互联大系统动态输出反馈多重叠鲁棒分散关联镇定

针对一类具有网型拓扑结构的互联大系统,提出一种动态输出反馈多重叠鲁棒分散关联镇定方法.该方法将系统状态空间加以扩展,在扩展空间中将其分解为按循环逆序排列的一系列两两子系统对,并为每个子系统对分别设计使其关联稳定的鲁棒分散动态输出反馈控制器,将这些多重叠设计的控制器再收缩回原空间,实现控制律的协调.将该方法应用到一个四区域网型电力系统控制设计中,仿真结果验证了所提出方法的可行性和优越性.     

Pair-wise decomposition and coordinated control of complex systems

Pair-wise decomposition and coordinated control for complex interconnected systems with any information structure constraints are proposed in this paper. Based on the inclusion principle, a permuted inclusion principle is presented to expand the system into an expanded space, from which a recurrent reverse order of pair-wise subsystems is extracted. By a standard LQ control, pair-wise controllers can be designed to stabilize and coordinate the pair-wise subsystems. According to these controllers, a coordinated compensator of subsystem interconnections is introduced in order to obtain a coordination-based controller for the expanded system. Therefore, a coordinated controller of the system can be contracted from the expanded space under the conditions of the inclusion principle. Moreover, a sufficient condition of connective stability for the system is also proved by the Lyapunov function and M-matrix. A main advantage of the proposed decomposition and control is that it allows any variation of information structure constraints of the system, especially the increase and decrease of subsystem numbers. Finally, the effectiveness of the proposed methodology is demonstrated by an application of automatic generation control to a four-area electric power system.     

改进的网型结构电力系统鲁棒重叠分散控制

研究一类多区域互联电力系统的特殊重叠分解及其鲁棒分散控制问题,提出一种新的互联电力系统重叠分解的方法。该方法根据电力系统本身的结构信息约束和大系统包含原理的约束条件,对系统进行重叠分解处理,使原系统扩展成为两两子系统;然后,在有机结构控制(OSC)的线性矩阵不等式(LMI)方法的基础上,为系统设计了改进的鲁棒分散控制器。以一个4区域网型结构电力系统为例进行仿真研究,其结果表明,所设计的控制器较直接使用LMI方法能使系统具有更令人满意的控制性能。     

Stochastic inclusion principle applied to decentralized automatic generation control

An input-state-output inclusion principle for linear stochastic systems is proposed, with the emphasis on restriction and aggregation conditions for estimators and dynamic controllers. Inclusion of the LQG (linear quadratic Gaussian) optimal design is formulated and applied to the decentralized overlapping control of large-scale interconnected systems. Applications of the proposed methodology are illustrated using a stochastic model of automatic generation control (AGC) for interconnected power systems. Three types of overlapping decentralized and fully decentralized dynamic controllers, consisting of state estimators and feedback gains, are proposed for the cases of full and reduced measurement sets. An extensive analysis of both steady-state and transient regimes under a variety of operating conditions shows the superiority of the proposed AGC scheme with respect to the standard AGC designs.     

Contractibility of overlapping decentralized control

The purpose of this paper is to generalize the concept of contractibility of decentralized control laws in the Inclusion Principle. After a system with overlapping subsystems is expanded into a larger space, and decentralized control laws are formulated for the disjoint subsystems, the laws need to be contracted for implementation in the original space. We propose broader definitions of restriction and aggregation in the framework of inclusion, which provide more flexibility in the contraction phase of the expansion–contraction process. In particular, we discuss contractibility conditions for dynamic output controllers including state observers which have been of special interest in applications.     

Decomposition and decentralized control of systems with multi-overlapping structure

This paper considers decomposition and decentralized control of systems with multi-overlapping structure. It is demonstrated, using the inclusion principle, how the systems with longitudinal, loop and radial topologies can be expanded, and how the results can be used for designing controllers under information structure constraints. The proposed methodology is applied to automatic generation control (AGC) of an electric power system.     

