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The article describes three variants of the mathematical model of the sensitivity function of the magnetoinduction sensor for assessing the influence of various sensor parameters in the electromechanical system «wheel - rail - magnetoinduction sensor» for diagnosing the technical condition of the rolling surface of the rolling wheels of rolling stock in the process of its movement over the sensor. An example of an algorithm for identifying defects located on the surface of the wheel rolling circle is described. The proposed multi-vector mathematical model allows simulating various defects on the rolling surface of the wheel, developing and testing new algorithms for processing the output signal of the sensor on the basis of modern hardware and software. The implemented defect identification algorithm is based on the property of the centrally symmetric form of the sensitivity function of the magnetoinduction sensor and the allocation of a useful signal corresponding to a certain type of defect, based on the application of a mutual correlation function and the assessment of its maximum and minimum values in comparison with the specified thresholds and confidence intervals. The main requirement for the implementation of the model is the uniform movement of the train above the sensor along a straight section of the rail track. This article discusses only one of the possible digital signal processing algorithms, but the proposed model allows us to compare the efficiency of other possible algorithms identification of defects in the rolling surface of wheelsets. The developed model confirms the prospects of using magnetic induction sensors for identification of not only visible, but also hidden defects on the rolling surface of the wheel in the process of movement of the train.

The paper deals with the problem of the presence of thermal inertia in thermoelectric converters of general industrial design, used to measure temperature in most technological installations with an ambient temperature above 200 ° C. The aim of the study is to develop an algorithm for predicting the temperature of the environment with known thermal characteristics of the temperature sensor and to implement the algorithm directly in a general industrial programmable logic controller (PLC). As the main method, the work uses the method of mathematical modeling and description of the object in transfer functions and in the form of differential equations. The work uses a previously developed engineering technique for determining the thermal inertia time of industrial sensors, based on a single disturbance and an assessment of the dynamic characteristics of an object. On the basis of the research and mathematical modeling, algorithms for predicting the temperature of the medium by the parameters of the thermal inertia of the temperature sensor and the rate of change of the thermocouple signal have been developed and implemented. The implementation of the algorithms in the TIA Portal environment based on the Siemens Simatic S7-300 PLC using the PID Control library is proposed.

The problem of optimizing train driving modes continues to be relevant for a long time, despite a large number of scientific research and development in this subject area. This is due both to the general complexity of the implementation of the technological process of running the train, and to parametric uncertainty and significant variations in the parameters of the control object itself and the external environment. Well-known methods for calculating energy-optimal train driving modes (calculus of variations, the maximum principle, dynamic programming) and auto-driving systems based on them assume some simplifications of the original problem, and, as a result, implement quasi-optimal control in practice. In this regard, the development of methods for searching for the global extremum of a functional defined on the set of permissible trajectories of a train as a dynamic system is both theoretically and practically a significant task. The aim of the work is to create a computationally efficient metaheuristic algorithm for searching for energy-optimal control as a global extremum of the objective function, the values of which are calculated using a reference model of the control object. The authors have developed a problem-oriented evolutionary algorithm for calculating the optimal control of train movement based on the theory of random search. Its features are the proposed specialized operators of local random search, taking into account the specifics of the control object as a multi-mode system; combined procedures of local and global optimization based on the concept of a multi-island population algorithm with superpopulation, as well as a method of selection (selection) of promising options based on the clustering algorithm. Computational experiments have shown good convergence of the algorithm and repeatability of the calculation results. Based on the solutions obtained, a train running time controller can be implemented that implements asymptotically optimal control.

To improve the accuracy of the diagnosis of the technical condition of rolling stock, it is necessary to develop new algorithms for the digital processing of signals coming from sensors at the time of the passage of the axes of wheeled pairs of wagon carts during the uniform movement of the train on the straight section of the railway track. The use of modern mathematical application software packages to model digital-based data processing algorithms reduces the cost and time of developing automated systems to diagnose the technical condition of the rolling stock of railways. To assess the accuracy of the fixation by the magneto-induction sensor of the moment of passage of wheel pairs axly, an asthigmatic model is proposed, allowing to investigate not only the energy properties of the sensor, but also the shape of the output signal, taking into account the real dimensions of its magnetic core. The developed model allows you to classify the pore. The developed model allows to classify the order of astigmatism model magnetoinduction sensor based on a set of discrete virtual sensors

The article discusses the operation of systems for interval regulation of train traffic based on a digital radio channel in the absence of radio communication. The aim of the study is to determine the maximum allowable time for the absence of radio communication between the radio blocking center and a moving train in the interval control system. Criteria are proposed that allow assessing traffic safety, as well as reducing the throughput of train traffic in interval control of train traffic systems. The results of calculating the maximum permissible time of radio communication absence in interval control of train traffic systems for freight trains are obtained. Taking into account the maximum allowable time for the absence of radio communication will completely eliminate the likelihood of a dangerous convergence of trains and ensure compliance with the allowable speed mode with a minimum interval of freight trains.

