一类周期切换控制稳定的算法设计

利用切换控制及凸组合弱化控制系统稳定性条件,使组合和满足Hurwitz条件而实现切换稳定。该文对切换系统的表达形式、切换信号及切换路径、切换收敛、稳定性判断准则及周期切换特征进行了分析。针对无扰动或扰动切换系统进行周期稳定性设计,提出3种切换控制率及对应的切换算法。通过对交通实例进行仿真设计,比对切换实验数据,反映出不同切换率稳定和收敛情况,通过上述算法实现系统的周期稳定。     

基于观测器的切换模糊时滞系统的反馈控制

针对状态不可测的切换模糊时滞系统, 根据平行分布补偿算法(PDC), 设计了切换模糊观测器和反馈控制器, 应用共同Lyapunov函数方法使观测误差系统在任意切换下渐近稳定, 应用多Lyapunov函数方法, 使系统状态在设计切换律下渐近稳定, 并给出了时滞相关的切换模糊系统渐近稳定的矩阵不等式条件. 仿真结果表明结论的有效性.     

控制器失效的容错切换律设计

针对所有控制器同时失效的情况,研究系统容错切换律的设计问题,发展了圆锥切换律,分析了系统稳定的充分条件,通过在不稳定控制器之间切换来保证系统稳定的控制效果。基于系统的状态和子系统的运动方向选择控制器,可保证系统具有最快的收敛速度。对于子系统同向和逆向的系统分别作了数值仿真,验证了结论的有效性。     

基于联合误差控制的变步长双模盲均衡算法研究

针对CMA+DDLMS双模式盲均衡算法对相位不敏感、收敛速度慢、突然切换容易造成误码率升高以及算法不稳定等问题,提出一种基于联合误差控制的变步长双模切换盲均衡算法。与现有双模式算法相比,新算法引入变步长因子有效提高算法收敛速度,同时采用联合绝对剩余误差和判决区域控制的双模切换保证算法的稳健性。采用16QAM系统的仿真结果表明,新算法具有抗干扰能力强、收敛精度高和收敛速度快等特点。     

分段可压缩路径的切换优化算法

针对切换控制系统可渐近稳定的充分条件的难题,提出了一种分段可压缩路径的搜索算法。分析了压缩路径的切换控制规律,并对常规可压缩路径的切换控制进行了优化,提出了最短和加权平均可压缩优化路径算法及峰值控制优化算法。通过实例Matlab程序仿真寻找可压缩路径的优化参数,比对切换实验数据,演示不同优化算法下的切换率稳定和收敛状况。     

一类线性离散切换系统的迭代学习控制

考虑具有任意切换序列线性离散切换系统的迭代学习控制问题. 假设切换系统在有限时间区间内重复运行, P型ILC算法可实现该类系统在整个时间区间内的完全跟踪控制. 采用超向量方法给出了算法在迭代域内收敛的条件, 并在理论上分析了的收敛性. 仿真示例验证了理论的结果.     

网络环境下切换模糊时滞系统的非脆弱控制

针对一类控制器增益存在摄动的非线性网络切换系统,在系统同时存在随机时变时滞和不确定性的情况下,采用T-S模型建模,研究系统的稳定控制问题。利用平均驻留时间(ADT)法设计系统的切换律及非脆弱状态反馈控制器,并给出网络切换模糊时滞系统指数稳定的平均驻留时间条件。结合李雅普诺夫函数(LKF)法,推导时滞相关的网络切换模糊系统指数稳定的矩阵不等式条件,并将此条件转化为线性矩阵不等式形式。通过数值仿真对比系统在采用ADT法与传统LKF法下的状态曲线,结果表明,ADT法可以使系统收敛速度更快,性能指标更好。     

一类切换模糊时滞系统的状态反馈控制

针对切换模糊时滞系统,根据平行分布补偿算法,设计了模糊状态反馈控制器.使用切换技术及单Lyapunov函数和多Lyapunov函数方法,给出了这一类切换模糊时滞系统渐近稳定的充分条件及切换律.仿真结果表明了方法的有效性.     

区间切换系统的状态观测器设计

讨论一类区间切换系统状态观测器的设计问题。采用共同Lyapunov函数方法、多Lyapunov函数方法,设计出状态观测器和相应的切换策略,以线性矩阵不等式的形式给出保证误差系统渐近稳定的充分条件。仿真算例验证状态观测器的有效性。     

一类时滞切换系统的输入-状态稳定性分析

利用多Lyapunov函数方法、驻留时间法和Gronwall-Bellman不等式研究了一类时滞切换系统的输入-状态稳定性分析问题．从系统输入-状态稳定定义出发,给出了使得一类时滞切换系统输入-状态稳定的充分条件．与已有的方法相比,无需同时满足构造输入-状态稳定控制Lyapunov函数和所有子系统都是输入-状态稳定的条件,为控制器的设计提供了便利．最后,通过算例仿真验证了所提出方法的可行性．     

Reachable sets of second-order switched systems

This paper studies the reachability of second-order switched nonlinear systems in which the switching law is the only control action. For some initial conditions we find states that are reachable from the initial condition. We also give the switching law that drives the system from the initial state to the final state. Moreover, for switched systems with limit cycles, it is proved that the reachable set is totally determined for each switched convergent state. Finally, several examples and a real application are presented in order to illustrate the results.     