重叠分解补偿阵的选择及对控制性能的影响

在大系统包含原理的框架下,提出了一种新的重叠结构分解补偿阵的选择方法,并分析了不同补偿阵对互联系统控制性能的影响。新方法根据补偿阵的选择条件,将补偿阵应满足的基本约束转化为对补偿阵中矩阵子块的约束,然后按照控制要求利用遗传算法对补偿阵进行优化。将该补偿阵选择方法应用于两区域重叠互联电力系统的自动发电控制（AGC）中,仿真结果表明,在设计时采用该方法选择的补偿阵使系统的分散AGC较传统选择方法具有更好的性能指标。     

Decentralized overlapping control of a formation of unmanned aerial vehicles

Decentralized overlapping feedback laws are designed for a formation of unmanned aerial vehicles. The dynamic model of the formation with an information structure constraint in which each vehicle, except the leader, only detects the vehicle directly in front of it, is treated as an interconnected system with overlapping subsystems. Using the mathematical framework of the inclusion principle, the interconnected system is expanded into a higher dimensional space in which the subsystems appear to be disjoint. Then, at each subsystem, a static state feedback controller is designed to robustly stabilize the perturbed nominal dynamics of the subsystem. The design procedure is based on the application of convex optimization tools involving linear matrix inequalities. As a final step, the decentralized controllers are contracted back to the original interconnected system for implementation.     

Robust Overlapping Guaranteed Cost Control of Uncertain State-Delay Discrete-Time Systems

This note presents a new extension of the inclusion principle to cope with the problem of designing robust overlapping controllers for state-delayed discrete-time systems with norm bounded uncertainties using the concept of guaranteed cost control. Expansion-contraction relations for systems and contractibility conditions for output guaranteed cost memoryless controllers are proved, including conditions on the equality of guaranteed performance bounds. The controllers are designed in the expanded space using a linear matrix inequality (LMI) delay independent procedure specifically adapted to this class of problems. The designed controllers are then contracted and implemented into the original system. The results are specialized for the overlapping decentralized control design. The method enables an effective construction of block tridiagonal controllers. A numerical illustrative example is supplied     

非线性扩展结构大系统自适应神经网络跟踪控制

针对一类非线性关联大系统在结构扩展时的跟踪控制问题, 提出一种采用自适应神经网络的控制方法. 该方法要求在不改变原结构系统控制律的前提下设计新加入子系统的控制律和自适应律, 使扩展后所有子系统都具有很好的跟踪性能. 这里主要利用神经网络的逼近功能以及Backstepping 技术来设计自适应律和控制律, 通过Lyapunov 理论证明在该控制器的作用下闭环系统的所有信号均是有界的, 并可使系统准确跟踪. 仿真结果验证了所提出方法的有效性.

     

Decentralized estimation and control with overlapping information sets

The objective of this note is to present a solution to the decentralized estimation and control problem for linear discrete-time varying systems, composed of overlapping subsystems. The solution is based on the expansion-contraction framework of the inclusion principle. It is shown how decentralized estimation and control laws can be independently computed for the expanded system, and then contracted for implementation in the original system to satisfy the overlapping information structure constraint.     

基于包含原理一般动态互联系统的分解与分散控制

针对一般结构互联系统的动态变化, 通过系统结构的描述, 以包含原理的多重叠分解为基础, 构建出适用于一般结构互联系统对对分解与重叠分散控制的扩展收缩变换矩阵、置换矩阵及相关的补偿矩阵; 然后根据所提出的子系统对的删除与添加方式, 构建出相应的删除矩阵与添加矩阵, 并将两者结合得到用于完成结构变化后的互联系统对对分解与重叠分散控制的结构变化矩阵, 从而实现具有一般动态结构互联系统的分解与分散控制; 最后以四区域互联电力系统AGC为例对其进行详细说明.

