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Wyszukujesz frazę "model estimation" wg kryterium: Temat


Wyświetlanie 1-15 z 15
Tytuł:
Model-based techniques for virtual sensing of longitudinal flight parameters
Autorzy:
Hardier, G.
Seren, C.
Ezerzere, P.
Powiązania:
https://bibliotekanauki.pl/articles/330954.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
model based estimation
fault detection
virtual sensor
Kalman filtering
surrogate modelling
estymacja modelu
detekcja uszkodzeń
sensor wirtualny
filtracja Kalmana
Opis:
Introduction of fly-by-wire and increasing levels of automation significantly improve the safety of civil aircraft, and result in advanced capabilities for detecting, protecting and optimizing A/C guidance and control. However, this higher complexity requires the availability of some key flight parameters to be extended. Hence, the monitoring and consolidation of those signals is a significant issue, usually achieved via many functionally redundant sensors to extend the way those parameters are measured. This solution penalizes the overall system performance in terms of weight, maintenance, and so on. Other alternatives rely on signal processing or model-based techniques that make a global use of all or part of the sensor data available, supplemented by a model-based simulation of the flight mechanics. That processing achieves real-time estimates of the critical parameters and yields dissimilar signals. Filtered and consolidated information is delivered in unfaulty conditions by estimating an extended state vector, including wind components, and can replace failed signals in degraded conditions. Accordingly, this paper describes two model-based approaches allowing the longitudinal flight parameters of a civil A/C to be estimated on-line. Results are displayed to evaluate the performances in different simulated and real flight conditions, including realistic external disturbances and modeling errors.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2015, 25, 1; 23-38
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-stage instrumental variables identification of polynomial Wiener systems with invertible nonlinearities
Autorzy:
Janczak, Andrzej
Korbicz, Józef
Powiązania:
https://bibliotekanauki.pl/articles/330751.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
nonlinear system
parameter estimation
dynamic model
polynomial model
układ nieliniowy
estymacja parametru
model dynamiczny
model wielomianowy
Opis:
A new two-stage approach to the identification of polynomial Wiener systems is proposed. It is assumed that the linear dynamic system is described by a transfer function model, the memoryless nonlinear element is invertible and the inverse nonlinear function is a polynomial. Based on these assumptions and by introducing a new extended parametrization, the Wiener model is transformed into a linear-in-parameters form. In Stage I, parameters of the transformed Wiener model are estimated using the least squares (LS) and instrumental variables (IV) methods. Although the obtained parameter estimates are consistent, the number of parameters of the transformed Wiener model is much greater than that of the original one. Moreover, there is no unique relationship between parameters of the inverse nonlinear function and those of the transformed Wiener model. In Stage II, based on the assumption that the linear dynamic model is already known, parameters of the inverse nonlinear function are estimated uniquely using the IV method. In this way, not only is the parameter redundancy removed but also the parameter estimation accuracy is increased. A numerical example is included to demonstrate the practical effectiveness of the proposed approach.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2019, 29, 3; 571-580
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variable- and Fixed-Structure Augmented Interacting Multiple-Model Algorithms for Manoeuvring Ship Tracting Based on New Ship Models
Autorzy:
Semerdjiev, E.
Mihaylova, L.
Powiązania:
https://bibliotekanauki.pl/articles/911219.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
model niepewności
estymacja parametryczna
Interacting Multiple Model (IMM) algorithm
model uncertainty
state and parameter estimation
Opis:
Real-world tracking applications are related to a number of difficulties caused by the presence of different kinds of uncertainty, e.g. unknown or incompletely known system models and statistics of random processes or abrupt changes in the system modes of functioning. These problems are especially complicated in the marine navigation practice, where the commonly-used simple models of rectilinear or curvilinear target motions are not adequate for highly non-linear dynamics of the manoeuvring ship motion. A solution to these problems is to derive more suitable descriptions of real ship dynamics and to design adaptive estimation algorithms. After an analysis of basic hydrodynamic models, new ship models are derived in the paper. They are implemented in two versions of the Interacting Multiple Model (IMM) algorithm which has become very popular recently. The first one is a standard IMM version based on fixed model structures (FS's). They represent various modes of ship motion, distinguished by their rates of turns. The same rate of turn is additionally adjusted in the proposed new augmented versions of the IMM (AIMM) algorithm by using FS's and variable structures (VS's) of adaptive models estimating the current change in the system control parameters. Monte Carlo simulation experiments indicate that the VS AIMM algorithm outperforms the FS AIMM and FS IMM ones with respect to both accuracy and adaptability.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2000, 10, 3; 591-604
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An adaptive observer design approach for a class of discrete-time nonlinear systems
Autorzy:
Srinivasarengan, K.
Ragot, J.
Aubrun, C.
Maquin, D.
Powiązania:
https://bibliotekanauki.pl/articles/330844.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
adaptive observer
joint state estimation
parameter estimation
Takagi-Sugeno model
time-varying parameter estimation
sector nonlinearity transformation
discrete-time nonlinear systems
obserwator adaptacyjny
identyfikacja parametrów
model Takagi-Sugeno
transformacja nieliniowa
dyskretny układ nieliniowy
Opis:
We consider the problem of joint estimation of states and some constant parameters for a class of nonlinear discrete-time systems. This class contains systems that could be transformed into a quasi-LPV (linear parameter varying) polytopic model in the Takagi–Sugeno (T–S) form. Such systems could have unmeasured premise variables, a case usually overlooked in the observer design literature. We assert that, for such systems in discrete-time, the current literature lacks design strategies for joint state and parameter estimation. To this end, we adapt the existing literature on continuous-time linear systems for joint state and time-varying parameter estimation. We first develop the discrete-time version of this result for linear systems. A Lyapunov approach is used to illustrate stability, and bounds for the estimation error are obtained via the bounded real lemma. We use this result to achieve our objective for a design procedure for a class of nonlinear systems with constant parameters. This results in less conservative conditions and a simplified design procedure. A basic waste water treatment plant simulation example is discussed to illustrate the design procedure.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2018, 28, 1; 55-67
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Iterative estimators of parameters in linear models with partially variant coefficients
Autorzy:
Hu, S.
Meinke, K.
Chen, R.
Huajiang, O.
Powiązania:
https://bibliotekanauki.pl/articles/929607.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
model liniowy
estymacja parametrów
algorytm iteracyjny
współczynnik zmienności
linear model
parameter estimation
iterative algorithms
variant coefficients
Opis:
A new kind of linear model with partially variant coefficients is proposed and a series of iterative algorithms are introduced and verified. The new generalized linear model includes the ordinary linear regression model as a special case. The iterative algorithms efficiently overcome some difficulties in computation with multidimensional inputs and incessantly appending parameters. An important application is described at the end of this article, which shows that this new model is reasonable and applicable in practical fields.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2007, 17, 2; 179-187
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameters estimation for a patellofemoral joint of a human knee using a vector method
Autorzy:
Ciszkiewicz, A.
Knapczyk, J.
Powiązania:
https://bibliotekanauki.pl/articles/264420.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
model
knee joint
vector method
estimation
position and displacements
staw kolanowy
model stawu kolanowego
metoda wektorowa
Opis:
Position and displacement analysis of a spherical model of a human knee joint using the vector method was presented. Sensitivity analysis and parameter estimation were performed using the evolutionary algorithm method. Computer simulations for the mechanism with estimated parameters proved the effectiveness of the prepared software. The method itself can be useful when solving problems concerning the displacement and loads analysis in the knee joint.
Źródło:
International Journal of Applied Mechanics and Engineering; 2015, 20, 3; 629-636
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Set-membership identifiability of nonlinear models and related parameter estimation properties
Autorzy:
Jauberthie, C.
Travé-Massuyès, L.
Verdière, N.
Powiązania:
https://bibliotekanauki.pl/articles/331411.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
identifiability
bounded uncertainty
set membership estimation
nonlinear dynamic model
identyfikowalność
niepewność ograniczona
zbiór estymacyjny
model dynamiczny nieliniowy
Opis:
Identifiability guarantees that the mathematical model of a dynamic system is well defined in the sense that it maps unambiguously its parameters to the output trajectories. This paper casts identifiability in a set-membership (SM) framework and relates recently introduced properties, namely, SM-identifiability, μ-SM-identifiability, and ε-SM-identifiability, to the properties of parameter estimation problems. Soundness and ε-consistency are proposed to characterize these problems and the solution returned by the algorithm used to solve them. This paper also contributes by carefully motivating and comparing SM-identifiability, μ-SM-identifiability and ε-SM-identifiability with related properties found in the literature, and by providing a method based on differential algebra to check these properties.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2016, 26, 4; 803-813
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameters estimation for the spherical model of the human knee joint using vector method
Autorzy:
Ciszkiewicz, A.
Knapczyk, J.
