Asynchronous switching output feedback control of discrete-time switched linear systems

In this paper, the problem of dynamic output-feedback control synthesis is addressed for discrete-time switched linear systems under asynchronous switching. The proposed hybrid controller consists of a standard dynamic output-feedback switching control law and an impulsive reset law induced by controller state jumps. Using the average dwell time technique incorporating with multiple quadratic Lyapunov functions, the switching control synthesis conditions for asymptotic stability with guaranteed weighted ?₂-gain performance are derived as a set of linear matrix inequalities (LMIs). The proposed hybrid synthesis scheme advances existing design methods for output-feedback asynchronous switching control of switched linear systems in two important aspects: LMI formulation of the synthesis problem; and arbitrary order of the controller state. A numerical example is used to illustrate the effectiveness and advantages of the proposed design technique.     

Design of two-layer switching rule for stabilization of switched linear systems with mismatched switching

A two-layer switching architecture and a two-layer switching rule for stabilization of switched linear control systems are proposed, under which the mismatched switching between switched systems and their candidate hybrid controllers can be allowed. In the low layer, a state-dependent switching rule with a dwell time constraint to exponentially stabilize switched linear systems is given; in the high layer, supervisory conditions on the mismatched switching frequency and the mismatched switching ratio are presented, under which the closed-loop switched system is still exponentially stable in case of the candidate controller switches delay with respect to the subsystems. Different from the traditional switching rule, the two-layer switching architecture and switching rule have robustness, which in some extend permit mismatched switching between switched subsystems and their candidate controllers.     

Exponential stability and robust H∞ control of a class of discrete-time switched non-linear systems with time-varying delays via T-S fuzzy model

This paper deals with stability and robust H_∞ control of discrete-time switched non-linear systems with time-varying delays. The T-S fuzzy models are utilised to represent each sub-non-linear system. Thus, with two level functions, namely, crisp switching functions and local fuzzy weighting functions, we introduce a discrete-time switched fuzzy systems, which inherently contain the features of the switched hybrid systems and T-S fuzzy systems. Piecewise fuzzy weighting-dependent Lyapunov–Krasovskii functionals (PFLKFs) and average dwell-time approach are utilised in this paper for the exponentially stability analysis and controller design, and with free fuzzy weighting matrix scheme, switching control laws are obtained such that H_∞ performance is satisfied. The conditions of stability and the control laws are given in the form of linear matrix inequalities (LMIs) that are numerically feasible. The state decay estimate is explicitly given. A numerical example and the control of delayed single link robot arm with uncertain part are given to demonstrate the efficiency of the proposed method.     

具有Neumann边界的分布参数切换系统的容错控制

本文研究了一类具有Neumann边界条件的分布参数切换系统的容错控制问题.当执行器失效或部分失效时,运用Lyapunov函数法和Green公式,获得了闭环切换系统混杂状态反馈容错控制器存在的充分条件.然后运用线性矩阵不等式将容错控制器设计问题转化为一组线性矩阵不等式求可行解的问题,因而可以借助MATLAB中线性矩阵不等式工具箱来完成.同时,运用Poincare不等式减少控制系统设计的保守性.最后通过数值算例,验证所提出设计方法的有效性.     

On singular hybrid switched and impulsive systems

In this work, the problem of stability analysis for a class of singular hybrid switched and impulsive system (HSIS) is addressed. Corresponding to each subsystem, a hybrid switched and impulsive controller is designed and then the exponential stability property of the proposed singular HSIS is discussed for linear and nonlinear cases. Because switched systems without impulses are a special case of HSISs, the results are also given to switched system with synchronous and asynchronous controllers. The obtained results apply to control singular systems, and the introduced theorems allow knowing how the control must be designed. Two numerical examples are given to show the effectiveness of the proposed approaches. At first, by using MATLAB^® software, the proposed method is applied to a class of physiological processes of endocrine disruptor diethylstilbestrol models to illustrate the effectiveness of the results obtained here for the linear case. Thereafter, another numerical example is provided to support the presented theoretical results for the nonlinear case.     

