Output tracking control of cascade switched nonlinear systems

The output tracking problem for cascade switched nonlinear systems is studied based on the average dwell time method in this paper. Sufficient conditions for this problem to be solvable are derived, where the zero dynamics is unstabilisable under an arbitrary switching. When the switching signal satisfies an average dwell time scheme, H_∞ output tracking is achieved by virtue of a designed switched integral controller. A numerical example is illustrated to show the effectiveness of the main result.     

任意相对阶下非线性切换系统的事件触发漏斗控制

针对一类具有任意相对阶且带有部分非输入到状态稳定逆动态的非线性切换系统, 提出一种动态事件触 发漏斗跟踪控制方案. 首先, 引入一个虚拟输出将任意相对阶的非线性切换系统转换为相对阶为一的非线性切换系 统. 其次, 设计各子系统的事件触发漏斗控制器和切换的动态事件触发机制, 解决候选事件触发漏斗控制器和子系 统之间的异步切换问题, 所提方案消除已有文献中为所有子系统设计共同控制器带来的保守性. 在一类具有平均驻 留时间切换信号的作用下, 保证切换闭环系统的所有信号都是有界的, 且跟踪误差一直在预设的漏斗内演化, 并排 除采样中的奇诺现象. 最后, 一个仿真例子验证方案的实用性和有效性.     

Finite-time output feedback control of uncertain switched systems via sliding mode design

The problem of sliding mode control (SMC) is investigated for a class of uncertain switched systems subject to unmeasurable state and assigned finite (possible short) time constraint. A key issue is how to ensure the finite-time boundedness (FTB) of system state during reaching phase and sliding motion phase. To this end, a state observer is constructed to estimate the unmeasured states. And then, a state estimate-based SMC law is designed such that the state trajectories can be driven onto the specified integral sliding surface during the assigned finite time interval. By means of partitioning strategy, the corresponding FTB over reaching phase and sliding motion phase are guaranteed and the sufficient conditions are derived via average dwell time technique. Finally, an illustrative example is given to illustrate the proposed method.     

Finite-time event-triggered extended dissipative control for discrete time switched linear systems

This paper considers the problem of finite-time event-triggered extended dissipative control for a class of discrete time switched linear systems. The proposed system is modeled as a discrete time switched linear system with an event-triggered control scheme. Under the event-triggered transmission schemes, we give some sufficient conditions to guarantee the finite-time extended dissipative performance of the closed-loop switched system in terms of linear matrix inequalities. Furthermore, the state feedback controller gains are proposed by solving a set of linear matrix inequalities. Finally, a numerical example is given to show the effectiveness of the proposed methods.     

Adaptive iterative learning control for switched nonlinear continuous-time systems

In this paper, an adaptive iterative learning control (ILC) method is proposed for switched nonlinear continuous-time systems with time-varying parametric uncertainties. First, an iterative learning controller is constructed with a state feedback term in the time domain and an adaptive learning term in the iteration domain. Then a switched nonlinear continuous-discrete two-dimensional (2D) system is built to describe the adaptive ILC system. Multiple 2D Lyapunov functions-based analysis ensures that the 2D system is exponentially stable, and the tracking error will converge to zero in the iteration domain. The design method of the iterative learning controller is obtained by solving a linear matrix inequality. Finally, the efficacy of the proposed controller is demonstrated by the simulation results.     

Event-triggered finite-time dynamic output feedback control for switched affine systems with asynchronous switching

This paper investigates the event-triggered finite-time dynamic output feedback control for switched affine systems (SASs) with asynchronous switching. A key point of the study is to set up a dynamic output feedback switched affine controller together with an event-triggered mechanism (ETM). By using an average dwell time (ADT) approach and resorting to a controller-mode-dependent Lyapunov functional, the finite-time stability (FTS) performance is achieve for the closed-loop SASs. The system dynamics under the proposed ETM are fully discussed during the synchronous and asynchronous switching intervals. The existence of the lower bound on interevent intervals is discussed emphatically, which excludes the occurrence of Zeno behavior. Finally, an application example of the DC-DC converter is given to show effectiveness of the acquired control algorithm.     

