The well-designed feedrate optimization algorithm can obtain higher machining efficiency with various machining related constraints, thus, it is widely considered in the high-speed and high-precision machining. However, the low computational efficiency still limits the application of the optimization method. For the non-linear optimization problem of spline toolpath with feedrate-, actuator velocity-, acceleration- and jerk-limited, a linear approximation is adopted by a pseudo-jerk method and the efficient linear programming method can be applied to solve the optimization problem. To improve computational efficiency further, curvature-base window technique is presented and the whole spline toolpath is split at the curvature extreme points, which are also named critical points in traditional planning method. Thereafter, a novel feedback interpolation is presented based on Steffensen iterative accelerator method to eliminate the feedrate fluctuation caused by nonanalytic relationship of spline parameter and arc-length. Finally, simulations and experiments validations show that the proposed method is able to reduce computational burden and traversal time notably with multi-constraints.
Novel Feedrate Optimization Method for NURBS Tool Paths Under Various Constraints
