共查询到19条相似文献,搜索用时 203 毫秒
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研究开发了一种具有4个发射光源和1个CCD摄像机作为接收装置的光学非接触测头.测头可以用来测量包括具有强反射表面的曲面.测头基于三角法工作原理.在恰当设计的情况下,至多只有1路从工件表面反射回来的光,能够进入CCD摄像机.通过将相应通道切断,很容易消除镜面反射光的影响.这时测头就相当于1个三发射单接收光学非接触测头.测头可以同时用来测量表面的位置和方向.对于具有很大倾斜的表面具测头仍能正常工作,采用干涉滤光片消除了环境光的影响.提出了一种系统的标定方法.通过对量块的测量证实了系统工作的正确性和有效性并给出了实验结果. 相似文献
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激光传感器在测量自由曲面中有着非接触、精度高等优点,其应用越来越广泛. 但是激光测头的线性测量
范围较小,难以测量起伏变化较大的曲面. 针对这一问题,提出了激光测头的跟踪测量方法,使激光测头随曲面的
高度变化作上下调整,从而可以测量任一表面起伏的曲面,且能根据当前曲面的曲率大小自适应选择跟踪方式,实
现测点的自适应分布.最后,对一个工件分别进行了等间距测量和自适应跟踪测量,并对两种方法的测量结果做了
比较,证明了自适应跟踪测量方法的可行性和有效性,为自由曲面的测量提供了一种新的方法. 相似文献
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光笔式单摄像机三维坐标视觉测量系统 总被引:5,自引:1,他引:4
提出了一种光笔式单摄像机三维坐标视觉测量系统,系统主要由一支光笔、一架摄像机、一台笔记本电脑组成.光笔是一种手持式触发测头,在笔休上装有三个与球形笔尖测头中心成一条直线的点光源(发光二极管).测量时使笔尖测头接触被测物体表面,摄像机摄取笔体上三个发光二极管的像,由三个发光二极管的像面坐标就可计算出被测点的三维坐标.运用三点透视原理(P3P)建立了系统的数学模型并推导出了被测点坐标的求解公式.在三坐标测量机上做对比实验,实验测试结果表明,该系统达到了大尺寸现场测量要求的精度. 相似文献
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针对激光加工的特定工艺要求,在对空间自由曲面测量系统分析的基础上,论述了测量系统研究的实际意义,进行了总体方案设计研究。内容包括:测头选择,系统控制方案设计,测试方案设计,数据处理方案设计等. 相似文献
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基于半球形测头的自由曲面截形测量方法 总被引:4,自引:0,他引:4
提出的半球形测头测量自由曲面任意截形方法避开了用球形测头测量曲面的复杂过程和由此产生的三维测头半径补偿的数学模型及大量运算,消除了在三维曲面截形测量时由于被测曲面的扭曲对测头所造成的干涉,可使曲面测量直接转化为曲线测量,从而大大简化了测量和数据处理过程。 相似文献
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应用光学测头的测量方式中,由于方便测量和易于随时测量,手掌和手指经常被选作测量部位.然而,由于人体不同部位皮肤结构的变异性,由人为运动导致的测量位置改变会对被测光有很大影响.为此,开发了一种基于掌/指纹图像匹配技术的有效方法,以避免测量位置的改变.该方法通过应用小波变换、相位相关和曲面拟合技术,分析不同测量位置之间旋转和平移改变量,然后驱动光学测头到达相应的位置,从而使光学测头每次均测量同一位置.其精度评测结果表明,平移检测精度达到1/50像素,旋转检测精度达到0.15°.光谱测量结果表明,该技术的应用使光谱稳定性提高了3倍左右. 相似文献
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运用半光斑成像原理设计了一种用于三坐标测量机的多功能激光瞄准测头。详细介绍了测头的光学系统工作原理和设计思路,采用自适应控制方法实时调节激光光强使其可以适应不同光学特性表面的瞄准测量,并进行了多功能测头的重复性瞄准测量、灵敏度测量、倾角跟踪实验。实验结果表明,该测头重复性瞄准测量不确定度优于1 μm,测量灵敏度可达30 mV/μm,激光跟踪瞄准被测曲面倾角可达25°,能满足三坐标测量机的使用要求。该测头具有检测速度快、自动化程度高、瞄准精度高的特点,结合三坐标测量机或者其它测长仪器,能够实现对自由曲面进行快速精确瞄准及轮廓图像瞄准测量,具有广泛的应用前景和实用价值。 相似文献
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The objective of this paper is to develop a flexible three-dimensional inspection system for sculptured surfaces by employing 'Coordinate Measuring Machine (CMM), CAD database and vision system technology. New surface identification and rough localization methods are suggested using a concept called ‘Z-layers’ and a vision guided system. The Z-layers are generated from a CAD database which classifies the three-dimensional models. The three-dimensional models are reconstructed using a vision system that identifies the model and roughly identifies the orientation and location of the object implementing Z-layers. Then inspection planning and fine localization methods are mapped out which are based on the CAD database. The experimental results indicate that the developed inspection system, with the proposed algorithm, can be implemented in modern industry to reduce measurement errors and increase productivity. 相似文献
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现有的法矢量测量技术无法满足测量准确度和实时性的双重要求,法矢量计算方法不能适用于不同曲率的曲面。利用双目立体视觉,本文提出了一种基于曲率自适应的法矢量测量方法。首先,在双目立体视觉的基础上,基于变曲率曲面特征建立制孔区域曲面模型,提出投影点的布局方法;然后,基于三维重建的投影点数据,提出了基于曲面曲率自适应识别的法矢量计算方法;最后,针对小曲率曲面样件的测量结果,与三坐标测量仪测得的法矢量进行对比,用以验证本双目视觉测量方法的精度。实验结果表明:该方法测量法矢量误差为1.6°。该方法可有效提高法矢量测量的准确度,满足大型航空零件现场测量的工程要求。 相似文献
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One major research issue associated with 3D perception by robotic systems is the creation of efficient sensor systems that can generate dense range maps reliably. A visual sensor system for robotic applications is developed that is inherently equipped with two types of sensor, an active trinocular vision and a passive stereo vision. Unlike in conventional active vision systems that use a large number of images with variations of projected patterns for dense range map acquisition or from conventional passive vision systems that work well on specific environments with sufficient feature information, a cooperative bidirectional sensor fusion method for this visual