Stabilization and synchronization of chaotic systems with mixed time-varying delays via intermittent control with non-fixed both control period and control width

2015 ◽  
Vol 154 ◽  
pp. 61-69 ◽  
Author(s):  
Qiankun Song ◽  
Tingwen Huang
Keyword(s):  
Chaotic Systems ◽  
Control Period ◽  
Intermittent Control ◽  
Time Varying ◽  
And Control

scholarly journals Robust Synchronization of Class Chaotic Systems Using Novel Time-Varying Gain Disturbance Observer-Based Sliding Mode Control

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yang Wang ◽  
Zhen Wang ◽  
Lingyun Kong
Keyword(s):  
Sliding Mode Control ◽  
Disturbance Observer ◽  
Chaotic Systems ◽  
Sliding Mode ◽  
High Gain ◽  
Time Varying ◽  
Mode Control ◽  
Control Precision ◽  
Robust Synchronization ◽  
And Control

For synchronization of a class of chaotic systems in the presence of nonvanishing uncertainties, a novel time-varying gain observer-based sliding mode control is proposed. First, a novel time-varying gain disturbance observer (TVGDO) is developed to estimate the uncertainties. Then, by using the output of TVGDO to modify sliding mode control (SMC), a new TVGDO-based SMC scheme is developed. Although the observation and control precision of conventional fixed gain disturbance observer-based control (FGDOC) for chaotic systems can be guaranteed by a high observer gain, the undesirable spike problem may be caused by the high gain if the initial values of estimate and true states are not equal. The most attractive feature of this work is that the newly proposed TVGDO can eliminate the spike problem by developing a time-varying gain scheme. Finally, the effectiveness of the proposed method is demonstrated by the numerical simulation.

New results on synchronization of chaotic systems with time-varying delays via intermittent control

2011 ◽  
Vol 67 (1) ◽  
pp. 393-402 ◽  
Author(s):  
Shuiming Cai ◽  
Junjun Hao ◽  
Qinbin He ◽  
Zengrong Liu
Keyword(s):  
Chaotic Systems ◽  
Intermittent Control ◽  
Time Varying

Synchronization of Chaotic Systems with Time Delays via Periodically Intermittent Control

2017 ◽  
Vol 26 (09) ◽  
pp. 1750139 ◽  
Author(s):  
Chao Liu ◽  
Zheng Yang ◽  
Dihua Sun ◽  
Xiaoyang Liu ◽  
Wanping Liu
Keyword(s):  
Time Delay ◽  
Time Delays ◽  
Chaotic Systems ◽  
Control Period ◽  
Feasible Region ◽  
Intermittent Control ◽  
Periodically Intermittent Control ◽  
First Order ◽  
Response System ◽  
System With Time Delay

This paper investigates the exponential synchronization of chaotic systems with time delays via periodically intermittent control. Under the new differential inequality, some novel synchronization criteria are derived. In contrast to the existing works, the proposed results are less conservative because they can obtain more precise synchronized rate under the identical control conditions and remove the restrictions on the control period (or the control width) and the time delay. By using special parameters, the feasible region D(ξ), which guarantees the response system synchronizes with the drive system with synchronized rate 0.5ξ, is obtained. The Lu chaotic attractor and a first-order chaotic system with time delay are presented to demonstrate the effectiveness of the proposed results.

Synchronization of Chaotic Systems with Uncertain Time-Varying Parameters

2015 ◽  
Vol 9 (6) ◽  
pp. 568
Author(s):  
Ahmad Al-Jarrah ◽  
Mohammad Ababneh ◽  
Suleiman Bani Hani ◽  
Khalid Al-Widyan
Keyword(s):  
Chaotic Systems ◽  
Time Varying ◽  
Varying Parameters ◽  
Time Varying Parameters ◽  
Uncertain Time

scholarly journals Heterogeneity and effectiveness analysis of COVID-19 prevention and control in major cities in China through time-varying reproduction number estimation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qing Cheng ◽  
Zeyi Liu ◽  
Guangquan Cheng ◽  
Jincai Huang
Keyword(s):  
Prevention And Control ◽  
Large Scale ◽  
Reproduction Number ◽  
Correlation Method ◽  
Control Measures ◽  
Time Varying ◽  
Short Period ◽  
Significant Difference ◽  
Prevention And Control Measures ◽  
And Control

AbstractBeginning on December 31, 2019, the large-scale novel coronavirus disease 2019 (COVID-19) emerged in China. Tracking and analysing the heterogeneity and effectiveness of cities’ prevention and control of the COVID-19 epidemic is essential to design and adjust epidemic prevention and control measures. The number of newly confirmed cases in 25 of China’s most-affected cities for the COVID-19 epidemic from January 11 to February 10 was collected. The heterogeneity and effectiveness of these 25 cities’ prevention and control measures for COVID-19 were analysed by using an estimated time-varying reproduction number method and a serial correlation method. The results showed that the effective reproduction number (R) in 25 cities showed a downward trend overall, but there was a significant difference in the R change trends among cities, indicating that there was heterogeneity in the spread and control of COVID-19 in cities. Moreover, the COVID-19 control in 21 of 25 cities was effective, and the risk of infection decreased because their R had dropped below 1 by February 10, 2020. In contrast, the cities of Wuhan, Tianmen, Ezhou and Enshi still had difficulty effectively controlling the COVID-19 epidemic in a short period of time because their R was greater than 1.

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