具有执行器饱和的正线性系统的事件触发控制

尽管事件触发控制策略在提升通信效率方面效果显著, 但在实际运用过程中, 可能会因为触发次数的减少而导致系统稳定性下降. 针对这一问题, 本文提出了一种新的事件触发控制策略, 实现了执行器饱和正线性系统在通信效率和系统稳定性之间的平衡. 首先, 引入权重因子构建了一种线性加权事件触发机制, 并基于该机制和凸包技术设计了事件触发状态反馈饱和控制器; 其次, 利用线性余正Lyapunov函数方法, 在事件触发机制下分别建立了一般吸引域估计和最大吸引域估计下闭环系统正性和稳定性的充分条件. 这些条件可以退化为时间触发机制下的条件, 从而实现通信效率和系统性能之间的平衡; 再次, 给出了事件间隔时间的严格正下界, 从而避免了Zeno行为,即系统在有限时间内进行无限次触发; 最后, 通过一个仿真例子验证了所提出的事件触发控制策略的有效性和优越性.     

基于事件触发的执行器饱和NCS容错控制

针对具有网络时延和执行器部分故障的网络化控制系统,考虑系统模型可能具有的参数不确定性以及未知扰动,研究执行器饱和时的稳定性问题。对网络时延提出离散事件触发机制,执行器部分故障采用故障矩阵方式,饱和项采取线性凸包法,由此推证出了闭环系统模型。构造Lyapunov 泛函,得出闭环系统在吸引域内达到稳定的充分必要条件,由此得到相应控制器的设计方法。利用仿真证明上述对系统的处理确实可以使系统达到渐近稳定,而事件触发机制也确实可以减少数据量的传输。     

基于CNF的饱和切换系统的事件触发控制

针对一类具有执行器饱和的切换系统,提出一种基于组合非线性反馈控制(CNF)的事件触发控制方法,以达到在保证系统性能的同时减少网络带宽占用的目的.首先,为了降低系统资源成本,构造事件触发机制来判断是否对系统当前状态进行采样,设计组合非线性反馈控制来提高系统的暂态性能;然后,利用多Lyapunov函数方法得到饱和切换系统在驻留时间切换信号下渐近跟踪问题的充分条件,同时证明事件触发最小的时间间隔大于零,从而避免芝诺(Zeno)行为;最后,通过仿真实例验证所提出方法的有效性.     

含执行器故障的切换非线性系统的事件触发自适应模糊容错控制

本文研究在平均驻留时间约束下,一类含有执行器故障的切换非线性系统输出反馈自适应模糊事件触发容错控制问题.首先,建立了一个模态依赖的状态观测器估计不可测量状态.利用模糊逻辑系统来逼近未知项.其次,构建自适应模糊容错事件触发控制方案能够节省网络资源和数据传输.然后,通过构造多Lyapunov函数和平均驻留时间法,证明闭环系统所有状态半全局一致最终有界的同时排除了Zeno现象.最后,通过数值仿真验证该方法的有效性.     

含执行器故障的切换非线性系统的事件触发自适应模糊容错控制

本文研究在平均驻留时间约束下,一类含有执行器故障的切换非线性系统输出反馈自适应模糊事件触发容错控制问题.首先,建立了一个模态依赖的状态观测器估计不可测量状态.利用模糊逻辑系统来逼近未知项.其次,构建自适应模糊容错事件触发控制方案能够节省网络资源和数据传输.然后,通过构造多Lyapunov函数和平均驻留时间法,证明闭环系统所有状态半全局一致最终有界的同时排除了Zeno现象.最后,通过数值仿真验证该方法的有效性.     

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.     

基于动态事件触发机制的饱和2-D系统输出反馈H∞控制

针对一类由Roesser模型描述的饱和2-D系统,为了缓解网络数据传输压力,研究基于动态事件触发机制的输出反馈H_∞控制器设计问题.首先,构建此类不确定饱和2-D系统的数学模型;其次,提出一种动态事件触发机制决定当前信息能否传输到网络,以降低信号的更新频率;运用Lyapunov函数方法,通过引入非负标量mu,得到保证相应闭环系统满足一定H_∞性能指标的充分条件及输出反馈控制器的存在性判据;此外,利用锥补线性化算法,将输出反馈控制器的设计问题转化为线性矩阵不等式约束下的非线性最小化问题;最后,结合数值仿真验证基于动态事件触发机制的输出反馈控制方法的有效性和可行性.     

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.     

具有饱和执行器的时滞广义系统的鲁棒控制

利用李亚普诺夫方法研究了时滞广义系统、不确定广义系统和不确定时滞广义系统的鲁棒镇定问题.首先设计了时滞广义系统的具有饱和执行器的控制律,并给出其闭环系统渐近稳定的充分条件.对不确定项是范数有界的不确定广义系统,给出其控制器的设计方法和闭环系统渐近稳定的充分条件.在此基础上,进一步给出了不确定时滞广义线性系统的镇定条件.最后,给出了一个数值算例来说明方法的有效性.     

