سیستم بهینه سازی برنامه ریزی عملیات مبتنی بر وب برای طراحی توزیع

In this paper, a process planning module, which can optimize the selection of machining resources, determination of set-up plans and sequencing of machining operations to achieve optimized process plans, has been wrapped as services and deployed in the Internet to support distributed design and manufacturing analysis. The module includes four intelligent approaches, and a Tabu search-based approach is explained in this paper to illustrate the optimization process. A Web-based prototype system has been setup for users to carry out visualization-based manipulations and process planning of design models by invoking the services remotely. The Web-based system has been integrated with a distributed feature-based design system, and the latter can generate design models and re-represent them in an XML representation based on VRML and attributes of features to provide the input of the former. Through effective utilization of the Web and Java technologies, this system is independent of the operating system, scalable and service-oriented, and can be used by a geographically distributed design team to organize concurrent engineering design activities effectively.

As one of the most popular Internet tools, the Web aims to provide a light-weight and an operating system-independent platform for users to search, browse, retrieve and manipulate information disseminated and shared remotely. Based on the Web, design models can be dynamically shared and updated in an Internet environment and conveniently accessed and manipulated by remotely located people from the design team, management, marketing, maintenance and customers for efficient design collaboration, design process monitoring, product pre-review and evaluation. Realizing the merits of the Web technology, researchers and developers have been actively exploring and developing Web-based design and manufacturing systems. Chen and Liang [1] proposed a Web-based system to integrate and share engineering information to support design and manufacturing activities such as domain investigation, functional requirement analysis, and system design and modelling. Functional modules in their system are wrapped and supported by CORBA for communication. The CyberCut system developed at the University of California at Berkeley [2] is a Web-based system integrating product design and process planning as a Java Applet program. The FIPER (Federated Intelligent Product EnviRonment) system [FIPER Project (www.fiperproject.com/fiperindex.htm)] [3] and [4] funded by NIST is to develop a new product design and analysis technology. The main objective of this system is to develop a Web-based distributed framework for design analysis and product lifecycle support based on component mechanisms and configurable workflow mechanisms. It can provide open and flexible capabilities to incorporate existing analysis and design tools/methods through Java-based wrapping mechanisms including Java Native Interface (JNI) and the FIPER SDK toolkit. Xiao et al. [5] developed the Web-DPR system as an infrastructure to support collaborative design and manufacturing. Based on the Java Remote Method Invocation (RMI) mechanism, agents and an event-based mechanism, the functional modules of the systems can be linked and coordinated effectively. Shyamsundar and Gadh [6] developed a new geometric representation named as AREP and a collaborative prototyping system based on this representation to perform real-time geometric modification for components/sub-assemblies in an assembly model. In the work of Choi et al. [7], Web service architectures were utilized to establish a new generation of distributed design and manufacturing platform based on XML schemas and a communication protocol SOAP (Simple Object Access Protocol) to provide a neutral data exchange format and effective capabilities in interoperability, integration and Internet accessibility of services. From these works, some common characteristics can be observed and an important trend is that application programs in product design, process planning, engineering analysis and simulation are embedded in a Web environment as Application Service Providers (ASPs) for remote invoking and manipulation to support distributed product design and development. This manner can bring many advantages such as avoiding complicated installations for individual computers, easily upgrading application modules and lowering the acquisition costs for Small and Middle Enterprise (SMEs) through renting services. In this paper, a Web-based system has been developed to support the establishment of a distributed design and manufacturing environment. The system can serve as a platform for distributed users to carry out process planning activities through optimizing the selection of machining resources, determination of set-up plans and sequencing of machining operations of a design model. Four intelligent approaches have been developed to solve this optimization problem, and a Tabu Search (TS)-based approach will be described to explain the process. The optimization module has been deployed in the Internet as Java Servlet-based application services based on a multiple-layer wrapping mechanism. Java Applet, Java2D and 3D technologies have been utilized in the system to develop a visualization-based manipulation environment of the design models and the optimization results. Through an XML-based data exchange format based on features and VRML, this system can exchange information with a distributed feature-based design system to form an integrated design and manufacturing analysis environment across the Internet.

In this paper, a Web-based process planning optimization system has been developed to support distributed design. The Web-based system provides a convenient platform for users to view and evaluate a design model effectively through dynamically invoking remote process planning optimization services. A TS-based approach is chosen and explained in detail to show the optimization process. Through a wrapping mechanism, the optimization modules have been developed as services located in the Internet for remote invoking. A distributed feature-based design system can generate design models in an XML-style feature representation to allow a Web-based system to perform feature-based viewing and manipulation. The main contributions of this work are summarized as follows: (1) By taking advantages of the effective utilizations of the Web and Java technologies, this system is independent of the operating system, scalable and service-oriented. The services located in the Internet can provide an effective manner for a designer to conduct a process planning optimization process to evaluate a design by him or others in a distributed design activity; and (2) A new XML-style feature representation has been proposed to carry out some feature-based visualisation manipulations in the Web-based system. This format incorporates the characteristics of VRML and features to support Web applications. The XML-based information representation enables the system to be effectively adaptable to meet the new development of the Internet technology such as the emerging Web-service technology. The multiple-layer architecture designed for wrapping the process planning services allows the system with the services to be extensible to integrate other legacy systems. The current system and services are based on the Java Servlet mechanism. With the development and popularity of some new Internet integration technologies such as the Web service, it is necessary to explore new alternatives to integrate the current functions and functional modules under the new system infrastructure. Meanwhile, the optimization algorithms will be enhanced and improved further. For example, the determination and optimization of the machining parameters for features and machining operations will be studied.