摘要:

In known set of necessary and sufficient conditions for a linear system to be aperiodic, certain determinants are required to be positive. In the present paper these determinants are represented as sums of products of squares of root-pair-differences. The historical background of this result in nineteenth-century algebra is explored. Criteria are also obtained for roots to be all real without being necessarily simple.

ISSN:0020-7179    

DOI:10.1080/00207178808906122

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A linear, shift-invariant discrete system exhibiting two-time-scale (slow and fast) character is addressed. An iterative algorithm based on linear programming for the computation of time-optimal control is presented by decoupling the original system into slow and fast subsystems. It is found that the computation time and storage capacity for the computation of time-optimal control of the slow and fast subsystems is less than that required for the original system. A numerical example is provided to illustrate the proposed algorithm.

ISSN:0020-7179    

DOI:10.1080/00207178808906123

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

In this paper an adaptive control is designed for deterministic systems on the basis of the projection algorithm so that the quadratic loss function approaches its minimum at a rate of n−ϵ, ϵ > 0 and the parameter estimate converges to its true value with a near exponential rate.

ISSN:0020-7179    

DOI:10.1080/00207178808906124

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This paper addresses the problem of the robustness of a Luenberger observer applied to a given large-scale system to obtain the state estimation from the viewpoint of decentralized observation. While the large-scale system suffers parametric perturbations, a robust stability criterion for decentralized state estimation and control is derived. If saturating actuators are employed to drive the large-scale system, a new stability criterion is also given for the stabilization of large-scale systems by decentralized Luenberger observer-based constrained control. Finally, the results from several simulations are provided for illustration.

ISSN:0020-7179    

DOI:10.1080/00207178808906125

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This paper is concerned with the stabilization or large-scale systems via an observer–controller compensator. The overall system is considered as a decentralized form containing many linear time-invariant multivariable subsystems. Using both theM-matrix property and analysis of the input-output stability, a new stability criterion for large-scale systems controlled by observer–controller compensators is derived. Finally, based on this stability criterion, a design algorithm is proposed for finding a stabilizing observer–controller compensator for large-scale systems.

ISSN:0020-7179    

DOI:10.1080/00207178808906126

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Achievement of specified performance tolerances despite plant parameter uncertainty is one of the main reasons for using feedback in control. The effect of sensor noise at the plant input is used as a measure of the resulting ‘cost of feedback’. This cost can be too high if only the plant output is available. Previous studies have shown how the cost can be greatly reduced if internal variables can also be used, even if all feedback loops must be returned only to the plant input. In plant-modification (PM) feedback, such loops are allowed to be returned also to internal plant variables, causing increase in plant signal levels needed to produce the specified system output. It is then necessary to specify the maximum increases allowed. In this paper, a complex five-loop PM system is illustrated to give more insight into PM system design. It is shown that the cost is then reduced significantly more than in the non-PM designs.

ISSN:0020-7179    

DOI:10.1080/00207178808906127

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The theory of optimal output feedback control is extended to a class of quadratic performance measures whose weighting matrices are functions of frequency. The incorporation of frequency-dependent weighting matrices allows one to emphasise or de-emphasise the importance of the variables being penalised over specific bands of frequencies. Optimization of the frequency-shaped performance measure yields optimal compensators that can be more meaningful for certain minimisation problems. Results are presented for different configurations of frequency-shaping feedback control. An example is presented to illustrate the usefulness of the design technique.

ISSN:0020-7179    

DOI:10.1080/00207178808906128

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This paper derives three discrete state variable representations for a continuous-time plant driven by a zero-order hold with a combination of instantaneous measurements and measurements prefiltered by a multi-input/multi-output moving average (MA) process. These representations allow the control system engineer to model plants of this type accurately in a form which permits him to use standard techniques to design digital feedback controllers for them. An example is presented which illustrates how to obtain the coefficient matrices in each representation. Guidelines are presented for choosing the best representation to use for any given plant of this type.

ISSN:0020-7179    

DOI:10.1080/00207178808906129

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

We describe a globally stable tracking controller for robot manipulators. The controller is an extension of Takegaki and Arimoto's position controller to the tracking case where a theorem of Matrosov is used to prove its stability. An attractive feature of this controller is its resemblance to the computed torque controller with the inertia matrix outside the position and velocity feedback loops. Thus, our controller is decomposed into an inner PD loop and an outer dynamic compensation loop. This structure allows the simple PD computations to be run at a higher speed than the dynamic compensation loop in digital implementations.

ISSN:0020-7179    

DOI:10.1080/00207178808906130

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The problem of the existence of positively invariant polyhedral sets for linear discrete-time dynamical systems is studied. In the first part of the paper, necessary and sufficient conditions for a given polyhedral set to be a positively invariant set of a linear system are obtained. Then, the spectral properties of systems possessing this kind of invariant set are established. Finally the class of systems possessing positively invariant polyhedral cones is studied.

ISSN:0020-7179    

DOI:10.1080/00207178808906131

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor