一类非线性系统的鲁棒H∞控制

研究一类可部分反馈线性化且具扰动三角结构的非线性参数不确定系统的鲁棒H∞控制问题,不确定参数属于已知紧集并以非线性形式进入系统.在输入到状态稳定的理论框架下,基于李雅谱诺夫函数和反演法构造出状态反馈控制器,使得闭环系统对所有允许的参数不确定性是内稳定的,且从扰动输入到输出有有界的L2-增益.控制器的设计不需解任何H am ilton-Jacob i方程,并给出仿真算例说明了该结论的可行性和有效性.     

具有iISS未建模动态的非线性系统的状态反馈调节

针对一类具有积分输入到状态稳定(Integral input-to-state stability, iISS)未建模动态的非线性系统, 本文研究了状态反馈调节问题. 利用反推技术和iISS的性质, 通过恰当地选取设计函数和参数修正律, 给出了一个状态反馈控制器的设计过程. 所设计的控制器保证了闭环系统所有信号的有界性, 并且状态可以渐近调节到零. 仿真例子验证了该控制方案的有效性.     

一类非线性系统的鲁棒H ∞控制

研究一类可部分反馈线性化且具扰动三角结构的非线性参数不确定系统的鲁棒H∞控制问题,不确定参数属于已知紧集并以非线性形式进入系统.在输入到状态稳定的理论框架下,基于李雅谱诺夫函数和反演法构造出状态反馈控制器,使得闭环系统对所有允许的参数不确定性是内稳定的,且从扰动输入到输出有有界的L\-2-增益.控制器的设计不需解任何Hamilton-Jacobi方程,并给出仿真算例说明了该结论的可行性和有效性.     

一类具有积分输入到状态稳定未建模动态的高阶非线性系统的状态反馈调节

本文研究了一类具有积分输入到状态稳定(iISS)未建模动态的高阶非线性系统的状态反馈调节问题.基于反推技术和iISS的性质,通过恰当地选取设计函数和参数修正律,给出了一个状态反馈控制器的设计过程.设计的控制器保证了闭环系统所有信号的有界性,并且状态渐近调节到零.仿真例子验证了该控制方案的有效性.     

具有状态时滞和控制时滞的不确定性非线性系统的鲁春控制

对于具有状态时滞和控制时滞的不确定性非线性系统，当其线性部分的不确定性满足范数有界条件而非线性部分的不确定性满足匹配条件时，本文研究其鲁棒镇定问题。在整体指标稳定的意义下，我们得到了上述这类系统由可线性状态反馈和反馈镇定的条件－－某个代数黎卡提不等式有解。并且只要得到黎卡提不等式的解，就可很方便地设计出对应的控制器。     

脉冲变时滞车辆纵向跟随系统的群指数稳定性与控制

针对具有脉冲扰动和变时滞的顾前车辆纵向跟随系统,在假设各孤立子系统指数稳定的前提下,分析了该系统的群指数稳定性与控制.首先利用向量Lyapunov函数法和数学归纳法给出确保该系统群指数稳定的充分条件;然后基于得到的稳定性条件,采用滑模变结构控制策略对脉冲变时滞车辆纵向跟随系统进行控制器设计;最后通过一个数值仿真算例验证了所得结论的正确性以及在实际中如何应用.     

一类不确定性广义非线性系统的鲁棒控制

考虑一类上有不确定性广义非线性系统Ｅｚ＝（Ａ＋ΔＡ）ｚ＋Ｂｖ＋ｆ（ｚ）的鲁棒控制问题,这里Ｅ是奇异的ｆ（ｚ）系统的非线性部分,在适当的假设下,得到了基于状态反馈作用的鲁棒控制存在的条件。     

具有有界摄动的非线性系统鲁棒控制

针对不确定性由增益有界的摄动函数表示的非线性系统,讨论了状态反馈鲁棒镇定问题,结果表明,如果所讨论的系统具有鲁棒最小相位特性,且其标称系统相对阶为1,则反馈控制可以通过构造满足本文引理条件的正定函数得到。     

不确定非线性系统自适应镇定的充要条件

研究了一类相当广泛的包含未知参数的非线性控制系统的自适应鲁棒控制问题,这类系统的标称系统包含一些非最小相位非线性系统和一些不存在相对阶的非线性系统．其未知定常参数是线性的．在一定假设条件下,对该类系统给出了存在自适应控制器的充要条件,并采用backstepping方法给出了控制器的设计步骤．所得主要结论没有用到增长性假设、最小相位假设和相对阶的假设．同时,还给出了不存在相对阶及非最小相位的非线性系统的例子,对于后者给出了控制器的设计过程．     

一类非线性系统镇定问题的分层控制方法

通过利用分层控制设计方法,研究了一类仿射非线性系统的镇定问题.为了镇定这类系统,分层方法构建了一个简单的抽象系统,然后根据抽象系统的控制律求得原始系统的控制律.最后,一个四维仿射非线性系统的仿真例子说明了这种方法的有效性.     

拒绝服务攻击下网络化非线性系统的采样数据控制

本文研究了在拒绝服务攻击下网络化非线性系统的采样数据输出反馈控制问题.首先,为了避免使用完整的状态信息,在存在拒绝服务攻击的情况下设计了一种新颖的切换观测器.其次,同时考虑两个采样周期和拒绝服务攻击的影响,建立了一个新的切换增广系统模型,包括系统本身和误差系统.利用该模型和分段Lyapunov-Krasovskii泛函方法推导出保证切换增广系统是指数稳定的充分条件.进一步,利用线性矩阵不等式的解给出了观测器和控制器增益的共同设计方案.最后,通过仿真验证所提出控制方法的有效性.     

