多变量自校正前馈控制器及其应用

本文提出了一种新的多变量自校正前馈控制器.该控制器不仅能完全消除可测干扰的影 响,而且能应用到多变量系统,实现自造应解耦控制.本文还介绍了该控制器如何实现多变量 解耦控制及其在多变量电加热炉上的应用.     

一种新的随机多变量自适应极点配置控制器

本文提出的随机多变量自适应极点配置控制器,由于采用了一种新的极点配置结构,它不仅可以避免求解伪交换矩阵方程而实现任意极点配置,跟踪时变参考输入,而且可以抑制随机噪声干扰.该控制器不仅可以控制开环不稳定或非最小相位系统,而且还可以控制具有任意、未知或变化的延时结构和具有任意输入输出个数的随机多变量系统。     

随机多变量系统的自适应容错控制

为保证控制系统在正常和故障状态下都能可靠安全地运行,本文将自适应控制方法和容 错技术结合,提出了一种适于随机多变量系统的新型自适应容错控制器.该控制器不仅适于 开环不稳定的非最小相位系统,而且当执行机构卡死或失效时仍能稳定工作,仿真结果验证了 本文算法的有效性.     

解谐最小方差自校正前馈控制器及其应用

本文提出了一种解谐最小方差自校正前馈控制器。该控制器将自校正控制的最优策略与经典的极点配置策略结合起来,因而具有两者的优点。该控制器不仅可以完全消除可测干扰的影响,而且可以应用于多变量系统实现自适应解耦控制。文中讨论了该控制器在多变量电加热炉中的工程应用。实时控制结果表明,自校正前馈控制器不仅能适应电网电压波动等因素引起的模型参数的改变,控温效果优于常规PID调节器,而且可使被控变量之间的耦合作用大大减小。     

多变量极点配置自适应动态解耦控制器

本文提出了一种以多变量极点配置为基础的自适应解耦控制器,该控制器不仅可以任意配置闭环系统的极点位置而且可以直接对闭环系统实现动静态解耦控制,仿真实验结果表明该控制器比一般的极点配置控制器具有更好的控制性能。     

一种新的间接自适应前馈控制算法及其应用

本文提出的单变量随机间接自适应控制算法适于控制大滞后的系统.它不仅能消除可测 干扰的影响,而且可以应用到多变量系统实现自适应解耦控制.该算法即使用于非最小相位 系统也具有全局收敛特性.本文还介绍了该算法在多变量电加热系统中的应用.     

一种简单的多变量自校正控制器及其在电加热炉上的应用

本文提出一种新的多变量自校正控制器,该控制器将最小方差策略和极点配置策略结合起来,从而具有两者的优点;该控制器可以控制具有不同传输延时的系统;算法简单。本文讨论了该自校正控制器在双输入双输出电加热炉上的工程应用。实时控制结果表明,该控制器不仅能适应电网电压波动等因素引起的模型参数的改变,控温效果优于常规PID调节器,而且使被控变量之间的耦合作用大大减小。     

自校正控制非最小相位的电加热系统

本文提出了一种简单的多变量极点配置自校正解耦控制器。该控制器不仅避免了在线求解矩阵方程和矩阵求逆运算而且实现了自适应解耦控制。该自适应控制器已被成功地应用来控制双输入双输出非最小相位的电加热炉。     

一种多变量广义最小方差自校正解耦控制器

本文对一类多变量系统给出了一种广义最小方差自校正解耦控制器,并讨论了它的收敛性.这种自校正控制器不仅能实现解耦控制,还可使解耦系统实现二次型性能指标最优和实现极点配置.数字仿真与混合仿真结果表明这种控制器性能良好。     

使用低阶参考模型的离散多变量MRACS

本文提出了一种高阶被控对象跟随低阶参考模型的离散多变量模型参考自适应控制系统(MRACS)的设计方法,它利用数字滤波器将系统降阶,通过求解p个一次代数方程而确定的自适应控制输入信号,能够使多变量被控对象的每个多输入单输出(MISO)子系统的输出渐近收敛到对应的单输入单输出(SISO)低阶参考模型的输出,提出的自适应控制器不仅避免了引进正反馈和辅助信号,而且实现了自适应解耦控制,仿真结果表明该控制器具有较好的控制性能。     

