中文摘要：

在三维CAD系统中，不论是自下而上还是自上而下的设计模式，对于组成装配体的不同零件之间仅能实现一对一的尺寸参数关联。提出了一种基于UG装配体装配特征自动识别的方法，分析了装配特征的各种定义和表达方法。建立了基于配合尺寸链的相关零件的尺寸关联，实现了逆向参数化设计，并在UGNX．3．0环境开发了一个实现该功能的独立模块。

英文摘要：

In 3D CAD systems, one-to-one dimension relation among assembly-parts is only realized no matter the design mode is top-down or bottom-up, A method of automatic recognization is presented based on assembly feature in UG, and the assembly features＇ definitions and expressional models is analysed. The interrelated dimension relation is established based on fit dimension chain, The converse parametric design is realized, besides a module in UG NX3.0 with UG/OPEN API is developed.