Overlap classification-based and kinematically coordinated corner rounding using double asymmetrical transitions for five-axis short-segmented tool path

Abstract

For traditional corner rounding methods that adopt a pair of symmetrical and asymmetrical transition curves to round the corners in tool tip position and tool orientation, there are still two critical issues remain unsolved. One is the overlaps between adjacent transition curves have to be eliminated specifically to avoid the excessive approximation of the transition curves to the corners, the other is the asynchronous motions between tool tip position and tool orientation on the transition curves need to be addressed in addition to achieving smoothness at the junctions between transition curves and linear segments. For solving these two issues, this paper proposes the overlap classification-based and kinematically coordinated double asymmetrical transitions to round the corners. In this method, the overlaps between adjacent transition curves in tool tip position and tool orientation are first classified. Then, parameter synchronization is derived analytically and a targeted overlap elimination strategy is also proposed, so that the transition lengths without forcing the transition curves over-approach the corners are determined. Furthermore, to alleviate the asynchronous motions, the kinematics coordination between tool tip position and tool orientation is introduced, which is utilized to further evaluate the transition lengths to improve the kinematics performance of rotary axes. Finally, the computer simulations and machining experiment both demonstrate that our method can improve the feedrate and achieve the low acceleration and jerk of rotary axes indeed.