The Research On The Application Of Model Driven Architecture In HLA-based Simulation System

The paper focus on the issues of the implementation of Model Driven Architecture (MDA) in the design and development of HLA-based distributed simulation system. The High Level Architecture (HLA) proposed by DMSO (Defense Modeling and Simulation Office) provides a solid conceptual foundation for distributed simulation and architecture for reuse and interoperation in distributed simulation.The goal of HLA is to promote interoperability and reuse between federates. The HLA is based on the premise that no simulation can satisfy all uses and users. An individual simulation or set of simulations developed for on purpose can be applied to another application under the HLA concept of the federation.HLA has wide applicability, across a full range of simulation application areas, including military, education, engineering and even entertainment, at a variety of levels of resolution. However, in many respects, HLA falls short of its promise potential. These problems can be attributed in part to the HLA standard itself, which does not address all of the architectural and design issues associated with distributed simulation environments .One example is the interoperability issuses between vendor RTIs. In addition, while HLA defines and specifies a number of key simulation services in simulation system, the HLA developer community has not yet benefited from emerging standards or mature applicably concepts (such as J2EE, Meta-Modeling).This affects not only the HLA standard itself ,but the promotion and wider-range application of HLA standard. As an advanced and successful architecture in simulation, it should has more wider-range application and more promising potentials Model Driven Architecture (MDA) introduced by Object Mangement Group (OMG) is a potential solution to these problems. MDA is addressed as an approach t to system-specification and interoperability based on the use of formal models. The core of the MDA concepts comprises the UML, XMI as well as the related XML Metadata Interchange (XMI) specification, SOAP and other OMG standards. The concepts are designed to embrace OMG middleware solutions, i.e., CORBA as well as alternatives like Microsofts's DCOM, Sun's EJB. This thesis introduces the MDA concept and shows, how the HLA can be integrated to become a standard stub for simulation application of legacy, system under development, and systems of the future. The thesis introduces the history of OMG, the MDA's initial and supported global organization. It also presents the background, the basic concept, the general framework, the related terminology and the key standards behind MDA. Meta-modeling and model transformation are explained as the key techniques of MDA. Because the MDA is based on the OMG's existed standards, such as XMI, UML, etc., it is helpful to promotion and advancement of HLA standard, which is generally regarded as the military application framework. The thesis gives detailed analysis of the reason to apply MDA's concept and methodology into HLA-based simulation applications. In one respect, it is not only the requirements of HLA standard itself , but also the promising solution of HLA standard's wider-range application. It is well-known that MDA is a general architecture for software development, however HLA is an architecture guideline for simulation application. So it is necessary to broaden the HLA's concepts to fit this integration and benefit from the advantage of MDA. In order to explain how to apply the MDA's concept into HLA-base simulation system, the thesis addresses the Federate Component Model, which is the HLA-based Component Model and combines the concept of MDA into the HLA framework. In this part, the simulation specific UML Profile and the Unified tools set are also introduced as the requirements of MDA-based simulation solution. As an implementation example, the TankSim HLA-based simulation system is presented as the example of MDA-based simulation solution. In this part, a general MDA-based simulation solution development process is introduced and implemented in the TankSim system's development. From the design of framework of TankSim system, the analysis of model, the design of modle to the simulation logic code, the thesis manifests the benefits of the MDA to HLA-based simulation.