李善强 彭秀艳 李强
关键词:混沌系统;时变时滞;有限时间同步;自适应控制
DOI:10.15938/j.emc.2019.06.000
中图分类号文献标志码:A 文章编号:1007 -449X(2019)06 -0000 -00
Abstract:In this paper, the issue of adaptive finitetime synchronization of multiple chaotic systems with timevarying delay is investigated. The chaotic systems with different structures and timevarying state delays are considered. Firstly, by designing appropriate adaptive update law, the gain of the controller can be updated online to achieve faster convergence speed. The design method of adaptive controller is presented. Then by using Lyapunov stability theorem and finitetime stability theory, it is proved that the designed adaptive controller and the corresponding control gain adaptive update law can guarantee the synchronization of states of multiple error dynamic systems in finite time, and the estimation of synchronization settling time is also given. Finally, the feasibility and effectiveness of the proposed adaptive finitetime synchronization control method is further validated by numerical simulation of three typical chaotic systems i.e. Lorenz system, Chen system and Lü system.
Keywords:chaotic systems; timevarying delay; finitetime synchronization; adaptive control
0 引 言
混沌系统同步问题具有广阔的工程应用前景,例如物理、生物和信息科学以及混沌系统的同步在保密通信领域中起着重要作用[1-2]。因此,近年来混沌系统的同步控制问题得到研究者的广泛关注。最初,研究者只是研究兩个混沌系统的同步控制问题,例如文献[3]研究了两个时变时滞混沌神经网络的有限时间同步控制问题。随后,具有时变时滞和有界扰动的混沌系统的有限时间同步控制已在文献[4]中讨论。文献[5-6]研究了混沌系统的自适应有限时间同步问题。文献[7]研究了两个时滞混沌神经网络的间歇同步控制问题。两个不同的具有时变时滞混沌系统的投影同步在文献[8]中被研究。利用脉冲控制方法,文献[9]对混沌系统的延迟同步进行了分析。而文献[10]针对带有执行器故障的不确定混沌系统,研究了鲁棒自适应容错同步问题。对于两个混沌系统的同步,相对简单。而且,很多文献都是假设两个混沌系统的结构完全相同,在不同初始条件下,使得驱动系统和响应系统达到同步。
对于多个时滞混沌系统的同步控制研究变得越来越复杂,且面临着更大的挑战。文献[11-14]研究了多个混沌系统同步控制问题,但是这些文献均没有考虑系统的时变时滞现象。因此,关于具有时变时滞的多个结构不同的混沌系统的有限时间同步控制是一个较复杂的研究问题,目前尚未见有关研究结果。
基于上述分析,本文研究了多个时滞混沌系统的有限时间同步控制问题。文章的主要贡献如下:1)多个混沌系统具有不同的结构;2)给出了自适应控制器和自适应律的设计方法;3)引入投影比例因子,研究多个混沌系统的投影同步控制。适当地选择投影因子,可知投影同步包括了通常的完全同步问题;4)给出了保证多个时滞混沌系统达到有限时间同步的充分条件。
4 结 论
研究了多个不同的具有时变时滞的混沌系统的有限时间投影同步问题。利用自适应控制的方法设计了有限时间同步自适应控制器。根据Lyapunov稳定性定理和有限时间稳定理论证明了所提自适应控制器可以保证多个的混沌系统有限时间投影同步。最后,通过算例仿真验证了自适应控制器的可行性和有效性。
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