基于网络控制系统的感应电机非线性控制

针对网络控制系统中存在不确定时延的问题,讨论了网络条件下感应电机的建模与控制．首先基于感应电机的非线性数学模型,运用直接反馈化方法将其线性化,然后在线性化的基础上引入具有时延的网络控制系统,建立了感应电机的网络化控制模型．运用李亚普诺夫函数方法,给出了闭环系统渐近稳定的充分条件,基于相应的线性矩阵不等式可行解,可以求解状态反馈控制律．最后,仿真结果验证了该方法的有效性．     

A new approach to dynamic feedback linearization control of aninduction motor

A new approach to dynamic feedback linearization control of an induction motor is given, Previously, it has been shown that the dynamic model of an induction motor, consisting of speed, stator currents, and rotor flux, is dynamically feedback linearizable. However, the controller and transformation were valid only as long as the motor torque was nonzero and the methodology required switching between two computationally complex transformations. Here it is shown that by considering the direct-quadrature model of the induction motor, a single dynamic feedback linearizing transformation exists and is valid (essentially) as long as the (magnitude of the) rotor flux is nonzero. Furthermore, the resulting control computations are well within the capabilities of contemporary microprocessor technology     

Absolute stability and stabilization for Lurie networked control systems

This paper investigates the problem of absolute stability and stabilization for networked control systems (NCSs) with the controlled plant being Lurie systems (Lurie NCSs), in which the network‐induced delays are assumed to be time‐varying and bounded. By considering the relationship between the network‐induced delay and its upper bound, an improved stability criterion for networked control system is proposed. Furthermore, the resulting condition is extended to design a state feedback controller by employing an improved cone complementary linearization (ICCL) algorithm. A numerical example is worked out to illustrate the effectiveness and the benefits of the proposed method. Copyright © 2010 John Wiley & Sons, Ltd.     

改进的时延丢包网络控制系统的分析和控制

将网络控制系统建模为时变时滞系统模型,考虑有界、时变时延和丢包的网络控制系统的稳定性分析和控制器设计问题。首先构造一个新的分段Lyapunov-Krasovskii泛函,充分利用时延上下界信息,然后结合更紧的有限和不等式处理时滞区间,得到具有较小保守性的稳定性准则,基于一种改进的锥补线性化迭代算法给出状态反馈器设计方法,证明中没有引进模型变换和自由矩阵,减少了计算上的复杂性。通过实例表明上述方法的有效性。     

电流滞环控制PWM逆变器异步电动机的非线性解耦控制系统

本文针对电流滞环控制PWM逆变器异步电动机系统这一非线性、多变量、强耦合的控 制对象,采用非线性变换和非线性反馈,实现了系统的动态解耦和全局线性化.其中关键问 题是对合性条件的满足,从而分解成线性化的转速子系统和转子磁链子系统,两个子系统的 调节器可按古典线性理论设计.最后,用8096十六位单片机实现非线性解耦控制算法,组成 了交流变频调速系统,并给出实验结果.     

Dynamic feedback linearization of the induction motor

Dynamic state feedback is used to achieve feedback linearization of the induction motor. It is shown that the sixth-order nonlinear dynamical model of the induction motor consisting of rotor speed, two stator currents, two rotor fluxes and an integrator in the feedback controller can be made equivalent to two third-order decoupled linear systems by nonlinear state feedback through the stator input voltages. It is further shown that a nonsingular dynamic feedback linearizing transformation exists as long as the (electromagnetic) torque put out by the motor is nonzero     

基于自抗扰技术的网络化无刷直流电机控制系统时延补偿

采用自抗扰控制技术解决网络化无刷直流电机转速控制系统的时延补偿问题. 首先, 建立含有时变网络诱导时延的无刷直流电机控制系统模型, 并将时变时延引起的不确定动态描述为系统模型的不确定性; 然后, 设计自抗扰控制器, 对时延引起的不确定动态进行动态线性化补偿, 从而消除时变时延对系统性能的影响; 最后, 通过仿真研究表明了所设计的自抗扰补偿方法的有效性和优越性.