Sliding mode control for a class of nonlinear discrete-time networked systems with multiple stochastic communication delays

In this article, a sliding mode control problem is studied for a class of uncertain nonlinear networked systems with multiple communication delays. A sequence of stochastic variables obeying Bernoulli distribution is applied in the system model to describe the randomly occurring communication delays. The discrete-time system considered is also subject to parameter uncertainties and state-dependent stochastic disturbances. A novel discrete switching function is proposed to facilitate the sliding mode controller design. The sufficient conditions are derived by means of the linear matrix inequality (LMI) approach. It is shown that the system dynamics in the specified sliding surface is robustly exponentially stable in the mean square if two LMIs with an equality constraint are feasible. A discrete-time SMC controller is designed that is capable of guaranteeing the discrete-time sliding-mode reaching condition of the specified sliding surface. Finally, a simulation example is given to show the effectiveness of the proposed method.     

具有均匀量化器的非线性网络控制系统的一致有界性

建立一种非线性连续被控对象、系统总时延小于一个采样周期的网络控制系统连续模型.通过线性化及离散化的方法将非线性系统转换一种离散化的模型.利用Lyapunov稳定性理论和线性矩阵不等式方法,设计控制方法使系统稳定.在系统包含均匀量化器的情况下,设计控制方法使系统一致有界.通过调节量化器的误差范围,可以将系统状态控制在一定的范围内.实际中,据此可设计相应的量化级别及编码长度等参数.通过仿真验证控制方法的有效性,并分析了量化误差对系统收敛性的影响.     

Robust nonlinear variable selective control for networked systems

This paper is concerned with the networked control of a class of uncertain nonlinear systems. In this way, Takagi–Sugeno (T-S) fuzzy modelling is used to extend the previously proposed variable selective control (VSC) methodology to nonlinear systems. This extension is based upon the decomposition of the nonlinear system to a set of fuzzy-blended locally linearised subsystems and further application of the VSC methodology to each subsystem. To increase the applicability of the T-S approach for uncertain nonlinear networked control systems, this study considers the asynchronous premise variables in the plant and the controller, and then introduces a robust stability analysis and control synthesis. The resulting optimal switching-fuzzy controller provides a minimum guaranteed cost on an H₂ performance index. Simulation studies on three nonlinear benchmark problems demonstrate the effectiveness of the proposed method.     

Robust stability analysis of networked systems with varying delays

This article is concerned with networked controlled systems (NCS) with uncertain, varying, bounded transmission delays and asynchronous discrete-time static control laws. It is first shown that the delay variation gives rise to a discrete-time uncertain NCS model; robust stability analysis is carried out via a linear matrix inequality approach which, when combined with a directed parameter search, yields an estimate of robust stability bounds against any variations of the maximum allowable delay (constrained within one sampling period) that the closed-loop system can tolerate. The derived bounds are compared with other techniques relying on the singular values of the perturbed NCS-model. The presented simulation results prove the efficacy of the proposed control scheme.     

Sampled‐data control of networked nonlinear systems with variable delays and drops

This paper investigates the stabilization problem of the nonlinear networked control systems (NCSs) with drops and variable delays. The NCS is modeled as a sampled‐data system. For such a sampled‐data NCS, the stability properties are studied for delay that can be both shorter and longer than one sampling period, respectively. The exponential stability conditions are derived in terms of the parameters of the plant and time delay. On the other hand, a model‐based control scheme based on an approximate discrete‐time model of the plant is presented to guarantee the stability of the closed‐loop system subject to variable time delays and packet losses. The performance of the proposed control schemes are examined through numerical simulations of an automated rendezvous and docking of spacecraft system. Moreover, the simulations show that by employing the model‐based controller, a higher closed‐loop control performance can be achieved. Copyright © 2013 John Wiley & Sons, Ltd.     

带有随机时延的非线性网络控制系统的输出反馈镇定

考虑了一类非线性网络控制系统的输出反馈镇定问题.通过齐次马尔可夫链来描述采样器-控制器和控制器.执行器的时延,将网络控制系统建模为带跳非线性系统.利用Lyapunov方法和线性矩阵小等式技巧,得到了闭环系统随机稳定的充分条件,并给出了镇定控制器的设计方法.     

Sampled‐data control of nonlinear networked systems with time‐delay and quantization

In this paper, the stabilization problem of a class of nonlinear networked systems with time‐delay and quantization through sampled‐data control is investigated. With sampled‐data control, sufficient conditions to guarantee the trivial solution of the nonlinear networked system to be asymptotically stable without any quantization or with uniform quantization are derived. Finally, an example of a continuous‐time nonlinear system controlled through a digital controller and a communication channel is given to illustrate the effectiveness of the proposed control methods. Copyright © 2015 John Wiley & Sons, Ltd.     

自适应事件触发网络化非线性系统滤波器设计

本文针对网络化非线性控制系统设计了基于自适应事件触发方案满足H∞性能的模糊滤波器.第一,提出新的自适应事件触发方案来决定数据包是否需要传输到通信网络中,从而提高网络资源利用率;第二,运用模糊线积分的方法,构建模糊李雅普诺夫泛函,避免求解隶属函数的时间微分;第三,利用Wirtinger不等式及倒凸引理结合的技术,得到滤波...