Automated Robotic Wire Arc Additive Manufacturing with Integrated Sensing

Wire arc additive manufacturing (WAAM) is an additive manufacturing technology that uses an industrial robot to deposit melted metal wire on a substrate to form desired geometries.  This paper describes an end-to-end implementation that incorporates part slicing, robot motion planning, part metrology, in-process sensing, and process tuning.  The contribution includes the overall system architecture that integrates multiple robots and sensors, coordination of multiple robots for WAAM and sensing, and final product assessment.  We use Robot Raconteur, an open-source control and communication framework, as the middleware to integrate robots and sensors from different vendors.  The current implementation uses Motoman robots and Fronius weld controller, but the approach may be applied to products from other vendors.  The WAAM testbed implementation demonstrates an end-to-end 3D part welding process, with the average shape error below one millimeter and the worst case error below 3 millimeters.