Solution of the compromise optimization problem of network graphics on the criteria of uniform personnel loading and distribution of funds

Domina, Olena

doi:10.15587/2706-5448.2021.225527

Cited by 2 publications

(1 citation statement)

References 13 publications

(18 reference statements)

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“…It is natural to assume that with such an approach, all temporary operations of the processes must be coordinated. That is, the prevention of downtime, in particular due to the lack of metal of the required quality, can be achieved by optimally distributing the execution of technological operations and resources for their implementation [29,30]. The latter may include energy costs.…”

Section: Engineeringmentioning

confidence: 99%

Experimental and industrial method of synthesis of optimal control of the temperature region of cupola melting

Demin¹

2023

Eureka: PE

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The object of research is the temperature regime of melting in a cupola. The synthesis of optimal control of such an object is associated with the presence of a problem consisting in the complexity of its mathematical description and the absence of procedures that allow one to obtain optimal control laws. These problems are due to the presence of links with a pure delay, non-additive random drift, and difficulties in controlling the process parameters, in particular, accurately determining the temperature profile along the horizons and the periphery of the working space of the cupola. The proposed conceptual solution for the synthesis of optimal temperature control allows the use of two levels of control: the level controller solves the problem of maintaining the constant height of the idle charge, and the problem of increasing the temperature of cast iron is solved by controlling the air supply to the tuyere box. It is shown that the problem of regulating the upper level of an idle charge can be solved by reducing the model of the regulation process to a typical form, followed by the use of the Pontryagin maximum principle. A procedure for the synthesis of optimal air flow control is proposed, which makes it possible to obtain the temperature regime control law on the basis of experimental industrial studies preceding the synthesis process. This takes into account the time delay between the impact on the object and its reaction, which makes it possible to predict the temperature value one step acharge, equal to the time interval during which the lower surface of the fuel charge reaches the upper surface of the level of the idle charge. A procedure for temperature profile control based on the use of D-optimal plans for selecting sensor installation points is proposed. Due to this, it becomes possible to determine the temperature profile of the cupola according to its horizons and the periphery of the working space of the cupola with maximum accuracy. The proposed synthesis method can be used in iron foundries equipped with cupolas, as it is a tool for studying a real production process, taking into account its specific conditions. This will allow developing or improving control systems for cupola melting, implementing different control modes: manual, automated or automatic

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Section: Engineeringmentioning

confidence: 99%

Experimental and industrial method of synthesis of optimal control of the temperature region of cupola melting

Demin¹

2023

Eureka: PE

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Construction of a logical-probabilistic model of casting quality formation for managing technological operations in foundry production

Demin,

Frolova

2024

Eureka: PE

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The object of the study is the quality of castings manufactured in disposable sand molds. The problem associated with the limitations of existing studies focusing only on individual components in assessing the quality of castings was solved. This imposes restrictions on the use of the results of such studies in the context of quality management of finished castings in industrial production. The hypothesis of the study assumed that it is possible to build a model of casting quality formation, on the basis of which technological operations that form casting defects can be identified, and a choice of control for such technological operations can be made. A procedure for constructing a logical-probabilistic model of quality formation is proposed, in which the output variable is the integral criterion for assessing the quality of castings, and the input variables are the quality indicator of the j-th technological operation. The input and output variables are linked by the logical operation "AND" and can take two values – "0" and "1". Therefore, taking into account the sequence of technological operations that form the quality of finished castings, if the value of the l-th quality indicator of a casting in the j-th technological operation falls outside the tolerance field, taking into account the permissible amount of defects, then the value of the quality indicator of the technological operation is taken to be 0, otherwise 1. Thus, if the quality indicator of the j-th technological operation takes a value of 0, then the integral criterion for assessing the quality of castings is also equal to 0 and a search for control is required to ensure the achievement of the specified requirements for this quality indicator. It is shown that the search for control of the technological operation, during which the casting defect was formed, allowing to ensure the specified requirements for the corresponding quality indicator of the casting, is possible on the basis of the transformation of mathematical models, for example, of the "composition – properties" type, built on the "black box" principle. The considered virtual example for cast iron casting "flanged valve body" allowed to draw a conclusion about the practical applicability of the proposed procedure in foundries of industrial enterprises.

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Solution of the compromise optimization problem of network graphics on the criteria of uniform personnel loading and distribution of funds

Cited by 2 publications

References 13 publications

Experimental and industrial method of synthesis of optimal control of the temperature region of cupola melting

Experimental and industrial method of synthesis of optimal control of the temperature region of cupola melting

Construction of a logical-probabilistic model of casting quality formation for managing technological operations in foundry production

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