CAD／CAM集成系统中轴类零件CAPP专家系统的研制

当代在推进ＣＩＭＳ中，专家系统日益受到重视，本文论述了专家系统方法在自动生成零件加工工艺文件中的应用进行了研究和讨论，研制了一种创成式轴类零件ＣＡＰＰ专家系统－ＧＳＣＡＰＰ。该系统通过人机图形选单对话或与ＣＡＤ系统连接输入的方式输入少量信息（如零件结构，尺寸，精度及热处理方式等），即可在知识库的支持下自动生成完整的零件的加工工艺文件，系统运行简捷，可编工艺范围广，维护方便，输出的工艺文件符合工厂要     

Z－ESPP的实现机制

为了满足国内机械制造行业对ＣＡＰＰ系统日益增长的需求，以及ＣＩＭＳ集成制造环境对ＣＡＰＰ子系统的特殊要求，我们在ＳＵＮ－ＳＰＡＲＣ工作站和Ｘ－ＷＩＮＤＯＷ环境下用Ｃ语言开发了汉化版本的ＣＡＰＰ专家系统开发工具Ｚ－ＥＳＰＰ。本文简要介绍Ｚ－ＥＳＰＰ主要功能模块的实现机制，包括：用户界面子系统、零件输入子系统、数据库系统、专家系统开发工具、工序图与工艺卡片生成系统。     

Z—ESPP实现机制

为了满足国内机械制造行业对ＣＡＰＰ系统日益增长的需求，以及ＣＩＭＳ集成制造环境对ＣＡＰＰ子系统的特殊要求，我们在ＳＵＮ－ＳＰＡＲＣ工作站和Ｘ－ＷＩＮＤＯＷ环境下用Ｃ语言开发了汉化版本的ＣＡＰＰ专家系统开发工具Ｚ－ＥＳＰＰ。本文简要介绍Ｚ－ＥＳＰＰ主要功能模块的实现机制，包括：用户界面子系统、零件输入子系统、数据库系统、专家系统开发工具，工序图与工艺卡片生成和系统。     

基于特征的集成产品模型

一、集成产品模型随着计算机技术的日益发展,计算机辅助设计（ＣＡＤ）、计算机辅助工艺规程设计（ＣＡＰＰ）、计算机辅助制造（ＣＡＭ）、计算机辅助工程分析（ＣＡＥ）等系统也快速独立地发展起来,它们分别在产品设计自动化、工艺过程设计自动化和数控编程自动化等方面起到了重要作用。然而,人们越来越发现,采用这些各自独立的系统不能实现系统之间信息的自动传递和交换。例如,ＣＡＤ系统设计结果,不能直接为ＣＡＰＰ系统接受,若进行工艺规程设计时,还需要人工将ＣＡＤ输出的图样、文档等信息转换成ＣＡＰＰ系统所需要的输入数据…     

特征模型与CAD／CAM信息集成的研究

特征建模技术是实现ＣＡＤ／ＣＡＭ集成的核心，本文对建立在Ｉ－ＤＥＡＳ之上特征建模的研究为基础，针对板块类零件，提出了基于特征的集成模型总体结构和数据的组织方法，该模型以面为纽带，将零件的几何信息加工工艺信息有机地联系在一起，以便使ＣＡＤ的数据能方便地被ＣＡＰＰ、ＮＣ等后续环节所使用，从而为ＣＡＤ／ＣＡＭ的集成奠定基础。     

更广泛地应用,更快速地发展

计算机辅助工艺过程设计（ＣＡＰＰ， Ｃｏｍｐｕｔｅｒ Ａｉｄｅｄ Ｐｒｏｃｅｓｓ Ｐｌａｎｎｉｎｇ）的研究与开发始于２０世纪６０年代。最早提出ＣＡＰＰ技术的国家是前苏联，当时这一技术被称作“生产（工艺）准备系统”。具有里程碑意义的ＣＡＰＰ产品是设在美国的国际性组织ＣＡＭ－Ｉ于１９７６年开发的ＣＡＰＰ（ＣＡＭ－Ｉ' ｓ Ａｕｔｏｍａｔｅｄ Ｐｒｏｃｅｓｓ Ｐｌａｎｎｉｎｇ）系统。国内 ＣＡＰＰ的研究始于２０世纪８０年代初， １９８６年以后逐步形成了研发高潮。 经过二十多年的发展，国内外科研人员对ＣＡＰＰ技术进…     

