共查询到19条相似文献,搜索用时 93 毫秒
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二阶跟踪—微分器的频率特性 总被引:12,自引:0,他引:12
本文给出二阶跟踪—微分器的频率特性 ,此频率特性类似于二阶线性低通滤波器的频率特性 ,但具有线性系统所没有的优点 ,即通带内有较小的相移 ,且无谐振现象 .同时 ,文中指出频率特性与跟踪参数和正弦输入信号幅值之间的关系就是一个简单的“平移” 相似文献
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一类不确定非线性系统的适应输出反馈控制 总被引:6,自引:0,他引:6
针对一类存在有界干扰的线性参数化非线性系统,给出了一种新的适应输出反馈控制器.该控制器能保证闭环控制系统所有信号的全局有界性.该文将现有的非线性适应输出反馈控制方面的结果,从无扰动情形推广到了存在有界干扰的情形.仿真结果用来说明所设计控制器的有效性. 相似文献
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不确定非线性系统的周期信号自适应跟踪 总被引:2,自引:0,他引:2
考虑不确定非线性系统的周期信号的自适应跟踪问题. 系统的不确定性不能参数化,周期信号由一非线性系统产生.提出了跟踪周期信号的自适应控制律. 此控制律保证了闭环系统所有的信号有界和跟踪误差趋于零. 已有的有关的周期信号跟踪控制律只能保证跟踪误差的平方在一周期上的积分趋于零. 相似文献
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Modal controllers are proposed for multiple signal differentiation. Differentiator design reduces to the construction of a
servo system with modal plant controller consisting of serially connected integrating elements. The differentiation error
for the class of signals considered in this article can be made arbitrarily small by increasing the order of the differentiator
transfer function. The proposed differentiators are tolerant to high-frequency noise.
Translated from Nelineinaya Dinamika i Upravlenie, pp. 37–47, 1999. 相似文献
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《Journal of Computational and Applied Mathematics》1999,107(2):179-193
Numerical differentiation formulas based on interpolating polynomials, operators and lozenge diagrams can be simplified to one of the finite difference approximations based on Taylor series. In this paper, we have presented closed-form expressions of these approximations of arbitrary order for first and higher derivatives. A comparison of the three types of approximations is given with an ideal digital differentiator by comparing their frequency responses. The comparison reveals that the central difference approximations can be used as digital differentiators, because they do not introduce any phase distortion and their amplitude response is closer to that of an ideal differentiator. It is also observed that central difference approximations are in fact the same as maximally flat digital differentiators. In the appendix, a computer program, written in MATHEMATICA is presented, which can give the approximation of any order to the derivative of a function at a certain mesh point. 相似文献
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In this work, two special high-gain tracking differentiators are proposed. By using an ingenious technique which is based on the Taylor expansion, the time lagging phenomenon of the traditional high-gain differentiator is reduced effectively. Therefore, the differentiation exactness of the proposed differentiator is much higher than that of the traditional high-gain tracking differentiator. 相似文献
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A. V. Dylevskii 《Computational Mathematics and Modeling》2001,12(4):353-358
The state-space method is applied for noise-tolerant multiple differentiation of signals from a certain class. The construction of differentiators is reduced to the design of a state observer for a dynamical system with an unknown bounded input. Any prespecified differentiation accuracy of signals from the given class can be achieved by increasing the observer dimension, i.e., the order of the differentiator transfer function. The proposed differentiators are tolerant to high-frequency additive noise. 相似文献
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利用微分算子级数法 ,将若干类广义积分及变上限函数的积分问题化为微分运算 ,介绍它们转换的条件、公式及实例 . 相似文献
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Rajesh Pereira 《Journal of Mathematical Analysis and Applications》2003,285(1):336-348
In 1959, Davis introduced the concept of a differentiator of an operator on a finite-dimensional Hilbert space. We prove that every such operator possesses a differentiator. We also use the theory of differentiators to solve several problems in the geometry of polynomials. For instance, we answer in the affirmative a twenty year old unsolved conjecture of Schoenberg, a related conjecture of Katsoprinakis and a fifty year old unsolved conjecture of De Bruijn and Springer. 相似文献
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This paper newly designs the recursive least-squares (RLS) fixed-lag smoother and filter using the covariance information in linear continuous-time stochastic systems. It is assumed that the signal is observed with additive white observation noise and the signal is uncorrelated with the observation noise. The estimators require the covariance information of the signal and the variance of the observation noise. The auto-covariance function of the signal is expressed in the semi-degenerate kernel form. 相似文献
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相关技术在滚动轴承故障诊断中的应用 总被引:2,自引:0,他引:2
众所周知自相关技术能够有效地从随机嘈声中提取周期性信号.在滚动轴承元件的故障诊断中,由于信号图象不同,我们无法从原信号直接得到故障的情况,这种信号的显示就像宽频带随机嘈声在自相关函数的显示一样.本文中,信号经过了预处理,其结果证明是行之有效的.应用自相关技术我们还可以得到已测定的可比采样,这对于建立轴承运行条件的数据基础和进行故障诊断是十分重要的. 相似文献