ABSTRACT. Artificial intelligence for decision making, beyond conciousness and ethics

ABSTRACT. This paper is concerned with control of large gantry cranes possessing flexible structural vibrations in the direction of trolley travel. Since these vibrations are mainly caused by the movement of the trolley itself, they can be actively damped by a redesign of the trolley motion control system. In this contribution, a data-driven control approach based on the Koopman operator is proposed and validated on simulations.

ABSTRACT. Usage of the computational intelligence to create algorithms of the statistical model that describes the electrophysical processes at the last stage of the the lightning leader channel movement to the ground, taking into account the possibility of propagation of a counter spark from ground objects has been proposed. This model is based on experimental data on the speed of the lightning leader channel, the electric field strengths necessary for the development of leader channels of negative and positive polarity, etc. The correspondence of this model to the considered processes is confirmed by comparing the results of calculation the probabilities of places destruction by high-voltage discharge of the earth and objects located on it with known experimental data. An example of the model implementation for appreciation of the prognosticated lightning strikes to an object of the critical infrastructure, namely tanks for oil storage, has been presented.

ABSTRACT. Integration United Energy System of Ukraine to continental european energy system ENTSO-E

ABSTRACT. Purpose. The aim of this work is to compare the effectiveness of various methods for correcting cell failures in cascade high voltage frequency converters. These methods provide the smallest voltage drop on the motor, the least loads and oscillation of electromagnetic torque in an accident modes, and evaluate the effectiveness of pulse width modulation (PWM) methods with the injection of third harmonic and space-vector PWM in normal and emergency modes. Methodology. We use mathematical and geometrical interpretation of all analysed methods – Sinusoidal PWM (SPWM), Balanced sinusoidal PWM (BSPWM), Balanced PWM with injected 3rd harmonic (THPWM) and Balanced Space Vector PWM (SVPWM). Results. The method of balancing the phase-to-phase voltages by to such a shift of the zero point and rotation of the phase vectors, in which the amplitude of the phase-to-phase voltage decreases to the minimum possible value. Injection of the 3rd harmonic allows you to further increase the utilisation factor of power supplies in terms of voltage. But the violation of the symmetry of the phase voltages leads to the need to reduce the voltage amplitude to exclude saturation of the power supplies, which reduces this coefficient compared to the theoretically possible 15.6%. A distinctive feature of the method of balanced Space Vector PWM is that the amplitude of the 1st harmonic is always greater than the radius of the circle by 15.6%. Comparison of methods of space vector PWM (SVPWM), balancing of phase-to-phase voltage with the injection of the 3rd harmonic (THPWM) with sinusoidal PWM shows that SVPWM is the best method. Despite the more complex mathematical software for the implementation of this method, it provides the best performance in all considered emergency modes of 3…6 cascade converters. The Table of indicators for all methods are presented in the article. The use of a balanced SVPWM in combination with field oriented control makes it possible to obtain an electric drive in which, in the event of an accident, there are practically no shock mechanical and electromagnetic processes. After damage of cells the currents, electromagnetic torque and motor speed change along the required trajectory.

ABSTRACT. Moisture content takes a special place among food quality factors as a parameter that changes during the processes of storage and processing, and, in many cases, determines consumer properties of different food products. Modern grain moisture meters’ uncertainty is restricted to not more than 3 % of relative full scale error. Main task of the research is to receive robust linear static function for the grain moisture meter with four capacitive sensors. Robustness of new static function had been checked with a help of dispersion analysis. It was possible to conclude that values of repeatability and adequacy dispersions for new linear static function are approximately three times smaller, so as F-test values are seven times smaller in comparison with initial static function of a moisture meter, what proves its’ better robust properties

