articles
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№ 5(107)
25 october 2023 year
Rubric: Researching of processes and systems Authors: Kurilin S., Fedotov V., Kultygin O. |
The determination of indicators of the technical quality of electric motors, as well as their modeling, are in demand in the organization, final control of the technical quality of products, in the procedures for diagnosing and monitoring the technical condition of electrical equipment during operation. A large role in substantiating the criteria for the technical quality of electric motors and developing methods for their determination is given to computer modeling. Along with rotating electric motors, linear asynchronous electric motors (LAEM) are increasingly being used in technical systems. Criteria and test methods developed for rotating electrical machines are not adequate to the specifics of the LAEM. As applied to LAEM inductors, a method is proposed for assessing the technical quality indicators of three-phase inhomogeneous inductors with a non-uniform distribution of magnetic properties along the magnetic circuit. The method is based on the impulse effects of a voltage source on the LAEM inductor. A mathematical model, an algorithm and a program for modeling the technical quality indicators of LAEM inductors that implement the proposed method have been developed and presented. The program is written using its own interpreted programming language of the Maple software product and requires the user to enter the parameters of an electrical device. At the output, the user automatically receives an image of the Green’s matrix, oscillograms of phase currents based on the results of three experiments, and numerical values of quality indicators. The simulation results indicate that the proposed method can serve as a tool for the technical control of inductors, and also that the developed technical quality criteria, mathematical model, algorithm and program allow modeling and evaluating the technical qualities of LAEM inductors both during final tests and during monitoring the technical condition of the device during operation. Continue... |
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№ 5(107)
25 october 2023 year
Rubric: Researching of processes and systems Authors: Blinov A., Borisov V. V., Konchina L., Maslova K. |
Mathematical modeling of an active exoskeleton in the form of an electromechanical model containing three movable, controlled links interconnected by hinges has been carried out. For the considered mathematical model of the active exoskeleton, differential equations of motion are proposed. Numerical methods are used to solve the inverse and direct problems of dynamics in the created software package in the environment of the universal system of computer mathematics. A comprehensive study has been carried out, considering the problems of exoskeleton control, in the form of solving inverse and direct problems of dynamics, in relation to the created mathematical model of three moving parts of the exoskeleton, taking into account electric drives, using modern methods of mathematical modeling. Analytically determined are the angles between the links that define the anthropoid movement. Solving the inverse problem of dynamics, the moments controlling the movement of the links are calculated for each electric drive. The found moments are approximated by stepwise piecewise-constant functions simulating the impulse control of the exoskeleton motion. Dependences of the angular coordinates describing the positions of the links of the active exoskeleton over time are found. A comparative analysis of the numerical solution of the Cauchy problem for the mathematical model of the exoskeleton in the form of differential equations with the initial, given movement of the links is carried out. A good agreement between the results of simulation with impulse control and the original motion is established. The total energy costs have been calculated. Modeling is carried out taking into account the presence of electric drives: dynamic equations for this model are compiled. The Cauchy problem for the system is numerically solved taking into account the presence of electric drives. As a result of applying qualitative, analytical and numerical methods for studying the created mathematical model of three moving parts of the exoskeleton, taking into account the presence of electric drives, the significance of the influence of electric drives on the dynamics of the mechanism was established. The implementation of the electromechanical model of the three links of the exoskeleton was carried out in the environment of the universal system of computer mathematics “Wolfram Mathematica 11.3”. Continue... |
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№ 6(108)
25 december 2023 year
Rubric: Authors: Makarovskikh T., Abotaleb M., Dernova O., Maksimova V. |
Both in Russia and in other countries, scientists note the need development of artificial intelligence methods for precision farming. However, the software nowadays used for this purpose is only developing and sometimes not released for sale, and the methods stated in individual articles use standard approaches, which leads to significant errors. Another reason is a non-trivial way of obtaining initial data, in particular, as a result of the analysis of satellite images, which is a rather laborious work and is possible only if there is a database of the objects under study with their specified geographical coordinates. The article discusses the development of a system for predicting the yield of agricultural land using satellite images. The system includes both classical methods (for example, the parabolic regression discussed in the article) and approaches developed by the authors to identify the parameters of the quasi-linear equation of n-factor autoregression. Despite the presence on the market of a fairly large number of software products for precision farming, many of the existing software and approaches are not intended to provide data for further analysis by specialists who are not employees of the developer company. As for our system, the collection and subsequent analysis of aerial photography data is carried out, which consists in building a model of the dynamics of the vegetation index, which is subsequently used to predict the yield of the field in the following periods. The proposed system is extensible, i. e., it allows connecting additional modules for analysis and inclusion in the analysis of additional factors that affect the indicator under study. The article describes the data presentation method, the process of calculating vegetation indices for a certain date, and also provides mathematical approaches to modeling the vegetation process using high-quality deterministic mathematical models and predicting the next season’s crop yield and production costs. Continue... |
