组合曲面三坐标加工刀具路径后处理优化技术

摘要

Now the tool path of compound surface NC machining is generally exported in the form of line segments. So as to obtain fairing tool path and short program, an optimization method based on constrained optimization and feature identification is presented in this paper. First of all, a constrained optimization model, which is subject to the tangent condition between adjacent curve segments, is constructed. And it is solved in use of disciplinal function method. Then the type of curve segment is identified by the present model. According to identifying results, the cutter location points are fitted with lines or arcs. Thus the first-order continuous tool path rows are acquired, and their approximation error is less than the specified machining error. The results indicate that the length of program code can be shortened greatly. Furthermore, the movement state of machine tool feed system is smoother when moving along first-order continuous path.%针对目前组合曲面加工刀具路径后置处理时只输出直线段的缺点，提出一种基于约束优化与曲线特征识别的刀具路径优化技术。建立了相邻曲线段之间满足一阶连续条件的约束优化模型，并采用惩罚函数法将约束优化模型转化为非约束优化问题进行求解。采用建立的优化模型对刀位点数据进行特征识别，根据识别结果将刀位点用直线和圆弧进行拟合，使逼近误差小于给定的加工误差，并保证输出的刀具路径行满足一阶连续条件。结果表明：应用该方法对刀具路径进行优化处理，缩短了程序代码的长度；整体一阶连续的刀具路径，使机床进给系统的遗动过程更加平稳。