Wyniki wyszukiwania - BazTech

1

Extended state observer based robust feedback linearization control applied to an industrial CSTR

Medjebouri Ali

Journal of Automation Mobile Robotics and Intelligent Systems

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2023

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Vol. 17, No. 4

68--78

EN

In the chemical and petrochemical industry, the Continuous Stirred Tank Reactors (CSTR) are, without doubt, one of the most popular processes. From a control point of view, the mathematical model describing the temporal evolution of the CSTR has a strongly nonlinear cross-coupled character. Moreover, modeling errors such as external disturbances, neglected dynamics, and parameter variations or uncertainties make its control task a very difficult challenge. Even though this problem has been the subject of a wide number of control strategies, this article attempts to propose a viable, robust, nonlinear decoupling control scheme. The idea behind the proposed approach lies in the design of two nested control loops. The inner loop is responsible for the compensation of the nominal model nonlinear cross-coupled terms via static nonlinear feedback; whereas the outer loop, designed around an Extended State Observer (ESO) of which the additional state gathers the global effect of modeling errors, is charged to instantaneously estimate, and then to compensate the ESO extended state. This way, the CSTR complex dynamics are reduced to a series of decoupled linear subsystems easily controllable using a simple Proportional-Integral (PI) linear control to ensure the robust pursuit of reference signals respecting the desired performance. The presented control validation was performed numerically by an objective comparison to a classical PID controller. The obtained results clearly show the viability and the effectiveness of the proposed control strategy for dealing with such nonlinear, strongly cross-coupled plants subject to a wide range of disturbances despite the precision of their described mathematical model.

2

Impact of Using an Inerter on the Performance of Vehicle Active Suspension

Alshabatat Nabeel, Shaqarin Tamir

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 3

331--339

EN

This paper investigates the effect of employing an inerter on the performance of active suspension systems. A quarter-car model with cubic-nonlinear spring is considered. The inerter is installed in parallel with the primary suspension spring and damper. First, feedback linearization (FBL) is used to linearize the mathematical model. Then the linear quadratic regulator (LQR) is adopted to control the suspension system. The proposed design is ride comfort-oriented and considers structural constraints. Numerical simulations are executed for passive systems with different values of inertance. Results show that employing an inerter to the passive suspension can improve the ride comfort performance by more than 32%. Employing an inerter to active suspension systems can also improve the ride comfort and reduce actuator force significantly. The actuator force can be reduced by 25%. However, the results also show that the uncaring selection of the inerter can dramatically degrade the performance of the suspension system.

3

Control design of an UAV–Q based on feedback linearization and optimum modulus methods

Chuyen Tran Duc, Huy Hoang Van, Nguyen Tung Lam

Annals of Computer Science and Information Systems

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2021

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Vol. 27

17--22

EN

In the paper, we present the formulation of quadrotor control loops that are based on a decomposition into a cascade structure and the use of feedback linearization and optimum modulus methods to determine controller parameters. The dynamic model used in this paper considers the dynamics of the propeller rotor drive systems. The propeller rotor drive systems are considered as a linear actuated system. After the synthesizing of the controllers is completed, the system is simulated in MATLAB/Simulink. The results from this work can be useful for the development of autonomous algorithms for UAV-Q (Unmanned Aerial Vehicle Quadrotor). The research results serve as the basis for control algorithms development for other similar systems.

4

Feedback linearization of an active magnetic bearing system operated with a zero-bias flux

Mystkowski A., Kaparin V., Kotta Ü., Pawluszewicz E., Tõnso M.

International Journal of Applied Mathematics and Computer Science

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2017

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Vol. 27, no. 3

539--548

EN

Input-output linearization by state feedback is applied to a flux-controlled active magnetic bearing (AMB) system, operated in the zero-bias mode. Two models of the AMB system are employed. The first one is described by the third-order dynamics with a flux-dependent voltage switching scheme, whereas the second one is the fourth-order system, called self-sensing AMB, since it does not require the measurement of the rotor position. In the case of that system we had to find the flat outputs to guarantee its stability. The proposed control schemes are verified by means of numerical simulations performed within the Matlab environment.

5

Feedback linearization based nonlinear control of magnetic levitation system

Jaroszyński J., Zietkiewicz J.

Studia z Automatyki i Informatyki

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2016

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T. 41

35--46

EN

Control of unstable nonlinear system is challenging - for the method relying on objective function this function may not be convex. Feedback linearization derives exact linear model that imitates the dynamics of nonlinear model. In this paper for feedback linearized system linear quadratic control is applied. The method is simulated on magnetic levitation system. Simulation shows that the control assures good performance.

