A framework for collaborative top-down assembly design

This paper presents a new system framework for collaborative top-down assembly design. Different from current computer-aided design (CAD) systems, the framework allows a group of designers to collaboratively conduct product design in a top-down manner. In our framework, a multi-level and distributed assembly model is adopted to effectively support collaborative top-down assembly design. Meanwhile, fine-granularity collaborative design functionalities are provided. First, the coupled structural parameters involved in the distributed skeleton models of the product can be collaboratively determined by the correlative designers based on fuzzy and utility theory. Second, agent based design variation propagation is achieved to ensure the consistency of the multi-level and distributed assembly model during the whole design process. Third, collaborative design of assembly interfaces between the components assigned to different designers is supported. The prototype implementation shows that our framework works well for supporting practical collaborative top-down assembly design.     

Trust-based access control for collaborative systems

In distributed, heterogeneous and network-connected collaborative environments where resources are provided to diverse unknown users for their applications, it is necessary to define access control for resources. Access control for such systems is defined as the ability to authorise or repudiate access to resources by a particular user. Traditional access control solutions are inherently inadequate for collaborative systems because they are effective only in situations where the system knows in advance which users are going to access the resources and what are their access rights so that they can be predefined by the developers or security administrators, but in collaborative systems the number of users as well as their usage on resources is not static. Targeting collaborative systems, a fine grained, flexible, persistent trust-based model for protecting the access and usage of digital resources is defined in this paper using radial basis function neural network (RBFNN). RBFNN classifies the users requesting the resources as trustworthy and non-trustworthy based on their attributes. RBFNN is used for classification because of its ability to generalise well for even unseen data and non-iterative method employed in its training. A proof of concept implementation backed by extensive set of tests on the real data collected for one such collaborative systems, i.e. Enabling Grids for E-Science grid demonstrated that the design is sound for collaborative systems where access of resources are provided to large and unknown users with their variant set of requirements.     

分布式同步协同包装纸盒CAD/CAM系统的设计与实现

采用Java技术开发了基于Web的分布式同步协同包装纸盒CAD／CAM系统．研究了纸盒CAD／CAM系统的体系结构、系统功能的分配、分布式同步协同设计、并发控制、协同感知、负载均衡、3D可视化技术、参数化设计以及系统安全性的保证等关键技术．     

基于网格技术的分布式数据库OLAP应用

引入网格技术来处理分布式数据库,在网格环境下访问已有数据库,提供一个访问不同数据资源的统一接口,并在此基础上将已有的数据库动态地组成一个虚拟数据库完成某一特定任务。用OLAP工具进行数据的预测、分析和决策。最后以某市工商系统分布式业务数据为基础,设计了网格环境下数据集成的原型架构——GOLAPS,并采用模块化的设计方法,以网格服务的形式加以实现,服务之间通过标准的接口进行通信。     

面向普适环境的协同设计框架研究

提出了一种面向普适环境的协同设计框架。该协同设计框架在现有分布协同对象计算技术和网格服务的基础上,引入了普适环境“随时随地”和“透明”的思想,巧妙地把协同设计技术融入第三代计算环境中。该文讨论了普适计算的相关理论,也涉及了网格计算的相关技术。并且建立了第三代计算环境下分布式协同设计模型。该框架能够很好地利用各种网络资源,随时随地的进行产品设计开发。最后简要介绍该框架在在自主开发的HUST-CAIDS中的初步应用。     

网络化产品协同设计的理论与实践

网络化产品协同设计是实施先进制造的重要支撑技术,该文在分析其研究现状和特点的基础上,提出了基于中介代理的联邦式协同机制和基于约束松弛的协同递归式设计模式,为分布式协同设计的有效运作和基于知识的协同求解提供了一种理论依据。设计并开发了相应的网络化协同设计支持系统——CoDesignSpace,给出了系统的体系结构和实施方法。     

A grid-based collaborative system for vehicle crash safety design and its application based on LAN

