共查询到19条相似文献,搜索用时 203 毫秒
1.
2.
本文提出了一种求解摄像机内参数的线性方法。首先通过空间平面上等边三角形的边计算灭点坐标,根据摄影变换的交比不变性,由拉盖尔定理及三角形的两边夹角计算出圆环点坐标。图像圆环点坐标方程构成内参数约束方程,从而计算出所有内参数。实验结果表明,该方法有较好的灵活性和较高的鲁棒性。 相似文献
3.
根据三点决定一个平面的原理,通过在盾构机中体上布置测量控制点,对其三维坐标进行测量;根据空间解析几何原理,推导出盾构机刀盘中心三维坐标以及俯仰角、横摆角、扭转角的计算方法。文章利用计算机的伪随机函数对盾构机姿态参数的测量精度进行了模拟评价,探讨了提高测量精度的方法。结果表明,盾构姿态参数的测量误差均服从正态分析;采用精度为3mm的激光经纬仪测量控制点坐标,得到的盾构姿态参数的误差范围比规范要求小得多。 相似文献
4.
在一个新的项目要开工之前,全线要进行一下对已交桩的GPS(Global Position System)点进行复测,复测时尽量用GPS仪器重新进行全线的平面控制,核实一下交桩的GPS点是否满足施工精度要求。如为了节省前期复测时间,直接用全站进行线路闭合测量,如果测量的闭合差满足施工要求;同时,也可以认为业主所交桩的点是可以使用。但因为种种原因,如点埋设的时间较长、一致,使点发生沉降和平移、GPS点的坐标给错、或现场的GPS点丢失或点被损坏,这样会导致测量的结果与交桩所给的坐标存在一些误差甚至一些点的坐标不正确,为了使项目测量工作能顺利进行和对施工控制点坐标进行合理的修正。我们有必要用GPS仪器对交桩点进行重新测量,也可以顺便加密一下原来交桩GPS点平面控制网,并且能重新补上被损坏和丢失的GPS点。在国外进行GPS点测量后的想法和见解,希望能给相关测量人员提供一些帮助,也请有测量经验的人提出一些修改意见。 相似文献
5.
6.
《价值工程》2013,(22):258-259
为了解决传统摄像机标定方法的精确度差和使用不方便,本文提出了一种基于主动视觉的摄像机线性自标定方法,该方法通过控制摄像机做一次纯轴向运动来确定主点坐标,再做一次纯旋转运动利用单应性矩阵与旋转矩阵的关系确定摄像机的其他三个内参数。这种基于主动视觉的自标定方法原理简单、实现方便、可操作性强。实验结果表明,该方法能够比较准确地标定出摄像机的所有内参数。摄像机标定是计算机视觉中的一项基本任务。传统的标定方法是通过结构的物体(如标定块,标定板等)在图像中的投影计算摄像机的内参数。但是这种方法必须要有标定物,在很多实际应用中难以实现。为了解决传统摄像机标定方法的精确度差和使用不方便, 相似文献
7.
8.
9.
张超群 《中国高新技术企业评价》2013,(8)
卧式加工中心工件平面校正,找工件孔心或外圆圆心建立XY零点,通常方法比较费时,如运用雷尼绍测头校正工件平面和寻找孔心,可以实现工件自动找正、自动建立坐标零点,省去人工找正的繁杂,免去人为误差,大幅提高了找正的效率。其方法主要是利用红外测头测碰采点,并根据测碰点的机械坐标数据进行计算,得出工作台偏转角度和各轴零点位置,最后写入零点偏置表而实现零点设置。 相似文献
10.
11.
针对计算机视觉摄像机镜头畸变对精度的影响问题,提出了一种非线性摄像机标定方法。该方法是将非线性模型视为线性模型和畸变项的叠加,然后在主动视觉下利用线性模型下的正交运动的FOE(当物体或摄像机做纯平移运动时图像对应点连线的交点)点的关系,给出非线性模型参数的约束方程,从而实现非线性模型的摄像机自标定。模拟和真实图像实验均表明,该方法是有效的,具有一定的实用价值。 相似文献
12.
