A look-ahead interpolator with curve fitting algorithm for five-axis tool path

摘要

In this paper, a look-ahead interpolator with curve fitting function is presented to generate smooth five-axis velocity profile and tool center point (TCP) trajectory. The generalized forward and inverse kinematics model of five-axis machine tools is derived based on screw theory. The developed method detects the break-point where any motion axis reverses or stops, and determines the feedrate respecting jerk limit at each corner and break-point. To achieve high-speed machining, sequential short segments in five-axis tool path are fitted to long linear segments with given chord tolerance. TCP feedrate profile is evaluated by five-axis feedrate regulation formulation (FFRF) and adjusted based on the constraints on velocity, jerk and segment length of five motion axes and TCP. S-shape feedrate profile is obtained using backward scanning algorithm. Finally, the effectiveness of the proposed look-ahead algorithm is validated in the cutting experiments on a five-axis engraving machine.