A Case-Based Computer-Aided Process-Planning System for Machining Prismatic Components

This article deals with a process-planning system that uses case-based reasoning methodology. Briefly, case-based reasoning is an intelligent problem-solving technique which works by searching through a database for previously solved problems for one or more cases whose identifying features closely resemble the current problem. The case-based reasoning system used in this article to develop a process plan, typically consists of three modules, i.e. the part input and representation module, the case retrieval, and case adoption module. In this paper, new approaches have been proposed in all three modules. By incorporating a multiparametric and absolute-matching technique, the case retrieval module especially has become more powerful. A practical approach has been suggested in this research to compute the similarity between part input and case. An illustrative example is included to demonstrate the proposed system.     

从制造特征到夹具特征间接映射的中性特征模型研究

应用特征映射理论 ,探讨了将制造特征通过间接映射转换成夹具特征的方法 ,并且以VC ++6 .0和Ac cess2 0 0 0为开发平台 ,研制了具有中性特征信息库的映射子系统 ,它作为基于制造特征的夹具自动规划设计系统的一个重要组成部分已得到了验证。     

可重构电火花线切割CAD/CAM系统的研究

基于可重构的思想，根据电火花线切割加工CAD／CAM系统的特点，研究了系统的组件化结构和相关的组件开发技术，如组件模型实现的规范、组件的封装等，并在ACIS几何平台上进行了系统的可重构设计与研究。通过对应用系统已有功能进行封装，实现了组件化要求，在此基础上直持组件动态重用、更新和渐进开发，为以后系统参数化设计和智能加工工艺数据库技术的实现提供了支持。     

回转类零件基于 CAD/CAM 集成的工艺设计

主要讨论了回转类零件基于ＣＡＤ／ＣＡＭ集成的工艺设计方法，采用子工艺路线的设计方法，通过不同的子工艺路线的合理组合而构成了整个零件的加工工艺路线。在系统自动产生加工工艺路线的基础上，对计算机产生的结果加以修改和决策，可以得到符合实际加工情况的加工工艺。     

融合智能体和特征技术的焊接结构件CAPP集成系统研究

针对焊接结构件制造过程中涉及工种众多、工作环境异构的特点 ,提出一种融合智能体和特征技术的CAPP集成系统构造方法 ,使多工种 CAPP与 CAD、CAM信息集成的同时 ,其内部各工种 CAPP之间达成协调决策、集成与并行。在此基础上 ,建立了焊接结构件 CAPP的功能模型和系统集成框架。     

A Generative Feature-Based CAPP/CNC System for Hydraulic Manifold Blocks

A generative CAPP/CNC system for hydraulic manifold blocks is proposed to generate the process plan and the NC codes automatically by interfacing with a feature-based product model. A backward recursive method is used to determine the process operations for features, and an optimal searching algorithm is generated for sequencing the process operations. The sequenced process operations can be translated into the appropriate NC codes that can be recognised by a numerical control (NC) machine. In addition, a visual simulation for machining is built to check both the reliability of the NC codes and the feasibility of the design and manufacturing processes. The software is built using an object-oriented approach and it can be run under the Windows environment.     

一种基于特征的零件信息描述

目前大多数商用ＣＡＤ系统缺乏零件的制造信息，而且许多实验系统所进行的零件特征描述亦存在大局限性。提出一个以Ｉ－ＤＥＡＳ软件为基础的特征模型，对零件的几何信息和加工工艺信息都提供较完备的描述，以特定格式输出，并形成ＳＴＥＰ格式的中性方件，以便于ＣＡＤ／ＣＡＭ的集成。     

Inspection Planning Strategy for the On-Machine Measurement Process Based on CAD/CAM/CAI Integration

The objective of this research is to develop an effective inspection planning strategy for sculptured surfaces in the OMM (on-machine measurement) process. As a first step, effective measuring-point locations are determined to obtain optimum results for given sampling numbers. Two measuring-point selection methods are suggested in this study based on newly proposed CAD/CAM/CAI integration concepts: 1. By the prediction of cutting errors. 2. By considering cutter contact points to avoid the measurement errors caused by cusps. As a next step, the TSP (travelling salesman problem) algorithm is applied to minimise the probe moving distance. Appropriate simulations and experiments are performed to verify the proposed inspection planning strategy in this study, and the results are analysed.     

A review of knowledge-based expert systems for process planning. Methods and problems

This paper presents a review of knowledge-based expert systems for process planning and related methods and problems. It is based mainly on literature and partially on a questionnaire investigation carried out by the author. After a general presentation of process planning, the main problems are classified and the related methods and approaches for solving them are discussed. Finally, a list of fifty-two prototype systems is presented and their main characteristics are summarised in two tables.     

Form Feature and Tolerance Transfer from a 3D Model to a Set-up Planning System

Currently, most CAD systems, even the feature-based design systems which were developed for CAPP, cannot provide exact information about an object (e.g. dimensions and tolerances). Some feature-based design systems can provide product data directly or indirectly; however, most CAPP systems still do not have an interface with CAD systems. The product data required by CAPP systems usually has a specific format which is unique to the system. In a CAPP system, it is essential for set-up planning to ensure the precision of the machining processes. Therefore, it is necessary to develop an interface with CAD models, so that the part data file can be obtained directly from the CAD representation. This paper proposes an approach for integrating the set-up planning system with a feature-based CAD system. By using an object-oriented approach – Product Data Translator (PDT), the computer-automated extraction of geometry and complete tolerance information was achieved; and the automated generation of the tool approach direction was developed. RID=" ID=" <E5>Correspondence and offprint requests to</E5>: H.-C. Zhang, Department of Industrial Engineering, Texas Tech University, Lubbock, TX 79409&ndash;3061, USA. E-mail: hzhang&commat;coe.ttu.edu