基本数字图像差分法在活塞热裂纹自动检测的研究

Extracting Thermal Crack in Piston Using Basic Digital Image Subtraction Algorithm

模拟、自动试验技术在活塞热冲击可靠性的研究上已得到充分应用,但热裂纹的观测仍然依靠人工进行,因而不能及时、准确地获取裂纹扩展情况。通过在现有的试验台架上安装图像监控系统,采用基于联合灰度级分布的动态图像差分法,有效避免了光照的影响,得到热冲击过程中裂纹的扩展信息,为热损伤的量化分析提供了方法。

At present, the thermal crack is checked manually and the thermal damage procedure get, though the automatic testing technique has been employed in the thermal shock test. In this study, a thermal shock bench was improved to incorporate image measure system to get thermal crack information where pictures of piston were taken by a CCD camera periodically during the test. An effective image subtraction algorithm was studied for extracting thermal crack from the pictures regardless of variable illumination intensity.