【作者】 韩守鹏；

【导师】 黄柯棣；

【作者基本信息】 国防科学技术大学 ， 控制科学与工程， 2007， 博士

【摘要】 分布式仿真技术应用领域和规模的不断扩大,对仿真系统的互操作能力和适应性提出了新的挑战。分布式仿真动态重构是在运行过程中按需对仿真进行在线调整的一种支持技术,其研究对于提高仿真系统的适应性、提升仿真在关键领域的应用层次具有重要价值,并已成为相关领域研究的前沿问题之一。论文从基本概念、体系结构、建模方法和设计实现等方面对分布式仿真动态重构的相关技术进行了系统的研究。论文从建模与仿真方法学的角度,利用动态系统层次描述规范和实体空间的概念,对仿真重构的内在本质进行了系统阐述,明确了模型语义对于仿真重构研究的重要性。为提供通用性的重构方法,论文以离散事件系统规范(Discrete EventSystem Specification,DEVS)作为系统描述的模型规范,提出了一种基于DEVS组件的可重构建模与仿真框架,该框架以具有反射能力的动态结构模型和调控机制作为仿真重构的实现技术。根据时间相关系统语义描述的基本理论,论文提出了DEVS模型的时间迹语义定义,并建立了时间转移系统(Timed Transition System,TTS)形式的DEVS语义描述方法。为提升DEVS模型的语义描述层次,进一步提出了DEVS向时间自动机(Timed Amomam,TA)模型的语义等价转换方法,从而可以利用时间自动机语义的时态逻辑校验方法对DEVS模型的语义验证问题进行研究。这些研究解决了现有非形式化的DEVS语义模型不利于进行语义性质定义和验证的问题。动态结构模型是仿真重构动作实施的依据。论文通过扩展并行DEVS模型,建立了具有分布-集中式反射能力的动态结构模型PVDSDE,该模型保持了并行DEVS模型的状态迁移结构和过程,并增加了原子及耦合模型层次的结构迁移元素和执行协议;此外,该模型满足耦合封闭性,能够支持组合式的仿真。论文对PVDSDE模型的实现机制进行了研究。对其在分布仿真支撑平台上的不同实现模式进行了对比分析,提出了扁平模式的PVDSDE/HLA仿真结构框架及调度机制;针对该实现模式下的时间管理问题,提出了一种映射式的时间推进算法,并通过实验验证了其推进效率的有效性。在仿真执行模式方面,论文对支持多剧情并发运行的分布仿真克隆技术进行了研究。将仿真克隆技术与动态结构模型相结合,实现了多剧情的并发仿真重构,从而为提高仿真执行效率及进行在线决策仿真提供了一种有效的执行手段。论文对HLA仿真克隆的体系结构和剧情区分算法进行了深入探讨,测试并分析了不同剧情区分算法对不同实现方案的适用性,并提出了基于挂接机制的仿真克隆中间件和松耦合成员体系结构的实现机制。实验结果表明,分布仿真克隆技术能够显著地提高仿真系统的运行性能。在分布仿真重构关键技术研究的基础上,论文利用模型集成计算(ModelIntegrated Computing,MIC)的方法,设计并实现了DEVS可重构仿真开发环境的原型系统。该系统支持模型驱动的仿真开发模式,并对调度器、适配器和仿真克隆工具等通用模块进行了详细设计和封装。通过该原型系统在XX对抗仿真系统的应用,验证了本文所进行的仿真重构技术研究工作的可行性。更多还原

【Abstract】 With increasing application domain and scale of distributed simulation technology, new challenges emerge in simulation interoperability and adaptability. Dynamic reconfiguration is a kind of technique which can support adapting simulation executive online. It is valuable to improve simulation flexibility and promote simulation application level in critical occasions. The research in this direction has been a frontier issue in current modeling and simulation region. In this research effort, we study this problem from four aspects: basic concept, system architecture, modeling method and realization mechanism.From the viewpoint of modeling and simulation methodology, internal nature of simulation reconfiguration is illustrated with the concepts of dynamic system level specification and entity space. In the illustration, the importance of model semantic for simulation reconfiguration research is clear. To provide general approach of simulation dynamic reconfiguration, Discrete Event System Specification (DEVS) is selected as the model specification for system description and a reconfigurable modeling and simulation framework for DEVS components is proposed. Within this framework, reflective dynamic structure model and control mechanisms constitue the critical technologies needed to be developed for simulation reconfiguration.Based on the fundamental semantic description theory of timed relative system, we propose a formal timed trajectory semantic definition for DEVS model and a method to describe it with Timed Transition System (TTS). Furthermore, to improve the semantic descriptive level of DEVS models, an equivalent semantic transformation from DEVS to Timed Automata (TA) is proposed. Then, semantic property of a DEVS model can be validated by applying temporal logic checking to its semantic equivalent TA model.Dynamic structure model is the basis for performing simulation reconfiguration activity. By extending parallel DEVS specification, we build a distributed-centralized reflective dynamic structure model called PVDSDE. This model preservs state transition structure and protocol of traditional parallel DEVS model, and also adds structure transition elements and protocols in both atomic and coupled model levels. Moreover, the model has the character of closure under coupling and can satisfy the requirements of composable simulation.The simulation realization mechanism of PVDSDE is studied in this dissertation. After comparing and analyzing several realization modes for running PVDSDE on distributed simulation platforms, we propose a flat structural framework and scheduling mechanism for executing PVDSDE models in High Level Architecture (HLA) simulation environment. For the time management issue in PVDSDE/HLA, we introduce a mapping time advancing algorithm, the effectiveness of which is validated through real experiments.As for simulation execution modes, distributed simulation cloning technique is studied, which can support performing concurrent multiple simulation scenarios in one same execution. We implement the concurrent reconfiguration of multiple scenarios simultaneously through combing simulation cloning with dynamic structural models. It improves the efficiency of simulation execution and also provides an effective running mode for implementing online-decision. The architectures and scenario partition algorithms of HLA simulation cloning are dicussed thoroughly in this research. Applicabilities of different scenario partition algorithms for different architectures are also tested and analyzed. Moreover, an articulated simulation cloning middleware and a loosely coupled federate architecture are proposed for cloning realization. Through real experiments, it is found that distributed simulation cloning technique can improve simulation executive performance evidently.Based on critical technologies studied above, we developed a prototype of reconfigurable simulation system development with the Modeling Integrated Computing (MIC) method. The prototype supports model driven development and encapsulates some general modules, such as scheduler, adapter, cloning middleware etc. In the end, the feasibility of this research effort is validated through a concrete application of the prototype in XX countermeasure simulation.更多还原