共查询到16条相似文献,搜索用时 125 毫秒
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首先, 引入后件直联型分层方法及其推理规则, 以对广义混合模糊系统的输入变量实施分层, 获得分层广义混合模糊系统的输入输出表达式和推理规则数的计算公式; 然后, 基于??- 积分模(度量) 和分片线性函数证明分层后广义混合模糊系统对一类可积函数具有逼近性; 最后, 通过模拟实例给出后件直联型分层广义混合模糊系统对可积函数的逼近过程. 模拟结果表明, 所提出的方法不仅能使原系统模糊规则总数大大减少, 而且能使分层后系统仍具有逼近性.
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广义递阶Mamdani模糊系统及其泛逼近性 总被引:1,自引:1,他引:1
从解决模糊系统的“规则爆炸”问题出发,本文首先给出广义递阶M amdan i模糊系统的定义,然后证明其与具有中间变量的广义M amdan i模糊系统等价,并借助方形分片线性函数构造性的证明了在最大模和积分模意义下该系统是泛逼近器.最后仿真实例证实了该系统的有效性. 相似文献
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一种新型分层模糊系统及其逼近性能 总被引:1,自引:0,他引:1
针对分层模糊系统,提出一种新的结构形式,该分层模糊系统将各层中间变量作为后一层模糊单元输出结果中的一部分,而不再是输入项,这样不仅能够减少规则数目和辨识参数,而且避免了对不具物理含义的中间变量的模糊处理。给出新型分层模糊系统的解析表达式,证明了该分层模糊系统具有通用逼近性能,并给出存在性定理和逼近性能的充分条件。通过实例仿真表明所提出分层模糊系统具有较好的应用基础。 相似文献
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基于广义动态模糊神经网络的算法研究 总被引:1,自引:0,他引:1
在D-FNN算法基础上,提出了一种新的基于椭圆基函数的广义动态模糊神经网络方法.该方法不仅可以用于系统建模、辨识和控制,而且还可以用于模糊规则的自动生成或抽取.提出了一种模糊ε-完备性作为在线参数分配机制,避免初始化选择的随机性,同时,该算法不仅能对模糊规则而且能对输入变量的重要性作出评估,从而使每条规则的输入变量的宽度可以根据它对系统性能贡献的大小实施在线自适应调整.开发了相关的算法程序,最后针对实际案例进行了仿真分析,表明了该算法的有效性和高效性. 相似文献
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针对主动磁悬浮轴承系统具有强非线性、强耦合、模型不确定等特点,提出了一种变论域自适应模糊PID算法;该方法通过选择合适的伸缩因子,避免了传统模糊PID控制中出现规则爆炸的问题;同时针对传统伸缩因子的函数结构和参数难以确定的特点,设计了基于模糊规则的论域伸缩因子;在SIMULINK环境中对主动磁悬浮轴承系统进行仿真,仿真结果表明,变论域模糊PID算法控制的主动磁悬浮系统具有更好的动静态性能,对外界干扰具有更强的鲁棒性. 相似文献
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具有任意形状隶属函数的分层模糊系统逼近性能研究 总被引:9,自引:1,他引:9
首先证明了对任意给定的矩阵A和正数c, 一定存在向量b, 使得方程Ax=b有非负解, 且b和解的范数均小于c. 在此基础上证明了具有任意形状隶属函数的分层模糊系统对紧集上连续函数的逼近性质, 为使用分层模糊系统进行辨识或控制以避免模糊规则数目随系统变量个数呈指数增长提供了理论依据. 相似文献
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针对传统三维模糊控制器模糊规则多,在实际应用中不易实现,输入量之间相互耦合的问题,提出一种PID与模糊混合(M)型控制器.该控制策略是把三个输入量分别为偏差、偏差变化、偏差的偏差变化的一维模糊控制器加权融合实现混合(M)型控制器,解决了多变量模糊控制中的规则数量几何爆炸问题,具有更大的可控范围.针对传统模糊控制不能消除系统静差的缺陷,吸收增量式PID控制递推累加的形式,对偏差进行积分,混合(M)型控制器实现了对系统静差的消除.此外介绍了M型控制器的参数整定方法,并对其稳定性进行了分析.仿真表明,M型控制器控制效果比二维模糊控制和PID控制都好. 相似文献
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基于mass assignment 理论,提出了两类层次模糊mass assignment系统,并运用构造性证明过程证明了其全局逼近性质.由于类型1层次模糊系统的规则数与输入变量数呈线性关系,类型2层次模糊系统按逼近精度要求引入子模糊系统,因此,此两类层次模糊mass assignm ent系统可被用来有效地克服模糊规则爆炸问题,即所谓的规则数与输入变量数呈指数关系问题. 相似文献
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Xiao-Jun Zeng Keane J.A. 《IEEE transactions on systems, man, and cybernetics. Part A, Systems and humans : a publication of the IEEE Systems, Man, and Cybernetics Society》2006,36(5):1029-1039
This paper investigates the approximation capabilities of hierarchical hybrid systems, which are motivated by research in hierarchical fuzzy systems, hybrid intelligent systems, and modeling of model partly known systems. For a function (system) with known hierarchical structure (i.e., one that can be represented as a composition of some simpler and lower dimensional subsystems), it is shown that hierarchical hybrid systems have the structure approximation capability in the sense that such a hybrid approximation scheme can approximate both the overall system and all the subsystems to any desired degree of accuracy. For a function (system) with unknown hierarchical structure, Kolmogorov's theorem is used to construct the hierarchical structure of the given function (system). It is then shown that hierarchical hybrid systems are universal approximators. 相似文献