     

基于模糊云理论模型的智能配电云网络化控制识别方法

由于基于传统的不确定时滞鲁棒控制系统不能满足新型电力云网络化控制用户的需求,提出了一种基于模糊云理论系统模型的感知智能配电云网络化控制识别方法,该方法采用优化传统数据值和电力云网络化控制数据的一种云理论系统模型,并用云理论结果代替被控节点预测值,攻破了不确定滞鲁棒控制系统控制效果不能及时反馈的问题,同时将供电系统性能指标引入到电力云网络化控制计算器中,运用性能指标的云模型中正向运算法修正加权系数,实现了感知智能配电云网络化的最优控制。基于实验仿真证明,该识别方法可以优化传统的不确定滞鲁棒控制系统,并具有良好的适应性、鲁棒性、控制性,同时可以进一步改善智能配电云网络化控制的各种性能指标。     

基于滑模观测器的直线伺服系统反馈线性化速度跟踪控制

在许多高速、高精的直线伺服系统中,要求能实现对速度的快速精确跟踪,但其模型的非线性和变量间的耦合给控制带来难度.对高速、高精速度跟踪控制中,电流和速度的变化过程在时间尺度上相对接近,不能简单地采用磁场定向矢量控制方法实现静态解耦,否则电流和速度间的非线性耦合将破坏速度跟踪品质.采用状态反馈线性化方法来实现永磁直线同步电动机(PMLSM)模型的精确线性化和动态解耦.利用非线性坐标变换和非线性反馈将系统解耦成独立的线性电流子系统和速度子系统.通过扩展滑模观测器来实现对所需要的动子速度、加速度和负载扰动的鲁棒观测.并利用李雅普诺夫理论对由反馈线性化和滑模观测器构成的非线性闭环系统的稳定性进行了证明.仿真结果表明该方案使PMLSM伺服系统具有良好的鲁棒速度跟踪性能.     

STATE FEEDBACK CONTROLLER DESIGN OF NETWORKED CONTROL SYSTEMS WITH PARAMETER UNCERTAINTY AND STATE‐DELAY

This paper is concerned with the controller design of networked control systems. The continuous time plant with parameter uncertainty and state delay is studies. A new model of the networked control system is provided under consideration of the nonideal network conditions. In terms of the given model, a controller design method is proposed based on a delay dependent approach. The maximum allowable synthetical bounds related with the discarded data packet and network‐included delay and the feedback gain of a memoryless controller can be derived by solving a set of linear matrix inequalities for the stabilizablity of the networked control system based on Lyapunov functional method. An example is given to show the effectiveness of our method.     

基于Smith预估补偿的网络控制系统仿真研究

针对网络控制系统中前向通道和反馈通道同时存在随机延迟的问题,提出了一种基于神经元控制器的Smith预估器的设计方案。利用根轨迹法分析了随机延迟对网络控制系统稳定性的影响。结合不完全微分先行PID控制算法,建立了Smith预估模型,在模型不完全匹配的情况下得到较好的控制性能。以直流电机为被控对象进行仿真研究,仿真结果表明该方法的有效性。     

基于无源控制的无速度传感器异步电机调速控制

建立其交流异步电机的欧拉—拉格朗日数学模型,再以无源控制理论实现电机调速控制。为了转速反馈的准确性,加入了转速估算环节。充分利用被控系统已有的结构,直接比较给定的电磁转矩和估算的电磁转矩,运用PI闭环控制构造出转速信号。在Simulink中搭建仿真模型进行实验,仿真结果表明：此控制方法对交流异步电机速度控制具有较好的静/动态性能和抗干扰性。     

Robust speed control of induction motors using position and currentmeasurements

A nonlinear robust output feedback control is designed for a sixth-order model of an induction motor. The control uses only measurement of the rotor position and stator currents. It contains two observers, a second-order observer to estimate the rotor flux from the stator current and a third-order high-gain observer to estimate the rotor speed and acceleration from its position. The control is robust to uncertainties in the rotor and stator resistances, and a bounded time-varying load torque. It guarantees that the speed tracking error can be made arbitrarily small by choice of certain design parameters. Moreover, when the speed reference and load torque are constant, it ensures asymptotic regulation. Simulation results agree well with the analysis     

