摘要:

The development of an expert system environment for the design of M1MO control systems using the frequency response approach is discussed. The aim is to provide assistance for non-experienced designers so that they can learn and gain experience of a specific area of control system theory. As a preliminary, we discuss the different configurations of expert systems used in control system design. The design heuristic is then declared, and followed by a comprehensive example. The implementation of our expert system is then illustrated, and a detailed application is also given.

ISSN:0020-7721    

DOI:10.1080/00207729308949633

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A problem of control of a mechanical system in a partly specified motion is studied. It is shown that the structure of differential-algebraic equations (DAEs) describing the problem may essentially differ from the structure of governing equations for a constrained mechanical system. The control forces chosen to realize the program constraints may have arbitrary directions with respect to the constraint manifold, and, in the extreme, they may be tangent. Thus, the index of the original DAEs of the problem may exceed three and a special approach to the problem solution has to be undertaken. Such an approach is proposed; a systematic formulation is given for the transformation of the DAEs into index-one DAEs or ODEs. Criteria for solvability of the problem are included.

ISSN:0020-7721    

DOI:10.1080/00207729308949634

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Symbolic algebra manipulation is applied computationally to the mechanical system described by the inverted pendulum of two links, to yield analytic roots of the open-loop characteristic equation obtained from the linearized, symbolic dynamic equations of motion of the system. Detailed analysis of the characteristic polynomial form is presented, together with conditions relating polynomial root properties to physical parameter inequalities. Finally, features of the theoretical form of the characteristic polynomial for the generaln-link system are proposed, by simple explication of results provided by this low order system, and also those existing for the corresponding single-link case which may be obtained and checked directly.

ISSN:0020-7721    

DOI:10.1080/00207729308949635

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The problems of measuring the systematic risk of a security are discussed. Prior research indicates that estimates for systematic risk, i.e. beta coefficients, are greatly affected by infrequent trading and the selected return interval. This is the case especially in thin stock markets. A lag distribution model to estimate betas is introduced. In addition, the empirical properties of these betas are compared with several alternative beta estimates using data from a thin security market. The empirical evidence suggests that the estimated betas based on this model are less biased by infrequent trading than the betas based on several other estimation procedures proposed in the literature.

ISSN:0020-7721    

DOI:10.1080/00207729308949636

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Based on the concepts of implicit system feedback, all polynomial matrix solutions to the polynomial dophantine equation are solved. The solutions are expressed in terms of a generalized state-space realization and a feedback gain. The explicit formulae for the solutions are derived in the closed form.

ISSN:0020-7721    

DOI:10.1080/00207729308949637

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A simple and powerful method for unstable model reduction has been developed in which the approach is based on the fact that translation transformations in thes-plane preserve the input-output properties of a system. Using translation transformations in the frequency domain it is possible to change the stability of the system without losing input-output information. Although balancing requires that the model be asymptotically stable, it reduces the model depending only on the information of input to state and state to output. The stability requirement comes from the computation of the controllability and observability gramians which are used for characterizing the contribution of the states to the input-output map. It has been shown in this paper that it is possible to use balancing to reduce the models of unstable systems by transforming them into the stable models, reducing the model order, and then transforming the models back. The method has been demonstrated by case studies.

ISSN:0020-7721    

DOI:10.1080/00207729308949638

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A reinforcement scheme for learning automata, applicable to real situations where the reinforcement received from the environment is delayed, is presented. The scheme divides the state space into regions following the boxes approach of Michie and Chambers. Each region maintains estimates of the reward characteristics of the environment and contains a local automaton that updates action probabilities whenever the system state enters it. Estimates of reward characteristics are obtained using reinforcement received during the period of eligibility. Results obtained through computer simulation of the inverted pendulum problem are compared with the adaptive critic learning developed by Bartoet al. (1983).

ISSN:0020-7721    

DOI:10.1080/00207729308949639

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor