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论文介绍了一种利用圆环形滚轮测头测量复杂曲面的新技术,提出了反求曲面廓形数据点的测量原理。应用此原理将测头中心点数据转化为实际接触点数据,可弥补球形测头断续接触式测量中的测量速度慢、效率低,非接触式激光测量中精度易受切削液等污物影响、设备成本高等多方面的不足。同时,也使一些回转曲面类零件实现了在线、在机及加工现场的快速测量。最后,通过数学验证证明了该测量理论的正确性。 相似文献
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传统的三维扫描方法通常对被测曲面进行一次测量,但在被测曲面的形貌和范围未知的情况下,扫描数据不完整、结果不准确且无法进行有效评价。提出的基于动态路径规划的三维扫描方法主要通过对被测曲面进行粗扫掠和二次扫描,针对三维信息缺失区域自动对扫描路径进行合理规划,引入最小包容球理论和可视锥概念,为三维扫描样品的采样点规划、扫描仪视点和扫描方向生成提供理论依据。该基于动态路径规划的三维扫描方法的可行性在对实际被测曲面的扫描实验中进行了验证并对其扫描质量进行了评价。 相似文献
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《组合机床与自动化加工技术》2019,(5)
针对当前应用于数控加工在机检测领域的接触式传感器标定效率低、成本高等问题,提出了一种面向加工中心在机检测的接触式传感器标定方法。该方法将数控加工与检测技术相结合,首先在分析加工中心在机接触式检测的基础上,通过建立传感器标定数学模型确定了标定参数;其次,通过对标准球的触测,基于最小二乘法拟合计算得到接触式测头的标定参数,最后通过标定实验和对标准件的接触式检测精度分析验证了该方法的可行性和有效性,可在机接触式检测提供一种新的传感器标定方法。 相似文献
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探索运用逆向工程来构建三维曲面网状冲压件的三维数学模型。该方法使用激光三坐标扫描测量仪对三维曲面网状冲压件进行非接触式测量,得到三维曲面网状冲压件的点云数据,再运用Geomagic对点云完成数据拟合,得到三维曲面网状冲压件的数字化模型。相比于以三坐标测量机(CMM)为代表的传统测量网状冲压件三维坐标的接触式坐标测量方法存在的测量速度慢、测量精度不高的不足,激光三坐标扫描测量仪测量的速度更快,测量的精度更高。且Geomagic对点云完成数据拟合得到的数字化三维模型更贴合实际的模型,表明该方法切实可行。 相似文献
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为解决自由曲面CMM测量中测头半径补偿问题,沿用了基于测头中心点所在曲面法矢估算的空间补偿方法,引入转动惯量法进行测头中心点所在曲面各点处法矢的求解,并解决了边界点补偿的问题。该方法避免了根据离散点构建样条曲面而进行大量而复杂的计算过程,数据处理简单,并可通过程序实现,具有较高的效率。 相似文献
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面向自由曲面零件的在线检测技术研究现状 总被引:2,自引:0,他引:2
数控机床在线检测系统是集数控机床、测头及计算机等为一体的高度集成化系统.高精度在线检测是实现柔性制造系统连续可靠工作的重要手段,是保证数控机床加工精度和效率的重要措施.在航空、汽车、模具等现代工业生产中出现了越来越多的自由曲面零件,这对测量系统提出了更高的要求,因而对具有自由曲面的零件进行高精度高效率的检测将是当前的一个重要研究方向.本文主要介绍自由曲面零件的在线检测技术在国内外的研究现状与进展,包括检测系统开发、自由曲面零件的接触式测量及路径规划和误差补偿等3部分,指出了目前在该领域存在的有待于进一步解决的关键问题. 相似文献
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Towards a haptic virtual coordinate measuring machine 总被引:2,自引:0,他引:2
Y. H. Chen Y. Z. Wang Z. Y. Yang 《International Journal of Machine Tools and Manufacture》2004,44(10):1009-1017
In this paper, a novel coordinate measuring machine (CMM) inspection path planning environment, named haptic virtual coordinate measuring machine (HVCMM), is proposed, which makes use of haptic modeling technique for CMM off-line programming. HVCMM is an accurate model of real CMM, simulating a CMM’s operation and its measurement process in a virtual environment with haptic perception. It enables CMM off-line programming to take place exactly as if an operator were in front of a real CMM and moving a real CMM probe. To generate the inspection path of a part, teach pendant programming is made by pointing a probe at the 3D computer-aided design (CAD) model of a part using a haptic device. With the HVCMM system, it is much easier to generate collision-free probe path than using other off-line inspection planning methods. Furthermore, when a contact occurs between the CMM and the object, a force is generated based on a proposed mechanics model besides visually showing the contact in the HVCMM environment. Surface voxel is used for quick collision detection. The HVCMM not only facilitates the inspection path planning, but also speeds it up. The proposed HVCMM can also be used for the training of CMM operation. 相似文献
