【摘要】 球压测试被广泛应用于电工学装置中非金属物质的耐热性检测,检测的关键在于明确测量的是压力球和样品表面相切圆的直径而非整个压痕的直径;目前的测试大多数由测量人员根据经验去判断相切圆,因此试验准确率较低;将数字图像测量技术应用于压痕检测中从而提出一种基于数字图像处理技术的球压测试压痕自动测量技术,其基本思想是对采集到的压痕图像进行阈值变换增强边缘对比度,然后通过轮廓跟踪和改进的随机Hough变换判断出相切圆并自动计算出有效直径;实验结果经三维扫描检验误差不超过1.5%。更多还原

【Abstract】 Ball-pressure test has been widely implemented as a method for testing non-metallic materials for resistance to heat for electrotechnical equipment.The test result was determined by the valid diameter of indentation at the tangent points,not the complete indentation.At present it was determined by experience and is subjected to variety problem due to person difference.In this paper,based on the digital image processing technique,a method for automatically measuring of the valid diameter is put forward.In this method.The indentation image is acquired by CCD and stored in the computer,after optimal thresholding the valid diameter is calculated by contour tracking and improved randomized Hough method.1t is proved by the three—dimension scanning that the automatic measurement method put forward in the paper is feasible.更多还原