基于STEP-NC智能数控系统的研究

论述了基于STEP—NC智能数控系统的工艺流程，提出一种基于多智能体STEP—NC智能数控系统的体系结构，整个系统由解释Agent、工艺规划Agent、监控Agent和决策Agent等12个不同功能的Agent组成，各Agent之间相互协作，共同实现STEP—NC智能数控系统的各种功能。以系统中的两个核心模块——解释Agent和工艺规划Agent为例，阐述了其实现的具体方法。给出了开发完成的原型系统部分功能模块。提出的构建智能型STEP—NC数控系统的策略和方法，对深入研究基于STEP—NC智能数控系统具有一定参考作用。     

Tool deflection error compensation in five-axis ball-end milling of sculptured surface

Manufacturing of aircraft structural parts have the characteristics of complex process, large variety, small batch, and frequent change of production status. In order to shorten lead time and reduce cost, high-efficiency communication and collaboration among manufacturing departments are required. However, in the existing research literature, tool/fixture design, manufacturing simulation, and online machining process monitoring are not fully taken into account for collaboration. In order to address these challenging issues, this paper proposes a collaborative manufacturing framework based on machining features and intelligent software agents. The components of the proposed framework include a machining process planning agent, a numerical control (NC) programming agent, a simulation and verification agent, a tool/fixture design agent, a cost estimation agent, a production management agent, and an online machining process monitoring agent. Machining features are used as information carrier for communication and collaboration among these agents. This paper particularly focuses on the collaboration between tool/fixture design and NC programming, as well as the collaboration between online machining processes and related departments. The proposed approach has been implemented through a prototype system and tested in a large aircraft manufacturing enterprise with some very promising results.     

A Schema for Flexile Equipment Control in Manufacturing Systems

In this work a methodology is proposed for increasing the flexibility of the control software of Flexible Manufacturing Systems (FMSs). This greater flexibility is required due to factors such as uncertain product demand, uneven distribution of shop load, and machine or cutting tool unavailability. In the proposed framework the following modules were developed: (a) an automated process planning module which generates non-linear process plans for a given part, considering the shop floor resource availability; the non-linear plans include both material handling and material processing information; (b) a planning module that linearises the process plan aiming at minimising the total manufacturing time of the parts; (c) a NC program generation module, which generates the NC program for the chosen CNC machine(s). In order to increase the flexibility of the control software even more, a resource model was devised and implemented, which provides the necessary resource information for the above modules. Each of these modules is described within this paper, and details about the part and process plan representation necessary for this implementation are also given. A case study is presented in order to show the capability of the methodology.     

智能重构制造控制系统集成框架

为提高制造控制系统的智能重构能力,扩展了IEC 61499基本功能块模型,提出了知识功能块新概念,并将其作为功能单元构建了智能重构制造控制系统集成框架.在阐述了智能重构与智能控制并行执行过程的基础上,提出了基于Web Services面向服务的制造控制系统软件体系结构,并采用统一化建模语言建模语言进行了系统设计.通过一个原型系统运行实例,验证了IEC 61499功能块标准、Web服务中间件和面向服务哲理在实现智能重构制造控制系统方面的有效性.     

基于BOM的IPD框架与实现

集成产品开发是解决产品开发中所有阶段所有职能部门的集成问题、改进产品开发过程的有效方法.提出以BOM为信息集成载体,建立基于BOM的IPD框架,将BOM的共享与传递贯穿于整个产品开发过程之中.进行了IPD框架内产品数据管理、生产工艺规划和制造资源计划模块中BOM的管理和集成设计.开发的软件系统已在企业得到实际应用.     

STEP-NC compliant process planning of additive manufacturing: remanufacturing

Additive manufacturing is becoming one of the key methods for reproducing repair sections in remanufacturing processes. The major advantage of using additive processes is to minimize production time and waste. However, the surface quality and shape accuracy are usually insufficient for the final product because the approximated representation format causes the accumulation of the error during the geometric operations of the process planning. This limitation is a barrier to utilize additive processes as finishing processes, such as general metal cutting. There is need to improve the final quality of parts obtained with additive manufacturing. In this paper, STEP-based numerical control (STEP-NC)-based process planning is applied to the additive manufacturing. ISO 14649 (STEP-NC) describes part programs with geometric data directly and also contains the information necessary for the intelligent process planning. This paper proposes the STEP-NC-based representation method of additive manufacturing and the series of geometric reasoning to automate the derivation of the repair section. The proposed representation has the benefits to provide a high accuracy for the final surface and to describe multiple materials. Topological data maintain low error during the series of process planning through the CAD-CAM-CNC chain. The proposed platform supports consideration of the process tolerance and comparison of the selected plan with alternative processes. In order to show the practical advantages, an analysis of the remanufacturing process is carried out. The case study of remanufacturing a pocket part is presented in order to validate the proposed process plan. The result of the case study shows the improvement in terms of automatic process planning and surface quality accuracy.     

