Clear Image Acquisition by 3D High-speed Vibration Tracking Using High-speed Vision System

In this paper, using a high-speed vision system, we propose high-speed autofocus methods to acquire clear images of vibrating objects in the focal direction, in order to realize in-line precision visual inspection. These methods include a single-process method with a single camera, and a multi-process method with a laser displacement meter, to estimate focal lengths. We evaluated the high-speed autofocus performance for vibrating objects in the focal direction using a vibration tester. In addition, since the vibration is not only in the focal direction but generally in three dimensions, we established a method to track this three-dimensional high-speed vibrating object and acquire clear images at high speed. Compared to the ideal autofocus performance defined in this study, high-quality results of 110% for simple harmonic motion and 146% for rotational motion were obtained, proving that the system is highly practical.