PL

Sterowanie nieliniowymi, niestabilnymi obiektami jest wymagające - jeśli metoda opiera się na funkcji celu, funkcja ta może być niewypukła. Linearyzacja przez sprzężenie zwrotne zapewnia dokładny liniowy model odwzorowujący dynamikę modelu nieliniowego. W artykule do zlinearyzowanego systemu zastosowane jest sterowanie liniowo - kwadratowe. Metoda jest przetestowana symulacyjnie na układzie magnetycznej lewitacji. Otrzymane symulacje pokazują dobrą jakość takiego rozwiązania.

6

Linear quadratic control with feedback-linearized models

Ziętkiewicz J.

Studia z Automatyki i Informatyki

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2015

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T. 40

37--49

EN

The paper considers two questions. Firstly, to adjudicate whether the feedback linearization is actually better for control than the plain Jacobian linearization. This issue is settled by using linear quadratic control strategy for above-mentioned linear models. The second question results from the efforts of joining feedback linearization and linear quadratic control: how should the weights of the cost function be calculated for the model obtained from feedback linearization, when the variables are not direct physical values? This paper shows a method of adjusting those weights, which is based on the weights of the quadratic cost functions for Jacobian-linearized model. The two questions are therefore interrelated because the method of adjusting weights gives us similar control strategies for the two different linear models. This is used for the comparison of the two linearization methods. The obtained results show that combining linear quadratic control with feedback linearization yields the performance index usually better, or at least not worse, than when combining it with Jacobian linearization. The former combination can be used successfully for many nonlinear systems.

PL

W pracy rozważane są dwie kwestie. Pierwsza z nich dotyczy sprawdzenia, czy model otrzymany za pomocą linearyzacji przez sprzężenie zwrotne będzie lepiej sprawdzał się w warunkach regulacji niż model otrzymany za pomocą przybliżonej linearyzacji w punkcie pracy. Druga kwestia wynika z próby połączenia modelu otrzymanego przez linearyzację przez sprzężenie zwrotne ze sterowaniem liniowo kwadratowym: jak powinny być dobierane wagi w funkcji kosztu w tym przypadku, kiedy zmienne w tej funkcji nie są bezpośrednio wielkościami fizycznymi? W artykule pokazano metodę pozwalającą na dobór wspomnianych wag z użyciem funkcji kosztu wybranej dla modelu uzyskanego z linearyzacji w punkcie. Powyższe kwestie wiążą się ze sobą, ponieważ taki dobór wag pozwala uzyskać podobną strategię sterowania przy różnych modelach liniowych, co pozwala porównać wykorzystanie tych dwóch modeli w algorytmie sterowania. Otrzymane wyniki pokazują, że połączenie metody linearyzacji przez sprzężenie zwrotne z regulatorem liniowo kwadratowym pozwala uzyskać w większości przypadków lepszy wskaźnik jakości niż przy wykorzystaniu modelu liniowego otrzymanego na podstawie przybliżonej linearyzacji w punkcie. Pierwsze z podejść może być z powodzeniem stosowane dla wielu nieliniowych obiektów.

7

The design of ship autopilot by applying observer – based feedback linearization

Zwierzewicz Z.

Polish Maritime Research

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2015

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nr 1

16--21

EN

The paper considers the problem of ship autopilot design based on Bech’s model of the vessel. Since the model is highly nonlinear and some of the state vector coordinates are unavailable, the control system synthesis is performed by means of an output feedback linearization method combined with a nonlinear observer. The asymptotic stability of the overall system has been proven, including the asymptotic stability of the system internal dynamics. The performed simulations of the ship course-changing process have confirmed a high performance of the proposed controller. It has been emphasized that for its practical usability the system robustification is necessary.

8

On Levitation Controller Design for Maglev Vehicles Considering Different Track Curves

Liu H., Zhang X., Dai C.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

59--63

EN

The model of maglev vehicle varies when the vehicle is on different track curves, which will affect the suspension performance and limit the vehicle’s speed passing curves. The problem of model change can be settled when the nonlinear control method applied to the levitation system, in the control method the accelerometer output and second derivative of gap are applied. The adverse effect brought by the track curve change can be eliminated and the maglev suspension performance is invariable. The validity of the method is proved through simulation results.