[数据驱动的智能服务]面向凸轮轴磨削加工的智能决策云服务实现

Cloud service mode of intelligent decision in the camshaft grinding processes was established on the basis of analyses of characteristics in camshaft grinding processes and needs of intelligent decision-making under the cloud manufacturing mode. The overall framework of software for intelligent decision of the camshaft grinding processes was designed. Then the process intelligent decision-making software was developed, which included modules such as foundation integrated database, process knowledge base, process definition and decision-making optimization. Finally, the cloud service platform of intelligent decision for camshaft grinding processes was built and example verification was carried out,which realizes the cooperative development with intelligent decision and process data, a new way and the implementation approach are offered for efficient grinding processes of camshafts.     

[制造前沿]智能制造理论体系架构研究

从制造技术的发展变迁和面临的新挑战出发，分析了针对智能制造内涵及特征的认知发展过程，给出了对工业4.0时代智能制造的新认识，进而提出了智能制造理论体系总体架构，该体系架构由8个模块构成：理论基础、技术基础、支撑技术、使能技术、核心主题、发展模式、实施途径和总体目标。分别阐述了体系架构中的总体目标、核心主题、支撑技术和使能技术四大模块的具体内容，讨论了推进和实施智能制造的基本原则和技术路线，展望了未来制造的新形态和新特征。     

一种智能交通信号控制方法

提出了一种提高城市交通信号控制效率的新方法.首先对路面、车辆和交通控制系统作进行智能化建模,同时无线专用通信网络给车-路协作提供了可能.提出了交通控制系统的体系结构,以及基于机器学习的十字路口的智能管理机制,并进行了仿真研究.仿真结果表明,本文提出的方法可以比传统的交通管理系统提高效率约30%.     

基于自适应蚁群算法的工艺路线优化

针对计算机辅助工艺设计中最优方案选择,提出一种以制造资源更换率最低为目标的自适应蚁群优化方法(Adaptive ant colony algorithm,AACA)。通过分析零件特征,根据精度要求对制造特征进行分解,提出加工元概念。加工元被定义为特定的制造特征、加工阶段、加工方法、制造资源、装夹位置的集合,工艺路线的确定被转换为对加工元的优化顺序安排问题。以制造特征之间的几何位置约束,各加工阶段的先后顺序约束为基本元素,构造加工元优选约束矩阵,给出基于优选约束矩阵的加工元优选原则。在加工元优先顺序约束和可用制造资源的共同约束下,将缩短加工周期、提高加工质量和降低加工成本的综合目标表达为制造资源更换率最低,进行优化目标函数的数学建模。指出加工元优化排序可类比旅行商问题,并选择AACA进行优化求解。实例分析表明提出的方法可以可靠和有效地得到符合生产实际的工艺路线。     

基于诊断分析的生产线虚拟设计及其应用研究

利用离散事件仿真工具QUSET ,提出了基于诊断分析的生产线虚拟设计的体系结构、设计流程及其设计内容。详细研究了生产线的虚拟设备建模、虚拟工艺建模、虚拟控制建模等建模方法 ,并通过某生产线的实际工艺内容进行了生产验证 ,快速地诊断了其瓶颈工序 ,为生产线的设计、分析和调整提供了新的途径 ,为产品制造规划提供了有力的虚拟仿真工具 ,从而可以快速地响应市场变化和客户个性化生产需求     

工艺规划为核心的产品协同研发生产平台

为实现具有市场竞争力产品的高端研发,并具备较高的质量及成本控制能力,文中提出构建以工艺规划为核心的产品数字化研发生产平台的解决思路.平台框架包含计算机辅助设计、产品数据管理、计算机辅助工艺规划和协同制造模块;通过工艺与设计、生产两端的数据共享,实现设计、工艺数据和生产的高效协同;通过工艺规划方案的功能描述,展现了一个为...     

Developing an Integration Framework to Support the Information Flow Between PDM and MRP

Integrating various kinds of business application has attracted much attention in the business to business (B2B) market. The integration of the production planning functions and engineering design functions is an important area which has been addressed recently by some major enterprises. This paper proposes a methodology to support the integration of information flow between the applications of product data management (PDM) and manufacturing resource planning (MRP). A three-level structure including model development, model analysis, and system implementation was developed. An approach applying the concepts of semantic similarity to find the "common" objects used in different business applications was also proposed. These objects were used as a buffer for the information integration. In addition, a set of business rules was developed to govern the information flow between PDM and MRP. The proposed methodology has been implemented by integrating two commercial PDM and MRP software modules.     

产品质量智能预测控制研究

介绍了质量预测控制的研究现状,提出了基于质量特征参数序列的质量智能预测控制系统模型,分析了系统的稳定性.根据提出的系统模型利用动态神经网络对加工过程质量特征参数的变化进行了跟踪实验,效果良好.     

