【作者】 李亚洁；

【导师】 李炜；

【作者基本信息】 兰州理工大学 ， 控制理论与控制工程， 2017， 博士

【摘要】 近年来,尽管在网络化控制系统（Networked Control Systems,NCS）的容错控制研究领域已取得了不少成果,但被动容错远多于主动容错,时间触发机制下孤立进行容错设计的结果远多于事件触发机制下进行容错与通讯协同设计的结果。随着NCS这一控制与通讯的集成产物对系统安全性和网络资源节约性要求的日益增高,NCS容错控制研究领域仍面临着许多新的问题,诸如:如何实现NCS主动容错中故障估计、故障调节与网络通讯间的协同设计,如何实现具有多目标约束的NCS鲁棒被动容错与网络通讯间的协同设计,又如何使设计结果具有较少的保守性以更好的平衡离散事件触发通讯机制（Discrete Event-triggered Communication Scheme,DETCS）中变传输周期与系统性能间的关系等等。着眼于上述问题,本文展开了如下工作:1)研究了具有执行器饱和约束的不确定线性和非线性NCS的鲁棒被动容错与网络通讯间的满意协同设计问题。建立了DETCS下涵盖执行器饱和约束、网络时延、事件触发通讯约束的线性和T-S模糊非线性NCS的不确定闭环故障模型。将α-稳定性的定义引申为容错系统的α-安全度,并提出了具有α-安全度的容错吸引域和具有α-安全度的容错收缩不变集的相关定义,用于处理具有执行器饱和约束的NCS容错控制问题。基于Lyapunov稳定性理论和改进的Jensen不等式,分别推证出了具有α-安全度、α-安全度和H_∞-性能、α-安全度和H_∞/H₂-性能的不确定闭环故障NCS的鲁棒被动容错与网络通讯间的满意协同设计方法。2)在非均匀传输周期下,研究了具有执行器饱和约束的不确定线性和非线性NCS的鲁棒被动容错与网络通讯间的满意协同设计问题。将DETCS下非均匀传输NCS的采样器与事件发生器虚拟为一个非均匀采样开关,进而基于非均匀采样系统的理论来研究非均匀传输问题。基于文中提出的新型数据发送区间的剖分方法,建立了非均匀传输下带执行器饱和约束的线性和T-S模糊非线性NCS的不确定闭环故障模型;基于非连续的Lyapunov稳定性理论、Wirtinger’s不等式和线性凸组合理论,分别推导出了具有α-安全度、α-安全度和H_∞-性能、α-安全度和H_∞/H₂-性能的不确定闭环故障NCS的鲁棒被动容错与网络通讯间的满意协同设计方法。由于该方法具有更少的保守性,因此更易提高容错与通讯间的协同设计满意度。3)在非均匀传输周期下,研究了具有执行器饱和约束的线性和非线性NCS的鲁棒主动容错与网络通讯间的满意协同设计问题。提出了将状态、故障估计与控制、调节置于智能传感器和控制器中分布实施的系统架构。基于等物理采样周期的时间触发观测器和虚拟变采样周期的事件触发控制器,建立了主动容错框架下线性和T-S模糊非线性NCS的闭环故障模型。基于Lyapunov稳定性理论和线性凸组合理论,首先在等物理采样周期下通过采用连续时间状态观测器提出了具有广义H_∞性能的状态和故障估计方法;进而又在非均匀传输周期下,通过采用动态输出反馈先后提出了闭环故障NCS分别具有α-稳定性、α-稳定性和广义H_∞-性能,α-稳定性和广义H_∞/H₂-性能的主动容错和网络通讯间的满意协同设计方法。4)对1)³)中的理论结果进行了有效性、相容性与保守性的研究,验证了结果的有效性,揭示了适用于NCS容错与网络通讯间协同设计的定性折中原则,并探寻出事件触发参数的量化选取依据。采用经典的算例,先验证了理论结果的正确性与有效性。进而通过大量的仿真实验,揭示出了容错控制与网络通讯间、及不同的系统性能间存在着相容相斥的折中类定性关系;进一步又深入探究了事件触发参数σ与数据发送率n_s间的关系,通过数据拟合得到了σ-n_s间的定量数学表达式,为在给定网络通讯资源约束下进行NCS容错与通讯的协同设计提供了σ选取的量化依据。5)搭建了具有执行器饱和约束的NCS被动容错及主动容错的实验平台,对文中提出的协同设计理论结果进行了实验研究。借助于工控行业的软件接口标准（OLE for Process Control,OPC）等通讯技术及先进控制实验室现有实验设备,基于校园局域网,搭建了DETCS下具有执行器饱和约束的NCS被动容错实验平台,基于3)中提出的估计与控制、调节的分步实施理念,搭建了DETCS下的主动容错控制实验平台,并对被动容错和主动容错中的协同设计方法进行工程可用性验证及分析研究,得到了与单机版仿真结果相一致的结论。更多还原