Almost output regulation of switched linear dynamics with switched exosignals

For systems with switched linear dynamics and affected by persistent switched exosignals, we propose a new hybrid control approach to achieve not only closed‐loop stability but also tracking and/or rejection of persistent references/disturbances generated by multiple exosystems, namely, output regulation. It is assumed that both controlled plant and exosystem are described by switched linear models. The proposed hybrid controller/output regulator is specified as a switching impulsive system, where the controller states will undergo impulsive jumps at each switching instant. Based on the average dwell time switching technique, it has been shown how to completely reduce the synthesis problem of the hybrid controller to a set of linear matrix equations and linear matrix inequalities. Both continuous‐time and discrete‐time cases are discussed. To demonstrate its usefulness, the proposed hybrid control method has been applied to solve the output regulation problem for a mechanical system. Copyright © 2017 John Wiley & Sons, Ltd.     

短时延多包传输网络控制系统的容错控制

研究了存在数据丢失的短时延多包传输网络控制系统在静态调度和动态调度下的控制器设计问题。把未能成功传输数据的传感器节点视为暂时失效,将网络控制系统建模为一类具有时变传感器“故障”的系统。在静态调度策略下,将系统建模为一类具有一定切换规则的周期系统,利用容错控制理论和周期系统理论得到系统稳定性判据;在动态调度策略下,将系统建模为一类具有有限子系统的自主切换系统,利用容错控制理论和切换系统理论给出了系统的稳定性条件。并利用控制器和观测器的协同设计方法给出了系统在静态调度和动态调度下的容错控制律和状态观测器设计方法。数值仿真算例证明了结论的可行性和有效性。     

Observer‐Based Reliable Control for Discrete‐Time Switched Linear Systems with Faulty Actuators

This paper deals with the issue of reliable control for discrete‐time switched linear systems with faulty actuators by utilizing a multiple Lyapunov functions method and estimate state‐dependent switching technique. A solvability condition for the reliable control problem is given in terms of matrix inequality with an extra matrix variable. This condition allows the reliable control problem for each individual subsystem to be unsolvable. For each subsystem of such a switched system, we design an observer and an observer‐based controller. A switching rule depending on the observer state is designed which, together with the controllers, can guarantee the stability of the closed‐loop switched system for all admissible actuator failures. The observers, controllers, and switching law are explicitly computed by solving linear matrix inequalities (LMIs). The proposed design method is illustrated by two numerical examples.     

Fault estimator design for a class of switched systems with time-varying delay

This article studies the problem of fault estimator design for switched time-delay systems with impulsive control. The delay signal is assumed to be uniformly bounded, differentiable and has a bounded derivative. The problem is first formulated in the framework of H _∞ filtering by incorporating a priori knowledge of the fault into the design procedure. A hybrid controller, composed of a fault estimator and an impulsive controller, is constructed. Some delay-dependent sufficient conditions are derived on the existence of the hybrid controller by using the multiple Lyapunov functional approach. In addition, based on the cone complementarity algorithm, the solutions to the parameter matrices are obtained by solving a set of linear matrix inequalities. Finally, a numerical example is given to illustrate the effectiveness of the proposed approach.     

Digital optimal reduced-order control of pulse-width-modulated switched linear systems

In this paper digital optimal control of pulse-width-modulated switched linear systems is considered. The equivalent discrete-time system and its deviation around a stationary solution plays an important role. An optimal linear discrete-time deviation controller is developed. The controller is chosen to be one-step-ahead predictive, which is a natural choice for control of digital pulse-modulated systems. The controller is optimal, i.e. a cost criterion is minimized. The theory is generally applicable and gives, in principle, a tool to design a digital optimal controller for an arbitrary pulse-width-modulated switched linear system. The theory is illustrated by examples from the field of switched electrical networks.     

切换系统的稳定性及镇定控制器设计

由稳定子系统构成的切换系统经无限次切换可能产生不稳定,本文利用李亚谱诺夫函 数法,给出了确保由微分方程和差分方程描述的切换系统渐近稳定的充分条件,在此基础上 给出了不受切换条件限制的,但能使切换系统渐近稳定的镇定控制器设计方法,该方法简单 且易实现,并以一个例子作了说明．     

一类线性切换系统的非脆弱控制器设计方法

研究一类线性切换系统的非脆弱控制器的设计问题。分别考虑当系统的控制器增益存在加性摄动和乘性摄动时,利用公共Lyapunov函数法给出切换闭环系统混杂状态反馈控制器存在的条件,并通过变量替换和Schur补引理将非脆弱控制器的设计问题转换为线性矩阵不等式（LMI）的求解问题。通过仿真证实所提方法的有效性。     

