A Robotic Defect Inspection System for Free-form Specular Surfaces

In this paper, we present a robotic system to automatically perform defect inspection tasks over free-form specular surfaces, which the image acquisition sub-system is equipped with a 6-DOF robot manipulator to achieve flexible scanning. Given the mesh model of the workpiece, we implement K-means based region segmentation algorithm on the point cloud after preprocessing. Then, we take the smooth regions as input to plan the scanning path. A projection registration method that robustly localizes the object in the robot’s frame is proposed for real-time workpiece localization. According to the optical features of the high-resolution line scan, we design an image processing pipeline to detect defects from the captured images. We report a detailed experimental study to validate the proposed methodology.