共查询到20条相似文献，搜索用时 15 毫秒
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Yali Dong Laijun Chen Shengwei Mei 《International Journal of Adaptive Control and Signal Processing》2019,33(3):527-544
This paper is concerned with the problem of state estimation for a class of neural networks with discrete and distributed interval time‐varying delays. We propose a new approach of nonlinear estimator design for the class of neutral‐type neural networks. By constructing a newly augmented Lyapunov‐Krasovskii functional, we establish sufficient conditions to guarantee the estimation error dynamics to be globally exponentially stable. The obtained results are formulated in terms of linear matrix inequalities (LMIs), which can be easily verified by the MATLAB LMI control toolbox. Then, the desired estimators gain matrix is characterized in terms of the solution to these LMIs. Three numerical examples are given to show the effectiveness of the proposed design method. 相似文献
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Karlheinz Ochs 《International Journal of Circuit Theory and Applications》2013,41(9):960-971
The main aspect of this paper is to show that the stability of linear time‐variant systems cannot be estimated from the location of the eigenvalues. For this purpose, two simple time‐variant electrical circuits are presented, which have constant eigenvalues. As will be shown, the time‐variant circuits can be asymptotically stable although there is a positive eigenvalue and this circuit can be unstable despite negative eigenvalues only. The idea behind is a suited time‐variant state transformation of a linear time‐invariant system. An electrical interpretation of both systems and of state transformations allows for an energetic evaluation from an electrical point of view even though the analytical solution is not necessarily known. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Maurizio Ciampa Mario Poletti 《International Journal of Circuit Theory and Applications》1999,27(5):497-516
This paper is concerned with linear networks depending polynomially on parameters, when considering large values of the parameters, and their corresponding ideal networks—i.e. the networks in which all parameters are set equal to infinity. It has been taken into account that only the specification of nominal values and tolerances—and not of actual values—is physically meaningful. The stability of the ideal networks and the least hypotheses that allow us to use a previous algorithm to find monomial functions—in a single suitable variable—that describe arbitrarily large nominal values which ensure stability within a suitable constant tolerance are assumed. An integer h such that while these nominal values go to infinity then for any smooth causal excitations bounded together with their first h derivatives—in particular, for any smooth eventually periodic causal excitations—the zero‐state response of the actual networks converges uniformly on the whole time axis to that of the ideal networks is proved to exist. The proof may be used as an algorithm. An example which proves that the found class of excitations may be not the widest is given. The application of the results to the evaluation of the synchronization error due to high but finite values of the parameters in an ideally synchronizing linear network is shown. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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This paper addresses the problem of interval observer design for linear functions of state vectors of linear fractional‐order systems, which are subjected to time delays in the measured output as well as the control input. By using the information of both the delayed output and input, we design two linear functional state observers to compute two estimates, an upper one and a lower one, which bound the unmeasured linear functions of state vectors. As a particular case with output delay only, we design a linear functional state observer to estimate (asymptotically) the unmeasured linear functions of state vectors. Existence conditions of such observers are provided, and some of them are translated into a linear programming problem, in which the observers' matrices can be effectively computed. Constructive design algorithms are introduced. Numerical examples are provided to illustrate the design procedure, practicality, and effectiveness of the proposed design method. 相似文献
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针对传统的状态空间平均法在建模中损失纹波信息的缺陷,基于线性时间周期理论和谐波线性化理论,采用傅里叶分解法,建立DC/DC变换器稳态运行下的谐波状态空间模型,绘制DC/DC变换器的谐波等效电路,从频域角度描述拓扑电流和电压的映射过程;在输入侧加入小扰动,建立DC/DC变换器的谐波状态空间小扰动描述矩阵,对稳态谐波和扰动间谐波进行分析。仿真与实验结果表明,基于谐波状态空间的DC/DC电路建模方法具有极高的精确性,在未来多变流器的配网场景谐波分析中具有一定的工程运用价值。 相似文献
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Xiaofan Li Jian‐an Fang Huiyuan Li 《International Journal of Adaptive Control and Signal Processing》2018,32(9):1359-1376
