Collaborative Design Environment And Interaction Management Technologies Based On HLA

Complex products are often developed by multiple companies or departments with different domain knowledge in different locations. With the development of multimedia technology, communication technology and computer network technology, as well as the continuous introduction of new technologies, computer supported cooperative design radically changed the traditional product development mode of stand-alone operation. It has developed a collaborative design environment which supported human-human interaction and shared decision making, and become an important technical means of developing complex products and innovating design. Collaborative design strengthens the intercourse and cooperation between enterprise and department, takes full group advantage, improves the efficiency of product development, reduces the cost of product development and enhances the competition ability of enterprise.Domestic and foreign research and application related collaborative design focuses on the architecture, interaction technology and management techniques and so on. However, at present the two basic types of collaboration frameworks and technology methods based on CSCW all have shortages and problems. For example in situation of cooperative graphics design system:The application sharing systems, such as NetMeeting, have strong capability of graphics application and compatibility of open data format of CAD systems but with weak collaborative performance and only provide floor control mode; The prototype CSCD systems and collaborative graphics editing systems in distributed interactive environment has strong collaborative design performance but with weak capability of graphics application and compatibility of open data format. Therefore, it is necessary to integrate with CAD system, on the basis of existing software architecture of distributed interactive simulation, further improve the existing system construction methods of collaborative design, and establish a standard, open collaborative design platform.In the paper, aimed at these shortages of existing in two basic types of collaboration frameworks and technical route, and through analyzing problems of real-time collaborative design for complex products and applications of High Level Architecture (HLA) in engineering collaborative design, a system architecture based on HLA for real-time collaborative design is presented. Design federate, management federate and monitoring federate with different authorities and functions are defined respectively. In order to implement data consistency, interoperability and conflict resolution in collaborative design, based on the system architecture, the paper make thorough research in a number of key technologies for collaborative design management, and put forward some new technical ideas and methods. Through the integration of existing CAD systems, the traditional CAD system with human-computer interaction function is transformed into a collaborative graphics editing prototype system with human-human interaction function.The main content of the paper is summarized as follows:(1) Study on construction method for collaborative design system architecture based on high level architecture (HLA) and the federate organizational structure and implementation procedure.Through researching and analyzing HLA application in the military and engineering domains, the modeling method by using HLA for distributed interactive simulation is summaried. In the theoretical research, focusing on analysis of HLA specifications and features, and construction method of collaborative design system architecture for complex products by using UML object-oriented modeling approach and system description capability from the software engineering point of view based on domain mapping theory and federation development and execute process model (FEDEP) is presented. In addition, the basic federate organization structure and implementation process are studied in collaborative design system. A general ideas and methods are provided for the construction of collaborative design system.(2) Study on collaborative design system architecture based on HLA and interoperability mechanism among federates.Through analyzing the existing problems in the process of constructing collaborative system by using three distributed component technologies, according to the co-design features and taking into account factors such as interoperability, reusability, adopting HLA as a common technical framework for system design, a federate real-time collaborative design environment (CoFedCADEnv_HLA) based on HLA is constructed, and the co-design system architecture is described from logical structure and functional structure respectively.In the aspect of logical structure, the distributed co-design environment is constructed by using component technology of multi-platform and sub-field. The collaborative design system architecture for complex products consists of product design platform, collaborative control platform and validation/optimization platform. The product data model of collaborative design-oriented is proposed, and it consists of four modules:update data, structure data, management data and function data. By analyzing information relations among four data modules, and the function and composition of each platform are described.In the aspect of function structure, collaborative design system architecture is constructed by utilizing method of federate functional modularity. By combining CSCD system advantages in collaboration performance with traditional CAD system advantage in graphics processing at present, collaborative framework with highly flexible, open, easy system autonomy and management is constructed.The basic functions of federation and federate is described in collaborative design environment of federate as the core. Design federate, management federate and monitoring federate with different authorities and functions are defined in the corresponding function platform respectively, and concrete logical structure of each type of federate is constructed. The logical relationship among function modules and the specific functions of each module are introduced, and interoperability mechanisms and methods between federates are studied.