Model-driven path planning for robotic plasma cutting of branch pipe with single Y-groove based on pipe-rotating scheme

The automatic cutting of intersecting pipes is a challenging task in manufacturing. For improved automation and accuracy, this paper proposes a model-driven path planning approach for the robotic plasma cutting of a branch pipe with a single Y-groove. Firstly, it summarizes the intersection forms and introduces a dual-pipe intersection model. Based on this model, the moving three-plane structure (a description unit of the geometric characteristics of the intersecting curve) is constructed, and a geometric model of the branch pipe with a single Y-groove is defined. Secondly, a novel mathematical model for plasma radius and taper compensation is established. Then, the compensation model and groove model are integrated by establishing movable frames. Thirdly, to prevent collisions between the plasma torch and workpiece, the torch height is planned and a branch pipe-rotating scheme is proposed. Through the established models and moving frames, the planned path description of cutting robot is provided in this novel scheme. The accuracy of the proposed method is verified by simulations and robotic cutting experiments.