Wyniki wyszukiwania - Biblioteka Nauki

1

A Novel Design Of An NTC Thermistor Linearization Circuit

100%

Lukić J. , Denić D.

Metrology and Measurement Systems

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2015

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tom Vol. 22, nr 3

351--362

EN

A novel design of a circuit used for NTC thermistor linearization is proposed. The novelty of the proposed design consists in a specific combination of two linearization circuits, a serial-parallel resistive voltage divider and a two-stage piecewise linear analog-to-digital converter. At the output of the first linearization circuit the quasi-linear voltage is obtained. To remove the residual voltage nonlinearity, the second linearization circuit, i.e., a two-stage piecewise linear analog-to-digital converter is employed. This circuit is composed of two flash analog-to-digital converters. The first analog-to-digital converter is piecewise linear and it is actually performing the linearization, while the second analog-to-digital converter is linear and it is performing the reduction of the quantization error introduced by the first converter. After the linearization is performed, the maximal absolute value of a difference between the measured and real temperatures is 0.014°C for the temperature range between - 25 and 75°C, and 0.001°C for the temperature range between 10 and 40°C.

2

Linearyzacja modelu matematycznego siłownika hydraulicznego połączonego z ramieniem manipulatora

100%

Cedro L. , Janecki D.

Pomiary Automatyka Kontrola

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2009

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tom R. 55, nr 2

126-130

PL

Streszczenie W pracy przedstawiono metodę linearyzacji modelu matematycznego układu hydraulicznego połączonego z ramieniem manipulatora. Układ zamodelowano w dwóch postaciach: w postaci równań różniczkowych, oraz modelu quasi-liniowego. Uzyskany model uproszczony poddano weryfikacji z modelem dokładnym. Model taki może być wykorzystany w procesach identyfikacji metodą najmniejszych kwadratów, która jest jedną z najbardziej efektywnych metod identyfikacji. Drugim obszarem zastosowań może być projektowanie układów regulacji.

EN

The paper presents the method of linearization of a hydraulic actuator system connected to a manipulator arm. Fig. 1 shows a drive system supplied with constant pressure . The flow controller (2) acts as a throttling valve, while the hydraulic actuator (1) is a receiver. The constant pressure is provided by the pump (3). The arm-actuator system presented in Fig. 2 is a one-dimensional model. In the analysis, the elements connecting the actuator to the arm are not taken into consideration. This way it is easier to determine the system dynamic properties. The method used in this study requires expanding the linear function in a Taylor series around the operating point and considering linear terms only. After linearization of the mathematical model of a manipulator connected to a hydraulic actuator, there was obtained a simplified model (7) representing well the real system model behaviour (1). The simplified model was compared with the accurate one. In the case of the second-order, quasi-linear model and the mathematical model of the hydraulic actuator system, both signals fully coincide (Fig. 6). That is why the simplification to such a form is justified. The hydraulic actuator system was designed in two forms: as differential equations(1) (accurate model), and as a quasi-linear model (10) (simplified one). The simplified model can be used for identification purposes using the least squares method, which is one of the most effective identification method. Another area of application can be design of control systems.

3

Control of an induction motor using sliding mode linearization

100%

Etien E. , Cauet S. , Rambault L. , Champenois G.

International Journal of Applied Mathematics and Computer Science

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2002

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tom 12

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nr 4

523-531

EN

Nonlinear control of the squirrel induction motor is designed using sliding mode theory. The developed approach leads to the design of a sliding mode controller in order to linearize the behaviour of an induction motor. The second problem described in the paper is decoupling between two physical outputs: the rotor speed and the rotor flux modulus. The sliding mode tools allow us to separate the control from these two outputs. To take account of parametric variations, a model-based approach is used to improve the robustness of the control law despite these perturbations. Experimental results obtained with a laboratory setup illustrate the good performance of this technique.

4

Weakly nonlinear regression model with constraints I: nonlinear hypothesis

100%

Kubácek L. , Tesaríková E.

Discussiones Mathematicae Probability and Statistics

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2005

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tom 25

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nr 1

115-133

EN

The problem considered is under which conditions in weakly nonlinear regression model with constraints I a weakly nonlinear hypothesis can be tested by linear methods. The aim of the paper is to find a region around the approximate value of the regression parameter with the following property. If we are certain that the actual value of the regression parameter is in this region, then the linear method of testing can be used without any significant deterioration of the inference.

