ПЕРСПЕКТИВНЫЕ МОДЕЛИ ОЦЕНКИ ТЕХНИЧЕСКОГО СОСТОЯНИЯ ТОРМОЗНЫХ СИСТЕМ ВЫСОКОАВТОМАТИЗИРОВАННЫХ ТРАНСПОРТНЫХ СРЕДСТВ

In order to objectively evaluate the level of GEC and understand all the aspects and internal mechanism of GEC, a comprehensive evaluation of it is necessary, which requires establishment of an indicator system that can objectively and precisely reflect the various aspects of GEC while at the same time looking at the internal structural characteristics of it and can evaluate and analyze it using scientific and logical mathematical evaluation model. Owing to the extensive contents covered by GEC, including ecological environment, resource environment, environmental management, environmental influence and environmental coordination, and the unique internal structural characteristics, it is a rather complex task to establish an indicator system and mathematical model used for evaluation, analysis and research of the GEC. This study has explored to design a scientific and proactive evaluation indicator system and model with reasonable logics and wide visual field and at the same time fitting into the reality of global environment based on the environmental status and facts of 133 countries of the world and their environmental development objectives.KeywordsAnalytic Hierarchy ProcessEnvironmental SystemEcological EnvironmentResource EnvironmentIndicator SystemThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

The paper describes the application of the author’s mathematical model of gas-dynamic processes for a marine piston engine based on a computer program. The developed mathematical and numerical model is designed to conduct simulation diagnostics. Therefore, it is possible to carry out calculations for motors in different technical conditions and observing influence of changes in technical condition on selected parameters of its work. Simulation of changes in technical condition is carried out by modifying parameters of structure’s model object. The article contains a detailed description of each options of the computer program. From the main program window, user can select type of engine model (supercharging method, cylinder number, work order, stroke and piston diameter and a number of other parameters). Through a window of simulation of known and recognizable damages such as: change in fuel dose for each cylinder, change in intake and outlet valves, leakage of piston-ring-cylinder system, change of injector hole cross section. Final windows show results of calculations in form of mileage parameters of engine as a function of crank angle.

To ensure the efficient operation of vehicles, first of all it is necessary to have continuous and safe operation of their units by improving the reliability and quality of diagnosis. The drive axle of the car is an important unit that is designed to transmit torque from the engine to the wheels of the vehicle. Transmission units must operate in all modes of operation of the vehicle. Loss of serviceability of the drive axle leads to loss of serviceability of the car as a whole. In this regard, the technical condition of this unit must be subject to increased requirements, and it is necessary to conduct systematic monitoring, which gives a clear idea of the current technical condition of the drive axle and the ability to predict the failure of this transmission unit. The existing methods and tools for diagnosing of driving truck axles do not fully determine their current technical condition, which requires the development of mathematical models to automate the process of diagnosing their components and parts was found іn the analysis of literature sources. Mathematical model of automation of the process of diagnosing of driving axles of KAMAZ cars is presents in the article. Replacing real technical devices with their idealized models allows the widespread use of various mathematical methods. In this case, the drive axle of the KamAZ cars, as the object of diagnosis, is presented in the form of a «black box», the input and output parameters of which have a finite set of values. In general, the mathematical model is a system of functional relationships between each diagnostic signal and structural parameters. For driving axles of KAMAZ cars, a diagnostic matrix has been compiled, which includes a list of faults and signs of faults. It is determined that the process of diagnosis based on the model of the diagnostic object is possible if the inverse transformation of the number of signs of malfunctions into the number of structural parameters (malfunctions) of the object was unambiguous. The proposed mathematical model of automation of the process of diagnosing of driving axles of KAMAZ cars will detect faults of components and parts depending on their characteristics.

Hybrid energy systems combine several energy sources: solar panels, wind turbines, mini-hydropower plants, fossil fuel sources (diesel generators). These energy sources complement each other in order to ensure uninterrupted power supply to consumers regardless of weather conditions and time of year. With the continuously increasing complexity of hybrid systems, the interaction between logical components and continuous physical processes described by a particular kind of mathematical models becomes relevant. It is therefore an important task to predict the remaining lifetime of hybrid renewable energy systems during their operational phase. This problem has to be solved, for example, when replacing equipment that has reached its end of life and when extending its service life. The aim of the research is to develop a mathematical model and tools for residual life assessment of hybrid systems with renewable energy sources. Controlling the technical condition of systems involves assessing changes in diagnostic parameters. The choice and justification of the function describing the process of parameter change is an important point in the development of forecasting methods.The choice of the approximating function ultimately determines the error and labour intensity of forecasting. The relations for the wear model of the hybrid system with renewable energy sources based on the assumption of the automodel of this process are obtained. In the general case, the process of changing the system parameters can have areas of both deceleration and acceleration of wear. A mathematical model for predicting the residual life of a hybrid system with renewable energy sources based on the results of observations of its condition during operation is proposed. This method allows to organise preventive maintenance and repair of the system taking into account its current technical condition, which will reduce operating costs.