PL

Model pojazdu pociągu maglev zmienia się dla różnych krzywizn toru, co może wpłynąć na działanie zawieszenia i ogranicza szybkość pojazdu na krzywiźnie drogi. Problemu zmiany modelu można uniknąć przez zastosowanie, do systemu lewitacjj, nieliniowej metody sterowania oraz wykorzystania , w metodzie sterowania, wyjściowych danych akceleratora i różniczki drugiego rzędu względem szczeliny. W ten sposób można wyeliminować niekorzystny efekt wniesiony przez zmianę krzywizny toru i ustabilizować działanie zawieszenia. Symulacja dowodzi słuszności zastosowanej metody.

9

Input-Output Linearization and Predictive Current Controller for Offshore Wind Farm VSC-HVDC

Li S., Wang Z., Wang G.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1a

230--234

EN

In this paper, a nonlinear controller for VSC-HVDC transmission system is proposed. The feedback linearization based nonlinear differential-geometric techniques is used to cancel nonlinearities and decouple the input control variables. A predictive current control (PCC) method is also proposed. It can predict the current reference for the next sampling instant rapidly and accurately. Comprehensive time-domain computer simulations within MATLAB/Simulink have been carried out and the results show the feasibility and effectiveness of the proposed control scheme.

PL

W artykule przedstawiono algorytm sterowania nieliniowego dla system przesyłu energii VSC-HVDC. W celu odprzężenia sterowanych zmiennych i eliminacji nieliniowości, zastosowano technikę nieliniowej geometrii-różniczkowej do linearyzacji sprzężenia zwrotnego. Zaproponowano także sterowanie predykcyjne prądu. Wykonane badania symulacyjne w programie Matlab/Simulink potwierdziły skuteczność algorytmu sterowania.

10

On the ship course-keeping control system design by using robust feedback linearization

Zwierzewicz Z.

Polish Maritime Research

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2013

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nr 1

70--76

EN

In the paper the problem of ship autopilot design based on feedback linearization method combined with the robust control approach, is considered. At first the nonlinear ship model (of Norrbin type) is linearized with the use of the simple system nonlinearity cancellation. Next, bearing in mind that exact values of the model parameters are not known, the ensuing inaccuracies are taken as disturbances acting on the system. Thereby is obtained a linear system with an extra term representing the uncertainty which can be treated by using robust, H∞optimal control techniques. The performed simulations of ship course-changing process confirmed a high performance of the proposed controller despite the assumed significant errors of its parameters.

11

Sterowanie manipulatorem o dwóch stopniach swobody z użyciem linearyzacji przez sprzężenie zwrotne

Ziętkiewicz J.

Studia z Automatyki i Informatyki

|

2009

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T. 34

95-104

PL

Celem pracy było zaprojektowanie układu regulacji do sterowania położeniem chwytaka manipulatora planarnego o dwóch ramionach. Do projektowania układu użyto linearyzacji przez sprzężenie zwrotne, natomiast sterowanie zrealizowano za pomocą algorytmu PD.

EN

The aim of the work was to design an application used for control of a two link manipulator. In order to simplify calculations feedback linearization has been adapted. System has been controlled by using PD algorithm with appropriate parameters.

12

Forced dynamics speed control of the drive with linear PMSM

Vavrúš V., Pospíšil M., Szychta E., Luft M.

Logistyka

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2009

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nr 6

CD-CD

EN

Forced dynamics control of the drive with linear permanent magnet synchronous motor is presented and verified. This, a relatively new control method offers an accurate realisation of a dynamic speed response with prescribed acceleration, which can be selected for given transport application by the user. In addition to this, vector control condition, which requires right angle between the stator current vector and moving part flux vector, is maintained as it is in conventional drives. To achieve prescribed speed response of moving part, the derived control law requires estimation of an external force, which is obtained from the set of two observers. The observer of moving part speed, which works in pseudo-sliding mode, is completed with the second one, having filtering effect to eliminate chattering of the previous one. The proposed control algorithms with precisely defined acceleration, one of which is suitable for traction application, are verified by simulations and experimentally. Preliminary experiments confirmed that the moving part speed response is capable to follow prescribed smooth acceleration fairly closely.

