Wyniki wyszukiwania - BazTech

1

Dynamic sliding mode control based on a full-order observer: Underactuated electro-mechanical system regulation

Ordaz Patricio, Romero-Trejo Hugo, Cuvas Carlos, Sandre Omar

International Journal of Applied Mathematics and Computer Science

|

2024

|

Vol. 34, no. 1

29--43

EN

This paper concerns the synthesis of a nonlinear robust output controller based on a full-order observer for a class of uncertain disturbed systems. The proposed method guarantees that, in finite time, the system trajectories go inside a minimal neighborhood ultimately bounded. To this end, the attractive ellipsoid method is enhanced by applying the dynamic sliding mode control performance properties. Furthermore, in order to guarantee the stability of the trajectory around the trivial solution in the uniform-ultimately bounded sense, the feasibility of a specific matrix inequality problem is provided. With this feasible set of matrix inequalities, the separation principle of the controller/observer scheme considered also holds. To achieve a system performance improvement, a numerical algorithm based on the small size ultimate bound is presented. Finally, to illustrate the theoretical performance of the designed controller/observer, a numerical example dealing with the stabilization of a disturbed electromechanical system with uncertain and unmodeled dynamics is presented.

2

Zeroing the transfer matrix of the Roesser model of 2-D linear systems

Kaczorek Tadeusz

International Journal of Applied Mathematics and Computer Science

|

2023

|

Vol. 33, no. 4

513--519

EN

Controllability, observability and the transfer matrix of the discrete 2-D Roesser model are analyzed. It is shown that the controllability of the Roesser model is invariant under state feedbacks and the observability under output feedbacks. Sufficient conditions are established for the zeroing of the transfer matrix of the Roesser model.

3

Decentralized static output feedback controller design for linear interconnected systems

Fadhilah Helisyah Nur, Adzkiya Dieky, Arif Didik Khusnul, Zhai Guisheng, Mardlijah

International Journal of Applied Mathematics and Computer Science

|

2023

|

Vol. 33, no. 1

83--96

EN

Many interconnected systems in the real world, such as power systems and chemical processes, are often composed of subsystems. A decentralized controller is suitable for an interconnected system because of its more practical and accessible implementation. We use the homotopy method to compute a decentralized controller. Since the centralized controller constitutes the starting point for the method, its existence becomes very important. This paper introduces a non-singular matrix and a design parameter to generate a centralized controller. If the initial centralized controller fails, we can change the value of the design parameter to generate a new centralized controller. A sufficient condition for a decentralized controller is given as a bilinear matrix inequality with three matrix variables: a controller gain matrix and a pair of other matrix variables. Finally, we present numerical examples to validate the proposed decentralized controller design method.

4

Sterowany elektronicznie zasilacz z kompensacją temperatury do krzemowych fotopowielaczy (SiPM)

Matajek Tomasz, Mosorov Volodymyr

Przegląd Elektrotechniczny

|

2022

|

R. 98, nr 3

9--13

PL

W artykule przedstawiono zasadę działania, projekt i sposób obliczania elementów zasilacza do układów krzemowych fotopowielaczy (SiPM). Zasilacz jest skompensowany termicznie i wyposażony w analogowe wejście do regulacji napięcia wyjściowego. Podano i omówiono wyniki testów zbudowanego egzemplarza.

EN

This article presents the design, principle of operation and the method of calculating component values of power supply designed for silicon photomultipliers (SiPM). The power supply is thermally compensated and equipped with an analog input to regulate the output voltage. The results of the tests of the constructed prototype are presented and discussed.

