Research On Simulation Modeling Method Of Engineering Systems Based On Meta-Model And Its Application

While the research of modeling and simulation technology has been developed for decades, its application engineering system has been focused on specified engineering system. Few researches have been done on its theoretical basis and the meth of the modeling process. Because the complexity, the model of engineering system is hard to build, to maintain and to modify, thus its application is limited. An approach of modeling of engineering system which based on the mete-models and its theoretical basis is established in this thesis.An engineering system is made up by three parts which are named the logic part, the physic part and the control and decision part. They have different characteristics, relate and react to each other hierarchy. Based on the construction of engineering system, three meta-models is built to model the different part respectively. They are task meta-model, object meta-model and control meta-model. In the modeling of three meta-models, different strategies are used respectively. The meta-models affect to each other and make up the simulation framework of the engineering system.Task meta-models oriented to the task planning and design process of the system modeling. The engineer of the real system will decompose the engineering system hierarchy. Every level of the task model is oriented to its engineers of the real system. At the last level, the basic task model will obtained. The directed graph is hired to analyze the task model. The logic graph is built to describe the logic relationship of the tasks. The adjacency matrix and the rely matrix are hired to find the deadlock of the tasks. The task logic structure of the entire system is obtained by describe the logic level of the basic task models. It is the basis of the further task analyze and modeling process.Entity meta-models are the basis of the entire simulation system. They are the map of the physic part of the engineering system. Physic parts have characteristics of hybrid system.the hybrid system theory is hired to analyze and model the physic part. Two kinds of models, named object model and status object, are hired to describe the physic part. The former describes the date of the model and the relation of the date. It is the static structure of the model. The latter describes the status of the system and their relation. It is the dynamic structure of the system. The mathematic description of the model is given and the object model based on hybrid system and the status model based on hybrid automaton are built.Control meta-models are the map of the control and decision part of the engineering system. The structure of the control meta-model and its mathematic description are built. The modeling process of control model is also given. First, the real engineering step is described to collaboration graphs. Then the collaboration graphs are transmitted to sequence graphs. Last, the control model is introduced and the sequence graphs of real engineering system are transmitted to the sequence graphs of the simulation system. The control models are modularized according to the engineering steps and tasks to reduce the complexity and the workload of modeling. Control models link the task models and the entity models and the system model will obtained by the linkage.The modeling and simulation approach is verified by the virtual construction of a large scale laser system which is modeling by the approach. The structure design is contrasted at the structure design stage and the construction plan is optimized at the construction stage through the simulation. At every stage, the simulation guide and optimize the real design and construction of the laser system. The time and cost of the engineering system are reduced and the modeling approach proved to be effective.