Light Reflection Model of Pixel-based Surface Patch for Shot Peening Coverage Estimation

Nowadays, we need to efficiently control key parameters of the shot-peening process such as shot size, energy and peening angle, to ensure a positive and optimum effect on fatigue life. A good way to help us in adjustment of these parameters is to observe the resulting coverage after peening. Manual measurement and control of peening coverage – which consist of a visual inspection step by an operator – are highly subject to inspector interpretation, experience and error. Actually, however, they are still the main method of peening coverage estimation. An automatic visual inspection system was developed in this study to obtain stable evaluation data. We worked on a sequence of images of a peened surface illuminated with different lighting configurations. With the help of a ray reflection model, we implemented our algorithm for coverage estimation by shape from shading approach.