Program of section Modelling, simulation

Lectures

RefNr: 12 (Review state=accepted_lecture)

Dr.Jalal M. Abdallah & Dr. Abdallah R. Al-Thaimer:
The effect of homogeneity in the electrical networks
Presenters: None.
Abstract

This Paper presents a technique for analyzing the effect of homogeneity in the electrical networks and investigates the relationship between this characteristic of electrical network and active power total losses, as the criteria of optimality. Optimizing electrical network operation modes are introduced in loops by realization of optimum transformation ratios of transformers.

RefNr: 36 (Review state=accepted_lecture)

Marius Constantin POPESCU and Anca PETRIŞOR:
NEURO-FUZZY CONTROL OF INDUCTION DRIVINGS
Presenters: None.
Abstract

The paper presents the possibility to control the induction drivings using fuzzy and neural systems. A three-phase induction motor is controlled using a vectorial control and fuzzy logic controllers with three and five linguistic labels. It is realized an analogy between a PI controller and a neuro-fuzzy controller. The simulations using such of controllers highlighted the advantages of using a fuzzy controller: increasing responding time of induction motor speed and respectively the stator current limitation of the used induction motor.

RefNr: 52 (Review state=accepted_lecture)

Cătălin Sorin UNGUREANU and Irina COZMÎNCĂ:
ELECTRO-CHEMICAL GRINDING PROCESS MATHEMATICAL MODEL BASED ON ENERGETICALLY PARAMETERS
Presenters: Ungureanu, Catalin Sorin
Abstract

The electro-chemical grinding process is intended for hard and extra hard materials used to build up metal cutting or bending tools. The complexity of this technological process results from its components, i.e. mechanical grinding, anodic dissolution and electrical erosion, determining thus a great number of input and output parameters. As input parameters the supply voltage, the contact pressure between worked piece and the abrasive electrode disk, the disk speed, the longitudinal feed or the contact surface height are used. The intensity of the current absorbed by the electrochemical cell, the electric power consumed by the electric motor of the main motion kinematical chain, the process productivity, the relative wear of the abrasive electrode disk, the worked surface roughness and the edges rounding radius are considered as output parameters. The paper presents a study of the influences exerted by the above-mentioned input parameters on energetically output ones, i.e. the current intensity absorbed by the electrochemical cell and the electrical power consumed by the main motion engine. For parameters measurement, we used a Keithley Metrabyte data acquisition system based on a DAS-1600 board; a MB02 backplane and MB input modules for signal conditioning. The programmed experiments method developed in C++ medium was applied in order to determine the values of the constants and exponents in relations . The mathematical equations established were validated by Student and Fisher tests and represented in 2D and 3D coordinates using MATLAB medium.

RefNr: 54 (Review state=accepted_lecture)

Drighiciu Mircea Adrian:
PETRI NET FORMALISM FOR A POSSIBLE HIERARCHICAL STRUCTURE OF COMPLEX HYBRID SYSTEMS
Presenters: Drighiciu, Mircea Adrian
Abstract

A hybrid system may be considered as a structure, which involve both continuous, and discrete variables. Often, the continuous dynamic is represented by differential – algebraic equations; on the other hand, the discrete dynamic is modeled by automata or input – output transitions systems, with a finite and countable number of states. For the last past years, there has been a growing interest in dynamic systems that feature both continuous time and discrete event behaviors. In the meantime, the formalism of classic Petri nets, continuous and hybrid Petri nets and their numerous extensions, offer powerful concepts and formal techniques for expressing fundamental discrete events and continuous time behavior. The most approaches for hybrid systems representations are currently usable for small examples; models of complex systems are unwieldy. In this paper, we propose a hierarchical concept, based on hybrid Petri nets, and on object-oriented paradigm for complex systems design.