The analysis of the organization of training of personnel on equipment indicates the imperfection of calculations of the needs of equipment to achieve the qualitative goal of training, respectively, the ineffective use of forces and means. There are systemic omissions in the background of the organization of the technical condition recovery system, high-quality planning and forecasting of the main failures of the technical condition, thereby an imperfectly thought-out data processing system for the provision of spare parts for equipment, information about which should be available on the interfaces of computer workstations of logistics officials for carrying out routine repairs to replenish resource reserves in order to carry out timely maintenance of equipment by the forces of full-time drivers in accordance with their functional duties. It is the principle of prevention that is the most important criterion in building a system, which can be depicted using the method of typical operators through an operator model for planning activities involving military equipment for training personnel in training support units and makes it possible to calculate the preliminary required amount of equipment using a mathematical model, with the condition for understanding the declared as necessary in terms of quantity for the high-quality implementation of the planned event without disruptions, and provides an approximate situational vision, namely, distribution of flows of weapons and military equipment by type of state, failures, accompanied by the operation of combat vehicles by personnel who are practically not familiar with the order of the equipment attached to it. Keywords: distribution of flows of weapons and military equipment by type of state, failures, maintenance, operation of combat vehicles, technical condition, restoration, operator model, mathematical model, method of typical operators, data processing, background, interface of computer workstation.

New Approach To The Formation Of The Adequate Diagnostic Matrix Of The Gas Turbine Engine

The paper is aimed to create the mathematical model of the centrifugal compressor based on the group method of data handling-type neural networks to determine the compressor volumetric flow rate as the dependence on the centrifugal compressor’s technological parameters (the rotor’s angular velocity, the compressor’s inlet and outlet temperatures, the compressor’s inlet and outlet pressures, the atmospheric pressure). It is the important scientific task, because most centrifugal compressors used in the process industry don’t have equipment needed to measure the volumetric flow rate. It does not allow to estimate the compressor’s technical state during its operation. Verification of the developed model has been performed, based on the 336 data points (collected from the field measurements) and with using the centrifugal compressor of natural gas (16ГЦ2-395/53-76C) of Dolyna linear production administration of gas transmittal pipelines. The test results have been showed the adequate efficiency of the mathematical model. Keywords: volume flow, centrifugal supercharger, mathematical model, method of group consideration of arguments, neural networks, technological parameters, correlation coefficient.

Introduction. The article examines the influence of the current technical condition of electrical equipment on the reliability of power supply systems. Currently, there is little or no statistical information available that would help establish the dependence of failures in elements of power supply systems on the occurrence and development of defects in the details of these elements when monitoring their condition. In addition, there are also no mathematical models that could show the connection between these events in the equipment. Goal. The purpose of the work is to develop mathematical models for modeling and accounting for the current technical condition of elements of power supply systems in reliability calculations. Materials and methods. A mathematical model is proposed that allows taking into account the current technical condition of electrical equipment in reliability calculations. The mathematical model is based on a heuristic method of obtaining information, the weighting coefficients of significance obtained during the examination are used in the model. The examination was carried out by employees of the company of the object in question. A mathematical model has been developed to generate the values of the current technical condition of the elements and to model the weight coefficients of the condition, to account for defects in the elements of the power supply system when calculating reliability. Results and discussion. The presented mathematical models were implemented in the form of a software package for automated calculation of the reliability of the power supply system and generation of values of the current technical condition based on the Monte Carlo method. To calculate the reliability of the considered power supply schemes, the main reliability indicators of the elements were used, obtained on the basis of statistical information on failures of electrical equipment over 10 years of operation. Conclusion. The calculation of circuit reliability for the consumers in question has been performed, and the current technical condition for their elements has been simulated. A comparison of reliability estimates with and without taking into account the current technical condition is given.

