Acquiring Clear Images for Objects Undergoing 3-D High-Speed Vibration and Low-Speed Motion and Its Evaluation

Automation of precision appearance inspection is critical in the manufacturing industry. In particular, on the production line, it is necessary to perform precision appearance inspection at high magnification on objects that are moving and vibrating. However, in our previous studies, high-speed vibration tracking technology using a high-speed vision system object moving at a slow speed can only be captured for an instant, resulting in a deviation from the viewing angle. In this study, to realize in-line precision appearance inspection, we propose a method to acquire clear images from a phenomenon in which high-speed vibration and low-speed movement are combined in a complex manner and evaluate its specifications. Four methods are proposed. The first is a method that captures objects passing within the field of view at high speed without tracking their low-speed movement and acquires clear images. The second is a method that statistically separates the movement and vibration elements of the object and tracks the vibration and movement with high precision to acquire clear images. The third is a method that uses a stereo camera to recognize the nearest object, track the object, and acquire clear images. The fourth is a method that uses a stereo camera to recognize differential objects, track the object, and acquire clear images. As a result, for a vibration with an amplitude of 1 mm in the planar direction, the limit frequency was 64.5 Hz for simple harmonic motion and 12.8 Hz for rotational motion, and for a vibration with an amplitude of 2 mm in the focal direction, the limit frequency was 10.0 Hz. The maximum movement speed was 29 mm/s, indicating that this is an efficient system that can acquire clear images at a frequency of more than $50\times $ /s.