基于CAD／CAPP并行设计的特征描述与操作

本文介绍了在作者开发的基于特征的ＣＡＤ／ＣＡＰＰ并行系统ＦＯＰＳ中,针对ＣＡＤ／ＣＡＰＰ并行设计的要求,对形状特征的表示处理策略。提出了基于加工的形状特征分类及体描述思想,并从一个新的角度认识处理形状特征,建立了基于特征描述的实体几何模型,提出了广义“凹孔”的特征认识概念及相应的“内环”处理技术,为有效地在设计过程中同时为ＣＡＰＰ系统提供必要的信息,便于进行零件设计的结构工艺性分析、评价及工艺规程     

CAD／CAM中的零件特征分析和成组技术

ＣＡＤ／ＣＡＰＰ／ＣＡＭ一体化中的关键技术是零件特征的确定。本文首先对零件特征进行分析，在分析的基础上对ＣＡＤ／ＣＡＰＰ／ＣＡＭ一体化技术中的成组技术及思想进行评价。     

CAD／CAM中的零件特征分析和成组技术

ＣＡＤ／ＣＡＰＰ／ＣＡＭ一体化中的关键技术是零件特征的确定。本文首先对零件特征进行分析，在分析的基础上对ＣＡＤ／ＣＡＰＰ／ＣＡＭ一体化技术中的成组技术及思想进行评价。     

CAPP系列讲座(二) 企业工艺设计基础及对CAPP系统提出的要求

目前强有力的市场竞争推动着技术和社会进步,使得制造业中各种技术得到空前发展。随着计算机在制造企业中的深入应用,计算机辅助工艺设计（ＣＡＰＰ）成为可能。因为ＣＡＰＰ系统的使用,不仅可以大大提高工艺规程设计效率和质量,而且保证了工艺设计的一致性、规范化,更重要的是工艺设计数据是指导企业物资采购、生产计划调度、组织生产、资源平衡、成本核算等重要的依据。然而,国内ＣＡＰＰ的发展和应用远远跟不上 Ｃ Ａ Ｄ、 Ｃ Ａ Ｍ、ＭＲＰＩＩ、ＰＤＭ等系统发展的步伐。 一、企业设计基础基本状况 工艺设计是优化配置工艺资源,…     

提高蒸气流量计量精度的算法及实现

为了充分利用气体流量测控网络资源，分析了一般带温度压力补偿的节流式流量计量算法在ｔ，ｐ波动较大时，不能很好地补偿气体密度的问题。提出了利用网络上层监测站进行数据查询和复杂计算，向下传输最新补偿参数的方法，去提高算法精度，给出了算法流程图，对算法进行了仿真，其效果令人满意。     

基于实例的回转类零件工艺路线决策方法研究

以回转类零件为例,利用基于实例的推理（ＣＢＲ）方法、专家系统方法和特征技术,构造了一套完整实用的基于实例的工艺路线决策方法。构造了一种相似性参数计算公式,论述了新零件与实例进行比较和匹配的策略和算法,以及实例工艺信息筛选和实例工艺线修正方法,在实例抽取过程中,新零件与实例的匹配信息被详细记录下来,使得以实例抽取为基础的实例工艺信息筛选和工艺线路修正算法变得相对简单并易于实现。     

An integration of feature recognition and process planning functions for turning operation

This paper deals with the development of a Computer Aided Process Planning(CAPP) system interfaced with CAD for turning operation. The developed system performs CAD interfaced feature recognition from part geometry database, and the decision procedures for process planning functions such as process and operation selection, machine tool selection, setup planning and operation planning.

The system runs under personal computer environments and AutoCAD is employed as CAD system and Turbo-C is used for the decision procedures. A case study is performed to evaluate the performance of the system.     

