TCP interpolation with look-ahead function for five-axis machining

Abstract

In this paper, a novel tool center point (TCP) interpolation method is proposed to generate smooth feedrate and tool trajectory for five-axis machining. TCP interpolator consists of two processes: block and look-ahead process. The block process determines the maximum feedrate of each block based on five-axis velocity equations, the movements of TCP and rotary axes. It detects sharp corners among NC blocks, and inserts arc segments into blocks with sharp corners to avoid tangential discontinuities. Corner feedrate is determined based on contour tolerance and kinematic constraints where velocity, acceleration and jerk on TCP and five-axis are all taken into consideration. The velocity profile of the TCP on each block is planned in the look-ahead process by means of TCP movement, corner velocity, velocity commands and jerk limits. Finally, simulations and experiments are carried out to validate the efficiency of the proposed method in improvement of the contour accuracy for five-axis machining.