Complex Technical System Research Articles

Solving the problem of stability of the stationary quality indicator of complex technical systems

Aim. To define and solve the problem of stability of the stationary quality indicator of a complex technical system. The random process of the system’s walking by its possible states is described with a homogeneous Markov process. The stability problem consists in defining such stationary (final) probabilities of the Markov process that implement the maximum and minimal values of the quality indicator, provided that the rate of state transitions have interval estimations and the rates are conditioned by the process of failures and recoveries of the system’s elements. The stationary quality indicator has a fairly standard form and is a scalar product of the final probability vector of the Markov process and the vector that characterises the “weight” of each state, where “weight” may be understood as various contensive characteristics of states.Methods. The paper uses mathematical methods of optimal control of a Markov process using an income vector of a special form and linear programming.Results. A method is proposed and substantiated for solving the problem of stability of a stationary indicator of the quality of operation of a complex technical system. A numerical algorithm for solving the above problem is presented as well. The paper gives an example of the solution of a problem of stability with quality indicator that is a “penalty” function.Conclusion. The paper discusses the problem of numerical solution of the stability problem of a large dimensionality.

Algorithm for Calculating Reliability of Single Linear Section of Steel Underground Pipeline

One of the most widespread technical systems in the world is underground steel pipeline communications (heat pipelines, main and distribution oil and gas pipelines, etc.). Accordingly, reliability assessment of such technical systems and their components is of great theoretical and practical interest. At the modern level of development, reliability calculation has become a mandatory stage in the design and diagnostics (during operation) of any technical systems in ge-neral, and in particular pipeline systems. A reliable calculation, either explicitly or implicitly, is always based on the model of the object being calculated. It is the adequacy of the model to the real physical relations and processes inside the technical object that determines the accuracy and practical value of calculation methods. It is proposed to consider a single linear section of an underground steel pipeline as a complex technical system of unequal elements from the point of view of reliability – the main element (steel pipe) and auxiliary protective elements combined into subsystems (blocks). The algorithm for calculating the reliability of the object is based on the method of block diagrams, taking into account the influence of the aftereffect of the failure of an auxiliary element (elements) on the reliability parameters of the main element, which more adequately reflects the specific features of the design and operation of steel pipelines compared with the applied static models. The variants of structural design of a steel underground gas pipeline with a protective insulation coating and with complex corrosion protection (insulation and electrochemical protection) are considered, for which refined formulas are obtained for calculating the main reliability (failure-free) indicators.

Life cycle management of the ventilation system of a construction object

Introduction. In the article, the author considers a mechanical ventilation system as a complex technical system that can be effectively controlled based on a model of its life cycle. Like any engineering system (or product, product, project), a ventilation system has its own life cycle, consisting of a set of successive stages. Each stage is characterized by its own types of work and final results that require management decisions.Materials and Methods. The paper uses the method of analyzing the life cycle of complex technical systems, methods of collecting and processing statistical data, as well as methods of systematic and comparative analysis, generalization of scientific and practical results.Results. In the course of the conducted research, the author applied the "life cycle management" approach to ventilation systems and achieved the goal of developing a model of their life cycle, which includes all stages of system development from conception to disposal. Possible ways of managing the life cycle of ventilation systems from the perspective of continuous interconnection of processes are determined.Discussion and Conclusion. Effective life cycle management of a mechanical ventilation system can be implemented through the development of a software product capable of modeling processes and system elements even at the first stages of the life cycle. The software product should eliminate the existing problem of inconsistencies at different stages of work, store information about the object and provide access to it for each participant in the process. Solving the problem of creating a software product will ensure effective management of the entire life cycle of the ventilation system, reduce labor costs and inconsistencies and ensure compliance with modern requirements for operational reliability and energy efficiency of a vital engineering system.

