【摘要】 结合运用自由度和变动思想,给出轴线基于自由度变动的数学表示。研究变动建模的约束条件,以此为基础详细研究当轴线特征两端给定的定位公差要求不相等时的各种变动建模方法,准确地表示轴线公差约束的语义。针对在三维CAD系统中实现变动建模效率低的情况,研究基于区域分割算法和预计算处理的高效变动轴线建模实现方法,最后给出应用实例分析。更多还原

【Abstract】 Tolerance modeling is imperative for the integration of CAD and CAM. Variational modeling for the centerline with unequal locational tolerance is researched. Based on the DOF and variational model, the variational DOF based representation is given for the centerline. The limitation conditions for model- ing the unequal tolerance specification are analyzed. And the variational modeling method is proposed for the centerline with unequal locational tolerance. With this model, the semantics of unequal locational tolerance is exactly interpreted. Furthermore, based on region division strategy and pre-calculation method, an efficient realization method for generating variational cen- terline without any Boolean intersection operation is researched in 3D CAD systems. At last, some test examples are given.更多还原