This paper proposes an approach to automotive starter diagnostics based on comparing the results of mathematical modelling with experimental data obtained on the ASG-019 diagnostic test bench. A simplifi ed mathematical model of the starting mode is developed, describing the time dependences of the supply voltage, armature current, electromagnetic torque, and shaft angular acceleration. The model is implemented as a software tool with a graphical interface for visualising transient processes. The purpose of the study is to develop an informative mathematical model of the starter starting mode and to analyse electromechanical processes under transient conditions with the possibility of comparing theoretical and experimental characteristics. Methods of mathematical and computer modelling using numerical signal processing are applied. The implementation is carried out in Python using the NumPy and Matplotlib libraries and the Tkinter interface. The model adequacy is evaluated by qualitative comparison with experimental data obtained on the ASG-019 test bench. Results. Time dependences of the supply voltage, armature current, electromagnetic torque, and shaft angular acceleration are obtained, refl ecting the main stages of the starting process, including the initial current peak, transient voltage drop, and subsequent dynamic acceleration of the electric motor. The theoretical characteristics enable assessment of the infl uence of electrical circuit parameters and mechanical load on the shape of the starting curves. Comparative analysis with experimental data from the ASG-019 bench demonstrates qualitative agreement in the shape and time structure of the signals, as well as reproduction of the main trends of current and voltage variation under transient conditions. Conclusions. The proposed mathematical and computer model adequately represents the general nature of the electromechanical processes during automotive starter starting. The observed quantitative discrepancies between theoretical and experimental characteristics are explained by the adopted simplifi cations, in particular neglecting inductive parameters, mechanical losses, the effect of the solenoid relay, and the actual characteristics of the battery. The results confi rm the feasibility of the proposed approach for diagnosing the technical condition of the starter and provide a basis for further refi nement of the model to improve the accuracy of starting characteristic evaluation.

Twenty-four U.S. states have enacted HIV exposure laws that prohibit HIV-positive persons from engaging in sexual activities with partners to whom they have not disclosed their HIV status. There is little standardization among existing HIV exposure laws, which vary substantially with respect to the sexual activities that are prohibited without prior serostatus disclosure. Logical analysis and mathematical modeling were used to explore the HIV prevention effectiveness of two types of HIV exposure laws: "strict" laws that require HIV-positive persons to disclose their serostatus to prospective partners prior to any sexual activity and "flexible" laws that require seropositive status disclosure only prior to high-risk sex (e.g., unprotected anal or vaginal intercourse). These laws were compared relative to each other and to a no-law alternative. The results of these analyses indicate that, under most (though not necessarily all) circumstances, both strict and flexible exposure laws can be expected to reduce HIV transmission risk relative to the no-law alternative, with flexible exposure laws producing the greater reduction in risk. This study demonstrates how logical analysis and mathematical modeling techniques can make an important contribution to the construction of a rational basis for decisions about a highly contested public health policy issue.

The article discusses the issues of modeling conditions for obtaining diagnostic information about complex objects. As an example, the study of the braking qualities of four-wheel drive cars on an inertial roller stand is considered. Diagnosing the technical condition of cars from the point of view of traffic safety is one of the most important problems. This is especially important for systems whose technical condition affects traffic safety: especially braking systems. Foreign and domestic experience testifies to the effectiveness of instrumental control. The diagnostic equipment includes roller stands, on which you can check the braking properties of cars. As shown by many studies, in particular, carried out at the Department of Technical Operation and Service of Automobiles, KhNADU (HADI), inertial stands provide more reliable information about the technical condition of the car. Such stands allow you to reproduce the real speed and thermal modes of the brakes (especially those equipped with ABS). To improve the accuracy of diagnosing a car on a roller stand, it is necessary to have an idea of the nature of the interaction of the car wheels with the rollers. The studies of wheel rolling on the stand rollers have been carried out by many authors since the 80s of the last century. However, all these studies were carried out on uniaxial stands and for mono-drive vehicles. Nowadays, a large number of passenger cars have four-wheel drive. Rolling of the wheels of such cars on rollers and their interaction has practically not been studied. Therefore, a return to the study of this issue is relevant. A power model of the system of interaction between the car and the stand has been developed, taking into account the design features of the stand and the design features of the car's suspension. The power model of the system under consideration contains the equilibrium equations of the body and two bridges and the equations of motion of the rollers and wheels of the car. Based on the results of the analysis of the acting forces in the "car-stand" system, the braking moments on the wheels M and the coefficients of the use of the load q during the braking tests of a 4x4 vehicle were determined. The obtained research results allowed to improve the theory of interaction of a car wheel with the rollers of an inertial diagnostic stand.

