Dual-camera-based method for identification and location of scattered self-plugging rivets for robot grasping

Abstract With the development of robotic vision technology, applications of visual guided robotic grasping and assembly become more and more widespread in aerospace industry. Self-plugging rivet with complex structures plays an important role in connection of aircraft and spacecraft. This paper focus on identification and location of scattered self-plugging rivets for robot automatic grasping. In this paper, the structure and rivet measurement elements are analyzed and the calculation method of grasping point and angle is introduced, firstly. Secondly, the rivet image processing method based on multiple corrosion and expansion operators is proposed, and rivet contour is obtained initially. Thirdly, in order to determine the grasping angle uniquely, a method of multiple times subtraction with mask image is proposed. In addition, the rivets’ skeleton lines are rebuilt with binocular and the effects of threshold value are studied. The reconstruction and gripping accuracy is verified through a standard board with marker points. Vision-guided robot rivet grasping experiment succeed finally. Experiment results show our detection algorithm is effective and the grasping system can completely satisfy the industrial requirements.