This paper solves the finite‐time synchronization and adaptive synchronization problems of drive‐response memristive recurrent neural networks with delays under two control methods. First, the state‐feedback control rule containing delays and the adaptive control rule are designed for realizing synchronization of drive‐response memristive recurrent neural networks in finite time. Then, on the basis of the Lyapunov stability theory, many algebraic sufficient conditions are obtained to guarantee finite‐time synchronization and adaptive synchronization of drive‐response memristive recurrent neural networks via two control methods, which are easily verified. In addition, the estimation of the upper bounds of the settling time of finite‐time synchronization is obtained. Lastly, to illustrate the effectiveness of the obtained theoretical results, two examples are given. 相似文献
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"线性系统的几何理论"是将线性系统的动态分析转化为状态空间中相应的几何问题。这种几何方法的特点是简洁明了,避免了状态空间中大量繁杂的矩阵推演计算。工科大学生对此会感到概念抽象,难于掌握,因而需要相应的数学基础。通过从核空间、象空间、不变子空间入手,给予它以概念的解释。在此基础上,论述了线性系统能控性和能观性的几何判据。目前,几何理论已广泛应用于系统分析与综合中。 相似文献
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F. Previdi Sergio M. Savaresi P. Guazzoni L. Zetta 《International Journal of Adaptive Control and Signal Processing》2007,21(5):375-390
The problem considered in this work is the classification of the particles produced by the collision of a heavy ion beam on a target. Each particle is captured by a detector and results in a signal (which is the impulse response of a dynamic linear system), which is measured by a digital acquisition system. The assumption made herein is that the shape of the impulse‐response contains complete information on the particle, and the classification can be done by pulse‐shape, analysis. In this work, a complete procedure for the particle identification is proposed. The main idea is to use the cascade of a state‐space identification algorithm and a parametric non‐linear map using the model parameters as input regressors. The algorithm has been tested on a large set of impulse‐responses and provides a fully automatic accurate classification of the isotopes. This work focuses on isotopic identification of the most energetic light charged particles (LCP). All the experiments are made with the large detector array CHIMERA (Charge Heavy Ions Mass and Energy Resolving Array). Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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Mourad S. Semary Ahmed G. Radwan Hany N. Hassan 《International Journal of Circuit Theory and Applications》2016,44(12):2114-2133
This paper investigates some basic concepts of fractional‐order linear time invariant systems related to their physical and non‐physical transfer functions, poles, stability, time domain, frequency domain, and their relationships for different fractional‐order differential equations. The analytical formula that calculates the number of poles in physical and non‐physical s‐plane for different orders is achieved and verified using many practical examples. The stability contour versus the number of poles in the physical s‐plane for different fractional‐order systems is discussed in addition to the effect of the non‐physical poles on the steady state responses. Moreover, time domain responses based on Mittag‐Leffler functions for both physical and non‐physical transfer functions are discussed for different cases, which confirm the stability analysis. Many fractional‐order linear time invariant systems based on fractional‐order differential equations have been discussed numerically in both time and frequency domains to validate the previous fundamentals. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Lorenzo Repetto Marco Storace Mauro Parodi 《International Journal of Circuit Theory and Applications》2003,31(3):299-313
In this paper, we face the problem of model reduction in piecewise‐linear (PWL) approximations of non‐linear functions. The reduction procedure presented here is based on the PWL approximation method proposed in a companion paper and resorts to a strategy that exploits the orthonormality of basis functions in terms of a proper inner product. Such a procedure can be favourably applied to the synthesis of the resistive parts of cellular non‐linear networks (CNNs) to reduce the complexity of the resulting circuits. As an example, the method is applied to a case study concerning a CNN for image processing. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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时域有限元法求解传输线瞬态波过程 总被引：3，自引：1，他引：2
讨论了求解多导体传输线(multi-conductor transmission line,MTL)的时域有限元法(time domain finite element method,TDFE),并给出了计算动态集中元件的时域处理方法。通过与传统的数值计算方法时域有限差分法(finite difference time domain,FDTD)和国际上通用的电磁暂态计算程序EMTP的计算结果进行比较,验证了TDFE法的正确性。该方法克服了FDTD不能直接计算带有集中参数网络的传输线这一不足,而且在相同条件下,可以有效地抑制由于在FDTD方法中使用中心差分所造成的吉布斯效应。相对于EMTP只能求解所设定传输线两端的响应这一缺憾,该方法的优势在于能够得到沿线所有离散点的电压电流分布。最后,将TDFE应用于500 kV变电站开关操作时,由于电容式电压互感器的影响而在二次电缆上产生的电磁干扰的数值预测。 相似文献