     

可逆冷带轧机速度张力系统的分散重叠控制

针对可逆冷带轧机速度张力系统的耦合和协调控制问题,提出了速度张力分散重叠控制方法.该方法首先利用包含原理和重叠结构分解,扩展原系统的状态空间,得到多个解耦的重叠子系统,并应用线性二次型(LQ)最优控制和顺序设计方法,设计各子系统的控制律.其次,将所设计的控制律收缩至原系统的状态空间,得到原系统的控制器.最后对某1422mm可逆冷带轧机的速度张力控制系统进行了仿真研究.结果表明,本文所提出的速度张力分散重叠控制方法能有效弱化速度与张力间的耦合,实现主轧机与左、右卷取机间的协调控制,同时改善了张力控制系统的动态性能,保证了轧机升降速时的张力控制精度.     

Decentralized overlapping tracking control

In this paper, a new methodology for decentralized overlapping tracking control of complex or large-scale systems is proposed. The methodology is demonstrated in the case of multiple systems moving in a plane. Starting from the given information structure constraints, the expansion/contraction paradigm based on the restriction conditions is applied. The local design provides tracking controllers for the extracted subsystems; contraction is done according to the inclusion principle and results in a stable controller provided the system graph has a directed spanning tree. A specific methodology based on sequential LQ optimization is proposed for local controller design.     

Stability of Large Space Structures Preserved Under Failures of Local Controllers

This note considers position and attitude control of large space structures composed of a number of subsystems (substructures) interconnected by flexible links. A decentralized control law of dynamic displacement feedback compatible with subsystems is applied under the assumption that sensors and actuators are collocated. It has been known that the overall closed-loop system is robustly stable against uncertainties in mass, damping, and stiffness, if rigid modes of each subsystem are controllable and observable. The objective of this note is to derive conditions for the overall system to be stable even when some local controllers fail. The conditions are expressed in terms of the stiffness (or damping) matrices and interconnection location matrices of the subsystems whose local controllers fail     

特殊的分散控制问题

主要研究一类特殊的分散控制问题,给出其可静态分散镇定的条件,并指出在一些情形下,不可能分散镇定整个系统的同时使各子系统也都稳定,也就是说,整个系统要达到分散镇定的结果,必须把部分子系统配置到不稳定状态.结果表明关联系统的稳定性有时主要依赖于子系统的协调性,不一定依赖于子系统的稳定性强度.     

Independent design of robust partially decentralized controllers

An independent design method for robust partially decentralized controllers is developed. In the proposed design method, the partially decentralized control system is first expanded to the nonsquare decentralized structure. Using the Internal Model Control parametrization, the independent design procedure for robust nonsquare decentralized controllers can then be applied directly to the expanded system. Two examples, including a nonlinear stirred mixing tank, are used to illustrate the developed design method and a comparison to a decentralized controller is made.     

Eigenstructure assignment by decentralized feedback control

An approach to eigenstructure assignment using decentralized control is introduced. First, several analytical results are presented to characterize the set of decentralized controllers which achieve desired eigenvalue assignment. Then, a method is proposed to assign eigenvalue and eigenvectors of a linear system simultaneously, using decentralized control. The method is applied to the control of a power system to illustrate its effectiveness     

Decentralized stabilization for expanding construction oflarge-scale systems

A decentralized stabilization problem compatible with expanding the construction of large-scale systems is considered. It is assumed that a large-scale system is obtained by adding new subsystems one after another. When a new subsystem is connected to an already interconnected portion, a local controller is designed for the new subsystem so that both the subsystem and the resultant expanded system are stable. The proper-stable-factorization approach is used for calculating the local controllers. Sufficient conditions on subsystems for such stabilization are presented. They are expressed in terms of the solvability of linear matrix equations over the ring of stable rational matrices     

A new approach to control design with overlapping information structure constraints

In this paper, a new strategy is proposed for decentralized state feedback design with overlapping information structure constraints. The method combines linear matrix inequalities and the inclusion principle in a way that eliminates controllability problems that are inherent to standard decentralized control design in the expanded space. This approach can be extended to include an important class of uncertain nonlinearities, and its validity is demonstrated through applications to strings of moving vehicles.