【Abstract】 In recent years,the fault-tolerant control research field of networked control system（NCS）has made outstanding progress,however,the case s of passive fault-tolerant control are more than the cases of passive fault-tolerant control,and the case s which study the fault-tolerant problem in isolation based on the time-triggered scheme are more than the cases which study the co-design between fault-tolerant and communication based on eventtriggered scheme.With the increasingly high requirements of system safety and network resource saving property for NCS which is as the integration of control and communication,there are still many new problems in NCS fault-tolerant control field,such as,how to realize the co-design between fault-tolerant estimation,fault-accommodation and network communication in active fault-tolerant control field of NCS,how to realize the co-design between robust fault-tolerant control and network communication in NCS with mult i-objective constraints,and how to make the design result with less conservativeness to balance the relationship between the non-uniform transmission period of discrete event-triggered communication scheme（DETCS）and system performance,and so on.Driven by these problems,the main researches of this thesis are as follows:1)Study the satisfactory co-design proble m between the robust passive fault-tolerant and network communication for unce rtain linear and nonlinear NCS with actuator saturation constraints.The uncertain closed-loop failure model was established for linear and nonlinear T-S fuzzy NCS based on DETCS and the model include excellent information,such as,actuator saturation constraint,network time-delay,event-triggered communication constraints and so on.The definition of α-stability was extended to α-safety for tolerant system,and the definitions of fault-tolerant attractive domain with α-safety and the fault-tolerant contractive invariant set were proposed to deal with the fault-tolerant control problem for NCS with actuator saturation constraint.Based on Lyapunov stable theory and the improved Jensen inequality,the satisfactory co-design methods between robust passive fault-tolerant and network communication were derived for uncertain closed-loop failure NCS with mult i-objective constraints,such as,α-safety,α-safety and H_∞-performance,α-safety and H_∞/ H₂-performance.2)Under the non-uniform trans mission pe riod,study the satisfactory co-design proble m between passive robust fault-tole rant and network communication for unce rtain linear and nonlinear N CS with actuator saturation.The sampler and event generator were hypothesized to be the non-unniform sampling-switch in non-uniform transmission NCS.Furthermore,the non-uniform transmission problem was studied based on the theory of non-uniform sample system.Based on the new subdivision method of data transmission interval,the uncertain closed-loop failure model was built dedicatedly for linear and nonlinear T-S fuzzy NCS with actuator saturation constraints under non-uniform transmission period.Based on the discontinuous lyapunov stable theory,Wirtinger’s inequality and linear convex combination theory,the satisfactory co-design methods between robust passive fault-tolerant and network communication were derived for uncertain closed-loop NCS with multi-objective constraints,such as,α-safety,α-safety and H_∞-performance,α-safety and H_∞/ H₂-performance.As the methods possess less conservativeness,it is easier to improve the co-design satisfaction between fault-tolerant and communication.3)Under the non-uniform trans mission pe riod,study the satisfactory co-design proble m between active fault-tole rant and network communication for linear and nonlinear NCS with actuator saturation constraint.The distributed implementation architecture was put forward to solve active fault-tolerant co-design problem.In the architecture,the estimation of state and fault,the control and accommodation are located in the smart sensor and controller respectively to be implemented in distributed way.Based on the time-triggered observer under the equal physical sampling period and the event-triggered controller under the virtual non-uniform sampling period,the closed-loop failure model was established for liner and nonlinear T-S fuzzy NCS.Based on Lyapunov stable theory and linear convex combination theory,firstly the generalized H_∞estimation method of state and failure was presented by adopting continuous time observer under equal physical sampling period.Furthermore,under the non-uniform transmission period,the satisfactory co-design methods between active fault-tolerant and network communication were presented for closed-loop failure NCS with a-stability,a-stability and H_∞-performance,a-stablity and the generalized H_∞/ H₂-performance by adopting output feedback control law.4)Study the effectiveness,compatibility and conservative ness of the theoretical results in 1)³)to ve rify the validity of results.Reveal the qualitative compromise principle which is suitable for the co-design between fault-tole rant and network communication,and explore the quantitative selection basis of event-trigge red parameter.The correctness and effectiveness of the theoretical results is verified by some classical examples.The qualitative relationships with repulsion compatibility were revealed for fault-tolerant control,network communication and different system performance by carrying out lots of simulation experiment.Furthermore,the relationship between event-triggered parameter σ and data transmission ratio n_s was explored deeply.The quantitative mathematical expression for σ-n_s was put forward through data fitting,so it provides the quantitative selection basis of σ for the NCS co-design between fault-tolerant and communication under the constraint of given network communication resource.5)Establis h the passive fault-tole rant and active fault-tolerant experime ntal platform for NCS with actuator saturation to do the expe rimental study of the co-design theory proposed in the paper.With the help of software interface standard of industrial sectors（OLE for Process Control,OPC）and the existing equipment of the Advanced Control Laboratory,the passive fault-tolerant control experimental platform was built based on the campus local network for NCS with actuator saturation constraint under DETCS.In terms of distributed implementation concept for estimation,control and accommodation,the related active fault-tolerant experimental platform was established under DETCS.The engineering usability verification and analysis were carried out for the co-design method of passive fault-tolerant and active fault-tolerant,and the results is consistent with the stand alone version simulation.更多还原