ABSTRACT. The paper considers the solution of the scientific and practical problem of assessing the accuracy and stability of the sensors working as part of the microprocessor control system for the parameters of the microclimate of an artificial ecosystem by using statistical methods for analyzing measurement results using the example of a temperature sensor. The importance of this task lies in the fact that the organization of accurate control of the parameters of the microclimate will ensure optimal climatic conditions for the development of plants and fish, and create an environment as similar as possible to the natural one by timely control of parameters and a quick reaction to the output of parameters at critical values. For the analysis, three series of measurement results of the control indicator (water temperature) were used. The analysis confirmed the hypothesis that there are no violations of the stability of the temperature sensor, which makes it possible to recognize the metrological sensor as reliable. It is proved that the problems of increasing the likelihood of controlling objects with stochastic parameters, and controlling their metrological reliability are relevant and are important for the development of the theory and practice of non-dismantling control.

ABSTRACT. The technology of limiting the magnitude of the magnetostatic field created by the electronic components of the spacecraft is considered. The incorrectness of the methods based on the multidipole model of the magnetic moment for modeling the magnetic hindrance of the microsatellite components is established. It is proposed to use a limited number of experimentally determined spherical harmonics of the magnetic field created by each electronic unit for modeling and calculating the magnetic induction of hindrance. The practical possibility of controlling the number and location of magnetic sources inside the spacecraft is shown.

ABSTRACT. Abstract — The results of a study of the operating conditions of the main power equipment of a three-phase combined compensation rectifier are presented. Due to the novelty of the circuit and the complexity of electromagnetic processes, the study was carried out without taking into account the inductance of the AC circuit. The dynamics of changes in the value of currents and voltages of the equipment depending on the value of the turn-on delay of the commutating link transistors is analyzed. Conclusions are drawn about the advantages of the proposed circuit implementation of the converter, implemented according to the three-phase combined compensation circuit, in comparison with the compensation converters of the previous generation.

ABSTRACT. Abstract —The paper presents the results of a study of commutating processes in a three-phase combined compensation rectifier. It is shown that based on the features of the circuit design, in the investigated rectifier, during one the frequency period of the supplying network voltage, there are four switching processes. One is the switching of the power electrical diodes of the non-compensation part of the rectifier. The other three commutating processes take place in the power valves of the compensation part. They are related both to switching between the power valves of different phases and to switching between the power valves of the same phase. The research methodology is based on solving systems of differential equations.

ABSTRACT. A study was made of the performance of a bridge inverter with complementary forms of non-sinusoidal half-bridge voltages with a combined form of modulation. The bridge inverter is characterized by a wide range of regulation of the output sinusoidal voltage, compliance with the requirements for power quality in terms of spectral composition, ease of formation of the modulation law and the functionality of changing the type of modulation. The influence of the ratio of the components of the combined type of modulation on the level of common-mode interference is studied and the conditions for achieving the smallest value are determined. Comparative estimates of the power of dynamic losses in the switching elements of the inverter and the power of circulation are obtained for combined and traditional types of modulation.

ABSTRACT. This paper illustrates the application of averaging method based on Lagrange theorems for analysis and calculation of SEPIC converter operating in continuous conduction mode of reactive storage elements. It is shown that this method simplifies the calculation of converter by reducing the number of calculations and avoiding cumbersome intermediate transformations. A mathematical model has been developed that reflects the relationship between the parameters of SEPIC converter and the convenient analytical relationships for calculating the constant and pulsating components of converter processes are obtained. Based on them, expressions for calculating the boundaries of continuous conduction modes of reactive storage elements, as well as the maximum currents and voltages in the switching elements and other parameters of SEPIC converter are developed. The obtained analytical relations allow to apply the methods of mathematical analysis of quantitative and qualitative characteristics of processes, which helps to increase the efficiency of converter calculation at the stage of its design.

ABSTRACT. The subject matter of study in the article is schematic solutions of instrumentation amplifiers with a programmable gain applied for the digital processing systems, biomedical equipment, measuring instruments, data analysis systems, etc. The goal is the creation of the circuitry that implements a programmable instrumentation amplifier that combines the advantages of already-known solutions with the possibility of setting the necessary gain through a digital I2C / SPI interface. During the research, a new solution was proposed for a small-sized programmable instrumentation amplifier based on a differential amplifier with a fixed gain and programmable digital potentiometer.