Control of uncertain and parameter-variant piecewise linear systems

This paper introduces a method for controller design of uncertain and parameter-variant piecewise linear systems. The idea is to specify a desired performance, which is represented by a nominal system. Around this nominal system a compact set of systems is obtained which will be robustly stable against switching among members of this set: such a set of systems is then called the stable switched set. The paper shows that obtaining the stable switched set is a signomial program. It is shown that upper bounds on signomial programs can be easily obtained, which are used to compute the stable switched set. A sufficient condition is given for the existence of a common state feedback controller that stabilizes a number of uncertain and parameter-variant linear systems on a stable switched set. The paper proposes a synthesis procedure in terms of a constrained convex optimization problem that places the uncertain and parameter-variant systems optimally close to the desired nominal system, using one common state feedback controller. An extension is shown for the case that there exists no common state feedback controller. The synthesis framework is then applied to a simple example to demonstrate the procedure. It is shown that real systems, like active suspension of a car, transform natural into uncertain and parameter-variant piecewise linear systems.     

短时延多包传输网络控制系统的稳定性分析

提出一种短时延多包传输网络控制系统的建模方法.把多包传输网络控制系统建模为具有一定切换规则的线性切换系统模型.利用切换系统理论和鲁棒稳定性理论，得到多包传输网络控制系统的渐近稳定性判据,并首次提出周期动态输出反馈镇定控制器的设计方法.最后通过数值算例证明文中结论的可行性和有效性.     

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.     

Bumpless transfer for switched linear systems

This article deals with bumpless transfer for discrete-time switched linear systems. A bumpless transfer controller that is activated at every switching time for reducing the transient behavior is presented. The bumpless transfer control design is based on the finite horizon solution of a linear quadratic optimization problem. Dwell time conditions for assessing asymptotic stability of the closed-loop switched system are provided.     

LMI‐based stability analysis of linear hybrid systems with application to switched control of a refrigeration process

We consider continuous‐time switched linear systems associated with linear state reset during mode switches, which are called linear hybrid systems and can be commonly found in switched control systems via bumpless transfer during controller switches. We use a multiple Lyapunov functions approach to develop constructive tools for stability analysis of linear hybrid systems. In particular, we derive a linear‐matrix‐inequalities based procedure to compute upper bounds of dwell time for uniform global exponential stability in linear hybrid systems, and we apply it to a refrigeration process that is regulated by several switched proportional‐integral controllers via bumpless transfer. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Disturbance management design for a holonic multiagent manufacturing system by using hybrid approach

This paper proposes a disturbance management methodology for an agent-based holonic manufacturing system by using hybrid control approach, with its application to a mobile manipulator system. Firstly, the architectures based on holarchy and agents are given. Then the framework of hybrid control strategy is outlined and the stability analysis for the closed-loop system is introduced. The major contribution of this work is the exploration for using hybrid control approach into disturbance management mechanism. The switched disturbance detector is presented and the identification algorithm is given. The hybrid controller is designed to reject the disturbance by switching between reactions against diagnosed symptoms. Finally, the case study onto the mobile manipulator hybrid system verifies the effectiveness and applicability of this design method. It validates the agility, efficiency, and retaining stability to system of the holonic multiagent concept for industrial or other application systems.     

Non-fragile hybrid guaranteed cost control for a class of uncertain switched linear systems

1 Introduction In recent years, the switched control systems have been attracting considerable attention in the control commu- nity [1～7]. Basically, a switched system belongs to a spe- cial class of hybrid systems, which consist of a family of continuous-time or discrete-time subsystems and a switch- ing law that specifies the switching between them. Such control systems appear in many applications, such as com- municatin networks, switching power converters and many other fields. On the oth…     

基于二维混合模型的最优重复控制方法

针对一类线性系统,提出一种基于连续／离散二维混合模型的最优重复控制设计新方法．通过独立地 考虑重复控制系统连续的控制行为与离散的学习行为,建立了重复控制系统的连续／离散二维混合模型,并将重复 控制器设计问题转化为一类连续／离散二维系统的镇定问题．在此基础上,应用最优控制原理,对给定的性能指标 泛函,获得了最优重复控制律．通过调节性能指标泛函中的相关参数,可以对控制和学习行为进行独立的调节．最 后,通过数值仿真验证了所提方法的有效性．