5

Elektromechaniczne sprzężenie zwrotne dla niskotonowych głośników dynamicznych z kaskadowym połączeniem dwóch regulatorów PID

Łysek Tomasz

Elektronika : konstrukcje, technologie, zastosowania

|

2022

|

Vol. 63, Nr 10

24--32

PL

Artykuł zawiera projekt nowej metody redukcji zniekształceń nieliniowych w torze sygnałowym. Publikacja prezentuje opis elektronicznego systemu służącego do redukcji zniekształceń nieliniowych w niskotonowych głośnikach dynamicznych, schemat blokowy oraz schemat ideowy zmodyfikowanego systemu elektromechanicznego sprzężenia zwrotnego a także wyniki pomiarów zniekształceń nieliniowych. Projekt ten stanowi nowe podejście do projektowania tego typu układów. Układ wykorzystuje kaskadowe połączenie dwóch regulatorów PID. Układ podrzędny realizuje sprzężenie prądowe natomiast układ nadrzędny realizuje sprzężenie przyspieszeniowe. Prezentowany układ elektroniczny pozwala na znaczącą redukcję zniekształceń nieliniowych w zakresie najniższych częstotliwości pasma akustycznego. Wyniki pomiarów potwierdzają prawidłowe działanie metody redukcji zniekształceń zaproponowanej w tej publikacji.

EN

This article includes the development of a new method of reducing nonlinear distortion in the signal path. The paper presents the description of the electronic system used to reduce the nonlinear distortion in low-frequency dynamic loudspeakers, the block diagram and the schematic diagram of the modified motional feedback system and the measurement results of non-linear distortion. This project is a new approach to the design of this type of circuit. The system uses a cascade connection of two PID-controllers. The slave controller implements the current feedback, while the master controller implements the acceleration feedback. The presented electronic circuit allows for a significant reduction of nonlinear distortion at the lowest frequencies of the acoustic band. The measurement results confirmed the correctness of the nonlinear distortion reduction method proposed in this publication.

6

An approximate solution of the affine-quadratic control problem based on the concept of optimal damping

Veremey Evgeny I.

International Journal of Applied Mathematics and Computer Science

|

2021

|

Vol. 31, no. 1

5--15

EN

The paper is devoted to a particular case of the nonlinear and nonautonomous control law design problem based on the application of the optimization approach. Close attention is paid to the controlled plants, which are presented by affine-control mathematical models characterized by integral quadratic functionals. The proposed approach to controller design is based on the optimal damping concept firstly developed by V.I. Zubov in the early 1960s. A modern interpretation of this concept allows us to construct effective numerical procedures of control law synthesis initially oriented to practical implementation. The main contribution is the proposition of a new methodology for selecting the functional to be damped. The central idea is to perform parameterization of a set of admissible items for this functional. As a particular case, a new method of this parameterization has been developed, which can be used for constructing an approximate solution to the classical optimization problem. Applicability and effectiveness of the proposed approach are confirmed by a practical numerical example.

7

Gender differences of the improvement in balance control based on the real-time visual feedback system with smart wearable devices

Wang I-Lin, Wang Li-I, Xue Shi-Jie, Hu Rui, Jian Rong-Jiun, Ho Chun-Sheng

Acta of Bioengineering and Biomechanics

|

2021

|

Vol. 23, no. 1

163--171

EN

Purpose: The body maintains stability by integrating inputs from the central nervous system of vision, hearing, proprioception, and multiple senses. With the development of smart wearable devices, smart wearable devices can provide real-time center of pressure position-assisted balance control, which is beneficial to maintain physical balance. Methods: Forty healthy college students (20 male, 20 female) participated in this study, and the posture balance actions of left-leg stance non-visual feedback, left-leg stance visual feedback, right-leg stance non-visual feedback, and right-leg stance visual feedback were performed. Visual feedback provided smart insoles matching Podoon APP on a tablet computer with the COP position displayed by a dot as real-time visual feedback. Results: The experimental results show that the displacement, velocity, radius, and area of the COP decreased significantly in the left-leg stance visual feedback/right-leg stance visual feedback, the test compared the parameters in the left-leg stance non-visual feedback/right-leg stance nonvisual feedback (P < 0.05). Providing visual feedback through intelligent insoles can reduce the movement of the center of mass and maintain physical stability for healthy young people of different genders. In the one leg visual/non-visual in standing, the COP maximum anteroposterior displacement, COP anteroposterior velocity, COP radius, and COP area in women are significantly smaller than in men (P < 0.05). Women have better real-time balance control ability than men with smart insoles. Conclusions: The simple intelligent wearable assisted devices can immediately increase the control ability in static stance of men and women, and women have better real-time balance control ability than men.

