共查询到20条相似文献，搜索用时 140 毫秒
1.
研究线性时滞系统的时滞相关稳定性问题。利用李雅普诺夫稳定性理论结合微分不等式 ,提出了若干个时滞相关稳定性的新判据 ,并给出了系统的时滞项上界的估计公式。得到的稳定性判据较简洁 ,且具有较低的保守性。 相似文献
2.
针对一类含有输入时滞和输出时滞的离散时间系统,给出了一种无时滞转换方法,并给出了此类系统在受扰情况下的最优跟踪控制律。为避免求解含有超前项和时滞项的两点边值问题,对原时滞系统进行了无时滞转换。根据系统的最优控制理论,构造了转换后系统的二次性能指标。通过求解Riccati差分方程得到了最优跟踪控制律。构造了扰动外系统观测器和参考输入外系统观测器来解决最优跟踪控制律中所含有的前馈项的物理不可实现问题。仿真实例表明所提出的最优跟踪控制律有效。 相似文献
3.
《中国海洋大学学报(自然科学版)》2016,(10)
研究一类具有S-分布时滞的随机Hopfield神经网络的稳定性问题。通过构造随机Lyapunov泛函与随机分析技巧相结合的方法得到了实用有效的判别准则.具有S-分布时滞的Hopfield神经网络解决了具有离散时滞的Hopfield神经网络和具有连续分布时滞的Hopfield神经网络不能相互包含的问题。且本文在已有文献的系统模型中加入了随机干扰项,证明了该随机Hopfield神经网络全局解的存在唯一性及其全局均方鲁棒指数稳定性,使其具有更广泛的实际应用价值,推广了相关文献中的结果。 相似文献
4.
《中国海洋大学学报(自然科学版)》2015,(9)
本文研究了一类线性离散时滞系统的指数稳定问题。通过构造适当的Lyapunov-Krasovskii泛函,利用矩阵不等式技术,给出了线性离散时滞系统与时滞相关的指数稳定的充分条件。应用本文的结果,得到了不确定离散时滞系统与时滞相关的鲁棒指数稳定的新判据,并用数值算例说明了本文结果的可行性与有效性。 相似文献
5.
本文研究了一类线性常时滞时变系统的有限时间有界与输入-输出有限时间稳定性问题,通过构造Lyapunov泛函,并利用时变的矩阵不等式,分别获得了线性常时滞时变系统的有限时间有界和输入-输出有限时间稳定的充分条件。同时,设计了状态反馈控制器,使得闭环系统有限时间有界且输入-输出有限时间稳定,并通过仿真算例验证了本文方法的有效性。 相似文献
6.
《中国海洋大学学报(自然科学版)》2016,(3)
应用Lyapunov函数分解法(即标量和的Lyapunov函数法),结合微分方程与微分差分方程的等价性的方法(即分解等价法),研究了具有大时滞的非线性定常大系统的无条件稳定性,得到了该系统为无条件稳定的充分性判据。本文对时滞项的研究不同于以往的小时滞,找到了使含大时滞项的系统为无条件稳定的途径,从而为这类问题的研究给出了一种新方法。 相似文献
7.
研究了时滞广义时变系统的渐近稳定和镇定问题。首先利用相关不等式,通过建立Lyapunov方程,给出了1个时滞广义时变系统无脉冲、渐近稳定性的充分条件。然后,基于这一工作,利用Riccati方程,进一步研究了时滞广义时变系统的镇定问题。最后,举例说明该结论的可行性。 相似文献
8.
9.
研究一类同时存在系统时变时滞和网络随机时滞的网络控制系统的稳定性问题。首先采用切换方法描述离散线性系统的时变时滞,而利用马尔可夫链描述网络随机时滞;其次,基于线性矩阵不等式形式和V-K迭代算法给出该系统的稳定性判据和控制器设计算法;最后通过仿真实例验证了该方法的有效性和可行性。 相似文献
10.
研究在持续外界扰动作用下,具有控制时滞线性系统的动态输出反馈扰动抑制问题。首先利用模型转换将控制时滞系统转化为形式上无时滞的系统,通过求解Riccati方程和Sylvester方程,推导出前馈—反馈最优扰动抑制控制律。然后构造能同时预估状态和扰动的降维观测器,不仅解决前馈控制和状态反馈的物理不可实现问题,而且得到了近似于最优扰动抑制控制律的动态输出反馈扰动抑制控制器。仿真实例证明此控制律的有效性。 相似文献
11.
该文研究子系统间具有强耦合的线性离散大系统的稳定性。提出一种适合于该类大系统稳定性分析的部分分解法。该方法可将高阶线性离散大系统化为若干个具有单向解耦的低阶子系统来研究。从而 ,利用标量李雅普诺夫函数将高阶矩阵李雅普诺夫方程化为若干个单向解耦的低阶矩阵方程。通过线性矩阵不等式得到线性离散大系统稳定性的充分条件。 相似文献
12.
作者讨论矩阵方程 ATX+ XTA=B。该方程在 Hamilton力学研究中有用。首先利用L yapunov方程证明了极小 Frobenius范数解的存在性和惟一性。然后用奇异值分解给出了求解最小范数解的一种方法。最后讨论极小范数解的向前扰动分析和最佳向后扰动分析 相似文献
13.
Chaotic transport and mixing of a passive admixture by vortex flows behind obstacles 总被引：1，自引：0，他引：1
A two-layer nonviscous model of chaotic advection in a unidirectional pulsating running current above a delta-shaped underwater
elevation is considered. The property of local stability is used and a characteristic similar to the cumulative Lyapunov exponent
is introduced that makes it possible to determine the range of regular and chaotic particle behavior. The estimates obtained
using this characteristic are for clarifying passive admixture transport in analog model problems. Knowledge of the maximum
chaotization region boundary is important for oceanology in view of interpreting point vortices as a model of distributed
vortices. The criterion based on using the cubic Hamiltonian approximation for a nonlinear resonance model is introduced to
estimate the limiting boundary of the regular region. 相似文献
14.
讨论了一类离散非线性系统降维观测器的存在性。对给定的Lyapunov函数,在保证观测误差渐近稳定的条件下,给出了该离散非线性系统降维观测器的设计方法。用数值例子说明了该设计方法的有效性。 相似文献
15.
In this paper, a novel model reference adaptive controller with anti-windup compensator (MRAC_AW) is proposed for an autonomous underwater vehicle (AUV). Input saturations and parametric uncertainties are among the practical problems in the control of autonomous vehicles. Hence, utilizing a proper adaptive controller with the ability to handle actuator saturations is of a particular value. The proposed technique of this paper incorporates the well-posed model reference adaptive control with integral state feedback and a modern anti-windup scheme to present an appropriate performance in practical conditions of an AUV. Stability of the proposed method is analyzed by Lyapunov theory. Then, the proposed controller is implemented in the hardware in the loop simulation of AUV. For this purpose, the introduced method is implemented in an onboard computer to be checked in a real-time dynamic simulation environment. Obtained results in the presence of real hardware of system, actuators, computational delays and real-time execution verify the effectiveness of proposed scheme. 相似文献
16.
To predict the concentration of oxygen in the Sea of Azov, the paper relies on the decomposition of this parameter by a system
of empirical orthogonal functions and on the prediction of decomposition coefficients via a grouped consideration of arguments.
This method is applied to construct an optimal model for predicting the spatial distribution of oxygen in various seasons
of the year, using a data on the mean seasonal dissolved oxygen concentration compiled at 32 reference stations occupied from
1958 to 1988. The experimentally derived numerical data indicate that the method can be effectively used to make short-term
predictions.
Translated by Vladimir A. Puchkin. 相似文献
17.
This paper presents a method to calculate finite-time Lyapunov exponents (FTLEs) for experimental time series using numerical simulation to approximate the local Jacobian of the system at each time step. This combined numerical–experimental approach to the calculation of FTLE is applicable to any physical system which can be numerically approximated. By way of example, the method is applied to the problem of vessel capsize. 相似文献
18.
An Oscillating Water Column (OWC) device can output energy through reciprocating or unidirectional airflow. The unidirectional airflow is helpful to utilize a simple and high-efficiency unidirectional air turbine. The pentagonal BBDB proposed by us based on OWC principle can be regarded as a floating Oscillating Body and its Power Take-Off (PTO) consists of a chamber, a water column, a turbine and a generator. The Capture Width Ratio (CWR) of the pentagonal BBDB model with the reciprocating and unidirectional airflow was studied in this paper. The wave flume test results indicate the mean CWR of the pentagonal BBDB model with reciprocating airflow can reach up to 121.91% and the mean CWR of the model with unidirectional airflow could reach 100.94% during the whole wave cycle in regular waves. For irregular waves, the mean CWR of the model with the unidirectional airflow is as high as 62.83% during the whole wave cycle. Hopefully, the combination of the pentagonal BBDB with the check valve to output power during the air exhalation and conventional high-efficiency unidirectional turbine will improve the total efficiency of the BBDB. 相似文献
19.
This paper studies the chaotic behaviours of a relative rotation nonlinear dynamical system under parametric excitation and its control. The dynamical equation of relative rotation nonlinear dynamical system under parametric excitation is deduced by using the dissipation Lagrange equation. The criterion of existence of chaos under parametric excitation is given by using the Melnikov theory. The chaotic behaviours are detected by numerical simulations including bifurcation diagrams, Poincaré map and maximal Lyapunov exponent. Furthermore, it implements chaotic control using non-feedback method. It obtains the parameter condition of chaotic control by the Melnikov theory. Numerical simulation results show the consistence with the theoretical analysis. The chaotic motions can be controlled to period-motions by adding an excitation term. 相似文献
20.
Physical Investigation of Directional Wave Focusing and Breaking Waves in Wave Basin 总被引：3，自引：1，他引：3
An experimental scheme for the generation of directional focusing waves in a wave basin is established in this paper. The effects of the directional range, frequency width and center frequency on the wave focusing are studied. The distrihution of maximum amplitude and the evolution of time series and spectra during wave packet propagation and the variation of water surface parameters are extensively investigated. The results reveal that the characteristics of focusing waves are significantly influenced hy wave directionality and that that breaking criteria for directional waves are distinctly different from those for unidirectional waves. 相似文献