Abstract: To maximize the property of five-axis CNC machine tool and improve it efficiency without impairment of precision, an adaptive velocity planning algorithm under complex constraints is proposed. Taken confined chord error, tangential movement of cutter and driving performance of axis into consideration, a time-optimal velocity planning model is established; expressing velocity profile with second-order B-spline in the displacement-velocity coordinate system to reduce the dimension of the optimization variables and improve efficiency of the model solving; A penalty function with continuous first-derivative is conducted to remove constraints of the model; a robust solution strategy for solving the model is designed based on BFGS algorithm. As shown in simulation, the proposed algorithm is advanced in dealing with complex tool paths efficiently. velocity profiles derive from the algorithm satisfy various of constraints well and increase processing efficiency markedly. The practice machining of S-shaped specimen further validates effectiveness of the algorithm.

Key words: five-axis CNC, adaptive feedrate planning, jerk constraint, B-spline velocity profile