共查询到18条相似文献,搜索用时 78 毫秒
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针对无人机非线性、强耦合等特点,提出了基于该自结构动态递归模糊神经网络的姿态控制系统,给出了基于Lyapunov函数的系统稳定性证明。对四层模糊神经网络进行了优化和改进,设计了自结构动态递归模糊神经网络,该网络可以根据系统状态在线更新权值、创建/删除节点、优化网络结构。仿真表明:该控制方法的突出优点是,在兼顾考虑了系统中的不确定性因素、非线性因素及外部干扰并存的情况下,保证系统的稳定性和跟踪性能;同时此网络结构比固定结构的模糊神经网络响应速度快,因此更具优越性。 相似文献
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基于进化策略的动态递归神经网络建模与辨识 总被引:3,自引:1,他引:3
提出一种采用进化策略实现动态递归神经网络结构、权重和自反馈增益同时进化的学习算法,以及自适应进化机制,与改进BP6算法相结合,各取所长,形成集成化动态递归神经网络建模辨识算法,实际应用结果表明,所提出算法不仅明显提高了动态递是 网络模型辨识自救的收敛速度格精度,而且实现了动态递归网络的全自动优化设计。 相似文献
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直接自适应动态递归模糊神经网络控制及其应用 总被引:1,自引:0,他引:1
针对某些仿射非线性系统中各状态变量间呈微分关系的特点,本文提出仅取某些可测状态变量
作为动态递归模糊神经网络(dynamic recurrent fuzzy neural network, DRFNN) 的输入,而由DRFNN 的反馈矩阵
描述系统内部动态关系的直接自适应DRFNN 控制算法,克服了将系统所有变量作为输入的传统模糊神经网
络(traditioanl fuzzy neural network, TFNN) 因某些不可测状态变量所导致的不可实现问题.在电液伺服系统中的
应用结果表明:直接自适应DRFNN 控制算法相对于TFNN 控制算法对系统稳态特性的改善具有较大的优越
性. 相似文献
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针对递归模糊神经网络(Recurrent fuzzy neural network, RFNN)的递归量难以自适应的问题, 提出一种基于小波变换–模糊马尔科夫链(Wavelet transform fuzzy Markov chain, WTFMC)算法的RFNN模型.首先, 在时间维度上记录隐含层神经元的模糊隶属度, 并采用小波变换将该时间序列进行分解, 通过模糊马尔科夫链对子序列的未来时段进行预测, 之后将各预测量合并后代入递归函数中得到具有自适应性的递归量.其次, 利用梯度下降算法更新RFNN的参数来保证神经网络的精度.最后, 通过非线性系统建模中几个基准问题和实际污水处理中关键水质参数的预测实验, 证明了该神经网络模型的可行性和有效性. 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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提出一种基于动态递归神经网络的自适应PID控制方案,该控制系统由神经网络辨识器和神经网络控制器组成。辨识器采用单隐层的动态递归神经网络,网络结构为2-4-1;辨识算法为动态BP算法;控制器采用两层线性结构的神经网络,输入为系统偏差及其一阶、二阶微分,因此具有增量型PID控制结构。应用该控制系统对一非线性时变系统进行仿真研究,仿真结果表明该控制方案不仅具有良好的跟踪特性,而且对系统参数变化具有较强的鲁棒性。 相似文献
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提出了船舶电力吊舱推进系统的复合控制策略,以消除吊舱推进的过冲现象并获得快速平滑的动态响应.复合控制由鲁棒滑模控制和动态递归模糊神经网络控制组成,鲁棒滑模控制利用死区非线性和误差边界厚度法,克服系统的不确定与外界扰动,具有在线自学习算法的动态递归模糊神经网络控制促使系统的跟踪误差趋近于0.建立了基于SIMOTION的半实物仿真Siemens-Schottel推进器系统,仿真与实验结果表明,复合控制具有暂态快速和稳态平滑的动态响应,提高了吊舱推进系统的鲁棒性和运动精度. 相似文献
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R. A. Aliev B. Fazlollahi R. R. Aliev B. Guirimov 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2008,12(2):183-190
It is known that one of the most spread forecasting methods is the time series analysis. A weakness of traditional crisp time
series forecasting methods is that they process only measurement based numerical information and cannot deal with the perception-based
historical data represented by linguistic values. Application of a new class of time series, a fuzzy time series whose values
are linguistic values, can overcome the mentioned weakness of traditional forecasting methods. In this paper we propose a
fuzzy recurrent neural network (FRNN) based time series forecasting method for solving forecasting problems in which the data
can be presented as perceptions and described by fuzzy numbers. The FRNN allows effectively handle fuzzy time series to apply
human expertise throughout the forecasting procedure and demonstrates more adequate forecasting results. Recurrent links in
FRNN also allow for simplification of the overall network structure (size) and forecasting procedure. Genetic algorithm-based
procedure is used for training the FRNN. The effectiveness of the proposed fuzzy time series forecasting method is tested
on the benchmark examples. 相似文献
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This paper introduces a novel neurofuzzy system based on polynomial fuzzy neural network (PFNN) architecture. A PFNN consists
of a set of if-then rules with appropriate membership functions (MFs) whose parameters are optimized via a hybrid genetic
algorithm. A polynomial neural network is employed in the defuzzification scheme to improve output performance and to select
appropriate rules. A performance criterion for model selection is defined to overcome the overfitting problem in the modeling
procedure. For a performance assessment of the PFNN inference system, two well-known problems are employed for a comparison
with other methods. The results of these comparisons show that the PFNN inference system out-performs the other methods and
exhibits robustness characteristics.
