考虑几何、控制及工艺耦合集成的五轴数控加工轮廓误差控制理论研究

项目名称： 考虑几何、控制及工艺耦合集成的五轴数控加工轮廓误差控制理论研究

项目编号： No.51505167

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 机械、仪表工业

项目作者： 杨吉祥

作者单位： 华中科技大学

项目金额： 20万元

中文摘要： 轮廓误差是数控加工的重要精度指标，直接影响工件的尺寸及形貌。传统研究多从几何和控制两方面提高轮廓精度，而轻视了工艺过程的影响。本项目以复杂曲面类零件高速、高精度五轴加工需求为背景，围绕如何集成几何、控制以及工艺过程综合影响的问题，研究五轴高速数控加工轮廓误差的控制理论与关键技术。具体研究内容有：综合考虑几何误差、惯性力和切削力约束的五轴刀具路径速度规划算法；轮廓误差线性近似计算模型以及预测控制方法；材料去除过程引起的电机轴等效惯量变化预估模型以及轮廓误差控制模型中相关参数的更新策略；算法和模型的实验验证。通过以上系统研究，实现对高速切削时各电机轴整体承载难以得到有效约束、轮廓误差反馈控制滞后、预补偿控制鲁棒性差、以及轮廓误差预测控制效果随材料去除过程恶化等问题的改进，进而建立五轴高速数控加工在切削力剧变以及高材料去除率等新型工艺特征影响下的轮廓误差控制理论体系。

中文关键词： 五轴加工；轮廓误差；工艺过程；速度规划；预测控制

英文摘要： Because of its direct affects to the dimension and shape of manufactured parts, contouring error is an important accuracy index of CNC machining. Traditional researches improve contouring accuracy through geometry and control aspects, while the actual cutting process is ignored. In order to realize high speed and high accuracy five-axis machining for complex surfaces, this project studies five-axis contouring control theory and its common techniques by considering the integral affects of geometry, control and cutting process. The research content includes: the feedrate optimization algorithm that synchronously consider constraints of the geometric errors, inertial forces and cutting forces; the linear estimation model of contouring error and its predictive control; the predictive model of equivalent inertia variance of motor axes caused by the material removal process and the corresponding model parameters update techniques; experiment verification of the proposed algorithms and models. Through the proposed research, the entire equivalent load of each motor drive is constrained while performing high-speed machining; the control delay problem of feedback control and the low robustness problem of pre-compensation control are avoided; the accuracy deterioration of predictive control caused by model parameter variance is solved. Finally, the systematic five-axis contouring control theory is built with the influence of the new cutting process characteristics caused by fierce cutting force variance and high material removal rate of five-axis CNC machining for complex surfaces.

英文关键词： five-axis machining;contouring error;cutting process;feedrate optimization;predictive control