The article presents the results of checking the adequacy of the method of online diagnostics and automated control of the technical condition of the electromechanical drive of the KP21 mining machine with an asynchronous squirrel-cage motor, proposed earlier by the authors. The method of experimental production studies provides for the connection of the measuring complex to the stator winding of one of the phases of the electric motor. The measurements were carried out under various operating conditions of the combine, corresponding to various technical conditions of the facility. A comparative analysis of the technical condition of the diagnosed nodes and the values ​​of the normalized amplitudes of the corresponding frequencies led to the conclusion: the defect must be fixed if the signal amplitude exceeds the value of 10% of the maximum, and the defect is significant and needs to be eliminated if the amplitude value exceeds 30%. To use the obtained research results in practice, an integral nomogram of the correspondence between the operating time of the combine harvester and the amplitude - frequency characteristic of the stator current of the drive motor of the cutting body is proposed. The results obtained are taken as a basis for correcting the schedule of preventive maintenance and maintenance of the cutting body of mining machines KP21 when operating in the appropriate mining and geological conditions.

Keywords: reliability of mining equipment, online diagnostics, automated control, current monitoring, maintenance and repair

This article gives an overview of the operation of dehumidification plants located in indoor ice arenas. Since at the moment the operation of such facilities does not include control of such parameters as CO2 content, the possibility of implementing this task using the existing equipment is considered. A method of setting the automatics of maintaining the CO2 level in the set parameters is given. The principle of dehumidifier operation and problems of CO2 level control are considered. The method of tuning the control loops is also described. The use of CO2 controlled dehumidifier equipment will create comfortable conditions for the occupants of the ice arena, which in turn will lead to a reduction in energy and heat consumption.

Keywords: automatic control system, control loop, control object, process stabilisation, air drying, air drying plant

The study evaluated the effect of the spring position in the panel on the amount of force required for vertical pushing of the columns. The results show that the farther the spring is from the hinge, the less pushing force is required to lift the column. In this method, the column was connected to the panel by hinged hinges at the factory, which allows lifting elements by crane as a single group during the installation of the frame structure on the construction site. In addition, a spring is installed on the panel at a certain distance, helping to push out the column and secure it. In this article, a threaded connection of precast reinforced concrete columns is proposed, which can be used to connect elements of fully assembled buildings and structures. The contact-screw connection of precast reinforced concrete consists of an upper and lower column, both have a cylindrical steel external thread in the end section connected. The strength of the screw column connection is determined by ensuring the transmission of axial loads and torque in the joints, ensuring the destruction caused by cutting and thread confusion that may occur between the connected columns. By means of the necessary calculations for the screw connection of columns made of precast reinforced concrete the corresponding rigidity and strength were confirmed. The new connections will contribute to the development of construction, its energy efficiency and acceleration of the installation process. These are effective approaches to reducing effort, time, and labor and energy costs.

Keywords: prefabricated buildings, passive assembly, column connection, screw connection, energy efficiency of installation, mounting spring, hinge loop

The work updates a strategic approach to maintaining the quality of student performance. In the article "Big Data" is presented as an approach to organizing the data obtained during the educational process. Mining analysis as a Big Data analysis tool. The authors also considered approaches to improving the effectiveness of learning, which allow predicting student performance. Blended learning, as an integration into the educational process, the best opportunities for online and distance learning, provided for the subsequent collection of Big Data for analysis. The application of data mining methods for the development of models for predicting the behavior and academic performance of students is considered. The authors propose student modeling as a key concept in data mining in education, which refers to the qualitative representation of student behavior. Algorithms for data mining are described, classification and clustering are presented as the most common tasks. The CART decision tree algorithm is presented as one of the effective data mining methods needed to predict student performance based on online activity that is stored in the Moodle LMS log file. Finally, it was concluded that the personal contact of an experienced teacher with a student in the educational process can not be replaced by the tools provided by Moodle and similar systems, but due to the growing threats caused by the pandemic, the relevance of distance education is becoming increasingly important.