ABSTRACT. In this paper, we developed a new synthesis of state feedback controllers for nonlinear discrete-time systems where time-varying delays are bounded. Using T-S fuzzy models, these controllers are applied based on a new design methodology to overcome the obstacle of bilinearity. The results of this methodology yields to a quite simple LMI condition that is numerically tractable employing many convex optimization algorithms. The effectiveness of our LMI-based design method is illustrated using some numerical examples. Namely, the proposed design approach is very useful comparing with those obtained in the literature.

ABSTRACT. The analysis of a stabilized DC converter operating on a plasma arc is carried out. The frequency characteristics of the input and output resistances and the transfer functions of the L-shaped LC filter loaded on the active resistance of the load are obtained.

ABSTRACT. The article analyzes the influence of the coupling coefficient of the transformer windings on the output characteristics of the resonant flyback converter intended for use in applications for the implementation of contactless power transmission. Expressions for the theoretical calculation of the dependences of the output characteristics of the converter on the coupling coefficient have been obtained. The coupling coefficient has been calculated for the L-shaped transformer replacement circuit of the flyback resonant converter. A simulation experiment of the wireless capacitor charging using the flyback resonant converter has been carried out. Its results coincide with the theoretical ones. It has been established that during the flyback converter design, it is most appropriate to use an L-shaped transformer replacement circuit, which causes the difference between theoretical and experimental results within 2%.

ABSTRACT. The paper is devoted to application of implicit Euler algorithm for computer simulation of pulse-forming networks. In the previous paper, the authors proposed to use a computer model based on explicit Euler algorithm to optimise performance of a modified pulse-forming network with the damping resistor connected in parallel to the first inductance of the network. Although the research showed very good characteristics of the proposed pulse-forming network, it is well-known from the literature that computer models based on explicit Euler algorithms can accumulate errors, what can undermine the validity of the obtained results. To verify and confirm performance of the computer simulation model used previously, authors designed a computer simulation model based on implicit Euler algorithm, which is free from this accumulation of errors. Developed computer simulation model with implicit Euler algorithm has confirmed the previous results obtained with explicit Euler algorithm and, although it requires more calculations, it gives a range of options for the researchers. These possibilities include testing other models in the absence of the analytical solutions or using this model when an added accuracy of the simulation is necessary. Designed computer simulation model with implicit Euler algorithm can be used in pulse-forming networks design and improvements.

ABSTRACT. This paper presents analysis and comparison of three variants of the modified scheme and techniques of spacevector-based synchronous pulsewidth modulation (PWM), applied for control of three diode clamped inverters of transformerbased photovoltaic (PV) installation, and focused on assuring of the symmetry of winding voltage of power transformer during the whole control diapason. Power supply of inverters is insuring by the corresponding three solar strings consisting of a set of PV panels, and the outputs of three inverters are connected specifically with inverter-side windings of multi-winding grid-tired transformer. Results of simulation prove the fact of advanced spectral composition of the winding voltage of PV installation with triple inverters regulated by algorithms of synchronous space-vector PWM, assuring potential reduction of losses in these systems.

ABSTRACT. Problems of automated electric drive. Theory and practice

ABSTRACT. The result of the study is the justification of the possibility of using the Park vector method to diagnose the presence of asymmetric modes in the drive of an electric locomotive with vector control of induction motors. As a result of simulation it is established that at the symmetry of motor stator windings and supply voltages the Park vector hodograph describes the correct circle, while at asynchronous stator winding asymmetry, or supply voltage vector asymmetry the Park vector hodograph describes an ellipse. Moreover, when the stator windings are asymmetric, the angle of inclination of the ellipse is equal to zero, and the angle of ellipticity decreases with an increasing degree of damage to the windings. The asymmetry of the supply voltage system causes a change in both the angle of inclination of the ellipse and the angle of ellipticity. To identify possible asymmetric modes in the stator windings of the traction motor with asymmetry of supply voltages, an algorithm for recalculating the parameters of the Park vector for the conditions of symmetry of supply voltages is proposed. The structure of the system for diagnosing the presence of asymmetric modes in the elements of the traction drive system of an electric locomotive has been developed.

