Faculty of Electrical Engineering, Gonabad Branch, Islamic Azad University, Gonabad 6518115743, Iran.
Biomedical Data Acquisition Lab (BDAL), Faculty of Electrical Engineering, K. N. Toosi University of Technology, Tehran 1996715433, Iran.
Sensors (Basel). 2021 Jan 2;21(1):254. doi: 10.3390/s21010254.
In this paper, the multi-state synchronization of chaotic systems with non-identical, unknown, and time-varying delay in the presence of external perturbations and parametric uncertainties was studied. The presence of unknown delays, unknown bounds of disturbance and uncertainty, as well as changes in system parameters complicate the determination of control function and synchronization. During a synchronization scheme using a robust-adaptive control procedure with the help of the Lyapunov stability theorem, the errors converged to zero, and the updating rules were set to estimate the system parameters and delays. To investigate the performance of the proposed design, simulations have been carried out on two Chen hyper-chaotic systems as the slave and one Chua hyper-chaotic system as the master. Our results showed that the proposed controller outperformed the state-of-the-art techniques in terms of convergence speed of synchronization, parameter estimation, and delay estimation processes. The parameters and time delays were achieved with appropriate approximation. Finally, secure communication was realized with a chaotic masking method, and our results revealed the effectiveness of the proposed method in secure telecommunications.
本文研究了存在外部扰动和参数不确定性时非相同、未知和时变时滞混沌系统的多态同步。未知时滞、未知干扰和不确定性的界限以及系统参数的变化使得控制函数和同步的确定变得复杂。在使用鲁棒自适应控制程序和李雅普诺夫稳定性定理的同步方案中，误差收敛到零，并且设置更新规则来估计系统参数和延迟。为了研究所提出设计的性能，在两个 Chen 超混沌系统作为从系统和一个 Chua 超混沌系统作为主系统上进行了仿真。我们的结果表明，所提出的控制器在同步的收敛速度、参数估计和延迟估计过程方面优于最新技术。参数和时滞通过适当的逼近得到。最后，通过混沌掩蔽方法实现了安全通信，我们的结果表明了所提出的方法在安全电信中的有效性。
