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基于最小外接圆法的苹果直径检测技术 被引量:4
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作者 沈宝国 魏新华 尹建军 《农机化研究》 北大核心 2011年第12期131-134,共4页
水果大小是水果机器视觉自动分选的重要依据。以苹果为研究对象,提出了一种利用最小外接圆检测苹果直径的方法。苹果样本为12枚,共计144幅苹果图像,经过图像处理后,获取每个苹果的12个近似圆度,选取最小近似圆度对应的外接圆像素直径作... 水果大小是水果机器视觉自动分选的重要依据。以苹果为研究对象,提出了一种利用最小外接圆检测苹果直径的方法。苹果样本为12枚,共计144幅苹果图像,经过图像处理后,获取每个苹果的12个近似圆度,选取最小近似圆度对应的外接圆像素直径作为该苹果的像素直径。通过对8组苹果像素直径和近似圆度与实测直径进行二元拟合,得到拟合方程,其相关系数为0.988。利用此方法估测苹果直径的绝对误差在±1.8 mm以内,同时能够确定果梗-花萼轴线与摄像机的光轴接近重合的那幅图像。该方法为利用图像中的水果姿态进行检测直径提供了新的思路。 展开更多
关键词 苹果 机器视觉 直径检测 最小外接 近似圆度
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浅谈圆弧半径间接测量的数据处理方法 被引量:1
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作者 谢建华 《计量与测试技术》 2002年第4期7-8,共2页
本文作者提出的数据处理方法大幅度地减少了运算量 ,大大提高了效率。
关键词 误差 位移量 弓高 近似 弧半径 间接测量 数据处理
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Large deflection of clamped circular plate and accuracy of its approximate analytical solutions 被引量:3
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作者 Yin Zhang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2016年第2期67-77,共11页
A different set of governing equations on the large deflection of plates are derived by the principle of virtual work(PVW), which also leads to a different set of boundary conditions. Boundary conditions play an impor... A different set of governing equations on the large deflection of plates are derived by the principle of virtual work(PVW), which also leads to a different set of boundary conditions. Boundary conditions play an important role in determining the computation accuracy of the large deflection of plates. Our boundary conditions are shown to be more appropriate by analyzing their difference with the previous ones. The accuracy of approximate analytical solutions is important to the bulge/blister tests and the application of various sensors with the plate structure. Different approximate analytical solutions are presented and their accuracies are evaluated by comparing them with the numerical results. The error sources are also analyzed. A new approximate analytical solution is proposed and shown to have a better approximation. The approximate analytical solution offers a much simpler and more direct framework to study the plate-membrane transition behavior of deflection as compared with the previous approaches of complex numerical integration. 展开更多
关键词 approximate analytical solutions large deflection PLATE MEMBRANE bulge and blister tests
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