冲压模具初始设计KBS系统研究

【作者】 马闯；

【导师】 钟志华； 李光耀；

【作者基本信息】 湖南大学 ， 车辆工程， 2002， 硕士

【摘要】 利用计算机仿真技术动态地模拟冲压过程是冲压模具设计手段的一个飞跃发展。但是，在仿真前仍需工艺专家给出初始工艺参数作为仿真的起点，初始设计的好坏直接影响到成型模拟周期的长短，这样就造成了仿真过程对专家的依赖。本文正是为解决这样的问题，研究冲压模具初始设计KBS系统，代替冲压模具的纯人工初始设计，涉及到的关键问题包括如下几个方面： (1) 研究面向对象技术和对模具设计知识的分析及其在冲压模具初始设计KBS中的应用。提出了设计知识类表示模具初始设计知识的方法，用类的结构对知识自然地进行分类，并把知识与推理封装在一个类对象中，使对象成为知识库系统中的一个有机整体。 (2) 研究面向对象的知识库结合数据库技术的实现。根据对模具设计知识的总结，设计三种形式子知识库，即数表型、公式型、规则型，实现知识的逻辑存储。 (3) 通过设计面向对象以及面向过程两个相互作用的推理机实现推理，提高推理效率。面向对象的推理机实现对对象的检索定位，面向过程的推理机采用广度优先的正向搜索策略。 除上述内容外，为了有良好的人机交互性，本文在应用软件界面、交互式的人机接口和设计思路等方面做了大量工作。 基于上述研究，本文开发出针对弯曲件的模具初始设计KBS系统，该系统的开发对降低成型模拟过程中对专家的依赖，加速CAD／CAE／CAM一体化进程具有积极意义。更多还原

【Abstract】 The application of computer simulation of sheet metal forming process is a milestone in the development history of tool design techniques. But, the simulation still needs initial process parameters given by experts, which results in dependence on the experts inevitably. This paper aims at solving the problem mentioned above and developing a knowledge-based system for initial tool design of sheet metal forming. The following aspects are concerned:(1) Analysis of the object-oriented method and the tool design knowledge and its application in knowledge-based system for initial tool design of sheet metal forming. The concept of "knowledge class" is used, in which the tool design knowledge is represented in two forming: static knowledge and dynamic knowledge.(2) The realization of knowledge base integrated with database technology. The knowledge base comprises three sub-bases: tables, formulae and rules.(3) The inference engine composed of object inference and process inference engine. The object inference not only accomplishes the index and location tasks, but also has the function of controlling the process inference engine. The process engine completes the task executed by wide preference top-down reasoning method.Much of work has also been done for improvement of user-friendship of the KBS system.Based on the above studies, a knowledge-based system specialized in bending tool design is developed. This KBS system should be helpful in minimizing the dependence on the expertise hi simulation process.更多还原