具有非线性扰动的广义系统的鲁棒H∞控制

研究具有非线性结构扰动广义系统的鲁棒H∞控制和鲁棒H∞保性能控制问题,该不确定性为时间和状态的函数.且满足Lipschitz条件.目的是分别设计系统的鲁棒H∞控制器和鲁棒H∞保性能控制器.应用线性矩阵不等式方法,分别给出了系统的鲁棒H∞控制器和鲁棒H∞保性能控制器存在的充分条件.当这些条件可解时,分别给出了鲁棒H∞控制器和鲁棒H∞保性能控制器的表达式.最后通过一个仿真算例说明了所给出方法的应用.     

具有连续增益故障离散系统保性能可靠控制

针对不确定离散线性系统，采用连续增益故障模型，提出了考虑执行器故障的保性能可靠控制问题。通过对具有执行器故障不确定离散线性系统的分析，利用LMI分别给出了保性能标准控制器、保性能可靠控制器存在的充分条件及设计方法。根据凸优化理论．最优保性能标准控制器和最优保性能可靠控制器的设计方法转化为一个线性凸优化算法。在仿真数例中，不仅验证所提出方法的可行性；而且比较了最优保性能标准控制与最优保性能可靠控制。通过比较可以看出，当发生故障时，最优保性能标准系统将失去原有的性能和稳定性；最优保性能可靠系统仍将保持原有的性能。     

一类不确定切换模糊时滞系统的保性能控制

针对一类存在时滞的不确定切换模糊系统,研究系统的保性能控制问题.利用平行分布补偿算法(PDC)给出保性能控制器的设计方法,利用单Lyapunov函数方法和多Lyapunov函数方法,给出不确定切换模糊时滞系统保性能控制器存在的充分条件和切换律设计.使得闭环系统对所有允许的不确定,在所设计的控制器和切换律下实现保性能控制.仿真结果表明方法的有效性.     

时滞扩散性复杂网络同步保性能控制

针对节点扩张的时滞复杂网络系统, 在节点扩张的条件下, 讨论此类系统的同步保性能控制问题. 首先采用自适应控制方法, 利用Lyapunov-Krasovskii稳定性理论,结合矩阵不等式的凸优化问题处理方法, 得出了时 滞复杂网络系统保性能控制器存在的充分条件; 当系统节点的扩张后, 在原有自适应控制器不能使系统同步稳定的条件下, 设计脉冲控制器, 利用牵制控制原理使系统达到稳定同步. 所设计的自适应动态反馈控制器在保证系统的渐近稳定条件下使系 统性能指标满足一定的要求. 最后给出一个数值仿真说明其有效性.     

不确定广义系统的最优保性能控制

该文讨论不确定广义系统的最优保性能控制问题.给出了不确定广义系统保性能控 制器的两种设计方法:一是代数Riccati方程方法,给出了参数化的控制器;另一个是线性矩阵 不等式方法,给出了在使性能函数上界最小的意义下,最优控制器的设计算法,用实例演示了 该方法的有效性.     

多时滞不确定系统的模糊保性能H∞控制

针对多时滞不确定系统,利用T-S模型进行建模,提出了模糊保性能H∞控制问题.基于Lyapunov稳定理论,得到一种通过模糊状态反馈实现的具有干扰抑制的保性能H∞控制.当被控对象存在多时滞和不确定性及外部干扰统计特性未知时,该模糊控制器能保证闭环系统稳定和一定的二次型性能指标上界,同时具有H∞下的干扰抑制作用.控制器的设计可通过转化为线性矩阵不等式的求解问题.数值仿真表明,该控制器具有所期望设计的性能.     

变采样网络控制系统的最优保性能控制

研究了一类不确定时延网络控制系统的最优保性能控制问题.针对线性时不变控制对象,控制器和控制对象采用时间-事件驱动,系统成为变采样网络控制系统,考虑在不确定时延小于或者等于一个变采样周期时,基于动态输出反馈对变采样网络控制系统进行建模,利用线性矩阵不等式研究了系统的保性能控制,并设计了保性能控制率和最优保性能控制率,最后给出实例表明在最优保性能控制率的控制下系统稳定.     

一类非线性时滞系统的保性能控制器设计

针对一类具有非线性控制输入的参数不确定时滞系统和给定的保性能指标,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,得到了非线性不确定时滞系统的保性能控制存在的充分条件.与现有结果相比,考虑的保性能控制器是非线性的,并且保性能控制器可由线性矩阵不等式的解给出.得到的保性能控制器不仅保证...     