Keywords: student performance quality, big data, data mining, student modeling, CART decision tree algorithm, Moodle LMS, distance education

The article is devoted to the development of models and algorithms for calculating control (advisory) actions when training operators of technological processes (on the example of reloading processes and, in particular, portal cranes) on computer training complexes (CTC). A complex of models and algorithms is proposed, based on which control actions are calculated regarding discrete crane controls and the possibility of moving the load to a target position with minimization of oscillations at the end point is provided. These models and algorithms use variable parameters of the technological process, described by linguistic variables, and customizable characteristics of crane models and engines, which allows calculating control actions depending on the type of crane, the specifics of the technological process, the training methodology used for operators and other significant factors. Application of the advisory system based on the developed models and algorithms promotes to improve the training process for operators of reloading cranes at CTC and, as a result, to reduce the probability of emergency situations, reduce time and energy costs.

Keywords: computer simulator, reloading processes, portal crane, advisory system, control actions, mathematical modeling, fuzzy logic controller

The control of the fabric in the technological chain determines the structure of this very chain. The article uses a probabilistic model to assess the feasibility of re-processing fabric in finishing production.

Keywords: fabric, marriage, quality, batch, product, technological defect, reprocessing, profit, loss

This article discusses the development of a control and measuring system for reading barcodes from printed circuit boards in the production process. A functional diagram of the device was designed. A full-scale experiment was carried out to determine the working distance and angles for reading barcodes. It was revealed that the developed system has competitive advantages over analogues in a higher barcode reading speed and work with different barcode inclination angles.

Keywords: control and measuring system, bar code, printed circuit boards, laser range finder

The problem of increasing energy efficiency remains one of the most important for industries and human activity today. The construction industry is one of them.The problem of the construction of energy-efficient multi-storey residential buildings is closely related to the quality of construction control. The article discusses the main stages of the implementation of possible defects in the enclosing structures of a multi-storey residential building. The systematization of defects is given and the causes of their occurrence are presented. Solutions are also proposed to reduce the negative impact of poor-quality construction control of enclosing structures for the purpose of further study.

Keywords: construction control, energy efficiency, enclosing structures, multi-storey buildings

Ecology is an acute problem in the modern world. At many enterprises and in many processes, they strive to reduce emissions of waste and natural gases that have a negative impact on the environment. The author of the article suggests using energy-efficient technologies in housing construction, namely, when carrying out major repairs of apartment buildings in the city of Moscow. In this article, the author considers technologies that reduce power consumption, which can also be applied during major repairs. In particular, an important role for reducing emissions of harmful substances into the environment is the reduction of heat consumption in apartment buildings. The result of the introduction of the technologies listed in the article will be an improvement in the standard of living in the old housing stock.

Keywords: capital repairs, city environment, factors, building, energy efficiency, heat loss, apartment building, ecology, emissions, waste

The global economy growth and active industrial development are limited, among other things, by the capabilities of existing technology. The potential for improving the functional characteristics of classical materials is practically exhausted, and the widespread use of new composite materials and high-enthalpy alloys is limited by the high cost and complexity of the technological process of their manufacture and processing. Knowledge of the materials physical-mechanical, thermophysical and chemical characteristics proves that the surface structural-phase state in many cases is crucial in the processes of wear, fracture, chemical and thermal destruction. Thus, the issue of developing technologies and equipment for modifying the surface layer and creating multicomponent coatings, including nanocomposite ones, is urgent. Current article presents the results of a study devoted to the creation of a facility for such coatings deposition by plasma spraying. One of the key elements of technological equipment for this method is a vacuum chamber, which is exposed to intense thermal stress during operation. Thus, the issue of designing a cooling system is relevant. To reduce the material and time resources at the design and experimental development, the temperature state of the chamber was simulated. It is shown that to ensure safe operation, it is advisable to use water cooling. The simulation results confirm the operability of the vacuum chamber cooling system under operating conditions. The following operating parameters were determined: the inlet pressure is 0.6 MPa, the water flow rate is 2 l/s, and the mass average temperature of the outlet water is about 40°C.

