Guaranteed cost control for networked control systems

The guaranteed cost control problem for networked control systems (NCSs) is addressed under conmmnication constraints and varying sampling rate. First of all, a simple inFormation-scheduling scheme is presented to describe the scheduling approach of system signals in NCSs. Then, based on such a scheme and given sampling method, the design procedure in dynarmic output feedback manner is also derived which renders the closed loop system to be asymptotically stable and guarantees an upper bound of the LQ pefformance cost function.     

Lurie网络化控制系统的保性能控制

以不确定Lurie系统作为被控对象,研究其在网络环境下的保性能控制问题.在同时考虑随机网络诱导时延和数据丢包的情况下,建立不确定Lurie网络化控制系统模型;利用Lyapunov方法分别给出了存在结构不确定性和范数有界的不确定性时,Lurie网络化控制系统保性能控制器的设计方法.所得结果是以线性矩阵不等式的形式给出的,便于数值求解.最后以数值实例说明了所提出方法的可行性和有效性.     

Guaranteed control concept for uncertain objects

Quite many engineering problems, problems from ecology, medicine, and social sciences are characterized by the presence of factors bringing uncertainty into the corresponding control systems. Additional difficulties for control action construction arise in the case when the objects are described by nonlinear high-order evolutionary equations. An important subset of these objects consists of the object with interval parametric uncertainty with a given control objective and with a given a given termination time of the transient process. For this objects, one of the possible ways of control action synthesis is the application of the guaranteed control concept. We propose the method of control synthesis for one class of nonlinear uncertain objects with using their robust models having linear structure and the parameters, depending on their state.     

具有数据包丢失的网络控制系统保性能控制

本文研究了一类具有数据包丢失的网络控制系统(NCSs)的建模和保性能控制问题.通过用两个马尔可夫链分别来描述前向通道和反馈通道的丢包过程,将闭环网络控制系统建模成具有两个模式的马尔可夫随机切换系统.基于线性矩阵不等式技术和李亚普诺夫方法得到了闭环系统随机稳定的充分条件,并给出了状态反馈保性能控制器的设计方法.最后通过数值算例验证本文结果的有效性.     

Guaranteed cost observer-based control of uncertain time-lag systems

This paper investigates the design of robust observer-based controllers for a class of uncertain linear time-lag systems. The uncertainties are assumed to be norm-bounded. We extend the previous results on quadratic-cost control to the case of observer-based control for uncertain systems with unknown state and input time-lags. By introducing an appropriate definition of quadratic stability for uncertain time-lag systems, it is shown that observer-based controllers can be constructed via solutions of linear-matrix inequalities. A simulation example is given to illustrate the theoretical developments.     

时滞复杂动态网络的保性能控制

针对具有时滞的复杂网络,研究了此类系统的保性能控制问题。利用Lyapunov稳定性定理和线性矩阵不等式工具,得到了时滞复杂网络保性能控制存在的充分条件。设计的具有增益摄动的状态反馈控制器,既可以保证系统渐近稳定,又可使系统的性能指标满足一定的要求,最后通过数值算例验证了设计方法的可行性。     

不确定时延网络控制系统的保性能控制

在工程实际网络控制系统中,不仅要求系统能够保持稳定,还要系统具有一定的性能指标,采用状态反馈控制是一种非常有效的控制方式。针对一类线性不确定时延网络控制系统,研究了在有记忆状态反馈控制器下的保性能控制问题。利用Lyapunov函数和线性矩阵不等式的方法,给出了网络控制系统保性能控制律存在的条件和相应的状态反馈控制器的设计方法。最后,通过Matlab数值仿真算例验证了该方法的有效性和正确性。     

具有传感器故障的网络控制系统保性能可靠控制

基于存在时延和丢包的网络传输环境.针对具有参数不确定性的网络化控制系统,研究了其在传感器故障条件下的保性能可靠控制问题.根据Lyapunov稳定性理论和线性矩阵不等式(LMIs)方法,推导出使闭环网络控制系统在传感器故障条件下渐近稳定且保证综合性能指标满足要求的充分条件,并利用LMIs提出了保性能可靠控制率的设计方法.该控制算法在提高网络化控制系统可靠性的同时有利于系统综合体性能的优化.数值仿真验证了该方法的可行性和有效性.     

数据包丢失网络控制系统的保成本控制

针对同时具有不确定短时延及数据包丢失的网络控制系统,引入丢包补偿器补偿丢包对系统的影响,当发生数据包丢失时,控制器采用丢包补偿器产生的预估状态代替系统的真实状态计算控制量。同时考虑不确定短时延的影响,将网络控制系统建模为一类具有参数不确定的离散切换系统．利用线性矩阵不等式(linear matrix inequality,简称LMI)方法给出了系统的保成本控制器和丢包补偿器的协同设计方法,仿真结果表明所提出的方法是有效的。     

Guaranteed cost repetitive control for uncertain discrete-time systems

This paper considers the problem of guaranteed cost repetitive control for uncertain discrete-time systems. The uncertainty in the system is assumed to be norm-bounded and time-varying. The objective is to develop a novel design method for the repetitive control systems by introducing a robust output feedback controller so that the closed-loop system is quadratically stable and a certain bound of performance index is guaranteed for all admissible uncertainties. Necessary and sufficient conditions for the existence of such controllers are derived in terms of linear matrix inequality (LMI). A suboptimal guaranteed cost controller is obtained by solving an optimization problem with LMI constraints. Finally, a simulation example is provided to illustrate the validity of the proposed method.     

