Study On Modeling And Simulation Method For Virtual Device

With the development of long-distance education, the research of virtual experiment techniques obtains more and more high opinions. The difficulty of constructing virtual experiment systems lies in establishing virtual devices with expandable, reusable and competent quality. Present, the virtual device model building method has a lot of limitations. Virtual device models with expandable, reusable and competent qualities may be established by combining with object-oriented simulation method, component technology and Agent theory.System theory and Discrete Event System Specification (DEVS) formalism are the foundation and methodology for analysis and modeling of the virtual experiment system and virtual device.Simulation models are constituted on the basis of the objects of the system and their mutual action relationship according to the object-oriented simulation theory. The model objects express the entities in the actual system. This way is consistent with people's natural thinking means. As a result, the comprehensible quality of simulation models is heightened. Object-oriented virtual device models have the strong points such as encapsulation, expandability and reusability. The modeling granularity of component-based method is greater and more reusable. Models based on component separate the models from the simulation engine and are able to more accurately express the simulation objects' action. Virtual device models based on Agent not only have encapsulation quality and are reusable; but also have features such as autonomous and intelligent quality. The models based on Agent can simulate physics device more actually. Because Agent is an entity that can operate independently, it is easy to construct distributing virtual experiment systems with these models. These models are more natural to real experiment environment.In the "Digital Logic and Principles of Computer" virtual experiment system, virtual device library models and the simulation engine are implemented with Object-oriented programming language. As a result, the fact is illustrated that it is feasible to construct reusable and expandable models, and then establish the whole virtual experiment system with techniques mentioned above.