Keywords: plasma spraying, thermal state simulation, vacuum chamber, cooling system

Due to the constant increase in production, new structural materials development and growing rates of non-renewable resources consumption, the issue of increasing the machinery resource is urgent. Thus, it is necessary to develop technologies for spraying coatings that improve the functional characteristics of products, in particular, impact strength, microhardness, resistance to wear, corrosion and other environmental factors by modifying the surface layer structural-phase state. These technologies application is necessary in strategically important industries, such as machine tool manufacturing, aerospace, automotive, shipbuilding, chemical, energy, etc. This article is devoted to the facility development for multicomponent nanocomposite coatings sputtering. The design and commissioning of such a facility requires a high time and material resources investment. In this regard, it is necessary to use modern computer software systems that allow simulating multiphysics processes that take place during the facility operation. The simulation of the cathode-anode unit was carried out. Based on the simulation results it was shown that it is necessary to take into account the physical processes in the interelectrode region when designing the plasma spraying unit, since the resource of the cathode-electrode unit and the productivity of the sputtering process directly depend on the parameters of the discharge and the resulting plasma jet. Thus, high temperature and current density, as well as the arc spot abrupt movement, lead to increased wear and failure of the copper nozzles. The maximum values of the temperature and velocity of the plasma jet during spraying were 32000 K and 1800 m/s, respectively.

Keywords: plasma spraying, multicomponent nanocomposite coatings, multiphysics processes, mathematical modeling

The article raises an urgent problem for large cities - the fight against the negative consequences of road transport. The importance of urban planning measures to reduce the accumulation of emissions, as well as green spaces to reduce the concentration of dust content of harmful substances in urban areas is considered. The data of CO concentration near the mainline territories in 95 studied points were analyzed.

Keywords: road transport, dust, gas-protected green areas, leaves, green spaces

This paper presents an information model of a relational database developed by the authors, designed to take into account the teachers workload of an educational organization. The identification of the subject area entities, their decomposition and the relationships identification between them are carried out. The constructed database model was brought to the Boyes - Codd normal form. Based on the designed database schema, its physical implementation and filling with test data was carried out. The results of test queries showed the developed model adequacy and the its practical applicationp ossibility. It is currently in trial operation at the Department of Information Systems and Computer Modeling, Volgograd State University. With minimal changes, the developed database schema can be applied to account for the teachers workload in various educational organizations.

Keywords: database, information modeling, "entity-relationship" diagram, decomposition, information system, educational organization

Carbon formation in diesel engines affects an increase in the temperature of the sleeve, a decrease in the thickness of the oil film, an increase in oil fumes, which causes more intensive wear of the piston group cylinder parts. According to the theory of heat exchange, the heat flow from the working fluid (combustion products) is directed perpendicular to the surface of the piston bottom and is proportional to the equivalent temperature to the average heat transfer coefficient per cycle. Heat can also be supplied to the side surface of the piston bottom, but since the thermal gap between the piston head and the cylinder is small, the heat flow is insignificant. The deposition of carbon deposits on the bottom of the piston and cylinder head causes a slight decrease in its temperature, but at the same time the temperature of the cylinder liner increases, which causes a change in the gaps of the "piston-sleeve" interfaces. Experimental determination of interface gaps on a running engine is associated with significant difficulties. As a result, a computational and theoretical analysis of changes in the magnitude of thermal gaps was performed with a decrease in the thickness of the carbon layer on the bottom of the piston. The deposition of carbon deposits on the bottom of the piston indicates less favorable operating conditions of the piston-sleeve conjugations due to an increase in the dynamic performance of the cycle.

Keywords: quality, surface, part, performance properties, roughness, friction, wear, research, processing, physical and mechanical properties, hardening, deformation

The article discusses the issue of creating an automated system for detecting defects on tissue based on the use of computer vision. The resulting system makes it possible to control, register and calculate defects in textile materials without human participation in the technological process, which improves the quality of analysis, eliminates the number of errors in fabric sorting and reduces the cost of the technological operation.

Keywords: automated system, defect detection, textile material, computer vision, microcomputer, image processing library