This work was presented in part at the Fourth International Symposium on Artificial Life and Robotics, Oita, Japan, January
19–22, 1999 相似文献
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针对电力信息网络中的高级持续性威胁问题,提出一种基于混合卷积神经网络(CNN)和循环神经网络(RNN)的入侵检测模型。该模型根据网络数据流量的统计特征对当前网络状态进行分类。首先,获取日志文件中网络流量的各统计值,进行特征编码、归一化等预处理工作;然后,通过深度卷积神经网络中可变卷积核提取不同主机入侵流量之间空间相关特征;最后,将已经处理好的包含空间相关特征的数据在时间上错开排列,利用深度循环神经网络挖掘入侵流量的时间相关特征。实验结果表明,该模型相对于传统的机器学习模型在曲线下方的面积(AUC)上提升了7.5%~14.0%,同时误报率降低了83.7%~52.7%。所提模型能准确地识别网络流量的类别,大幅降低误报率。 相似文献
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基于递归神经网络的加速度传感器动态特性补偿 总被引:1,自引:0,他引:1
提出了一种基于递归神经网络的加速度传感器动态性能补偿方法,利用神经网络良好的非线性映射能力,建立传感器的动态逆模型,用实际工作参数训练神经网络,实现对加速度传感器动态特性的补偿。实验结果表明:经过动态补偿后,加速度传感器的系统工作频带得以拓宽,检测信号达到稳态的时间从补偿前的7m s缩短到大约1m s,传感器的动态性能得到明显的改善。 相似文献
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《Expert systems with applications》2014,41(6):2660-2677
Fuzzy neural network (FNN) architectures, in which fuzzy logic and artificial neural networks are integrated, have been proposed by many researchers. In addition to developing the architecture for the FNN models, evolution of the learning algorithms for the connection weights is also a very important. Researchers have proposed gradient descent methods such as the back propagation algorithm and evolution methods such as genetic algorithms (GA) for training FNN connection weights. In this paper, we integrate a new meta-heuristic algorithm, the electromagnetism-like mechanism (EM), into the FNN training process. The EM algorithm utilizes an attraction–repulsion mechanism to move the sample points towards the optimum. However, due to the characteristics of the repulsion mechanism, the EM algorithm does not settle easily into the local optimum. We use EM to develop an EM-based FNN (the EM-initialized FNN) model with fuzzy connection weights. Further, the EM-initialized FNN model is used to train fuzzy if–then rules for learning expert knowledge. The results of comparisons done of the performance of our EM-initialized FNN model to conventional FNN models and GA-initialized FNN models proposed by other researchers indicate that the performance of our EM-initialized FNN model is better than that of the other FNN models. In addition, our use of a fuzzy ranking method to eliminate redundant fuzzy connection weights in our FNN architecture results in improved performance over other FNN models. 相似文献
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针对污水处理过程中具有的非线性、大时变等特征,提出了一种基于自适应递归模糊神经网络(recurrent fuzzy neural network,RFNN)的污水处理控制方法.该方法利用自适应RFNN识别器建立污水处理过程的非线性动态模型,建立的模型可以为RFNN控制器提供污水处理过程中的状态变量信息,保证了控制器根据系统响应调整操作变量的精确性;并且RFNN辨识器及RFNN控制器基于自适应学习率进行学习,确保了递归模糊神经网络的收敛精度和速度,并通过构造李雅普诺夫函数证明了此算法的收敛性;最后,基于基准仿真模型(benchmark simulation model 1,BSM1)平台进行仿真实验.结果表明,与PID、模型预测控制及前馈神经网络相比,该方法对污水处理中溶解氧浓度和硝态氮浓度的跟踪控制精度具有明显的提升. 相似文献