Fuzzy Reasoning as a Control Problem

Different from the dominant view of treating fuzzy reasoning as generalization of classical logical inference, in this paper fuzzy reasoning is treated as a control problem. A new fuzzy reasoning method is proposed that employs an explicit feedback mechanism to improve the robustness of fuzzy reasoning. The fuzzy rule base given a priori serves as a controlled object, and the fuzzy reasoning method serves as the corresponding controller. The fuzzy rule base and the fuzzy reasoning method constitute a control system that may be open loop or closed loop, depending on the underlying reasoning goals/constraints. The fuzzy rule base, the fuzzy reasoning method, and the corresponding reasoning goals/constraints define the three distinct ingredients of fuzzy reasoning. While various existing fuzzy reasoning methods are essentially a static mapping from the universe of single fuzzy premises to the universe of single fuzzy consequences, the new fuzzy reasoning method maps sequences of fuzzy premises to sequences of fuzzy consequences and is a function of the underlying reasoning goals/constraints. The Monte Carlo simulation shows that the new fuzzy reasoning method is much more robust than the optimal fuzzy reasoning method proposed in our previous work. The explicit feedback mechanism embedded in the fuzzy reasoning method does significantly improve the robustness of fuzzy reasoning, which is concerned with the effects of perturbations associated with given fuzzy rule bases and/or fuzzy premises on fuzzy consequences. The work presented in this paper sets a new starting point for various principles of feedback control and optimization to be applied in fuzzy reasoning or logical inference and to explore new forms of reasoning including robust reasoning and adaptive reasoning. It can be also expected that the new fuzzy reasoning method presented in this paper can be used for modeling and control of complex systems and for decision-making under complex environments.     

Robustness of fuzzy reasoning and δ-equalities of fuzzy sets

Fuzzy reasoning methods (or approximate reasoning methods) are extensively used in intelligent systems and fuzzy control. In this paper the author discusses how errors in premises affect conclusions in fuzzy reasoning, that is, he discusses the robustness of fuzzy reasoning. After reviewing his previous work (1996), he presents robustness results for various implication operators and inference rules. All the robustness results are formulated in terms of δ-equalities of fuzzy sets. Two fuzzy sets are said to be δ-equal if they are equal to an extent of δ     

高精度RBP-模糊推理复合学习系统

该文提出了高精度RBP-模糊推理复合学习系统.系统主要由基于鲁棒估计的鲁棒BP 学习环节和基于混合合成推理的模糊推理环节构成.该学习系统的主要特点是可由鲁棒BP 算法和min-max,max-min模糊推理算法简单地实现.最后通过在目标跟踪问题中应用结 果,表示了该算法的高精度和鲁棒性.     

高精度RBP－模糊推理复合学习系统

该文提出了高精度ＲＢＰ－模糊推理复合学习系统．系统主要由基于鲁棒估计的鲁棒ＢＰ学习环节和基于混合合成推理的模糊推理环节构成．该学习系统的主要特点是可由鲁棒ＢＰ算法和ｍｉｎ－ｍａｘ，ｍａｘ－ｍｉｎ模糊推理算法简单地实现．最后通过在目标跟踪问题中应用结果，表示了该算法的高精度和鲁棒性．     

Fuzzy backward reasoning using fuzzy Petri nets

Chen, Ke and Chang (1990) have presented a fuzzy forward reasoning algorithm for rule-based systems using fuzzy Petri nets. In this paper, we extend the work of Chen, Ke and Chang (1990) to present a fuzzy backward reasoning algorithm for rule-based systems using fuzzy Petri nets, where the fuzzy production rules of a rule-based system are represented by fuzzy Petri nets. The system can perform fuzzy backward reasoning automatically to evaluate the degree of truth of any proposition specified by the user. The fuzzy backward reasoning capability allows the computers to perform reasoning in a more flexible manner and to think more like people.     

