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In this report, an algorithm for adaptive control of continuous time single-input single-output systems is presented. With the hybrid approach, the control structure involves a continuous as well as a discrete time part, instead of being totally discrete or totally continuous as in previous approaches. The system is sampled and the adaptive gains updated at a variable rate varying with the magnitude...
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,...
In the design of efficient schemes for signal processing and decision making in large-scale systems, reliable operation is a factor of major concern since a frequent source of failure is the loss of information transfer between different parts of the system. This paper presents a new iterative procedure for the design of reliable decentralized stabilizing controllers for a large-scale system which...
The purpose of this paper is to present a detailed study of the inclusion concept in dynamic systems, which is a suitable mathematical framework for comparing systems with different dimensions. The framework offers immediate results in reduced-order modeling and the overlapping decentralized control of complex systems. The presentation, which is limited to linear constant systems, relies on both the...
In this work a MIMO self-tuning controller with on-line adjustment of the control weighing matrix is presented. The algorithm considered is a MIMO generalization of the SISO controller presented by Clarke [1]. On line adjustment is done through the utilization of the estimator covariance matrix trace.
The costate prediction method of hierarchical control of non-linear systems is based on two substitution relations for the first- and second-level problems in a multilevel formulation. The method has shown superior computational behavior for unretarded systems as compared to other schemes such as goal coordination or interaction prediction. In this paper the costate prediction is extended to retarded...
This paper presents a survey of human information processing and associated inference analysis in decentralized organizations as a large scale systems problem. One purpose of aids for inference analysis is to assist humans in using techniques which allow them to make better use of information. The use of hierarchical systems concepts with structured logical reasoning protocols is discussed and illustrated...
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 relationship between decentralized fixed modes and decentralized stabilization using stationary state feedback is investigated for a special class of controllable system structures. Several examples are presented to illustrate the main results.
Freight transport demands a large share of energy resources in India. The present study obtains the optimal shares of the three modes of traction in Indian Railways in the year 2000 AD for a given level of forecasted demand and constraints on electrification and dieselisation. Policy implications of this study for energy planning in Indian Railways are discussed.
This paper relates the various controversies of economic development to the limitations of the models underlying the specialist judgements. The paper further relates the limitations of these models to the limitations of the methodological tools used and advocates a radical change in methodological thinking for improving the practical utility of the analyses of economic development.
We consider the problem of detection using distributed sensors and limited communication. In particular we examine the case of detecting a known signal in noise which is correlated between sensors, and that of detecting an unknown signal in white noise. As the optimal detection law cannot be determined, we optimize over a class of suboptimal detection laws based on local likelihood ratio tests. Numerical...
A computationally feasible methodology will be presented for state estimation and failure identification in discrete-time nonlinear stochastic systems. The procedure involves using multiple hypothesis testing to isolate failures in both system inputs and outputs. The method is obtained by extending Friedland's results [1] for separate bias estimation and Caglayan's results [2] for simultaneous detection...
A distributed sensor network (DSN) provides a very rich scenario for the study of distributed estimation problems. Two important distributed estimation problems in DSN which hitherto have not received much attention in the literature are considered in this paper. The first problem is distributed multi-target tracking and classification. A distributed multi-target tracker and classifier, obtained by...
Computer-aided diagnostic techniques are successfully applied to on-line signal validation in an operating nuclear reactor. To avoid installation of additional redundant sensors for the sole purpose of fault isolation, a real-time model of nuclear instrumentation and the thermal-hydraulic process in the primary coolant loop is developed and experimentally validated. The model provides analytically...
The Space Shuttle Flight Control System is required to be two-fault tolerant; i.e., the system must be capable of returning to a landing site even though two system failures occur. This is referred to as fail-operational/fail-safe performance. To achieve this fault tolerance, the avionics equipment is made redundant. A redundancy management (RM) system is required to detect failures and reconfigure...
In this paper the Generalized Likelihood Ratio (GLR) method for maneuver detection and estimation is applied to a generic surface-to-air engagement. In the case at hand, the technique results in system model nonlinearities which are incorporated in the algorithm to yield an "extended GLR." By employing Monte Carlo simulations, the detection and maneuver estimation performance of the GLR...
Large industrial projects and processes which consists of a member of subprojects or subprocesses are modelled as two level large scale dynamic systems. The control functions are divided into two categories. The first is a set of local controllers which are functions of the local states of the subproject. These controllers are used to control the subprojects executions irrespective of the interconnections...
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