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ELIZABETH BRADLEY 《控制论与系统》2013,44(5):499-519
Control algorithms that exploit chaotic behavior can vastly improve the performance of many practical and useful systems. Phase-locked loops, for example, are normally designed using linearization. The approximations thus introduced lead to lock and capture range limits. Design techniques that are equipped to exploit the real nonlinear nature of the device loosen these limitations. The program Perfect Moment is built around a collection of such techniques. Given a differential equation and two points in the system's state space, it automatically selects and maps the region of interest, chooses a set of trajectory segments from the maps, uses them to construct a composite path between the points, and causes the system to follow that path via appropriate parameter changes at the segment junctions. Rules embodying theorems and definitions from nonlinear dynamics are used to limit complexity by focusing the mapping and search on the areas of interest. Even so, these processes are computationally intensive. However, the sensitivity of a chaotic system's state-space topology to the parameters of its equations and the sensitivity of the paths of its trajectories to the initial conditions make this approach rewarding in spite of its computational demands. Controlled trajectories found by this program exhibit a variety of interesting and useful properties. For example, detours through chaotic regions can be used to steer trajectories across boundaries of basins of attraction, effectively altering both the geometry of and convergence properties within a particular convergence region, such as the capture range of a phase-locked loop circuit. 相似文献
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本文对开放式系统的安全域进行了讨论,对安全域之间的关系进行了阐述,针对安全域模型,结合安全域的多级安全的特点,对安全域模型进行了研究。对于开放分布式系统的多级安全域的特点,提出采用自治Agent来实现的多域安全框架。 相似文献
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小口径管道对接焊缝处的内防腐处理是一大技术难题,作者研制了用于ψ75内径的这内补口作业机器人。 相似文献
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合同计算技术是一种崭新的计算资源管理策略,在该策略中,使用计算资源的实体需要获取计算资源的使用情况,但在一般系统中却没有这方面的信息,在本文里,我们介绍了如何使得计算资源可被预先估计的系统设计问题。 相似文献
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《自动化学报》1999,25(5):1
An approach for the design of
robust control for uncertain nonlinear systems is proposed.An appropriate differential
operator is conveyed to the controlled plant by a network of cascade compensation,while
its remained part is passivitized via optimum bangbang control.A proper signfollowing
system is introduced to make the feedforward pass strictly passive.The whole feedback
system is strongly robust.The cases for stable,unstable,inversely unstalbe plants are
discussed. 相似文献
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混合控制系统及其分析与设计方法 总被引:6,自引:0,他引:6
混合控制系统是指那些由实时产了系统和实时数值反馈子系统组成的系统,这类系统的特点是事件变量和时间变量的演化在不同系统内并行,实时地进行,本文基于对混合控制系统以往研究框架的分析,给出了混合控制系统的一个新框架,并提出了混合动态系统的分析和设计方法,混合控制系统的包括系统性能指标的分解,决策子系统的设计和实时数值反馈子系统的设计,其分析则分为离散时间域和离散事件域分析,文中采用了煤气炉系统作为例子说 相似文献
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机械传动系统的自动布置设计 总被引:1,自引:0,他引:1
布置设计是连接产品概念设计与结构设计的桥梁,本文以龙门铣变速箱能CAD系统的研究为背景,探讨了机械传动系统的计算机自动布置原理和方法,本文将产品布置设计划分为2个层次,提出了基于实例的定性布置和基于约束的参数布置相结合的布置设计求解框架。同时还提出了一种描述传动系统布置设计的表达模型-二维双向链表,该链表能统一描述与布置设计有关的信息,支持自顶向下的产品设计模式。 相似文献
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This article presents an innovative method for designing fuzzy systems composed of fewer fuzzy rules. The conventional approach to fuzzy-system design usually assumes that there exists no correlation among input variables, therefore, grid-type fuzzy partitions are widely adopted. However, in many cases, it is likely that input variables are highly correlated with one another. To avoid the problem of growth of partitioned grids in some complex system, we used an aggregation of hyperrectangulars with different size and different positions to approximate fuzzy partitions that are arbitrarily shaped. The corresponding parameters defining these hyperrectangulars are selected by using genetic algorithms. Furthermore, the number of fuzzy rules of the constructed system can be automatically minimized by choosing a special fitness function that takes this factor into account. Finally, an inverted pendulum control and nonlinear modeling problems are utilized to illustrate the effectiveness of the proposed method. 相似文献
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For the first time, in this paper, a stability test procedure is proposed for linear time‐invariant fractional order systems (LTI FOS). Paper extends some basic results from the area of finite time and practical stability to linear, continuous, fractional order time invariant time‐delay systems given in state space form. Sufficient conditions of this kind of stability, for particular class of fractional time‐delay systems is derived. 相似文献
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PID控制系统的鲁棒性分析与设计 总被引:4,自引:0,他引:4
本文分析了过程控制中广泛应用的 PID 控制系统的鲁棒性,得出了 PID 控制系统鲁棒稳定的必要条件并指出了 PID 调节器的局限性.本文提出了一种采用约束寻优方法选取 PID 参数的方法,该方法兼顾了性能指标和鲁棒性要求.这种设计方法直接考虑了模型不确定性函数,设计出具有明确鲁棒性范围的控制系统. 相似文献
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从线性代数的基本理论出发,研究遗传学中的常染色体遗传和常染色体隐性病遗传的规律,并采用Visual Java 对这一研究结果编程,在互联网上设计实现了对遗传特征逐代传播规律的研究. 相似文献