Статті в журналах: "Cutting machines Design and construction Mathematical models"

1

Zastempowski, Marcin, Andrzej Bochat, Lubomir Hujo, Juraj Jablonicky, and Maciej Janiec. "Impact of Cutting Units’ Design on Biomass Cutting Resistance." Acta Mechanica et Automatica 16, no. 3 (September 1, 2022): 259–65. http://dx.doi.org/10.2478/ama-2022-0031.

Повний текст джерела

Анотація:

Abstract The paper presents mathematical models describing the moments of resistance to cutting on the cutting drum shafts in the biomass cutting process. The mathematical procedures described in the paper have been verified on a test stand developed and constructed by the authors, which reflects real conditions of the process of cutting plant material into pieces of specified lengths. Experimental verification proved that the developed mathematical models are adequate for drums of both cylindrical and conical constructions. The value of the average error did not exceed 13%. Following the mathematical elaboration and verification studies, the authors carried out calculations for machines currently available on the market that are equipped with drum cutting units. The calculations were carried out for the most commonly cut material, i.e. for maize, straw and green plant materials. The obtained results confirm the complexity of the problem arising from a wide range of numerical values of cutting resistance, which is contained in the range of 400–1,800 nm. The compiled database can be practically applied in the selection of machines for specific field works, and the mathematical models developed and verified in the study can be applied at the stage of designing new designs of cutting drums used in forage harvesters.

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Ismailova, N. Р., and T. M. Mohylianets. "ALGORITHMIC FORMATION OF CONNECTED MODELS FOR INFORMATION CONTROL SYSTEM IN DESIGNING KINEMATIC PAIRS." Проблеми створення, випробування, застосування та експлуатації складних інформаційних систем, no. 20 (November 26, 2021): 67–73. http://dx.doi.org/10.46972/2076-1546.2021.20.06.

Повний текст джерела

Анотація:

In modern systems for the automatic design of complex products for military equipment, algorithmic construction of conjugate models of curved surfaces using computer technologies that exclude interference are increasingly being used. This gives a powerful impetus to the development of applied geometry of surfaces and stimulates the search for new ways to improve the technological processes of manufacturing parts, on machines with an information control system. In particular, this applies to technological operations on numerically controlled machines. One of the main directions in modeling kinematic pairs should be considered the study and design of the shapes of surfaces in close connection with the operating conditions of structures in military equipment and weapons in which they are to be used. The shapes of complex curved surfaces affect the reliability and durability of mechanisms in military equipment and weapons and therefore require more careful consideration of external conditions when designing. Much attention is paid to the design of surfaces, taking into account an increasing number of predetermined requirements, conditions for the formation of curved surfaces of kinematic pairs in military equipment. The use of algorithmic constructions of conjugated kinematic pairs for an information control system in the manufacture of real surfaces of military equipment obtained as a result of stamping, the creation of a geometric model of stamping, reflecting a real physical process, is an urgent problem. In recent years, in the manufacture of precision high-quality products of kinematic pairs and cutting tools in military equipment and weapons, complex curved surfaces have been widely used, which require the development of a geometric and mathematical apparatus for their modeling. Algorithmic modeling of curvilinear transformations for the formation of mating surfaces of kinematic pairs in military equipment, based on a parametric kinematic screw, is proposed, which will eliminate interference during their manufacture.

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Fomin, Alexey. "The Synthesis, Designing and Analysis of the Spatial Mechanisms with Imposed Constraints." Applied Mechanics and Materials 756 (April 2015): 495–99. http://dx.doi.org/10.4028/www.scientific.net/amm.756.495.

Повний текст джерела

Анотація:

The present study provides structural synthesis, designing of 3D models and kinematic analysis of the developed spatial one-and two-movable mechanisms with imposed constraints. These mechanisms have an opportunity of technological application as mechanisms for cutting the complex internal surfaces of machine elements. The mechanisms produce a special kind of screw motion which is the most suitable means for cutting of complex spatial surfaces. Structural synthesis was based on mathematical solution of universal structural system where numbers of kinematic pairs and movable links were calculated. 3D-modelling analysis allowed to identify motion paths of their output links with machining tools. This investigation results gave an opportunity to analyze the tools motion, optimize their constructions and use of relevant parameters, and design their motions to obtain specified surfaces of machine elements.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Zastempowski, Marcin, Andrzej Bochat, and Lubomír Hujo. "Selected Aspects of Modelling and Design Calculations of Roller Mills." Sustainability 13, no. 5 (March 1, 2021): 2595. http://dx.doi.org/10.3390/su13052595.

Повний текст джерела

Анотація:

An analysis of construction was conducted in this study, and the guidelines for designing roller mills used commonly in the agri-food, chemical, power and construction industries were presented. Quick designing of the machines required existence of adequate mathematical models. Within the framework of the study’s realization, a mathematical model was developed and we presented the selected results of calculations of the milling rollers loading from the assembly’s mill bowl. The simulation calculations conducted with the mathematical model unambiguously show that the roller’s rotation around a fixed point considerably influences the total loading of the mill’s bowl, and passing over that phenomenon is a mistake.

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Smirnov, Yu M., B. M. Kenzhin, N. S. Smakova, and M. A. Zhurunova. "Optimized control over modes of hydraulic percussion cutting heads of mining machines." Mining informational and analytical bulletin, no. 6 (May 20, 2020): 95–104. http://dx.doi.org/10.25018/0236-1493-2020-6-0-95-104.

Повний текст джерела

Анотація:

The main cause of the disagreement between the actual and calculated output data of hydraulic percussion mining machines is the erroneous feed of manipulation signals by the control units. For the maximal fitting of the calculated and actual figures, the continuous method of control action using the third time derivative of the law of motion of the main function element is accepted, namely, the accuracy. The mathematical models of control using displacement, velocity and acceleration are developed. The service factors of mining machines are found. Based on the theory of control and the mathematical logic theory, the logical circuits of formation of manipulation signals in each phase of the working cycle are developed. The main elements are converters, integrators and accumulators ensuring decomposition of elements of the logical circuits and further generation of appropriate control action. It is found that the simplest way is to generate the control action for acceleration of the key function element. For the developed circuits, it is recommended to use general charts of the control action change, implementable for a certain design of hydraulic percussion cutting heads in certain operating conditions.

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Bubic, F. R. "FUNDAMENTAL BIOROBOTICS OF INHERENTLY LIFELIKE MACHINES." Transactions of the Canadian Society for Mechanical Engineering 23, no. 1A (March 1999): 1–18. http://dx.doi.org/10.1139/tcsme-1999-0001.

Повний текст джерела

Анотація:

An original way to define, analyze and design mechanical systems with inherently lifelike dynamic properties is presented. The construction of elementary actuating mechanisms for robotic manipulators which embody a complete set of technologically relevant biological principles is outlined. The ultimate objective is to develop a new class of mobile, autonomous, and interactive machines which dynamically emulates live musculoskeletal systems. This study introduces the mathematical models and algorithms to transform and synthesize the results of research in musculoskeletal physiology into explicit engineering design specifications. The application of a new contractile muscle-like viscoelastic motor as a servomechanical drive for articulated rigid link mechanisms is investigated. Key features of the neuromuscular force control by twitch summation are combined to formulate a pulse stream control method suitable for fluid powered mechanisms.

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Yusubov, Nizami, and Heyran Abbasova. "Full-factor matrix model of accuracy of dimensions performed on multi-purpose CNC machines." Metal Working and Material Science 23, no. 4 (December 13, 2021): 6–20. http://dx.doi.org/10.17212/1994-6309-2021-23.4-6-20.

Повний текст джерела

Анотація:

Introduction. One of the main reasons that modern multi-purpose CNC machines do not use the capabilities of multi-tool processing is the lack of recommendations for design in this direction and, accordingly, for adjustment schemes. The study of the possibilities of multi-tool processing on multi-purpose machines is the subject of the work. The purpose of research: The problem of developing full-factor matrix models of dimensional accuracy and its sensitivity to the machining process is considered to increase the machining efficiency while ensuring machining accuracy using the technological capabilities of multi-tool machining on modern multi-purpose CNC machines. For this purpose, full-factor matrix models of the size scattering fields performed on multi-tool double-carriage adjustments have been developed, taking into account the cases of processing parts with dimensions that differ sharply in different directions, which are often encountered in practice, and in this case, the significant influence of the turns of the workpiece on the processing error, especially in directions with sharply different overall dimensions. Results of research: The developed accuracy models make it possible to calculate not only plane-parallel displacements of the technological system for double-carriage adjustments, but also angular displacements around base points, take into account the combined effect of many factors – a complex characteristic of the subsystems of the technological system (plane-parallel matrix of compliance and angular matrix of compliance), the geometry of the cutting tool , the amount of bluntness of the tool, cutting conditions, etc. As a result, based on the developed accuracy models, it is possible to obtain several ways to control multi-tool machining, including improving the structure of multi-tool adjustments, calculating the limiting values of cutting conditions. Based on the developed full-factor matrix models, it became possible to develop recommendations for the design of adjustments and the creation of an automated design system for multi-tool machining for a group of modern multi-purpose CNC lathes. Scope of the results: The results obtained can be used to create mathematical support for the design of operations in CAD-systems provided for multi-tool multi-carriage machining performed on multi-purpose machines. Conclusions: The developed models and methodology for simulating the machining accuracy make it possible to increase the accuracy and efficiency of simultaneous machining, to predict the machining accuracy within the specified conditions.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Xu, Chen, Yujie Zhu, Danqing Song, Xiaogang Guo, Xiaoli Liu, Enzhi Wang, and Runhu Lu. "Comparison of DEM Models with Different Elemental Dimensions for TBM Disc Cutter Rock Fragmentation." Sustainability 14, no. 19 (October 10, 2022): 12909. http://dx.doi.org/10.3390/su141912909.