(3) Based on conservative time management strategy in HLA, federate time advancing model (TimeAdvMod_Fed) which applied to collaborative design system is presented. Data inconsistency problems that may arise in the process of collaborative design due to concurrent operation, so the methods of solving the problems are analyzed. The design criterion for concurrency control is summarized in detail, and the necessity of using time management in collaborative design system is indicated. By introducing time management theory in HLA to concurrency control algorithm modeling of co-design system, time management strategies used in co-design system are proposed. The conservative time advancing mechanism is adopted in CoFedCADEnv_HLA. Through analyzing the federate function in each platform, the corresponding time management mechanism and time advancing mode are set, and the implementation process of collaborative advancing logical time by management federate and design federate. The method ensures data consistency and event serialization, at the same time effectively avoids conflict operations.(4) The role management model based on federate access control (RoleCtrlMod_Fed) and the arbitration algorithm model of floor control (FloorCtrlMod_DFed) are established, and the data consistency maintenance under the floor control is realized.Design federate has determined design permissions owned product objects, when it joins the group in co-design system, so in order to achieve cooperative work among federates, the principles and methods of transforming design permission between federates are studied in detail.Through analyzing federate characteristics in the process of collaborative design, the model of role management based on federate access control (RoleCtrlMod_Fed) is proposed, and the corresponding project permission of federate role is analyzed and summarized. The access control technology role-based which to achieve by using the definition of the five-tuple is proposed.The ownership relation between the instance properties of product object and design federate is studied, and the floor control mechanisms with "push, pull" modes based on ownership management services in HLA are proposed. The send and receive data which federate publishes and subscribes in the fixed group are completed by using data distributed management service. By analyzing and summarizing the federate role of the corresponding project permission and the modes of floor control, the arbitration algorithm model of floor control (FloorCtrlMod_DFed) is proposed, and the data consistency maintenance of floor control can be completed based on the model.(5) The control model of design dynamic registration (to join or exit) (DynRegMode_DFed) is proposed. On the basis of the DynRegMode_DFed, the initial data consistency of design dynamic registration is maintained.The real-time communication protocol and operation locking mechanism based on design federate is introduced by researching and analyzing the methods of conflict resolution. By mean of calculating and analyzing the number of event interactions when the event logic counter located in different federate, the conclusion that event logic counter is set in critical section of design federate to record the number of events in design event queue is obtained. The way solves the problem of recording events real-timely in design federate external and internal event queue.The feasibility analysis of design dynamic registration is carried out, and the implement process and method that design dynamic join or exit group is discussed. In order to maintain data consistency after design federate dynamic registration, the control model of design federate dynamic registration (DynRegMod_DFed) is developed based on TimeAdvMod_Fed and event logic counter.Finally, taking ship outfitting co-design for example, an application scheme of prototype system is provided, and the program implementation of operation event interface and running instance are described.From what has been discussed above, aiming at the actual characteristics of product design in enterprises, the paper carries out theoretical and applied research around some key issues of the basic framework of collaborative design system, collaborative intelligent design and interaction management techniques. By using the construction method of co-design system architecture based on federate, the federate real-time co-design environment based on HLA (CoFedCADEnv_HLA) is constructed, and three types of federate with different function is defined according to the characteristics of co-design system architecture. On the basis of CoFedCADEnv_HLA, some of the key technologies in interaction management are studied. In order to avoid concurrent conflict, using the TimeAdvMod_Fed to ensure operation event serialization of design federate. Based on RoleCtrlMod_Fed and FloorCtrlMod_DFed, floor control of product objects among federates in the process of collaborative design is implemented; based on DynRegMod_DFed, the plug and play of design federate is implemented in the process of collaborative design.