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《Information Sciences》2005,169(3-4):279-303
An efficient tool to deal with the ‘rule explosion’ problem is the hierarchical system by which a fuzzy system can be decomposed into a number of hierarchically connected low-dimensional systems. In this paper a generalized hierarchical Tagaki–Sugeno (TS) system is built. It is shown that the input–output (I/O) relationship of this generalized hierarchical system can be represented as one of a standard TS fuzzy system. And the system approximation capability is analyzed by taking piecewise linear functions as a bridge. By constructive method it is proven that the hierarchical fuzzy systems (HFS’s) can be universal approximators. For the given approximation accuracy, an estimation formula about the number of the rules needed in the HFS is established. Finally some simulation examples confirm that the HFS’s with smaller size rule base can approximate the given functions with high accuracy. The results obtained here provide us with the theoretical basis for various applications of HFS’s. 相似文献
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The generalized ordered weighted averaging (GOWA) operators are a new class of operators, which were introduced by Yager (Fuzzy Optim Decision Making 2004;3:93–107). However, it seems that there is no investigation on these aggregation operators to deal with intuitionistic fuzzy or interval‐valued intuitionistic fuzzy information. In this paper, we first develop some new generalized aggregation operators, such as generalized intuitionistic fuzzy weighted averaging operator, generalized intuitionistic fuzzy ordered weighted averaging operator, generalized intuitionistic fuzzy hybrid averaging operator, generalized interval‐valued intuitionistic fuzzy weighted averaging operator, generalized interval‐valued intuitionistic fuzzy ordered weighted averaging operator, generalized interval‐valued intuitionistic fuzzy hybrid average operator, which extend the GOWA operators to accommodate the environment in which the given arguments are both intuitionistic fuzzy sets that are characterized by a membership function and a nonmembership function, and interval‐valued intuitionistic fuzzy sets, whose fundamental characteristic is that the values of its membership function and nonmembership function are intervals rather than exact numbers, and study their properties. Then, we apply them to multiple attribute decision making with intuitionistic fuzzy or interval‐valued intuitionistic fuzzy information. © 2009 Wiley Periodicals, Inc. 相似文献
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研究了热轧带钢自动厚度控制(AGC)的鲁棒控制问题.为了消除轧制过程中其它变量对厚度控制精度的影响,提出了一种基于H∞/H2的多变量约束控制策略.首先,采用高阶未建模扰动对控制输入传函的H∞范数作为鲁棒性能指标,张力与活套等约束量对输出评价信号传函的H2范数作为LQG性能指标,建立了受约束的厚度控制模型.其次,设计了H∞/H2状态反馈鲁棒控制器,把受约束的AGC控制转化为系统在模型摄动与外界扰动下满足一定性能指标的鲁棒控制问题.最后,仿真结果表明,所设计的H∞/H2控制器具有良好的鲁棒控制特性. 相似文献