Development of a Knowledge-Based Process Planning System for an Auto Panel

Challenges and pressures from the growing globalisation of markets have made automotive enterprises shorten the product development cycle time and reduce costs through the increasing use of mathematics-based tools and processes. In order to bridge the gap between experience-based design and science-based engineering, this paper establishes a knowledge-based process planning system to fully support auto panel die development and design automation. The framework of this novel system is proposed, and key issues, such as knowledge acquisition, knowledge representation and knowledge-based design are described in detail. The function model of the system is proposed to illustrate the architecture and functionality of the system. The system provides users with just-in-time access to the appropriate knowledge and information to reduce the search burden. A practical example is used to show the great advantage of the knowledge-based process planning system.     

基于知识的产品协同设计关键技术研究

CAD技术正向着开放、智能、分布和支持多用户协同设计方向发展。从产品生命周期的视角，讨论了基于封装的知识驱动协同设计系统的构建方法及其实现框架：详细研究了在基于知识的工程环境下实现知识驱动协同设计的关键技术。建立了知识驱动产品协同开发系统：断路器应用实例表明，知识驱动产品协同开发方法及其原型系统，能够有效地利用企业已有的知识资源，创造有竞争力的产品。     

Applying knowledge-based engineering to traditional manufacturing design

The paper outlines the development of a knowledge-based engineering (KBE) system for hot forging design using state–of–the–art technology and the Internet. The benefits of a KBE approach over a traditional design process are emphasized. The aim of the proposed KBE system is to integrate the hot forging design process into a single framework for capturing knowledge and experience of design engineers. The KBE application guides the design engineer through different stages of the design process enabling the generation of forgeable geometry from a component profile taking into account machine, material and forging company specific data, and design considerations.     

基于KBE的工程设计——理论、方法与实践

工程设计是一个知识驱动的创造性过程 ,KBE技术是促进工程设计智能化的重要途径。本文提出了 KBE的定义 ,分析、总结了 KBE与 CAD、专家系统等的区别 ;提出了基于 KBE的工程设计方法 ,并按设计知识的几何相关性 ,对知识处理的工具与方法进行分类 ;介绍了 KBE技术的应用现状 ,并以冲压模具设计为例建立了基于 KBE的设计系统框架。     

Intelligent Classification of the Drop Hammer Forming Process Method

Forging is a cost-effective way to produce net-shape or near-net-shape components. Forged components are used throughout the manufacturing sector in many different applications. Owing to the lack of an accurate process model, modern forging operations still largely rely on operator skills and experience. The expertise of skilled operators can help to develop a forging process model. However, these operators’ expert knowledge is accumulated through years of hands-on experience and is often biased towards their own heuristic. It is well known that accurate acquisition of this type of knowledge is challenging and time-consuming. In this paper, an innovative approach is developed to acquire forging process knowledge automatically by combining learning ability of the neural networks with the structured knowledge representation of rule-based systems. The approach is applied to the classification of process methods used in a type of impression-die forging, namely, drop hammer forming. Specifically, process data from an aerospace company’s production facility are collected. The data are processed and then used to train a back-propagation neural network. By analysing the connections and weights of the trained neural network, concise and intelligible rules are extracted. These rules can be used to allow a clearer specification of the drop hammer forming process plan and to shorten learning curves for novice operators.       

An Automated Process Planning and Die Design System for Quasi-Axisymmetric Cold Forging Products

This paper deals with an automated computer-aided process planning and die design system with which a designer can determine operation sequences even after only a little experience in process planning and die design of quasi-axisymmetric cold forging products by multistage former working. The approach is based on knowledge-based rules, and a process knowledge base consisting of design rules is built. Knowledge for the system is formulated from plasticity theories, empirical results and empirical knowledge of field experts. Programs for the system have been written in AutoLISP for AutoCAD with a personal computer. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM software, DEFORM and ANSYS, to form a useful package. The system is composed of three main modules and five submodules. The process planning and die design module considers several factors, such as the complexities of preform geometry, punch and die profiles, specifications of available multiformers, and the availability of standard parts. The system uses 2D geometry recognition and is integrated with the technology of process planning, die design, and CAE analysis. The standardisation of die parts for wheel bolts requiring a cold forging process is described. The system developed makes it possible to design and manufacture quasi-axisymmetric cold forging products more efficiently.     