PL

W artykule jest prezentowany i weryfikowany układ sterowania dynamicznego napędu z liniowym synchronicznym silnikiem z magnesami trwałymi. Ta stosunkowo nowa metoda sterowania powoduje dokładną realizację dynamicznie zadanej prędkości z zadanym może być wybrana przez użytkownika dla danego zastosowania w transporcie. Warunek sterowania wektorowego, który wymaga prawidłowego kąta pomiędzy wektorem prądu stojana a wektorem strumienia części ruchomej jest utrzymany, jak w tradycyjnych napędach. Aby osiągnąć zadaną odpowiedź prędkości części ruchomej, przedstawione prawo sterowania wymaga estymacji zewnętrznego wymuszenia otrzymywanego poprzez układ dwóch obserwatorów. Obserwator prędkości części ruchomej, który pracuje w trybie 'pseudosliding' jest uzupełniony przez drugi, mający właściwość filtracji eliminującej zakłócenia wprowadzane przez pierwszy obserwator. Proponowane algorytmy sterowania z dokładnie zdefiniowanym przyśpieszeniem, mogą być użyteczne w zastosowaniach trakcyjnych. Są one zweryfikowane poprzez badania symulacyjne i eksperymentalne. Wstępne wyniki badań eksperymentalnych potwierdziły, że odpowiedź części ruchomej jest zdolna dość dokładnie nadążyć za przyśpieszeniem.

13

Input constraints handling in an MPC/feedback linearization scheme

Deng J., Becerra V. M., Stobart R.

International Journal of Applied Mathematics and Computer Science

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2009

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Vol. 19, no 2

219-232

EN

The combination of model predictive control based on linear models (MPC) with feedback linearization (FL) has attracted interest for a number of years, giving rise to MPC+FL control schemes. An important advantage of such schemes is that feedback linearizable plants can be controlled with a linear predictive controller with a fixed model. Handling input constraints within such schemes is difficult since simple bound contraints on the input become state dependent because of the nonlinear transformation introduced by feedback linearization. This paper introduces a technique for handling input constraints within a real timeMPC/FL scheme, where the plant model employed is a class of dynamic neural networks. The technique is based on a simple affine transformation of the feasible area. A simulated case study is presented to illustrate the use and benefits of the technique.

14

Nonlinear robust output feedback control of submersibles via modeling error compensation

Nambisan P. R., Singh S. N.

Systems Science

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2007

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Vol. 33, no 4

27-35

EN

This paper treats the design of a nonlinear robust dive-plane control system for multivariable submersibles equipped with bow and stern hydroplanes. It is assumed that the vehicle's parameters and the hydrodynamic coefficients are not known, and that disturbance forces due to the sea wave are acting on the vehicle. For the design, the depth and pitch angle are chosen as output variables. Using nonlinear input-output (pitch angle and depth) map inversion, a robust nonlinear output feedback control law for the trajectory control of the pitch angle and depth id derived. For synthesizing the robust inverse control law, the unknown functions and unmeasurable variables are estimated using a high-gain observer. It is shown that in the closed-loop system, the asymptotic tracking of the depth and pitch angle trajectories is accomplished. Simulation results are presented which show precise dive-plane maneuvers in spite of uncertainty in the system parameters and disturbance forces due to the sea waves.

15

Fuzzy feedback linearizing controller and its equivalence with the fuzzy nonlinear internal model control structure

Boukezzoula R., Galichet S., Foulloy L.

International Journal of Applied Mathematics and Computer Science

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2007

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Vol. 17, no 2

233-248

EN

This paper examines the inverse control problem of nonlinear systems with stable dynamics using a fuzzy modeling approach. Indeed, based on the ability of fuzzy systems to approximate any nonlinear mapping, the nonlinear system is represented by a Takagi-Sugeno (TS) fuzzy system, which is then inverted for designing a fuzzy controller. As an application of the proposed inverse control methodology, two popular control structures, namely, feedback linearization and Nonlinear Internal Model Control (NIMC) are investigated. Moreover, the paper points out that, under some conditions, both of the control structures are equivalent and naturally implement a Smith predictor in the presence of time delays.

16

New approach to linguistic fuzzy modeling of induction motor fed by PWM voltage source inverter

Barazane L., Krishan M. M., Khwaldeh A., Sicard P.

Archives of Control Sciences

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2007

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Vol. 17, no. 2

209-235

EN

In this paper, a new approach of linguistic fuzzy modeling proposed by Ben-Ghalia et al. is applied to induction motor. Thus, a classical model is first given together with the most used asynchronous motor control strategy, which is the pole assignment. After more, in order to minimize the dependence of the system to parameter variations and external perturbations, and reduce the number of variable states, a new model of the original system is proposed. This model is too simple and is suitable to cognitive approach such as fuzzy modeling. Then, fuzzy modeling of an uncertain system using the approach of Ben-Ghalia et al. to reduce the effects of imperfections of the classical modeling are introduced. In addition, their applications in the fuzzy sliding mode control of the asynchronous motor are presented. Finally, Simulation results reveal some very interesting features and show that the proposed fuzzy model has great potential for use as an alternative to the approximation of the conventional model of induction motor taking into account the effect of system model uncertainties and gives a good performances in sliding mode control.