中文摘要：

提出针对金属曲面表面非金属涂层的逆向工程加工系统.由改造的840D数控系统作为采集轨迹控制系统和加工控制系统,对工件自由曲面自动采集形貌特征并储存.工控机通过以太网与数控系统交换数据并生成小线段数控加工程序.为提高加工效率,减小拐点加速度突变产生冲击,提出以NURBS样条程序代替小线段加工程序的程序后置处理方法.该方法与传统的NURBS样条拟合算法不同,直接以小线段的拐点作为样条的控制顶点构造曲线,避免繁琐的拟合运算,提高程序处理效率,在小线段拐角较大的衔接点通过修改样条形状的方法减小误差.在工件喷涂完涂层后,系统通过激光传感器实现自动对刀.最后通过加工试验证明该加工系统高效、稳定和实用.

英文摘要：

A new profile modeling machining system is presented,which processes the foam coating on the surface of aircraft to be uniform thickness.840D CNC,a laser sensor which is installed on the spindle and industrial personal computer are employed to form the system.The feature of the flee-form surface is sampled and modeled by CAM software to generate continuous micro-line NC program.NURBS is introduced to NC program post-processing to make the machining high-efficiency and smooth.The main idea of program post-processing algorithm is to construct NURBS curves base on letting inflection points be control points and modifying it by changing the control points,instead of fitting a NURBS curve based on letting measured points be data points,which is time-consuming.The laser is used for precise positioning work piece.Finally,experimental results verify the effectiveness of the processing methods.