ABSTRACT. PWM-controlled power stage under several conditions are prone to the coexistence of several stable modes for the same set of parameters. For the majority of applications, it is an undesired behavior; the other modes apart from the “nominal” one are characterized by lower efficiency and should be avoided. We propose a control aiming to suppress the coexisting undesired modes by utilizing periodic sinusoidal modulation of a reference signal. We study the efficacy of the proposed control strategy for different modulation strength levels with a chopper-fed DC drive as the case example of a PWM-driven system exhibiting multistability. The study is performed by means of numerical simulations in the time domain and bifurcation diagrams. The possible pitfalls and features of the proposed control are demonstrated.

ABSTRACT. This paper describes the results of a study of the dynamics of the electric drive with the cyclic action of a flying saw of an electric pipe welding mill. Options for improving the dynamic performance of this electric drive are considered. The proposed options for improving the dynamics of the mechanism of cyclic action provide a reduction in the position error of the mechanism in transient and stationary modes of operation.

ABSTRACT. The aim of the work is to develop and study the system of automatic voltage stabilization of a three-phase magnetoelectric generator with shunting of the magnetic flux in the conditions of change of rotation speed. The magnetoelectric generator is intended for use in autonomous installations of small generation of the electric power. The generator is created on the basis of the serial induction electric motor that provides economy of production of a power source. The operating characteristics of the experimental sample of the magnetoelectric generator are presented, which show the possibility of voltage control. A mathematical model of a magnetoelectric generator with magnetic flux shunting in the rotor coordinate system is presented. The system of automatic voltage stabilization of a three-phase magnetoelectric generator with magnetic flux shunting in the conditions of robot speed change is considered in the work. The voltage of the generator is controlled by changing the magnetic flux of the working area using the current of the stationary winding of the shunt, powered by direct current. Algorithms for controlling the shunt current and generator voltage based on the method of inverse dynamics problems in combination with the minimization of local functional capabilities of instantaneous energy values are a scientific novelty, providing dynamic decomposition of the system and low sensitivity to parameter changes. The developed control system provides astatic voltage regulation. The quality of generator voltage control when changing the rotor speed within ± 15% of the nominal value was studied.

ABSTRACT. The considers of the creation and research of three-phase magnetoelectric generators with magnetic flux shunting based on serial asynchronous electric motors. This allows you to control the voltage of the generator by changing the current in the stationary electrical winding of the shunt, which is powered by direct current. The operating characteristics of the experimental sample of the magnetoelectric generator are presented, which show the possibility of voltage control. A three-dimensional field mathematical model of the generator has been developed, which allows to perform electromagnetic calculations of the generator with the set parameters taking into account the influence of finite effects, magnetic scattering fields and their radial-axial nature.

ABSTRACT. A study of high-voltage pulse discharge in an exothermic compound as a control object was made. The rules for finding the initial conditions of the control algorithm were proposed. The correlation analysis of relationship between electrodynamic and hydrodynamic characteristics was done and hence the information coordinates were defined. The algorithm for controlling a high-voltage pulse discharge in an exothermic compound has been developed

ABSTRACT. The multi-step process of structural-parametric identification of mathematical models of control objects according to the principle of rational complication is considered. Identification specifies the mathematical model of the object and methods of its identification in the process of accumulation of a posteriori information. The quality of multi-step structural and parametric identification of an object depends on the amount of a priori information that grows after conducting experimental studies. For a qualitative solution to the problem, it is necessary to rationally complicate identification methods after analyzing the results of the previous identification step. Examples of application of the proposed principle of rational complication are given, which show its advantages in comparison with classical methods.