RefNr: 94 (Review state=accepted_lecture)

Liana CIPCIGAN, Mircea CHINDRIS, Adrian RUSU:
HARMONIC ANALYSIS OF CAPACITOR SWITCHING TRANSIENTS
Presenters: Cipcigan, Liana Mirela
Abstract

Disturbances such as capacitor switching transients and power systems harmonics have become an increasing concern for both electric utilities and customers. Among the various factors that affect power quality, those related to the transients originated from capacitor bank switching in the primary distribution systems must be highlighted. The paper presents an analysis of characteristics of the transients resulting from the energizing of utility capacitor banks along with the factors that influence their intensities. In addition, a spectral analysis of the current and voltage waves is presented. The procedure can reveal the harmonic component, which can affect the operation of control and protection equipment, as well as sensitive loads of the industry. For purposes of this study, a subsystem that represents a real 11kV distribution subsystem was simulated with PSCAD/EMTDC software package.

RefNr: 125 (Review state=accepted_lecture)

Bence Molnar and Lajos Somkutas:
Control loop modelling with a single IC
Presenters: Molnár, Bence
Abstract

As a result of our research work we have produced an electronic model for investigation of a control loop. With the aid of this model we can demonstrate the mutual relations between the transfer function, Bode plots and time responses.

RefNr: 139 (Review state=accepted_lecture)

Jerzy Cyklis, Jerzy Zajac, Adam Slota:
MODELLING COMPONETS OF FLEXIBLE ASSEMBLY SYSTEMS BY MEANS OF COLOURED OBJECT OBSERVABLE PETRI NETS
Presenters: None.
Abstract

In the paper Coloured Object Observable Petri Net COPN is used for modelling components (assembly stations, input/output buffers, means of transport) of Flexible Assembly System FAS. Model of an assembly station includes description of assembling different versions of a sub-assembly according to current orders. Model of the whole FAS is built by integration of the proposed components? models. The model can be used for simulation of FAS operation in a distributed environment. Using COPN as the modelling language enables observation system?s objects states and thus becomes useful for example for the sake of diagnostic procedures.

RefNr: 146 (Review state=accepted_lecture)

Florin Dragan:
INTERMITTENCY IN A CHAOTIC CURRENT MODE CONTROLLED BOOST CONVERTER
Presenters: Dragan, Florin
Abstract

The article analyzes the chaotic behavior based intermittency in a chaotic current mode controlled boost converter. The study implied theoretical considerations and simulations for this kind of converter based on bifurcations diagram. Intermittency occurs when a system’s behavior look to switch back and forth between two different behaviors without an important noise.

RefNr: 152 (Review state=accepted_lecture)

István Selek, Petra Aradi:
TIME OPTIMAL CONTROL OF A ,,BALL AND BEAM'' SYSTEM USING GENETIC ALGORITHMS
Presenters: Selek, István
Abstract

This article presents a solution of a time optimal control problem of a ,,Ball and Beam'' system. The dynamic behaviour of the simplest two degree of freedom mechanical model of a computer controlled balancer device was investigated. After observing the features of this autonomous mechanical system a time optimal control has been created for the device according to mathematical principles, however the results were generated numerically using the powerful optimalization method called genetic algorithms.

RefNr: 155 (Review state=accepted_lecture)

Ladislav KRAL, Miroslav SIMANDL, Pavel HERING, Jindrich DUNIK:
Kalman Filtering Based Methods for Identification of Nonlinear Systems by Neural Networks
Presenters: Král, Ladislav
Abstract

Identification of nonlinear system using neural networks and Kalman filtering based methods are treated. The stress is laid on networks parameters estimation, particularly by derivative-free Kalman filter based methods. The methods are easier for implementation because the Jacobian needed in standard methods as Extended Kalman Filters are not necessary to be evaluated. The derivative-free filters are compared with Extended Kalman filter, regarding especially estimation quality and numerical demands.

