PARAMETRIC IDENTIFICATION OF MATHEMATICAL MODELS OF CHEMICAL KINETICS

2017 ◽  
Keyword(s):  
Mathematical Models ◽  
Chemical Kinetics ◽  
Parametric Identification

scholarly journals ANALYSIS OF INPUT INFLUENCING FACTORS AND SELECTION OF THE TYPE OF A MATHEMATICAL MODEL AT THE STAGES OF THEIR STRUCTURAL AND PARAMETRIC IDENTIFICATION FOR STUDYING DEFORMATION STATE OF THE SAYANO-SHUSHENSKAYA HPP DAM IN 2013-2016

2020 ◽  
Vol 25 (3) ◽  
pp. 53-62
Author(s):  
Natalia N. Kobeleva ◽  
◽  
Valery S. Khoroshilov ◽  
Keyword(s):  
Mathematical Models ◽  
Influencing Factors ◽  
Hydroelectric Power Plant ◽  
Parametric Identification ◽  
Field Observations ◽  
Hydroelectric Power ◽  
Cold Temperatures ◽  
Deformation State ◽  
Forecast Models ◽  
Structural And Parametric Identification

Assessment of the operational state of a hydraulic structure and its technical safety should be carried out by comparing the obtained quantitative and qualitative diagnostic indicators with their criteria values. For this purpose, predictive mathematical models of the structure's behavior should be developed, which are recommended to be calibrated according to field observations. The article considers features of constructing predictive mathematical models for studying deformation process of displacements of the dam crest of the Sayano-Shushenskaya hydroelectric power plant. For various combinations of input influencing factors, including the results of field observations and calculated values of component displacements, the most successfully designed predictive mathematical models were studied, on the basis of which the dam body points were forecasted for stages of its operation in different times. The advantages of using the created forecast models for various temperature conditions of the structure (medium, warm and cold temperatures of year) are presented.

scholarly journals A Math Approach with Brief Cases towards Reducing Computational and Time Complexity in the Industrial Systems

2020 ◽  
Author(s):  
Yaroslav Matviychuk ◽  
Tomáš Peráček ◽  
Natalya Shakhovska
Keyword(s):  
Mathematical Models ◽  
Time Complexity ◽  
Order Reduction ◽  
Parametric Identification ◽  
Problem Area ◽  
Model Order ◽  
Industrial Systems ◽  
The Neural Network ◽  
Reduction Methods ◽  
The Given

The paper proposes a new principle of finding and removing elements of mathematical model, redundant in terms of parametric identification of the model. It allows reducing computational and time complexity of the applications built on the model. Especially this is important for AI based systems, systems based on IoT solutions, distributed systems etc. Besides, the complexity reduction allows increasing an accuracy of mathematical models implemented. Despite the model order reduction methods are well known, they are extremely depended however on the problem area. Thus, proposed reduction principles can be used in different areas, what is demonstrated in this paper. The proposed method for the reduction of mathematical models of dynamic systems allows also the assessment of the requirements for the parameters of the simulator elements to ensure the specified accuracy of dynamic similarity. Efficiency of the principle is shown on the ordinary differential equations and on the neural network model. The given examples demonstrate efficient normalizing properties of the reduction principle for the mathematical models in the form of neural networks.

scholarly journals A Parametric Identification Method of Human Gait Differences and its Application in Rehabilitation

2019 ◽  
Vol 9 (21) ◽  
pp. 4581 ◽  
Author(s):  
Gao ◽  
Cui ◽  
Ji ◽  
Wang ◽  
Hu ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Parametric Identification ◽  
Human Motion ◽  
Human Gait ◽  
Shape Parameters ◽  
Gait Characteristics ◽  
Normal Ranges ◽  
Angle Data ◽  
Motion Characteristic ◽  
Parametric Description

In order to understand the regularity of human motion, characteristic description is widely used in gait analysis. For completely expressing gait information and providing more concise indicators, parametric description is also particularly significant as a means of analysis. Therefore, in this paper, the mathematical models of gait curves based on the generalized extension-Bézier curve were investigated, of which the shape parameters were used as individual gait characteristics to distinguish whether the gait is normal or not and to assist in judging rehabilitation. To evaluate the models, angle data from three joints (hip, knee, and ankle) were recorded with motion capture system when participants (10 healthy males and 6 male patients with ankle fracture) were walking at comfortable velocity along a walkway. Then, the shape parameters of each subject were obtained by applying the mathematical models, and the parameter range of the normal group was further summarized. Through comparison, it could be found that most shape parameters of patients exceed the normal ranges in varying degrees, and are concentrated on specific parameters. The results can not only help to judge the recovery stages of patients but also figure out the corresponding abnormal postures, so as to provide guidance for rehabilitation training.