不确定时滞系统的保性能控制

基于时滞系统的一个新的指数稳定性定理,考虑了时不变不确定时滞系统的保性能控制问题.利用一种新的分析技术,通过解两个Riccati不等式和一个线性矩阵不等式得一保性能控制器,该控制器可保证闭环系统指数稳定且使系统满足一定的性能指标.与一般的不确定时滞系统保性能控制不同,所得的性能指标的上界中含有参数,可通过调整参数值的大小来使性能指标达到最优.所得Riccati不等式中含有时滞,因此该判据是时滞相关的.数值算例证明了该方法的适用性.     

不确定时滞系统保性能弹性控制器的设计

研究了一类不确定时滞系统的保性能控制问题, 其不确定性不仅存在于系统矩阵, 而且存在于控制器的增益中. 在控制器增益摄动具有加法和乘法两种结构形式下, 讨论了系统的弹性保性能控制器设计问题, 给出了弹性保性能控制器存在的充分必要条件. 数值算例说明了设计的可行性和有效性.     

Robust guaranteed cost control of uncertain fuzzy systems under time-varying sampling

In practice, the system is often modeled as a continuous-time fuzzy system, while the control input is applied only at discrete instants. This system is called a sampled-data control system. In this paper, robust guaranteed cost control for uncertain sampled-data fuzzy systems is discussed. A guaranteed cost control where a quadratic cost function is bounded by a certain scalar, not only stabilizes a system but also considers a control performance. A typical sampled-data control is the zero-order input, which can be represented as a piecewise-continuous delay. Here we take a delay system approach to the sampled-data guaranteed cost control problem. The closed-loop system with a sampled-data state feedback controller becomes a system with time-varying delay. First, guaranteed cost control performance conditions for the closed-loop system are given in terms of linear matrix inequalities (LMIs). Such conditions are derived by using Leibniz–Newton formula and free weighting matrix method for fuzzy systems under the assumption that sampling time is not greater than some prescribed scalar. Then, a design method of robust guaranteed cost state feedback controller for uncertain sampled-data fuzzy systems is proposed. Examples are given to illustrate our robust sampled-data guaranteed cost control design.     

Minimax guaranteed cost control of uncertain non-linear systems

In this paper, a guaranteed cost control for non-linear uncertain systems is developed. The relationship between the idea of guaranteed cost control and dissipative feedback is first discussed which have been independently studied in the literature on robust control. It turns out that the two approaches are equivalent, and both presume the existence of a storage function (a Lyapunov function candidate) which guarantees the stability of the closed-loop system. The idea of guaranteed cost control is then applied to solve the robust control problem for non-linear systems with both drift vector field and input vector field uncertainties. Necessary and sufficient conditions are given for the solvability of this problem in terms of certain Hamilton-Jacobi Isaac's inequalities. The robustness properties of the controllers are also discussed. Finally, a passivity-based approach to the synthesis of guaranteed cost controllers is discussed.     

基于干扰观测器的高超音速飞行器鲁棒反步控制

针对高超音速飞行器严格反馈不确定非线性MIMO系统,提出一种基于干扰观测器的鲁棒反步控制方法。该方法采用超扭曲算法设计干扰观测器以估计系统复合干扰,观测误差有限时间收敛。设计非线性反步控制律,引入鲁棒项使得系统满足干扰到性能输出的L2增益不超过设定的正实数,满足耗散不等式,使闭环系统跟踪误差一致最终有界稳定。仿真结果表明,所设计的控制律可以有效抑制系统复合干扰的影响,设计方法可行。     

一类不确定模糊动态时滞系统保成本控制

针对一类不确定非线性动态时滞系统，利用模相T—S模型，通过状态反馈对保成本控制问题进行研究。应用线性矩阵不等式给出模糊闭环系统渐近稳定的充分条件，保证了所有允许的不确定闭环系统是稳定的，而且对于一个给定的二次型成本函数，舱保证闭环成本不超过某个界。仿真结果表明所提出的控制方法是有效的。     

Robust reliability method for non-fragile guaranteed cost control of parametric uncertain systems

The problem of non-fragile guaranteed cost control of uncertain systems is studied from a new point of view of reliability against uncertainties. An efficient robust reliability method for the analysis and design of non-fragile guaranteed cost controller of parametric uncertain systems is presented systematically. By the method, a robust reliability measure of an uncertain control system satisfying required robust performance can be obtained, and the robustness bounds of uncertain parameters such that the control cost of a system is guaranteed can be provided. The optimal non-fragile guaranteed cost controller obtained in the paper may possess optimal guaranteed cost performance satisfying the precondition that the system is robustly reliable with respect to uncertainties occurring in both the controlled plant and controller gain. The presented formulations are in the framework of linear matrix inequality and thus can be carried out conveniently. The presented method provides an essential basis for the tradeoff between reliability and control cost in controller design of uncertain systems. Two numerical examples are provided to demonstrate the efficiency and feasibility of the presented method. It is shown that the coordination and simultaneous realization of the system performance, control cost, and robust reliability in control design of uncertain systems are significant.     

Non-fragile robust optimal guaranteed cost control of uncertain 2-D discrete state-delayed systems

This paper is concerned with the problem of non-fragile robust optimal guaranteed cost control for a class of uncertain two-dimensional (2-D) discrete state-delayed systems described by the general model with norm-bounded uncertainties. Our attention is focused on the design of non-fragile state feedback controllers such that the resulting closed-loop system is asymptotically stable and the closed-loop cost function value is not more than a specified upper bound for all admissible parameter uncertainties and controller gain variations. A sufficient condition for the existence of such controllers is established under the linear matrix inequality framework. Moreover, a convex optimisation problem is proposed to select a non-fragile robust optimal guaranteed cost controller stabilising the 2-D discrete state-delayed system as well as achieving the least guaranteed cost for the resulting closed-loop system. The proposed method is compared with the previously reported criterion. Finally, illustrative examples are given to show the potential of the proposed technique.     

不确定非线性时滞系统的非脆弱保成本控制

研究了一类具有状态时滞的不确定非线性系统的非脆弱保成本控制问题。通过利用Lyapunov稳定性理论和线性矩阵不等式方法,设计非脆弱保成本控制律,使得闭环系统渐近稳定,并且系统的性能指标不超过某个确定的上界。通过求解一个具有线性矩阵不等式约束的凸优化问题来设计最优非脆弱保成本控制器,以使得闭环不确定系统的性能指标最小化。仿真结果验证了该控制算法的有效性。     

不确定时滞系统的指定衰减度保代价可靠控制

针对一类含有时变时滞的不确定参数线性系统,研究了在执行器发生故障情况下系统具有指定衰减度的保代价可靠控制器设计问题。系统中的参数不确定性满足广义匹配条件,时变时滞及其变化率有界,执行器失效采用增益故障模型。系统的性能函数是含有指数项和故障输入项的积分二次型函数。经过适当的状态变换,将原系统的指定衰减度保代价可靠控制问题转化为另一个等价系统的保代价可靠控制问题。根据Lyapunov稳定性理论,得到了系统存在指定衰减度保代价可靠控制器应满足的一个矩阵不等式,进一步将这个矩阵不等式转化为线性矩阵不等式（LMI）,并给出了系统的保代价表达式。利用论文方法设计的指定衰减度保代价可靠控制器能够使得时滞系统对于任意允许的不确定量以及执行器故障都保持鲁棒可靠指数稳定,并且使系统具有保代价的性能指标。     

Robust synergetic control design under inputs and states constraints

In this paper, a novel robust-constrained control methodology for discrete-time linear parameter-varying (DT-LPV) systems is proposed based on a synergetic control theory (SCT) approach. It is shown that in DT-LPV systems without uncertainty, and for any unmeasured bounded additive disturbance, the proposed controller accomplishes the goal of stabilising the system by asymptotically driving the error of the controlled variable to a bounded set containing the origin and then maintaining it there. Moreover, given an uncertain DT-LPV system jointly subject to unmeasured and constrained additive disturbances, and constraints in states, input commands and reference signals (set points), then invariant set theory is used to find an appropriate polyhedral robust invariant region in which the proposed control framework is guaranteed to robustly stabilise the closed-loop system. Furthermore, this is achieved even for the case of varying non-zero control set points in such uncertain DT-LPV systems. The controller is characterised to have a simple structure leading to an easy implementation, and a non-complex design process. The effectiveness of the proposed method and the implications of the controller design on feasibility and closed-loop performance are demonstrated through application examples on the temperature control on a continuous-stirred tank reactor plant, on the control of a real-coupled DC motor plant, and on an open-loop unstable system example.     

Quadratic guaranteed cost control for uncertain dissipative models: A Riccati equation approach

The problem of H₂ guaranteed cost control and dynamic output-feedback for linear uncertain systems with dissipative uncertainty is addressed. The problem of robust H₂ synthesis has been open for the last two decades. In this paper, a problem of H₂ quadratic guaranteed cost control is defined for uncertain systems affected by LTI quadratic dissipative model uncertainty. A necessary and sufficient condition of quadratic stabilizability via output-feedback is derived in terms of two coupled parameter-dependent Riccati equations. Then, a method is given to design controllers which minimize an upper bound for the worst-case H₂ norm of the uncertain system. It therefore assesses a guaranteed level of robust performance where in literature, only nominal performance is ensured in most cases. A reliable numerical iterative procedure based on Riccati solvers and one-dimensional convex parameter search is provided. With this uncertainty modelling and the developed numerical procedure, we hope to reduce the usual conservatism of quadratic designs.