An integrated intelligent machining system for axisymmetric parts using PC-based CAD and CAM software packages

Machining process planning involves the formation of a set of directions describing the machining operations required to transform raw stock into a finished part. Conventional process planning, performed manually, relies on the knowledge and competence of an experienced process planner and tends to be time consuming and error prone. In the past two decades, much effort has been spent on improving process planning by utilizing the power of a computer to emulate the capabilities of an experienced planner. During the same period, computer-aided design (CAD) and computer-aided manufacturing (CAM) software has been developed to enhance design productivity and to assist the NC code generation facets of the machining process. The entire planning process may be automated be integrating CAD and CAM using computer-aided process planing (CAPP). The research described in this paper outlines the design and development of an intelligent CAPP system integrating two commercial CAD and CAM software packages, Autocad and Mastercam.     

An integrated intelligent process planning system (IIPPS) for machining

A key component of computer integrated manufacturing (CIM) is computer aided process planning (CAPP). Process planning in machining involves the determination of the cutting operations and sequences, the selection of machine tools and cutting tools, the calculation of machining parameters, and the generation of CNC part programs. Industrial structures in Norway are defined as small and medium-sized companies. The important fact is how well these companies use high technologies and resources in order to improve their production efficiency, product quality, and company competition in international markets. The concept of an integrated intelligent system (IIS) is created for this purpose. A prototype system, the integrated intelligent process planning system (IIPPS), is described for machining; it was developed on the basis of an IIS and constructed using three levels of effort: (1) AutoCAD, (2) dBASE III and (3) KnowledgePro. The system may be utilized not only by a process plann ing engineer in a company, but also by students of mechanical or industrial engineering.     

Development of a collaborative CAD/CAM system

This paper presents the development of a collaborative CAD/CAM system (COCADCAM). COCADCAM extends an existing single-location CAD/CAM system to a multi-location CAD/CAM application so that two geographically dispersed CAD/CAM users can work together on a three-dimensional CAD-geometry coediting and CAD-related tasks collaboratively and dynamically. COCADCAM dynamically supports CAD data communication that are not available in traditional single-location CAD/CAM. The dynamic data communication is achieved through the development of networking algorithms and CAD/CAM functions in this paper. The networking algorithms based on UNIX Interprocess Communication (IPC), the Network File System (NFS), and a connection-oriented client and server model under the Transmission Control Protocol/Internet Protocol (TCP/IP) suite. The CAD/CAM functions included surface modelling, simulation of a milling toolpath, and post-processing of an NC program following collaborative CAD-geometry coediting, which are directly or indirectly supported by the Application Programming Interface (API) of the CAD/CAM software. The networking algorithms and CAD/CAM functions together can facilitate an environment for CAD-geometry coediting and related tasks such as design, analysis and manufacture. COCADCAM has been successfully implemented through local area network (LAN) and the Internet; a remote machining cell is also linked so that the generated NC program based on a coedited free-form surface can be used for the physical machining operation. The algorithm proposed by COCADCAM can be referenced for the extension of other single-location CAD/CAM systems to multi-location applications.     

A constraint-based system for product design and manufacturing

Constraint-based modeling is one of the most modern methods of product design. This paper illustrates a collaborative design and manufacture procedures based on a new approach under the constraint-based solver for product design. Such a method can be used for the collaborative computer-aided design/manufacture systems. A developing model will be constructed from conceptual design to tool-paths generation, and a case study of how to make a playing doll house was presented to verify this system.     

A computer integrated business control system for an SME

CIM technology — appropriate to the requirements of an SME specialising in the manufacture of mechanical actuation systems — was introduced as a low-cost phased implementation of software and hardware systems that exploit a database to integrate its design, manufacturing and business operations. The company's investments were based on a prudent assessment of its current and planned product range, existing and planned manufacturing facilities, the scale of its operations and business objectives. The impact of this manufacturing control system on the business operations of the company and its influence on the evolution of its product range are discussed.     

An integrated manufacturing planning assistant — IMPA

In this paper, we describe our development of a fully integrated manufacturing planning assistant (IMPA) system, which is able to: (1) interpret the finished part requirements directly from the designer's CAD systems or solid modelers without user intervention or special feature coding; (2) check the machinability of a designed part; (3) automatically generate a process plan, a tool path and an NC (numerically controlled) code, and (4) support interactive user modification of the resulting plans, tool paths and NC code. A demonstration version of the system was designed to provide automated assistance for the planning of machining processes on three-axes NC machine tools. The underlying architectural concepts and reasoning algorithms can be extended to more complex machines such as four-or-more-axes NC machines. CAD, CAE, and CAM including robotic, FMS (flexible manufacturing system) and NC machines are widely used in industry today. There is increasing interest in automation of factory control software Merchant, (1988); this includes automating the generation of the control programs — that is, in developing systems which will automatically produce the NC code for machining the part, given a model of the part, the shape of the raw material, and the machine specifications. With such systems, there are several difficulties in the manual preparation of an NC program code such as, long and tedious calculations, high risk of error in data preparation, etc., which need to be eliminated. This is a critical step toward the integration of CAD and CAM into a truly concurrent engineering and manufacturing environment.     

Development of a feature-based and object-oriented concurrent engineering system

Product information modeling is critical to the integration of mechanical CAD/CAM systems and to the implementation of a concurrent engineering system. This paper presents a recent development of a feature-based and object-oriented concurrent engineering system with its focus on a product information modeling technique implemented in the system. The technique was developed to capture product definition data including form features and their spatial relationships and to store them as an object-oriented information model during the design process. The paper also describes the implementation of the information modeling technique and its application to manufacturing process planning in an object-oriented environment.     