Application of genetic algorithm to computer-aided process planning in preliminary and detailed planning

Computer-aided process planning (CAPP) is an important interface between computer-aided design (CAD) and computer-aided manufacturing (CAM) in the computer integrated manufacturing (CIM) environment. A good process plan of a part is built up based on two elements: (1) optimized sequence of the operations of the part; and (2) optimized selection of the machine, cutting tool and tool access direction (TAD) for each operation. On the other hand, two levels of planning in the process planning is suggested: (1) preliminary and (2) secondary and detailed planning. In this paper for the preliminary stage, the feasible sequences of operations are generated based on the analysis of constraints and using a genetic algorithm (GA). Then in the detailed planning stage, using a genetic algorithm again which prunes the initial feasible sequences, the optimized operations sequence and the optimized selection of the machine, cutting tool, and TAD for each operation are obtained. By applying the proposed GA in two levels of planning, the CAPP system can generate optimal or near-optimal process plans based on a selected criterion. A number of case studies are carried out to demonstrate the feasibility and robustness of the proposed algorithm. This algorithm performs well on all the test problems, exceeding or matching the solution quality of the results reported in the literature for most problems. The main contribution of this work is to emerge the preliminary and detailed planning, implementation of compulsive and additive constraints, optimization sequence of the operations of the part, and optimization selection of machine, cutting tool and TAD for each operation using the proposed GA, simultaneously.     

基于CAPPFramework的CAPP专家系统研究与实践

论文基于863目标产品CAPPFramework(CAPP应用框架与开发平台),采用面向对象的信息分析与建模,介绍了面向对象的CAPP专家系统平台构建技术,包括面向对象的知识获取、知识表示、工艺决策推理,并介绍了该CAPP专家系统平台在2-5坐标平面结构件CAD/CAPP/CAM数控编程系统中的应用。     

基于CSCW的复杂产品协同工艺设计

专家系统在CAPP中的应用，使工艺设计系统变得日趋复杂。通过分析工艺设计过程中存在的问题，提出了一种基于CSCW的协同工艺设计与管理模式，使工艺设计由串行转为并行，有效提高了设计效率和系统柔性。     

工艺规划数据模型的构造

本文阐明计算机辅助工艺规划中一种新的数据模型，构造和表达一般性工艺规划进程，工艺规划数据模型包括产品模型和方法模型两个部分。产品模型表达产品在机械加工过程中各个状态；方法模型描述对产品进行加工的工艺方法和操作顺序。     

Integration of product design,process planning,scheduling, and FMS control using XML data representation

An efficient model for communications between CAD, CAPP, and CAM applications in distributed manufacturing planning environment has been seen as key ingredient for CIM. Integration of design model with process and scheduling information in real-time is necessary in order to increase product quality, reduce the cost, and shorten the product manufacturing cycle. This paper describes an approach to integrate key product realization activities using neutral data representation. The representation is based on established standards for product data exchange and serves as a prototype implementation of these standards. The product and process models are based on object-oriented representation of geometry, features, and resulting manufacturing processes. Relationships between objects are explicitly represented in the model (for example, feature precedence relations, process sequences, etc.). The product model is developed using XML-based representation for product data required for process planning and the process model also uses XML representation of data required for scheduling and FMS control. The procedures for writing and parsing XML representations have been developed in object-oriented approach, in such a way that each object from object-oriented model is responsible for storing its own data into XML format. Similar approach is adopted for reading and parsing of the XML model. Parsing is performed by a stack of XML handlers, each corresponding to a particular object in XML hierarchical model. This approach allows for very flexible representation, in such a way that only a portion of the model (for example, only feature data, or only the part of process plan for a single machine) may be stored and successfully parsed into another application. This is very useful approach for direct distributed applications, in which data are passed in the form of XML streams to allow real-time on-line communication. The feasibility of the proposed model is verified in a couple of scenarios for distributed manufacturing planning that involves feature mapping from CAD file, process selection for several part designs integrated with scheduling and simulation of the FMS model using alternative routings.     

Computer-assisted preoperative planning (CAPP) in orthopaedic surgery

Computer-assisted preoperative planning (CAPP) is a complex approach to planning a surgical treatment. It includes computer-assisted design (CAD) principles, expert knowledge utilization and facilities for decision making process support. The CAPP system uses actual patient data and calculates instructions in real dimensions for performing a particular operation on a particular patient. Our first CAPP application was preoperative planning of corrective osteotomy of a malunited fracture at the distal end of the radius. The application was based on the construction of three-dimensional wire models from only two orthogonal projections of objects (two orthogonal X-rays of affected and healthy wrists). On these wire models, an operation of the affected hand was simulated until the best fitting of the models was achieved. The use of real dimensions in computer calculation was crucial because the numerical output was used as a surgical treatment guideline. The results obtained in a group of 33 patients were excellent when compared with the results reported in the literature.