N-version programming for nanosatellite telemetry processing

Software is a key element that ensures the functioning of any modern complex technical system. One such system is the constellation of spacecraft and associated ground control complexes that provide reception, transmission, and processing of collected telemetry. The process of data acquisition and its subsequent processing is critical to the flight control of the spacecraft and its onboard scientific equipment. Furthermore, telemetry data processed by ground control systems involves large volumes of raw data, the processing of which is a complicated and time-consuming task. In order to solve this problem, various methods of automatic data processing are used. Improving them is a key factor in ensuring the fault tolerance of onboard software and hardware, improving its reliability. Of all the existing widely-used methods of data processing, we shall focus on N-version programming (NVP) approach. N-version programming has firmly established itself as an effective method for increasing software reliability and designing fault-tolerant systems. Since its inception in the 1970s, this approach has been deeply connected with the development of aerospace software systems, including, among others, satellite ground control stations. In light of the aforementioned, this paper discusses the application of NVP for processing telemetry data gathered from nanosatellites (CubeSats). Due to the fact that there exists a skeptical view on the NVP approach in terms of its efficiency, the author covers this issue in existing literature in terms of the approach’s applicability for processing satellite telemetry.

APPLICATION OF THE SCENARIO APPROACH TO THE ANALYSIS AND CONTROL OF RISKS IN THE OPERATION OF COMPLEX DYNAMIC SYSTEMS UNDER CONDITIONS OF INTERVAL UNCERTAINTY

Introduction. The paper provides a description of the scenario approach to risk control in the operation of complex technical systems under conditions of uncertainty. The scenario is understood as the optimal control action on the system parameters, which allows minimizing the possible costs associated with the implementation of the corresponding risk event.
 The aim of the study is to develop effective risk management methods for the operation of a complex dynamic system under conditions of uncertainty based on a scenario approach that makes it possible to implement the optimal control action on the parameters of an object in the event of a threat of an emergency.
 Materials and methods. The article describes the application of the scenario method to the management of risks that arise during the operation of a complex dynamic system under conditions of interval uncertainty. This approach is based on the application of methods of interval analysis and the theory of situational management.
 The scientific novelty of the implemented approach lies in the use of the interval analysis apparatus, which makes it possible to most correctly take into account the possible errors associated with measuring the values of the system parameters and apply the optimal control actions necessary for correction in the event that the permissible indicators go beyond the operability area.
 Discussion and conclusion. The mathematical model of risk control developed in the course of the study carried out during the process of functioning of a complex technical system under conditions of interval uncertainty based on the scenario approach allows the selection of optimal control actions (scenarios) that allow minimizing possible errors and inaccuracies that arise due to deviation from the calculated nominal values.

Software for Animation and Graphic Visualization of Mechatronic Elements and Control Process of FMS

The issue of graphical visualization of the simulation, animation and design of mechatronic elements and control process in the example of the mechanical assembly shop of the flexible manufacture system (FMS), which is considered a complex technical system, is set. The purpose of the work is the development of graphics-mode software that provides computer experiments of 2D, 3D designer-modeling, animation and graphic visualization of the interface for evaluating the feasibility of the design process of the flexible mechanical assembly cell (FMAC) As the main research issues, the construction of the 2D and 3D grouping scheme of the static and dynamic elements of the research object, the development of 3D software for the animation models of the activities of its active elements, and the development of the generalized software for the graphic visualization of the interface for the design of the management system were set. Based on the issues raised, the 3D grouping scheme of static and dynamic elements of the FMAC was established, the positioning coordinates of the 2D static and dynamic elements of the FMAC were determined in the PROOF Animation system, the analysis of the technological process of the FMS was carried out to build an animation model, and the animation movements of technological operations were MOVE (management unguided movement) or PATH (guided movement) operators. An animation model of the static and dynamic active elements of the FMAC was built, experiments were conducted, and as a result, it was possible to calculate a technological cycle in the research object and determine the productivity of the workshop. The software for the graphic visualization of the design of the control system of the FMAC was developed, and the procedures and operations of each software module of the interface were planned.

