基于折反射原理的层去反求技术研究

A New Slicing Method Based on The Principle of Refraction and Reflection

为了克服传统层去反求测量中图像衬比度较低的缺陷 ,提出一种新的基于棱镜反射原理的层去反求图像摄取方法。该方法利用棱镜的全发射和折射作用提高图像衬比度 ,根据物体反射率的高低可分别采用垂直照明和倾斜照明 ,分别可获得高衬比度的亮目标暗背景和暗目标亮背景图像 ,为了校正由于折反射引入的几何变形 ,推出了相应的数学变换模型。该研究已成功投入实际产品校正的应用中 ,研究表明这种新的层去法比起传统的层去法不仅在于图像衬比度高 ,而且物体截面图像的轮廓更清晰可靠、无需填充反差材料 ,有望在零件及模型的反求测量中发挥较大的作用。

To overcome the disadvantage of low contrast in the images taken with the traditional slicing method of reverse engineering, a novel slicing method of reverse engineering based on the principle of refraction and reflection of a prism is proposed to improve the contrast of the cross sectional images. According to the reflectivity of the object, one of the illuminating methodsstraight illuminating or inclined illuminatingis adopted to get the sharp contrast images of bright object in dark background, or dark object in bright background. To adjust geometrical distortions caused by the refraction and reflection of the prism, a mathematical transformation model is set up to correct the image by means of software. This method has been applied to some cases of reverse measuring. The research confirms that this new slicing method has not only the advantage of high contrast, but also the clear and reliable contours of the cross sectional images, what's more, there is no need of contrasting filling materials. It is hopeful that this method will play a great role in the reverse measuring of mechanical parts and models.