五轴联动加工中局部轨迹优化方法

Local Tool Path Optimization Method for Five-Axis Linkage in Machining

摘要: 在五轴联动过程中，刀路轨迹的好坏直接影响到零件的加工效果。由于目前CNC系统普遍采用线性插补技术，刀具轨迹采用线性线段描述，这导致在节点处切向不连续，影响刀具的运动姿态，从而降低了曲面的制造精度。本文的目的是优化局部刀具轨迹，使刀具在线段连接部位平滑过渡，具体实施方法是：通过三次方B样条曲线在相邻线段构造新的控制点，这样能够满足刀具在拐角处2阶连续，保证刀具平滑过渡。实验证明，该方法可以提高五轴机床在复杂曲面上的制造精度。

Abstract: In the process of the five-axis linkage, the path of the tool directly affects the machining effect of the parts. Since the linear interpolation technique is widely used in the CNC system, the tool path can be described by a linear segment, which causes the cutting direction of the nodes to be incontinuous at the nodes. The purpose of this paper is to optimize the local tool path so that the cutting tool in the line segment connecting part can transit smoothly, and the specific implementation of the method is to construct a new control point by the Cubic B-spline curve in the adjacent segment. This can meet the 2-order continuousness in the corner of the cutting tool to ensure the smooth transition of the tool. Experiments show that this method can improve the accuracy of five-axis machine tools on complex surface.