Car manufacturers and their suppliers are usually geographically dispersed, heterogeneous characters of various resources. To solve the resource sharing and data security problems in vehicle collaborative design environment, grid technology and Computer Supported Collaborative Work (CSCW) technology are integrated. This paper proposes a collaborative design system for vehicle crash safety design based on grid technology that is conformed to the OGSA framework, and explains how the grid middleware VEGA contributes to make collaboration more efficiently. Web services about the functions in this collaborative system are realized based on VEGA. Design principles and methods based on the FE analysis tool LS-DYNA are also presented. Finally, a test bed is built based on LAN and a case of a carmaker collaborating with a seat supplier is presented.     

基于网格服务的协同设计平台的设计

为充分利用产品设计合作企业的资源和个体优势,更好地支持企业产品协同设计,从协同设计平台功能需求出发,研究了基于网格服务的协同设计平台的体系结构、资源集成与共享、网格服务实现、网格门户实现等关键技术,构建了基于网格服务的协同设计平台.该平台通过开放网格服务框架,实现了合作企业软件集成和设计资源共享,提高了资源的利用率和产品设计的质量.最后通过机械产品协同设计表明了该平台的有效性.     

A multi-agent and cloud-edge orchestration framework of digital twin for distributed production control

The demands for mass individualization and networked collaborative manufacturing are increasing, bringing significant challenges to effectively organizing idle distributed manufacturing resources. To improve production efficiency and applicability in the distributed manufacturing environment, this paper proposes a multi-agent and cloud-edge orchestration framework for production control. A multi-agent system is established both at the cloud and the edge to achieve the operation mechanism of cloud-edge orchestration. By leveraging Digital Twin (DT) technology and Industrial Internet of Things (IIoT), real-time status data of the distributed manufacturing resources are collected and processed to perform the decision-making and manufacturing execution by the corresponding agent with permission. Based on the generated data of distributed shop floors and factories, the cloud production line model is established to support the optimal configuration of the distributed idle manufacturing resources by applying a systematic evaluation method and digital twin technology, which reflects the actual manufacturing scenario of the whole production process. In addition, a rescheduling decision prediction model for distributed control adjustment on the cloud is developed, which is driven by Convolutional Neural Network (CNN) combined with Bi-directional Long Short-Term Memory (BiLSTM) and attention mechanism. A self-adaptive strategy that makes the real-time exceptions results available on the cloud production line for holistic rescheduling decisions is brought to make the distributed manufacturing resources intelligent enough to address the influences of different degrees of exceptions at the edge. The applicability and efficiency of the proposed framework are verified through a design case.     

Role-based viewing envelopes for information protection in collaborative modeling

Information security and assurance are new frontiers for collaborative design. In this context, information assurance (IA) refers to methodologies to protect engineering information by ensuring its availability, confidentiality, integrity, non-repudiation, authentication, access control, etc. In collaborative design, IA techniques are needed to protect intellectual property, establish security privileges and create ‘need to know’ protections on critical features. Aside from 3D watermarking, research on how to provide IA to distributed collaborative engineering teams is largely non-existent.This paper provides a framework for IA within collaborative design. It is based on a technique we call role-based viewing, which is achieved through integration of multi-resolution geometry and security models. In this way, 3D models are geometrically partitioned, and the partitioning is used to create multi-resolution mesh hierarchies that obscure, obfuscate, or remove sensitive material from the view of users without appropriate permissions. This approach is the basis for our prototype system FACADE (the Framework for Accesscontrol in Computer-Aided Design Environments), a synchronous multi-user collaborative modeling environment. In FACADE, groups of users work in a shared 3D modeling environment in which each user's viewing and modeling privileges are managed by a central access control mechanism. In this manner, individual users see only the data they are allowed to see, at the level of detail they are permitted to see it.     

