VRML环境下基于语义的产品装配设计技术研究

装配语义是零件间装配约束的抽象与概括，研究基于语义的产品装配设计可有效地提高装配设计的直观性与装配效率。文中给出了基于语义的产品装配设计系统的总体框架结构，将装配语义分为常用语义与特殊语义，并建立了装配语义的层次表达；通过装配语义与几何约束的映射，形成几何约束的代数表达；借助零部件间的运动自由度的求解，实现了装配语义的驱动，有助于将装配设计从几何层发展到语义层进行操作。

Product Assembly Design Based on Semantics in VRML Environment

Assembly semantics is the abstract and generalization of assembly constraints among parts, thus using semantics can prominently enhance the straight forwardness and efficiency of assembly design. This paper puts forward an overall framework and essential functions of semantics guided assembly design system, classifies the assembly semantics into general ones and particular ones, resulting in a paradigm of hierarchical representation of assembly semantics. By direct mapping from assembly semantics to geometrical constraints, the algebraic expression of geometrical constraints is established and the degrees of freedom of parts motion are solved. In such a way, the assembly semantics can be used to drive automatically the execution of assembly process, that helps to realize the assembly design with semantic instructions instead of geometric ones.