Optimal bandwidth scheduling of networked control systems （NCSs） in accordance with jitter

INTRODUCTION Compared with point-to-point control, the major advantages of networked control (NC) include flexi-bility of operation, integrated diagnostics, quick and easy maintenance and monitoring, small wiring volume, low cost. There are also many disadvantages due to the limited bandwidth resources shared by all nodes. Two major consequences are the net-work-induced delay and the jitter, the transmission fluctuations of successive instances of a data, both of which can degrade the dy…     

网络化控制系统的转换控制算法

对于延迟大于一个采样周期的网络化控制系统,本文提出了一种转换控制算法,根据延迟落入的不同概率区间选取对应的控制器,进行转换控制,仿真结果验证了算法的有效性。     

丢包网络控制系统的稳定陛分析与控制器设计

针对网络控制系统的数据丢包问题,提出将网络控制系统中的丢包问题等价地转换为k采样周期网络控制问题,进而通过变换将k采样周期的网络控制系统等价转化为变时延网络控制系统。在此基础上,将李雅普诺夫稳定性理论与线性矩阵不等式方法相结合,给出这种变时延网络控制系统的稳定性判据和控制器设计方法。最后通过仿真结果验证了文中方法的有效性。     

一类不确定时滞网络控制系统的鲁棒控制

本文研究了一类具有状态时滞且模型中具有时变参数不确定性网络控制系统的鲁棒控制问题,基于Lya-punov稳定性理论,设计了系统的状态反馈控制器,并以线性矩阵不等式形式给出了系统的渐进稳定的充分条件,可以通过Matlab工具十分方便的求解。     

网络化控制在实验教学中的应用

网络化控制作为当前的一个研究热点，备受各方面关注。将网络化控制引入到具体的实验教学中，具有重要的意义。文章以网络化远程温度控制为例，对网络化控制在实验教学中的应用进行了具体探讨和实践。     

一类不确定时延和丢包的网络控制系统指数稳定性

针对控制器具有加法摄动和乘法摄动的一类不确定时延和丢包的网络控制系统,研究了指数稳定性问题。考虑了在不大于一个采样周期的情况下,对于给定的数据包丢失率,网络控制系统被建模为具有两个事件速率约束的异步动态系统,利用异步动态系统理论给出了网络控制系统指数稳定的充分条件。最后用仿真例子表明所给出的结果是有效的。     

基于OPC技术的网络控制系统仿真平台设计

网络控制系统(NCS)是一种新型计算机控制系统,通过工业网络实现控制单元之间的数据交换,但这也给控制系统带来了时延等问题。开发了一种基于Matlab和OPC技术,以校园局域网为媒介的虚拟NCS实验平台,利用西门子S7-300PLC作为实验平台的服务器,用Matlab OPC Toolbox工具箱提供的OPC技术实现OPC服务器与客户端的网络通信,实现了对象模型和控制器在两台计算机的分离,从而获得网络化控制系统仿真平台,为高级控制算法的研究和验证提供了良好的实验平台。     

Exponential stability for networked control systems based on the model of nonlinear discrete-time system with time-varying delay

1.IntroductionAsthecomplexityofmoderncontrolsystems,itsdimensionbecomesmoreandmorevast.Actuators,sensorsandcontrollersinsystemsareusuallydistributed.Theclose-loopfeedbackcontrolsystemscanbeestablishedviaconnectingthesenodeswithcommunicationnetwork.Thesesystemsareoftencallednetworkedcontrolsystems(NCSs).TheNCSsbasedonfieldbusnetwork,suchasCANbus,havebeenwidelyusedinvariousindustrialareasinrecentyears.Therearemanynewissueswhenusingnewsystems.Thefirstissueisthenetwork-induceddelay(sensor-to-…     

Predictive control of a class of bilinear systems based on global off-line models

INTRODUCTION Bilinear systems are a kind of important nonlinear systems with relatively simple structure, and many industrial processes can be described as a bilinear system. Thus research on the control of this kind of systems is very important. On the other hand, model predictive control (MPC) (Clarke et al., 1987) has been widely used in industrial applications and many predictive control methods focusing on bilinear systems are emerging (Bloemen et al., 2001; Fontes et al., 2004; He…     

利用一种新LDPC码的编码OFDM系统性能分析

提出了一种新的构造LDPC码的方法, 并把用该方法产生的LDPC码应用到编码正交频分复用(OFDM)系统中进行了研究. 该方法拓展了单位阵移位构造的LDPC码, 它利用简单的不等式可确保在置换单位阵构造中不会产生Tanner图中的短圈, 使得产生的LDPC码的Tanner图最小圈长为8. 由于该类码是准循环码以及其校验矩阵所固有的分层结构, 编码器和解码器都易于实现, 它们分别是线性可编和线性可译的. 所提出的LDPC码码率范围较大, 可以灵活选取. 利用迭代解码进行计算机仿真, 发现新的LDPC码比其他的规则LDPC码在编码OFDM系统中具有更好的性能.     

