基于网络QoS的网络化控制系统保性能控制

研究存在时延和丢包的非理想网络传输情况下的网络化控制系统的保性能控制问题,得到了在非理想网络传输情况下的网络化控制系统存在保性能控制律的充分条件,提出了基于网络服务质量(QoS)的网络化控制系统的保性能控制器的设计方法,该方法是一种能够兼顾系统控制性能和网络服务质量的综合性控制方法.通过仿真实例验证了该方法的有效性.     

具有时延和丢包的NCS H∞保性能容错控制*

针对存在时延和丢包的网络化控制系统,研究执行器或传感器失效时,系统受外部有限能量扰动影响的Hinf保性能容错控制问题。文中将丢包当作一种特殊时延,考虑综合时延的区间快变特性,采用状态反馈控制策略,通过构造适当的Lyapunov-Krasovskii泛函,推证出了闭环系统对执行器或传感器失效故障具有Hinf保性能容错能力的时滞依赖充分条件,并以求解LMIs的方式给出了最优控制器的设计方法。最后以一个仿真算例验证了文中所述方法的可行性和有效性。     

具有数据包丢失的网络控制系统主动容错控制

在保证稳定性的前提下,研究具有数据包丢失的网络控制系统主动容错控制问题.基于一类包含马尔可夫丢包过程的网络控制系统模型,考虑了执行器可能失效的情况.利用Lyapunov稳定性理论和线性矩阵不等式方法,获得了系统的保性能被动容错控制器.从控制性能的角度考虑,针对不同的执行器失效模式,得到了丢包网络环境下系统的主动客错控制器的设计方法.数值示例表明,该控制器设计方法是有效的.     

不确定系统的网络化保性能控制

本文针对控制网络中存在着随机传输时延和数据包丢失的现象,考虑了网络化控制系统的状态反馈保性能控制器设计问题.首先采用时滞相关方法并引入自由权矩阵,给出了基于矩阵不等式的网络化二次型保性能控制器存在的充分条件,然后基于该充分条件获得了基于线性矩阵不等式的控制器设计方法,相应的网络化保性能控制律可以通过求解线性矩阵不等式来构造,并采用锥互补线性化算法给出了网络化次优保性能控制器的设计方法.最后数值示例演示了所得控制器设计结果的应用方法和有效性,并通过仿真比较了传统保性能控制器和网络化保性能控制器在网络化控制系统中的控制性能.     

Quantized H ∞ fault-tolerant control for networked control systems

Quantized H_∞ fault-tolerant control for networked control systems (NCSs) with partial actuator fault with respect to actuators is concerned in this paper. Considering transmission delay, packet dropout and quantization, a synthesis model with partial actuator fault is established. The piecewise constant controller is adopted to model NCS with the transmission delay and packet dropout. Due to data transmitted in practical NCSs should be quantized before they are sent to the next network node, the logarithmic static and time-invariant quantizers at the sensor and controller sides are proposed in the paper. For the established model, an appropriate type of Lyapunov functions is provided to investigate the delay-dependent H_∞ control problem. According to an optimal problem, the controller that makes the system achieve the best performance is designed. Finally, an illustrative example is given to demonstrate the effectiveness of the proposed approach.     

一种少保守性的NCS 鲁棒H∞ 保性能容错控制

研究一类含有时变时延和丢包的网络化控制系统的鲁棒H∞保性能容错控制问题．基于一种状态多时延模型,推导出确保闭环系统在执行器或传感器发生失效故障时具有鲁棒H∞保性能的时滞依赖充分条件,并针对求解具有LMIs约束的凸优化问题,给出了最优鲁棒如保性能容错控制器的设计方法．由于新模型中考虑了时延下界,且证明过程引入了适当自由权矩阵变量,所得结果具有较少保守性．仿真实例验证了所提出方法的有效性．     

Real-time guaranteed cost control of MIMO networked control systems with packet disordering

This paper discusses guaranteed cost control for multi-input and multi-output (MIMO) networked control systems (NCSs) with multi-channel packet disordering. Considering the time-varying and bounded network transmission delay, packet dropout and packet disordering, a novel model of NCSs is proposed by introducing the concept of packet displacement. It is worthwhile mentioned that this model can fully describe the dynamic characteristic of network and always guarantee the newest control input executed by the plant, which makes that the plant can be controlled in real time. The resulting closed-loop systems are jump linear systems due to the newest signals executed subject to Markovian chains. A real-time controller is designed for uncertain and certain NCSs based on Markovian theory combined with linear matrix inequality (LMI) techniques such that the closed-loop cost function value is not more than a specified upper bound that varies according to Quality of Services (QOS). Finally, numerical examples are given to illustrate the effectiveness of the proposed method.     

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.     

网络控制系统的滑模多步预估控制

针对网络控制系统中出现的长时滞、网络诱导噪声和数据包丢失,提出了的滑模多步预估控制器的设计方法.首先对提出的控制器进行了描述,它利用滑模控制的强鲁棒性来克服网络诱导噪声,采用多步预估的办法来处理网络中的时滞和数据包丢失.进而对导出的闭环网络控制系统的稳定性进行了分析.最后对通过网络控制的直流电机,采用所提出的方法设计了控制器,仿真结果验证了方法的有效性.     

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.     