非线性广义最小方差控制律综述

如何设计简单的控制策略对复杂非线性系统进行控制是控制界还未解决的难题．非线性广义最小方差控制律的提出使得非线性控制器的设计可以基于更为一般的非线性模型，并且控制器易于实现．整个系统包含时滞环节，稳定的非线性输入子系统和一个可以用多项式或者状态空间描述的子系统．通过最小化由误差加权项、状态加权项和输入加权项组成的信号的方差得到优化控制器．在系统为开环稳定的情况下，可用史密斯预估器进行控制．本文首先介绍了非线性广义最小方差控制的发展进程，然后综述了基于状态空间和多项式描述的系统的非线性广义最小方差控制器的设计以及其现状和今后的发展方向．     

具有强相容参数估计的多变量自校正前馈控制器

本文提出了一种新的自校正前馈控制器.该控制器具有如下优点:1)可以控制具有任意 传输延时结构的随机多变量系统;2)可以控制开环不稳定或非最小相位系统;3)不加积分作用 可以自适应消除偏差和可测干扰对输出的影响,消除跟踪误差;4)具有全局稳定特性;5)参数 估计具有强相容性.     

网络环境下不敏感系统的分布式区域预测控制方法

针对二分图网络结构下的不敏感系统的可控性比较差的问题,本文提出了带有区域控制的分布式模型预测控制方法.该方法首先利用分支定界法对分布式控制系统结构进行最优设计;然后,结合区域控制提高控制系统的动态性能指标;最后,依据回路之间的关联性的强弱选择每个回路的控制方式(精确控制或区域控制).仿真结果显示带有区域控制的分布式预测控制系统的调节时间比没有带区域控制的分布式控制系统明显缩短;同时,通过对回路控制方式的选择增加了精确控制的智能体数量.仿真结果证明了利用分布式区域预测控制方法可以提高系统的容错性,通过对系统的可控性和关联性进行分析,可以在精确控制和区域控制之间寻找到最优组合,从而达到快速精确的控制效果.     

On the model-based networked control for singularly perturbed systems with nonlinear uncertainties

In this paper, the model-based networked control is addressed for a class of singularly perturbed control systems with nonlinear uncertainties. An approximate linear slow and fast control system of the plant, which can be obtained by omitting the nonlinear uncertainties, are used as a model to estimate the state behavior of the plant between transmission times. The stability of model-based networked control systems is investigated under the assumption that the controller/actuator is updated with the sensor information at constant time intervals. It is shown that there exists the allowable upper bound of the singular perturbation parameter such that the model-based networked control system is globally exponentially stable.     

Swing Suppression and Accurate Positioning Control for Underactuated Offshore Crane Systems Suffering From Disturbances

Offshore cranes are widely applied to transfer large-scale cargoes and it is challenging to develop effective control for them with sea wave disturbances. However, most existing controllers can only yield ultimate uniform boundedness or asymptotical stability results for the system’s equilibrium point, and the state variables’ convergence time cannot be theoretically guaranteed. To address these problems, a nonlinear sliding mode-based controller is suggested to accurately drive the boom/rope to their desired positions. Simultaneously, payload swing can be eliminated rapidly with sea waves. As we know, this paper firstly presents a controller by introducing error-related bounded functions into a sliding surface, which can realize boom/rope positioning within a finite time, and both controller design and analysis based on the nonlinear dynamics are implemented without any linearization manipulations. Moreover, the stability analysis is theoretically ensured with the Lyapunov method. Finally, we employ some experiments to validate the effectiveness of the proposed controller.      