A knowledge intensive multi-agent framework for cooperative/collaborative design modeling and decision support of assemblies

Multi-agent modeling has emerged as a promising discipline for dealing with decision making process in distributed information system applications. One of such applications is the modeling of distributed design or manufacturing processes which can link up various designs or manufacturing processes to form a virtual consortium on a global basis. This paper proposes a novel knowledge intensive multi-agent cooperative/collaborative framework for concurrent intelligent design and assembly planning, which integrates product design, design for assembly, assembly planning, assembly system design, and assembly simulation subjected to econo-technical evaluations. An AI protocol based method is proposed to facilitate the integration of intelligent agents for assembly design, planning, evaluation and simulation process. A unified class of knowledge intensive Petri nets is defined using the O-O knowledge-based Petri net approach and used as an AI protocol for handling both the integration and the negotiation problems among multi-agents. The detailed cooperative/collaborative mechanism and algorithms are given based on the knowledge objects cooperation formalisms. As such, the assembly-oriented design system can easily be implemented under the multi-agent-based knowledge-intensive Petri net framework with concurrent integration of multiple cooperative knowledge sources and software. Thus, product design and assembly planning can be carried out simultaneously and intelligently in an entirely computer-aided concurrent design and assembly planning system.     

基于Web Service的分布式协同CAD系统框架

采用XML定义了基于Web Service分布式协同CAD系统框架中服务器端和客户端之间特征操作和协同设计的通信协议．该系统以特征为基本协同设计单元，服务器端和客户端之间采用增量式特征信息交互，降低网络流量，增强了系统的响应能力．由于系统基于Web Service构造，因此可以支持跨异构平台协同设计，原型系统的应用表明，该系统可以较好地支持分布式条件下的协同设计。     

Research on an active knowledge push service based on collaborative intent capture

The quality of a knowledge service influences the quality, efficiency and innovation of product conceptual design. Existing approaches lack intelligence and individuation when providing a knowledge retrieval service via rules and cases. In this paper, we propose a framework of an active knowledge service based on collaborative intent capture to assist product conceptual design. First, a collaborative intent capture model is constructed through the study of the expression and capture of collaborative intent; second, a framework and a process of active knowledge push based on collaborative intent capture are designed after analyzing the method of knowledge resources acquisition based on the constraint satisfaction theory. Finally, match algorithms for text content are studied. Based on the above research achievements, a prototype system of a collaborative design and active knowledge service platform (C-AKSP) has been developed for providing a knowledge service and assisting product conceptual design. An example, the conceptual design of a machine tool spindle system, is used to validate the proposed theories for the model, the framework and the algorithm. As a result, C-AKSP can provide a superior knowledge service that meets the designer's knowledge needs.     

Feature-based design in a distributed and collaborative environment

In this paper, a client/server framework has been developed to enable a dispersed team to accomplish a feature-based design task collaboratively. A manipulation client+modelling server infrastructure has been proposed to facilitate consistent primary information modelling for multiple users and adaptability of the system. Based on feature-to-feature relationships, a distributed feature manipulation mechanism has been proposed to filter the varied information of a working part during a co-design activity to avoid unnecessary re-transferring of the complete large-size CAD files each time when any interactive operation is imposed on the model by a client. In the distributed environment, a design task and the engaged clients are organised and connected through working sessions generated and maintained dynamically with a collaborative server. The environment is open to downstream manufacturing analysis modules to achieve distributed concurrent engineering.     

A CAE-integrated distributed collaborative design system for finite element analysis of complex product based on SOOA

Large-scale finite element analysis of complex product needs a wider support from external CAE resources. This paper proposes a method of the distributed concurrent and collaborative design in the distributed intelligent resources environment to use Web-based extended manufacturing resources for product development. The CAE-integrated distributed collaborative design system architecture and enabling techniques are presented. Distributed CAE service resources on the Internet are achieved through Jini^TM and service object-oriented architecture technologies. These CAE software tool resources are encapsulated as service providers in the system. A case study of railway bogie development is presented, and the Pro/E, HyperMesh, Ansys and HumanExpert service providers dynamically invoked and integrated as a temporary service federated environment with no need to know the exact location of a provider beforehand, flexibility can be well achieved, and collaborative design in the system can be implemented in the distributed dynamic environment. Compared with the traditional design system, some preliminary results indicate this architecture can shorten the cycle of service exchange, and strongly support concurrent and collaborative design of the complex product.     

