【摘要】 为了在产品公差设计时考虑制造几何变动,将CAD模型中零件模型及其特征用点集形式表示.采用机器人运动学中的齐次坐标变换来描述工艺系统各组成部分的空间位姿关系,建立了工艺系统各组件的几何误差累积模型.将制造过程看作是刀具轨迹形成的点集更新被加工零件点集的过程,加工后零件点集组成了新的齐次坐标矩阵,该矩阵包含了零件的制造几何变动信息.采用Monte-Carlo仿真研究了特征面制造几何变动,实现了基于CAD环境的制造过程模拟和制造误差传递分析,从而可在公差设计阶段就考虑制造几何变动,实现了公差并行设计.更多还原

【Abstract】 The part model and its features in a CAD system were represented by a group of points to take into account the manufacturing geometric variation in the stage of product tolerance design.The changes of space pose of each component in the process system were described by homogeneous transformation based on the kinematics principle of robot,and then a stack-up model of geometric error of the process system was established.A machining process could be regarded as the up dating of the point-group of tool by that of part.Then,a new homogeneous coordinate matrix of the machined part was established,which contained the manufacturing geometric variation information of part.The manufacturing geometric variation of the feature surface of part was analyzed using Monte-Carlo simulation.The results show that the model can simulate the manufacturing process and analyze the propagation of manufacturing error based on CAD environment.Therefore,the manufacturing geometric variation can be considered in the tolerance design stage and the concurrent tolerance design is actualized.更多还原