The object of this study is the processes of perception and redistribution of loads in the supporting structure of a open wagon loaded with containers, taking into account the new scheme of their fastening. For safe transportation of containers in an open wagon, it is suggested to use a removable module. This module works according to the principle of an intermediate adapter between the container and the open wagon body. Fastening of the module itself in the open wagon is carried out through the fitting stops, which are placed on the floor of the open wagon. Mathematical modeling was carried out to determine the longitudinal dynamic load acting on the container fixed according to the new scheme in the open wagon. To this end, a mathematical model was built that characterizes the longitudinal movements of the "open wagon - removable module - container" system. Determination of the accelerations that act on the supporting structure of the open wagon loaded with containers was also carried out by means of computer simulation. Verification of the formed model of the dynamic load of the open wagon was carried out according to the F-criterion. Also, as part of the study, a modal analysis of the load-bearing structure of a open wagon loaded with containers was carried out, which made it possible to assess its traffic safety. A feature of the results obtained as part of the research is that the proposed design of the removable module could be used not only for fastening containers but also for transportation of other types of cargo. The field of practical application of the results is railroad transport, including other transportation industries. The conditions for the practical use of the results are a symmetrical scheme of loading the body of a open wagon with containers. The results of this study will contribute to increasing the efficiency of container transportation and the profitability of railroad transport

Purpose. There is a need of wear process modeling in the wheel-rail system. This is related to the fact that the wear processes in this system are absolutely different in the initial and final stages. The profile change of rail and, especially, of the wheels caused by the wear significantly affects the rolling stock dynamics, traffic safety and the resource of the wheels and rails. Wear modeling and the traffic safety evaluation requires the accounting of the low frequency component forces (including the modeling of transitional areas) affecting the wheel on the side of the rail and carriage in motion of rolling stock, so the statistical analysis is not possible. Methodology. The method of mathematical modeling of the wheel set and the rail interaction was used during the research conducting. Findings. As a result of the modeling of the wheel set motion on the rail track, the mathematic model with 19 freedom degrees was obtained. This model takes into account the axle torque and studies wheels constructions as the components of the mechanical systems, consisting of a hub and tire. Originality. The mathematic model allows evaluating the wear degree of the wheels and rails when using on the rolling stock not only all-metal wheel sets, but also compound ones with the use of spring wheels and independent rotation of semi-axes with the wheels. Practical value. The development of the improved mathematical model of freight car wheel set motion with differential rotation of the wheels and compound axles allows studying the wear processes of wheels and rails.

BackgroundNew mathematical models of complex biological structures and computer simulation software allow modelers to simulate and analyze biochemical systems in silico and form mathematical predictions. Due to this potential predictive ability, the use of these models and software has the possibility to compliment laboratory investigations and help refine, or even develop, new hypotheses. However, the existing mathematical modeling techniques and simulation tools are often difficult to use by laboratory biologists without training in high-level mathematics, limiting their use to trained modelers.ResultsWe have developed a Boolean network-based simulation and analysis software tool, ChemChains, which combines the advantages of the parameter-free nature of logical models while providing the ability for users to interact with their models in a continuous manner, similar to the way laboratory biologists interact with laboratory data. ChemChains allows users to simulate models in an automatic fashion under tens of thousands of different external environments, as well as perform various mutational studies.ConclusionChemChains combines the advantages of logical and continuous modeling and provides a way for laboratory biologists to perform in silico experiments on mathematical models easily, a necessary component of laboratory research in the systems biology era.

When planning the operation of land transport and transport technology facilities, their technical condition is not sufficiently taken into account. This can lead to unplanned failure of the machines and failure of the planned work by the remaining machines. The proposed methods of distributing machines by objects and types of work are based on the theory of aging of machines, but unlike the performance potential of machines, which reflects the technical condition of an average machine, they are focused on a specific machine, the probability of failure of which is determined using technical diagnostic methods. The results of the study of the dependence of the probability of failure of the car on the value of the inter-control period, the patterns of change in the probability of failure during the inter-control period and with an increase in the mileage of the car are presented. The goal is to increase the efficiency of the use of ground transportation and transportation technology facilities. Method and methodology. The theory of aging of machines, mathematical modeling, statistical methods of analysis. Results. New dependences of the probability of a car failure on the value of the inter-control period, the regularity of the change in the probability of failure during the inter-control period and with an increase in the mileage of the car are obtained and justified. The field of application of the results is the operation of ground transportation and transportation technology facilities.