Robot Trajectory Generation for Multi-Axis Wire Arc Additive Manufacturing

Metal additive manufacturing technology that uses arc welding technology to deposit material is called wire arc additive manufacturing. Robotic manipulators that have a large workspace to size ratio are used to enable wire arc additive manufacturing. Wire arc additive manufacturing is gaining popularity due to the fast build time achieved by the high material deposition rates. It can build large-scale parts at a faster speed compared to other metal additive manufacturing processes. Utilizing a tilting build platform along with a robotic manipulator referred to as a multi-axis setup can enhance the capability of wire arc additive manufacturing. It will allow the setup to build complex supportless geometries that are not possible otherwise. However, maintaining a constant layer height while performing multi-axis wire arc additive manufacturing is challenging due to the forces involved in the process. This paper presents a new sensor-based two-step process along with the tool trajectory generation for maintaining constant layer height while performing multi-axis wire arc additive manufacturing. As the first step, we regulate the tool trajectory velocity to minimize the variation in the layer height. In the second step, we develop a sensor-based intervention scheme to fix the variation in the layer height by introducing additional height compensation layers. Finally, we test our approach by building a few parts, including a tool for the composite layup process.