉实现齿轮齿形参数测量的方法,实现非接触式齿轮齿形参数测量。此测量系统使用轮廓拟合法来测量齿轮齿形基本参数,使用事件结构编写程序,完成了基于视觉的齿轮齿形参数测量系统。利用USB摄像头,使用背光光源对齿轮进行照明,通过USB接口连接到计算机上,利用Lab VIEW图形化编程平台的IMAQ模块对采集到的齿轮图像进行分析处理;还加入了系统测量误差分析模块,能够实时计算并显示测量误差。实验结果表明:此系统运行稳定,可重复性良好,测量精度高。 相似文献
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On-line error compensation of coordinate measuring machines 总被引:1,自引:0,他引:1
An on-line error compensation system for coordinate measuring machines (CMMs) is described, which is based on three laser optical Multi-Degree-of-Freedom Measurement Systems (MDFM systems), each for one axis of CMMs. Twelve of the twenty-one error components associated with a CMM are measured on-line by these MDFM systems. The remaining error components are measured by off-line methods which use commercially available measurement systems, such as a laser interferometer. Two mathematical error models have been developed to synthesize the error components and to predict the errors at the probe stylus tip. One model corresponds to the conventional off-line error compensation and the other to the on-line error compensation. The errors predicted by these models are then subtracted from the nominal coordinates of the CMM, thus improving its measurement accuracy. Diagonal tests using a laser interferometer system were designed to check the error compensation effect. Test results showed that the use of the on-line compensation system can further improve the compensation effect as compared with the conventional off-line compensation system. 相似文献