8

Input reconstruction by feedback control for the Schlögl and FitzHugh–Nagumo equations

Maksimov Vyacheslav, Trlötzsch Fredi

International Journal of Applied Mathematics and Computer Science

|

2020

|

Vol. 30, no. 1

5--22

EN

Dynamical reconstruction of unknown time-varying controls from inexact measurements of the state function is investigated for a semilinear parabolic equation with memory. This system includes as particular cases the Schlögl model and the FitzHugh–Nagumo equations. A numerical method is suggested that is based on techniques of feedback control. An error analysis is performed. Numerical examples confirm the theoretical predictions.

9

An information based approach to stochastic control problems

Bania Piotr

International Journal of Applied Mathematics and Computer Science

|

2020

|

Vol. 30, no. 1

23--34

EN

An information based method for solving stochastic control problems with partial observation is proposed. First, information-theoretic lower bounds of the cost function are analysed. It is shown, under rather weak assumptions, that reduction in the expected cost with closed-loop control compared with the best open-loop strategy is upper bounded by a non-decreasing function of mutual information between control variables and the state trajectory. On the basis of this result, an information based control (IBC) method is developed. The main idea of IBC consists in replacing the original control task by a sequence of control problems that are relatively easy to solve and such that information about the system state is actively generated. Two examples of the IBC operation are given. It is shown that the method is able to find an optimal solution without using dynamic programming at least in these examples. Hence the computational complexity of IBC is substantially smaller than that of dynamic programming, which is the main advantage of the proposed method.

10

Land consolidation as one of the driving forces for socio-economic development of rural areas. Case study of the Małopolska Region

Dudzińska Małgorzata, Prus Barbara

Geomatics, Landmanagement and Landscape

|

2020

|

no. 1

7--21

EN

One of the benefits resulting from the implementation of land consolidation works should be the positive socio-economic change felt in rural areas. The aim of this paper is to examine the level of socio-economic development of rural municipalities of Małopolska Region, in which land consolidation projects were implemented in the years 2004–2013. The following were determined: the scope of implementation of land consolidation projects in municipalities of Małopolska Region, and the level of the socio-economic development of those municipalities. The study employed the following methods: analysis and synthesis of the literature, and the application of spatial-statistical approaches. The study determined that the values of the indicator expressing the dynamics of changes to the socio-economic development of municipalities were three times higher for the municipalities in which traditional land consolidation works were implemented as opposed to infrastructural ones. It was also observed that in the municipalities, in which traditional consolidation works were implemented, the level of socio-economic changes always took positive values, thus indicating the socio-economic development advantage compares to the situation in municipalities in which infrastructural consolidation projects were implemented.

11

Feedforward feedback iterative learning control method for the multilayer boundaries of oversaturated intersections based on the macroscopic fundamental diagram.

Lin Xiaohui, Xu Jianmin

Archives of Transport

|

2020

|

Vol. 53, iss. 1

67--87

EN

The feedback control based on the model and method of iterative learning control, which in turn is based on the macroscopic fundamental diagram (MFD), mostly belongs to the classification of single-layer boundary control method. However, the feedback control method has the problem of time delay. Therefore, a feed forward feedback iterative learning control (FFILC) method based on MFD of the multi-layer boundary of single-area oversaturated intersections is proposed. The FFILC method can improve the effectiveness of boundary control and avoid the time-delay problem of feedback control. Firstly, MFD theory is used to determine the MFD of the control area; the congestion zone and the transition zone of the control area are identified; and the two-layer boundary of the control area is determined. Then, the FFILC controllers are established at the two-layer boundary of the control area. When the control area enters into a congestion state, the control ratio of traffic flow in and out of the two-layer boundary is adjusted. The cumulative number of vehicles in the control area continues to approach the optimal cumulative number of vehicles, and it maintains high traffic efficiency with high flow rates. Finally, The actual road network is taken as the experimental area, and the road network simulation platform is built. The controller of the feedforward iterative learning control (FILC) is selected as the comparative controller and used to analyse the iterative effect of FFILC. Improvements in the use of traffic signal control indicators for the control area are analysed after the implementation of the FFILC method. Results show that the FFILC method considerably reduces the number of iterations, and it can effectively improve convergence speed and the use of traffic signal evaluation indicators for the control area.

