针对集成变量化设计中三维几何约束和装配几何约束的混合建模与求解问题,提出改进的有向图方法.该方法采用几何约束的基本约束表达和几何实体的抽象对偶实体表达,引入定向弧表达实体之间的内在依赖关系建立混合几何约束有向图模型 结合约束有向图的优化处理,实现了几何约束系统的细粒度分解和高效并行求解.最后用实例验证了文中方法的正确性和有效性.
A modified directed graph method is proposed to solve hybrid geometric constraint systems including 3D geometric constraints and assembly constraints derived from integrated variational design.Firstly,several basic constraints are defined to describe diverse geometric constraints,and two abstract dual objects are used to encapsulate various geometric entities.Then,the hybrid geometric constraint digraph model is established by introducing the irreversible directed arc to represent the intrinsic dependency between two interrelated objects.Subsequently,the optimal decomposition of geometric constraint system is achieved by optimal processing of the constraint digraph,from which the efficient parallel solving sequence can be obtained.Finally,a series of examples are presented to demonstrate the correctness and effectiveness of the proposed approach.