Guaranteed cost control for saturated uncertain linear systems

In this paper, we discuss the problem of guaranteed cost control for uncertain linear systems subject to actuator saturation. Based on the quadratic and non-quadratic Lyapunov functions, sufficient conditions for the robust stability and performance are derived. Moreover, all the conditions can be expressed as linear matrix inequalities （LMIs） or bilinear matrix inequalities （BMIs） in terms of the feedback gain. Thus, the static controller can be effectively synthesized via convex optimization. A numerical example illustrates the effectiveness of the method.     

具有随机长时延的网络控制系统保性能控制

本文研究了一类具有随机长时延离散时间网络控制系统(NCSs)的建模和保性能控制问题.用两个马尔可夫链分别来描述反馈通道和前向通道的网络诱导时延,基于采用现有最新数据的原则,将闭环NCS建模成一个与当前时刻和过去时刻网络诱导时延有关的马尔可夫随机时滞系统.应用线性矩阵不等式技术和李亚普诺夫方法得到了闭环NCS随机稳定且具有二次性能指标上界的充分条件,并给出了状态反馈保性能控制器的设计方法.最后,通过数值算例验证了本文方法的有效性.     

Guaranteed cost control of systems with norm bounded uncertainties

Feedback controller design based on an imprecisely known plant model may cause performance degradation and even instability of the closed-loop system. It is therefore important to design robust controllers using a priori information on the model uncertainties. The method presented in this paper considers uncertainties satisfying bounding constraints, and ensures closed-loop stability as well as satisfactory performances characterized by a quadratic cost functional that remains bounded in the presence of uncertainties of the above class.     

不确定奇异时滞系统的保性能控制

利用线性矩阵不等式方法,讨论不确定性奇异时滞系统的保性能控制问题,给出了问题可解的一个充分条件和保性能鲁棒控制器的设计,以及相应的可保性能指标.最后举例说明了所提出方法的正确性.     

Guaranteed cost control of uncertain discrete systems with delays

In this paper, we address the problems of robust performance analysis and control synthesis for a class of discrete-time systems with parameter uncertainty and unknown state-delay. The parameter uncertainty is real time-varying normbounded and the state-delay is a constant within a prescribed interval. For the robust performance analysis problem, we adopt an appropriate notion of robust stability for discrete-time uncertain time-delay systems and show that this notion guarantees an upper bound on a linear quadratic cost function. For the control synthesis problem, we show that a robust state-feedback controller can be constructed to render the closed-loop system robustly stable while guaranteeing a prescribed level of performance. The developed results are expressed in terms of algebraic matrix inequalities. A numerical example is presented to illustrate the theory.     

不确定时延输出反馈网络化系统保性能控制

研究了一类具有不确定时延的动态输出反馈网络控制系统的保性能控制问题．针对小于等于一个采样周期的不确定时延,利用Lyapunov理论和线性矩阵不等式方法,推导出了动态输出反馈网络控制系统保性能控制律存在的条件,给出了动态输出反馈保性能控制律设计方法．利用LMI工具箱中的目标函数最小化工具,可以求得该类系统优化的保性能控制律参数和优化的性能指标,从而获得该系统的保性能控制律．给出的仿真算例说明了设计方法是有效的所得结果是可行的．     

Guaranteed cost control for multi-inventory systems with uncertain demand

In this paper we consider the problem of controlling a multi-inventory system in the presence of uncertain demand. The demand is unknown but bounded in an assigned compact set. The control input is assumed to be also constrained in a compact set. We consider an integral cost function of the buffer levels and we face the problem of minimizing the worst-case cost. We show that the optimal cost of a suitable auxiliary problem with no uncertainties is always an upper bound for the original problem. In the special case of minimum-time control, this upper bound is tight, namely its optimal cost is equal to the worst-case cost for the original system. Furthermore, the result is constructive, since the optimal control law can be explicitly computed.     

Guaranteed cost control of tracking problems with large plant uncertainty

A linear tracking problem with large plant uncertainty is studied. The guaranteed cost method is applied to design the controller so that the system responses follow the reference model. A modified Riccati matrix equation is obtained. From the numerical simulation of a second-order system, it is shown that the present method provides good performance in both tracking property and sensitivity immunity.     

Guaranteed cost control of synchronisation for uncertain complex delayed networks

In this article, the synchronisation for a class of complex delayed dynamical networks with uncertain inner coupling configuration is investigated under the quadratic guaranteed cost control. The coupling delay and nodes delay are considered in the networks. Based on Lyapunov–Krasovskii stability theory, sufficient conditions for the existence of the optimal guaranteed cost control laws are given in terms of linear matrix inequalities. Under these sufficient conditions, the networks are globally asymptotically synchronous, and the optimal upper bound is also guaranteed. Numerical examples are given to illustrate the effectiveness of the proposed methods.     

Guaranteed cost synchronous control of time-varying delay cellular neural networks

This paper deals with the synchronization of time-varying delay cellular neural networks. Based on the Lyapunov stability analysis and the zoned discussion and maximax synthesis (ZDMS) method, the quadratic matrix inequality (QMI) criterion for the guaranteed cost synchronous controller is designed to synchronize the given chaotic systems. For the convenience to solve, using a generalized result of Schur complement, the criterion in the form of QMI is turned into the linear matrix inequality (LMI) form, which can be used efficiently via existing numerical convex optimization algorithms such as the interior-point algorithms for solving LMIs. The minimization of the guaranteed cost is further studied, and the corresponding LMI criterion for getting the controller is given. Finally, numerical examples are given to show the effectiveness of proposed guaranteed cost synchronous control and its corresponding minimization problem.