Displacement measurement in impact tests based on machine vision

Contact measurement is difficult to arrange sensors under various impact tests. And the method of measuring displacement by machine vision has significant advantages. This paper proposes a displacement measurement method based on machine vision. Firstly, YOLO (You Only Look Once) v5 is used to automatically extract the recognition targets in various test scenarios. Secondly, the extracted recognition target graphics are processed by image enhancement and threshold segmentation technology. Then, the geometric shape of the processed graphics is identified by edge detection technology, and the scale factor is calculated. Finally, the displacement of the target structure is calculated through coordinate transformation in multiple coordinate systems. The results show that for a single recognition target, the relative error between machine vision and sensor measurement is within 5%, and for multiple recognition targets, the relative error between machine vision and industrial software measurement is within 15%.