Повний текст джерела

Анотація:

Disc cutters are the dominant tool used in the excavation of hard rock formations in any underground construction application, such as when tunneling using tunnel-boring machines (TBM), as well as in shaft- and raise boring operations. Optimization of the cutting geometry of a given disc cutter for application in a rock formation often involves full-scale cutting tests, which is a difficult and costly proposition. An alternative to full-scale testing is the numerical simulation of TBM disc cutters for optimization under different settings. Recent efforts in the field of numerical simulations of rock cutting have shown the relative success of discrete element models, such as particle flow code (PFC), to simulate two- and three-dimensional rock fragmentation. This study is focused on a sensitivity analysis of PFC simulation of rock-cutting relative to the size of the elements. The calculated cutting forces were compared with the recorded forces under various conditions during full-scale tests using a linear cutting machine (LCM) on Colorado red granite (CRG). The estimated cutting coefficient and specific energy in the LCM tests and simulations showed good correlations, which validates the numerical simulation results. Two- and three-dimensional models showed that two-dimensional numerical models can offer a qualitative assessment of crack development, whereas three-dimensional models could be used to estimate the specific energy when cutting. The results can help in predicting the cutting forces in different rocks and ultimately improving disc-cutter geometry and cutter-head design.

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Rudikov, D. A., and A. S. Ilinykh. "Error analysis of the cutting machine step adjustable drive." Journal of Physics: Conference Series 2131, no. 2 (December 1, 2021): 022046. http://dx.doi.org/10.1088/1742-6596/2131/2/022046.

Повний текст джерела

Анотація:

Abstract The implementation precision of a number of adjustment bodies of a metal-cutting machine is also the most important indicator of its quality, a strictly standardized industry standard, technical conditions for manufacturing and acceptance. Moreover, the standard for limiting the error is set depending on the used denominator of the series. An essential feature of the precision of the series being implemented is that it is determined not by an error in parts’ manufacturing, but by the disadvantages of the used method of kinematic calculation. The established modes largely determine the efficiency of processing on metal-cutting machines. If the setting is set to an underestimated mode, then the performance is reduced accordingly. In the case of the mode overestimation, this leads to a decrease in durability and losses due to increased regrinding and tool changes. Creation of a complex of mathematical models for the design kinematic calculation of the metal-cutting machines’ main movement drive, which allows reducing the error in the implementation of a series of preferred numbers and increasing machining precision. The article provides a mathematical complex for analyzing the total error components, which allows determining and evaluating the total error of the drive of a metal-cutting machine by analyzing its constituent values with high precision: errors of a permanent part, errors of a multiplier part, rounding errors of standard numbers, errors in the electric motor and belt transmission. The presented complex helps to identify the role of the rounding error of preferred numbers in the total relative error formation and makes it possible to reduce it, which allows solving the problem of increasing the step adjustable drive precision. When using a mathematical complex, a fundamentally new opportunity for creating a scientific base appears, developing algorithms and programs for engineering calculation of tables that facilitate the selection of the numbers of teeth for multiple groups, structures and guaranteeing high precision of the implemented series.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Ismailova, Nelli, Valentyn Bogach, Borys Lebedev, Nataliia Oliinyk, and Serhii Manakov. "Modeling mated surfaces with the required parameters." Eastern-European Journal of Enterprise Technologies 2, no. 1 (110) (April 20, 2021): 21–26. http://dx.doi.org/10.15587/1729-4061.2021.227691.

Повний текст джерела

Анотація:

This paper has proposed improving the methods of circular and screw conversion, to be used in the design of cutting tools and toothing that include complex mated surfaces. Underlying the improvement of both methods is the construction of a mathematical base and the development of a computer subprogram, based on it, in the MATLAB system. During the research, the original screw-type curved surface and the curvilinear generatrix axis were formed on the basis of improved methods, taking into consideration the exclusion of interference at the design stage. A comprehensive solution to this problem is important for the manufacture of products by rolling. Given this, the original instrumental surface of the cutting tool takes into consideration the pairing condition between the article’s and tool’s points. The result, when designing gears and cutting tools using the proposed improved methods, assigns the curvilinear surface parametrically, represented by two-dimensional arrays characterizing its coordinates. To avoid interference at the design stage, it is necessary to analyze the intersection of the axis of the curvilinear generatrix with horizontal planes. That would make it possible, when machining an article, to avoid cutting, jamming, as well as the dangerous concentration of stresses. The accuracy and reliability of a wide range of articles in machines and machinery and other kinematic pairs also improve. The proposed improvement of circular and screw conversion methods to simulate curvilinear mated surfaces that exclude interference at the design stage is of practical interest in machine building

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Denisenko, A. F., and L. Yu Girth. "CONSTRUCTION OF A REGRESSION MODEL OF THERMAL RESISTANCE OF A CONTACT PSEUDO MEDIUM." Izvestiya of Samara Scientific Center of the Russian Academy of Sciences 23, no. 3 (2021): 47–54. http://dx.doi.org/10.37313/1990-5378-2021-23-3-47-54.

Повний текст джерела

Анотація:

The operating experience of metal-cutting machines made it possible to develop reasonable recommendations for the permissible limit values of temperature for the main subsystems of the machine, which determine the accuracy of processing. However, the decrease in the seriality of the manufactured metal-cutting equipment and the constant improvement of its designs require the development of models that are the basis of engineering techniques that allow at the design stage to predict the thermal picture of the main machine units that affect the processing accuracy. In connection with a significant number of factors influencing the formation of contact thermal resistance, and the difference in the weight of their action, it is proposed to use a pseudolayer (pseudo-medium), consisting of areas of actual contact and cavities filled with air or oil, for their comprehensive consideration in the thermal model of joining parts. To determine the significant factors that dominate the contact thermal resistance, a number of one-factor experiments were carried out. To develop a regression model of temperature change in the contact zone, a PFE of type 24 was performed. The results obtained were verified by the Cochran, Student and Fisher criteria.

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Макатьора, Д. А., А. В. Макатьора, and М. А. Зенкін. "MATHEMATICAL STUDY OF THE INFLUENCE OF KNIFE GEOMETRY WITH ARC-LIKE CROSS-SECTIONAL SHAPE ON THE PROCESS OF LONGITUDINAL FELT CUTTING." Bulletin of Sumy National Agrarian University. The series: Mechanization and Automation of Production Processes, no. 1(47) (June 20, 2022): 20–29. http://dx.doi.org/10.32845/msnau.2022.1.4.

Повний текст джерела

Анотація:

A promising study is the design and improvement of machines for longitudinal cutting of materials with minimal energy costs to perform the technological process of cutting due to the geometry of the cutting tool. The article considers the issues of reducing energy costs for the process of longitudinal cutting when using a knife blade with an arcuate cross-section. The analysis is carried out, the effective method of the analysis of influence of size of a backlash between generators of transporting rollers and size of distance from a vertical axis of rotation of transporting rollers to an edge of a knife blade with an arc-shaped cross section on the total size to determine the necessary settings in the machine of longitudinal cutting for felt, as well as to verify the reliability of analytical and experimental models of the process of longitudinal cutting with a knife with an arcuate cross-sectional shape. To determine the total amount of losses during longitudinal cutting of the material and the number of losses due to friction of the material on the face of a fixed knife with an arcuate crosssectional shape, as well as linear cutting force, a two-factor experiment was conducted for the study model. The obtained regression equations describe the total amount of losses during longitudinal cutting of the material and the number of losses due to friction of the material on the face of a stationary knife with an arcuate cross-section, suggest the adequacy of analytical and experimental models made earlier. Also make the necessary adjustments, namely, to adjust the degree of compression of the material and set the edge of the knife blade relative to the vertical axis of the transport rollers to reduce friction losses on the edge of the knife, which in turn reduces energy costs for longitudinal cutting. Comparing the total values of losses in the longitudinal cutting of the material of a knife with one-sided sharpening and a knife with an arcuate cross-section, allows you to talk about the feasibility of using a knife with an arcuate cross-section, which will reduce energy costs for the process.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Krauze, Krzysztof, Kamil Mucha, Tomasz Wydro, and Ryszard Klempka. "Assessment of the Structure of Cutting Heads with Regard to the Mining Machine Load Using Proprietary Software." Energies 15, no. 19 (September 20, 2022): 6886. http://dx.doi.org/10.3390/en15196886.

Повний текст джерела

Анотація:

The cutting heads currently used in longwall shearers, roadheaders, road milling machines and excavators are equipped with cutting tools called picks. The most commonly applied are conical picks, less frequently—radial picks or tangent picks. The picks are detachably mounted in holders installed on the body of the cutting head, to which they are usually welded (shearers) or, less frequently, form-connected (road milling machines). The arrangement of picks and holders (positioning) on the body of the cutting head, according to a previously designed diagram (pick arrangement), enables extraction of the mineral with a specific width (web) and diameter (height). Ideally, the pick arrangement should generate the lowest cutting resistance, which loads the cutting machine. The pick arrangement is characterized by design parameters (number of holders, pitch in the line and between the cutting lines) and kinematic parameters (rotational speed and advance speed). The values of these parameters result mainly from the properties of the mineral and the type of mining machine. Therefore, the correct positioning of the holders on the cutting head and their setting (cutting angles) are vitally important. This applies to both the design and implementation stages. For this purpose, the authors first developed models of pick arrangements and, next, the algorithm and software enabling the determination of cutting resistance, both in terms of the average value and its variation. Then, based on the performed calculations and the obtained results, it can be assessed whether the cutting head and the pick arrangement are properly designed. As a result of the performed calculations and analysis of the test results, the average values of the cutting resistance moment and the cutting machine advance forces were determined. It was found that the proposed pick arrangements are characterized by similar values of moments and forces. The greatest differences were found in the variability of these parameters, which translates into the dynamics of the cutting machine operation.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Niemimäki, Ossi, and Stefan Kurz. "Quasi 3D modelling and simulation of axial flux machines." COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering 33, no. 4 (July 1, 2014): 1220–32. http://dx.doi.org/10.1108/compel-11-2012-0352.