12

Almost periodic synchronization of fuzzy cellular neural networks with time-varying delays via state-feedback and impulsive control

Li Yongkun, Wang Huimei, Meng Xiaofang

International Journal of Applied Mathematics and Computer Science

|

2019

|

Vol. 29, no. 2

337--349

EN

In this paper, we are concerned with drive-response synchronization for a class of fuzzy cellular neural networks with time varying delays. Based on the exponential dichotomy of linear differential equations, the Banach fixed point theorem and the differential inequality technique, we obtain the existence of almost periodic solutions of this class of networks. Then, we design a state feedback and an impulsive controller, and construct a suitable Lyapunov function to study the problem of global exponential almost periodic synchronization for the drive-response systems considered. At the end of the paper, we provide an example to verify the effectiveness of the theoretical results.

13

Network effects in online marketplaces: the case of Kiva

Mendelson Haim, Shen Yuanyuan

Annals of Computer Science and Information Systems

|

2019

|

Vol. 18

535--538

EN

Advanced information technologies have enabled the development of online marketplaces that connect businesses and people on a global scale. Much of the analysis of the adoption, growth and engagement on these marketplaces in the extant literature is based on the premise that they are characterized by network effects - a premise that has major implications for their deployment, implementation and management. In this paper we test this premise using data from Kiva, the world's largest online, peer-to-peer social lending marketplace. We find that while network effects are strong and significant during the early growth phase of the marketplace, they become weak or disappear once the marketplace stabilizes.

14

Discrete-continual strengthening of contacting structural elements: mathematical and numerical modeling

Marchenko A., Kravchenko S., Tkachuk M., Tkachuk M., Saverska M.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

|

2018

|

z. 2/116

143--153

EN

Discrete-continual hardening is proposed for contacting elements of machines. The method suggests that one part is hardened in a discrete manner while the other one is hardened continually over the entire surface. The resulting contact pair acquires positive qualities from each of the employed hardening techniques. Performance of the proposed technology is evaluated by means of stress analysis of the treated fragments. Unlike traditional hardening technologies the new one implements negative feedback mechanisms in the system "loading - contact interaction - friction - wear". This results in a positive integral effect which outperforms the individual contributions of each of the hardening technologies involved. It provides more favorable contact conditions in particular contact pressure distribution. This leads to decrease in wear, which in turn it prevents dramatic increase of the working loads. Consequently, the stabilization of investigated processes occurs. Enhancement of contact conditions of hardened bodies is demonstrated by structural analysis of a representative fragment of the studied system. The results of the numerical modeling confirm the technology design premises. The locally hardened zones do actually bear major loads. Nevertheless, friction and wear in the hardened zones are reduced due to the enhanced tribomechanical properties of the material compared to the remaining part of the body. Continual treating of the response part further amplifies this effect. In particular, metal materials like aluminum are covered by a thin layer of oxides formed by application of strong electric current in a special medium. The consolidated oxide phase form surface layers that perform structural role. Together with the discretely hardened surface of the response part they form a contact pair that is characterized by higher strength of components, anti-friction and anti-wear properties.

