Laser line generation for optimized interaction with hidden defects in active thermography

In this paper, an active thermal imaging technique using a laser as an excitation source is used to detect aluminum specimens containing artificial defects. The presence of defects in the local excitation of the laser can produce better edge effects, using different laser excitation methods to improve edge effects. In the experiment, the laser scanning method is designed according to the characteristics of artificial defects, and the experimental data is analyzed. PPT and Sobel filtering are used to further data processing to obtain clearer defect edges and detect the detailed features of the defects. The study found that the detection effect is the best when the laser power and pulse width are large.