scholarly journals CREATION OF MATHEMATICAL MODELS FOR PARAMETRIC IDENTIFICATION DURING TESTS TO DETERMINE THE FUEL CONSUMPTION OF THE HELICOPTER WITH EXHAUST- HEAT SHIELDS

2021 ◽  
pp. 134-139
Author(s):  
I. Televnyi
Keyword(s):  
Mathematical Models ◽  
Fuel Consumption ◽  
Basic Result ◽  
Parametric Identification ◽  
Careful Consideration ◽  
Heat Shield ◽  
Exhaust Heat ◽  
Infra Red ◽  
Heat Shields ◽  
The Impact

With the increasing effectiveness of guided missile weapons, the problem of protecting helicopters from these means of destruction is becoming increasingly important. To date, the issue of assessing the protection of helicopters in tests of helicopter equipment are insufficiently developed and require more careful consideration. Therefore, the research of the protection of helicopters equipped with an integrated protection system against guided missiles with infra-red target seeker devices and the impact of exhaust-heat shields on the values of flight characteristics of the helicopter is quite relevant. The article researches the influence of exhaust-heat shields on the flight technical characteristics of helicopters, their change during the installation of exhaust-heat shields. The estimation of the change in geometric, mass and center characteristics of helicopters by the calculation method is given and the method determining the characteristics of fuel consumption by the calculation and experimental method is given. The methodology and results of experimental researches of flight technical characteristics of the helicopter with the established exhaust-heat shield are described. The basic result of the research is the study of existing methods for determining the impact of exhaust-heat shields on the flight characteristics of helicopters. Methods of parametric identification for determination of fuel consumption are worked out and the analysis of flight technical characteristics of the helicopter is developed. The fuel consumption of the helicopter with exhaust-heat shield is defined. Integrated assessment of the effectiveness of protection of helicopters from guided missiles with infra-red targeting device can be directly used in practice in test systems for the protection of upgraded and the latest models of helicopters. According to the results of research, mathematical models for determining the fuel consumption of a helicopter with exhaust-heat shields have been developed.

scholarly journals Identification of UAV model parameters from flight and computer experiment data

2021 ◽  
pp. 12-22
Author(s):  
Serhii Kochuk ◽  
Dinh Dong Nguyen ◽  
Artem Nikitin ◽  
Rafael Trujillo Torres
Keyword(s):  
Mathematical Models ◽  
Automatic Control ◽  
Control Systems ◽  
Transfer Functions ◽  
Parametric Identification ◽  
Model Parameters ◽  
Identification Methods ◽  
Automatic Control Systems ◽  
Dynamic Objects ◽  
Structural And Parametric Identification

The object of research in the article is various well-known approaches and methods of structural and parametric identification of dynamic controlled objects - unmanned aerial vehicles (UAVs). The subject of the research is the parameters of linear and nonlinear mathematical models of spatial and isolated movements, describing the dynamics and aerodynamic properties of the UAV and obtained both from the results of flight experiments and using computer object-oriented programs for 3-D UAV models. The goal is to obtain mathematical models of UAV flight dynamics in the form of differential equations or transfer functions, check them for reliability and the possibility of using them in problems of synthesis of algorithms for automatic control systems of UAVs. Tasks to be solved: evaluation of the analytical (parametric), direct (transient), as well as the identification method using the 3-D model of the control object. Methods used structural and parametric identification of dynamic objects; the determination of static and dynamic characteristics of mathematical models by the type of their transient process; the System Identification Toolbox package of the MatLab environment, the Flow Simulation subsystem of the SolidWorks software and the X-Plane software environment. The experimental parameters of UAV flights, as well as the results of modeling in three-dimensional environments, are the initial data for the identification of mathematical models. The following results were obtained: the possibility of analytical and computer identification of mathematical models by highly noisy parameters of the UAV flight was shown; the mathematical models of UAVs obtained after identification is reliable and adequately reproduce the dynamics of a real object. A comparative analysis of the considered UAV identification methods is conducted, their performance and efficiency are confirmed. Conclusions. The scientific novelty of the result obtained is as follows: good convergence, reliability and the possibility of using the considered identification methods for obtaining mathematical models of dynamic objects to synthesize algorithms for automatic control systems of UAVs is shown.