METHODOLOGICAL APPROACHES TO ASSESSING THE LEVEL OF MANAGEMENT OF ECONOMIC SECURITY OF ENTERPRISES

The article presents the results of research on the generalization and formation of the main provisions of methodological approaches to the assessment of the level of management of the economic security of enterprises in accordance with modern globalization changes. Criteria for assessing economic security have been determined. It is noted that the development of the system of criteria and parameters characterizing the degree of protection of the enterprise from negative influences is based on a number of proposed principles. The comparative characteristics of the methods of quantitative assessment of the level of threats based on the conditions of application, assessment, accuracy of assessment, costs, accounting for the impact of individual threat factors have been carried out. It is justified to use an approach that reflects the principles and conditions of program-target management and development, which is based on the integration of a set of indicators that determine economic security, to assess the economic security of the enterprise. It was concluded that in an effort to assess the state of such a complex technical and economic system, which is a modern enterprise, which functions in the conditions of the interaction of many internal and external factors, which often have an unpredictable effect on the process of development, production and sale of products, only based on formalized calculations can lead to results that are completely inconsistent with the real state of the enterprise and its development prospects. The proposed model of the interaction of components for assessing the level of management of economic security of enterprises, as a basis for making appropriate management decisions. as well as assessments of the company’s priorities based on the analysis of the state of the level of economic security of the company. In order to adapt the process of economic security management to changing conditions, it is necessary to carry out an effective analysis of solving tasks aimed at improving the functioning of the enterprise.

Plowing operation: labor productivity and specific operating costs. Part 1. Multifactor simulation of plowing operation

One of the most important problems in grain production in the Republic of Belarus is increasing labor productivity, which is 4–5 times less than labor productivity in the EU countries. A great influence on labor productivity and specific operating costs is exerted by energyand material-intensive operations, such as plowing and harvesting. The main patterns of the plowing operation, which is a complex technical system, is connected with the use of a large volume of agrotechnological, technical, operational, resource and economic information (operation duration, working length of the harrow, physical and mechanical properties of soil, depth of treatment, permissible interval of the unit speed, fuel and energy, engine power and traction characteristics, width of the unit, economic indicators, etc.) are considered. Currently, as a result of introduction of computer mathematics systems, there are effective methods available for studying complex technical systems, allowing for multi-factor modeling and multi-criteria optimization of the production processes and formation of a set of machines by system analysis. A prerequisite for a complete and comprehensive description of the functioning of a complex technical system is the presence of conflicting optimization parameters, as well as a complete set of independent control factors significantly affecting these parameters. A distinctive feature of the proposed method is to determine not one optimal solution, but a set of Paretooptimal solutions, giving the producer new opportunities of choice when organizing the production processes, increasing the efficiency of plowing operation and, consequently, the profitability of grain production in general. Therefore, increasing productivity at permissible specific operating costs through the formation of a rational set of machines and modes of its operation under specific conditions of production is an important scientific and engineering task. A mathematical illustration of the method is provided for natural-production conditions of the Republic of Belarus.

The development of a method for assessing the security of complex technical systems using artificial immune systems

Ensuring the security of complex technical systems of various functional purposes requires a constant search for new scientific and practical approaches in order to ensure its proper level against a growing list of new risks and threats. Nowadays, no state in the world is able to work on the creation and implementation of artificial intelligence in isolation from others. Artificial intelligence technologies are actively used to solve both general and highly specialized tasks in various spheres of society. The problem of synthesis of management of complex technological processes is an urgent task in management theory. A promising direction in the design of such complex ones is the use of bio-inspired algorithms that are effectively used while solving optimization tasks. Thus, the object of research is complex technical systems. The subject of research is the state security of complex technical systems. The research developed a method for assessing the security of complex technical systems using artificial immune systems. The novelty of the proposed method consists in: ‒ taking into account while calculating the correction factor for the degree of uncertainty about the state of a complex technical system; ‒ reducing computing costs while assessing the state of a complex technical system; ‒ improved implementation of procedures for solving the task of influencing relationships in a complex technical system; ‒ creating a multi-level and interconnected description of hierarchical complex technical systems; ‒ the possibility of performing calculations with source data that are different in nature and units of measurement. It is advisable to implement the mentioned technique in specialized software, which is used to analyze the state of complex technical systems and make decisions.

