Wyniki wyszukiwania - BazTech

1

Variable-structure repetitive control for discrete-time linear systems with multiple-period exogenous signals

Kurniawan Edi, Harno Hendra G., Wijonarko Sensus, Widiyatmoko Bambang, Bayuwati Dwi, Purwowibowo Purwowibowo, Maftukhah Tatik

International Journal of Applied Mathematics and Computer Science

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2020

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Vol. 30, no. 2

207--218

EN

A new method to construct a discrete-time variable-structure repetitive controller for a class of linear systems perturbed by multiple-period exogenous signals is presented. The proposed control scheme combines the features of the discrete-time multiple-period repetitive control (MP-RC) and variable-structure control (VSC) techniques. The MP-RC part is assigned to simultaneously track and reject periodic signals consisting of multiple uncorrelated fundamental frequencies. The VSC part is then integrated to provide a fast transient response and robustness against plant parameter variations. Stability and robustness analyses are also elaborated to ensure that the resulting closed-loop system satisfies the desired control objectives. Moreover, it is shown through an example that the repetitive control system constructed using the proposed control method can effectively track a sinusoidal reference signal despite the presence of a multiple-period disturbance.

2

Design of an adaptive fuzzy variable structure compensator for the nonholonomic mobile robot in trajectory tracking task

Begnini M., Bertol W., Martins N. A.

Control and Cybernetics

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2018

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Vol. 47, no. 3

239--275

EN

A robust adaptive kinematic control strategy, based on the methodology of variable structure control is considered in this paper. Because the dynamics of mobile robots is subject to uncertainties and disturbances, a fuzzy compensator is adopted to estimate them. In order to minimize the tracking errors and to attenuate the chattering phenomenon, an adaptation law for the fuzzy compensator is obtained by Lyapunov stability theory so as to asymptotically stabilize the control system as well as guarantee the convergence of the tracking errors. In terms of comparison with the boundary layer variable structure controller, simulations and experiments verify the feasibility and eﬀectiveness of the proposed kinematic control strategy for the nonholonomic mobile robots under the incidence of uncertainties and disturbances.

3

A novel method for the design of switching surfaces for discretized MIMO nonlinear systems

Luis-Delgado J. D., Al-Hadithi B. M., Jiménez A.

International Journal of Applied Mathematics and Computer Science

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2017

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Vol. 27, no. 1

5--17

EN

Designing variable structure control with sliding mode (VSC-SM) control schemes needs a switching function or a sliding surface which guarantees the global stability of the closed-loop system. Despite the fact that a wide range of design approaches has been proposed for solving this mathematical problem, the number of proposed methodologies for nonlinear systems is not very extensive, especially for discrete time nonlinear MIMO systems, and most of them require some coordinate system transformation. Therefore, it is not an easy task to find a design scheme that can be applied to discrete time nonlinear MIMO systems. The proposed methodology introduces a mathematical tool: a switching surface equation for a class of MIMO nonlinear systems through an explicit equation without any coordinate transformation. This equation makes use of an implicit linearizing process via the Taylor expansion that allows the use of linear procedures for the design of switching surfaces and the forward Euler method to obtain a discrete time dynamics representation. An illustrative example is included to show the advantages of the proposed design methodology.

4

Trajectory tracking of a wheeled mobile robot with uncertainties and disturbances: proposed adaptive neural control

Martins N. A., Alencar M., Lombardi W. C., Bertol D. W., Pieri E. R., Filho H. F.

