共查询到19条相似文献,搜索用时 156 毫秒
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文章对坐标测量机的测量软件在几何量数值计算方法及误差评定方法方面的重要作用和德国国家物理技术研究院(PTB)采用被ISO 10360—6定为测量机软件标准算法的最小二乘法对测量软件测试的认证方法进行了简单介绍。为加深对坐标测量机的测量软件处理测量数据原理及评定几何误差方法的认识,使用GLOBAL ADVANTAGE 7107接触式坐标测量机对待测件进行几何误差测量并应用PC-DMIS测量软件进行误差评定。另一方面,从几何误差的定义、应用及公差带区域的形状出发,应用解析几何方法结合最小二乘法对几何误差项目中的直线度、圆度误差建立数学模型,而后代入测量点资料并给出迭代公式、初始解、迭代终止准则应用迭代法进行求解计算相应项目的误差值。最后将PC-DMIS软件误差评定结果与计算结果进行比较、分析。 相似文献
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采用最小区域圆法进行圆度误差评定时,圆度误差的最终评定结果取决于位于最小区域圆上的采样点的坐标,而与其它点无关。删除圆度误差测量中的这些无关点可有效降低圆度评定算法的计算复杂度。将计算几何中α-壳的概念应用于圆度误差评定过程中;提出了一种在保证评定结果正确的前提下圆度评定中无关点的删除准则和删除算法;实验证明,本文提出的方法可有效删除圆度评定过程中的无关点。 相似文献
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介绍了利用最大内接圆判别准则求解圆度误差的基本思想,论述了用最大内接圆法评定圆度误差值的快速、精确算法。利用本文所述的计算方法,能够设计出圆度误差评定软件,实现三坐标测量数据的圆度误差评定。 相似文献
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本文探讨了应用三坐标测量机测量圆度误差时其测量结果的不确定度的分析与评定。在做精密测量时,测量结果的准确性评价,国际上推荐使用测量不确定度作为度量尺度。为判定测量结果的准确性,有必要对圆度测量结果进行不确定度的评定。 相似文献
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基于区域搜索的圆度误差评定方法 总被引:2,自引:0,他引:2
针对最小二乘法评定圆度误差存在的非线性方程组求解困难、线性化处理后的最小二乘法对测量采样点的布置特殊要求难以满足等问题,提出了基于区域搜索的圆度误差评定方法,阐述了方法的原理与实现步骤,并进行了实际圆度误差的对比测量与评定.结果表明,此方法简便易行,评定精度比最小乘法提高4.16%. 相似文献
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Roundness inspection strategies for machine visions using non-linear programs and genetic algorithms
Mu-Chen Chen 《国际生产研究杂志》2013,51(13):2967-2988
This study proposes the inspection strategies of computational metrology for roundness measurement and roundness feasibility analysis with respect to ANSI Y14.5M-1994 standard. The roundness measurements are formulated as constrained non-linear programs, and optimization techniques are applied to locate the optimality. Through reformulating the geometric conditions and adding further constraints to the roundness measurement problems, the analysis of roundness inspection can be made by only investigating the feasibility of the constrained non-linear programs instead of advancing to the optimality. Two approaches of computational metrology based on genetic algorithms (GAs) are proposed to explore the optimality of roundness measurements and the roundness feasibility analysis, respectively. Finally, real data generated from machine visions and simulation data generated from analytical curves are used to test the proposed GA-based roundness assessment approaches. The experimental results indicate that the proposed algorithms are practical for on-line implementation to the roundness measurement and roundness feasibility analysis. Furthermore, the proposed computational strategy for the roundness feasibility analysis performs efficiently if the tolerance size is adequately specified and the process capability is stable. 相似文献
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Q. Huang J. Mei L. Yue R. Cheng L. Zhang C. Fang R. Li L. Chen 《Materialwissenschaft und Werkstofftechnik》2020,51(1):38-46
With the rapid development of micromachining technology, the feature size of object parts becomes smaller whilst the required tolerance accuracy becomes higher. The geometry of these micro-parts must be critically verified at sub-micrometer or even nanometer accuracy in three dimensions to guarantee machining quality, such as the cylindrical parts. Therefore, the method for estimating roundness error plays an increasingly important role in machining. This paper focuses on the roundness estimation based on the minimum zone circle method in a Cartesian coordinate system. An asymptotic search method is also proposed to obtain the coordinates of the concentric centre of the minimum zone circle model and to calculate the roundness error. Comparison and simulation experiments are also conducted to test the performance of the proposed method. The results demonstrate that the proposed method is effective, reliable and can meet the requirements for roundness estimation. 相似文献
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The effect of centering accuracy on the error for measurement of roundness deviation is considered. A method is proposed for
processing the results of measurements based on harmonic analysis, compensating for a given error. Results are given for comparative
analysis by the well-known and suggested methods in measuring deviation from roundness on the basis of Monte-Carlo statistical
modelling.
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Translated from Izmeritel’naya Tekhnika, No. 11, pp. 20–22, November, 2006. 相似文献
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计算几何评定国度的方法研究 总被引:2,自引:0,他引:2
和传统方法相比,计算几何方法评定圆度误差几何直观性强、结果准确,而又能解决同时存在多个最小径向间距MRS(Minimum Radial Separation)圆心的问题。按照被测轮廓的表示,该方法可分为两类:一类是用被测工件表面上取的样本点来近似地表示该轮廓;另一类是用这些样本点产生一个简单多边形来表示该轮廓。这两种方法确定的内接圆是不同的。文章对比分析了它们的适用性、精度和计算效率以及存在的问题。 相似文献
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提出采用量子遗传算法,以提高圆度测量精度。首先用最小二乘法拟合获得建模数据中圆度图像的圆心坐标和半径;再通过圆度计算剔除不符合要求的圆度;然后用量子遗传算法进行多进制编码,量子旋转门非固定步长调整更新;最后给出圆度误差测量流程。实验仿真显示该算法获得了精确的测量数值,与三坐标测量机测量结果误差相差小于0.005 8 mm,半径相对误差小于0.19%,测量最大误差均在0.01%以内,同时最大误差波动比较平稳,测量不确定度比其它方法值较低。 相似文献
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为了定量描述石粉颗粒的圆度,本文中提出一种采用BET法间接测定石粉颗粒圆度的新方法,介绍了其原理和测定方法。实例表明,石粉颗粒表面的分维数间接地刻画了其圆度,此法可以定量描述磷渣、水泥、硅粉等粉末颗粒的圆度。 相似文献