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Irwin W. Sandberg 《International Journal of Circuit Theory and Applications》2004,32(3):105-116
An Erratum has been published for this article in International Journal of Circuit Theory and Applications 2004; 32(6):633. It is shown that the elements of a large class of time‐invariant non‐linear input–output maps can be uniformly approximated arbitrarily well, over infinite time intervals, using a certain structure that can be implemented in many ways using, for example, radial basis functions, polynomial functions, piecewise linear functions, sigmoids, or combinations of these functions. For the special case in which these functions are taken to be certain polynomial functions, the input–output map of our structure is a generalized finite Volterra series. Results are given for the case in which inputs and outputs are defined on ?. The case in which inputs and outputs are defined on the half‐line ?+ is also addressed, and in both cases inputs need not be functions that are continuous. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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Irwin W. Sandberg 《International Journal of Circuit Theory and Applications》2005,33(4):253-262
An expression is given for the most general input–output map associated with the members of a certain important large family of causal linear shift‐invariant systems with bounded inputs. This expression is a function‐space limit of a convolution. Also given is a necessary and sufficient condition under which the limit can be written as a convolution with an integrable impulse‐response function. Related material concerning engineering education, as well as additional results for other sets of inputs, is also given. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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One‐bit signal processing based on delta‐sigma modulation has been studied for hardware implementation of signal processing systems. In the 1‐bit signal processing, finite word‐length problems such as overflow and coefficient quantization error occur. To solve the problems, a new design method with state space is proposed in this paper. Digital filters are designed to show the feasibility of the method. First, the L1/L2‐sensitivity is shown to evaluate coefficient quantization error and L2 scaling constraints to prevent overflow. Second, a state space equation is presented and the L1/L2‐sensitivity and L2‐scaling constraints are extended to take the filter structure and oversampling effects into account. Finally, the proposed method is shown to attain a higher SNR than conventional ones. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 175(4): 48–56, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21075 相似文献
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Kai‐Sheng Lu 《International Journal of Circuit Theory and Applications》2008,36(2):109-118
If the physical parameter of each branch of a linear active network is considered to be an independently variable parameter, then it is called a network over the field F(z) of all rational functions in its physical parameters. This paper discusses the existence condition of state equation over F(z) for the active network. The condition depends only on the network structure, and is applied to two examples, which shows that the method is straightforward. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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Magnus Nilsson Bo Egardt 《International Journal of Adaptive Control and Signal Processing》2008,22(9):875-901
Feedback error learning (FEL) is a proposed technique for reference‐feedforward adaptive control. FEL in a linear and time‐invariant (LTI) framework has been studied recently; the studies can be seen as proposed solutions to a ‘feedforward MRAC’ problem. This paper reanalyzes two suggested schemes with new interpretations and conclusions. It motivates the suggestion of an alternative scheme for reference‐feedforward adaptive control, based on a certainty‐equivalence approach. The suggested scheme differs from the analyzed ones by a slight change in both the estimator and the control law. Boundedness and error convergence are then guaranteed when the estimator uses normalization combined with parameter projection onto a convex set where stability of the estimated closed‐loop system holds. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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一种小波分解回声状态网络时间序列预测方法 总被引：2，自引：0，他引：2
针对多尺度时间序列各尺度发展趋势及整体预测问题,建立小波分解回声状态网络预测模型（wavelet decomposi-tion and echo state networks,WDESN）,根据各尺度的不同性质选取与之相匹配的回声状态网络模型（echo state networks,ESN）,同时,通过在各尺度条件下引入权值系数实现预测分量最优整合,提高整体预测精度。预测带噪多尺度正弦序列实验表明：WDESN模型与ESN、支持向量机及BP神经网络模型相比预测精度较高。目前,该模型已成功用于移动通信话务量的预测,并满足了现实系统的精度要求。 相似文献