This paper is concerned with the study of a circular random distribution called geodesic normal distribution recently proposed for general manifolds. This distribution, parameterized by two real numbers associated to some specific location and dispersion concepts, looks like a standard Gaussian on the real line except that the support of this variable is [0, 2π) and that the Euclidean distance is replaced by the geodesic distance on the circle. Some properties are studied and comparisons with the von Mises distribution in terms of intrinsic and extrinsic means and variances are provided. Finally, the problem of estimating the parameters through the maximum likelihood method is investigated and illustrated with some simulations. 相似文献
13.
N. Chernov 《Metrika》2011,73(3):373-384
We study a nonlinear regression problem of fitting a circle (or a circular arc) to scattered data. We prove that under any
standard assumptions on the statistical distribution of errors that are commonly adopted in the literature, the orthogonal
regression estimators of the circle center and radius have infinite (absolute) moments. We also discuss methodological implications
of this fact. 相似文献
14.
Due to the physical nature of certain periodic data, the harmonic dial points (the Fourier coefficients obtained from harmonic analysis of the data) are sometimes restricted to circular regions in the dial plane. It is proposed that a circular normal distribution (CND) truncated outside a circular region be used to describe the probabilistic behavior of the random phenomena. Recurrence relations for the population moments of a CND truncated outside a circular region are derived. These recurrence relations are used to obtain consistent asymptotically (jointly) normal estimators of the unknown parameters of the distribution. A numerical example based on the harmonic dial points representing the 27-day recurrence tendency of the daily international magnetic character-figureC
i
is given to illustrate the theory. 相似文献
15.
Christine H. Müller 《Metrika》2011,74(2):135-165
This paper studies tangential and simplicial data depth for simple orthogonal regression. Given N points in the plane, simple
orthogonal regression means that we wish to determine the line through the origin that has smallest distance to the points
measured in the direction orthogonal to the line. For both depth notions, it is proved that two lines which are orthogonal
to each other, i.e. two lines forming a cross, have the same depth. Depth-based orthogonal regression can thus merely fit
crosses, not lines. We investigated the robustness properties of maximum depth estimators using the notion of exact fit. Another
topic the paper covers is the testing of the hypothesis that the data points form a cross-like pattern. After a simple transformation,
such a test can be based on the biggest data depth. The paper discusses an application of this test for the investigation
of stress fractures in materials. 相似文献
16.
本文运用案例研究方法,以神华集团为研究对象,指出以企业集团为载体推动循环经济产业化发展是继以单个企业为载体的清洁生产路径,以多个彼此产权独立企业为载体的工业生态园、绿色供应链等路径之后,中国循环经济产业化发展的又一条新路径。企业集团是中国实施循环经济产业化发展的较好载体,首先通过企业集团的产权关系纽带可以建立稳定的循环... 相似文献
17.
A.W. Hoogendoorn 《Statistica Neerlandica》1992,46(4):259-282
In Wicksell's corpuscle problem one is interested in estimating the distribution of sphere diameters from the diameters of circle profiles obtained by a random section of the body containing the sphericle particles. The problem is known to be an ill posed inverse problem. Several regularization techniques have been applied to find solutions. We will review some of these in this article. In practical situations one often is more interested in the distribution of weight rather than the distribution of diameters. In estimating the weight undersite distribution similar problems are encountered. We will consider an estimator that is obtained by smoothing the distribution function of the circle diameters locally. It will be shown how the bandwidth must be chosen to obtain consistency and mean square error optirnality. Also asymptotic normality will be shown. 相似文献
18.
19.
Summary Nearest neighbour methods traditionally used to estimate density of a sessile biological population treat individuals as points.
The present paper suggests distance-based density estimators which treat individuals as circles with variable areas. Distribution
of distance between a sample point and thek-th (k = 1, 2, 3, …) nearest circle is derived. Maximum likelihood estimator of density is obtained from a random sample of point
tok-th order distances. Assuming a skewed distribution for the circle radius, moment estimators of density and mean circle area
are derived. 相似文献