Last issue
2016 (vol. 26) - Number 4


Andrzej Ruszewski:

Practical and asymptotic stability of fractional discrete-time scalar systems described by a new model



D. Krokavec, A. Filasova, P. Liscinsky:

On fault tolerant control structures incorporating fault estimation



Sundarapandian Vaidyanathan:

Hyperchaos, adaptive control and synchronization of a novel 4-D  hyperchaotic system with two quadratic nonlinearities



H. Górecki, M. Zaczyk:

Analytic solutions of transcendental equations with application to automatics



F. Mnif:

Predictor-based stabilization for chained form systems with input time delay



S. Daniar, R. Aazami, M. Shiroei:

Multivariable predictive control considering time delay for load-frequency control in multi-area power systems



T. Kaczorek:

Analysis and comparison of the stability of discrete-time and continuous-time linear systems



M. Rachik, M. Lhous:

An observer-based control of linear systems with uncertain parameters



L. Malinski:

Identification of stable elementary bilinear time-series model



V.V. Huynh:

New observer-based control design for mismatched uncertain systems with time-delay




ACS Abstract:

2009 (Volume 19)
Number 3
1. Controllers of the boost DC-DC converter accounting its minimum- and nonminimum-phase nature
2. LQ optimal and reaching law based design of sliding mode supply policy for inventory management systems
3. Optimal distributed control problems of retarded parabolic systems
4. Pointwise completeness and pointwise degeneracy of standard and positive fractional linear systems with state-feedbacks
5. Pole placement method for DC motor torque controller
6. Analytical and neuro-fuzzy modeling for fault detection and identification for nonlinear systems: application to robot manipulator


Controllers of the boost DC-DC converter accounting its minimum- and nonminimum-phase natureDownload full PDF article
R. Gessing
(Silesian University of Technology, Gliwice, Poland)

It is shown that the model of the boost DC-DC converter is minimum phase for operation on the left-hand side of the extremum of the steady state characteristic and nonminimum phase - on the right-hand side. For operation on the left-hand side a simple proportional controller is proposed which gives significantly better quality of control than many other controllers appearing in literature. However, it is noted that efficiency of the converter during operation on the left-hand side is smaller, therefore another original proposal of the controller based on nonlinear transformation and state feedback, designed for operation on the right-hand side, is proposed.

keywords: nonlinear systems, minimum/nonminimum phase systems, switched systems, PWM modulation, power electronics

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LQ optimal and reaching law based design of sliding mode supply policy for inventory management systemsDownload full PDF article
P. Ignaciuk, A. Bartoszewicz
(Technical University of Lodz, Lodz, Poland)

In this paper, the theory of discrete sliding-mode control is used to design new supply strategies for periodic-review inventory systems. The proposed strategies guarantee that demand is always entirely satisfied from the on-hand stock (yielding the maximum service level), and the warehouse capacity is not exceeded (what eliminates the cost associated with emergency storage). In contrast to the classical, stochastic approaches, in this paper, we focus on optimizing the inventory system dynamics. The parameters of the first control strategy are selected by minimizing a quadratic cost functional. Next, it is shown how the system dynamical performance can be improved by applying the concept of reaching law combined with dead-beat control. The stable, non-oscillatory behavior of the closed-loop system is demonstrated, and the properties of the designed controllers are discussed and strictly proved.

keywords: sliding-mode control, inventory control, discrete-time systems

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Optimal distributed control problems of retarded parabolic systemsDownload full PDF article
A. Kowalewski, A. Krakowiak
(AGH University of Science and Technology, Cracow, Poland)

Optimal distributed control problems of retarded parabolic systems are presented. Necessary and sufficient conditions of optimality are derived for the Neumann problem. A simple example of application is also presented.

keywords: distributed control, parabolic systems, time lags, linear quadratic problem, quadratic programming method

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Pointwise completeness and pointwise degeneracy of standard and positive fractional linear systems with state-feedbacksDownload full PDF article
T. Kaczorek
(Białystok Technical University, Białystok, Poland)

The pointwise completeness and pointwise degeneracy of standard and positive fractional linear discrete-time and continuous-time systems with state-feedbacks are addressed. It is shown that the pointwise completeness and pointwise degeneracy of the fractional positive continuous-time systems are invariant under the state and output feedbacks. Necessary and sufficient conditions are established for the existence of gain matrices of state-feedbacks for standard and positive linear systems such that the closed-loop systems are pointwise complete. Considerations are illustrated by numerical examples.

keywords: pointwise completeness, pointwise degeneracy, positive fractional linear system, feedback

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Pole placement method for DC motor torque controllerDownload full PDF article
G. Sieklucki
(AGH University of Science and Technology, Cracow, Poland)


The work describes the use of pole placement state-space method for parametric optimization of motor torque controller. Presented method is universal for any type of mathematical model in contrast to standard optimization (optimal shape or optimal modulus criterion). The general oscillatory element is analyzed. Mathematical models of separately excited and brushless DC motors are compared. Ready to use relationship for parametric optimization of motor torque controller is presented. The results of the simulation, in the environment Matlab-Simulink, of the closed-loop control system  are shown.

keywords:  electric drive, oscillatory element, motor torque controller, state-space, pole placement, normalized Bessel polynomials, separately excited DC motor (brush), brushless DC (BLDC) motor

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Analytical and neuro-fuzzy modeling for fault detection and identification for nonlinear systems: application to robot manipulatorDownload full PDF article
M.S. Lazeregue, H. Salhi
(Laboratoire Systemes Dept. Electonique, Universite Saad Dahlab, Soumaa, Blida, Algerie)
M. Tadjine
(Process Conrol Laboratory. Dept E.E. ENP, Alger, Algerie)

This work deals with modeling and fault detection and identification for  robot manipulator. We have used for a dynamical system a hybrid approach. The model is decomposed into two parts: first, a certain part modeled using classical analytical theory and it is preferable to be linear. Second, an uncertain part representing the nonlinearities neglected in the first part, which is modeled using neuro-fuzzy modeling. Both analytical redundancy and neuro-fuzzy modeling are used to improve robustness. The analytical redundancy is used to generate residuals for the fault detection and location procedure. The neuro-fuzzy modeling is used to model modeling errors and faults, which allows performing the robustness and the sensitivity. Thanks to neuro-fuzzy modeling the errors of modeling are compensated and the faults are well identified as it is shown through the results of simulation.

keywords: dynamical system, robot manipulator, neuro-fuzzy modeling, identification, error compensation, fault detection and identification

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