| As the expansion of the simulation field, the increase of simulation scale and the improving demand on the simulation effects, a single field of simulation has not reached the demand for complex simulation system. In actual situation, it often requires multi-disciplinary, multi-domain collaborative modeling and simulation. These domains are related to mechanical, electrical, control, networking and software, etc.. Therefore, simulation models of each area should coordinate together to complete the simulation run in the whole process of simulation. That is collaborative simulation run. HLA (High Level Architecture) is widely used as the software bus of collaborative simulation due to its better reusability and interoperability. RTI (Runtime Infrastructure) provides the underlying communication mechanism for collaborative simulation system, making data communication of each domain model efficiently.In HLA-based collaborative simulation, the complicative of simulation objects and increase of simulation nodes will cause load imbalance among simulation nodes.At the same time, because HLA itself provides only a coarse-grained data filtering and lacks the necessary congestion control mechanisms, it reduces the efficiency of the simulation inevitably. In the thesis, aiming at the load imbalance and the efficiency of data transfer, based on the previous research it proposes a variable-threshold strategy, and a load balancing method that reduces establish /disconnect the TCP/UDP connection number in the process of federate migration. Also it improves sort-based DDM dynamic matching method, and optimizes the collaborative simulation performance.This thesis firstly analyzes the simulation model and topology of collaborative simulation, and mainly researches the HLA-Based collaborative simulation model. Then it introduces the interface model, the definition, rules, object model template of the HLA structure, and based on these proposes the framework of the collaborative simulation, and designs a HLA adapter of the multi-domain model for the interaction of different domain models. It also realized the design of the simulation run manager and its functional modules.Secondly, the thesis researches load balancing methods of collaborative simulation in the HLA environment. It includes the design of HLA-based load balancing system platform, not using other third-party softwares, and on the basis of previous studies improves threshold strategy and federate migration protocol in the process of load balancing. It also proves that the load balancing method improves the time performance of collaborative simulation, which adopts a variable-threshold strategy and reduces the establish/disconnect TCP/UDP connection numberData filtering is a necessary operation of the large-scale collaborative simulation and complex products simulation. Therefore, this thesis also studies the traditional data filting algorithm such as region-based filtering algorithms, grid-based filtering algorithm and sort-based filter algorithm. It also proposes an improved sort-based DDM dynamic matching algorithm. If the update region occurs dynamic changes, this improved algorithm only match a small subset of the whole update region set, and does not re-match all regions as traditional filtering algorithms thus improving the matching efficiency of subscribe/update region. |