A decision support system for rapid one-of-a-kind product development

A decision support system (DSS) is a specific class of computerized information systems that support decision-making activities. Such a system has become paramount in supporting manufacturing activities with the development of World Wide Web (WWW) technology in recent years. The research and development of a knowledge-based DSS dedicated to rapid one-of-a-kind products (OKPs), however, has, to the author’s knowledge, rarely been directly studied. This work presents a knowledge-based DSS for supporting decision-making activities in developing OKPs using broad knowledge base content. The underlying architecture of the proposed system is a system that manages and optimizes the data, information and knowledge in the product development process. A knowledge structure model is proposed in this paper, and a comprehensive set of expert knowledge and analytical/numerical methods are integrated into the system to automate intelligent decision-making. Case studies have shown that the knowledge-based DSS is able to help OKP companies develop new products more quickly by sharing optimization tools, information and knowledge to reduce possible errors and rework.     

Geometry-oriented knowledge-based system for preliminary process design of cold-forged parts

This paper presents an integrated architecture of a geometry-oriented knowledge-based process-design system (GEOPDE) for multistage cold forging of solid and hollow parts. It deals with the unit processes of upsetting, forward extrusion, backward extrusion and with combinations of these processes. By using the notion of group technology, the forging processes and forging part geometries are classified. With Prolog as the building tool, the inherited backward chaining reasoning was used for solving the deduction problems. The formation approach, such as “generate and test” and backtracking control strategy, was also employed for generating weighted alternative process plans. Using design rules, empirical formulae and material properties as integrated knowledge, the billet dimensions and the forging sequences are generated automatically once the product dimensions are given by the user. The developed system is a prototype expert system for the preliminary process design of cold-forged products for the forging industry.     

An integrated expert operation planning system with a feature-based design model

A framework of a knowledge-based expert operation planning system, TURNPLAN, is described. The system incorporates a feature-based part representation scheme to smooth the essential information flow from design intent to manufacturing practice. Its main functions initially consist of the determination of machining sequence, cutting parameters and cutting tools. To make this system a complete working module for full integration of CAD/CAM, its knowledge base has been further upgraded so that determination of work-holding methods, and generation of tool paths and the associated NC part programs, are included in the system. This integrated system is developed on a PC-based computer using PROLOG, which is found suitable in a batch-type job shop environment for industrial applications. A practical example is included to highlight certain features of the system and the paper concludes with implications for further research.     

基于知识的物流管理策略系统设计方法

针对企业生成物流管理策略的主观性、低适应性等情况,通过收集、检索和分析有用的知识,有效集成数据仓储、联机分析处理、多维数据库管理系统(MDBMS)和案例推理等技术,提出基于知识的物流管理策略系统(KLSS)设计方法,以帮助企业提高生成物流管理策略系统的效率和客观性。该系统的应用将降低物流管理成本,提高顾客满意度。     

A Two-Level Modelling Approach to Acquire Functional Design Knowledge in Mechanical Engineering Systems

Modelling as a means of knowledge acquisition has been proposed by some workers in artificial intelligence. In this paper the authors describe an approach using two-level knowledge modelling that employs the concepts of a functional model (extended FEBS model) and an object model to capture domain-specific functional design knowledge. The functional model serves as a basis for communication between domain experts and a knowledge engineer. The object model is used to bridge the gap between the functional model and an executable knowledge base. The approach is viewed as an important method for building a function-laden knowledge base that is useful for developing a knowledge-based functional design expert system. The proposed knowledge acquisition method is applied to an automatic assembly system for manufacturing electronic connectors to illustrate the general idea.     

新一代基于知识的工程系统

随着Interent技术与WWW技术，人工智能技术、数据挖掘与知识发现技术的发展，传统的智能设计已难以适应知识经济环境上新一代制造系统的要求，介绍了当今基于知识的工程的研究现状，指出了其发展方向；探讨了新一代基于Web的知识工程的关键技术，提出了一个基于Web的产品开发知识工程系统。     

Configuration-oriented product modelling and knowledge management for made-to-order manufacturing enterprises

In made-to-order (MTO) manufacturing enterprises (ME), product architectures are usually modularised and components standardised. Product configuration is a key technology for order realisation in MTO–ME and is a typical knowledge-based application. Through a configuration process, product modules or components are selected and assembled according to customer requirements. Product configuration relates to a great deal of knowledge that represents complexity relations among components or modules, such as configuration rules and assembly constraints. Traditional product modelling techniques are focused mainly on physical product modelling and geometric representation, which makes them insufficient to help in the product configuration process. This paper discusses configuration-oriented product modelling and knowledge management for MTO–ME. A general process of product configuration modelling is proposed. The configuration model represents a product family from which a specific configuration solution or product variant can be derived. Actually, configuration modelling is a process which captures and represents product knowledge. In this paper, product knowledge is organised and managed through a knowledge component (KCOM) that includes configuration rules and constraints. A KCOM-based product knowledge representation model is presented. Finally, a PDM system is extended to support product modelling and knowledge management for MTO configurable products .     