An integrated fixture planning system for minimum tolerances

Fixture planning is an important aspect of process planning. The steps involved in automatic fixture planning are manufacturing feature recognition, setup planning and fixture configuration planning. In the present work, an integrated setup and fixture planning system is developed for minimum tolerances at critical regions using a data exchanged part model as an input. A platform-independent STEP-based automatic feature recognition system that can recognize both design and manufacturing features, including intersecting features is implemented. An automatic setup planning module is developed for generating setup plans for complete machining of a given component. A fixture planning module is developed applying the criteria of uniqueness, stability, accessibility and tolerance minimization. A case study is presented to demonstrate the capabilities and integration between the various modules of the system.     

基于正则算法的工艺文件数字化技术研究

航发叶片工艺规程和数据信息采用二维CAD软件编写和绘制,生成的DWG工艺文件难以进行简便和高效管理。提出了叶片CAD工艺信息数字化的管理方法,首先,对叶片图纸工艺规程和数据信息进行关联性分析,采用最小二乘法完成图纸尺寸定位,根据坐标确定关键字位置,实现判断叶片工艺卡片类型;随后,判断识别需要的单元格工艺信息,利用正则算法进行文字排序,并识别处理特殊字符,调整后获得准确叶片工艺信息数据。实践结果表明,该方法能够快速、稳定地识别出CAD工艺文件中的工艺信息数据,为工厂实现智能制造数字化提供了图纸管理方法的应用参考。     

A flexible process information reuse method for similar machining feature

Dynamically changing machining conditions and uncertain manufacturing resource availability are forcing manufacturing enterprises to search advanced process planning in order to increase productivity and ensure product quality. As growing quantities of the three-dimensional process models are gradually applied, reusing the embedded manufacturing information in process models with less time and lower cost attracts a lot of attention. In this paper, a new flexible method is presented to reuse the existing process information based on retrieval of the similar machining feature. First, the three-level organization model is introduced to represent the process information; the machining feature which is seen as the parent layer carries the corresponding manufacturing information. To ensure accurately that the process information are obtained, the associated mechanism between the machining feature and process information is created. Second, an eight-node representation scheme is designed to represent the similar machining feature having same variations in topology and geometry. For accelerating similar feature retrieval, the extension-attributed adjacency graph and the topological relationship of the machining feature faces are built. Finally, some aircraft structural parts are utilized in the developed prototype module to verify the effectiveness of the proposed method. This method can be used as the basis for accumulation of the process information; it can promote the development and application of the intelligent process planning.     

Development of an intelligent agent-based AGV controller for a flexible manufacturing system

Automated guided vehicles (AGVs) are the most flexible means to transport materials among workstations of a flexible manufacturing system. Complex issues associated with the design of AGV control of these systems are conflict-free shortest path, minimum time motion planning and deadlock avoidance. This research presents an intelligent agent-based framework to overcome the inefficacies associated with the aforementioned issues. Proposed approach describes the operational control of AGVs by integrating different activities such as path generation, journey time enumeration, collision and deadlock identification, waiting node location and its time estimation, and decision making on the selection of the conflict-free shortest feasible path. It represents efficient algorithms and rules associated with each agent for finding the conflict-free minimum time motion planning of AGVs, which are needed to navigate unidirectional and bidirectional flow path network. A collaborative architecture of AGV agent and its different modules are also presented. Three complex experimental scenarios are simulated to test the robustness of the proposed approach. It is shown that the proposed agent-based controller is capable of generating optimal, collision- and deadlock-free path with less computational efforts.     

An industrial solution to object pose estimation for automatic semiconductor fabrication

To make control entities of flexible manufacturing systems (FMS) provided with characteristics of autonomy, cooperation, robustness, modularization, reconfiguration, maintainability, etc., we present in this paper a design method of autonomous and cooperative FMS control systems based on the latest agent standards of the foundation intelligent physical agent (FIPA). On the basis of discussing the concepts of the FIPA agent, the Java agent development framework (JADE) agent platform and FIPA specifications, the design method of FMS control systems is presented. Then the control software architecture and basic structure of a generic FIPA agent are designed. Finally, to demonstrate and validate the proposed design method, the prototyping FIPA agents have been implemented in MS 2000 Server/Professional Operating System, JADE and Java 6.0 Developer environments.     

Development of an Open Parallel Intelligent CNC Milling System. Part 1. System Structure

An open parallel intelligent CNC milling system is developed both in hardware and software. It is constructed as a hierarchical modular structure. An ontelligent controller module is devdloped based on the OSA bus using a PC, which os connected to the CNC main processor module through a dual-port memory so that parallel control can be realised. All the functional software modules are developed on a hierarchical parallel structure in a real-time multi-task operating system so that parallel processing can be realised.