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This paper presents a system and methodology for on-line free form surface measurement via a scanning contact probe installed on a CNC (computer numerical control) machine. The scanning probe provides more sampling points than any traditional touch trigger type of probes used on CNC machines, and better measuring accuracy than laser displacement sensing or structured lighting. The presented measuring system's main advantage is that the number of measured points can vary with the change of surface curvature. To improve the measuring stability and continuity, fuzzy logic control, in lieu of traditional PID control, is employed. As a result, the system is capable of continuously detecting the boundaries of a measured object and measuring a relatively large complex surface. Based on the experimental results, the measuring accuracy is estimated between 20 and 30 μm (micrometers). In addition to surface measurement, the reconstructed surface data can be fed to a CAD/CAM system for component making or reproduction, which makes the reverse engineering of models comprised of free form surfaces readily accessible. 相似文献
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Application of eddy-current method for nondestructive determination of corrosion attack depth at aircraft wing skins A NDI test system for the determination of the depth of corrosion attack in the form of shallow pit formation and pitting is presented. The system is based on the eddy-current method, whereby the signals of a specially developed probe are converted to an image representation, which can he evaluated quantitatively at a PC-screen. The described test system was developed for the field of in-service inspection of aeroplanes. As a first practical operation, the system was tested in co-operation with Daimler-Benz Aerospace at TORNADO aeroplanes. All the described results can be transferred to other test situations with comparable damage mechanisms. Because of the Skin-effect of the eddy current, this method is limited to surface-near areas however. If the test object comes as metal sheets, depth evaluation of corrosion attack on the hidden surface is also possible (even in multi-layered structures). 相似文献
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精确测量空间自由曲面的传统方法是采用三坐标测量机的接触测量或简单的非接触测量,这些测量方法存在工作效率低,自动化程度低等缺点。在深入研究上述方法的基础上,提出了一种自由曲面的非接触自动测量方法,介绍了测量系统的构成,曲面边缘的提取,自动扫描方式的规划以及测头跟踪方式等设计要点。 相似文献
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气动微型机器人的研究 总被引:2,自引:0,他引:2
本文根据仿生学原理,研制了一种气动微型机器人,并阐述了该机器人的工作原理和相关的控制系统。由于此微型机器人通过充气膨胀的气囊与管道壁接触,有较高的柔软性和非破坏性,可用于细小管道的检测。 相似文献
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介绍了一种利用相控阵超声技术结合专用的Cobra扫查器,对小径管环焊缝进行检测的方法。该方法符合ASMEB31标准,是一种小径管射线检测的完全替代技术。通过试验和客户现场检测应用,该方法可对21~114mm小径管进行环焊缝检测,并可进入狭小空间进行检测。由于其曲面晶片的特性,其检测结果比线性晶片的检测精度更高。对碳钢和不锈钢都可进行检测。检测前可对检测进行模拟,检测后可对检测结果进行精确地分析。 相似文献
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基于弹性模型的三角网格曲面优化展开 总被引:1,自引:0,他引:1
根据材料力学中杆件的变形及弹性变形能分析,提出了曲面展开的弹性变形模型。根据边的变形情况,将曲面展开分为约束展开和无约束展开,并对每种展开方法进行分析。特别是约束展开时产生的变形能,根据曲面展开时的判断准则,对弹性变形能进行释放,得到优化的曲面展开。最后给出了曲面展开的算法步骤及实例。该方法中曲面展开的局部精度较易控制,因此较之以前的方法,更能有效地解决CAD/CAGD中曲面展开问题。 相似文献
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