换热设备CAD系统智能化研究与开发

智能化是CAD／CAM系统的一个重要发展方向,文章以面向对象的思想和方法,采用人工智能语言C／C＋＋进行自上而下的模块化设计,把专家系统合理地运用到计算机辅助设计中,论述了在VC＋＋6．0开发环境下实现换热设备智能CAD系统的理论和方法。     

填料塔智能CAD专家系统的开发

为提高填料塔的设计效率和质量,采用面向对象思想的设计方法,对填料塔设备进行自上而下的模块化设计,同时把专家系统原理与CAD技术结合起来,实现填料塔智能CAD系统的开发．     

ARM数控系统高速处理串口数据的研究

数控实际加工先采用CAD/CAM软件画图,根据图形生成G代码,然后将G代码传送给数控系统来进行实际加工,实际一个工件生成的G代码相对ARM所拥有的存储资源而言很大,为了解决G代码传输速度与ARM数控系统代码处理速度不匹配问题.利用ARM的串口传送G代码,实现了ARM数控系统代码高速处理的同时,串口数据正确高速传送.经研究与实验,这种方法简单易行,在保证数据准确的前提下,提高了数据传输速度,提高了数控系统的加工效率.     

Integrated information processing for manufacturing—from CAD/CAM to CIM

The trend to integrated information processing (CAD/ CAM) leads to some new requiements. Consistent information processing in the presparation of production and in the production process demands an efficient division of labour between man and machine, the future-oriented engineer having to be especially prepared for this. In the present paper the resulting new demands on training and education are formulated. The essential features of integrated systems of automated information processing are characterized, and fundamental problems of the complex decision findings are explained from the angle of the manufacturing engineering. The paper is concluded by examples of solutions for the fully automated preparation and execution of production.     

A STEP-compliant process planning system for CNC turning operations

Over the last 50 years, there have been many significant enhancements in computer aided systems which have influenced the CNC technology. One area that can be considered as a bottleneck to these CNC enhancements, and in particular to interoperability in CNC manufacturing is G&M part programming (ISO 6983). To overcome this bottleneck, the new standard ISO 14649, known as STEP-NC, is being developed to provide detailed information on component design, process planning and machining strategies to manufacture parts for the next generation of intelligent CNCs. This standard forms the basis of a new paradigm shift in the CNC domain to support digital modelling of CNC manufacturing resources. The research in this paper aims to identify major issues and develop new software tools to demonstrate the feasibility of interoperable CNC manufacturing based on STEP-NC. Besides the literature review on recent research and development on STEP-NC, this paper proposes a Process Planning System (PPS) with surface roughness chosen as the process planning objective. PPS consists of five modules: program reader, process planner, STEP-NC CAD viewer, STEP-NC CAM viewer and program writer. The reader is responsible for interpreting the geometry and the manufacturing data from a STEP-NC text file into a stored data list. The process planner uses this data list and enables users to evaluate surface roughness based on a mathematical model. Through the STEP-NC CAD viewer, the part geometry can be shown and via the STEP-NC CAM viewer the toolpath can be verified. Finally, the writer converts the stored STEP-NC data of the system into an updated STEP-NC file. An example case study component is used to demonstrate the PPS and show the interfacing of the STEP-NC data.     

TolRM:面向三维CAD的公差建模系统

提出了面向三维CAD的公差建模系统T01RM的设计思想、系统结构、核心功能等．通过设计层次式的公差表示与基于类的公差类型定义,实现了公差与三维CAD系统的有机集成;研究了保证公差合理、完整、有效的评价方法．讨论了公差工程语义的解释方法,并给出了基于变动体的公差效果体现方法．为提高系统效率,分析了公差域的各种情况并对其进行预处理．经过较多的测试表明,TolRM具有较好的鲁棒性、实用性和先进性。     

计算机集成制造系统（CIMS）国际发展动态

ＣＩＭＳ（计算机集成制造系统）是世界上高技术开发项目之一．ＣＩＭＳ是涉及广泛技术领域的复杂系统，当前的研究课题覆盖了ＣＩＭ中方法学、技术和应用领域的部分内容．本文简要讨论ＣＩＭＳ的国际发展动态．     

双光子微细加工系统数据处理软件的实现

双光子微细加工技术是一项新型的三维微细加工技术。提出以STL格式作为典型CAD软件和双光子加工数据处理软件的中介格式,并以VisualC 6.0开发了基于MFC的该软件,由STL文件读入及显示、STL文件正确性检验、分层、轮廓线优化、扫描路径填充等模块组成。软件操作简单,使用可靠。     

Advanced material handling system for computer integrated manufacturing

A cordless linear synchronous motor (LSM) material handling system for CIM has been developed. The system incorporates a courier that moves without tether restrictions. This provides for an automated material handling system with improved travel and flexibility. The material handling system runs on an integrated reverse air bearing system which eliminates friction and backlash. The proposed system forms part of a manufacturing assembly, interacting with overhead manipulators and part feeders to form a comprehensive production system. The design and implementation of the cordless linear motor material handling system (MHS) is outlined and described in the paper.     

基于工作流管理的智能CAD集成系统

介绍了工作流管理的现状和产品数据管理技术，比较了知识处理与数据处理的特点，提出了一种以工作充为核心的智能PDM系统集成解决方案，通过在PDM系统中集成人工智能，使用STEP标准建立信息模型和数据交换，增强系统在信息和应用集成的过程中的适应性和开放性，提供基于Internet/Intranet的共享零件库和标准工程手册数据库，将工程设计和管理人员解放出来，可提高产品设计和资源利用率。