In this paper, we investigate the locally and globally adaptive synchronization problem for an uncertain complex dynamical network with time-varying coupling delays based on the decentralized control. The coupling terms here are bounded by high-order polynomials with known gains that are ubiquitous in a large class of complex dynamical networks. We generalize the usual technology of searching for an appropriate coordinates transformation to change the network dynamics into a series of decoupled lower-dimensional systems. Several adaptive synchronization criteria are derived by constructing the Lyapunov-Krasovskii functional and Barbalat lemma, and the proposed criteria are simple in form and convenient for the practical engineering design. Numerical simulations illustrated by a nearest-neighbor coupling network verify the effectiveness of the proposed synchronization scheme.
This paper deals with the problem of switching between an open-loop estimator and a close-loop estimator for compensating transmission error and packet dropout of networked control systems. Switching impulse is considered in order to reduce the error between theory and application, a sufficient condition for exponential stabilization of networked control systems under a given switching rule is presented by multiple Lyapunov-like functions. These results are presented for both continuous-time and discrete-time domains. Controllers are designed by means of linear matrix inequalities. Sim- ulation results show the feasibility and efficiency of the proposed method.
A model of uncertain switched fuzzy systems whose subsystems are uncertain fuzzy systems is presented. Robust controllers for a class of switched fuzzy systems are designed by using the Lyapunov function method. Stability conditions for global asymptotic stability are developed and a switching strategy is proposed. An example shows the effectiveness of the method.
The problem of adaptive robust control is addressed for a class of neutral delay systems. All uncertainties are assumed to be bounded by unknown constants. An improved adaptation law is proposed to estimate the square of these unknown bounds. Then, by making use of the updated values of the squared unknown bounds, an adaptive controller is designed to make the solution of the resultant closed-loop system uniformly ultimately bounded. Furthermore, this method avoids chattering and improves the performance. An example is given to illustrate the effectiveness of this method.
研究了含有参数不确定性及外部扰动的TCSC(thyristor controlled series compensation)单机无穷大母线系统的鲁棒H∞控制问题,使用自适应backstepping方法及Lyapunov方法构造出系统的存贮函数,同时设计出鲁棒H∞控制器及参数替换律.在内部扰动中同时考虑了阻尼系数不易精确测量和发电机电势不可直接测量的影响.该控制器不仅保留系统的非线性特性和对未知参数的实时在线估计,而且能够有效抑制干扰对系统输出的影响.仿真结果表明,所设计的控制器能够快速抑制振荡,保证单机无穷大系统的暂态稳定.
针对带有TCSC(Thyristor Controlled Series Compensation)的单机无穷大总线系统的非线性二阶模型,使用自适应动态面方法设计了TCSC的非线性控制器.此设计方法,无须对原系统进行线性化,并能保证闭环误差系统渐进稳定,对于系统中的参数不确定性,具有较强的鲁棒性和自适应性.此控制器简单易于实现,其有效性通过仿真实例获得了验证.