sensor system enables us to acquire a reliable dense range map using active and passive information simultaneously. The fusion algorithms are composed of two parts, one in which the passive stereo vision helps active vision and the other in which the active trinocular vision helps the passive one. The first part matches the laser patterns in stereo laser images with the help of intensity images; the second part utilizes an information fusion technique using the dynamic programming method in which image regions between laser patterns are matched pixel-by-pixel with help of the fusion results obtained in the first part. To determine how the proposed sensor system and fusion algorithms can work in real applications, the sensor system is implemented on a robotic system, and the proposed algorithms are applied. A series of experimental tests is performed for a variety of configurations of robot and environments. The performance of the sensor system is discussed in detail. 相似文献
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为实现准确的三维场景匹配,提出了一种基于边缘线的三目立体匹配方法.Canny边缘是一种常用的视觉特征,通过对Canny算子加以改进,提高了边缘线条匹配的可靠性.匹配过程分层次进行,首先通过边缘上少量点的成功匹配确定边缘线条间的对应关系,然后以此来约束该边缘上其他点的匹配.详细介绍了对应特征匹配所用的约束条件.首先,使用三目系统中第三个摄像机提供的额外极线约束,有效地减少了误匹配.由于常规所用的三目极线约束条件给出的匹配效果并不理想,提出了另外一种更加有效的三目极线约束应用方法.此外还介绍了边缘点的梯度方向约束,给出了基于以上约束条件的边缘线匹配算法.实验结果表明,该算法具有较高的匹配正确率,是一种有效的立体匹配算法. 相似文献
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Displacement measurement of moving objects is one of the most important issues in the field of computer vision. This paper introduces a new binocular vision system (BVS) based on micro-electro-mechanical system (MEMS) technology. The eyes of the system are two microlenses fabricated on a substrate by MEMS technology. The imaging results of two microlenses are collected by one complementary metal–oxide–semiconductor (CMOS) array. An algorithm is developed for computing the displacement. Experimental results show that as long as the object is moving in two-dimensional (2D) space, the system can effectively estimate the 2D displacement without camera calibration. It is also shown that the average error of the displacement measurement is about 3.5% at different object distances ranging from 10?cm to 35?cm. Because of its low cost, small size and simple setting, this new method is particularly suitable for 2D displacement measurement applications such as vision-based electronics assembly and biomedical cell culture. 相似文献
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目的为了进一步提高SLAM定位精度和小障碍物识别能力。方法采用SLAM与多目视觉结合的方法,首先构建AGV运动学模型,然后构建双目立体视觉模型,基于SURF+RANSAC改进的分区域加权算法,尽可能剔除冗余误匹配对,显著提高匹配精度。其次,在传统SLAM导航基础上融入单目视觉,实现关键工位点精确定位停靠,并给出二维码遮挡缺损情况下的解决方法,采用双目视觉实现距离实时测量。结果双目距离检测精度可达±1.88 mm,轨迹精度可以控制在±2 mm。结论融合SLAM和多目视觉可以有效提高导航定位精度和小障碍物识别能力,提高了SLAM的应用领域,具有一定的推广前景。 相似文献
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The reverse engineering approach is being widely applied in designing and manufacturing of sculptured surfaces. The first step in the reverse engineering process is collection of data lying on the surface. When using a coordinate measuring machine (CMM) with a touch trigger probe for digitizing data points, the probe radius must be compensated according to normal vectors. Previous works were addressed on the iterative measurement procedure to reduce the error caused by the compensation. The major problem of iterative methods is time consumption in digitization. This paper proposes a new architecture based on look-up table that keeps the estimated normal vectors of the measurement data to refine the data points digitized by CMM. The digitized data are first fitted into several NURBS curves by interpolation. The skinning method is then applied to interpolate these curves. Thus a smooth NURBS surface can be constructed and more accurate normal vectors of the measurement points can be obtained to compensate for the probe radius. By using this software iterative technique, we need only one digitization procedure. Therefore, much time can be saved and the efficiency of reverse engineering can be improved. 相似文献