共查询到18条相似文献,搜索用时 109 毫秒
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针对网络控制系统被控对象状态无法直接测量的情况,设计了状态观测器,给出了一种基于误差阈值的确定通信逻辑,应用于基于模型的网络控制系统中,提出了具有确定通信逻辑的网络控制系统结构,建立了系统模型,仿真数例表明加入确定通信逻辑后,在保持系统稳定的情况下,数据发送的次数明显减少,有效地减轻了网络负载。 相似文献
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基于带有随机时滞的多通信通道的网络控制系统镇定 总被引:2,自引:0,他引:2
基于带有随机时滞的多通信通道,建立了离散时间网络控制系统模型.利用缓存对丢包进行补偿,并设计了状态反馈控制器,使系统达到随机稳定.采用锥型补偿线性化(CCL)算法得到了控制器增益的全局最优解.最后通过倒立摆系统的仿真例子验证了所提出方法的可行性. 相似文献
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网络控制系统随机稳定性研究 总被引:7,自引:2,他引:7
研究了具有随机网络诱导时延及数据包丢失的网络控制系统随机稳定性问题. 本文用一个具有两个状态的马尔可夫链来描述数据通过网络传输时随机数据包丢失过程, 利用马尔可夫跳变线性系统理论, 将网络控制系统建模为一个具有两种运行模式的马尔可夫跳变线性系统, 给出了在状态反馈控制下网络控制系统随机稳定的线性矩阵不等式形式的充分条件, 最后用一个仿真示例验证了该方法的有效性. 相似文献
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池云 《电脑编程技巧与维护》2013,(16):107-109
针对一类随机时延网络控制系统,引入网络节点有效阀值的思想,并基于T—S模糊模型的概念,建立了具有随机时延和通信约束的网络控制系统模型,提出了一种网络控制系统鲁棒容错控制策略。基于线性矩阵不等式可行解,给出了控制器的参数化表达式。仿真结果,验证了所提方法的有效性。 相似文献
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This paper deals with the robust control problem for a class of uncertain nonlinear networked systems
with stochastic communication delays via sliding mode conception (SMC). A sequence of variables obeying Bernoulli
distribution are employed to model the randomly occurring communication delays which could be different for different
state variables. A discrete switching function that is different from those in the existing literature is first proposed. Then,
expressed as the feasibility of a linear matrix inequality (LMI) with an equality constraint, sufficient conditions are derived
in order to ensure the globally mean-square asymptotic stability of the system dynamics on the sliding surface. A discretetime
SMC controller is then synthesized to guarantee the discrete-time sliding mode reaching condition with the specified
sliding surface. Finally, a simulation example is given to show the effectiveness of the proposed method. 相似文献
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This paper considers the stochastic optimal control problem for networked control systems(NCSs)with control packet dropouts.The proportional plus up to the third-order derivative(PD3)compensation strategy is adopted to compensate for control packet dropouts at the actuator by using the past control packets stored in the buffer.Based on the strategy,a new NCS structure model with packet dropouts is provided,where the packet dropout is assumed to obey the Bernoulli random binary distribution.In terms of the given model,the stochastic optimal control law is proposed. Numerical examples illustrate the effectiveness of the results. 相似文献
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Lei Zhang Author Vitae 《Automatica》2006,42(6):953-958
This paper discusses the stabilization of a networked control system (NCS) in which sensors and actuators of a plant exchange information with a remote controller via a shared communication medium. Access to that medium is governed by a pair of periodic communication sequences. Under the model utilized here, the controller and plant handle communication disruptions by “ignoring” (in a sense to be made precise) sensors and actuators that are not actively communicating. This choice has the effect of significantly reducing the complexity of selecting control/communication policies. It is shown that, for discrete-time NCS, the reachability and observability of the plant can be preserved if the communication sequences are chosen properly. We propose a method for exponentially stabilizing a NCS by first identifying a pair of communication sequences that preserve reachability and observability and then designing an observer-based feedback controller based on those sequences. 相似文献
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This paper studies the problems of H-infinity performance optimization and controller design for continuoustime
NCSs with both sensor-to-controller and controller-to-actuator communication constraints (limited communication
channels). By taking the derivative character of network-induced delay into full consideration and defining new Lyapunov
functions, linear matrix inequalities (LMIs)-based H-infinity performance optimization and controller design are presented
for NCSs with limited communication channels. If there do not exist any constraints on the communication channels, the
proposed design methods are also applicable. The merit of the proposed methods lies in their less conservativeness, which is
achieved by avoiding the utilization of bounding inequalities for cross products of vectors. The simulation results illustrate
the merit and effectiveness of the proposed H-infinity controller design for NCSs with limited communication channels. 相似文献
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Hui Lu 《International journal of systems science》2016,47(10):2370-2381
A novel integrated design scheme of average dwell time scheduling strategy, dynamic bandwidth allocation policy and quantised control for a collection of networked control systems (NCSs) with time delay and communication constraints is proposed in this paper. A scheduling policy is presented to accommodate the limitation of communication capacity which depends on the convergence rate of closed-loop system and divergence rate of open-loop plant. Linear programming technique is adopted to dynamically allocate bit rate for each node and the strategy is used to make trade-offs between the network utilisation and the control performance which provides an effective way of optimising the quality of control (QoC) and the quality of service (QoS) for NCSs. Mid-tread uniform quantisers update the quantisation rules according to the assignment of the bit rate and convert the quantised state into a kind of input saturation with bounded disturbances. Taking into account the effect of dual scheduling strategy and quantisation, the NCSs are modelled as discrete-time switched systems with bounded disturbances. Furthermore, a scheduling and quantised feedback control co-design procedure is proposed for the simultaneous stabilisation of the collection of networked subsystems. Finally, a simulation example is given to illustrate the effectiveness of the proposed method. 相似文献
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Toivo Henningsson Author Vitae Erik Johannesson Author VitaeAuthor Vitae 《Automatica》2008,44(11):2890-2895
The standard approach in computer-controlled systems is to sample and control periodically. In certain applications, such as networked control systems or energy-constrained systems, it could be advantageous to instead use event-based control schemes. Aperiodic event-based control of first-order stochastic systems has been investigated in previous work. In any real implementation, however, it is necessary to have a well-defined minimum inter-event time. In this paper, we explore two such sporadic control schemes for first-order linear stochastic systems and compare the achievable performance to both periodic and aperiodic control. The results show that sporadic control can give better performance than periodic control in terms of both reduced process state variance and reduced control action frequency. 相似文献
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Error encoding algorithms for networked control systems 总被引:1,自引:0,他引:1
A networked control system is characterized by having a feedback loop closed through a local area network. This paper considers methods for scheduling the use of the network to guarantee both stability and controller performance. We propose and validate algorithms for choosing message identifiers for dynamically scheduled networked control systems. Two schemes for selecting priority levels are proposed: a fixed arbitrary grid and an auto-scaling grid. We prove that the system is uniformly ultimately bounded in the case of the fixed encoding scheme, and asymptotically stable with auto-scaling. An inverted pendulum is used to illustrate the encoding methods. 相似文献
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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. 相似文献