Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> A specific type of interconnection is examined with regard to three nonlinear subsystems in this communique. Further, the two possibilities of this specific linear interconnection are investigated in detail. For each kind of interconnection, conditions for the global stability of the overall system are derived, via the Popov method, which are simple and easy to apply. The conditions are rather conservative in nature, though a certain amount of flexibility does exist in the choice of the various parameters in the event of constraints other than stability are to be satisfied. An example is included to illustrate the utility of the conditions. <s> BIB001 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> One of the important control problems in the operation of an interconnected power system is load-frequency control (LFC). In this paper the LFC problem is investigated using a recent result in modern control theory known as disturbance-accommodation control (DAC). It is shown that the optimal accommodation of load disturbance can lead to significantly better performance than that of conventional controllers. It is further shown that the complete obsorption of all disturbance effects in the class of power systems considered is impossible. Nevertheless, the disturbance effects in system frequency can be cancelled completely. Simulation results are presented for the case of one area system and the data clearly demonstrate the degree of performance improvement made possible by a DAC controller. <s> BIB002 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> Abstract A method for proving the stability of systems composed of subsystems with similar dynamics through symmetric or nearly symmetric interconnections is proposed. The subsystems are described by a common approximate state space model and an individual upper bound of the modelling errors. For the stability of the symmetric core of the overall system a necessary and sufficient condition is given in terms of two matrices which have only the same order as the subsystems. For the stability of the overall system a sufficient condition is derived that can be successfully used for typical large-scale systems with a large number of subsystems and strong subsystem interactions. This is demonstrated by proving the stability of a large multiarea power system, for which stability tests that are based on weak subsystem interactions fail. <s> BIB003 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> Abstract A number of large-scale interconnected systems often encountered in practice are composed of subsystems with similar dynamics interconnected in a symmetrical fashion and the synthesis of controllers for such systems must exploit the special structural properties in order to avoid overly conservative designs and to take advantage of the possible beneficial effects of the interconnections. An analysis of some important qualitative properties of such symmetrically interconnected systems focussing on the spectrum characterization, controllability and observability, and the solutions of the algebraic Riccati equation and the matrix Lyapunov equation is conducted in this paper and procedures for constructing the solutions to the analysis problems at the overall system level from the computationally simple subsystem level solutons are developed. A decentralized controller design procedure is presented as an illustration of the utilization of the available structural information in addressing synthesis problems. Numerical examples are included to demonstrate the superiority of the presented designs over the use of existing approaches which do not take full advantage of the structural knowledge in these large-scale systems. <s> BIB004 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> Large scale control systems results of multivariable feedback systems models and structure of interconnected systems decentralized stabilizability the decentralized stabilization and pole assignment optimal decentralized control stability analysis of interconnected systems decentralized design for strongly coupled subsystems decentralized design for weakly coupled systems decentralized PI controllers strongly coupled symmetric composite systems survey of the results and open problems in feedback control of large-scale systems. <s> BIB005 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> This paper is concerned with control of plants composed of n similar interacting subsystems. Such plants are common in practice and include paper machines, distribution networks, coating processes, and plants consisting of units operating in parallel. The transfer function matrices for these systems are block symmetric circulant. For H∞- and H2-optimal control, controller synthesis is simplified by considering n2 + 1 independent problems of dimension n times smaller than the original problem. For the case of H∞-optimal control this also yields ‘super-optimality’, where the H∞ criterion is optimized in n directions, and not only in the worst direction. If the offdiagonal blocks (‘interactions’) are identical the matrix is termed block parallel, and controller synthesis involves only two independent subproblems of the same dimension as the subsystems. This leads to a dramatic reduction in dimension for systems composed of many subsystems. <s> BIB006 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> Abstract This paper discusses the problem of designing stabilizing controllers for uncertain symmetric composite systems. A procedure of designing a linear (decentralized) feedback control law which will stabilize a given symmetric composite system with uncertainty is presented by using the Riccati equation approach. A feature of the procedure is that the stabilizing control law can be conducted by solving two lower-order Riccati equations (or inequalities). The uncertainties considered in the systems may be time-varying. However, the values of the uncertainties are constrained to lie within some known admissible bounds. <s> BIB007 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> In this paper, by adding auxiliary controllers, a holographic robust stabilizing controller is designed for a class of nonlinear similar composite systems with uncertain parameters. It follows that similar structure can simplify the analysis and design of composite systems and it is closely connected with holographic property. Finally, numerical simulation is presented to illustrate the validity of this paper. <s> BIB008 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> Discusses a class of large-scale systems composed of symmetrically interconnected identical subsystems. We consider the decentralized H/sub /spl infin// control design problem and study the fault tolerance of the resulting system. By exploiting the special structure of the systems, a sufficient condition for the existence of a decentralized H/sub /spl infin// controller is derived. Moreover, for the nominal case as well as for contingent situations characterized by control channel failures, the poles and the H/sub /spl infin//-norm of the closed-loop system can be calculated easily based on certain systems of reduced dimensions. Consequently, the tolerance to actuator failure can, be easily tested. <s> BIB009 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> Describes the similarity between two nonlinear control systems, shown in a large number of physical systems of interest in many engineering applications. By utilising similar information, robust controllers for large-scale nonlinear similar composite systems with uncertain parameters are proposed. The results obtained show that the similar structure of composite systems possesses a holographic property and can