摘要:

The concept of right invertibility (functional reproducibility) of a general multi-variable discrete time analytic non-linear system is discussed. Two different types of right inverses are considered, one being a special case of the other. The sufficient conditions for both types of right invertibility are given and for invertible systems the right inverses are constructed.

ISSN:0020-7179    

DOI:10.1080/00207179008934047

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

We consider a flexible spacecraft modelled as a rigid body rotating in inertial space; a light flexible beam is clamped to the rigid body at one end and is free at the other. The equations of motion are obtained by using free-body diagrams. It is shown that suitable boundary controls applied to the free end of the beam and a control torque applied to the rigid body stabilize the system. The proof is obtained by using the energy of the system as a Lyapunov functional.

ISSN:0020-7179    

DOI:10.1080/00207179008934048

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Power system stabilizers have been widely used and successfully used for the improvement of generator and power system damping. However, a fixed parameter system stabilizer tends to be sensitive to variation in generator dynamics so that, for operating conditions away from those used for design, the effectiveness of the stabilizer can be greatly impaired. A self-adaptive power system stabilizer is introduced based on a bang-bang pole-shifting approach and a second-order predictive model. The resulting controller provides a highly effective aid to system damping at a low computational cost, and the capabilities of the stabilizer are demonstrated by both digital simulation and real time tests on a micro-alternator system.

ISSN:0020-7179    

DOI:10.1080/00207179008934049

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Implicit pole-assignment self-tuning algorithms are treated where the controller parameters are directly estimated from input-output data. Most algorithms based on pole-assignment are explicit schemes involving a parameter estimation and synthesis stage to obtain controller parameters. The object of the work reported here is to have an algorithm that has the robustness of pole-assignment and the simplicity of the implicit approach.

ISSN:0020-7179    

DOI:10.1080/00207179008934050

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A new technique is presented for the analysis of non-linear stochastic systems in which they are represented by a series of non-linearly coupled linear systems. Considerable insight is gained in the approximation of non-linear stochastic systems by linear systems and in the use of describing functions. A measure of the error and second-order correction terms for the linear approximation are obtained. The analysis is extended to the non-zero mean case.

ISSN:0020-7179    

DOI:10.1080/00207179008934051

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A complete understanding of the accuracy for describing function methods for nonlinear stochastic systems is obtained in terms of a 'filtering hypothesis’. The insight gained is exploited to justify the use of ∥ΦgΦω∥2as a measure of error in approximating non-linear systems. The non-linear quadratic gaussian (NLQG) design methodology is shown to be consistent with the use of describing functions being reasonably accurate. Various approximation schemes for estimating the accuracy of linearized representations of non-linear systems are developed. It is concluded that a systematic approach to the use of describing functions has been developed and that they constitute a useful approach to a wide range of non-linear systems.

ISSN:0020-7179    

DOI:10.1080/00207179008934052

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The classical gain/phase relations obtained by Bode for minimum-phase continuous-time systems can be used to establish bounds on the performance of feedback systems. It is shown that completely analogous relations can be obtained for discrete-time systems, and can be used for the same purpose. In particular, the limitations imposed by plant zeros and poles which lie outside the unit circle are investigated, for both genuine discrete-time systems (namely those defined by difference equations) and for sampled-data systems. One of the results shows that sampled-data systems may practically be unstabilizable if their unstable poles lie outside a particular circular region. The intended application of these results is to allow preliminary screening of proposed specifications for feasibility (in a CAD system), before embarking on a detailed design.

ISSN:0020-7179    

DOI:10.1080/00207179008934053

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The roll motion and stability of a typical fishing vessel in British Columbia have been investigated using the Mathieu differential equation. The response of the system has been obtained for regular sinusoidal waves of various frequencies and amplitudes. Three cases, undamped, linearly and non-linearly damped have been studied and the corresponding Mathieu charts calculated. The effect of damping on the system's response and phase portrait are shown.

ISSN:0020-7179    

DOI:10.1080/00207179008934054

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The role of the structural properties of large scale systems for the synthesis of feasible control schemes is investigated. The feasibility of considering a state variable as an output (control objective) of a system is expressed via the concepts of multi-input connectability and structural functional controllability. It is shown that these concepts can be formulated as mixed-integer linear programming (MILP) problems and efficient algorithms are presented for the determination of the above notions as well as for accessibility, structural controllability and observability. Several examples illustrate the concepts and the proposed approach.

ISSN:0020-7179    

DOI:10.1080/00207179008934055

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The left characteristic matrix equation (lcme), introduced in earlier work, has proved to be a useful tool in the development of a feedback stabilization theory for delay systems. In this work, the dual notion of the right characteristic matrix equation (rcme) of a delay system is introduced via the state feedback stabilization of a dual system. As an application of the rcme, an observer theory is developed for spectrally detectable delay systems using well-established finite dimensional system tools. Employing the resulting observer to generate the state feedback controls of the above-mentioned stabilization theory, it is shown that the separation property holds. This work thus renders the state feedback stabilization theory implementable by input-output data.

ISSN:0020-7179    

DOI:10.1080/00207179008934056

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor