【作者】 李建莲；

【导师】 叶继华；

【作者基本信息】 江西师范大学 ， 计算机科学与技术， 2011， 硕士

【摘要】 随着人们探索自然领域的拓展,控制系统的规模日益扩大,复杂程度逐渐增加。对系统进行建模、仿真和分析是对系统进行进一步设计实现的基础,其研究具有非常重要的意义。智能控制系统通常具有分层结构,各模块之间的信息可能是定量信息,也可能是定性信息,有时还有可能出现模糊随机的时变信息。因此,无论在系统行为特征还是控制策略方面,都体现了其复杂性和不确定性。通常,智能控制系统是一个异步并发系统,而Petri网刚好在描述分析异步并发系统方面具有独特优势。Petri网是一种图形化的语言,具有强大的描述、分析复杂系统的能力。Petri网可以把复杂问题转化为更简单清晰的图形,能够精确描述事件的顺序、异步、并发和冲突关系,既能表达系统静态结构又能对系统进行动态行为分析。因此,Petri网非常适合用于对智能控制系统进行建模和分析。本文选用智能电梯系统作为研究对象,建立基于Petri网的仿真模型。针对智能电梯系统的需求和特点,通过在基本Petri网中引入分层、时间和颜色的概念,采用一种复合高级Petri网——分层时间有色Petri网(Hierarchical Timed Colored Petri Nets,以下简称HTCPN)来建立智能电梯群控系统的HTCPN模型。该模型解决了采用基本Petri网建模节点过多,状态空间爆炸,没有时序等问题。然后,选择CPN主流仿真工具CPN Tools作为构建HTCPN模型的工具。结合该工具中替代变迁与融合库所的概念,对智能电梯控制电路进行了分层建模和融合,完成了基于HTCPN的智能电梯控制电路仿真模型。最后通过模型的仿真运行,分析了模型的相关性能,验证了该模型的正确性和可行性。通过与非并联控制的双梯单独服务情况的对比,得出采用双梯并联控制实现了对系统的优化。更多还原

【Abstract】 As the expansion of natural areas people explored, the scale of control system is getting larger and larger, and its complexity is increasing gradually. Establishing a simulating model for system analysis is the basis for further design and implementation. This research is very significant now. Intelligent control systems usually have a hierarchical structure. The information between the modules may be quantitative information, qualitative information, or sometimes may be fuzzy random time-varying information. Therefore, both the behavioral characteristics and control strategy of the system is complex and uncertain. Usually, the intelligent control system is an asynchronous concurrent system. Petri net just has a unique advantage for describing the asynchronous concurrent systems. Petri net is a graphical language. It’s a powerful tool for describing and analyzing the complex systems. The complex issues can be transformed into more simple and clearer graphics by Petri nets. Petri nets can accurately describe the relationship between the events, such as sequence, asynchronous, concurrent, conflict, etc.. It can both express the static structure of the system and analyze the dynamic behavior of the system. Therefore, Petri nets are fairly suitable for modeling and analyzing the intelligent control systems.This paper selected intelligent elevator system as the research object, established simulation model based on Petri nets. In view of the needs and characteristics of intelligent elevator system, introduced concepts of hierarchy, time and color to the basic Petri nets. Used a composite high-level Petri nets - Hierarchical Timed Colored Petri nets (hereinafter referred to as HTCPN) to create HTCPN model of intelligent elevator group control system. The model solves the problem of too many nodes, state space explosion, no timing and other issues based on basic Petri net model. Then, selected the mainstream simulation tool CPN Tools for establishing HTCPN model. With its modeling techniques of substitution transition and fusion place, established an HTCPN model of intelligent elevator control circuit. Finally, by simulation running of the model, analyzed the relative performance of the model, verified the correctness and feasibility of the model. By contrast with the situation of non-parallel control system providing a separate service, the elevator system which adopted the parallel control strategy achieved a better performance.更多还原