Повний текст джерела

Анотація:

Purpose – The purpose of this paper is to investigate the theoretical foundation of the so-called quasi 3D modelling method of axial flux machines, and the means for the simulation of the resulting models. Design/methodology/approach – Starting from the first principles, a 3D magnetostatic problem is geometrically decomposed into a coupled system of 2D problems. Genuine 2D problems are derived by decoupling the system. The construction of the 2D simulation models is discussed, and their applicability is evaluated by comparing a finite element implementation to an existing industry-used model. Findings – The quasi 3D method relies on the assumption of vanishing radial magnetic flux. The validity of this assumption is reflected in a residual gained from the 3D coupled system. Moreover, under a modification of the metric of the 2D models, an axial flux machine can be presented as a family of radial flux machines. Research limitations/implications – The evaluation and interpretation of the residual has not been carried out. Furthermore, the inclusion of eddy currents has not been detailed in the present study. Originality/value – A summary of existing modelling and simulation methods of axial flux machines is provided. As a novel result, proper mathematical context for the quasi 3D method is given and the underlying assumptions are laid out. The implementation of the 2D models is approached from a general angle, strengthening the foundation for future research.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Cheluszka, Piotr, Eryk Remiorz, and Jamal Rostami. "The Use of a Roadheader Simulator in Research of Dynamics and Energy-Consumption of Excavating Underground Roadways and Tunnels." Energies 15, no. 18 (September 13, 2022): 6673. http://dx.doi.org/10.3390/en15186673.

Повний текст джерела

Анотація:

Boom-type roadheaders are commonly used for excavation of roadways in underground mines, tunnels, and other architectural structures using trenchless techniques, as well as sinking shafts and occasionally excavating the harder soil and softer formations in cut and cover construction. The main research and development of these machines is to offer solutions for automatic control. This refers to automation or robotization of the operation, and raises the possibility of their eventual unmanned operation. This article presents a roadheader research simulator which implements experimentally verified mathematical models describing the dynamics of a roadheader in operation and the rock cutting process. Due to very high computational requirements, a distributed system comprising several workstations connected via TCP/IP was used. Both the visualization of the roadheader in the heading face of the excavation and the graphic simulation of the course of the rock-cutting process were carried out using the Autodesk Inventor Professional 2022 graphics engine. It provided the simulator with a virtual scene environment and enabled the control of the roadheader model’s movement during the simulated cutting process, including the generation of breakout graphics in the heading face while drilling a roadway or tunnel. The presented roadheader simulator enables the determination of various time characteristics, for example, dynamic loads, power demand, efficiency, energy consumption, and others. It is still under development.

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Zhao, Hanxin, and Kornel F. Ehmann. "Topology of Spade Drills for Wood Drilling Operations, Part 1: Spade Drill Point Geometry Definition." Journal of Manufacturing Science and Engineering 127, no. 2 (April 25, 2005): 298–309. http://dx.doi.org/10.1115/1.1794160.

Повний текст джерела

Анотація:

Spade bits, widely and routinely used in the construction industry, have not received any attention in the technical literature, yet there is a pressing need to improve the performance of these bits whose basic design has not changed for decades. To facilitate such improvements, a thorough understanding of the geometric, manufacturing, and cutting mechanics aspects of these tools is necessary. In this two-part paper, the point geometry and manufacturing issues will be discussed. To fundamentally understand the spade drill bit’s behavior, a complete mathematical model of its principal topological elements will be established. In conjunction with this model, the corresponding analytical formulations of the geometry and kinematics of the appropriate manufacturing procedures will also be formulated. In unison, these models will lay the foundation for a methodology and a software package for a detailed geometric analysis of all relevant cutting angle distributions and edge profiles of the spade bit. This will facilitate, at a later point, new point developments rooted in rigorous analytical models.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Tyapin, Aleksey, Vasiliy Panteleev, and Evgeny Kinev. "Mathematical models of non-sinusoidal power supply of a three-phase transverse field MHD inductor." E3S Web of Conferences 270 (2021): 01024. http://dx.doi.org/10.1051/e3sconf/202127001024.

Повний текст джерела

Анотація:

The article presents an approach to the development of mathematical models of non-sinusoidal and dual-frequency power supply for a linear induction MHD machine for metallurgical purposes. The issues of construction and numerical modeling of the modes of a three-phase inductor for a liquid aluminum stirrer are considered. Reduction of losses is ensured by the use of a toothless design of the MHD inductor. The absence of steel teeth reduces saturation of the magnetic circuit and current distortion. It is proposed to use the parametric model of the inductor under the furnace in the ANSYS environment to clarify the modes of the complex. To take into account mutual induction, using controlled sources, a circuit model was built, and a numerical calculation of the modes was carried out. The characteristics of instantaneous currents and voltages are obtained when powered from a three-phase source with close frequencies, with pronounced beats. It is shown that the presence of mutual inductance redistributes currents in the delta windings, which must be taken into account when developing the design of linear induction machines. It is proposed to use sources with non-sinusoidal periodic currents in the modeling system. The analysis is carried out and the main types of modulated voltage characteristics in the power supply system of the induction MHD stirrer are shown.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

ALDOSHIN, NIKOLAY V. "DESIGNING A HYBRID WORKING UNIT FOR INTRODUCING FALLOW LANDS INTO CROP ROTATION." Agricultural engineering, no. 2 (2022): 8–12. http://dx.doi.org/10.26897/2687-1149-2022-2-8-12.

Повний текст джерела

Анотація:

Constantly increasing requirements to reduce the energy efficiency of technological processes in crop production call for designing new mechanization means capable of cutting and performing surface tillage in one pass of a unit. The study of modern scientific and patent literature has revealed that the existing individual models of such machines are not used in agricultural production. The work aims to theoretically justify a new hybrid unit designed for simultaneous cutting and soil rotatilling based on the system approach. Theoretical studies showed that the initial requirements for removing low-value and weedy vegetation with simultaneous soil surface rotatilling. The authors considered a model of combining these technological processes, taking into account the requirements for fodder harvesting technology. A provision was made that during soil preparation it is necessary to undercut the vegetation completely with the least energy inputs without reducing its quality for further impacts. In mathematical designing of the working unit, rheological properties of cultivation objects – soil layer and vegetative material – were taken into account. Based on these research outcomes, the authors developed the effective design of a working unit combining cutting with soil rotatilling. Comparative analyses of the agro-energy intensity of the combined operation showed a reduction of specific energy consumption by 10…12% on average.

Стилі APA, Harvard, Vancouver, ISO та ін.

19

ALDOSHIN, NIKOLAY V. "DESIGNING A HYBRID WORKING UNIT FOR INTRODUCING FALLOW LANDS INTO CROP ROTATION." Agricultural engineering, no. 2 (2022): 8–12. http://dx.doi.org/10.26897/2687-1149-2022-2-8-12.

Повний текст джерела

Анотація:

Constantly increasing requirements to reduce the energy efficiency of technological processes in crop production call for designing new mechanization means capable of cutting and performing surface tillage in one pass of a unit. The study of modern scientific and patent literature has revealed that the existing individual models of such machines are not used in agricultural production. The work aims to theoretically justify a new hybrid unit designed for simultaneous cutting and soil rotatilling based on the system approach. Theoretical studies showed that the initial requirements for removing low-value and weedy vegetation with simultaneous soil surface rotatilling. The authors considered a model of combining these technological processes, taking into account the requirements for fodder harvesting technology. A provision was made that during soil preparation it is necessary to undercut the vegetation completely with the least energy inputs without reducing its quality for further impacts. In mathematical designing of the working unit, rheological properties of cultivation objects – soil layer and vegetative material – were taken into account. Based on these research outcomes, the authors developed the effective design of a working unit combining cutting with soil rotatilling. Comparative analyses of the agro-energy intensity of the combined operation showed a reduction of specific energy consumption by 10…12% on average.

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Grischenko, Volodimir Mikolayovich, and Kateryna Serhiivna Leonova. "Application of computer systems for modeling dynamic processes of lifting machines." Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines, no. 2 (December 31, 2021): 69–77. http://dx.doi.org/10.20998/2078-9130.2021.2.249498.

Повний текст джерела

Анотація:

The main task of mechanical engineering is to organize the production of a range of machines to meet the needs of all industries. These are power, transport, lifting and transport units, agricultural machinery, construction industry, etc. Among them, one can single out devices in which the relative movement of their parts is assigned, that is, kinematic pairs are included in the calculation models. The real operating conditions of machines are varied, but most often they are associated with periodic starts-stops, which determines the relevance of the study of unsteady modes. The analysis of the operation of such models becomes more complicated. For successful design results, mathematical modeling of individual processes in mechanisms is carried out. One of the first calculations is dynamic. Modern, available CAD / CAE systems for modeling and analysis provide automation capabilities, building more realistic design models. The paper discusses the approbation of the use of CAD for modeling the dynamics of a jib crane with a set of four units: platform, boom, sleeve and rod. The developed model is combined: the platform and the sleeve correspond to the kinetostatic model, and the boom and rod are elastic. The crane is designed to perform lifting operations in a vertical plane, with the possibility of relative movement in 3 rotational and one translational kinematic pairs. The performed calculations of the static, modal and dynamic analyzes of the links of the mechanism confirm the adequacy of their models. Among them is the task of instantaneous load application, which is typical for the "lifting and picking" operating mode of crane lifting mechanisms. The deformation of the entire structure in one of the boom positions is also considered. The determination of the reaction forces in the hydraulic cylinder provides important information for the selection of the power unit.

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Doreth, Karl, Jan Henjes, and Stefan Kroening. "Approach to Forecast Energy Consumption of Machine Tools within the Design Phase." Advanced Materials Research 769 (September 2013): 278–84. http://dx.doi.org/10.4028/www.scientific.net/amr.769.278.

Повний текст джерела

Анотація:

For environmental and economic reasons, energy- and resource- efficient operations of cutting machines are increasingly important. The determination of properties and functions of machine tools, which affect future energy consumption in operation, essentially takes place within the design phase by combining required components. Therefore, it is necessary to develop approaches to find an efficient optimum between energy consumption, productivity, acquisition costs and operating costs within the design phase of a machine tool. However, the energy consumption of a machine tool depends on the application scenario. In addition to that, it is difficult to forecast the energy consumption of several components because of their mutual interaction. Existing approaches to forecast the energy consumption of a machine tool within design phase are based on complex simulation or mathematical models which are difficult to parameterize for the design of a machine tool and thus, for the comparison of various configuration alternatives. An alternative for forecasting energy consumption is the use of empirical information. That information can be acquired by measuring the energy consumption of machine tools in operating production systems. This paper presents an approach to forecast the energy consumption of machine tools within the design phase, which will be developed by the Institute of Production Engineering and Machine Tools. It will be based on the data feedback (empirical information) from a machine tool operating in an existing manufacturing system. For this purpose, a logger module will be developed, which continually captures the energy consumption by means of the machine integrated sensors. That information will be sent back to an energy navigator module, which processes that information in order to forecast the energy consumption of a new designed machine tool. Also, the lifecycle costs will be calculated in order to rate cost and benefits of each machines lifecycle in terms of energy consumption.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Eser, Aykut, Elmas Aşkar Ayyıldız, Mustafa Ayyıldız, and Fuat Kara. "Artificial Intelligence-Based Surface Roughness Estimation Modelling for Milling of AA6061 Alloy." Advances in Materials Science and Engineering 2021 (February 12, 2021): 1–10. http://dx.doi.org/10.1155/2021/5576600.

