Research Initiation: Computer Generated Computer NumericallyControlled Machining Feedrates with In-Process Tuning

为了提高数控加工的效率，本文研究了一种自动生成进给速度的计算机系统。通过在加工过程中调整进给速度来处理材料特性和刀具几何形状的变化，也提高了可靠性。目标是通过：(1)集成几何和机械端铣削模型的体积计算和自动选择进给速度铣削雕刻表面；(2)通过比较实际切削力（功率）与预测力（功率），在加工过程中调整程序进给速度。从实验验证的立铣削过程的机械和几何模型中，开发了一个程序来自动选择复杂的雕刻立铣削的进给速度。该程序将使用工业合作伙伴提供给研究团队的数控（NC）程序进行实验测试。该程序用于加工复杂雕刻表面的冲压模具。在切削时间、公差和表面光洁度方面的结果将与手动设置进给和速度的工业结果进行比较。编程进给速度的在线调节能力将被添加到新罕布什尔大学数控机床上，以提供一种方法来适应不同的工件材料和刀具磨损。这一项目将带来四项最新进展：(1)改进立铣削过程的机理模型；(2)将力学模型和几何模型整合为一个系统；(3)基于几何公差信息计算所需立铣刀切进给速度的方法；(4)一种经实验验证的在线调速方法。

This research effort is focused on a computer system for automatic generation of feedrates for improving the efficiency of Computer Numerically Controlled (CNC) machining. Reliability is also improved by in-process adjustment of the feedrates to handle material property and cutter geometry changes. The goals are to be accomplished through: (1) integration of geometric and mechanistic end milling models for volume calculations and automatic selection of feedrate for milling sculptured surfaces; (2) in-process adjustment of the programmed feedrate by comparing the actual cutting force (power) to the predicted force (power). A program to automatically select the feedrates for complex sculptured end milling cuts is to be developed from experimentally verified mechanistic and geometric models of the end milling process. The program will be experimentally tested using Numerically Controlled (NC) programs supplied to the research team by an industrial partner. The programs are used for machining stamping dies for complex sculptured surfaces. The results in terms of cutting time, tolerances, and surface finish will be compared to industry results, where feeds and speeds are set manually. On-line adjustment capability of the programed feedrates will be added to the University of New Hampshire CNC machine to provide a method to adapt the feedrates to different workpiece materials and cutter wear. This project should lead to four advances in the state-of-the- art: (1) an improved mechanistic model of the end milling process; (2) integration of mechanistic and geometric models into one system; (3) method to calculate the necessary end milling cutting feedrates based on geometric tolerance information; (4) an experimentally proven on-line feedrate adjustment method.