Genetic fuzzy learning

A hybrid approach to fuzzy supervised learning is presented. It is based on a genetic-neuro learning algorithm. The mixed-genetic coding adopted involves only the premises of the fuzzy rules. The conclusions are derived through a least-squares solution of an over-determined system using the singular value decomposition (SVD) algorithm. The paper presents the results obtained with C++ software called GEFREX that implements the proposed algorithm. The main characteristic of the algorithm is the compactness of the fuzzy systems extracted. Several comparisons ranging from approximation problems, classification problems, and time series predictions show that GEFREX reaches a smaller error than found in previous works with the same or a smaller number of rules. Further, it succeeds in identifying significant features. Although the SVD is used extensively, the learning time is decidedly reduced in comparison with previous work     

模糊描述逻辑FALNUI的tableaux推理

分析了模糊描述逻辑FALNUI与模糊ER模型的关系,即模糊ER模型可以转化为FALNUI的知识库,并且模糊ER模型的可满足性、冗余性和包含关系等推理问题可以转化为FALNUI的包含推理问题,但FALNUI缺乏相应的推理算法.提出了一种基于描述逻辑tableaux的FALNUI的可满足性推理算法,证明了该推理算法的正确性,以及提出了FALNUI的Tbox扩展和去除方法,证明了FALNUI的包含推理问题可以转化为可满足性推理问题,并给出了FALNUI的包含推理算法.FALNUI的tableaux推理算法为模糊ER模型的可满足性、冗余性和包含关系等自动推理的实现提供了理论基础.     

面向语义Web语义表示的模糊描述逻辑

分析了语义Web语义表示理论的研究现状及存在的问题,提出了一种新的面向语义Web语义表示的模糊描述逻辑FSHOIQ(fuzzy SHOIQ).给出了FSHOIQ的语法和语义,提出了FSHOIQ的模糊Tableaux的概念,给出了一种基于模糊Tableaux的FSHOIQ的ABox约束下的可满足性推理算法,证明了可满足性推理算法的正确性.提出了FSHOIQ的TBox扩展和去除方法,并证明了FSHOIQ的TBox约束下的包含推理问题可以转化为ABox约束下的可满足性推理问题.FSHOIQ为语义Web表示和推理模糊知识提供了理论基础.     

一种基于模糊PID的AFS电机控制方法

本文在基于汽车驾驶模拟器的自适应前照灯系统(Adaptive Front-Lighting System,AFS)半实物硬件仿真平台上,根据AFS动力学模型的特性,提出一种基于模糊PID控制的AFS步进电机控制方法。该方法以AFS动力学模型输出为输入,利用实验获得的经验人为创建语言控制规则,并依据其进行模糊推理,构成模糊规则表,计算模糊关系最终获得模糊输出判决。在实验中运用MATLAB工具将模糊PID算法和常规PID算法进行对比,并在AFS半实物仿真平台上进行性能分析。实验结果表明,模糊PID算法明显优于常规PID算法,且更适合AFS系统中步进电机的控制需求。     

模糊推理Petri网及其在故障诊断中的应用

分析了推理Petri网与传统Petri网的共性和区别,给出了模糊产生式规则推理 Petri网模型.在此基础上,给出了有效的推理算法,并以极大代数矩阵算子进行了形式化表 示,此算法充分利用了Petri网的数学理论基础和描述并发系统的能力,具有并行推理能力, 可以同时得到推理后系统的全部状态值.最后举例说明了其在故障诊断中的应用.     

Compensatory neurofuzzy systems with fast learning algorithms

In this paper, a new adaptive fuzzy reasoning method using compensatory fuzzy operators is proposed to make a fuzzy logic system more adaptive and more effective. Such a compensatory fuzzy logic system is proved to be a universal approximator. The compensatory neural fuzzy networks built by both control-oriented fuzzy neurons and decision-oriented fuzzy neurons cannot only adaptively adjust fuzzy membership functions but also dynamically optimize the adaptive fuzzy reasoning by using a compensatory learning algorithm. The simulation results of a cart-pole balancing system and nonlinear system modeling have shown that: 1) the compensatory neurofuzzy system can effectively learn commonly used fuzzy IF-THEN rules from either well-defined initial data or ill-defined data; 2) the convergence speed of the compensatory learning algorithm is faster than that of the conventional backpropagation algorithm; and 3) the efficiency of the compensatory learning algorithm can be improved by choosing an appropriate compensatory degree.     

Weighted fuzzy interpolative reasoning for sparse fuzzy rule-based systems

In this paper, we present a weighted fuzzy interpolative reasoning method for sparse fuzzy rule-based systems, where the antecedent variables appearing in the fuzzy rules have different weights. We also present a weights-learning algorithm to automatically learn the optimal weights of the antecedent variables of the fuzzy rules for the proposed weighted fuzzy interpolative reasoning method. We also apply the proposed weighted fuzzy interpolative reasoning method and the proposed weights-learning algorithm to handle the truck backer-upper control problem. The experimental results show that the proposed fuzzy interpolative reasoning method using the optimally learned weights by the proposed weights-learning algorithm gets better truck backer-upper control results than the ones by the traditional fuzzy inference system and the existing fuzzy interpolative reasoning methods. The proposed method provides us with a useful way for fuzzy rules interpolation in sparse fuzzy rule-based systems.     

