Interlayer parameter adjustment for robotic wire-arc directed energy deposition of inclined thick-walled components with varying layer width

During the robotic wire-arc directed energy deposition (WA-DED) of inclined structures, a varying-layer-width feature demands adaptive adjustment of the deposition parameters for enhancing the manufacturing accuracy and maintaining the process stability. This paper proposes a novel mechanism for controlling inclined structures with varying layer widths. The mechanism continuously adjusts deposition parameters of subsequent layers to reduce height deviation during the deposition process. Conceptual fundamentals of the control mechanism are presented after the WA-DED process requirements are analyzed in detail. Stability criteria are developed by representing the control process as a second-order ordinary differential equation. A controller with a pyramid structure is implemented in the simulation for optimizing the controller parameters. On the validation side, a funnel-shaped component is treated as the target of experimentation. As suggested by the experimental results, the optimized control mechanism exhibits a fast convergence speed of error and performs well in the presence of minor deviations, which can eliminate the accumulation of height error and enhance the surface flatness of the fabricated part.