THE OPTIMAL DESIGN OF THE 40.00-57 DUAL PURPOSE ORTHOTROPIC SHELL UNDER UNCERTAINTY CONDITIONS DESIGN

Problem statement. A feature of the modern technical systems’ design is that deterministic approaches dominate, while consideration of uncertainty can provide a more adequate representation of the research object in the appropriate calculation scheme, mathematical model. The consideration of uncertainties becomes especially relevant in the modeling of complex technical systems, where uncertainties can be quite abundant and the uncertainties themselves can be of different nature, namely stochastic, rough, fuzzy, or even combined. It is advisable to check whether the system is tolerant to uncertainties. This work is devoted to the construction of methods for the optimal design of the new rubber-cord shell 40.00-57 in the conditions of the fuzzy initial data. For a deterministic approach a special mathematical model can be used to calculate the output parameters. The mathematical model developed by Prof. E. Kvasha, at one time was truly revolutionary, because for the first time in the world the contact problem of the interaction of an elastic base with a layered orthotropic shell, which is part of a complex technical tire system, was solved. The main drawback, which could not be overcome by varying the input parameters, remained the uneven resource of the shell frame elements. So, variant design has shown its insufficient efficiency for such complex technical systems. The purpose of the research is to suggest a model and methods of optimal design for optotropic rubber-cord oversized shells under the conditions of real factors of uncertain nature. Conduct methods testing and design a new construction of tire 40.00-57 for civilian and military purposes. Conclusion. The authors proposed models and methods of optimal design of orthotropic rubber-cord shells under the condition of fuzzy data. Approbation of the symbiosis of Monte Carlo methods and the method of local variations for finding the optimal geometry of the shell was conducted. For new 40.00-57 tire shape, the difference between the largest frame resource and the smallest resource of the tire’s elements was about 18 %. Such a result could not be achieved by variant design. The temperature distribution in the cross-section of the tire under conditions of operation for 8 hours at an ambient temperature of 37 0C does not exceed the value of 110 0C, at which the thermal destruction of the rubber-cord material begins.

Оценка технологического потенциала деталей

The article describes a methodology for assessing the technological potential of parts, based on the sociophysical theory of potentials and dimensional analysis of the technological process. The technological potential of a part acts as a system characteristic of a complex technical system. The program A'PROPOS was chosen as a tool for calculating the technological potential. A hypothesis has been put forward that the technological potential of the part is associated with the complexity of the technological process of manufacturing this part. It is possible to evaluate it using dimensional analysis using CAD tools. Methods and materials. The emergence and creation of fundamentally new technologies is considered a historical process of development of the designed technical system, in this case, the DSE. The technological potential of the part is formed as the technological process is implemented. The value and structure of the potential are determined and consistent with the properties of the designed part. Based on the results of the analysis of the technological process of manufacturing a part, the construction of a sketch of a part in A'PROPOS., the technological potential is calculated using a mathematical model. The potential is calculated on the basis of the initial data of the enterprise for the object of study. Result. Based on the constructed model, the technological process is optimized. The result is a new machining plan containing the compositions and accuracy of the surfaces machined in the stages and the minimum allowance. Based on the model with variations of dimensional relationships, the dimensional structure is improved to expand the tolerance fields with guaranteed maintenance of technological parameters. Based on this, the deviation in the recommended labor intensity is calculated compared to the real one. Next, the accumulated technological potential of the part was calculated. Conclusions. The system makes it possible to iteratively perform technological calculations, as well as integration with CAD systems in the enterprise. When calculating the technological potential, instead of using the initial data of the enterprise, it is interpreted by the adequacy of the model.

Formalization of risk management in the context of digital business transformation

The aim of the article is to develop a formal methodology for quantitative assessment of the quality of аcontrol in a closed system with feedback in the context of digital transformation. In the proposed study, attention is focused on assessing the quality of management in organizational and technical systems on the example of the aviation industry. The following hypotheses were adopted in the study: in the digital management of business processes of an economic entity, the role of intellectual support is acquired by methods of formal description of processes: control, decision-making and corrective action on the control object. In critical situations, the psychotype of the person making the decision acquires a decisive role. The study solves two scientific and practical problems: development of a formal method for quantitative assessment of the quality of management of a complex multi-criteria organizational and technical system under the conditions of statistical uncertainty of management agents, taking into account feedback in the management of an object; formalization of the process of quantitative assessment of decision-making risks in the environment of statistical uncertainty of control agents and psychological factors of the decision maker.

