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基于Volterra泛涵毋数描述,讨论了非线性系统广义频率响应函数的概念,提出并证明了这一种求解多项式为非线性系统GFRF的递推算法。该算法结构简单,计算量较小,优于以前的变换算法。 相似文献
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基于广义频率响应函数的非线性控制系统稳定性研究 总被引:6,自引:2,他引:6
基于Volterra级数的广义频率响应函数(GFRF)或称非线性传递函数,为研究非线性系统提供了新的思路,它是对线性频率分析方法的推广,其最重要的价值是实验可验证性。一些学者已经对非线性传递函数理论进行了研究,在非线性控制系统仿真、非线性系统辨识、GFRF计算方法,以及非线性传递函数理论的工业应用等方面取得了一些有意义的成果。但到现在为止,对具有无限项GFRF的非线性系统的稳定性研究还没有涉及。本 相似文献
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自适应模糊神经网络控制器设计的线性化方法 总被引:7,自引:0,他引:7
基于T-S模糊推理系统模型构造一个简化形式的Fuzzy神经网络(FNN),应用Stone-Weierstrass逼近定理证明了这种FNN网络对非线性连续函数的全局逼近性质,并利用Clarke一步加权最优预报控制性能指标及前向FNN网络辨识器模型的线性化思想,提出一种间接Fuzzy神经网络自适应控制算法,仿真结果证实了该算法的有效性。 相似文献
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函数链网络(Functional Link Network-FLN)通过对向量(或模式)的非线性扩展,将非线性照射特性引入了单层神经网络,采用δ学习规则获得了快速的学习和非线性映射特性。文中在FLN基础上,借助凸集优化思想,利用最陡梯度下降技术获得了比FLN更高的存储容量和更快速的学习速度。计算机模拟的结果证实了所提的算法性能。 相似文献
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文中就网络FQ系统的设计提出了三种相应的算法。利用多队列轮转算法实现了FQ系统的公平性;利用动态队列长度算法实现了FQ系统的可靠性;利用动态响应时间模糊算法实现了FQ系统的稳定性。 相似文献
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研究非线性奇异系统的受控不变分布问题.讨论了非线性奇异系统的受控不变分布算法与该系统经过状态反馈转化为正常非线性系统的受控不变分布算法的关系.得到了在一定条件下,正则非线性奇异系统的受控不变分布算法与该系统经过状态反馈转化为正常非线性系统的受控不变分布算法的一致性.并给出一个例子说明本文的结果. 相似文献
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双头镜像磁盘的SSTF调度算法 总被引:3,自引:0,他引:3
首先简要介绍了双头镜像磁盘系统的研究现状,然后针对双头镜像磁盘系统中传统的先来先服务(FCFS)调度算法提出一种新的调度算法:短寻道时间优先算法(Short Sueek-Time First-SSTF)。根据蒙特卡罗模拟实验方法,对双头镜像磁盘系统下的这两种调度算法进行模拟,从模拟实验的结果中定量分析出SSTF调 度算法大大提高了系统的性能。本文还讨论了在该调度算法下,系统的平均寻道时间与I/O请 相似文献
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In order to reveal the relationship between system time domain model parameters and system frequency response functions, new magnitude bounds of frequency response functions for nonlinear Volterra systems described by NARX model are established. The magnitude bound of the nth-order generalized frequency response function (GFRF) can be expressed as a simple n-degree polynomial function of the magnitude of the first order GFRF, whose coefficients are functions of the model parameters and frequency variables. Thus the system output spectrum can also be bounded by a polynomial function of the magnitude of the first order GFRF. These results demonstrate explicitly the analytical relationship between model parameters and system frequency response functions, and provide a significant insight into the magnitude based analysis and synthesis of nonlinear systems in the frequency domain. 相似文献
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二次调节流量耦联系统为非线性系统, 在Volterra 级数描述该系统的基础上, 通过SISO多项式类非线性系统的GFRF 递推算式获得二次调节流量耦联系统的广义频率响应函数GFRF(generalized frequency response function). 基于系统的GFRF, 在频域内应用非线性控制理论为系统设计了镇定控制器和非线性H∞控制器, 不仅使系统稳定, 而且能达到无超调、无稳态误差. 此外, 在白噪声条件下证明该控制器比线性控制器抗干扰性强. 相似文献
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David Rijlaarsdam Tom Oomen Pieter Nuij Johan Schoukens Maarten Steinbuch 《Automatica》2012,48(9):2381-2384
The notion of frequency response functions has been generalized to nonlinear systems in several ways. However, a relation between different approaches has not yet been established. In this paper, frequency domain representations for nonlinear systems are uniquely connected for a class of nonlinear systems. Specifically, by means of novel analytical results, the generalized frequency response function (GFRF) and the higher order sinusoidal input describing function (HOSIDF) for polynomial Wiener–Hammerstein systems are explicitly related, assuming the linear dynamics are known. Necessary and sufficient conditions for this relation to exist and results on the uniqueness and equivalence of the HOSIDF and GFRF are provided. Finally, this yields an efficient computational procedure for computing the GFRF from the HOSIDF and vice versa. 相似文献
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本文基于广义频率响应函数矩阵表示,针对一类多输入多输出非线性系统,提出了直接利用开环稳定性来判断系统闭环稳定性的新方法,并用实例仿真来验证了此判的有效性。 相似文献
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New results about the bound characteristics of both the generalized frequency response functions (GFRFs) and the output frequency response for the NARX (Non-linear AutoRegressive model with eXogenous input) model are established. It is shown that the magnitudes of the GFRFs and the system output spectrum can all be bounded by a polynomial function of the magnitude bound of the first order GFRF, and the coefficients of the polynomial are functions of the NARX model parameters. These new bound characteristics of the NARX model provide an important insight into the relationship between the model parameters and the magnitudes of the system frequency response functions, reveal the effect of the model parameters on the stability of the NARX model to a certain extent, and provide a useful technique for the magnitude based analysis of nonlinear systems in the frequency domain, for example, evaluation of the truncation error in a volterra series expression of non-linear systems and the highest order needed in the volterra series approximation. A numerical example is given to demonstrate the effectiveness of the theoretical results. 相似文献
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基于非线性频谱数据驱动的动态系统故障诊断方法 总被引:1,自引:0,他引:1
基于非线性频谱数据驱动方法, 研究了动态系统的故障诊断问题. 利用一维非线性输出频率响应函数提出一种非线性频谱特征提取方法, 为了提高实时性, 采用变步长自适应辨识算法进行求解; 根据估计偏差实时地改变步长, 兼顾了收敛速度与稳态误差; 获取了非线性频谱特征之后, 利用最小二乘支持向量机分类器进行故障识别. 通过对提升设备的故障诊断问题进行实验研究, 所得结果表明, 所提出的算法识别率高, 能满足在线诊断要求. 相似文献
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Recursive algorithms are derived to compute the generalized frequency response function matrix of multi-input multioutput (MIMO) non-linear systems as an analytical map from both non-linear differential equation models and NARX (Non-linear Auto Regressive Models with eXogenous inputs) models of the system. The algorithm is computationally compact and exposes the explicit relationship between the model parameters and the elements of the generalized frequency response function matrix and can thus provide important insights into the behaviour of non-linear systems. 相似文献