Повний текст джерела

Анотація:

This study introduces the improvement of mathematical and predictive models of surface roughness parameter (Ra) in milling AA6061 alloy using carbide cutting tools coated with CVD-TiCN in dry condition. An experimental model has been improved for estimating the surface roughness using artificial neural networks (ANN) and response surface methodology (RSM). For these models, cutting speed, depth of cut, and feed rate were evaluated as input parameters for experimental design. For the ANN modelling, the standard backpropagation algorithm was established to be the optimum selection for training the model. In the forming of the network construction, five different learning algorithms were used: the conjugate gradient backpropagation, Levenberg–Marquardt, scaled conjugate gradient, quasi-Newton backpropagation, and resilient backpropagation. The best consequent with single hidden layers for the surface roughness was obtained by 3-8-1 network structures. The statistical analysis was performed with RSM-based second-order mathematics model. The influences of the cutting parameters on surface roughness were defined by using analysis of variance (ANOVA). The ANOVA results show that the depth of cut is the most effective parameter on surface roughness. Prediction models developed using ANN and RSM were compared in terms of prediction accuracy R2, MEP, and RMSE. The data estimated from ANN and RSM were realized to be very close to the data acquired from experimental studies. The value R2 of RSM model was higher than the values of the ANN model which demonstrated the stability and sturdiness of the RSM method.

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Dai, Peng, Song Han, Xuxu Yang, Hui Fu, Yanjun Wang, and Jianjun Liu. "Analysis of the Factors Affecting the Construction of Subway Stations in Residential Areas." Sustainability 14, no. 20 (October 12, 2022): 13075. http://dx.doi.org/10.3390/su142013075.

Повний текст джерела

Анотація:

To design a more suitable scheme under different conditions so that subway stations can play their role better, this study investigated the construction elements of subway stations in residential areas. Metro stations in residential areas are generally located at the intersection of urban roads. As the “handover space” of the city, the construction principle should be based on people’s experience. As the core basis for traffic planning and future operation management, construction of subways in residential areas should take into consideration factors such as trip volume, distribution, and mode selection of residents, and be determined based on such mathematical models as the unit factor method, gravity model, and disaggregated analysis method. Station site selection is based on the point, line, and surface elements, and the importance of a station in the line network is judged by degree and betweenness centrality; the accessibility of the line network is determined by connectivity. In this study, the influencing factors of residential area subway station construction are divided into construction elements and site selection. Internal construction elements of stations include station entrances and exits, escalators, ticket machines, and transfer routes, and the conclusion of the mathematical model is used to select or give opinions about the internal construction elements of the subway. The point, line, and surface elements and the connection relationship between the subway and buses are used to determine the site selection of the subway. Furthermore, this paper discusses the three elements that affect the construction of the subway, comprehensively considers the functional requirements of the subway, and makes reasonable adjustments to each element. Finally, the requirements for the elements of the subway construction are determined.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Kriachok, Oleksandr, and Dmytro Sushko. "SIMULATION OF ELECTROMAGNETIC PROCESSES IN THE WORKING AREA OF SPECIAL DEVICES CONSIDERING THE INFLUENCE OF THE MAGNETIC SCREEN." Bulletin of the National Technical University «KhPI» Series: New solutions in modern technologies, no. 3(13) (October 26, 2022): 18–23. http://dx.doi.org/10.20998/2413-4295.2022.03.03.

Повний текст джерела

Анотація:

The work is devoted to the creation of a modern web-oriented software platform for designing magnetic systems of special devices and electric machines of new generations that are built on the basis of permanent magnets. To solve the problem of increasing the accuracy of the performed calculations it is necessary to develop new mathematical models that take into account the shielding effect of structural elements on physical processes in electromechanical devices. To obtain mathematical expressions for the calculation of strength components of the magnetic field at given points of piecewise homogeneous space, the method of secondary sources is applied. The studied system is of a generalized design of a magnetic suspension built on the basis of the connected permanent magnets that are facing each other. The entire structure is placed in the shielded housing. Since the electromagnetic system of the device contains parts of a complex shape in its design and has non-linear characteristics of the environment, in order to obtain a mathematical model, an approach is suggested that is based on that a task of calculating the magnetic field for a piecewise homogeneous medium can be formulated in the form systems of Fredholm linear integral equations of the second kind. In accordance with the method of secondary sources, the solution to the field calculation problem is divided into two stages: first the distribution of additional sources is found, the effect of which is equivalent to the influence of a heterogeneous environment on physical processes in work zone, and, at the next stage, based on the principle of superposition of fields, the total magnetic field caused by the presence of primary and secondary sources is calculated. Based on the obtained mathematical model, a calculation algorithm was developed and a web-oriented software system for modeling magnetic field characteristics was created. Using the developed software application, numerical experiments were conducted to simulate the magnetic field in the work zone of an electrical device according to the given electrophysical and geometric design parameters. The proposed approach can be used to solve other similar problems when it is necessary to calculate the characteristics of a system containing permanent magnets in the conditions of a piecewise homogeneous environment.

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Ignatyuk, Roman, Oleksandr Ryzhyi, Leonid Serilko, Oleksandr Stadnyk, and Dmytro Serilko. "JUSTIFICATION OF TRANSPORT PARAMETERS AND MODELING OF THE PROCESS OF DESTRUCTION OF THE ELASTIC-PLASTIC ENVIRONMENT." Transactions of Kremenchuk Mykhailo Ostrohradskyi National University, no. 5(130) (October 27, 2021): 89–96. http://dx.doi.org/10.30929/1995-0519.2021.5.89-96.

Повний текст джерела

Анотація:

Purpose. The substantiation of the mathematical model of mechanical deformation of the elastic-plastic medium and the modeling of the transport process of the expansion assemblies. Methodology. Mathematical and theoretical studies were based on the fundamental theory of continuum mechanics and general positions of engineering mechanics. Analytical and graphical analysis of mathematical models carried out on a PC in a specialized software complex. Results. In the current conditions of economic development of the country, considerable attention should be paid to the development and modernization of certain sectors of the economy. Significant amounts of work, which are accompanied by the development of soil of different properties, which can be defined as an elastic-plastic material. These studies will solve a number of problems that are acute not only in agriculture but also in construction, in the open pit mining, reclamation, one of which is an imperfect process of loosening the soil during its cultivation. Therefore, the urgent problem is to establish rational parameters of the transport surface of the unit for loosening the elastic-plastic material. The developed mathematical model allows determining the emerging stress, which in turn determines the boundary of the destruction of the elastic-plastic material. In the design of lining assemblies, it is advisable to have a radius of the outlet section R = 0.18 m or more. Originality. The mathematical models for the process of destruction of elastic-plastic material and forecasting of optimal transport parameters for designing of expansion assemblies are obtained. Practical value. The developed mathematical model will provide an improvement in the process of loosening elastic-plastic material, and engineering calculations during the design of the rutter can prevent unwarranted increase in resistance, with displaced materials on the cutting surface. References 10, figures 8.

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Kondrashov, Serhii, Ihor Hryhorenko, and Aleksandr Opryshkin. "DEVELOPMENT OF A SITUATION SYSTEM WITH FUZZY LOGIC FOR THE SECOND LEVEL OF THE INFORMATION AND MEASUREMENT SYSTEM." Bulletin of the National Technical University «KhPI» Series: New solutions in modern technologies, no. 4(14) (December 28, 2022): 24–34. http://dx.doi.org/10.20998/2413-4295.2022.04.04.

Повний текст джерела

Анотація:

Nowadays, in production and in everyday life, there is a question of improving the quality and efficiency of grinding systems. These can be both cement and grain factories, as well as coffee shops that use machines for grinding coffee. Effective management of the grinding process is of great importance for increasing the productivity and quality of the final product. Management of the grinding process is a complex task because many factors affect the process. In addition to the factors, the degree of wear of the cutting surfaces, the backlash in mechanical transmissions, which increases the distance between the grinders, and the material from which they are made, must also be taken into account during the analysis. Mathematical models describing the grinding process cannot be completely perfect, because they contain a limited number of factors that affect the process and all of them are defined in different physical quantities. Also, when developing a mathematical model, it is practically impossible to take into account dynamic changes in the object of control, which can be both linear and non-linear. All these features of a complex object of control make it necessary to move to the creation of a situational system with fuzzy logic, which will provide an opportunity to take into account all the features and complexities that arise when creating an «image» of the object of control. For the development of a situational system with fuzzy logic, the method of constructing a fuzzy conclusion of the Mamdani situational type, most suitable for the tasks of metrological support, was chosen. With the help of a graphical user interface, it was possible to build the situational system with fuzzy logic, which made it possible to establish the second level of the information and measurement system, where the technological and metrological «image» of the control object is formed, taking into account the influence of external and internal factors, the necessary technological regimes that will positively affect the uniformity of grinding.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Gašparík, Jozef, Vít Motyčka, Patrik Šťastný, and Sylvia Szalayová. "Multi-Criteria Optimization of Mechanized Earth Processes and Its Impact on Economic and Environmental Sustainability." Sustainability 14, no. 1 (December 22, 2021): 78. http://dx.doi.org/10.3390/su14010078.