Structural Adaptation of the Safety Control Program of the Technical State of a Complex Technical System

Structural Adaptation of the Safety Control Program of the Technical State of a Complex Technical System

Power Transformer Condition-Based Evaluation and Maintenance (CBM) Using Dempster–Shafer Theory (DST)

Transformers are the most important elements in the power system. Due to their mass and complexity, they require constant monitoring and maintenance. Maintenance of power transformers increases the availability of the power system. The large number of substations and the specifics of their locations make condition-based maintenance (CBM) useful as part of the system's on-demand response. Unlike other system responses, the transformer contains a large amount of uncertain information, both qualitative and numerical. A large amount of information is necessary to implement CBM, but due to the often incomplete information, an analysis tool is essential. In this paper, a multi-level condition assessment framework based on evidential reasoning is proposed. A model for condition-based maintenance of a power transformer and procedures for the aggregation process based on evidential reasoning are presented. The implementation of the decomposition model with appropriate weights of a baseline and general attributes was made. Based on the decomposition model, the data and ratings of baseline attributes were collected. By carrying out the aggregation process, the ratings of the baseline attributes, as well as the ratings of the condition of the individual elements and the overall rating of the system condition as a whole, for several points in time, were obtained. The scientific contribution of the work is the proposal of an analysis that provides an insight into the condition of a complex technical system based on a single numerical value, thus determining its priority in the maintenance process.

Intellectualization of search for the causes of failure of components of a complex technical system

Intellectualization of search for the causes of failure of components of a complex technical system

Validation of Reliability Indices during Experimental Development of a Complex Technical Series System

Introduction. The article studies the problem of validating the specified levels of reliability during experimental development of a complex technical series system. Such tasks arise when it is required to make a decision on testing the system as part of a larger one or on the completion of experimental development and the start of series production. The study is aimed at validating the reduction of the experimental development time. The task is to determine whether the hypothesis Но is accepted or rejected.Materials and Methods. To implement the research objective and task, a critical area described by the inequality was constructed based on the test results. The formulation of the requirements validation task was based on well-known approaches to testing statistical hypotheses. The conceptual apparatus of information theory, probability, and statistics was involved. The theoretical and applied literature on mathematical methods in reliability theory was studied. The particular tasks of the work were solved by known ways. Thus, the probability of obtaining the exact number of successful outcomes in a certain number of experiments was determined by the Bernoulli scheme. The exact confidence interval based on the binomial distribution was derived from the Clopper-Pearson relation. The theorem of A.D. Solovyov and R. A. Mirny made it possible to assess the system reliability based on the test results of its components.Results. Control rules adequate to the stage of experimental development (with insufficient data on the technical system) and the stage of series production were mathematically defined. The probability of a successful outcome when testing technical systems was represented by:– the probability of event for a system element;– confidence value;– required scope of tests.In these terms, the null and alternative hypotheses and the corresponding reliability control procedures were investigated. Two provisions were considered. The first one provided using the null confidence hypothesis Но = {Р ≥ РТ} and an alternative Н = { Р < РТ} to confirm the requirements (РТ, γ) for the reliability indicator of one parameter for any (РТ, γ). In this case, one trouble-free test was enough. The second provision considered a sequential technical system with independent elements that were tested separately from the system according to the Bernoulli scheme for one parameter. We considered the requirements for the system in the form of a set of values (РТ, γ) and the requirements for any of its elements (РТi, γ). They coincided when the planned outcome of the tests corresponded to the cases when the ratio Р= lim 1≤i≤N : Р i = Р m was fulfilled, and the null alternative hypothesis was selected from the theory of statistical hypothesis testing.Discussion and Conclusions. The experimental development strategy should be implemented in two stages: the search and validation of the reliability of the elements through a series of fail-safe tests. In this case, the planned scope of tests of each element is determined taking into account the confidence probability, the lower limit of the confidence interval, and the requirements for reliability indices of one parameter of the technical system. If the use of the null confidence hypothesis is acceptable, one fail-safe test is sufficient to confirm the requirements for the reliability index.