PL

Dyskretno-ciągłe hartowanie jest proponowane dla powierzchni stykających się elementów maszyn. Metoda sugeruje, że jedna część jest utwardzana w dyskretny sposób, a druga jest utwardzana w sposób ciągły na całej powierzchni. Uzyskana para kontaktów uzyskuje pozytywne cechy z każdej z zastosowanych technik hartowania. Działanie proponowanej technologii ocenia się za pomocą analizy naprężeń badanych fragmentów. W przeciwieństwie do tradycyjnych technologii hartowania, w nowym systemie zastosowano mechanizmy ujemnego sprzężenia zwrotnego w systemie "obciążenie - interakcja stykowa - tarcie - zużycie". Skutkuje to dodatnim efektem integralnym, który przewyższa indywidualne wpływ każdej z zastosowanych technologii hartowania. Zapewnia bardziej korzystne warunki kontaktu, w szczególności rozkład naprężeń kontaktowych. Prowadzi to do zmniejszenia zużycia, co z kolei zapobiega dramatycznemu wzrostowi obciążeń roboczych. W konsekwencji następuje stabilizacja badanych procesów. Zwiększenie warunków kontaktu hartowanych elementów wykazano za pomocą analizy strukturalnej reprezentatywnego fragmentu badanego układu. Wyniki modelowania numerycznego potwierdzają zalety tej technologii. Lokalnie utwardzone strefy rzeczywiście przenoszą duże obciążenia. Niemniej jednak, tarcie i zużycie w utwardzonych strefach są zmniejszone dzięki ulepszonym właściwościom tribomechanicznym materiału w porównaniu z pozostałą częścią obiektu. Ciągłe testowanie próbki dodatkowo wzmacnia ten efekt. W szczególności materiały metalowe, takie jak aluminium, są pokryte cienką warstwą tlenków utworzoną przez zastosowanie silnego prądu elektrycznego w specjalnym medium. Skonsolidowana faza tlenkowa tworzy warstwy powierzchniowe spełniające rolę strukturalną. Wraz z dyskretnie hartowaną powierzchnią części reakcyjnej tworzą parę kontaktową, która charakteryzuje się większą wytrzymałością komponentów, właściwościami przeciwciernymi i przeciwzużyciowymi.

15

Napęd serwokrokowy Ezi-SERVO-II-Plus-E z pozycjonerem sterowany przez EtherNET

Haliniak T.

Napędy i Sterowanie

|

2018

|

R. 20, nr 9

83--84

PL

Ezi-SERVO-II-Plus-E to napędy serwokrokowe (zwane również hybrydowymi) pracujące w zamkniętej pętli sprzężenia zwrotnego, która zapewnia doskonałą powtarzalność pozycjonowania. Daje ona jednocześnie gwarancję niezgubienia kroku przez silnik nawet przy nagłych zmianach obciążenia. Algorytm programowego tłumienia wibracji gwarantuje natomiast bardzo wysoką kulturę pracy silnika. Producentem opisywanych napędów jest koreańska firma Fastech.

16

Vibration analysis and control of locomotive system

Shireesha Y., Venkata Suresh B., Sateesh B.

Mechanics and Mechanical Engineering

|

2018

|

Vol. 22, nr 1

195--205

EN

Vibration is an undesirable phenomenon of ground vehicles like locomotives and vibration control of vehicle suspension system is an active subject of research. The main aim of the present work is to modeling and analysis of locomotive system. The simplified equations for dynamical locomotive are firstly established. Then the dynamical nature of the locomotive without control is investigated, and also active control suspension and passive control suspension are compare and discussed. The obtained simulation shows that suspension of the locomotive with feedback control could decrease the locomotive vibration. According to the above control strategy along with angular acceleration it also reduces the possibility of vibration of the locomotive body, to improves the stability of vehicle operation.

17

A model for random fire induced tree-grass coexistence in savannas

Klimasara P., Tyran-Kamińska M.

Mathematica Applicanda

|

2018

|

Vol. 46, no. 1

87--96

EN

Tree-grass coexistence in savanna ecosystems depends strongly on environment al disturbances out of which crucial is fire. Most modeling attempts in the literature lack stochastic approach to fire occurrences which is essential to reflect their unpredictability. Existing models that actually include stochasticity of fire are usually analyzed only numerically. We introduce a new minimalistic model of treegrass coexistence where fires occur according to a stochastic process. We use the tools of the linear semigroup theory to provide a more careful mathematical analysis of the model. Essentially we show that there exists a unique stationary distribution of tree and grass biomasses.