Powiązania:
https://bibliotekanauki.pl/articles/955119.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
staw kolanowy
symulacja komputerowa
biomechanika
model
knee joint
vector method
estimation
position and displacements
Opis:
Position and displacement analysis of a spherical model of a human knee joint using the vector method was presented. Sensitivity analysis and parameter estimation were performed using the evolutionary algorithm method. Computer simulations for the mechanism with estimated parameters proved the effectiveness of the prepared software. The method itself can be useful when solving problems concerning the displacement and loads analysis in the knee joint.
Źródło:
International Journal of Applied Mechanics and Engineering; 2014, 19, 3; 523-537
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of parametric models with a priori knowledge of process properties
Autorzy:
Janiszowski, K. B.
Wnuk, P.
Powiązania:
https://bibliotekanauki.pl/articles/330128.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
absolute error measure
constrained parameters estimation
parametric MISO models
błąd bezwzględny
estymacja parametrów
model parametryczny
Opis:
An approach to estimation of a parametric discrete-time model of a process in the case of some a priori knowledge of the investigated process properties is presented. The knowledge of plant properties is introduced in the form of linear bounds, which can be determined for the coefficient vector of the parametric model studied. The approach yields special biased estimation of model coefficients that preserves demanded properties. A formula for estimation of the model coefficients is derived and combined with a recursive scheme determined for minimization of the sum of absolute model errors. The estimation problem of a model with known static gains of inputs is discussed and proper formulas are derived. This approach can overcome the non-identifiability problem which has been observed during estimation based on measurements recorded in industrial closed-loop control systems. The application of the proposed approach to estimation of a model for an industrial plant (a water injector into the steam flow in a power plant) is presented and discussed.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2016, 26, 4; 767-776
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic location models of mobile sensors for travel time estimation on a freeway
Autorzy:
Sun, Weiwei
Shen, Liang
Shao, Hu
Liu, Pengjie
Powiązania:
https://bibliotekanauki.pl/articles/1838205.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
traffic mobile sensor
dynamic location model
travel time estimation
simulated annealing algorithm
data fusion
czujnik ruchu
model lokalizacji
szacowanie czasu podrózy
fuzja danych
Opis:
Travel time estimation for freeways has attracted much attention from researchers and traffic management departments. Because of various uncertain factors, travel time on a freeway is stochastic. To obtain travel time estimates for a freeway accurately, this paper proposes two traffic sensor location models that consider minimizing the error of travel time estimation and maximizing the collected traffic flow. First, a dynamic optimal location model of the mobile sensor is proposed under the assumption that there are no traffic sensors on a freeway. Next, a dynamic optimal combinatorial model of adding mobile sensors taking account of fixed sensors on a freeway is presented. It should be pointed out that the technology of data fusion will be adopted to tackle the collected data from multiple sensors in the second optimization model. Then, a simulated annealing algorithm is established to find the solutions of the proposed two optimization models. Numerical examples demonstrate that dynamic optimization of mobile sensor locations for the estimation of travel times on a freeway is more accurate than the conventional location model.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2021, 31, 2; 271--287
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter identifiability for nonlinear LPV models
Autorzy:
Srinivasarengan, Krishnan
Ragot, José
Aubrun, Christophe
Maquin, Didier
Powiązania:
https://bibliotekanauki.pl/articles/2134053.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
parameter identifiability
parameter estimation
linear parameter varying model
parity space approach
null space
identyfikacja parametrów
szacowanie parametrów
spacja zerowa
Opis:
Linear parameter varying (LPV) models are being increasingly used as a bridge between linear and nonlinear models. From a mathematical point of view, a large class of nonlinear models can be rewritten in LPV or quasi-LPV forms easing their analysis. From a practical point of view, that kind of model can be used for introducing varying model parameters representing, for example, nonconstant characteristics of a component or an equipment degradation. This approach is frequently employed in several model-based system maintenance methods. The identifiability of these parameters is then a key issue for estimating their values based on which a decision can be made. However, the problem of identifiability of these models is still at a nascent stage. In this paper, we propose an approach to verify the identifiability of unknown parameters for LPV or quasi-LPV state-space models. It makes use of a parity-space like formulation to eliminate the states of the model. The resulting input-output-parameter equation is analyzed to verify the identifiability of the original model or a subset of unknown parameters. This approach provides a framework for both continuous-time and discrete-time models and is illustrated through various examples.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2022, 32, 2; 255--269
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New fault tolerant control strategies for nonlinear Takagi-Sugeno systems
Autorzy:
Ichalal, D.
Marx, B.
Ragot, J.
Maquin, D.
Powiązania:
https://bibliotekanauki.pl/articles/331456.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
model Takagi-Sugeno
sterowanie tolerujące uszkodzenia
uszkodzenie równoczesne
estymacja stanu
twierdzenie Lapunowa
Takagi-Sugeno model
fault tolerant control
simultaneous fault
state estimation
Polya's theorem
Lyapunov theory
input to state stability
Opis:
New methodologies for Fault Tolerant Control (FTC) are proposed in order to compensate actuator faults in nonlinear systems. These approaches are based on the representation of the nonlinear system by a Takagi-Sugeno model. Two control laws are proposed requiring simultaneous estimation of the system states and of the occurring actuator faults. The first approach concerns the stabilization problem in the presence of actuator faults. In the second, the system state is forced to track a reference trajectory even in faulty situation. The control performance depends on the estimation quality; indeed, it is important to accurately and rapidly estimate the states and the faults. This task is then performed with an Adaptive Fast State and Fault Observer (AFSFO) for the first case, and a Proportional-Integral Observer (PIO) in the second. Stability conditions are established with Lyapunov theory and expressed in a Linear Matrix Inequality (LMI) formulation to ease the design of FTC. Furthermore, relaxed stability conditions are given with the use of Polya's theorem. Some simulation examples are given in order to illustrate the proposed approaches.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2012, 22, 1; 197-210
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear actuator fault estimation observer: an inverse system approach via a T-S fuzzy model
Autorzy:
Xu, D.
Jiang, B.
Shi, P.
Powiązania:
https://bibliotekanauki.pl/articles/331464.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
model rozmyty Takagi-Sugeno
obserwator ślizgowy
system odwrotny
actuator fault estimation
Takagi-Sugeno fuzzy models
robust sliding mode observer
inverse system method
Opis:
Based on a Takagi-Sugeno (T-S) fuzzy model and an inverse system method, this paper deals with the problem of actuator fault estimation for a class of nonlinear dynamic systems. Two different estimation strategies are developed. Firstly, T-S fuzzy models are used to describe nonlinear dynamic systems with an actuator fault. Then, a robust sliding mode observer is designed based on a T-S fuzzy model, and an inverse system method is used to estimate the actuator fault. Next, the second fault estimation strategy is developed. Compared with some existing techniques, such as adaptive and sliding mode methods, the one presented in this paper is easier to be implemented in practice. Finally, two numerical examples are given to demonstrate the efficiency of the proposed techniques.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2012, 22, 1; 183-196
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On-line parameter and delay estimation of continuous-time dynamic systems
Autorzy:
Kozłowski, J.
Kowalczuk, Z.
Powiązania:
https://bibliotekanauki.pl/articles/330669.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
delay system
continuous time model
discrete approximation
parameter estimation
least squares estimator
instrumental variable estimator
układ z opóźnieniem
aproksymacja dyskretna
estymacja parametrów
zmienna instrumentalna
Opis:
The problem of on-line identification of non-stationary delay systems is considered. The dynamics of supervised industrial processes are usually modeled by ordinary differential equations. Discrete-time mechanizations of continuous-time process models are implemented with the use of dedicated finite-horizon integrating filters. Least-squares and instrumental variable procedures mechanized in recursive forms are applied for simultaneous identification of input delay and spectral parameters of the system models. The performance of the proposed estimation algorithms is verified in an illustrative numerical simulation study.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2015, 25, 2; 223-232
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Probabilities of discrepancy between minima of cross-validation, Vapnik bounds and true risks
Autorzy:
Klęsk, P.
Powiązania:
https://bibliotekanauki.pl/articles/929593.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
estymacja regresji
walidacja krzyżowa
teoria uczenia się
generalizacja
teoria statystyczna
regression estimation
model comparison
complexity selection
cross-validation
generalization
statistical learning theory
generalization bounds
structural risk minimization
Opis:
Two known approaches to complexity selection are taken under consideration: n-fold cross-validation and structural risk minimization. Obviously, in either approach, a discrepancy between the indicated optimal complexity (indicated as the minimum of a generalization error estimate or a bound) and the genuine minimum of unknown true risks is possible. In the paper, this problem is posed in a novel quantitative way. We state and prove theorems demonstrating how one can calculate pessimistic probabilities of discrepancy between these minima for given for given conditions of an experiment. The probabilities are calculated in terms of all relevant constants: the sample size, the number of cross-validation folds, the capacity of the set of approximating functions and bounds on this set. We report experiments carried out to validate the results.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2010, 20, 3; 525-544
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-15 z 15

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