【作者】 张龙斌；

【导师】 贺国光；

【作者基本信息】 天津大学 ， 系统工程， 2006， 硕士

【摘要】 在某些实时控制系统中,必须尽快地识别出混沌,以便及时采取控制措施避免系统进入无序状态。然而现有的混沌识别方法由于要求样本量大,无法满足实时性的要求。因此,研究在线实时快速判定混沌的方法不仅可以在混沌理论上填补在线实时快速判定混沌方法的空白,具有重要的学术意义,而且具有很高的实用价值。针对以上问题本文提出了一种在线实时快速判定混沌的智能方法,通过找出产生混沌的初始条件和混沌之间的对应关系,可以在混沌产生之初检测到混沌。本文首先通过相关文献的总结提炼,较为全面地总结了国内外关于混沌识别以及相关技术领域的研究现状和不足。本文提出了一种解决混沌在线实时快速识别的新思路,给出了使用智能方法解决该问题的一个总体系统框架。对各个子系统的具体实现方法分别进行了研究。包括较全面地总结了在实现智能系统中的离线识别子系统中要用到的Lyapunov指数数值计算方法,分析了各种类型数值计算方法的原理、适用特点、计算效果等;介绍了谱分析,小波分析等信号处理方法,并用这些方法对混沌信号和一般信号进行了比较分析试验,找出了适合提取时间序列混沌特征模式的信号处理方法。给出了智能方法仿真实验的实现流程并设计了仿真实验验证了智能识别方法的有效性。并将智能方法应用于交通流仿真系统的混沌识别中,在Matlab环境下研究了智能系统的具体实现,仿真实验结果表明本文提出的智能方法可以很好地满足混沌检测实时性的要求。本文对使用智能方法解决在线实时快速识别混沌这种新思路作了有益的尝试。更多还原

【Abstract】 In some real-time control systems, real-time identifying of chaos is required as early as possible, so that the control step can be adopted timely and the disorder state of system will be avoided. But the existing identifying method cannot meet this requirement because it needs a large number of samples. Therefore, the research of real-time identifying of chaos not only fills the empty of chaos theory and has important academic significance, but also has important practical value.Aiming at this question, this paper presents an intelligent method for real-time identifying of chaos; the main idea is identifying chaos at the initial time when chaos generates based on extracting the relationship between initial condition and chaos. At first, this article comprehensively summarizes the researching situation and insufficiencies of chaos identifying in the domestic and foreign domain. Then, a new thought for solving the real-time identifying of chaos is put forward and a systematic frame of the intelligent method is devised. And then this paper studies the concrete realizing methods of each subsystem respectively. Classifies and compares the characteristics of Lyapunov exponent numerical calculating algorithm, and researches the methods of extracting characteristic pattern of chaotic time series. Afterwards, a group of contrastive experiments to simulate traffic flow system were realized on MATLAB by using this intelligent method, and the validity is proved. The experiment result shows that this method can properly meet the real-time requirement of identifying chaos efficiently.The research is a significant attempt to settle real-time identifying of chaos with intelligent method .更多还原