Stability analysis and stabilization control of multi-variable switched stochastic systems

In this paper, the mean square (MS) stability and exponential mean square (EMS) stability of multi-variable switched stochastic systems are investigated. Based on the concept of the average dwell-time and the ratio of the total time running on all unstable subsystems to the total time running on all stable subsystems, some sufficient conditions are given to ensure the MS stability and EMS stability of the switched stochastic systems involved. Further, for the switched stochastic control systems with all subsystems controllable or stabilizable, EMS stabilization controls and sufficient conditions on EMS stabilization are presented, and the convergent rates of the closed-loop systems are obtained.     

切换自治系统的动态输出反馈镇定

本文研究离散时间切换线性自治系统的输出反馈镇定问题. 在切换系统可观测的假设下, 设计具有多线性 时变增益的动态观测器, 实现有限时间状态估计. 在此基础上, 设计多路径动态输出反馈切换策略, 实现闭环系统指 数收敛.     

具有不确定性的非线性切换系统的约束预测控制

针对一类具有不确定性和变量约束的非线性切换系统, 提出了一种基于Lyapunov函数的预测控制方法, 其中状态约束分为两种情况: 1)要求状态变量在所有时刻都满足约束(称为硬约束); 2)允许状态在某些时刻超出约束(称为软约束). 主要思想是: 对切换系统的每一个子系统, 在输入和状态均受约束的情况下, 设计基于Lyapunov函数的有界控制器和预测控制器, 在两者之间适当切换, 得到初始稳定区域的描述并使得子闭环系统保持稳定. 对整个切换系统, 设计适当的切换律以保证: 1)在切换时刻, 闭环系统的状态处在切入系统的稳定区域内; 2)切入模块的Lyapunov函数是非增的, 从而可保证稳定性. 在状态变量的约束是软约束时, 对每一子模块首先设计一个控制策略, 尽快将状态控制到初始稳定区域, 然后再利用稳定区域内的控制律使系统稳定.     

Combined stabilizing strategies for switched linear systems

For a class of switched linear systems, we propose a switching strategy that combines time-driven switching with event-driven switching. This switching strategy not only makes the switched systems stable, but also reduces the switching frequency in contrast with the existing switching laws. In addition, the switching law is robust against (time-varying and nonlinear) system perturbations. We prove that, under this switching law, the perturbed systems are bounded for bounded perturbations, convergent for convergent perturbations, and exponentially convergent for exponentially convergent perturbations. For switched linear systems with measured outputs, we also develop an observer-based switching strategy which robustly stabilizes the perturbed systems.     

Conditions for stabilizability of linear switched systems

This paper investigates some conditions that can provide stabilizability for linear switched systems with polytopic uncertainties via their closed loop linear quadratic state feedback regulator. The closed loop switched systems can stabilize unstable open loop systems or stable open loop systems but in which there is no solution for a common Lyapunov matrix. For continuous time switched linear systems, we show that if there exists solution in an associated Riccati equation for the closed loop systems sharing one common Lyapunov matrix, the switched linear systems are stable. For the discrete time switched systems, we derive a Linear Matrix Inequality (LMI) to calculate a common Lyapunov matrix and solution for the stable closed loop feedback systems. These closed loop linear quadratic state feedback regulators guarantee the global asymptotical stability for any switched linear systems with any switching signal sequence.     

Robust admissibility of uncertain switched singular systems

This article investigates the robust admissibility of uncertain discrete-time switched singular systems. First, the admissibility is introduced, by using the switched Lyapunov function, for singular systems. Sufficient conditions for robust admissibility of uncertain switched singular systems are presented in strict linear matrix inequalities formulation. Robust admissibility condition designs for both state feedback and static output control feedback are then derived. Numerical examples are provided to illustrate our approach.     

一类受扰动脉冲切换系统鲁棒指数镇定

提出一类具有边界范数有界扰动的脉冲切换系统在任意切换条件下鲁棒指数镇定问题。应用Lyapunow直接法,导出这类受扰动脉冲切换系统指数稳定的充分条件并且给出线性时不变状态反馈控制律使该受扰动脉冲切换系统指数镇定,最后,给出数值示例说明所得到的结果是有效的。     

切换系统输入对状态稳定性的充分条件

研究了切换系统输入对状态的稳定性.在所有子系统都是输入对状态稳定的条件下, 利用各子系统的KY函数和K函数构造出切换系统所需的KY函数和X函数,从而给出了切换系 统输入对状态稳定的充分条件.对于一类常见的切换系统,计算出保证输入对状态稳定性的切 换停留时间的下界,所有结果都是构造性的.     

An algorithm for the robust exponential stabilization of a class of switched systems

In this paper, we consider continuous‐time switched systems whose subsystems are linear, or, more generally, homogeneous of degree one. For that class of systems, we present a control algorithm that under certain conditions generates switching signals that globally exponentially stabilizes the switched system, even in the case in which there are model uncertainties and/or measurement errors, provided that the bounds of that uncertainties and errors depend linearly on the norm of the state of the system and are small enough in a suitable sense. We also show that in the case in which the measurement errors and the model uncertainties are bounded, the algorithm globally exponentially stabilizes the system in a practical sense, with a final error which depends linearly on the bounds of both the model uncertainties and the measurement errors. In other words, the closed‐loop system is exponentially input‐to‐state‐stable if one considers the perturbations and output measurements bounds as inputs. For switched linear systems, under mild observability conditions, we design an observer whose state‐estimation drives the control algorithm to exponentially stabilize the system in absence of perturbations and to stabilize it in an ultimately bounded way when the perturbations and the output measurement errors are bounded. Finally, we illustrate the behavior of the algorithm by means of simulations. Copyright © 2014 John Wiley & Sons, Ltd.