Повний текст джерела

Анотація:

The optimization of mechanized construction processes has a very important impact on economic and environmental sustainability. Our analyses evaluate key factors that affect the quality, environment, and economics of mechanized earth processes. This paper also presents approaches in this area in Slovakia and abroad, and existing mathematical models for the optimal design of earthmoving machinery. The main goals of our paper are the proposal of a method of machine selection for excavation including a multi-criteria optimization method with software support and application and verification of this method in a model example. A total of nine scientific methods applied in our paper are analyzed. The key results of the research work in terms of the set goals are given in the Conclusion, where the key research results are summarized. The results of the research work presented in the paper have a direct impact on economic and environmental sustainability, which can be achieved already in the phase of construction preparation. Applications of information technologies in multi-criteria optimization of the selection of construction machines for earth processes enables their use in the BIM (building information modeling) model.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Burdeina, Vyktoryia, Hanna Hrinchenko, Svitlana Artiukh, and Andrii Trishch. "ESTIMATION OF ACCURACY OF COORDINATED SMALL DIAMETER HOLES WITH CUTTING TOOL DIRECTION." Bulletin of the National Technical University «KhPI» Series: New solutions in modern technologies, no. 2(8) (June 15, 2021): 9–14. http://dx.doi.org/10.20998/2413-4295.2021.02.02.

Повний текст джерела

Анотація:

The dimensional analysis of the initial parameters of the coordinated dimensions of the holes is presented. Issues related to the assessment of the accuracy of the location of the surfaces of deep holes are considered. The influence of various technological factors on the magnitude of scattering of coordinated dimensions is studied. Experimental studies using experimental design methodology, which was used for sample preparations 45 steel, cast iron SCH15, aluminum alloys. Factors such as the cutting angle, the hardness of the workpiece, the cutting force and their effect on the diameter of the impression and its depth were studied. As a result of the experiments, a slight effect of the drilling force on the diameter and depth of the impression was found. However, it was found that the angle of the core leads to a directly proportional increase in the diameter of the imprint and inversely affects its depth. The hardness of the material has a more significant effect on the diameter of the imprint than on its depth. The total influence of controlled factors significantly affects the diameter of the imprint. Minimum core drilling angles are proposed for some materials. A mathematical model of the accuracy of machining coordinated holes is proposed on the basis of estimating the coefficients of the regression equation and finding the required mathematical models of the scattering fields of dimensions and deviations. As factors that vary during the drilling of coordinated holes, were taken: the length of the conductor sleeve, the departure of the tool, the hardness of the workpiece, the diameter of the tool. It is found that with increasing tool diameter and guide sleeve length decreases the amount of dimensional scattering from the base and positional deviations, and increasing tool departure and improving the physical and mechanical properties of the workpiece increase the size of the size scattering field from the base and positional deviation. An additional factor was introduced: the gap in the combination between the cutting tool and the conductor sleeve and obtained mathematical dependences of the influence of factors on dimensional accuracy when machining deep holes with the direction of the cutting tool. It is shown that the introduction of an additional factor - the gap, did not change the essence of the process of errors on small aggregate machines, and the change in diameters does not lead to a significant increase in scattering fields.

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Bo, Kun, Mao Sen Wang, and Zhi Qiang Zhao. "Numerical Simulation on Bottom Hole Flow Fields of Reverse Circulation Bit." Applied Mechanics and Materials 256-259 (December 2012): 2826–30. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.2826.

Повний текст джерела

Анотація:

Air reverse circulation (RC) drilling is becoming an increasingly popular technique in engineering fields. It can be used in geological exploration, water well drilling and infrastructure construction and so on. RC bit is the key accessory in this technique. Its structural parameters directly influence cutting transportation during reverse circulation drilling. In order to explain the formation mechanism of reverse circulation, established mathematical models and physics model of the RC bit and studied drilling fluids transportation under the bottom hole. Conducded numerical simulation about velocity field and pressure field of bottom hole flow field using software FLUENT with different parameters of the RC bit, including the size and position of nozzles, the angle of inner nozzle and so on. The result of simulation and experiment show that increase of the effective turbulence zone can improve efficiency of RC transportation. Inner nozzles can produce stable negative pressure region in the central channel, and ensure cutting transportation as RC methods. The data and results are helpful to optimize the structure and size of the RC bit. It can shorten the research period, decrease costs and improve the design ability.

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Cheluszka, Piotr, and Amadeus Jagieła-Zając. "Identification of a Mathematical Model for the Transformation of Images for Stereo Correspondence Measurements of Mining Equipment." Energies 15, no. 17 (August 30, 2022): 6339. http://dx.doi.org/10.3390/en15176339.

Повний текст джерела

Анотація:

The stereometry of the working units of mining machines is optimized at the design stage, in terms of selected criteria based on computer simulations of the mining process. The recovered bodies of cutting heads or drums used in manufacturing are regenerated in the overhaul process. Ensuring that their dimensions comply with the nominal ones is labor-intensive and raises production costs. However, deviations of these components from the nominal shape can make it difficult to position the pick holders (which can cause collisions) or make welding them impossible (which results from too large a distance between the pick holders’ base and the side surface of the working unit). This applies especially to robotic technologies. By utilizing automatic (online) measurements of the distribution of the actual distances of the pick holders’ bases from the side surface of the working unit (taken during their positioning using a robot), it is possible to correct their positions without changing the setting of the pick itself. This measurement can be carried out using the non-contact stereovision method. This paper presents a method of matching raster images obtained from a stereovision system installed on an experimental robotic station. The results are presented of the numerical research carried out to select a mathematical model of the geometric transformation of images, for ensuring the effectiveness of the developed method.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Minaeva, Yu V. "ATHEMATICAL MODEL FOR THE OPTIMISATION OF HIERARCHICAL MULTI-LEVEL PRODUCTION SYSTEMS." Herald of Dagestan State Technical University. Technical Sciences 45, no. 2 (December 17, 2018): 140–48. http://dx.doi.org/10.21822/2073-6185-2018-45-2-140-148.

Повний текст джерела

Анотація:

Objectives The aim of the study is to develop a mathematical model for the complex solution of various problems in designing and reconstructing the technological system of a production workshop of a machine-building enterprise.Methods Complex system theory and an aggregative decomposition approach are used as the methodological basis for modelling complex hierarchical productions, making it possible to represent a complex system in the form of a set of interconnected subsystems.Results A mathematical model designed for a complex solution of problems associated with the formation of an optimal production programme and selection ofequipment was developed. Operative parameters for processing machines according to a single optimisation criterion for the workshop were established. Distinctive features of the optimisation model proposed in the article are the possibility of its application both for design and for the reconstruction of a technological system, as well as the possibility of simple scaling to the required level (i.e. the workshop as a whole or a separate section).Conclusion The article presents a complex mathematical model for optimising the technological system based on a single optimisation criterion for the workshop, combining the solution of the main tasks of design and reconstruction of the workshop. The use of a single integral optimisation criterion for several problems allows the strong interrelationships between individual tasks to be taken into account. The model is based on the principle of arranging a model from a set of typical elements, easing the construction of models for any sub-task combinations, as well as their respective options. It is possible to use the model’s multi-level unification and scalability to increase modelling efficiency and thus optimise complex multinomenclature productions.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Gomar, Mostafa, and Behzad Elahifar. "Application of Digitalization in Real-Time Analysis of Drilling Dynamics Using Along-String Measurement (ASM) Data along Wired Pipes." Energies 15, no. 23 (November 25, 2022): 8930. http://dx.doi.org/10.3390/en15238930.

Повний текст джерела

Анотація:

An automated drilling system requires a real-time evaluation of the drilling bit during drilling to optimize operation and determine when to stop drilling and switch bits. Furthermore, in the dynamic modeling of drill strings, it is necessary to take into account the interactions between drilling bits and rock. To address this challenge, a hybrid approach that combines physics-based models with data analytics has been developed to handle downhole drilling measurements in real time. First, experimental findings were used to formulate mathematical models of cutter–rock interaction in accordance with their geometrical characteristics, rock properties, and drilling parameters. Specifically, these models represent the normal and contact forces of polycrystalline diamond compact cutters (PDCs). Experimental data are analyzed utilizing deep learning, nonlinear regression, and genetic algorithms to fit nonlinear equations to data points. Following this, the recursive least square was implemented as a data analytic method to integrate real-time drilling data, drilling bit models, and mathematical models. Drilling data captured by the along-string measurement system (ASM) is implemented to estimate cutting and normal forces, torque, and specific energy at the bit. The unique aspect of this research is our approach in developing a detailed cutter–rock interaction model that takes all design and operation parameters into account. In addition, the applicability of the algorithm is demonstrated by real-time assessments of drilling dynamics, utilizing downhole digital data, that enable the prediction of drilling events and problems related to drilling bits.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Seif, Javad, and Masoud Rabbani. "Component based life cycle costing in replacement decisions." Journal of Quality in Maintenance Engineering 20, no. 4 (October 7, 2014): 436–52. http://dx.doi.org/10.1108/jqme-08-2013-0053.

Повний текст джерела

Анотація:

Purpose – The purpose of this paper is to assess life cycle costing (LCC) of the equipment in a more realistic, precise, and applicable manner, and to apply it to a real industrial problem. Design/methodology/approach – Based on the failure rates of the components of a machine, the LCC is assessed, mathematically modeled, and incorporated to the parallel machine replacement problem with capacity expansion consideration. The problem is modeled as mixed integer programming which intends to minimize the total costs incurred during a planning horizon of several periods for the machines of the same type with different ages. The decision variables are the number of machines to be purchased/salvaged in each period. A genetic algorithm (GA) is developed for solving the problem and its efficiency is verified. Findings – In conventional models presented for calculation of LCC, corrective maintenance (CM) costs of the machines are incorporated to the model as a whole which may result in inaccurate calculations. Obtaining this value is also very difficult and it can be different for machines with different ages. By calculating the CM costs of a machine based on the failure rates of its components, the LCC can be properly estimated in a realistic and precise manner. The presented GA is also proven to be efficient for solving problems of almost any size with different number of machines, components, and planning periods. Practical implications – The presented model and GA are applied to a real case of a construction company that needs to determine a purchase/salvage schedule for its loaders in the next ten years. Results of the calculated schedule imply that employing new loaders rather than maintaining the aged ones generally results in the minimum LCC. Originality/value – This paper presents a novel approach for precise, meaningful, and practical LCC calculation. The mathematical model and its solving method can be utilized by both the manufacturers and buyers of equipment as a tool which determines a parallel machine purchase/salvage schedule for a planning horizon of several periods which incurs minimum overall cost. The presented material can be also applied to other industrial problems and cases.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Abdulmazhidov, Kh A. "Dependence of the performance of the reclaiming sewer cleaner with rigid guides from interchangeable bucket tools capabilities." Vegetable crops of Russia, no. 6 (December 10, 2022): 125–29. http://dx.doi.org/10.18619/2072-9146-2022-6-125-129.