5

An Analysis of influence of SMA material on dynamic properties of a spring taking into account constructional friction

88%

Gałkowski Z.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2002

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tom Vol. 6, No 3

351-361

EN

In this paper, an analysis of forced transverse harmonic vibration with constant changes of the exciting force in a dynamic system consisting of two beams is presented together with a model of a leaf spring. In this junction both beams are made of shape memory material (SMA). The constructional friction is also taken into account. For the purpose of the analysis an equivalent linearization of the elasticity-damping features of the beams was conducted. As an effect of linearization a junction was acquired with both stiffness of elements and viscosity damping. The obtained differential equations were solved using the asymptotic Bogolubov-Krylov-Mitropolski method. The results of the conducted simulation are presented on graphs, showing the influence of unitary pressure on the system's damping properties.

6

Investigation of the dynamics of singular protected systems

88%

Naumeyko I. , Alja'afreh M.

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes

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2016

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tom Vol. 5, No 4

37--42

EN

The analysis of asymptotic representations of the systems protected from harmful influences is carried out. Various types of general models of the "manmachineenvironment" with protection are considered. Each of them adequately describes some of the practically important qualities of the object, and they all together describe the object in terms of its safe operation. The dynamic properties of complex ergonomic systems, presented in the form of systems of differential equations with a small parameter at the derivative are investigated The methods of reducing the impact on the person of harmful factors are theoretically substantiated. The dynamic protection response speed is considered to be significantly greater than the harmful factor production rate. Numerical solution of the general problem and the analytical solution for autonomous case is obtained for harmful effects. By using asymptotic the system of equations has been solved in closed form not only for autonomous case, but also for parameters smoothly changing in time. The estimates of the cost of protection was obtained for the various cost-functionals and for different functions in the right-hand side of the equation describing the dynamics of protection. To assess the accuracy of model calculations and for graphic representation of the results mathematical package MAXIMA is used.

7

Oscillatory criteria via linearization of half-linear second order delay differential equations

88%

Baculikova B. , Dzurina J.

Opuscula Mathematica

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2020

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tom Vol. 40, no. 5

523--536

EN

In the paper, we study oscillation of the half-linear second order delay differential equations of the form [formula]. We introduce new monotonic properties of its nonoscillatory solutions and use them for linearization of considered equation which leads to new oscillatory criteria. The presented results essentially improve existing ones.

8

Positivity and linearization of a class of nonlinear continuous-time systems by state feedbacks

88%

Kaczorek T.

International Journal of Applied Mathematics and Computer Science

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2015

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tom 25

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nr 4

827-831

EN

The positivity and linearization of a class of nonlinear continuous-time system by nonlinear state feedbacks are addressed. Necessary and sufficient conditions for the positivity of the class of nonlinear systems are established. A method for linearization of nonlinear systems by nonlinear state feedbacks is presented. It is shown that by a suitable choice of the state feedback it is possible to obtain an asymptotically stable and controllable linear system, and if the closed-loop system is positive then it is unstable.

9

External Linearization of Unobservable Discrete-time Systems

88%

Pawłuszkiewicz E.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2002

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tom Vol. 50, Nr 2

161--173

EN

The paper presents the problem of external dynamic linearization of the discret-time systems defined on smooth or analytic manifold. The main result is that nonlinear system is externally dynamically feedback linearizable if its difference output universe is free. Moreover, the number of free generators of this universe coincide with the number of controls of the given system.

10

Minimise Ad (?/*In-)finitum? In Defense of Weakly Cartographic Computational Models

88%

Cegłowski P.

Poznań Studies in Contemporary Linguistics

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2008

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tom 44

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nr 2

215-245

EN

This paper provides a critical overview of the strongly derivational and non-cartographic approaches to syntax based solely on the relation between a newly selected lexical item (LI) and the so-called derivational space (the existing syntactic object) treated as the pivot of the syntactic derivation. Specifically, it is argued that, given the asymmetry requirement requisite for linearization, as stated in Kayne's (1994) Linear Correspondence Axiom (LCA) and Chomsky's (1994) Bare Phrase Structure (BPS), the abovementioned procedure is unattainable in certain strongly derivational syntactic configurations. The latter sections of the paper, while still arguing against the excessively minimized derivational space, focus on the non-cartographic Escape system proposed by Zwart (2007). It is shown that the data (comprising mostly the so-called "look-ahead"- based cases) that prove problematic for Escape can be captured within a moderately (i.e. weakly) cartographic view of the left periphery in accord with Thráinsson's (1996) Limited Diversity Hypothesis.

11

Fractional Order Sliding Mode Speed Control of Feedback Linearized Induction Motor

75%

Fetene Y. , Shibeshi D.

Power Electronics and Drives

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2020

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tom Vol. 5 (40)

109--122

EN

Induction machines have of late become the most popular workhorses in the industry replacing DC machines because of their advantages, such as reduced cost, reliability and the absence of commutators, which make them adapt to unfavourable conditions with lower maintenance requirement. However, higher-order models of AC machines, nonlinearities in model equations, uncertainties in parameters and load disturbances make induction motors difficult to control than that of DC motors. In this paper, a robust control strategy considering the recent advances in technology is proposed employing input-output feedback linearization for the exact decoupling of electromagnetic torque and rotor flux using fractional-order sliding mode controller (SMC) for the outer speed loop. The sliding mode observer is also designed to extract the rotor flux from the DC input voltage of the inverter and stator current measurements. Finally, a comparison between the commonly used proportional integral and derivative (PID) controller and the proposed fractional-order SMCs is made and the conclusion is reached.

