A predictive feedrate schedule method for sculpture surface machining and corresponding B-spline-based irredundant PVT commands generating method

摘要

In order to improve the precision and efficiency of the sculpture surface machining, this paper provides a predictive sculpture surface feedrate schedule method and corresponding B-spline-based irredundant position-velocity-time (PVT) commands generating method. Due to the calculation complexity of feedrate scheduling and parametric interpolation for the sculpture surface machining, those complex computation processes are calculated offline to improve the calculation robustness and accuracy. After feedrate profile is scheduled, the sculpture surface machining data not only contains the geometric information but the dynamic processing information. In order to apply the sculpture surface machining data in machining process, a B-spline-based irredundant PVT interpolation (the PVT interpolation is commonly used in motion control card and is the cubic Hermite interpolation in numerical analysis.) commands generating method is provided. In this method. the characters of the machining data and the PVT interpolation mathematical model are analyzed. And then, a given accuracy B-spline fitting method is proposed to convert the machining data to the accurate and irredundant PVT commands. At last, the sculpture surface part is machined through PVT interpolation method with the PVT-based sculpture surface machining data which contains the feedrate profile and toolpath geometry information. In order to prove the feasibility and superiority of the proposed sculpture surface machining method, sculpture surface machining simulations and experiments are carried out.