A time-aware Bayesian approach for optimal manufacturing service recommendation in distributed manufacturing environments

With the growing emergence of distributed collaborative manufacturing systems, the utilization of service-oriented manufacturing to offer seamless access to a variety of complex, distributed and dynamic manufacturing resources has become a challenging issue. This paper presents a novel time-aware probabilistic Bayesian approach for recommending a few optimal manufacturing services based on the user preference for an initial manufacturing service. The Bayesian approach operates over a comprehensive, formal representation of manufacturing services, which adds the time-aware probability of satisfied service execution in manufacturing service ontology to take into account the statistical nature of the dynamic manufacturing environment. The Bayesian approach is useful because it infers a few top ranked hypotheses of manufacturing service that have the largest probability as the optimal selection in a specified context of user preference. A prototype system is built and validated with an illustrative example from manufacturing industry to demonstrate the feasibility of the proposed approach for optimal service recommendation.     

基于SOA网格访问控制模型的研究

信息网格是未来分布式计算的主要发展方向,网格安全不仅是网格推广应用的前提,也是计算网格中的一个核心问题,随着面向服务(SOA)的网格技术的发展和应用,如何解决访问资源的授权成为一个关键性问题,本文通过对当前授权系统的概述和分析,设计了一种面向服务的网格授权系统.     

基于资源共享的柴油机行业异地协同工作技术

基于柴油机行业提出制造业的异地协同工作模型,并提出基于资源共享的协同设计思想和协同制造模型.建立动态BOM和动态工艺路线,用邻接矩阵理论来解决协同企业之间的动态工艺路线问题.通过实例反映了协同企业之间的信息和资源共享.     

基于仿真网格的SBA协同环境研究

为解决"基于仿真的采办 (SBA) "协同环境中存在的诸如资源共享困难、互操作性差等一系列问题,实现SBA系统中工具、技术、人和过程的集成;通过研究SBA协同环境体系结构,分析仿真网格体系结构及其所具有的资源共享、协同工作、基于统一的开放技术标准等技术特性,设计了面向应用的基于仿真网格的SBA协同环境体系结构;该体系结构具有多项技术优势,可以很好地解决SBA协同环境实现中面临的各种问题,满足SBA协同环境的设计要求,为SBA协同环境原型系统的实现提供框架支持;最后展望了基于仿真网格的SBA协同环境的应用前景.     

Preliminary design and manufacturing planning integration using web-based intelligent agents

Software agents have been increasingly used in the product and process development in industry over the past years due to the rapid evolvement of the Internet technology. This paper describes agents for the integration of conceptual design and process planning. Agents provide mechanisms to interact with each other. This mechanism is important since both of those processes involve negotiations for optimization. A set of design and planning software agents has been developed. These agents are used in a computer-based collaborative environment, called a multi-agent platform. The main purpose of developing such a platform is to support product preliminary design, optimize product form and structure, and reduce the manufacturing cost in the early design stage. The agents on the platform have access to a knowledge base that contains design and planning rules. These rules are derived from an analysis of design factors that influence process and resource planning, such as product material, form, shape complexity, features, dimension, tolerance, surface condition, production volume, and production rate. These rules are used by process planning agents to provide process planners with information regarding selecting preliminary manufacturing processes, determining manufacturing resources, and constructing feedback information to product designers. Additionally, the agents communicate with WEB servers, and they are accessible by users through Internet browsers. During performing design and planning tasks, agents access the data pertinent to design and manufacturing processes by the programming interfaces of existing computer-aided design (CAD) and manufacturing system. The agents are supported by a developed prototype agent platform. The agents and the platform enable the information exchange among agents, based on a previously developed integrated design and manufacturing process object model.