12

Błąd linearyzacji potęgowej krzywej konsumcyjnej

75%

Kozieł S. R.

Gospodarka Wodna

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2002

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tom Nr 10

425-427

PL

Przedstawiono analizę dokładności estymacji parametrów regresji opisującą krzywą konsumcyjną na przykładzie Wisły w profilu Nadwilanówka.

EN

The paper presents the analysis of accuracy of estimation of regression parameters describing the consumption curve based on the case of the Nadwilanówka cross-section of the Vistula river.

13

Test bench and simulation research on hydrodynamic torque converter for different input signals

75%

Wozniak M. , Siczek K. , Pawelski Z.

Journal of KONES

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2016

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tom Vol. 23, No. 4

561--568

EN

This paper presents the experimental research and simulating results of a ZM130 hydrodynamic torque converter under steady and unsteady working conditions with an external step signal and sinus on turbine’s shaft on a modified test bench. The mathematical model of torque converter was described by the one-dimensional flow theory with variable loss coefficients. The character of received equations from test bend showed by linearized transmittance functions with variable coefficients. For test bend object identification researches will be used an Identification Toolbox from a mathematical code in Matlab, which enables to create transfer functions as a linear model from measurements data as they got the highest correctness level with input signal (as they get the best correction level with input signal on the pump´s shaft). This mathematical model for dynamic loads will be verified by experimental tests. The aim of the carried out studies was determination the effect of sampling time decreasing on the quality of measured parameters. Results of present investigations were compared with those obtained earlier, but for the same input signals .It is possible to affirm that proposed theoretical model imitates the change of dynamic parameters, and the same the property of the torque converter. Researches led on the test bend with extortion input torque sinus signal on the turbine’s shaft confirmed correctness of this model.

14

Nowe metody linearyzacji platynowych czujników temperatury PT100

75%

Kowalski G.

Elektronika : konstrukcje, technologie, zastosowania

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2003

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tom Vol. 44, nr 12

33-34

PL

W artykule opisane są dwie precyzyjne metody linearyzacji platynowych czujników temperatury PT100, w których wykorzystane są techniki przetwarzania analogowo-cyfrowego.

EN

In article, there are described two technics of linearization platinum temperature sensors PT100, where analog and digital processing technics are used.

15

Two-dimensional fractal linearization of distribution curves

75%

Ahmed H. A. M. , Drzymała J.

Physicochemical Problems of Mineral Processing

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2005

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tom Vol. 39

129-139

EN

Distribution curves of properties of materials (size, density, hydrophobicity, etc.) are important for characterization and controlling separation results. Frequently, the mass-based size distribution curves are linearized using various functions including those of Rosin-Rammler, Gates-Gaudin- Schumann, and Gaudin-Meloy. In this paper, a fractal approach was tested for linearization of the size distribution curves. It was shown in the paper that the three-dimensional (3D) fractal linearization equation is the same as the Gates-Gaudin-Schumann formula. It was also shown that area-based 2D fractal can be used for linearization of the size distribution curves provided that an appropriate area, on which the sample is spread, is determined. It was also shown that in some cases more than one fractal is necessary for linearization of the size distribution curve.

PL

Krzywe rozkładu właściwości materiałów ziarnistych (rozmiaru, gęstości, hydrofobowości, itd.) są bardzo przydatne do charakteryzowania i kontroli wyników separacji. Często krzywe te, a zwłaszcza krzywe składu ziarnowego, są linearyzowane za pomocą różnych funkcji matematycznych takich jak Rosina-Rammlera, Gatesa-Gaudina-Schumanna, czy też Gaudina-Meloy’a. W tej pracy rozważano zastosowanie rachunku fraktalnego do linearyzacji krzywej składu ziarnowego. W pracy wykazano, że trójwymiarowa (3D) fraktalna linearyzacja składu ziarnowego jest identyczna z równaniem Gatesa- Gaudina-Schumanna. Wykazano również, że dwuwymiarowy (2D) fraktal uwzględniający powierzchnię ziaren może być użyty do linearyzacji krzywej składu ziarnowego pod warunkiem odpowiedniego doboru powierzchni, na której umieszcza się rozpatrywana próbę ziaren. Pokazano także, że w niektórych przypadkach do liniowego opisu krzywej składu ziarnowego niezbędne staje się użycie więcej niż jednego fraktala. Linearyzacja za pomocą dwuwymiarowego fraktala jest w istocie przybliżaniem składu ziarnowego za pomocą dwóch dopasowywanych parametrów, to jest wymiaru fraktalnego oraz powierzchni, na której umieszcza się próbkę.

