Development of Integrated Automatic System of Laser Cladding for Repairing of Polycrystalline Diamond Compact Bits

Abstract

In order to improve the automatic level for laser-cladding repair of high value industrial equipment, such as polycrystalline diamond compact bit (PDC bit) applied in oil industry, a universal scheme of integrated automatic system for repairing is proposed in this paper, and the basic functional modules together with the executing order according to which each module runs are defined. There are two main technical points, i.e.,inspection and repairing, that need to be realized for such integrated automatic system. Therefore, according to the proposed scheme and the existing instruments, a dual-robot system, which includes two KUKA industrial robots, is adopted as the technological implementation, where one robot is used to carry a 3D scanner to reconstruct the PDC bit to realize inspection while the other is used to hold the laser to melt the special powder flowing to the damaged region of the bit to complete cladding. To realize automatic running of the whole integrated system, a hand-eye calibration method, namely three-point calibration, is then proposed, by which coordinates of point cloud of the damaged PDC bit detected by 3D scanner can be transformed to those of the coordinate system of the robot with the laser, so that the cladding path planned via cutting slice of the damaged region of the PDC bit in the upper computer software, the key of the integrated system developed by QT programming tool, can be tracked by laser head and then the damaged part of the PDC bit can be repaired. Finally, a laser-cladding experiment for repairing PDC bit is carried out and the feasibility of the proposed scheme of the integrated automatic system and the effectiveness of the dual-robot system implemented via KUKA robots are verified, According to existing literature, no papers about such integrated system for automatic laser cladding repair have been published.