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:

2010 (Volume 20)
Number 1
1. State estimate based control design using the unified algebraic approach
2. Nonlinear response of a harmonically driven oscillator in magnetic field
3. Robust output predictive sequential controller design
4. Evaluation of the Shunt Active Power Filter apparent power ratio using particle swarm optimization
5. The influence of the piezoelements placement on the active vibration damping of smart truss
6. Lyapunov functional for a linear system with two delays both retarded and neutral type
7. Suppression of vibration with optimal actuators and sensors placement


State estimate based control design using the unified algebraic approachDownload full PDF article
A. Filasova
(Department of Cybernetics and Artificial Intelligence, Technical University of Kosice, Slovak Republic)
D. Krokavec
(Department of Cybernetics and Artificial Intelligence, Technical University of Kosice, Slovak Republic)

The LMI based method for the control with the state estimate, subject to the input variable constraints in the state feedback control of the linear MIMO systems, is presented in the paper. For this problem are obtained the state feedback as well as the estimator gain matrices that capture the required stability by solving the linear matrix inequalities formulated in the sense of the unified algebraic approach. The method is particularly effective when the input variable constraints and the system output are of interest.

keywords: state feedback, linear estimation, linear matrix inequalities, constrains

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Nonlinear response of a harmonically driven oscillator in magnetic fieldDownload full PDF article
P. Przybyłowicz
(nstitute of Construction Machinery Engineering, Warsaw University of Technology, Poland)
T. Szmidt
(nstitute of Construction Machinery Engineering, Warsaw University of Technology, Poland)

The paper presents analysis of nonlinear response of a classical mechanical oscillator placed within a magnetic field and driven by a harmonic force. With an appropriate choice of control parameters, the system vibrates chaotically between different equilibrium positions. To prove this result, Lyapunov exponents have been calculated using the algorithm proposed by Rangarajan G., Habib S. and Ryne R.: Physical Review Letters, vol. 80, (1998). Moreover, the appropriate time series, phase portrait, Poincar'e cross-section and power spectrum are given to support the conclusion.

keywords: nonlinear vibrations, oscillator, chaos, stability, magnetic damping

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Robust output predictive sequential controller designDownload full PDF article
V. Vesely
(Faculty of Electrical Engineering and IT, URPI, Slovak University of Technology, Bratislava, Slovak Republic)
D. Rosinova
(Faculty of Electrical Engineering and IT, URPI, Slovak University of Technology, Bratislava, Slovak Republic)

The paper addresses design problem of a robust parameter dependent quadratically stabilizing  output/state feedback model predictive control for linear polytopic systems without constraints using original equential approach.  The design procedure ensures stability, robustness properties  and guaranteed cost for the closed-loop uncertain system.

keywords: model predictive control, robust control, parameter dependent quadratic stability, Lyapunov function, polytopic system, sequential approach

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Evaluation of the Shunt Active Power Filter apparent power ratio using particle swarm optimizationDownload full PDF article
A. Kouzou
(Electrical Department, University Centre of Djelfa, Algeria)
M.O. Mahmoudi
(LCP, National Polytechnic School, Algiers, Algeria)
M.S. Boucherit
(LCP, National Polytechnic School, Algiers, Algeria)

The main objective of this present paper is the study of the Shunt Active Power Filter (APF) compensations capability for different perturbations in AC power system such as current unbalance, phase shift current and undesired harmonics generated by nonlinear load and/or by the power system voltage. This capability is determined by the maximum rate of the apparent power that can be delivered. This study is based on the definition of the effective apparent power as defined in IEEE 1459-2000 which was proved to be the suitable amount to be concerned in the design process of different devices.

keywords: effective apparent power, shunt active power filter, particle swarm optimization, harmonics, unbalanced voltages, unbalanced load

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The influence of the piezoelements placement on the active vibration damping of smart trussDownload full PDF article
Z. Gosiewski
(Faculty of Mechanical Engineering, Department of Automatics and Robotics, Technical University of Białystok, Poland)
A.P. Koszewnik
(Faculty of Mechanical Engineering, Department of Automatics and Robotics, Technical University of Białystok, Poland)

Vibrations control in truss structures reaches a great practical interest, mainly in modern structures of huge space vehicles and aircrafts. Two demands essences are required in design of such structures. The first is the excellent dynamic behavior, in order to guarantee the stability of the structure and high precision pointing. The second is the necessity to obtain light structures, in order to reduce the cost. However, these two requirements are often contradictory, because light structures have low degrees of internal damping, which hinders the accuracy requirements.

These difficulties can be overcome by applying recently developed advanced materials, as for instance piezoelectric materials. Several researchers have proved that piezoelectric material can effectively counteract the vibrations. Appropriate assurance active damping of these vibrations can be achieved by optimal location of the piezo elements in the structure.

keywords: vibrations, piezo-stack actuator, active truss, modal mass, modal stiffness

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Lyapunov functional for a linear system with two delays both retarded and neutral typeDownload full PDF article
J.Duda
(Institute of Automatic Control, AGH University of Science and Technology, Krakow, Poland)

The paper presents a method of determining of the Lyapunov quadratic functional for linear time-invariant system with two delays both retarded and neutral type. The Lyapunov functional is constructed for a given its time derivative which is calculated on the trajectory of the system with two delays both retarded and neutral type. The presented method gives analytical formulas for the coefficients of the Lyapunov functional.

keywords: Lyapunov functional, time delay system, neutral system, LTI system

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Suppression of vibration with optimal actuators and sensors placementDownload full PDF article
L. Starek, D. Starek, P. Solek
(Institute of Applied Mechanics and Mechatronics, Slovak University of Technology, Bratislava, Slovak Rep.)
A. Starekova
(Institute of Mathematics, Slovak University of Technology, Bratislava, Slovak Rep.)

It is proposed to place the actuators to maximize the mean value of energy transmitted from or dissipated by the actuators, while the sensor location should maximize the mean square value of system output, which also maximizes the signal-to-noise ratio. By using explicit expressions for controllability and observability grammians as well as modal energies, it is shown that the approaches based on the system responses to transient and persistent disturbances are closely related, and are equivalent for structures which damping is small and the natural frequencies of which are well spaced. The method of actuator and sensor optimal location via grammians was proposed and compared it with results given by the method of matrix norms.

keywords: optimal location, vibration suppression, actuator, sensor

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