【作者】 陈益林；

【导师】 杨茂奎；

【作者基本信息】 西北工业大学 ， 机械设计及理论， 2004， 硕士

【摘要】 随着工业的不断发展，零件的几何形状越来越复杂，加工仿真已成为实际数控加工前NC程序验证和CL数据证实必不可少的一个环节。它也是CAD／CAM、CIMS和虚拟制造的重要内容之一，其中五轴NC加工仿真越来越受到研究者的重视，本文在参阅了大量相关文献的基础上，主要对五轴NC铣削加工几何仿真中的仿真速度、三维图形显示质量、仿真误差三项关键技术进行了研究。 在仿真速度方面：根据包络理论，以通用刀具几何模型为基础推导了刀具扫描体的显式求解方法，相对刀具扫描体的隐式求解方法，较大地提高了扫描体的计算速度；采用快速定位方法和快速求交算法，提高生成刀具扫描体dexel模型的速度；采用dexel模型的一维布尔运算方法，大大提高了“材料”移除过程的计算速度。 在图形显示方面：改进传统的dexel模型显示方法，在OpenGL环境中借助三角面片显示仿真图形，成功地实现了仿真图形的任意视点变换；采用改进WM_PAINT机制的动画方法和实时获取键盘消息的方法，提高了图形的显示质量和人机交互性能。 在仿真误差方面：通过对工件逼近误差、采样点的拾取误差和扫描体逼近误差的分析，给出了误差的计算公式和误差控制方法，提出了dexel优化建模方法，建立了仿真环境中的加工误差模型、刀杆与工件的干涉与碰撞检测模型。 另外，为了使本仿真模块能应用于CL数据驱动的加工仿真，在机床坐标系中建立了CL数据变换为本仿真模块驱动数据的数学模型。 经过加工仿真实验表明：五轴NC加工几何仿真在个人PC机上达到了仿真的实时性要求，有较高的图形显示质量和较好的人机交互性能。更多还原

【Abstract】 With the development of modern industry, the geometrical shape of a part is becoming more and more complex. Machining simulation has become an indispensable and important processing to verify NC programs and CL data before actually machining. It is also an important field in CAD/CAM, CIMS and virtual manufacturing. Specially, many investigators have attached importance to 5-axis NC machining simulation. In this thesis, three key technologies have been solved partly such as simulation efficiency, high quality three-dimensiona graphics display and simulation errors.For efficiency of simulation, the explicit solution has been obtained based on the theory of envelope with the geometrical model of general cutter. Calculational efficiency of a sweep volume of cutter has been geatly enhanced by our method comparing with the conventional implicit method. The approachs of finding intersecting points rapidly between triangles and lines which paralleling Z-axis and rapid location are proposed to improve forming dexel model of sweep volume of the cutter. One-dimensional bool subtraction of dexel models can be used to improve the efficiency of the processing for removing material.As far displaying graphics, the point-view can be changed during machining simulation by displaying the perspective projections of triangles with OpenGL. Those techniques such as prefect WM_PAINT mechanism for animation and real-time capturing keyboard message are adopted to enhance the quality of graphics and the performance of man-machine interaction.As far as simulation errors are concerned, analyzing approximation and sampling error of work-piece and cutter introduce models and controlling methods of errors. An optimized dexel model is presented as well. Machining error and collision detection are modeled between cutter holder and work-piece in simulation.Moreover, CL data driving the simulation model conversion model from CL data to inputting data for machining simulation in the machine coordinate frame is represented to drive models of simulation by CL data.Experiments are conducted to demonstrate the developed methods. The results show that these techniques are very efficient for real-time machining simulation, high quality three-dimensional graphics and performance for man-machine interaction.更多还原