Development for non-contact displacement test method and its application verification

Non-contact displacement test method was proposed based on the circle detection using Hough transform, which was verified by the shaking table test. The verification results showed that Hough transform had a good performance on the circle detection. The computation efficiency on the images depended on the selected detection steps of the angle and radius. The processing speed of images increased sharply when a larger detection radius step was selected, however, the processing speed increased slightly when a larger detection angle step was adopted. The independently-developed non-contact displacement test method was verified under different testing conditions, considering the input sine wave with different frequencies, the target circle with different radius, and different camera-target distances. The results showed that the proposed method had a good recognition performance. Non-contact displacement test method can capture the displacement of several gauge points at the same time and effectively solve the problem of limited test range, moreover, it can avoid the interference to the measured objects.