ABSTRACT. This article presents approach to integrate algorithms of computer vision to control system of traction electric drives in rail transport. Shows how to use computer vision algorithms to calculate line velocity instead of other sensors such as wheel odometers, GPS, DGPS and inertial sensors that do not work on slippery surfaces and at low speeds. Therefore, this article deals with the application of linear velocity as feedback in the control system to optimize power consumption at the start and stop and to eliminate wheel slip. System of control of electric drive implemented and tested by robotics platform. Shown the process of development robotics platform that uses for imitation dynamic modes behavior in real situations for rail transports.

ABSTRACT. Positioning systems are subject to conflicting requirements of optimality in terms of speed and the absence of overshoots. The problem of their simultaneous execution is solved in this paper for sliding mode control systems. An effective means of synthesizing such systems is the N–i switching method. The simplicity of his mathematical apparatus made it possible to provide aperiodization of sliding modes in third-order optimal control systems for typical displacement modes under intermediate coordinate constraints. The result was achieved by modifying the basic version of the method and substantiated by the analysis of the slip equation. The solution of the problem is illustrated by numerical examples and simulation results.

ABSTRACT. In the article, the authors consider the electromagnetic transducer for multiparameter non-destructive testing of metal cylinders. The publications review shows that the task of monitoring the stress-strain state of cylindrical metal elements of machinery is relevant. The detection of such a state is carried out by measuring the electrophysical parameters of these cylinders. It is shown that these parameters are arguments of the functions of the magnetic flux density vector components, which are considered in a 2D cylindrical coordinate system. A distribution of the tangential and radial components of the electromagnetic field in the space surrounding the tested object is obtained. The zones of the non-informative output signal of the measuring coils are determined for the case of their placement on a circle of a fixed radius. Such zones are also defined when normalized signals are used.

ABSTRACT. The effectiveness of mobile robots when operating in unknown, cluttered terrain requires fast and accurate detection of the slightest obstacles that can interfere with the robot movement. The present paper is a continuation of research on improving the robot Laser Technical Vision System. Using Particle Swarm Optimization Algorithm performed an optimal tuning of the proportional-derivative controller parameters for the DC motor of a laser positioning system to improve the positioning speed. It is shown, that the resulting controller is robust, i.e. has a weak sensitivity to the parametric uncertainties of the motor model.

ABSTRACT. Stochastic robust control by the electromechanical servo systems under non-Gaussian random external disturbances based on the anisotropic theory of stochastic robust control was synthesized. The solution of the problem of synthesis of an anisotropic optimal controller in the state space is based on the solution of three cross-coupled algebraic Riccati equations, the Lyapunov algebraic equation and the equation with respect to the logarithm of the determinant of a positive definite matrix. The results of modeling and experimental studies of stochastic robust two-mass electromechanical servo systems under non-Gaussian random external disturbances are given. With the help of synthesized robust stochastic controllers, it is possible to improve of quality indicators of two-mass ectromechanical servo system in comparison with the system with standard regulators that it is established based on the results of modeling and experimental studies.

ABSTRACT. There is a steady trend in the mechanical engineering industry to increase the required accuracy of parts manufacturing using high-speed equipment. The control of such equipment requires consideration of the motion differential characteristics such as velocity, acceleration, and jerk. However, due to the discrete nature of the incremental encoder operating as a pulse generator, estimation of these characteristics requires the use of special data processing methods. Considered encoder resolution limitations and proposed a method for determining the discreteness providing the maximum possible accuracy of position measurement. Discussed methods of velocity estimation using incremental encoders. Determined the required sampling frequency of the time counter. The use of CNC-based software and hardware complex for the study of the velocity estimation methods is proposed. Results of experimental investigations confirm the possibility of acceleration estimation and demonstrate problems with jerk estimation. Analysis of the error sources in the measurement of differential characteristics is performed. Topical areas for further research is proposed.