Posture constraint–based tool orientation planning method for dual-tool mirror milling

Multi-tool machining is widely utilized in manufacturing processes such as multi-tool drilling, multi-tool turning, and dual-tool milling. However, research on the coordinated control of multiple tool postures remains limited, with systematic studies on collaborative planning methods for tool orientations being particularly scarce. This study proposes a general tool orientation planning method for dual-tool mirror milling, applied and validated on a self-developed dual-tool machine. First, a tool posture optimizing function is designed to determine the optimal tool orientations, considering the smoothness of tool orientation distribution, the mirror-symmetrical relationship between tools, and the deviation between theoretical and initial tool posture angles. Second, a tool orientation representation matrix is constructed based on the dual-tool machine, with matrix parameters used to represent the machine’s structural constraints and workpiece surface geometric features. Finally, the planning method for mirror milling is conducted using the blade surface of a steam turbine. The influence of the initial posture angles and matrix parameters on the distribution of tool orientations is analyzed based on the simulation model, and on-site cutting validation is performed. Simulation and experimental results confirm the feasibility and reliability of the method. This method and its derived conclusions can serve as a reference for tool orientation planning in multi-tool machines with diverse structural configurations.