基于装配特征偶的设计意图建模方法

Modeling Assembly Design Intent Based on Assembly Feature Pair

产品建模是影响制造企业竞争力的关键因素之一,包括零件建模和装配建模两个方面。在当前的计算机辅助设计系统(Computer-aided design,CAD)中,当设计一个零件时,设计者知道该零件将如何与他零件配合,但这一信息(装配设计意图)并未存储在零件模型中,因此需要在装配建模阶段通过大量地拾取几何元素、输入约束命令进行重复表达,工作量巨大、操作过程繁琐。为减轻上述问题,首先对装配设计意图的表现形式和传递过程进行系统分析,明确其建模的基本原理;其次,基于前期发展的装配特征偶(Assembly feature pair,AFP)概念,对装配设计意图涉及的配合结构和行为进行系统建模;最后,阐述在产品建模和装配过程仿真中依托AFP传递设计意图的模式,并通过实例验证基于AFP描述装配设计意图、实现两个阶段集成的可行性。该方法可为装配设计意图的一致性、简化传递奠定基础,丰富并发展现有CAD建模理论和技术体系。

Product modeling is one of the key factors influencing industrial completeness, including part modeling and assembly modeling in the mainstream computer-aided design(CAD) systems. However, when creating a part solid model at part modeling stage, the information of how it will interface with other parts assembly design intent(ADI), which is known by the designer, is not stored in the part model. As a result, the ADI has to be implemented again at assembly modeling stage, through numerous tedious and error-prone operations such as picking up geometry elements and inputting constraint commands. To alleviate these problems, firstly, the transmission process of the ADI in product modeling is systematically analyzed, revealing the principle of ADI modeling. Then, a previously developed concept of assembly feature pair(AFP) is used to model the abstract ADI(consisted of mating structure and mating behavior) merely known by the designer. Finally, the paradigm of transmitting ADI in product modeling and assembly process simulation based on AFP is demonstrated, and a gear bump sample is analyzed to validate the feasibility of modeling ADI and integrating the two stages through AFP, indicating that the proposed method may have the potential to make the ransmission of ADI in a consistent and simple way, and further to enrich and facilitate the development of CAD modeling theory and technology systems.