Reset law design based on robust model predictive strategy for uncertain systems

In a continuous time control system, if some of the controller states are reset, certain limitations on the system response can be removed. Moreover, the stability and performance of such a reset control system may be improved. Resetting action has two main characteristics which should be determined: (a) when the controller states are reset and (b) how the after reset values of the controller states are determined. By defining a reset set, when the system states enter this set, the instants for the controller states reset, can be determined. This paper addresses the second question on how to determine the after reset values. In order to design a reset law for real time applications, a model predictive strategy is proposed that specifies the after reset values by minimizing a quadratic performance index. The quadratic minimization problem is converted to a LMI formulation and the reset law is determined by solving this LMI optimization problem at certain reset times. This approach is applied to a typical CSTR system to demonstrate the effectiveness of the proposed method for industrial process control application.     

Sliding mode control of discrete‐time switched systems subject to mode delays

This work considers the sliding mode control problem of a class of discrete‐time uncertain switched systems subject to detecting‐delay on mode signals, which may result in the asynchronous phenomenon between the controller and the switched system. Since the mode information of the controlled system is not available for the controller in time, a mode‐independent sliding surface will be introduced, by which an asynchronous sliding mode controller is designed, whose control gain and robust parameter will be changing according to the controller mode. In the analysis on the stability of the closed‐loop control system and the reachability of the specified sliding surface, the asynchronous characteristics are detailedly investigated. It is shown that the Lyapunov function may be not always decreasing along the state trajectories during the unmatched interval of controller modes and system modes. Nevertheless, it is proven that the state trajectories can be driven into a sliding region around the specified sliding surface in finite time. Finally, some numerical simulation results are provided.     

Almost output regulation of switched linear dynamics with switched exosignals

For systems with switched linear dynamics and affected by persistent switched exosignals, we propose a new hybrid control approach to achieve not only closed‐loop stability but also tracking and/or rejection of persistent references/disturbances generated by multiple exosystems, namely, output regulation. It is assumed that both controlled plant and exosystem are described by switched linear models. The proposed hybrid controller/output regulator is specified as a switching impulsive system, where the controller states will undergo impulsive jumps at each switching instant. Based on the average dwell time switching technique, it has been shown how to completely reduce the synthesis problem of the hybrid controller to a set of linear matrix equations and linear matrix inequalities. Both continuous‐time and discrete‐time cases are discussed. To demonstrate its usefulness, the proposed hybrid control method has been applied to solve the output regulation problem for a mechanical system. Copyright © 2017 John Wiley & Sons, Ltd.     

Synthesis and Viability of Minimally Interventive Legal Controllers for Hybrid Systems

In this paper, we study the control of Composite Hybrid Machines (CHMs) subject to safety specifications. CHMs are a fairly general class of hybrid systems modeled in modular fashion as the concurrent operation of Elementary Hybrid Machines (EHMs). The formalism has a well-defined synchronous-composition operation that permits the introduction of the controller as a component of the system. The task of a legal (safety) controller is to ensure that the system never exits a set of specified legal configurations. Among the legal controllers, we are particularly interested in designing a minimally-interventive (or minimally-restrictive) one, which interferes in the system's operation only when constraint violation is otherwise inevitable. Thus, a minimally interventive safety controller provides maximum flexibility in embedding additional controllers designed for other control objectives to operate concurrently, while eliminating the need to re-investigate or re-verify the legality of the composite controller with respect to the safety specification. We describe in detail an algorithm for controller synthesis and examine the viability of a synthesized controller as related to the possibility of Zenoness, where the system can undergo an unbounded number of transitions in a bounded length of time.     

Modified bang‐bang controller for maximal and minimal time optimal control problems

Recently, there have been a series of results regarding two time optimal control problems for a class of linear and nonlinear systems ‐ one is to keep the system states within certain bound for the longest time during feedback disruption and the other is to derive the system states to near the origin as fast as possible after feedback recovery, both under bounded control inputs. These are called maximal and minimal time optimal control problems, respectively. In the existing results, a bang‐bang controller has been commonly suggested as the actual implementation of the optimal controller. In this paper, we suggest a modified version of the bang‐bang controller which can also serve as an approximate optimal controller. Our proposed controller provides the (near) optimal performance with (i) possible reduction of a number of switchings; (ii) possible reduction of control input magnitude.