Control and Cybernetics

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2015

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Vol. 44, no. 1

47--98

EN

This paper analyses a trajectory tracking control problem for a wheeled mobile robot, Rusing integration of a kinematic neural controller (KNC) and a torque neural controller (TNC), in which both the kinematic and dynamic models contain uncertainties and disturbances. The proposed adaptive neural controller (PANC) is composed of the KNC and the TNC and is designed with use of a modeling technique of Gaussian radial basis function neural networks (RBFNNs). The KNC is a variable structure controller, based on the sliding mode theory and is applied to compensate for the disturbances of the wheeled mobile robot kinematics. The TNC is an inertia-based controller composed of a dynamic neural controller (DNC) and a robust neural compensator (RNC) applied to compensate for the wheeled mobile robot dynamics, bounded unknown disturbances, and neural network modeling errors. To minimize the problems found in practical implementations of the classical variable structure controllers (VSC) and sliding mode controllers (SMC), and to eliminate the chattering phenomenon, the nonlinear and continuous KNC and RNC of the TNC are applied in lieu of the discontinuous components of the control signals that are present in classical forms. Additionally, the PANC neither requires the knowledge of the wheeled mobile robot kinematics and dynamics nor the timeconsuming training process. Stability analysis, convergence of the tracking errors to zero, and the learning algorithms for the weights are guaranteed based on the Lyapunov method. Simulation results are provided to demonstrate the eﬀectiveness of the proposed approach.

5

Sterowanie ślizgowe - odporna metoda regulacji obiektów dynamicznych

Bartoszewicz A.

Przegląd Elektrotechniczny

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2009

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R. 85, nr 9

24-29

PL

Przedstawiony niżej tekst - w przystępny sposób - opisuje najważniejsze zagadnienia sterowania o zmiennej strukturze z ruchem ślizgowym. Przedstawia podstawowe pojęcia dotyczące tej problematyki, wskazuje istotne zalety omawianej metody regulacji oraz wzmiankuje najbardziej aktualne problemy badawcze w tym zakresie.

EN

This paper presents - in a tutorial manner - principles of variable structure control systems with sliding modes. It presents basic notions relevant to the field of variable structure systems, shows principal advantages of the sliding mode control and makes an attempt to point out some current research trends in the field.

6

Time-varying switching planes in SMC of third order dynamic system

Nowacka-Leverton A.

Zeszyty Naukowe. Elektryka / Politechnika Łódzka

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2008

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z. 115

79-86

EN

In this paper an algorithm of a moving switching plane selection for sliding mode control (SMC) of the third order system subject to velocity, acceleration and input signal constraints is proposed. The plane is designed in such a way that initially it passes through the system representative point in the error state space and then it moves with a constant velocity to the origin of the space. Having reached the origin the plane stops moving and remains fixed. The plane parameters are chosen to minimize the integral absolute error (IAE) subject to velocity, acceleration and input signal constraints. Moreover, the system is insensitive to the external disturbance and the model uncertainty from the very beginning of the control action, and monotonic error convergence to zero is achieved.

PL

W pracy rozważano zagadnienie projektowania układów ślizgowego sterowania ciągłymi nieliniowymi i niestacjonarnymi- obiektami dynamicznymi trzeciego rzędu. Zaproponowano zastosowanie do tego celu ruchomej płaszczyzny przełączeń o stałym kącie nachylenia, która początkowo ze stałą prędkością porusza się w przestrzeni fazowej. Po osiągnięciu początku układu współrzędnych, rozważana płaszczyzna zatrzymuje się i dalej pozostaje nieruchoma. Płaszczyzna jest projektowana tak, aby w chwili początkowej, należał do niej punkt opisujący dynamikę obiektu. Wykorzystanie takiej płaszczyzny przełączeń zapewnia niewrażliwość układu na zakłócenia zewnętrze i niedokładności modelu od samego początku trwania procesu regulacji. Parametry tej płaszczyzny wybierane są tak, aby uzyskać dobre właściwości dynamiczne układu, przy spełnionych ograniczeniach sygnału sterującego, przyspieszenia i prędkości obiektu regulacji.

7

Non-linear excitation and governor control: a comparison of control schemes.

Iyer A.

Systems Science

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2000

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Vol. 26, nr 2

55-68

EN

Modem microprocessor capabilities permit the control designer to consider using relatively complicated nonlinear control algorithms, which would have been considered impractical in the past. In the paper inverse control and variable structure control are applied to the design of excitation and governor controllers using state variable feedback. The paper presents the results of a study of the two non-linear techniques for the design of excitation and governor controllers for a multi-machine power system. Control laws for rotor angle and field flux are derived. The closed loop system is shown to be asymptotically stable. The system can be transferred to a new operating condition corresponding to any desired terminal voltage V/sub t/ and tie-line power P/sub tie/.