RefNr: 160 (Review state=accepted_lecture)

Károly Molnár, Gábor Péceli:
Overcomplete Representation of Sensor Network Data by Distributed System Modeling
Presenters: Péceli, Gábor
Abstract

This paper presents a technique for representing distributed data of sensor networks. The approach is based on a general distributed regression framework that models sensor data by fitting a global function to each of the local measurements. The presented method explores the possible extensions of this distributed regression, by using more complex signal representations. In order to reduce the amount of processed data and the required communication, the signal model has to be as compact as possible, with the ability to restore the arbitrary measurements. To achieve this, the regression is followed by a data compression step, where the basis function set is changed to an overcomplete set, as these have special advantages in cases of nonstationary signal modeling than complete base representations.

RefNr: 177 (Review state=accepted_lecture)

Kalinski Krzysztof:
THE OPTIMAL CONTROL AT ENERGY PERFORMANCE INDEX AS A RULE FOR VIBRATION SURVEILLANCE IN THE HYBRID SYSTEM BY ON EXAMPLE OF MILLING FLEXIBLE DETAILS
Presenters: Kalinski, Krzysztof
Abstract

The paper is devoted to vibration surveillance of unsteady systems, which are idealised by the finite element method. In order to reduce a level of vibration, external control command has been introduced. It is a special case of the active vibration control and the dynamics of controlled system with changing in time coefficients is described. Here is defined an algebraic performance index, whose values change with time. It comprises influence of kinetic and potential energies of vibration, and also control energy. Optimal control command is generated on?line, with presumed sample ratio. Thus, the formulation is better than ones based on an integral performance index. The other advantage is that the approach proposed does not require an examination of controllability and observability of the system. In a system with non?proportional damping we can separate modal subsystem, structural subsystem and subsystem connecting both of them. If we consider that only rheonomic?holonomic constraints are between generalised coordinates of modal and connecting subsystem, we will obtain description of whole controlled system?s dynamics in the hybrid co?ordinates (i.e. modal and generalised). Such approach allows on?line determination of optimal control command, and subsequently ? performance of control of non?stationary system. Using the hybrid co?ordinates description significantly reduces a size of controlled system. The latter is important from a point of view of practical applications of suggested mean of control in case of multi?degree?of?freedom systems. As illustrative example of the approach, time?domain vibration surveillance of ball end milling process is elaborated. Ball end milling of flexible details is observed very frequently in case of modern machining centres. Non-stationary calculation model of machining process has been performed. As result of modelling, we get a hybrid system in which are separated -modal subsystem. It is a stationary model of one-side-supported flexible plate, which displaces itself with desired feed speed; -structural subsystem, that is to say non-stationary discrete model of ball end mill (i.e. with given speed of revolution) and cutting process; -abstractive connective subsystem as conventional contact point between tool and workpiece. Here is evidenced usefulness of the hybrid system control for vibration surveillance of non-stationary systems idealised discretely. A synthesis of control system of ball end milling of flexible details requires identification of parameters (i.e. natural frequencies and normal modes) of stationary modal subsystem. Because only first normal mode is important, suitable modal assurance criterion (MAC) has been assessed and confirmed good agreement between the results. Prospective research foresees computer simulation and performance of vibration surveillance during cutting process.

RefNr: 189 (Review state=accepted_lecture)

Tomá? SALOKY and Ján PITEĽ:
MODEL OF THE HEATING PROCESS CONTROL WITH OUTDOOR TEMPERATURE COMPENSATION
Presenters: None.
Abstract

Model of the heating process control with outdoor temperature compensation was designed for simulation. The heating system corresponding to the conventional central heating with water as heat transfer medium and supply water temperature regulation by mixing was chosen for design. The model was designed according to the chosen heating system flow-sheet and outdoor temperature compensation requirements. Dependence of the indoor temperature on controlling variable (heating curve) and on disturbance variable (outdoor temperature) was identified by model simulation.

RefNr: 220 (Review state=accepted_lecture)

Csaba Blága, Ernő Kovács:
MEASUREMENT OF SOLENOID BASED ACTUATORS
Presenters: Blága, Csaba
Abstract

An interesting field of interaction of different components of mechanic engineering and electronic engineering is given by electromechanical components those are actuated by solenoids.

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