传输时延和时钟同步对以太网控制系统的影响

在分析报文传输时延和时钟同步精度对EPA网络(工业以太网)控制系统的实时性和稳定性的影响的基础上, 提出了新的基于马尔科夫链的时延模型. 给出了在系统稳定的情况下, 通信宏周期、协议传输时延和时钟同步精度应满足的条件. 建立了无丢包情况下的EPA网络控制系统模型. 提出了EPA控制系统稳定时, 可以设置的最小通信宏周期的计算方法.     

神经网络预测远程控制系统中信息延时的研究

针对网络控制系统中前向通道和反馈通道同时存在随机延迟及延时不确定的问题,通过实例分析了随机延时对闭环控制系统影响的根源,提出了通过基于神经网络的预测控制方法解决存在网络随机延时的控制系统闭环控制的可行性。仿真结果表明该方法能够反映并预测该测量数据所代表的网络路径之间的时延特性,并能在基于Internet的闭环控制系统的设计中有效地替代实际网络进行研究;而所用的方法具有快速、准确的特点,能用于在线学习网络模型并对网络的时延值进行预测,为基于Internet的远程闭环控制提供了新的思路。     

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.     

面向网络诱导时延和数据包丢失补偿的网络化广义预测控制

针对网络化控制系统中存在的网络诱导时延和数据包丢失, 考虑了网络化广义预测控制问题. 基于多个数据打包传送的通讯方式以及网络诱导时延和数据包丢失预先可知的假设, 提出了一种采用最小预测步长和预测控制增量向量分别补偿网络诱导时延和数据包丢失对系统性能影响的新方法, 给出了相应的网络化模型预测算法和网络化滚动优化算法, 对于被控对象参数未知或缓慢变化的情况, 给出了基于递推最小二乘辨识改进算法的网络化反馈修正算法, 通过仿真验证了所提出网络化算法的有效性.     

基于SVPWM的无速度传感器矢量控制的研究

介绍了空间电压矢量脉宽调制(SVPWM)控制策略在无速度传感器矢量控制系统中的实现,在此基础上给出了基于DSP的全数字化调速系统,并分别建立了改进的电压型转子磁链观测模型和PI自适应速度估算模型.实验结果表明所采用的控制方法正确可行,控制系统具有良好的性能.     

Robust Time-varying H∞ Control for Networked Control System with Uncertainties and External Disturbance

In this paper, the robust H∞ control problem is developed for a class of linear time-varying networked control system (NCS) with uncertainties and external disturbance. In network, the network-induced delay and packet dropouts are simultaneously considered. Firstly, a discrete-time switched system model is established based on the signals transmission delay in network. Then, a time-varying H∞ controller is designed. Such the controller can vary according to delay in network. Furthermore, by constructing delay-dependent Lyapunov-Krasovskii functional, a sufficient condition is given to guarantee that the closed-loop system is stochastically stable with an H∞ disturbance attenuation level in terms of nonlinear matrix inequalities. In order to solve the controller gain, the cone complementarity linearization (CCL) algorithm is employed. Finally, a networked DC motor control system is analyzed to illustrate the effectiveness of the proposed method.     

Design of networked control systems with bounded arbitrary time delays

This paper is mainly concerned with the model predictive control (MPC) of networked control systems (NCSs) with uncertain time delay and data packets disorder. The network-induced time delay is described as bounded and arbitrary process. For the usual state feedback controller, by considering all the possibilities of delays, an augmented state space model of the closed-loop system, which characterizes all the delay cases, is obtained. The stability conditions are given according to the Lyapunov method based on this augmented model. The stability property is inherited in MPC which explicitly considers the physical constraints. A numerical example is given to demonstrate the effectiveness of the proposed MPC.