16

Control of an Induction Motor Using Sliding Mode Linearization

75%

Etien E. , Cauet E. , Rambault L. , Champenois G.

International Journal of Applied Mathematics and Computer Science

|

2002

|

tom Vol. 12, no 4

523-531

EN

Nonlinear control of the squirrel induction motor is designed using sliding mode theory. The developed approach leads to the design of a sliding mode controller in order to linearize the behaviour of an induction motor. The second problem described in the paper is decoupling between two physical outputs: the rotor speed and the rotor flux modulus. The sliding mode tools allow us to separate the control from these two outputs. To take account of parametric variations, a model-based approach is used to improve the robustness of the control law despite these perturbations. Experimental results obtained with a laboratory setup illustrate the good performance of this technique.

17

Filtracja Kalmana w technice na przykładzie urządzenia SST

75%

Zając M.

Zeszyty Naukowe Wyższej Szkoły Informatyki

|

2013

|

tom Vol. 12, Nr 1

5--20

PL

W artykule podjęto próbę opisu filtracji Kalmana zarówno dla zagadnień liniowych jak i nieliniowych. Omówiono linearyzację dla zagadnień nieliniowych, wykorzystano zgromadzone informacje do budowy praktycznej filtra Kalmana. Zbadano możliwość wykorzystania założeń teoretycznych w praktycznej realizacji dotyczącej urządzenia pomiarowego i badania właściwości ferromagnetyka przy wykorzystaniu SST.

EN

It is an attempt to describe the Kalman filter both for linear and non-linear. The linearization for nonlinear phenomenon was descussed, and information were used to build practical Kalman filter.

18

Modelowanie normalnych charakterystyk sztywnościowych nieliniowego podłoża sprężystego

75%

Grzejda R.

Modelowanie Inżynierskie

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2013

|

tom T. 16, nr 47

87--92

PL

Przedstawiono modelowanie i obliczenia połączenia stykowego obciążonego niesymetrycznie. Przyjęto fizyczny model połączenia dwóch elementów korpusowych traktowanych jako ciała odkształcalne lub nieodkształcalne. Umowną warstwę stykową pomiędzy elementami łączonymi opisano za pomocą nieliniowego modelu Winklera. Zaproponowano model połączenia stykowego uwzględniający sztywność stykową uzyskaną na podstawie badań doświadczalnych. Zamieszczono przykładowe obliczenia rozkładu normalnych nacisków i odkształceń stykowych normalnych na powierzchni ściskanych elementów.

EN

In the paper modelling and calculations of a contact joint loaded by an asymmetrical force is presented. The physical model of the joint consists of two flange elements treated as flexible or inflexible bodies. Between joined elements the nonlinear Winkler model of a contact layer is taken into account. The model of the contact joint considering experimental characteristics of the nonlinear elastic foundation is proposed. As results obtained from the calculations, examples of pressure and normal contact deformations distributions are shown.

19

Supervisory predictive control and on-line set-point optimization

75%

Tatjewski P.

International Journal of Applied Mathematics and Computer Science

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2010

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tom 20

|

nr 3

483-495

EN

The subject of this paper is to discuss selected effective known and novel structures for advanced process control and optimization. The role and techniques of model-based predictive control (MPC) in a supervisory (advanced) control layer are first shortly discussed. The emphasis is put on algorithm efficiency for nonlinear processes and on treating uncertainty in process models, with two solutions presented: the structure of nonlinear prediction and successive linearizations for nonlinear control, and a novel algorithm based on fast model selection to cope with process uncertainty. Issues of cooperation between MPC algorithms and on-line steady-state set-point optimization are next discussed, including integrated approaches. Finally, a recently developed two-purpose supervisory predictive set-point optimizer is discussed, designed to perform simultaneously two goals: economic optimization and constraints handling for the underlying unconstrained direct controllers.

20

Linearization of non-linear state equation

75%

Jordan A. J.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2006

|

tom Vol. 54, nr 1

63-73

EN

The paper presents an overview of linearization methods of the non-linear stale equation. The linearization is developed from the point of view of the application in the theoretical electrotechnics. Same aspects of these considerations can be used in the control theory. In particular the main emphasis is laid on three methods of linearization, i.e.: Taylor's series expansion, optimal linearization method and global linearization method. The theoretical investigations are illustrated using the non-linear circuit composed of a solar generator and a DC motor. Finally, the global linearization method is presented using several examples, Le. the asynchronous slip-ring motor and non-linear diode. Furthermore the principal theorem concerning the BIBS stability (bounded-input bounded stale) is introduced.