PL

Sawanny zajmują ok. 20% lądowej powierzchni Ziemi. W tym ekosystemie korony drzew są na tyle oddzielone od siebie nawzajem, że do podłoża dociera wystarczająco dużo światła, aby utrzymywała się równomierna warstwa traw. Takie długotrwałe współistnienie traw i drzew, czyli brak konwersji do łąki lub lasu, jest możliwe dzięki różnym czynnikom. Uważa się, że najważniejsze z nich to powtarzające się pożary, obfitość pory deszczowej oraz uszczuplanie warstwy roślinnej przez roślinożerców i działalność człowieka. Większość dotychczasowych modeli koegzystencji traw i drzew jest deterministyczna, jeżeli już przyjmuje się stochastyczne występowanie pożarów lub deszczu, to zazwyczaj w bardzo uproszczonej formie, a analiza jest przeprowadzana numerycznie. W tym artykule wprowadzamy uproszczony model, składający się z układu równań różniczkowych, opisujących wzrost traw i drzew w czasie oraz procesu stochastycznego, odpowiadającego za losowe pojawianie się pożarów. Analizujemy ten proces, korzystając z metod teorii półgrup liniowych, co pozwala nam pokazać, że startując z dowolnego rozkładu początkowego biomasy traw i drzew, po odpowiednio długim czasie rozkład tych biomas się stabilizuje. Istnieje jedyny (absolutnie ciągły względem dwuwymiarowej miary Lebesgue’a) taki rozkład stacjonarny. Planujemy rozbudować zaproponowany model o dodatkowe czynniki środowiskowe wymienione wcześniej oraz konkurencje o zasoby pomiędzy trawami a sadzonkami drzew. Ponadto podobne uwzględnienie stochastycznej natury występowania pożarów można uwzględnić w modelowaniu innych zjawisk przyrodniczych jak związek pomiędzy pożarami lasów a populacją żywiących się korą sosen chrząszczy.

18

Synchronization of state-feedback-controlled doubly fed induction generator with the grid

Szypulski M., Iwański G.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2018

|

Vol. 66, nr 5

675--685

EN

This paper presents state feedback control with a linear-quadratic regulator of a doubly fed induction generator. Resonant terms are added to the plant model in order to provide disturbance rejection and reference tracking. A new approach to controlling a parameter varying linear model of the induction machine is presented, allowing to apply a linear-quadratic regulator to the doubly fed induction generator. The control scheme described herein is suitable for the doubly fed induction generator operating under unbalanced stator voltage conditions, because the controller with resonant terms is built in the stationary αβ coordinate system. In it, the positive and negative symmetrical sequences have equal frequencies. The paper highlights specific problems associated with state feedback control of the doubly fed induction generator, i.e. the process of generator connection to an unbalanced grid. In contrast with classical voltage-oriented cascade control methods, in state feedback control of a stand-alone doubly fed induction generator there is no separate rotor current controller. This may cause over-current problem during DFIG synchronization with the grid which has been solved in this paper. Voltage synchronization and grid operation of the generator were tested in a laboratory rig with a 7.5 kW wound-rotor induction machine.

19

Suboptimal control of nonlinear continuous-time locally positive systems using input-state linearization and SDRE approach

Bernat J., Kołota J., Stępień S., Superczyńska P.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2018

|

Vol. 66, nr 1

17--21

EN

The infinite time suboptimal control problem for continuous-time nonlinear positive systems is formulated and solved. A solution to the problem using input-state linearization and state-dependent Riccati equation method (SDRE) is established, a procedure for solving the problem is proposed and illustrated with a numerical example.

20

High-performance PMSM servo-drive with constrained state feedback position controller

Tarczewski T., Skiwski M., Niewiara L. J., Grzesiak L. M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2018

|

Vol. 66, nr 1

49--58

EN

This paper describes high-performance permanent magnet synchronous motor (PMSM) servo-drive with constrained state feedback (SFC) position controller. Superior behavior of the control system has been achieved by applying SFC with constraints handling method based on a posteriori model predictive approach (MPAC). The concept utilizes predictive equations obtained from discrete-time model of the PMSM to compute control signals which generate admissible values of the future state variables. The novelty of the proposed solution lies in the limitation of several state-space variables in servo-drive control system. Since MPAC has firstly been applied to limit more than one state-space variable of the plant, necessary conditions for introducing constraints into multivariable control system with SFC are depicted. Due to the low complexity of proposed algorithm, a low cost microprocessor, STM32F4, is employed to execute the state feedback position control with model predictive approach to constraints handling. Experimental results show that the proposed control method provides superior performance of PMSM servodrive with modern SiC based voltage source inverter (VSI).