| Digital counterparts of business processes in modern conditions are used not only to analyze the process, but also to optimize its execution. The presence of feedback from the real process makes it possible to create effective automated solutions for the execution of the constituent elements of the process. In this scientific study, an improved mechanism for managing elements of an instance of a real business process using its digital counterpart is proposed. The proposed mechanism is based on the implementation of software for the orchestration of the API component call in the workflow and the orchestration of RPA robots in the logical and structural layer of the virtual representation of the digital twin of the business process. RPA robots simulate human actions on a computer by interacting with various software applications, processing data and performing operations. Orchestration, in turn, allows the orchestrator, a software or system component, to manage the sequence and flow of tasks, resources and data within the process. Since in practice, business entities, among others, solve the problem of developing and applying digital twins of reference and original business processes, this study also presents a conceptual scheme for developing a digital twin of a business process. The issues of designing a virtual business process model, at the cyber-physical level, the level of extraction and preprocessing, the level of models and algorithms, and the level of visual representation of the digital counterpart of the business process are also investigated. The benefits of running a business process using its digital counterpart include increased error reduction, faster process execution, improved quality, and the ability to easily make changes to the process in response to changing requirements. This is especially useful in modern organizations where efficiency and flexibility in managing business processes are required. Continue... | |
| Modern economy is characterized by mass production and introduction of production services within the digital ecosystems that assist the customer in obtaining the final results, in particular, organization of procurement of radio-electronic components. The relevance of the task of optimal inventory rating control is related to development of a service that minimizes risks arising from uncertainty of such factors as receipt of requests for commodity and its supply, supplier’s prices and selling prices, etc. The issues of development of economic and mathematical models of inventory rating optimization applicable to the specific features of vertically integrated companies and legally independent organizations operating in conditions of the market economy on kanban principles are considered. It is shown that in conditions of uncertainty, use of ratings allows to increase the efficiency of the inventory control system. The possibility of presentation of the inventory control system in the form of an evolutionary simulation model is substantiated. The procedure is provided to bring the task of inventory rating to the canonical form of an evolutionary simulation model (ESM). The peculiarities of the inventory control systems are revealed using the examples of “Stock” ESM for VIC and “Zapas” ESM for independent companies. The methods are determined for calculation of the derived rates: the average number of supplies, the average interval between supplies, etc. The contribution of the authors of the article consists in development of the ESM applicable to inventory rating, which combines the simulation models (estimates of the actual overstatement and understatement cost options relative to the planned radioelectronic components inventory rate, as well as estimates of the expected costs (risks) obtained in statistical tests) with the optimization models implemented based on the theory of equilibrium random processes. The aggregate strategy, i.e. the strategy aimed at minimizing the amount of the overstatement and understatement risks is used as a criterion for inventory rating. The experimental studies of “Stock” and “Zapas” models implemented using the “Equilibrium” module of the author’s system – “Decision” allow real-time modeling of various options of the studied rates. Continue... | |
| The article shows the problem of reducing the efficiency and quality of the formation of control actions by the head of the class when preparing groups of specialists to perform complex tasks agreed on time, place and goals in organizational and technical systems of various purposes due to the influence on the psychophysiological capabilities of the head of the class of increasing the density of the flow of incoming information at the stages of working out the interaction between groups of specialists in a single virtual space. The use of intelligent methods to solve this problem is substantiated and a method of scenario-information analysis of adaptive training of groups of specialists is proposed, the essence of which is to build a scenario-information model of adaptive training based on a fuzzy ontological approach, taking into account the availability of resources, the current state of specialists (current level of preparedness) and precedent scenarios of adaptive training for subsequent modeling of this process and estimates of its achievability under various preparation scenarios. A fuzzy ontological approach to modeling adaptive training of groups of specialists using granulation of information resources is proposed, which makes it possible to organize the training process more efficiently, including in conditions of limited time and material resources. The results of experimental studies on improving the level of preparedness of group specialists through intelligent management of their adaptive training are shown. Continue... |
