An Analytical Decoupled Corner Smoothing Method for Five-Axis Linear Tool Paths

Abstract

Nowadays, the tool path in five-axis machining is usually described with linear segments. Tangential and curvature discontinuities of the linear tool path lead to poor machining efficiency and quality. Due to the complexities in constraining approximation errors and synchronization of tool tip position and tool orientation, it still remains a challenge to smooth five-axis linear tool path in real-time. To solve this problem, this paper developed an analytical decoupled corner smoothing method by inserting an asymmetric cubic B-spline and a pair of symmetric quartic spherical Bézier curves for tool tip position and tool orientation, respectively. The maximal approximation errors for tool tip position and tool orientation are fully constrained in the blending procedures. Tool tip position and tool orientation are synchronized by adjusting the blending lengths and angles, which guarantees the C2 continuity of the tool path. The blending and synchronous scheme are analytical. Therefore, the proposed method can be employed in real-time. To verify the proposed method, simulations and experiments on a five-axis machine tool are conducted, the results demonstrate the feasibility and efficiency of the proposed method.