Asymptotic stabilization for switched affine systems with time delay: A novel dynamic event-triggered mechanism

This article concentrates on the asymptotic stabilization problem of switched affine systems (SASs) with unmeasurable states and time delay by constructing a novel dynamic event-triggered mechanism (ETM). Given the limited network transmission and the difficulties caused by affine terms in excluding the triggering Zeno behavior, we propose a novel dynamic ETM. It has been shown that the dynamic ETM not only has fewer data transfers than the existing ETM but also avoids Zeno behavior while maintaining asymptotic stability. Then, by constructing a set of dynamic output feedback switched affine controllers and switching laws, delicately incorporating Lyapunov–Krasovskii functionals, an asymptotic stabilization criterion is derived for the closed-loop SASs. The design methods of the controllers and switching laws are skillfully implemented by solving a set of linear matrix inequalities. Finally, an application example of the flyback DC–DC converter is offered to verify the proposed algorithm.     

Adaptive fuzzy output-feedback fault-tolerant tracking control of a class of uncertain nonlinear switched systems

ABSTRACT

This paper considers the output-feedback fault-tolerant tracking control problem for a class of uncertain nonlinear switched systems with nonlinear faults and strict-feedback form, where the faults which are nonaffine occur on the actuator. As a kind of specialised function approximating tool, fuzzy logic systems (FLSs), are employed to approximate the unknown smooth nonlinear functions. A switched fuzzy observer is designed to address the problem of unmeasurable states, filtered signals are used to address algebraic loop problem and the average dwell time (ADT) method is further utilised to prove the stability of the resulting closed-loop systems under a type of slowly switching signals. Based on the backstepping recursive design technique and Lyapunov function method, an adaptive fuzzy output-feedback control scheme is developed. The developed control method can ensure all the signals are semi-globally uniformly ultimately bounded (SGUUB) and the system output tracks the reference signal tightly even if unknown fault occurs. A simulation carried on an example demonstrates the validity of the obtained control scheme.     

Finite-time stability of nonlinear switched impulsive systems

In this article, the problem of finite-time stability (FTS) of nonlinear switched impulsive systems is first considered. A new concept of FTS is introduced and sufficient conditions for a switched impulsive system to be finite-time stable are presented by using switched Lyapunov functions. Some results of FTS of impulsive systems and switched systems can be obtained from this article as special cases, respectively. Two numerical examples are given to illustrate the effectiveness of the proposed results.     

切换非线性系统的输出反馈周期事件触发控制

本文针对一类在任意切换信号作用下的切换非线性系统, 研究了其输出反馈周期事件触发控制问题. 所考 虑的非线性系统采用非严格反馈形式且含有未知时变控制系数. 在本文中, 仅利用采样时刻的系统输出. 为了估计 系统的不可量测的状态, 基于采样的系统输出构造了降维状态观测器. 为了减少通信资源的利用, 提出了一种新的 输出反馈周期事件触发策略, 该策略包含仅利用事件触发时刻的信息构造的输出反馈事件触发控制器以及仅在采 样时刻间歇性监测的离散事件触发机制. 通过选取可容许的采样周期及合适的公共Lyapunov函数, 证明了闭环系统 在任意切换下全局渐近稳定. 最后, 通过将本文中所给出的控制方案应用到数值算例中验证了其有效性.     

Finite-time stabilisation of a class of switched nonlinear systems with state constraints

This paper investigates the finite-time stabilisation for a class of switched nonlinear systems with state constraints. Some power orders of the system are allowed to be ratios of positive even integers over odd integers. A Barrier Lyapunov function is introduced to guarantee that the state constraint is not violated at any time. Using the convex combination method and a recursive design approach, a state-dependent switching law and state feedback controllers of individual subsystems are constructed such that the closed-loop system is finite-time stable without violation of the state constraint. Two examples are provided to show the effectiveness of the proposed method.     

Robust H-infinity integral sliding mode control for a class of uncertain switched nonlinear systems

This paper develops a new method to deal with the robust H-infinity control problem for a class of uncertain switched nonlinear systems by using integral sliding mode control. A robust H-infinity integral sliding surface is constructed such that the sliding mode is robust stable with a prescribed disturbance attenuation level γ for a class of switching signals with average dwell time. Furthermore, variable structure controllers are designed to maintain the state of switched system on the sliding surface from the initial time. A numerical example is given to illustrate the effectiveness of the proposed method.     

Output tracking control of nonlinear switched cascade systems using a variable structure control method

This article is concerned with the output tracking control problem for a class of nonlinear switched cascade systems under some average dwell-time-based switching laws. Firstly, stabilisation problem of this class of switched systems is considered. Then, the result is extended to the output tracking control problem. Based on the variable structure control technique and the characteristic of the system, the variable structure controllers and the average dwell-time are designed. The effectiveness of the proposed design approach is illustrated with simulation results.     

