Кафедра "Інтернет речей"

Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/5398

Увага! Поповнення колекції кафедри "Інтернет речей" – призупинено.

Від вересня 2022 року кафедри "Інтернет речей" та "Мультимедійних інформаційних технологій і систем" об’єднані у кафедру "Мультимедійні та інтернет технології і системи".

Первісна назва кафедри – "Розподілені інформаційні системи і хмарні технології".

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Analysis of Dynamic Stresses during Acceleration and Deceleration of a Conveyor Belt (Maxwell Element Model)
(2021) Pihnastyi, O. M.; Kozhevnikov, G. K.; Vasyuchenko, Pavel
The wave equation which allows researching the occurrence and the dynamic stress propagation in the conveyor belt is obtained for the conveyor belt, the material of which corresponds to the Maxwell element model. The boundary and initial conditions were written for power switching modes to consider the mechanical characteristics of the asynchronous engine with the phase rotor, which determine the dependencies between the traction torque and the rotational speed of an asynchronous electric engine with a phase rotor. The estimate is given to separate wave equation terms. The expression is obtained for the calculation propagation belt speed of the dynamic stress along the conveyor belt. The conditions are shown by which the wave equation will correspond to the model of Hooke’s element. By designing the dependencies between the traction torque and the rotational speed for a specified interval of the mechanical characteristic, the linear approximation is used. It is shown that the change of the material flow value coming into a section input doesn’t render a special influence on the dynamic stresses propagation process along the conveyor belt. The expressions are obtained for the dynamic stress propagation speed calculation. By deriving the wave equation it is assumed the uneven material distribution along the conveyor section.
Maxwell-Element Model for Describing Conveyor Belt Stresses
(2021) Pihnastyi, O. M.; Kozhevnikov, G. K.; Ivanovska, O. V.
The wave equation which allows researching the occurrence and the dynamic stress propagation in the conveyor belt is obtained for the conveyor belt, the material of which corresponds to the Maxwell element model. The boundary and initial conditions were written for power switching modes to consider the mechanical characteristics of the asynchronous engine with the phase rotor, which determine the dependencies between the traction torque and the rotational speed of an asynchronous electric engine with a phase rotor. The estimate is given to separate wave equation terms. The expression is obtained for the calculation propagation belt speed of the dynamic stress along the conveyor belt. The conditions are shown by which the wave equation will correspond to the model of Hooke’s element. By designing the dependencies between the traction torque and the rotational speed for a specified interval of the mechanical characteristic, linear approximation is used. It is shown that the change of the material flow value coming into a section input doesn’t render a special influence on the dynamic stresses' propagation process along the conveyor belt. The expressions are obtained for dynamic stress propagation speed calculation. By deriving the wave equation, it is assumed the uneven material distribution along the conveyor section
Analysis of dynamic mechanic belt stresses of the magistral conveyor
(2020) Pihnastyi, O. M.; Khodusov, Valery; Kozhevnikov, G. K.; Bondarenko, Tetiana
Controlling the amount of material flow coming from the input accumulate bunker to the input of the conveyor line and controlling the speed of the conveyor belt are common ways to reduce the energy consumption of the transport system. However, most works do not take into account transients associated with a change in the speed of the conveyor belt or a change in the input material flow. As a result of transient processes, acceleration or deceleration of the conveyor belt occurs, and as a result, dynamic stresses arise in the conveyor belt, which can exceed the permissible values. This article examines the dynamic stresses that occur during transient modes. When constructing a model of dynamic stresses, Hooke's law was used. The model of resistance to movement of the conveyor belt is adopted in accordance with DIN 22101: 2002-08. The analysis of the propagation of waves of dynamic stresses in the conveyor belt has been done. The formation of dynamic stresses as a result of the addition of the forward and backward waves is considered.
The dynamic model of conveyor belt stresses
(2020) Khodusov, V. D.; Pihnastyi, O. M.; Kozhevnikov, G. K.
The article considers the causes of dynamic stress when moving a conveyor belt with a material. The main factors of the occurrence of the dynamic resistance in the conveyor system are defined. It is demonstrated what the propagation speed of perturbations substantially depends on the loading level of the conveyor system with the material. When constructing a model of dynamic stresses, Hooke's law was used, which is an accurate approximation for most sol-id bodies, as long as the forces and deformations are small enough. The main attention in the article is given to the causes of dynamic stresses at the start of the conveyor system. When calculating the deformations, the inertia forces of the moving material and tape are taken into account. The analysis of the appearance of dynamic stresses at a constant value of the conveyor belt acceleration and the linear nature of the change in the value of the conveyor belt acceleration was carried out.
Effective Conveyor Belt Control Based on the Time-Of-Use Tariffs
(2020) Pihnastyi, O. M.; Kozhevnikov, G. K.
The paper proposes a method for constructing an algorithm for the speed control of a conveyor belt, based on the change in the price of electricity during the day. The analysis of methods for improving the energy efficiency of conveyor-type distributed transport systems is carried out. The influence of the uneven distribu-tion of material along the transportation route on the cost of transportation of a unit weight of the material is demonstrated. The advantages of using Time-Of-Use (TOU) tariffs when designing belt speed control systems for long conveyor systems are considered. The TOU periods with peak, standard and low energy consumption depending on time are presented in detail, as well as the values of the tariff coefficients for the TOU periods. The dependence of the value of the tariff coefficient on time is an essential factor that must be taken into account when designing control algorithms. When developing the control algorithm, it was assumed that the resistance to motion in accordance with DIN 22101 is de-termined on the basis of the primary friction coefficients. To describe a separate section, an analytical model of the conveyor in a dimensionless form was used. The problem of constructing an optimal algorithm for controlling the speed of a conveyor belt for a steady-state is formulated. The criterion of the quality of the control process in the conditions of using a constant amount of electricity during the day has been determined. The Pontryagin function and the conjugate system of equations are written, taking into account the uneven distribution of material along the transport route.