Повний текст джерела

Анотація:

Relevance. Cleaning of reclamation channels is a very relevant event. The need to clean the canals and maintain them in working condition becomes obvious during the flood period, when it is necessary to remove excess water. The paper presents mathematical models for determining the performance of the PP-303 canal cleaner, a feature of which is the rectilinear movement of the bucket on rigid guides along the bottom along the axis of the canal to be cleaned.Methods. The article is formed on the basis of experimental research methods. The research was carried out based on experimental and calculated data. A network of drainage canals of the drainage system was taken as the research object, and the working equipment of the canal cleaner was taken as the research subject. Performance, which is the amount of products produced by the machine per unit of time, can be of three types (theoretical, technical, and operational) and can be determined with consideration of the design parameters of the working equipment. During the operation of trench cutting machines, their performance directly depends on the main parameter, namely, the depth of the canal being built; in the case of canal cleaning with canal cleaners, this parameter cannot be considered as the main one. This is due to the fact that siltation and sediments accumulating on the bottom and slopes of the canals during the operation of the reclamation system are extremely unevenly distributed along the length of the canal. The highest concentration and amount of sediments and siltation is observed mainly at the mouth of the canals, the junctions of canals of different levels, and the junctions of the drainage with the drainage canal. In this case, the most significant parameter is the thickness of the chips removed from the bottom and slopes of the canal by the bucket.Results. The results of the research showed that the performance of the channel cleaner, as a batch machine, is influenced by the very design of the working equipment, the main element of which is a bucket capable of moving in a straight line along rigid guides at different speeds. With obvious high values of the performance of continuous channel cleaning machines, it can be concluded that the channel cleaner RR-303 showed high values of technical and operational characteristics, mainly due to the use of a trapezoidal profile bucket.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

LAGUNOVA, Yuliya Andreevna, Stanislav Anatol’evich MAYOROV, and Gennadiy Alexeevich BOYARSKIH. "Statistical analysis of stress-strain state of bearing jaw crusher." NEWS of the Ural State Mining University 1, no. 2 (June 15, 2020): 159–71. http://dx.doi.org/10.21440/2307-2091-2020-2-159-171.

Повний текст джерела

Анотація:

The relevance of the work. When creating particularly large machines and systems, in the case of their 3D modeling and detailed study, the load on the central processor of the computer, as well as on the graphic and RAM modules, increases, which significantly slows down the design process and calculations. In the article, a statistical analysis of the stress-strain state of the jaw crusher bearing is carried out to establish the correspondence of the theoretical and actual structural models taking into account all workloads. The objectives of the study. Consider the task of selecting a simpler and “easier” for the calculation model programs, not difficult to parameterize, compared with the original bearing model, but providing accuracy in the calculation in an acceptable range of errors. To analyze the stress-strain state of the bearing assembly with various geometric parameters. Research methodology. In the calculations, the finite element method was used. Used specialized software package APM WinMachine. A computational experiment was conducted. A correlation analysis of the theoretical and actual structural model of the bearing is carried out. Results. Mathematical models of the metal structures of bearings of various sections are given and the locations of the highest stresses are identified. Calculation errors and correlation dependencies of stresses are established taking into account the Pearson, Fisher criteria and the construction of the Taylor series. Conclusions. The results of a computational experiment satisfy the requirements and can be used to solve further problems of designing bearing assemblies. In the future, a parameter-dependent model can be created that makes it easier to calculate using any type of bearing

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Poliakov, Andriy, Volodymyr Kryvtsun, Maksym Kalenyk, and Viacheslav Nagachevskyi. "A formalized representation of exponential models of the main indicators of reliability, the limitations of their use for the characteristics of engineering weapons." Journal of Mechanical Engineering and Transport 12, no. 2 (February 2021): 100–105. http://dx.doi.org/10.31649/2413-4503-2020-12-2-100-105.

Повний текст джерела

Анотація:

The article deals with the solution of a scientific and applied problem to study the possibility of using existing exponential models to determine the reliability indicators of engineering weapons. Exponential models are widely used to assess the reliability of objects, mainly consisting of radio electronic elements, which led to their mass distribution in the aviation industry, air defense facilities, etc. Experimental operation of typical samples of military road-building equipment and experimental studies of the operating time of the main blocks and assemblies of engineering weapons show that the rate of failure and restoration of these products are functions of time. This state of affairs is associated with the design features of engineering weapons, which are characterized by the complex use of electrical, mechanical, hydraulic and other systems, while during use these systems can often experience significant overloads. At the same time, it should be borne in mind that today the engineering weapons that are in the units generally have a service life longer than that guaranteed by the manufacturer, which significantly affects the parameters of failure rates and recovery. The article shows the procedure for obtaining expressions for calculating the main indicators of the reliability of complex technical systems with an exponential distribution of operating time to failure and their recovery time and it is allowed to use them only for minimal periods of time (from several hours to several days, depending on the intensity of the use of machines) due to for the non-ergodic nature of the process of failures and restorations. In addition, the use of these models should be accompanied by an assessment of the adequacy of the results obtained to the real process with the adjustment of the duration of the corresponding time intervals. Thus, the construction of mathematical models of the technical state of engineering equipment will be accompanied by a search for other conceptual approaches to determining the reliability indicators of engineering equipment and methods for calculating these indicators.

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Zagretdinov, I. Sh, V. V. Kucherov, Ya V. Zakharov, and I. I. Shabanov. "The Centenary of Teploelektroproekt Institute: from the Past to the Future." Safety and Reliability of Power Industry 11, no. 4 (January 21, 2019): 264–73. http://dx.doi.org/10.24223/1999-5555-2018-11-4-264-273.

Повний текст джерела

Анотація:

The article is devoted to the one-hundredth anniversary of Teploelektroproekt Institute, and presents areas of the institute’s current activities. Despite the difficult conditions, the financial and economic crisis, the Institute continues to be one of the leading design organizations in the field of developing projects of thermal power plants operating on organic fuels (coal, natural gas, fuel oil) with the installation of steam-turbine, steam-gas, gas turbine units and substations of various voltages, in terms of its production capacity, technical equipment, scope of work performed and scale of orders received. The technical policy of the Institute is orientated at the future, the key objective being ensuring a high scientific and technical level of projects, and technical and commercial proposals developed by the Institute. The Institute uses cutting edge technologies in the development of technical documentation; introduces advanced technical solutions throughout the project and conducts its uniform policy for the projects under development; provides consistently high quality of technical documentation on the basis of continuous improvement of its quality management system; improves methods of calculation/mathematical models and their implementation in the design process; ensures comprehensive and total accounting of the Customer’s requirements at preparation of technical and commercial offers, design of new and/or reconstruction and technical re-equipment of existing power-generating facilities; maintains close relations with scientific and design organizations, manufacturers of equipment, products and materials for the purpose of introduction of available advanced scientific and technical achievements in project documentation. Standardized layouts of the main buildings are designed for pulverized coal-based generating units of ultra-supercritical steam conditions, for circulating fluidized bed boilers, flue gas denitrification and desulphurization plants, for combined cycle plants. Examples of the power plant designing are presented for industrial facilities utilizing nonconventional fuels. A short description is given about the institute’s references in the field of construction of combined cycle and cogeneration plants as well as pulverized coal-based plants.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Mikova, Marina N., and Evgeniya N. Akbulyakova. "A study of clay soil deformability over time." Vestnik MGSU, no. 12 (December 2020): 1654–62. http://dx.doi.org/10.22227/1997-0935.2020.12.1654-1662.

Повний текст джерела

Анотація:

Introduction. The study is focused on the process of clay soil deformation over time, provided that this soil, featuring varied liquidity index values, is exposed to constant load. The consolidation process is slow; it can run for years or decades in clay soils. Long-term deformations of clay soils must be taken into account in the course of design and construction of buildings and structures, on the one hand, and in the process of analyzing settlement rates and maximal settlement values for foundation beds, on the other hand. Materials and methods. Semi-solid, low-plasticity, high-plasticity, very high plasticity, and free-flowing clay samples were used in the study. The parameters under research encompass relative and absolute deformation of soil samples over time. These parameters are dependent on the soil liquidity index value. All laboratory tests were carried out in compression machines, and tested samples were exposed to constant load. The experimental data thus obtained were supplemented by the information provided M.A. Koltunov. Results. Values of absolute deformations and time-to-relative deformation ratios were obtained for clays having different liquidity index values. The analysis of the time-to-relative deformation curves shows that deformations develop over time at different rates depending on the liquidity index of clay soils. An increase in the value of the liquidity index boosts the values of initial deformations and deformation rates. Conclusions. The equations, derived in the course of the study, allow to analyze the deformation of semi-solid, low-plasticity, high-plasticity, very high plasticity, and free-flowing clays for various time ranges depending on the initial clay liquidity index. The accuracy of the approximation of these equations varies from 0.801 to 0.993, which makes it possible to characterize these dependences as high quality mathematical models.

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Дворжак, В. М. "ЗАСТОСУВАННЯ МЕХАНІЗМУ ЧЕТВЕРТОГО КЛАСУ ДЛЯ ПРИВОДУ ВУШКОВИХ ГОЛОК ОСНОВОВ’ЯЗАЛЬНОЇ МАШИНИ". Bulletin of the Kyiv National University of Technologies and Design. Technical Science Series 146, № 3 (11 січня 2021): 15–24. http://dx.doi.org/10.30857/1813-6796.2020.3.1.