The article presents the results of research of a point magneto-induction sensor based on a mathematical model, which allows you to increase the reliability of automated systems for diagnosing technical condition rolling stock in the course of train movement by improvement the accuracy of the initial information, that is, the moments of fixation passing of wheelset axles over magneto-induction sensors. At the first stage of developing a stigmatic mathematical model the analytical dependence of the value of the magnetic flux in the magnetic core and the output EMF value on resistance of the air gap between the sensor and the wheel crest. At the second stage of development of the mathematical model found time dependence of the magnetic resistance of the air gap between the core of the magneto-induction sensor and the comb wheels of a railway car moving along a straight track at a constant speed. On the basis of application the developed stigmatic model allows evaluating the energy parameters of magneto-induction sensors depending on the properties of modern magnetic materials. The simulation results showed that the MMF value is constant the magnet determines the main parameters of magneto-induction sensors, so the use of modern magnets based on rare earth they allow to eliminate the traditional disadvantage of outdated types of magneto-induction sensors, that is, to reduce their size and weight. The application of the proposed stigmatic model expands the scope of possible solutions to extreme problems for selection and justification parameters of magneto-induction sensors, helps to improve the accuracy of systems for diagnosing the technical condition of the car fleet and traffic safety on railway transport.

The authors consider the question of the limits of applicability of the capacitor method for measuring the real part of the dielectric constant of printed circuit boards and telecommunications cabled rail transport using the example of FR-4 fiberglass laminate and the cable PK-75-4-12 in the frequency range from 10 Hz to 100 MHz. The measurements were carried out at a constant temperature and humidity of a known material. Comparison of the obtained values with the passport data on the material is carried out; a measurement procedure is developed with overlapping frequency ranges by changing the values of the measuring resistors from larger to smaller with increasing frequency of the input signal. It is shown that in the high-frequency region, the measurement accuracy is directly affected by the parasitic inductance of the capacitor sample under study, as well as the active resistance of the leads and plates and its increase due to the skin effect. The article also discusses the ways of accounting and calculating the parasitic elements of a capacitor. One of these ways is to study the characteristics of the elements of the sample at the first proper serial resonance of the capacitor under study.

The paper considers the use of simulation modeling in the reengineering of technological processes for repairing rolling stock units on the example of repairing a bogie model 18-578 of an open-top car. The most time-consuming sub-process of repairing the bolster of this bogie was considered as the object of reengineering. Three options for reengineering of this subprocess were considered, implying a complete replacement of the technological equipment currently in use at repair operations (positions) with more efficient positions of the subprocess. To substantiate the choice of the most preferable reengineering option, the values of such indicators of the functioning of the subprocess under consideration as its productivity per shift (throughput), the load factor of the resources used at the repair positions, the volume of work in progress at the end of the shift, the number of workers employed in production and the costs associated with the possible purchase of new technological equipment. Simulation modeling of the functioning of the considered sub-process of bogie bolster repair was carried out on the basis of the methods of the queuing theory. The construction of simulation models and their assessment of the above indicators were carried out in the Arena RockWell Software environment. When developing simulation models for each of the possible options for reengineering a subprocess, the discipline of its organization and maintenance was taken into account. In the article, for each of the reengineering options, the calculated quantitative estimates of the listed indicators are presented, obtained using the corresponding developed simulation models. The use of these assessments reduces the risks in the development and subsequent implementation of organizational and technical solutions associated with the modernization of the considered technological sub-process of repair of the bolster of a gondola car bogie.

Microminiaturization elements of communication systems contributed to development Internet of Things, which led the expansion of various railway transport services. One of the Internet of Things component`s is the wireless sensor network (WSN). Feature of WSN is a dynamically changing spatial and information network environment. It complicates the adoption of promptly reliable management decisions based on assessments of the states of network elements. One of the directions of making a reliable decision in a complex network environment on the WSN is using cognitive maps in the WSN control nodes. In this article discusses various models of cognitive maps for assessing the states of network elements and network processes, which can also be used for railway transport services.

Station radio communication is an integral part of the technical means involved in the organization of a safe transportation process. Increasing the signal power in places with a complex electromagnetic environment remains an urgent issue. A passive repeater can serve as a solution to this issue, therefore the purpose of this work is to test the possibility of increasing the signal power level using a passive repeater.The article provides an analysis of a passive repeater used as a device that improves the quality of radio communications in places with a difficult electromagnetic environment. The differences between the use of a passive repeater and active relay stations are given.An analysis of the existing methods for calculating the parameters of passive repeaters was carried out, on their basis, modeling and calculation of the parameters of a passive repeater were carried out for the development and conduct of research in real conditions at a railway station. The design, materials of manufacture of the passive repeater, as well as the measurement scheme in real conditions are presented.The study is based on theoretical calculations and performance checks in real conditions and comparison of the results obtained. As a result of the study, it was found that the use of a passive repeater in a complex electromagnetic environment makes it possible to increase the signal power level, thereby increasing the stability of radio communication.It was noted that it is necessary to refine the existing method for calculating a passive repeater, since the above technique was used when calculating passive repeaters over long distances. A variant of fastening passive repeaters without the development and installation of additional new structures is proposed, the need to organize further protection against overvoltage is indicated.The results obtained will be useful in the development of new radio relay communication lines and the modernization of existing ones for places with a difficult electromagnetic environment and rough terrain.

The influence of systematic failures to the functional safety of automated control systems of hazardous technological processes is considered. It is shown that stability ensuring of the process control system to systematic failures is an actual task for today. Approaches to increase the robustness to systematic failures recommended by IEC 61508 are presented. Special attention is paid to methods based on diversion. The functional diversity and technology diversity have been revealed in detail. Examples of using diversification in railway automation systems are given. The main problems of using diversification to increase resistance to systematic failures are formulated. The main advantages of using diversification are increased resistance to systematic failures and reduced risk of dangerous failures through the usage of diversified protection methods at the functional levels of the APCS. The disadvantages of using diversification are a significant increase in the costs of developing and automated process control system maintenance, the difficulty of confirming the different behavior of diversified channels in case of systematic failures, and the lack of an effective method to assessing the sufficiency of the obtained diversification for a given level of safety integrity.