带有稀疏执行器故障的事件触发网络化系统容错控制

针对一类具有事件触发信息传输机制的网络化控制系统,对系统故障执行器个数进行稀疏约束,研究系统在有限个执行器失效情况下的指数稳定及控制器设计问题。将系统故障执行器个数的约束转化为对控制器增益矩阵行的势约束,利用混合整数方法来解决这类稀疏约束的容错控制问题。在此基础上,利用Lyapunov泛函方法,得出闭环系统在有限个执行器失效情况下系统呈指数稳定的充分条件以及具有行稀疏约束的控制器设计方法。最后,通过一个飞行控制系统的数值仿真实例验证所提控制方法的可行性和有效性。     

Event-triggered Control of Positive Switched Systems with Actuator Saturation and Time-delay

Machine Intelligence Research - This paper investigates the event-triggered control of positive switched systems with randomly occurring actuator saturation and time-delay, where the actuator...     

线性开关系统的饱和控制

利用开关系统切换的特点研究了线性开关系统的饱和控制问题,在较弱的条件下,得到了开关系统饱和镇定的结果,即构成开关系统的每个子系统可以是非稳定的,但假定由开关系统构成的某个凸组合系统是可稳的.借助于Lyapunov函数设计饱和控制器,基于凸组合系统的稳定性设计切换规律,引入设计参数满足控制器实现的条件,使开关系统局部渐近稳定.     

Design of Switched Linear Systems in the Presence of Actuator Saturation

For a group of linear systems, each under a saturated linear, not necessarily stabilizing, feedback law, we design a switching scheme such that the resulting switched system is locally asymptotically stable at the origin with a large domain of attraction. By expressing each saturated linear feedback in a convex hull of a group of auxiliary linear feedbacks, we formulate and solve the problem of designing such a switching scheme as a constrained optimization problem with the objective of maximizing an estimate of the domain of attraction. Simulation results indicate that the resulting domain of attraction extends well beyond the linear regions of the actuators.      

Dynamic Output Feedback Control for Systems Subject to Actuator Saturation via Event‐Triggered Scheme

In this paper, the event‐triggered dynamic output feedback control problem for linear systems with actuator saturation is investigated. Event‐triggered scheme only transmits the corresponding signal when the event‐triggered condition is violated. Due to its advantage of saving communication resources, it is utilized to design the dynamic output feedback controller. A criterion is established to guarantee the stability of the closed‐loop system by introducing an exponential term for the Lyapunov function, which corresponds to the exponential term in the event‐triggered condition. The explicit design of the coefficient matrices of the controller is presented. Furthermore, a lower bound of the inter‐event time is calculated to avoid Zeno behavior. An optimization algorithm is then formulated to maximize the estimation of the domain of attraction. Finally, a numerical example is given to illustrate the effectiveness of our methods and to show the trade‐off between the size of the domain of attraction and communication resources saving.     

Stabilization and H∞ Control of Nonlinear Switched Hamiltonian Systems Subject to Actuator Saturation

This paper investigates the stabilization and H_∞ control problem of nonlinear switched Hamiltonian systems (NSHSs) subject to actuator saturation (AS) under arbitrary switching paths. First, based on the saturating actuator property, an appropriate state feedback is designed under a realistic assumption for the stabilization of NSHSs with AS. Then, an H_∞ controller is designed for NSHSs subject to AS with external disturbances in order to attenuate the disturbances. Futhermore, the results obtained for NSHSs are applied to study the stabilization and H_∞ control of switched nonlinear systems with AS via the Hamiltonian realization method. Finally, simulation examples show the efficiency of the methods and results proposed in this paper.     

Output Feedback Stabilization of Linear Systems With Actuator Saturation

The note presents a method for designing an output feedback law that stabilizes a linear system subject to actuator saturation with a large domain of attraction. This method applies to general linear systems including strictly unstable ones. A nonlinear output feedback controller is first expressed in the form of a quasi-LPV system. Conditions under which the closed-loop system is locally asymptotically stable are then established in terms of the coefficient matrices of the controller. The design of the controller (coefficient matrices) that maximizes an estimate of the domain of attraction is then formulated and solved as an optimization problem with LMI constraints     

Stability Analysis and Antiwindup Design of Switched Linear Systems with Actuator Saturation

International Journal of Control, Automation and Systems - This paper investigates the stability analysis and anti-windup design problem for a class of switched linear systems with input saturation...     

Stability of Switched Positive Linear Systems with Actuator Saturation under Mode-dependent Average Dwell Time

The stability problem is investigated for switched positive linear systems (SPLS) with unstabilized subsystem and actuator saturation. By using Lyapunov functions method and mode-dependent average dwell time (MDADT) strategy, sufficient conditions of the stability for the considered systems are established. We also give an estimate of the attraction domain. The convex hull represent approach is used to deal with actuator saturation. Finally, two examples are carried out to show the validity of results, which is less conservative than the average dwell time (ADT) switching.

     

Tracking Control of Leader-follower Multi-agent Systems Subject to Actuator Saturation

This paper addresses the tracking problem of leaderfollower multi-agent systems subject to actuator saturation. A leader node or command generator is considered, which generates the desired tracking trajectory. To track such a leader, a new family of scheduled low-and-high-gain feedback controllers is designed for each follower, provided that the linear dynamic mode is asymptotically null controllable with bounded controls, and such control laws rely on the asymptotic property of a class of parametric algebraic Ricatti equations. We show that if the associated undirected graph of the system is connected, with the proposed control law, all the followers can track the leader eventually. A simulation example is finally given to illustrate the performance of the proposed control scheme.