Повний текст джерела

Анотація:

Development and research of functionally-adequate target mechanisms of technological machines of light industry with application of applied CAE-programs. Used the apparatus of vector algebra; analytical and numerical methods for determining the position functions of planar mechanisms containing a structural group of the fourth class of the second order, based on the vector transformation of coordinates; random search method for metric synthesis of flat mechanisms; methods of computer visualization and animation of kinematic schemes of flat mechanisms of higher classes. Mathematical models describing the position functions of the mechanism of eyelets of a warp knitting machine containing a structural group of the fourth class of the second order with rotating kinematic pairs in the form of angles of moving links, free vectors constructed on these links and radius vectors of characteristic points of the mechanism as a function of the angle of rotation of the master crank. The geometrical parameters of the flat six-link mechanism of eyelets for the warp knitting machine containing the structural group of the fourth class of the second order with rotating kinematic pairs as a result of metric synthesis of the mechanism by random search in CAE-program are determined; computer circuit modeling of the obtained mechanism is performed; graphs of visualization and animation of the kinematic scheme of the received mechanism are constructed; identification of the kinematic scheme of the obtained mechanism for compliance with the accepted structure; the received graph of function of position of an auricular needle of the mechanism of the fourth class; the functions of the position of the eye needle of the new mechanism and the mechanism of the basic knitting machine OV-7 are compared. The structure of a flat six-link mechanism, containing structural groups of the fourth class of the second order with rotating kinematic pairs, is proposed for use as a drive in a warp knitting machine on the example of the mechanism of oscillating movement of eyelets. The geometric dimensions of the moving parts of the functionally adequate mechanism of the fourth class for the drive of the eye needles of the basic knitting machine are determined. Software blocks for automated computer metric synthesis and calculation of link angles and radius vectors of characteristic points of the mechanism in the CAE program have been created. Practical Value is to use the results for the design and construction of flat mechanisms of the fourth class with rotating kinematic pairs of warp knitting machines, in which the working bodies make stops during the work process.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Дворжак, В. М. "ЗАСТОСУВАННЯ МЕХАНІЗМУ ЧЕТВЕРТОГО КЛАСУ ДЛЯ ПРИВОДУ ВУШКОВИХ ГОЛОК ОСНОВОВ’ЯЗАЛЬНОЇ МАШИНИ". Bulletin of the Kyiv National University of Technologies and Design. Technical Science Series 146, № 3 (11 січня 2021): 15–24. http://dx.doi.org/10.30857/1813-6796.2020.3.1.

Повний текст джерела

Анотація:

Development and research of functionally-adequate target mechanisms of technological machines of light industry with application of applied CAE-programs. Used the apparatus of vector algebra; analytical and numerical methods for determining the position functions of planar mechanisms containing a structural group of the fourth class of the second order, based on the vector transformation of coordinates; random search method for metric synthesis of flat mechanisms; methods of computer visualization and animation of kinematic schemes of flat mechanisms of higher classes. Mathematical models describing the position functions of the mechanism of eyelets of a warp knitting machine containing a structural group of the fourth class of the second order with rotating kinematic pairs in the form of angles of moving links, free vectors constructed on these links and radius vectors of characteristic points of the mechanism as a function of the angle of rotation of the master crank. The geometrical parameters of the flat six-link mechanism of eyelets for the warp knitting machine containing the structural group of the fourth class of the second order with rotating kinematic pairs as a result of metric synthesis of the mechanism by random search in CAE-program are determined; computer circuit modeling of the obtained mechanism is performed; graphs of visualization and animation of the kinematic scheme of the received mechanism are constructed; identification of the kinematic scheme of the obtained mechanism for compliance with the accepted structure; the received graph of function of position of an auricular needle of the mechanism of the fourth class; the functions of the position of the eye needle of the new mechanism and the mechanism of the basic knitting machine OV-7 are compared. The structure of a flat six-link mechanism, containing structural groups of the fourth class of the second order with rotating kinematic pairs, is proposed for use as a drive in a warp knitting machine on the example of the mechanism of oscillating movement of eyelets. The geometric dimensions of the moving parts of the functionally adequate mechanism of the fourth class for the drive of the eye needles of the basic knitting machine are determined. Software blocks for automated computer metric synthesis and calculation of link angles and radius vectors of characteristic points of the mechanism in the CAE program have been created. Practical Value is to use the results for the design and construction of flat mechanisms of the fourth class with rotating kinematic pairs of warp knitting machines, in which the working bodies make stops during the work process.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Bulgakov, Volodymyr, Valerii Adamchuk, Ladislav Nozdrovicky, and Ivan Holovach. "Theory of the interaction of flat sensing organ with the head of the sugar beet root." Journal of Agricultural Engineering 48, no. 4 (December 4, 2017): 235–44. http://dx.doi.org/10.4081/jae.2017.676.

Повний текст джерела

Анотація:

Sugar beet leaves now are very widely used for livestock feeding, as an organic fertiliser, and also as a raw material for the production of biogas. Therefore the harvest of the sugar beet tops (including leaves) can be considered as current task for the sugar beet growing system. Modern technologies involve harvest of the tops of sugar beet in two stages: flat basic cut and collecting of the entire green mass at higher altitude and the subsequent cutting of the heads of root crops from the residues. Therefore, topical issues of the sensing of the heads of sugar beet roots arranged in rows, are related to the majority of the sugar beet toppers, cleaners of the sugar beet heads, leaves cutters and, digging up working bodies of some designs. The aim of this study is theoretical determination the optimum design and kinematic parameters of a new sensing mechanism of the sugar beet heads located in the soil on the basis of the theory of interaction of flat passive swath board sensing organ with the sugar beet heads during their topping when located in the soil. In the study there are used methods of creation of mathematical models of functioning of the agricultural machines and their working bodies with the using of main provisions of mathematics, theoretical mechanics, programming and numerical calculations on the PC. In this paper, there is presented a theoretical study of the interaction of passive sensing organ with the head of the sugar beet root when there are located residues of the leaves on a root head spherical surface in the form of short elastic rods. Thus, for such an interaction of the sensing organ and the head of sugar beet root head there is taken into account elastic-damping properties of the sugar beet leaves residues. In the study there was first of all developed a new design of the topper for sugar beet heads with the use of a flat swath board sensing organ, there was developed the equivalent scheme of the interaction of the sensing organ with a fixed sugar beet root head. There was also selected and arranged the axis of coordinates, and determined the active forces and angle parameters. Using the basic law of dynamics there was made up a new system of differential equations and the integration of which has made it possible to find the laws of variation of the speed of movement and of the movement of the flat passive sensing organ on the head of sugar beet root head at the beginning of the contact. After determining the initial values of force and design parameters it is possible to solve them on PC to optimise kinematic and structural parameters of the sensing mechanism.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Eslamirad, Nasim, Soheil Malekpour Kolbadinejad, Mohammadjavad Mahdavinejad, and Mohammad Mehranrad. "Thermal comfort prediction by applying supervised machine learning in green sidewalks of Tehran." Smart and Sustainable Built Environment 9, no. 4 (April 28, 2020): 361–74. http://dx.doi.org/10.1108/sasbe-03-2019-0028.

Повний текст джерела

Анотація:

PurposeThis research aims to introduce a new methodology for integration between urban design strategies and supervised machine learning (SML) method – by applying both energy engineering modeling (evaluating phase) for the existing green sidewalks and statistical energy modeling (predicting phase) for the new ones – to offer algorithms that help to catch the optimum morphology of green sidewalks, in case of high quality of the outdoor thermal comfort and less errors in results.Design/methodology/approachThe tools of the study are the way of processing by SML, predicting the future based on the past. Machine learning is benefited from Python advantages. The structure of the study consisted of two main parts, as the majority of the similar studies follow: engineering energy modeling and statistical energy modeling. According to the concept of the study, at first, from 2268 models, some are randomly selected, simulated and sensitively analyzed by ENVI-met. Furthermore, the Envi-met output as the quantity of thermal comfort – predicted mean vote (PMV) and weather items are inputs of Python. Then, the formed data set is processed by SML, to reach the final reliable predicted output.FindingsThe process of SML leads the study to find thermal comfort of current models and other similar sidewalks. The results are evaluated by both PMV mathematical model and SML error evaluation functions. The results confirm that the average of the occurred error is about 1%. Then the method of study is reliable to apply in the variety of similar fields. Finding of this study can be helpful in perspective of the sustainable architecture strategies in the buildings and urban scales, to determine, monitor and control energy-based behaviors (thermal comfort, heating, cooling, lighting and ventilation) in operational phase of the systems (existed elements in buildings, and constructions) and the planning and designing phase of the future built cases – all over their life spans.Research limitations/implicationsLimitations of the study are related to the study variables and alternatives that are notable impact on the findings. Furthermore, the most trustable input data will result in the more accuracy in output. Then modeling and simulation processes are most significant part of the research to reach the exact results in the final step.Practical implicationsFinding of the study can be helpful in urban design strategies. By finding outdoor thermal comfort that resulted from machine learning method, urban and landscape designers, policymakers and architects are able to estimate the features of their designs in air quality and urban health and can be sure in catching design goals in case of thermal comfort in urban atmosphere.Social implicationsBy 2030, cities are delved as living spaces for about three out of five people. As green infrastructures influence in moderating the cities’ climate, the relationship between green spaces and habitants’ thermal comfort is deduced. Although the strategies to outside thermal comfort improvement, by design methods and applicants, are not new subject to discuss, applying machines that may be common in predicting results can be called as a new insight in applying more effective design strategies and in urban environment’s comfort preparation. Then study’s footprint in social implications stems in learning from the previous projects and developing more efficient strategies to prepare cities as the more comfortable and healthy places to live, with the more efficient models and consuming money and time.Originality/valueThe study achievements are expected to be applied not only in Tehran but also in other climate zones as the pattern in more eco-city design strategies. Although some similar studies are done in different majors, the concept of study is new vision in urban studies.

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Rudas, Imre J. "Intelligent Engineering Systems." Journal of Advanced Computational Intelligence and Intelligent Informatics 4, no. 4 (July 20, 2000): 237–39. http://dx.doi.org/10.20965/jaciii.2000.p0237.