scholarly journals Identificación del modelo de un motor de DC mediante métodos gráficos y métodos paramétricos

2017 ◽  
Vol 4 (2) ◽  
Author(s):  
DIEGO VERDUGO ORMAZA ◽  
JEAN MATA QUEVEDO ◽  
CESAR CORONEL GONZALEZ ◽  
TRAJANO GONZALEZ REDROVAN
Keyword(s):  
Mathematical Models ◽  
Dynamic Systems ◽  
Selection Criteria ◽  
Parametric Identification ◽  
Model Structure ◽  
Parametric Methods ◽  
System Behavior ◽  
Generator System ◽  
Arx Model ◽  
Graphic Methods

Este artículo presenta el estudio para conseguir el modelo de un motor-generador (planta), se emplean métodos gráficos o paramétricos que nos servirán como herramientas para representar dicho sistema de forma matemática. Se han adquirido muestras a través de una DAQ del comportamiento del sistema ante un escalón y una señal PRBS, los datos obtenidos se procesaron a través del software MATLAB y el toolbox IDENT, donde por medio de  criterios de selección se obtiene un modelo ARX. Las técnicas estudiadas fueron: identificación paramétrica con la aplicación de una señal PRBS y estructura de modelo ARX e identificación no paramétrica con la aplicación de métodos gráficos. Luego se realiza una comparación entre los datos reales con los diferentes métodos aplicados y se obtiene que las respuestas son muy similares. La identificación de sistemas nos sirve para construir modelos matemáticos de sistemas dinámicos basándonos en los datos observados, con lo cual se tiene un conjunto de técnicas para levantar un proceso. Abstract This article presents the study to obtain the model of an engine-generator system (plant), we use graphical or parametric methods that will serve as tools to represent said system in a mathematical way. The signs were acquired through a DAQ system behavior before a step and PRBS signal, the data was processed through MATLAB software and IDENT toolbox, where through selection criteria described subsequently obtained an ARX model. The techniques studied were: parametric identification with the application of a PRBS signal and ARX model structure and non-parametric identification with the application of graphic methods. Then a comparison is made between the actual data with the different methods applied and it is obtained that the answers are very similar. The identification of systems serves to construct mathematical models of dynamic systems based on observed data, which has a set of techniques to build a process.    

scholarly journals Identification of a mathematical model for a single-shaft power-generating GTE

Energetika ◽  
2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Anatoly Tarelin ◽  
Alexander Lyutikov ◽  
Iryna Annopolska
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Gas Turbine ◽  
Parametric Identification ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Variable Parameters ◽  
Operating Modes ◽  
Model Linearization ◽  
The Mathematical Model

The design and development processes of gas turbine engines rely on the usage of mathematical models representing the physics of engine functioning processes. One way of increasing the validity of a mathematical model is its identification based on engine test results. The identification of mathematical models of modern power-generating gas turbine engines (GTEs) presents a demanding and time-consuming task due to the necessity to identify the main controlled engine parameters determined in the course of experimental studies depending on a large number of the parameters that are not controlled during the experiment. In this regard the actual direction of reducing the labour intensity of the process of mathematical model identification is using identification program complexes. The object of the study was to solve the problem of structural-parametrical identification of the power-generating GTE functioning model detailing the turbine flow path calculations to the level of blade rows in order to obtain the GTE mathematical model that describes the characteristics of a real engine with given accuracy. To achieve the objective, the following problems were solved: variable parameters, controlled parameters and characteristics, ranges of their variations were selected from the total number of the mathematical model input data, the objective functions were defined; the task of the parametric identification according to the results of bench tests through GTE operating modes was performed; analytical approximating dependences for correcting coefficients (variable parameters) were obtained; structural-parametric identification of the mathematical model was performed. The novelty of the obtained results is the identification of the mathematical model of the nonlinear component GTE of the second level performed without model linearization (without its level lowering) by using the Optimum software packages. The methodological approach for the parametric identification of the mathematical model is proposed. This approach allows reducing the number of variable parameters under the modes lower that the maximum. It shows that the identified model allows obtaining the prediction results of the GTE parameters and characteristics through operating modes with a deviation of no more than 1.4% from the experimental data and, therefore, it will allow reduction of terms and an increase in the quality of power unit development.

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