Time delay and packet dropout compensation for networked control systems: a linear estimation method

This article studies the problem of H _∞ controller design for networked control systems (NCSs) with time delay and packet dropout. A linear estimation-based time delay and packet dropout compensation method is proposed. The delay switching-based method is presented to deal with the variation of time delay, and H _∞ controller design is presented for NCSs with packet dropout compensation by using linear matrix inequality (LMI)-based method. Then the combined delay switching and parameter uncertainty-based method is presented to model the variation of time delay, and H _∞ controller design is also presented. The simulation results illustrate the effectiveness of the newly proposed linear estimation-based time delay and packet dropout compensation.     

时滞广义区间系统的弹性保性能控制

研究了一类时滞广义区间系统的弹性保性能控制问题.利用线性矩阵不等式处理方法,导出了系统弹性保性能控制器存在的条件,证明了该条件等价于一个线性矩阵不等式的可行性问题,并用该线性矩阵不等式的可行解给出了弹性保性能控制器的一个参数化表示.进一步,通过求解一个凸优化问题,给出了系统的最优弹性保性能控制器的设计方法.最后的数值例子说明了所给方法的有效性.     

基于T-S模型的非线性网络控制系统的量化保成本控制

研究一类非线性网络控制系统的量化保成本控制问题．首先在考虑量化因素的影响下,基于Ｔ-Ｓ模糊模型方法建立包含时延、丢包和量化信息的新的非线性网络控制系统模型;其次运用Ｌｙａｐｕｎｏｖ稳定性理论和并行分布式补偿（ＰＤＣ）方法给出系统稳定性条件,运用锥补方法和线性矩阵不等式（ＬＭＩ）技术求解量化保成本控制器．仿真结果和横向比较结果验证了该方法的有效性．     

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.     

基于主动变采样周期方法的网络控制系统的H∞控制器设计

This paper studies the problem of designing H∞ controllers for networked control systems (NCSs) with both network-induced time delay and packet dropout by using an active-varying sampling period method, where the sampling period switches in a finite set. A novel linear estimation-based method is proposed to compensate packet dropout, and H∞ controller design is also presented by using the multi-objective optimization methodology. The simulation results illustrate the effectiveness of the active-varying sampling period method and the linear estimation-based packet dropout compensation.     

Compensation for control packet dropout in networked control systems

With the integration of communication networks and distributed control in modern manufacturing and process industries, networked control systems (NCSs) are becoming increasingly important due to its simplicity, scalability, flexibility, and cost effectiveness. However, there are still significant technical barriers that limit the applications of NCS technologies. Two challenges are network-induced time delay and data packet dropout. Applying a real-time queuing protocol that we developed recently, we are able to limit the sum of the network-induced communication delay and the control computation delay within a control period. This one-period delay is further guaranteed by well designed compensation for control packet dropout. Then, this paper proposes to compensate for the control packet dropout at the actuator using past control signals. Three model-free strategies for control packet dropout compensation, namely, PD (proportional plus derivative), PD2 (proportional plus up to the second-order derivative), and PD3 (proportional plus up to the third-order derivative) are developed. They are suitable for a large number of NCSs without the need to tune the compensator parameters. The proposed dropout compensation schemes are demonstrated through numerical examples.     

基于主动变采样周期方法的网络控制系统的H∞控制器设计

利用主动变采样周期方法, 本文研究了具有时延及丢包的网络控制系统的 H∞ 控制器设计问题, 其中采样周期在一个有限集合内切换. 提出了一个新的线性估计方法以补偿丢包的负面影响, 并利用多目标优化方法设计系统的 H∞ 控制器. 仿真结果表明了主动变采样周期方法及基于线性估计的丢包补偿方法的有效性.     

Guaranteed cost control of distributed parameter networked control systems with time‐varying delay

Distributed parameter networked control systems mean distributed parameter systems are controlled through a network, where the control loops are closed. In this paper, the problem of guaranteed cost and state feedback controller design is investigated for a class of distributed parameter networked control systems. With the network factors, such as transmission delays, data packet dropouts considered, the distributed parameter networked control system is modeled as a linear closed‐loop system with time‐varying delay and uncertain parameters. By selecting an appropriate Lyapunov‐Krasovskii function and using linear matrix inequality (LMI) approach, the controller is designed to render the system stable and it can keep the cost function less than a certain upper value. In addition, numerical simulation is included to demonstrate the theoretical results.     

基于T-S模型的倒立摆最优保性能模糊控制

对一类具有范数有界参数不确定性T-S模糊模型系统,采用状态反馈的并行分布补偿器(PDC)结构,基于线性矩阵不等式处理方法,研究了其最优保性能模糊控制律的设计问题.导出了保性能模糊控制律存在的条件,通过求解一个凸优化问题给出了最优保性能模糊控制律的设计方法,并用此方法设计了倒立摆系统的最优保性能模糊控制器.仿真实验验证了该设计方法的有效性.     

网络控制系统的H∞状态反馈控制器设计

研究了对网络控制系统如何设计H∞状态反馈控制器.这些网络控制系统中存在不确定的网络时延和数据包丢失.当网络时延和连续丢包有界时,可以将系统建模为具有时变输入时滞的系统,利用Lyapunov-Krasovskii泛函,推导出网络控制系统渐近稳定的充分条件.将这些充分条件转化为带等式约束的LMIs,并对他们进行迭代求解,就可以构造H∞控制器.与现有结果相比,在推导稳定性条件时本文对交叉项采取了更紧的界定,并且在设计控制器时无需知道调节参数.因此,本文提出的方法具有更低的保守性.仿真结果说明了本方法的正确性和有效性.