Kelvin-Voigt Model of Dynamic Stress in the Conveyors’ Belt
(2020) Pihnastyi, O. M.; Kozhevnikov, G. K.
The paper considers the reasons for the occurrence of dynamic stresses in a conveyor belt made of composite materials, the properties of which can be described by the Kelvin-Voigt model of an elastic element. A boundary value problem for the equation of elastic vibrations in a lightly loaded conveyor-type transport system is formulated. The dependencies determining the forces of resistance to the movement of the belt correspond to the recommendations of DIN 22101: 2002-08. An expression is presented that determines the speed of propagation of disturbances in the conveyor belt, taking into account the uneven distribution of material along the transport route. The reasons for the appearance of elastic stresses in the conveyor belt associated with the start, acceleration, deceleration and stop of the transport conveyor are demonstrated. Dimensionless parameters were introduced to analyze the causes of dynamic stresses in the conveyor belt. Similarity criteria in the dimensionless transport conveyor model make it possible to use the results obtained for similar transport systems. It is shown that the value of static stresses for lightly loaded transport systems is characterized by a linear dependence on the distance between the belt element and the drive shaft of the conveyor section. The solution of the boundary value problem defining the expression for dynamic stresses in the tape is presented. It is shown that the decay speed of the arising disturbances is inversely proportional to the value of the viscosity coefficient of the composite material, which characterizes the mechanical properties of the conveyor belt. A qualitative assessment has been made for the characteristic decay time of dynamic disturbances in a conveyor belt.
An Analytical Method for Generating a Data Set for a Neural Model of a Conveyor Line
(Institute of Electrical and Electronics Engineers, Inc., USA, 2020) Pihnastyi, O. M.; Kozhevnikov, G. K.; Bondarenko, Tetiana
Models using neural networks are a rather promising class of models for designing highly efficient control systems for a dynamic distributed transport system of the conveyor type. An important problem in constructing a model of a conveyor-type transport multi-section system is the formation of a data set for training a neural network. This study discusses a method for generating data for training a neural network based on an analytical model of a conveyor-type transport system. A detailed analysis of the most common models of the transport conveyor is performed and the choice of an analytical model for the formation of a training data set is theoretically justified. An algorithm for calculating the flow parameters of individual sections of the transport system is proposed. An estimation of the transition period is given. Graphical representation of a data set for training a neural network using an analytical model of a transport system is demonstrated.
Conveyor Model with Input and Output Accumulating Bunker
(Institute of Electrical and Electronics Engineers, Inc., USA, 2020) Pihnastyi, O. M.; Kozhevnikov, G. K.; Khodusov, V. D.
In this article, a model of a conveyor-type transport system with an input and output bunker is developed. The transport conveyor is presented in the form of a dynamic distributed system. It is shown that the material flow is proportional to the linear density of material distribution along the transport route. The coefficient of proportionality is the speed of the belt. When constructing the model, the assumption of the absence of oscillatory processes associated with the tension of the conveyor belt is introduced, which corresponds to the case when the function determining the speed of the belt is only a function of time. A solution is given, that determines the state of the flow parameters of the conveyor section for a given point of the transport route at an arbitrary point in time. It is shown that the state of the flow parameters for an arbitrary place in the transport route is determined by the state of the flow parameters at the input of the conveyor section, considering the transport delay. An expression is written that allows to calculate the amount of transport delay. The relationship of the transport delay value with the algorithm for controlling the conveyor belt speed is demonstrated. A system of equations for the model of a conveyor-type transport system with an input and output bunker is obtained. The behavior of the model for several characteristic cases of the functioning of the transport system is analyzed. The constructed model of the control object can be used to design highly efficient control systems for the flow parameters of the transport system with an input and an output bunker.
The information controlling model transport system during transient conditions
(Institute of Electrical and Electronics Engineers, Inc., USA, 2019) Pihnastyi, O. M.; Kozhevnikov, G. K.; Bondarenko, Tetiana
This article is devoted to designing an information management system for the conveyor line of mining enterprises. The analytical design method for the transient mode of the stepped speed control system of the conveyor line was developed. The partial differential equation was used in constructing the conveyor line model. The description of the production system is fulfilled in the single step approximation. A decision was obtained which determines the state of the parameters of the production line for a technological position specified as a function of time. Has been determined the length of the transition period during which the initial condition for the distribution of labour objects along the conveyor affects the parameters of the state of the conveyor line. The method for calculating the current parameters of a conveyor line with the use of partial differential equations allows the design of control systems for production lines of conveyor type for transient modes. The originality of the results obtained is to improve the PDE-models of the conveyor-type production systems used to design highly efficient production control systems operating in transient modes.
Методичні вказівки по організації і плануванню самостійної роботи з дисципліни "Оптимізація систем моніторингу"
(2019) Кожевніков, Георгій Костянтинович; Пігнастий, Олег Михайлович