Showing papers by "Edward J. Davison published in 1982"
TL;DR: In this article, a constructive algorithm for synthesizing a controller to solve the robust servomechanism problem for a decentralized system subject to the constraint that each control agent possesses only a limited knowledge of the model of the system to be regulated.
Abstract: This paper is concerned with the solvability and controller synthesis of the robust servomechanism problem for a decentralized system subject to the constraint that each control agent of the system possesses only a limited knowledge of the model of the system to be regulated, i.e., typically, each agent of a large-scale system possesses only a local model of the system, which may be different from each other and generally is incomplete. The question to be asked then is: given that each control agent does not possess a model of the complete large-scale system to be regulated, but only a partial model of the complete system, and given that there exists no central decision making authority, to what extent can one solve the decentralized robust servomechanism problem for the system in a sequential stable way [1]? It will be shown that there exists a solution to this decentralized synthesis problem if and only if there exists a solution to the decentralized robust servomechanism problem. A constructive algorithm for synthesizing a controller to solve this decentralized problem in this case is given. Some simple numerical examples are given to illustrate the results.
41 citations
14 Jun 1982
TL;DR: In this article, the problem of designing realistic decentralized controllers to solve the robust decentralized servomechanism problem is considered, and the method of design is based on extending the centralized design method of [2] to deal with the decentralized case.
Abstract: The problem of designing realistic decentralized controllers to solve the robust decentralized servomechanism problem [1] is considered in this paper. In particular, it is desired to find a decentralized controller for a plant to solve the robust servomechanism problem so that closed loop stability and asymptotic regulation occur, and also so that other desirable properties of the controlled system, such as fast response, low-interaction, integrity, tolerance to plant variations, constraints on gain magnitudes etc. occur. The method of design is based on extending the centralized design method of [2] to deal with the decentralized case. A number of examples are included to illustrate the design method.
21 citations
TL;DR: In this paper, the expanding system problem is considered in a controlled system with the property that robust tracking and regulation occurs in each of the system's local control agents, and that a new subsystem, which has outputs to be regulated, is to be connected to the system.
18 citations
TL;DR: An overview of recent results in the area of large scale control system design is given in this paper, in which an emphasis is placed on some of the more important differences occurring between the centralized and decentralized control problem.
3 citations
14 Jun 1982
TL;DR: In this paper, a model of interconnected systems with each subsystem having access to its local states is considered, where structural perturbations may occur, where each subsystem or group of subsystems may be connected or disconnected.
Abstract: A model of interconnected systems, with each subsystem having access to its local states is considered. It is assumed that structural perturbations may occur, where each subsystem or group of subsystems may be connected or disconnected. Two related problems, that of decentralized fixed modes and the solution to the decentralized servo-mechanism problem is analyzed. Conditions are given under which the interconnected system remains decentrally stabilizable and retunable under the structural perturbations. It is shown that these conditions are intimately related to the graph of the system and specifically to all "strongly connected subgraphs."
3 citations
01 Dec 1982
TL;DR: In this paper, the authors consider the problem of finding a robust servomechanism controller that achieves exact asymptotic tracking and regulation for a given class of reference and disturbance signals, and arbitrarily good approximate error regulation for other classes of input signals.
Abstract: This paper considers the problem of finding a robust servomechanism controller which achieves exact asymptotic tracking and regulation for a given class of reference and disturbance signals, and arbitrarily good approximate asymptotic regulation for other classes of reference and disturbance input signals. Necessary and sufficient conditions for the existence of such a controller, and a characterization of controllers which accomplish this are given. An explicit algorithm for such controllers is also given; in particular, it is shown that the design of such a controller can always be accomplished by using the cheap control design method as used in [1] for the multivariable robust servomechanism problem. A degenerate type of robust servomechanism controller (called a high gain servomechanism controller) consisting of only static feedback gains, is also given, which has the property that it produces arbitrarily good approximate regulation for all tracking/disturbance signals; thus this controller shows that dynamics in the feedback controller are not essential for achieving good approximate error regulation. Some numerical examples are included to illustrate the results.
01 Dec 1982
TL;DR: In this paper, the problem of designing realistic decentralized controllers to solve the robust decentralized servomechanism problem is considered, in particular, it is desired to find a decentralized controller for a plant to solve a robust servomain problem so that closed loop stability and asymptotic regulation occur, and also other desirable properties of the controlled system, such as fast response, low interaction, integrity, tolerance to plant variations, constraints on gain magnitudes etc.
Abstract: The problem of designing realistic decentralized controllers to solve the robust decentralized servomechanism problem [1] is considered in this paper. In particular, it is desired to find a decentralized controller for a plant to solve the robust servomechanism problem so that closed loop stability and asymptotic regulation occur, and also so that other desirable properties of the controlled system, such as fast response, low-interaction, integrity, tolerance to plant variations, constraints on gain magnitudes etc. occur. The method of design is based on extending the centralized design method of [2], [3] as is described in [4]. It is the purpose of this paper to outline some case studies of the design method when applied to plants varying from 2nd to 9th order with controllers of various complexity.