Применение теории статистических гипотез в задачах автоматизации технологических процессов

The paper substantiates the application of methods of the theory of statistical hypotheses for the tasks of automation of technological processes. The functioning of the process automation system is considered as the management of a complex technical system. The operation of the automation system belongs to the multi-alternative in terms of the theory of statistical hypotheses: two hypotheses of the correct mode and two hypotheses of the erroneous operation of the system. The article provides general expressions for calculating the probabilities of these modes for two statistical models of the controlled parameter of the technological process and standard models of the metrological spread of the measuring channel. In this case, the accuracy class of the measuring channel should be expressed as a reduced error. The simulation of the operating modes of the process automation system is carried out within the framework of the theory of statistical hypotheses. The results of modeling for the normal probability density of the statistical model of the controlled quantity, uniform and triangular statistical models of estimation of the controlled parameter are presented. A program of statistical evaluation of the modes of operation of the automation system has been developed for symmetric and asymmetric statistical models of the spread of the controlled parameter and several models of metrological spread of the evaluation of the technological parameter. The calculation of the a priori probability of the normal functioning of the automation system of the technological process and the calculation of the a priori probability of erroneous operation of the automation system is given. Expressions for calculating a posteriori probability of the results of verification of measuring instruments of automation systems are obtained.

ПРОГРАММНО-АППАРАТНОЕ МОДЕЛИРОВАНИЕ КОМПЛЕКСИРОВАННОЙ ИНЕРЦИАЛЬНОЙ НАВИГАЦИОННОЙ СИСТЕМЫ НАЗЕМНОГО ОБЪЕКТА

The purpose of this paper is creation of an efficient software and hardware model of a groundmobile object navigation system. Simulation process is one of the key instruments for engineering solutionsdevelopment at all stages of a complex technical system lifecycle. Navigation system model describedin this paper is software-hardware by nature and is implemented as software modules that supporthardware interaction with each other. The described system of ground object navigation systemsimulation has been developed in the course of several design projects and scientific research works.The developed model of a ground mobile object navigation system includes several programming units.Each of these units simulates the operation process as close as possible to the original. Internal andexternal interaction interfaces and navigation system communication protocols are also simulated withthe account for real object operation cyclograms. It should be noted that one of the main advantages ofa software simulation over a developmental testing or breadboarding is the opportunity to perform aprofound analysis of operation algorithms without the use of any additional resources. At the same time,it is often necessary to perform firmware design in order to make the simulation process identical withthe real operation. The process of navigation system architecture simulation allows performing a comparativeanalysis of several base components sets and their interaction patterns. Such comparison resultsin an optimal system structure providing the information user with navigation data in the mostefficient way. The paper determines basic simulation process tasks. The simulation stage may becomecrucial for complex systems design as it may aid achieving the best technical result. The proposed structure,key elements of a ground navigation simulation system and approaches to their interaction arrangementhave been approved in the course of several research and development works. At the sametime, it was found that the validity of developed models and their compliance to simulated units allowsperforming a highly reliable navigation system analysis. The developed software-hardware model allowedprocessing telemetry records obtained under different product operation conditions, performingtheir analysis and developing engineering solutions that increase the efficiency of navigation systems.

Methodology for assessing the effect of ultrahigh-frequency electromagnetic radiation on the devices of a maintenance-free complex technical system

Methodology for assessing the effect of ultrahigh-frequency electromagnetic radiation on the devices of a maintenance-free complex technical system

Обзор проблемных вопросов создания мультироторного летательного аппарата для исследования Венеры

The paper considers problematic issues that could arise in the process of studying design situations when creating a multirotor aircraft, which was first proposed as the technical means in studying the planet Venus as part of the promising Venusian spacecraft. The course of work identified a number of critical situations that should be analyzed already at the early stages of designing and developing the multirotor aircraft being a complex technical system in Venus exploration and taken into account when developing a program for its direct operation on the planet. The summary matrix of problems was compiled for visual presentation of the study results. This matrix reflects the probable problem situations in implementing the experiment scheme in the Venus atmosphere and surface contact study. For this purpose, the multirotor aircraft was decomposed into subsystems, and main stages of its operation were considered in the Venus atmosphere.