Suboptimal reliable guaranteed cost control for continuous-time systems with multi-criterion constraints

The suboptimal reliable guaranteed cost control （RGCC） with multi-criterion constraints is investigated for a class of uncertain continuous-time systems with sensor faults. A fauk model in sensors, which considers outage or partial degradation of sensors, is adopted. The influence of the disturbance on the quadratic stability of the closed-loop systems is analyzed. The reliable state-feedback controller is developed by a linear matrix inequalities （LMIs） approach, to minimize the upper bound of a quadratic cost fimction under the conditions that all the closed-loop poles be placed in a specified disk, and that the prescribed level of H∞ disturbance attenuation and the upper bound constraints of control inputs＇ magnitudes be guaranteed. Thus, with the above muki-criterion constraints, the resulting closed-loop system can provide satisfactory stability, transient property, a disturbance rejection level and minimized quadratic cost performance despite possible sensor faults.     

一类非线性系统的广义预测控制

对于时延的非线性系统,将其等价为含有纯滞后的时变线性系统,利用三次样条函数逼近时变参数,利用渐消记忆递推最小二乘法在线辨识多项式的参数以实现时变参数估计,将基于Hammerstein模型的非线性系统线性化.最后运用广义预测控制策略实现对该系统的仿真,结果表明被控对象在广义预测控制算法的控制下系统闭环稳定性好、稳态误差小.     

Error analysis for remote nonlinear iterative learning control system with wireless channel noise

In this paper, the iterative learning control problem is considered for a class of remote control system over wireless network communication channel. The control performance of remote iterative learning control (R-ILC) system is analyzed and an error boundary of the stable output of the R-ILC system is obtained for the boundary stochastic noise channel. Finally, we obtain some rules to reduce the fluctuation caused by wireless channel noise through the analysis results for fluctuation boundary. The simulation results prove the proposed rule is correct.     

Control of orbit and control of chaos in a class of dynamic system

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一类相似组合系统分散自适应模糊控制

针对一类具有函数控制增益的非线性相似组合大系统,基于一种修改的李亚普诺夫函数并利用Ⅱ型模糊系统的通用逼近能力,提出了一种稳定自适应分散模糊控制器设计的新方案。该方案能够避免现有的一些模糊控制器设计中对控制增益一阶导数上界的要求。通过理论分析,证明了闭环分散模糊控制系统是全局稳定的,跟踪误差收敛到零。     

Delay-dependent robust control for uncertain discrete singular systems with time-varying delay

The design problem of delay-dependent robust control For uncertain discrete singular systems with time-varying delay is addressed in this paper. The uncertainty is assumed to be norm-bounded. By establishing a finite sum inequality based on quadratic terms, a new delay-dependent robust stability condition is derived and expressed in terms of linear matrix inequalities （LMIs）. A suitable robust state feedback control law is presented, which guarantees that the resultant closed-loop system is regular, causal and stable for all admissible uncertainties. Numerical examples are given to demonstrate the applicability of the proposed method.     

Decentralized impulsive control for a class of uncertain interconnected systems

A great deal of stabilization criteria has been obtained from study of stabilizing interconnected systems. The results obtained are usually based on continuous systems by state feedback. In this paper, decentralized impulsive control is presented to stabilize a class of uncertain interconnected systems based on Lyapunov theory. The system under consideration involves parameter uncertainties and unknown nonlinear interactions among subsystems. Some new criteria of stabilization under impulsive control are established. Two numerical examples are offered to prove the effectiveness and practicality of the proposed method.     

Decentralized impulsive control for a class of uncertain interconnected systems

INTRODUCTIONWiththedevelopmentofscienceandtech-nology,thestructuresofcontrolsystemsaregettingmoreandmorecomplicated.Thiskindofsystemhasthecharacteristicoflargedimension,andin-terconnectionamongsubsystems.Generally,thiskindofsystemiscalledinterconnectedlargesystem.Thestudyofinterconnectedsystemsismotivatedbyquiteanumberofpracticalapplicationsrangingfrompowernetworks,transportation,aerospace,economics,management,andsoon.Thestrategiestocontrolinterconnectedsystemsaredividedintotwokinds:centr…     

Delay-dependent robust H∞ control for a class of uncertain switched systems with time delay

For linear switched system with both parameter uncertainties and time delay,a delay-dependent sufficient condition for the existence of a new robust H∞ feedback controller was formulated in nonlinear matrix inequalities solvable by an LMI-based iterative algorithm.Compared with the conventional state-feedback controller,the proposed controller can achieve better robust control performance since the delayed state is utilized as additional feedback information and the parameters of the proposed controllers are changed synchronously with the dynamical characteristic of the system.This design method was also extended to the case where only delayed state is available for the controller.The example of balancing an inverted pendulum on a cart demonstrates the effectiveness and applicability of the proposed design methods.     

Proportional-integral-derivative control of nonlinear half-car electro-hydraulic suspension systems

This paper presents the development of a proportional-integral-derivative (PID)-based control method for application to active vehicle suspension systems (AVSS). This method uses an inner PID hydraulic actuator force control loop, in combination with an outer PID suspension travel control loop, to control a nonlinear half-car AVSS. Robustness to model uncertainty in the form of variation in suspension damping is tested, comparing performance of the AVSS with a passive vehicle suspension system (PVSS), with similar model parameters. Spectral analysis of suspension system model output data, obtained by performing a road input disturbance frequency sweep, provides frequency response plots for both nonlinear vehicle suspension systems and time domain vehicle responses to a sinusoidal road input disturbance on a smooth road. The results show the greater robustness of the AVSS over the PVSS to parametric uncertainty in the frequency and time domains.