工程设计KBE系统(Ⅰ):概述

计算机辅助设计软件主要集中在辅助绘图功能 ,缺乏协助工程师提高设计效率的能力。本文提出了一种新的工程设计 KBE系统概念 ,并对其关键技术 (知识系统 ,知识获取 ,产品建模和分析技术 )进行了详细的论述。 KBE系统具有以下优势 :基于 AI技术建立与应用有关的设计环境 ;集成知识获取 (即数据挖掘 )的方法 ,使系统能够动态地建立各种领域知识。通过对注塑模模架设计过程的分析 ,给出了模架设计 KBE系统的数据流图和基本框架 ,使该系统在实际应用中能够有效地提高设计效率     

工程设计KBE系统(Ⅱ):知识处理技术

针对日益兴起的工程设计 KBE技术的研究和应用 ,本文对工程设计 KBE中的关键技术——知识处理技术 (知识表示和推理 ,知识获取 )进行了详细的论述 ,主要解决了基于框架 -规则的知识表示和推理 ,基于事例的推理以及神经网络的学习和推理在工程设计中的应用方法。该技术在应用中具有集成多种知识表示方法 ,能够充分利用工程领域知识的优势 ,并在注塑模模架设计中得到了有效的应用     

油轮快速设计与计量的智能化三维仿真开发系统的研究

针对油轮设计中容积计量的问题,从基于数据库的知识获取的角度对快速进行油轮容积数据的获取进行了研究,提出了三维计量的概念和在实际应用中的表现方式。采用面向对象的知识表达方法,利用Oracle数据库与UG三维造型软件相结合,研究开发了基于三维参数造型技术的支持油轮快速设计与计量的智能化三维仿真开发系统。系统由数据库知识系统模块和模型处理模块组成,可以自动生成油轮液舱的三维实体及相应的各倾角液体三维模型,大大缩短了设计检验周期。     

注塑模具模架选型中知识库与推理机连接技术的研究

在总结模架的基本知识及选型方法的基础上,利用KBS系统中的RBR推理方法实现注塑模具中模架的自动化设计,利用参数化设计技术生成模架系统的三维模型库,利用VB编程设计出系统操作界面,建立了注塑模具CAD专家系统中模架设计知识库和推理机,实现了推理机与知识库之间的连接。文章以实例介绍了模架知识库与推理机连接过程,KBS系统推理机通过合理调用知识库中的知识数据,实现模架的自动选型。     

锻件产品开发的设计仓库和智能知识供应研究

概述了基于Web、面向锻件产品开发的设计仓库的组成，提出了设计仓库的系统构架，并指出运用KDD方法进行智能知识供应的总体思路和实施模型，是对智能设计支持方法的一种丰富。此外详细分析了用户兴趣度矩阵的组成，并对相应的挖掘算法进行了研究。     

浅谈机械皮带锻锤与蒸汽-空气锻锤的能效

机械锻锤是一种依靠落下部分重力位能实现锻件变形的单工位锻造设备,投资建造成本低,结构简单,锻造生产能耗低,能交好,在珠三角地区应用广泛.为使锻造设备多样化,发挥机械锻锤的优势,降低锻造生产成本,通过研发,自行设计并主持制造了两台机械锻锤,生产中、小型锻件,设备使用两年多,运行良好.本文主要对自制1.5吨、2.5吨机械皮带锻锤及1吨、3吨蒸汽-空气锻锤的设计原理及其打击能量、能效进行比较分析.     

A solution for knowledge resources provider over the internet

Product development is complicated systematic engineering. The development of a successful product is achieved through cooperation between various design teams and utilisation of a number of design resources that exist in various disciplines, organisations and locations. As product complexity increases, product designers are required to collaborate with others to develop high-quality products. In this process, an effective solution is required from a knowledge resources provider for them to be able to acquire and share knowledge resources in various teams, locations, and domains. Based on the Internet, a solution for a knowledge resources provider, called a web-based product development support system (WPDSS), is proposed in this paper. The structure and implementation of the WPDSS system are both discussed in detail. Issues concerning development of the WPDSS system such as system structure, knowledge representation, and knowledge searches are investigated. Based on design of a rotor-bearing system of turbine machinery, a prototype of the WPDSS is developed to validate the feasibility of the proposed solution.