Повний текст джерела

Анотація:

The "information revolution" of our time affects our entire generation. While a vision of the "Information Society," with its financial, legal, business, privacy, and other aspects has emerged in the past few years, the "traditional scene" of information technology, that is, industrial automation, maintained its significance as a field of unceasing development. Since the old-fashioned concept of "Hard Automation" applicable only to industrial processes of fixed, repetitive nature and manufacturing large batches of the same product1)was thrust to the background by keen market competition, the key element of this development remained the improvement of "Machine Intelligence". In spite of the fact that L. A. Zadeh already introduced the concept of "Machine Intelligence Quotient" in 1996 to measure machine intelligence2) , this term remained more or less of a mysterious meaning best explicable on the basis of practical needs. The weak point of hard automation is that the system configuration and operations are fixed and cannot be changed without incurring considerable cost and downtime. Mainly it can be used in applications that call for fast and accurate operation in large batch production. Whenever a variety of products must be manufactured in small batches and consequently the work-cells of a production line should be quickly reconfigured to accommodate a change in products, hard automation becomes inefficient and fails due to economic reasons. In these cases, new, more flexible way of automation, so-called "Soft Automation," are expedient and suitable. The most important "ingredient" of soft automation is its adaptive ability for efficiently coping with changing, unexpected or previously unknown conditions, and working with a high degree of uncertainty and imprecision since in practice increasing precision can be very costly. This adaptation must be realized without or within limited human interference: this is one essential component of machine intelligence. Another important factor is that engineering practice often must deal with complex systems of multiple variable and multiple parameter models almost always with strong nonlinear coupling. Conventional analysis-based approaches for describing and predicting the behavior of such systems in many cases are doomed to failure from the outset, even in the phase of the construction of a more or less appropriate mathematical model. These approaches normally are too categorical in the sense that in the name of "modeling accuracy," they try to describe all structural details of the real physical system to be modeled. This significantly increases the intricacy of the model and may result in huge computational burden without considerably improving precision. The best paradigm exemplifying this situation may be the classic perturbation theory: the less significant the achievable correction is, the more work must be invested for obtaining it. Another important component of machine intelligence is a kind of "structural uniformity" giving room and possibility to model arbitrary particular details a priori not specified and unknown. This idea is similar to that of the ready-to-wear industry, whose products can later be slightly modified in contrast to the custom-tailors' made-to-measure creations aiming at maximum accuracy from the beginning. Machines carry out these later corrections automatically. This "learning ability" is another key element of machine intelligence. To realize the above philosophy in a mathematically correct way, L. A. Zadeh separated Hard Computing from Soft Computing. This revelation immediately resulted in distinguishing between two essential complementary branches of machine intelligence: Hard Computing based Artificial Intelligence and Soft Computing based Computational Intelligence. In the last decades, it became generally known that fuzzy logic, artificial neural networks, and probabilistic reasoning based Soft Computing is a fruitful orientation in designing intelligent systems. Moreover, it became generally accepted that soft computing rather than hard computing should be viewed as the foundation of real machine intelligence via exploiting the tolerance for imprecision, uncertainty and partial truth to achieve tractability, robustness, low solution cost and better rapport with reality. Further research in the past decade confirmed the view that typical components of present soft computing such as fuzzy logic, neurocomputing, evolutionary computation and probabilistic reasoning are complementary and best results can be obtained by their combined application. These complementary branches of Machine Intelligence, Artificial Intelligence and Computational Intelligence, serve as the basis of Intelligent Engineering Systems. The huge number of scientific results published in journals and conference proceedings worldwide substantiates this statement. Three years ago, a new series of conferences in this direction was initiated and launched with the support of several organizations including the IEEE Industrial Electronics Society and IEEE Hungary Section in technical cooperation with IEEE Robotics & Automation Society. The first event of the series hosted by Bdnki Dondt Polytechnic, Budapest, Hungary, was called "19997 IEEE International Conference on Intelligent Engineering Systems " (INES'97). The Technical University of Vienna, Austria hosted the next event of the series in 1998, followed by INES'99 held by the Technical University of Kosice, Slovakia. The present special issue consists of the extended and revised version of the most interesting papers selected out of the presentations of this conference. The papers exemplify recent development trends of intelligent engineering systems. The first paper pertains to the wider class of neural network applications. It is an interesting report of applying a special Adaptive Resonance Theory network for identifying objects in multispectral images. It is called "Extended Gaussian ARTMAP". The authors conclude that this network is especially advantageous for classification of large, low dimensional data sets. The second paper's subject belongs to the realm of fuzzy systems. It reports successful application of fundamental similarity relations in diagnostic systems. As an example failure detection of rolling-mill transmission is considered. The next paper represents the AI-branch of machine intelligence. The paper is a report on an EU-funded project focusing on the storage of knowledge in a corporate organizational memory used for storing and retrieving knowledge chunks for it. The flexible structure of the system makes it possible to adopt it to different SMEs via using company-specific conceptual terms rather than traditional keywords. The fourth selected paper's contribution is to the field of knowledge discovery. For this purpose in the first step, cluster analysis is done. The method is found to be helpful whenever little or no information on the characteristics of a given data set is available. The next paper approaches scheduling problems by the application of the multiagent system. It is concluded that due to the great number of interactions between components, MAS seems to be well suited for manufacturing scheduling problems. The sixth selected paper's topic is emerging intelligent technologies in computer-aided engineering. It discusses key issues of CAD/CAM technology of our days. The conclusion is that further development of CAD/CAM methods probably will serve companies on the competitive edge. The seventh paper of the selection is a report on seeking a special tradeoff between classical analytical modeling and traditional soft computing. It nonconventionally integrates uniform structures obtained from Lagrangian Classical Mechanics with other simple elements of machine intelligence such as saturated sigmoid transition functions borrowed from neural nets, and fuzzy rules with classical PID/ST, and a simplified version of regression analysis. It is concluded that these different components can successfully cooperate in adaptive robot control. The last paper focuses on the complexity problem of fuzzy and neural network approaches. A fuzzy rule base, be it generated from expert operators or by some learning or identification schemes, may contain redundant, weakly contributing, or outright inconsistent components. Moreover, in pursuit of good approximation, one may be tempted to overly assign the number of antecedent sets, thereby resulting in large fuzzy rule bases and much problems in computation time and storage space. Engineers using neural networks have to face the same complexity problem with the number of neurons and layers. A fuzzy rule base and neural network design, hence, have two important objectives. One is to achieve a good approximation. The other is to reduce the complexity. The main difficulty is that these two objectives are contradictory. A formal approach to extracting the more pertinent elements of a given rule set or neurons is, hence, highly desirable. The last paper is an attempt in this direction. References 1)C. W. De Silva. Automation Intelligence. Engineering Application of Artificial Intelligence. Vol. 7. No. 5. 471-477 (1994). 2)L. A. Zadeh. Fuzzy Logic, Neural Networks and Soft Computing. NATO Advanced Studies Institute on Soft Computing and Its Application. Antalya, Turkey. (1996). 3)L. A. Zadeh. Berkeley Initiative in Soft Computing. IEEE Industrial Electronics Society Newsletter. 41, (3), 8-10 (1994).

Стилі APA, Harvard, Vancouver, ISO та ін.

44

"Dynamic model of a longwall shearer with a chain haulage system." Acta Montanistica Slovaca, no. 27 (December 8, 2022): 589–606. http://dx.doi.org/10.46544/ams.v27i3.03.

Повний текст джерела

Анотація:

Despite the pro-ecological policy, hard coal still is and for a long time will remain a valuable major source of energy in the world. It is usually found in the form of seams in underground mines. For many years, thin coal seams have been exploited on an increasingly large scale, therefore mines and machine manufacturers are looking for new, effective and safe methods of extraction. One of such methods is the use of a longwall system with a single-head shearer. This solution has been briefly described in the article, with special focus placed on the proprietary dynamic model of a longwall shearer with a chain haulage system. The model concerns a chain-hauled single-head shearer, but can be used to simulate coal ploughs, and to a certain extent, scraper and belt conveyors. There are models in the literature in which the chain is replaced by point masses. In the discussed model, the chain segments have been described as a continuously distributed mass, the value of which changes as the shearer travels along the wall. The shearer has been modelled as a rigid body with six degrees of freedom, placed on elastic skids. The load from cutting, loading and movement resistance has been taken into account in the model. The mathematical model has been saved in the form of scripts in Matlab. The set of scripts allows obtaining information about the behaviour of the shearer and the load on important structural nodes such as skids, chain and loaders fasteners or the driving shaft of the cutting head. The results also enable determining the power demand of the motors as well as calculating the required initial tension of the chain. The fully parametric model makes it possible to analyse the influence of a change in the values of significant parameters of the longwall working, drive units and shearer. This information is crucial at the stage of design construction and verification, which allows avoiding many errors in the prototype.

Стилі APA, Harvard, Vancouver, ISO та ін.

45

"DEVELOPMENT OF A UNIVERSAL AUTOMATIC CONTROL SYSTEM FOR TECHNOLOGICAL PROCESS OF HOLE PROCESSING WITH A MULTI-TOOL." АГРАРНЫЙ ВЕСТНИК ВЕРХНЕВОЛЖЬЯ, March 15, 2020. http://dx.doi.org/10.35523/2307-5872-2020-30-1-114-119.

Повний текст джерела

Анотація:

The industry serially produces hydraulic power heads, tables designed for drilling, countersinking and boring holes. The disadvantage of these power heads is that they are not universal in terms of the impossibility of rapid changeover from the drilling operation to the reamer. At the same time, two methods of processing holes with multi-blade tools are implemented. The first one is drilling holes in solid metal with a drill, in which the cutting tool experiences heavy loads, leading to premature wear and breakage. The second one is boring of the obtained holes after technological operations of drilling and countersinking, which leads to increased energy costs and labor of operators. The existing fleet of drilling machines, as a rule, is not equipped with automatic control systems of technological processes, allowing to ensure the quality of hole processing at high productivity. The article presents the original universal two-circuit scheme of automatic control of technological processes of drilling and reaming holes. The system controls the technological processes of drilling holes by switching the appropriate taps in the application of hydraulic power heads and improves the quality of processing and tool life. With the help of General transfer functions and according to the Raus - Hurwitz criterion, its stable operation is achieved both during drilling and deployment. The derived mathematical models make it possible to perform calculations to determine the mass-geometric and regime parameters necessary for the design and creation of automatic systems for controlling the modes of operation of hydraulic power heads.

Стилі APA, Harvard, Vancouver, ISO та ін.

Статті в журналах з теми "Cutting machines Design and construction Mathematical models"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями