期刊文献+
共找到16篇文章
< 1 >
每页显示 20 50 100
ACTIVE CONTROL OF A FLEXIBLE CANTILEVER PLATE WITH MULTIPLE TIME DELAYS 被引量:1
1
作者 Longxiang Chen Ji Pan Guoping Cai 《Acta Mechanica Solida Sinica》 SCIE EI 2008年第3期257-266,共10页
Active control of a flexible cantilever plate with multiple time delays is investigated using the discrete optimal control method. A controller with multiple time delays is presented. In this controller, time delay ef... Active control of a flexible cantilever plate with multiple time delays is investigated using the discrete optimal control method. A controller with multiple time delays is presented. In this controller, time delay effect is incorporated in the mathematical model of the dynamic system throughout the control design and no approximations and assumptions are made in the controller derivation, so the system stability is easily guaranteed. Furthermore, this controller is available for both small time delays and large time delays. The feasibility and efficiency of the proposed controller are verified through numerical simulations in the end of this paper. 展开更多
关键词 flexible cantilever plate multiple time delays discrete optima l control
下载PDF
Design method of multiple time-delay controller for active structural vibration control
2
作者 陈龙祥 蔡国平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2009年第11期1405-1414,共10页
An optimal control method for seismic-excited building structures with multiple time delays is investigated in this paper. The system state equation with multiple time delays is discretized and transformed into a stan... An optimal control method for seismic-excited building structures with multiple time delays is investigated in this paper. The system state equation with multiple time delays is discretized and transformed into a standard discrete form without any explicit time delay by a particular augmenting for state variables. A time-delay controller is then designed based on this standard equation using the discrete optimal control method. Effectiveness of the proposed controller is demonstrated by numerical simulations. Simulation results indicate that a very small time delay may result in the instability of the control system if it is not compensated in the control design. Time delay may be compensated effectively by the proposed controller, in the mean time, an effective control may be obtained. The proposed controller is valid for both small and large time delays. 展开更多
关键词 building structures active control multiple time delays
下载PDF
Multiple Lagrange stability and Lyapunov asymptotical stability of delayed fractional-order Cohen-Grossberg neural networks
3
作者 Yu-Jiao Huang Xiao-Yan Yuan +2 位作者 Xu-Hua Yang Hai-Xia Long Jie Xiao 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第2期196-205,共10页
This paper addresses the coexistence and local stability of multiple equilibrium points for fractional-order Cohen-Grossberg neural networks(FOCGNNs)with time delays.Based on Brouwer's fixed point theorem,sufficie... This paper addresses the coexistence and local stability of multiple equilibrium points for fractional-order Cohen-Grossberg neural networks(FOCGNNs)with time delays.Based on Brouwer's fixed point theorem,sufficient conditions are established to ensure the existence of Πi=1^n(2Ki+1)equilibrium points for FOCGNNs.Through the use of Hardy inequality,fractional Halanay inequality,and Lyapunov theory,some criteria are established to ensure the local Lagrange stability and the local Lyapunov asymptotical stability of Πi=1^n(Ki+1)equilibrium points for FOCGNNs.The obtained results encompass those of integer-order Hopfield neural networks with or without delay as special cases.The activation functions are nonlinear and nonmonotonic.There could be many corner points in this general class of activation functions.The structure of activation functions makes FOCGNNs could have a lot of stable equilibrium points.Coexistence of multiple stable equilibrium points is necessary when neural networks come to pattern recognition and associative memories.Finally,two numerical examples are provided to illustrate the effectiveness of the obtained results. 展开更多
关键词 FRACTIONAL-ORDER COHEN-GROSSBERG neural networks multiple LAGRANGE STABILITY multiple LYAPUNOV asymptotical STABILITY time delays
下载PDF
Cascade control based on minimum sensitivity in outer loop for processes with time delay 被引量:6
4
作者 尹成强 惠鸿忠 +2 位作者 岳继光 高洁 郑丽萍 《Journal of Central South University》 SCIE EI CAS 2012年第9期2689-2696,共8页
A new cascade control program was proposed based on modified internal model control to handle stable,unstable and integrating processes with time delay.The program had totally four controllers of which the secondary l... A new cascade control program was proposed based on modified internal model control to handle stable,unstable and integrating processes with time delay.The program had totally four controllers of which the secondary loop had two controllers and the primary loop had two controllers.The two secondary loop controllers were designed using IMC technique.They were decoupled completely and could be adjusted independently,which avoided the undesirable influence on performance of the primary controllers.The main controller in the primary loop was devised as a PID using the method of minimum sensitivity,which could guarantee not only the nominal performance but also the robust stability of the system.A setpoint filter was added in the primary loop to improve the tracking performance.All the controllers of the two closed-loops were designed analytically,and could be adjusted and optimized by single parameter respectively.Simulations were carried out on three various processes with time delay,and the results show that the proposed method can provide a better performance of both set-point tracking and disturbance rejection and robustness against parameters perturbation. 展开更多
关键词 cascade control time delay H∞ performance specification modified internal mode control multiple degrees of freedom
下载PDF
Position and Velocity Time Delay for Suppression Vibrations of a Hybrid Rayleigh-Van der Pol-Duffing Oscillator 被引量:3
5
作者 Y.A.Amer A.T.El-Sayed M.N.Abd El-Salam 《Sound & Vibration》 EI 2020年第3期149-161,共13页
In this paper,we used time delay feedback to minimize the vibrations of a hybrid Rayleigh–van der Pol–Duffing oscillator.This system is a one-degree-offreedom containing the cubic and fifth nonlinear terms and an ex... In this paper,we used time delay feedback to minimize the vibrations of a hybrid Rayleigh–van der Pol–Duffing oscillator.This system is a one-degree-offreedom containing the cubic and fifth nonlinear terms and an external force.We applied the multiple scales method to get the solution from first approximation.Graphically and numerically,we studied the system before and after adding time delay feedback at the primary resonance case(ffi!).We used MATLAB program to simulate the efficacy of different parameters and the time delay on the main system. 展开更多
关键词 Position time delay feedback velocity time delay feedback multiple scales method resonance cases
下载PDF
Duffing Oscillator’s Vibration Control under Resonance with a Negative Velocity Feedback Control and Time Delay
6
作者 Y.A.Amer Taher A.Bahnasy 《Sound & Vibration》 EI 2021年第3期191-201,共11页
An externally excited Duffing oscillator under feedback control is discussed and analyzed under the worst resonance case.Multiple time scales method is applied for this system to find analytic solution with the existe... An externally excited Duffing oscillator under feedback control is discussed and analyzed under the worst resonance case.Multiple time scales method is applied for this system to find analytic solution with the existence and nonexistence of the time delay on control loop.An appropriate stability analysis is also performed and appropriate choices for the feedback gains and the time delay are found in order to reduce the amplitude peak.Different response curves are involved to show and compare controller effects.In addition,analytic solutions are compared with numerical approximation solutions using Rung-Kutta method of fourth order. 展开更多
关键词 Non-linear dynamical system multiple time scales method active feedback controller time delay
下载PDF
Bifurcation and Stability Analysis of HIV Infectious Model with Two Time Delays
7
作者 S. Q. Ma 《International Journal of Modern Nonlinear Theory and Application》 2021年第2期49-64,共16页
The HIV problem is studied by version of delay mathematical models which consider the apoptosis of uninfected CD4<sup>+</sup> T cells which cultured with infected T cells in big volume. The opportunistic i... The HIV problem is studied by version of delay mathematical models which consider the apoptosis of uninfected CD4<sup>+</sup> T cells which cultured with infected T cells in big volume. The opportunistic infection and the apoptosis of uninfected CD4<sup>+</sup> T cells are caused directly or indirectly by a toxic substance produced from HIV genes. Ubiquitously, the nonlinear incidence rate brings forth the increasing number of infected CD4<sup>+</sup> T cells with introduction of small time delay, and in addition, there also exists a natural time delay factor during the process of virus replication. With state feedback control of time delay, the bifurcating periodical oscillating phenomena is induced via Hopf bifurcation. Mathematically, with the geometrical criterion applied in the stability analysis of delay model, the critical threshold of Hopf bifurcation in multiple delay differential equations which satisfy the transversal condition is derived. By applying reduction dimensional method combined with the center manifold theory, the stability of the bifurcating periodical solution is analyzed by the perturbation near Hopf point. 展开更多
关键词 Hopf Bifurcation multiple time delay HIV Model
下载PDF
Robust stability analysis of switched uncertain systems with multiple time-varying delays and actuator failures 被引量:4
8
作者 Wang, Limin Shao, Cheng 《控制理论与应用(英文版)》 EI 2011年第2期267-272,共6页
In this paper,the robust stability issue of switched uncertain multidelay systems resulting from actuator failures is considered.Based on the average dwell time approach,a set of suitable switching signals is designed... In this paper,the robust stability issue of switched uncertain multidelay systems resulting from actuator failures is considered.Based on the average dwell time approach,a set of suitable switching signals is designed by using the total activation time ratio between the stable subsystem and the unstable one.It is first proven that the resulting closed-loop system is robustly exponentially stable for some allowable upper bound of delays if the nominal system with zero delay is exponentially stable under these switching laws.Particularly,the maximal upper bound of delays can be obtained from the linear matrix inequalities.At last,the effectiveness of the proposed method is demonstrated by a simulation example. 展开更多
关键词 Robustly exponential stability Actuator failures Average dwell time Switched systems Linear matrix inequalities multiple time-varying delays
原文传递
Robust Finite-Time Guaranteed Cost Control for Positive Systems with Multiple Time Delays 被引量:2
9
作者 THUAN Mai Viet 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2019年第2期496-509,共14页
This paper deals with the finite-time guaranteed cost control problem for positive system with multiple time delays and bounded disturbance. By using Lyapunov-Krasovskii functional method,some new sufficient condition... This paper deals with the finite-time guaranteed cost control problem for positive system with multiple time delays and bounded disturbance. By using Lyapunov-Krasovskii functional method,some new sufficient conditions for the design of a state feedback controller which makes the closedloop system finite-time stable and guarantees an adequate cost level of performance are derived. Two numerical examples are also given to show the effectiveness of the proposed method. 展开更多
关键词 FINITE-time guaranteed COST control linear matrix INEQUALITIES LYAPUNOV-KRASOVSKII functional multiple time delayS POSITIVE systems
原文传递
Multiple resonances with time delays in scale-free networks of Hodgkin-Huxley neurons subjected to non-Gaussian noise 被引量:2
10
作者 HAO YingHang GONG YuBing LIN Xiu WANG Li 《Science China Chemistry》 SCIE EI CAS 2011年第5期782-787,共6页
The spiking behavior with varying time delay in scale-free networks of Hodgkin-Huxley neurons with non-Gaussian noise has been studied,and the effect of non-Gaussian noise on the delay-induced spiking behavior is disc... The spiking behavior with varying time delay in scale-free networks of Hodgkin-Huxley neurons with non-Gaussian noise has been studied,and the effect of non-Gaussian noise on the delay-induced spiking behavior is discussed. It was found that multiple spatio-temporal resonances occur when the delay lengths are integer multiples of the spiking periods,and the resonances may be strengthened when the non-Gaussian noise is appropriate. This result shows that time delays can optimize the spiking temporal regularity and spatial synchronization,and appropriate non-Gaussian noise may enhance the delay-induced spiking behaviors. Our findings may help to further understand the joint roles of non-Gaussian noise and time delays in the spiking activity of scale-free neuronal networks. 展开更多
关键词 NEURON time delay non-Gaussian noise multiple resonances scale-free network
原文传递
EXISTENCE OF MULTIPLE PERIODIC SOLUTIONS TO LOTKA-VOLTERRA NETWORK-LIKE FOOD-CHAIN SYSTEM WITH DELAYS AND IMPULSES ON TIME SCALES 被引量:1
11
作者 KAIHONG ZHAO LIANG DING FENGZAO YANG 《International Journal of Biomathematics》 2014年第1期39-68,共30页
In this paper, we have studied a general kind of n-species Lotka-Volterra network- like food-chain system with delays and impulses on time scales. Applying Mawhin's continuation theorem of coincidence degree theory a... In this paper, we have studied a general kind of n-species Lotka-Volterra network- like food-chain system with delays and impulses on time scales. Applying Mawhin's continuation theorem of coincidence degree theory and some skills of inequalities, some sufficient criteria have been established to guarantee the existence of at least 2n periodic solutions to this model. One example is given to illustrate the effectiveness of our results. 展开更多
关键词 time scales network-like food-chain system coincidence degree multiple periodic solutions time delays and impulses
原文传递
A Practical Method for Improving Delay Performance of Time Slot Allocation in DVB-RCS
12
作者 秦勇 张军 +1 位作者 张涛 董启甲 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2009年第2期174-183,共10页
In digital video broadcasting and return channel via satellite (DVB-RCS) systems, the time slot location assigned to a given traffic in multiple frequency-time division multiple access (MF-TDMA) frame has significant ... In digital video broadcasting and return channel via satellite (DVB-RCS) systems, the time slot location assigned to a given traffic in multiple frequency-time division multiple access (MF-TDMA) frame has significant effects upon the traffic delay per- formance. This article proposes models to analyze the relationships among frame length, bandwidth assignment (assigned time slot count), time slot location in frame, and traffic delay performance for traffics of constant bit rate (CBR) and variable bit rate (... 展开更多
关键词 satellite communication systems time division multiple access DVB-RCS time slot allocation MODELS delay
原文传递
Novel Channel Estimation Method in Broadband MIMO-OFDM Systems 被引量:1
13
作者 焦慧颖 安建平 《Journal of Beijing Institute of Technology》 EI CAS 2007年第3期290-294,共5页
A least square (IS) parametric channel estimation method in broadband mt/ltiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems is proposed. The mean square error (MSE) p... A least square (IS) parametric channel estimation method in broadband mt/ltiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems is proposed. The mean square error (MSE) performance using optimal training pilots is also given, which proves the method can improve the estimation precision greatly in sparse channel.. Since such method needs the multi-path time delays information of the channel, the probabilistic data association (PDA) method is employed to estimate the time delay of each path. Simulation results show that both the bit error rate (BER) and the MSE performance of the proposed method are better than the traditional LS channel estimation method. 展开更多
关键词 multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) channel estimation parametric channel model time delay estimation
下载PDF
Selection of Embedding Dimension and Delay Time in Phase Space Reconstruction 被引量:1
14
作者 MA Hong-guang HAN Chong-zhao 《Frontiers of Electrical and Electronic Engineering in China》 CSCD 2006年第1期111-114,共4页
A new algorithm is proposed for computing the embedding dimension and delay time in phase space reconstruction.It makes use of the zero of the nonbias multiple autocorrelation function of the chaotic time series to de... A new algorithm is proposed for computing the embedding dimension and delay time in phase space reconstruction.It makes use of the zero of the nonbias multiple autocorrelation function of the chaotic time series to determine the time delay,which efficiently depresses the computing error caused by tracing arbitrarily the slop variation of average displacement(AD)in AD algorithm.Thereafter,by means of the iterative algorithm of multiple autocorrelation andΓtest,the near-optimum parameters of embedding dimension and delay time are estimated.This algorithm is provided with a sound theoretic basis,and its computing complexity is relatively lower and not strongly dependent on the data length.The simulated experimental results indicate that the relative error of the correlation dimension of standard chaotic time series is decreased from 4.4%when using conventional algorithm to 1.06%when using this algorithm.The accuracy of invariants in phase space reconstruction is greatly improved. 展开更多
关键词 phase space reconstruction embedding dimension delay time multiple autocorrelation Γtest
原文传递
Robust Stability Analysis of a Kind of Combined Integrating Control System
15
作者 任正云 贾永基 《Journal of Donghua University(English Edition)》 EI CAS 2009年第4期397-401,共5页
This paper offeres an exact study on the robust stability of a kind of combined integrating control system, and the robust stability belongs to the analysis of a kind of quasi-polynomial with two independent time dela... This paper offeres an exact study on the robust stability of a kind of combined integrating control system, and the robust stability belongs to the analysis of a kind of quasi-polynomial with two independent time delays. The parameters of stable space under time delay uncertainty are fixed after Rekasius transformation, and then a new cluster treatment of characteristic roots (CTCR) procedure is adopted to determine the stable space. By this strategy we find that the unstable space is not continuous and both Karitonov vertices theory and Edge theory are unable to be extended to quasi-polynomial under time delay uncertainty. 展开更多
关键词 combined integrating control system robust stability quasi-polynomial multiple time delay
下载PDF
Efficient Time Synchronization Approach for Wireless Communication Systems on GPP-Based Software-Defined Radio Platform 被引量:2
16
作者 黄伊 唐超 +3 位作者 段红亮 周一青 钱蔓藜 黄亮 《Journal of Computer Science & Technology》 SCIE EI CSCD 2013年第3期429-436,共8页
General purpose processer (GPP) based software-defined radio (SDR) platforms provide wireless communication system engineers with maximal architecture flexibility and versatility to construct a wideband wireless c... General purpose processer (GPP) based software-defined radio (SDR) platforms provide wireless communication system engineers with maximal architecture flexibility and versatility to construct a wideband wireless communication system. Nevertheless, the lack of hardware real-time timing control makes it difficult to achieve time synchronization between the base station and the terminals. In this paper, a software-based time synchronization (STS) method is proposed to realize the time synchronization of time division multiple access (TDMA) based wireless communication systems. A high precision software clock source is firstly constructed to measure the elapse of processing time. The Round-Trip Delay (RTD) algorithm is then presented to calculate timing advance values and achieve time synchronization. An example TDMA system is implemented on Microsoft Sora platforms to evaluate is effective to enable time synchronization for wideband the performance. Experiments show that the proposed mechanism wireless communication systems on GPP-based SDR platforms. 展开更多
关键词 round-trip delay algorithm software-defined radio time division multiple access time synchronization
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部