simplify the analysis and design of nonlinear systems. <s> BIB010 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> Regional pole assignment for a kind of uncertain symmetric circulant composite system by state feedback in a specified disk is discussed. The 'decentralised D stabilisation controllers' have been obtained by making use of the special structure of the system. Thus the problem of assigning the poles in a specified disk for such an uncertain system with N /spl middot/ n dimensions can be transformed into the subproblems for N/2+1 or (N+1)/2 uncertain systems with n dimensions. The central D stabilisation controller for such a system has the same block symmetric circulant structure as the original system and can be constructed by the 'decentralised D stabilisation controllers'. <s> BIB011 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> To control the large scale systems is important. In this paper, a multi variable non-linear system (two inverted pendulum coupled by a spring) is output feedback linearized and the system is generalized in two subsystems and decentralized dynamic output feedback basis on lyapunov equation is applied. Using this model, the large scale system can be formulated, designed and generalized to be controlled. <s> BIB012 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> This paper investigates the stabilization and synchronization of complex dynamical networks with different dynamics of nodes by using decentralized linear control and linear matrix inequality. We propose a dynamical network model with similar nodes that the dimensions of node dynamics are different. For this kind of network model, decentralized linear controllers are designed for the stabilization and synchronization. In addition, the synchronization manifold is defined as an invariant manifold, which is regarded as the generalized case of the networks with same node dynamics. Some criteria for the synchronization of networks are derived in this paper. Finally, numerical examples are presented to verify the theoretical results. <s> BIB013 </s> Decentralised control for complex systems - an invited survey <s> System structure-based decentralised control <s> Thank you for downloading control of manipulation robots theory and application. Maybe you have knowledge that, people have look hundreds times for their chosen novels like this control of manipulation robots theory and application, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they cope with some infectious bugs inside their computer. <s> BIB014
System structure plays an important role in control design. One of the fundamental properties of large scale interconnected systems in the real world is that the operational characteristics of the components (subsystems) may be very similar and indeed symmetrically identical. For example, in a manufacturing process, in order to produce the same engineering components in large quantities, many identical or similar machine tools (isolated subsystems) are interconnected together to form a large-scale system to complete the task. The key structural characteristics existing in large-scale interconnected systems relate to symmetry BIB005 and similarity BIB012 . By using such structural characteristics, design and analysis for complex interconnected systems can be simplified. Study on symmetric interconnected systems dates back to at least 1980 BIB001 . Based on the circulant structure of transfer function matrix, a class of symmetrically interconnected plants is introduced in BIB006 . This study shows that the symmetric structure employed produces a dramatic reduction in dimension for interconnected systems composed of a set of subsystems. It should be pointed out that the study of symmetric interconnected systems has mainly focused on the linear case and a suitable formulation for the symmetric structure of nonlinear interconnected systems has not been available. Symmetric interconnected systems can be described bẏ Hx j where x i ∈ R n , u i ∈ R m and y i ∈ R p are the system states, inputs and outputs respectively, and A 1 , B 1 , C 1 and H are constant matrices with appropriate dimensions. System (9) can be written in a compact form aṡ where This class of large-scale interconnected systems is representative of systems which widely exist in the real world BIB004 such as the multi-machine power system discussed in BIB002 and industrial robot manipulators considered in BIB014 . The formulation has thus been extensively studied, and many results have been achieved, for example,  , BIB007 and BIB009 . The output regulation problem was solved for a class of strongly coupled symmetric interconnected systems in  . BIB007 proposed a set of conditions described by two Riccati equations under which a control scheme is developed such that the corresponding closed-loop system is asymptotically stable. By employing the symmetric structure of the interconnected systems, a set of sufficient conditions for the existence of a decentralised H ∞ controller is derived, and the problem of fault tolerance of the resulting system was considered in BIB009 . Recently, pole assignment for uncertain symmetric circulant composite systems is considered in BIB011 where a decentralised stabilisation controllers are designed to place all of the poles of the system into a specified disk which is also called D stabilisation. A class of interconnected systems with similar subsystems were studied in BIB008 . The exact definition of similar structure for nonlinear interconnected systems was introduced for the first time in  , and can be briefly summarised as follows. Consider the following two control systems where x 1 , x 2 ∈ R n , u 1 , u 2 ∈ R m and y 1 , y 2 ∈ R p are the system states, inputs and outputs respectively. Definition 3: Systems ∑ 1 and ∑ 2 are said to have similar structure, if there exists a diffeomorphism T : m and a C ∞ non-singular function matrix β(·) ∈ R m×m such that the closed-loop system formed by applying the control to system ∑ 1 , can be expressed in the form of ∑ 2 in the coordinate x 2 defined by T . For large-scale interconnected/composite systems with similar structure, two types of discontinuous nonlinear decentralised controller with holographic structure are proposed to stabilise the system asymptotically by exploiting the similar structure  BIB010 . These are easily implemented compared with general nonlinear controllers under the assumption that all the system states are available for design  BIB010 . A static output feedback controller with holographic structures was proposed in and dynamical output feedback control schemes have also been presented in and BIB012 . However, the similar structure defined through Definitions 3 and 4 does not consider the structure of the interconnections. It may be very interesting to study how the structure of interconnections affects the decentralised control design and the interconnected system analysis. Modelling the similar structure of nonlinear interconnections is challenging but may be useful for the study of decentralised control. It should be noted that for a symmetrically interconnected system (9), if the matrix A in system (10) has the following form, where A 0 , M and L are constant matrices with appropriate dimensions, then the corresponding systems are also called similar interconnected systems BIB003 . Study of such a class of systems has obtained interesting results (see e.g., BIB003 Zhang, 1995, 1996) and a class of interconnected systems with similar nodes is considered in BIB013 . It should be noted that in recent years the study of symmetric or similar interconnected systems has been limited. The means to describe a similar interconnected system by considering the structure of the interconnections is still an open problem.