The transition algorithm based on parametric spline curve for high-speed machining of continuous short line segments

摘要

A numerical control (NC) program generated by a complex CAD/CAM system mainly composes a number of short line segments. For continuous short line segment machining, the traditional machining approach and the direct transitional approach cause the oscillations of the federate and affect machining efficiency. Moreover, the arc transitional approach enhances machining efficiency, but it brings about the greater machining error. To increase the smoothness of velocity profile and machining efficiency of continuous short line segment machining, this paper presents a parametrical cubic spline curve transitional approach with the S-shaped jerk-limited acceleration and deceleration with look-ahead. The trajectory error of the transitional curve is deduced according to the correlative factors, the preconditions of the transitional curve are put forward and analyzed, the mathematical model of the parametrical cubic spline curve is constructed, and the constraint conditions of the transforming velocity are built. In addition, the velocity control method is adopted for the smoother velocity profile. Thus, the machining productivity is dramatically increased and the velocity profile is more smoothness. The simulative and experimental results verify the feasibility and validity of the proposed approach.