聚焦式模糊变结构控制及其在主汽温控制中的应用

针对具有纯滞后、大惯性、参数漂移大的非线性复杂系统,本文提出一种聚焦式模糊变结构控制算法,使系统在多种干扰下具有较强鲁棒性的同时,具有较快的响应速度．控制器采用偏差e、偏差变化速率de/dt和偏差累积∫edt作为输入信号,利用聚焦式量化算法对这3个输入论域进行离散化,模糊化后采用模糊变结构算法对三维输入进行二维的模糊推理,大大简化了模糊推理的过程．仿真结果表明:新算法具有很好的动态品质,可以有效地消除系统的稳态误差．该算法在广东某电厂2#机组锅炉的汽温控制系统中得到成功的应用,其控制效果良好．     

锅炉系统的神经模糊智能控制研究

将神经网络与模糊集相结合形成一类新的智能信息处理方法,利用神经网络的并行运算能力来实现模糊规则的快速推理,并用学习算法在线调整规则。通过在锅炉系统的仿真研究,证明了该系统的良好性能。     

网页在线评论情感倾向的直觉模糊分类

网页在线评论的情感分类关系到个人决策、企业管理甚至社会安全。提出了一种基于直觉模糊推理的情感分类方法,通过样本库的学习将特征在分类时的不确定性分别用隶属度、非隶属度、犹豫度定量地描述,同时定量地考虑程度副词、转折词、否定词对表达情感的作用,然后通过对特征的直觉模糊信息的集结,按词组、句子、文本三个级别依次合其情感倾向,得到文本的情感倾向。在对公开语料库的比较实验中证明了该方法的正确性和分类性能。     

应用带标识的模糊Petri网的模糊推理

本文针对模糊推理中常存在推理结果意义不明确的问题,提出应用带标识的模糊Petri网(MFPNs)进行模糊推理。推理的过程中考虑模糊产生式规则的权值、阈值、确定性因子等几种知识表示参数以获得更多信息。给出基于相似性测度的模糊推理算法,通过计算带标识的模糊Petri网的最终输出库所中的托肯值可以得到最终的模糊推理结果。通过实例可以验证这样得到的推理结果意义更明确,计算过程更加高效。     

加权模糊推理网络及在水淹层识别中的应用

提出了一种加权模糊推理网络的结构模型和学习算法，该网络的基本信息处理单元为模糊推理神经元，融合了模糊逻辑能够较完整的表达领域规则和先验知识以及神经网络自适应环境的优点。根据模糊推理规则的量化表示形式和微分方程数值解的动力学思想推导出网络一种新的学习算法。该算法具有稳定，收敛速度快，且能较好避免网络学习陷入局部极值点。以油田生产复杂水淹层识别问题为例，验证了模型和算法的有效性。     

改进的模糊Petri网在民航飞机故障诊断中的应用

针对民航飞机系统的复杂性,采用了反正向推理相结合的模糊Petri网的故障诊断模型.首先,依据预设的变迁阈值,采用反向搜索策略,对建立好的模糊Petri网模型进行约简,以减小后续推理规模,提高推理搜索速度;然后采用正向推理算法进行数值计算,将复杂的推理过程通过矩阵运算实现,充分利用了模糊Petri网的并行处理能力,使模糊...     

一种基于改进T-S模糊推理的模糊神经网络学习算法

针对模糊神经网络学习算法计算量过大,在预测模型设计中提出了基于改进T-S模糊推理的模糊神经网络学习算法。主要工作如下:首先,改进T-S模糊推理方法,定义基于偏移率的T-s模糊推理方法;然后,通过将此模糊推理方法与基于合成规则的模糊推理方法及距离型模糊推理方法相比较可以看出,所提方法有较少的计算量,且比较有效;最后,在此基础上改善了模糊神经网络学习算法,并将其应用于天气预测与安全态势预测。测试结果表明,该方法明显改善了学习效率,减少了预测模型设计中的学习次数与时间复杂度,并降低了学习误差。