侧铣加工自由曲面刀具路径轨迹规划关键技术研究

Flank milling is suitable for freeform surface machining, especially for ruled surface machining for its geometric characteristics. Although the machining efficiency can be improved greatly by flank milling method relative to the ball milling method, application of flank milling method is restricted to the difficulties, such as the adjustment of collision avoidance. In this research, Kinematics theory and freeform surface modeling theory are used. Methods of machining error model construction and global optimization of tool axis are analyzed. Differential geometry is used to construct the method to weight the machine errors model. Adjustment and global smooth of tool axis of tool-path planning are investigated. Model of double NURBS curve interpolation to be output directly for flank milling is studied and non-linear errors model of flank milling is studied also. Key technology and difficulty of the research are the construction of non-linear error model based on the real structure of machining center and the construction of the machining error model to weight the design freeform surface and the swept envelop surface of machine tool. Application of the research can provide the basis theory of ruled surface machining using flank milling method.

自由曲面中的直纹面以其几何特性适用于侧铣加工，相对于球头刀点接触加工方式可以极大提高加工效率，但是侧铣加工的应用受限于干涉调整困难等关键技术。本项目采用运动学理论、自由曲面建模理论，分析加工误差模型的建立和刀具姿态的整体优化方法，借助微分几何建立评价加工误差函数模型的方法，探讨刀具路径轨迹的刀轴矢量整体平滑方法和调整方案，研究侧铣加工刀具路径轨迹双NURBS样条曲线插补直接输出模式，分析侧铣加工非线性误差模型。本项目的难点和关键问题在于，衡量设计曲面与刀具包络面的加工误差模型的建立和基于实际机床运动结构的非线性误差模型的建立。本项目的实施将为五轴联动侧铣加工直纹面类航空关键零件提供理论基础。

自由曲面以其优良的空气动力学和流体动力学等特性，广泛应用于航空航天、造船、汽车、精密模具等领域。相比较端铣加工方式，侧铣加工自由曲面具有高效率和高精度的优点，本项目以提高自由曲面加工精度和加工效率为目的，针对侧铣加工自由曲面刀具路径轨迹规划关键技术进行了深入的研究。首先建立曲面模型和刀具包络面模型，根据曲面模型与刀具运动包络面之间的距离关系，建立侧铣加工自由曲面的误差理论模型；基于加工误差的同步干涉检测方法提出了一种干涉区域边界追踪算法，研究了多刀具尺寸组合算法，并分区域规划刀具路径轨迹，从而减少刀具路径轨迹总长度，提高加工效率；研究基于关键点提取建立样条曲线的节点矢量，给出侧铣加工刀具路径轨迹双NURBS样条曲线插补G代码模式；基于实际五轴联动加工中心机床机构，研究了五轴侧铣加工时的非线性误差模型的建立，最后进行计算机仿真及加工实验验证。.本项目研究过程中，已经共计发表学术论文4篇（不含录用论文），其中EI检索论文2篇，核心期刊论文2篇，会议论文1篇，另有多篇论文待发表或修改、审稿中；申请专利11项，其中授权发明专利5项，进入实审发明专利4项，授权实用新型专利2项。