High-order repetitive control for discrete-time linear switched systems

This paper is concerned with the design of a high-order repetitive control (RC) law for a class of discrete-time linear switched systems with repetition-varying reference trajectories. First, a high-order RC law, which embeds the characteristic of known variation of the reference trajectories, is proposed to the system, and a two-dimensional (2D) model is presented to describe the control and learning actions of the repetitive control system by using the lifting technique. By choosing appropriate multiple Lyapunov–Krasovskii functions, sufficient conditions for asymptotic stability of the 2D system are derived in the form of a set of linear matrix inequalities. Finally, an example is given to illustrate the effectiveness of the proposed results.     

一类脉冲随机系统的有限时间有界性分析与H∞控制

本文研究一类线性脉冲随机系统的有限时间有界性及H_∞控制问题.首先,利用Lyapunov函数和平均脉冲区间条件,建立了系统有限时间均方有界定理;其次,基于H_∞控制理论,获得了保证系统有限时间有界且满足一定的H_∞性能指标的判据;再次,针对有限时间H_∞控制问题,给出了状态反馈控制器存在的充分条件.最后,用一个数值例子表明了理论结果的有效性.     

Finite-time non-fragile filtering for nonlinear networked control systems via a mixed time/event-triggered transmission mechanism

This paper is aimed at investigating the problem of mixed time/event-triggered finite-time non-fragile filtering for nonlinear networked control systems with delay. First, a fuzzy nonlinear networked control system model is established by interval type-2 (IT2) Takagi-Sugeno (T-S) fuzzy model, the designed non-fragile filter resolves the filter parameter uncertainties and uses different membership functions from the IT2 T-S fuzzy model. Second, a novel mixed time/event-triggered transmission mechanism is proposed, which decreases the waste of network resources. Next, Bernoulli random variables are used to describe the cases of random switching mixed time/event-triggered transmission mechanism. Then, the error filtering system is designed by considering a Lyapunov function and a sufficient condition of finite-time boundedness. In addition, the existence conditions for the finite-time non-fragile filter are given by the linear matrix inequalities (LMIs). Finally, two simulation results are presented to prove the effectiveness of the obtained method.     

Event-triggered control for switched systems in the presence of actuator saturation

In this paper, the event-triggered stabilisation problem for a class of switched systems with actuator saturation is investigated. Based on multiple Lyapunov function method and the average dwell time approach, a sufficient condition for exponential stability of such systems under event-triggered state-feedback controller is derived. To avoid Zeno behaviour, it is shown that there exists a positive lower bound for any two consecutive inter-event instants. Finally, two examples are presented to illustrate the effectiveness of the proposed method.     

Sampled‐data output feedback stabilization for a class of switched stochastic nonlinear systems

This paper investigates a global sampled‐data output feedback stabilization problem for a class of switched stochastic nonlinear systems whose output and system mode are available only at the sampling instants. An observer is designed to estimate the unmeasurable state and thus a sampled‐data controller is constructed with the sampled estimated state. As a distinctive feature, a merging virtual switching signal is introduced to describe the asynchronous switching generated by detecting the system mode via a sampler. By choosing an appropriate piecewise Lyapunov function, it is proved that the proposed sampled‐data controller with allowable sampling period can stabilize the considered switched stochastic nonlinear systems under an average dwell‐time condition. Finally, two simulation results are presented to illustrate the effectiveness of the proposed method.     

具有随机网络攻击的切换信息物理系统的事件触发控制（英文）

本文研究了随机网络攻击下切换信息物理系统的事件触发控制问题.将信息物理系统描述为一种切换线性系统形式.引入事件触发机制来节省系统资源和减轻网络负载,当误差超过给定阈值时传感器中的采样数据才通过通信网络传输到控制器中.考虑在传感器与控制器的通信网络中受到两种不同特征的随机网络攻击.在网络攻击和所设计的事件触发控制器下,建立了切换随机信息物理系统模型.利用模态依赖平均驻留时间方法构建了相应的切换信号.在设计的事件触发控制器和模态依赖平均驻留时间切换信号下实现了系统的均方指数稳定性,并给出了控制器增益.最后,通过实例验证了所得理论结果的有效性.