Mathematical models of resonance and antiresonance processes

The use of the symbolic (complex) method has significantly simplified the study of resonance and near-resonance phenomena, in particular, it has made it possible to deeply unify and formalize the consideration of various mechanical systems. The cumbersome and time-consuming operations associated with composing and solving differential equations have been replaced by simple algebraic transformations. The method is based on the mechanical analogue of Ohm’s law in a complex representation and the concept of mechanical reactance, resistance, impedance, susseptance, conductance and admittance. Resonances and antiresonances of forces and velocities are determined. Resonances occur when the elements are connected in parallel with a force source, or when the elements are connected in series with a velocity source. Antiresonances occur when a parallel connection and a speed source are combined, or a serial connection and a force source are combined. These concepts are a generalization to mechanics of the concepts of «voltage source» and «current source» from theoretical electrical engineering. The closest to the source of speed in its properties is a crank-rocker (connecting rod) mechanism with a massive flywheel. The source of force corresponds more to the rod of the significantly smaller of the two connected pneumatic cylinders.

The place and role of analytical research of personnel training processes for the transport industry

The defining role of analytical research of personnel training processes for the transport industry is indicated. In particular, the possibility of using the vicious Knall’s circles to identify problems in the development of transport education is investigated. The traditional functionality of the Knall’s circles has been expanded to the study of the mechanisms of positive development of the research object. Two types of models for describing these processes are proposed and analyzed, taking into account both additive and multiplicative effects of development. Using concrete examples, the methodology for constructing various types of process models, selecting the optimal type of model and predicting development is shown. A systematic approach to the study of transport education is also proposed to be implemented using the tools of cenological analysis, which takes into account all participants in the personnel training system in the industry. The scientific and educational values of transport education allow us to determine the completeness and stability of the educational system, the direction of development (degradation, positive development of the system), the role and place of an individual educational institution in the personnel training system. The cytological study is illustrated by the example of the analysis of the results of the activities of branch railway universities. Scientific and educational self-regulating organizations for training specialists for the regional transport system are considered as one of the mechanisms for managing transport education. It is proposed to create self-regulating organizations of personnel training that regulate the activities of educational institutions, both among themselves and with consumers of educational services.

Lightning protection of the object located on the slope

The article points out the drawback of all the current instructions for the lightning protection device: the lack of instructions for calculating the lightning protection zones of an object located on a slope. The methods of applying the current instructions for the lightning protection device when placing an object on a slope are given, based on the assumption that lightning strikes the lightning rods vertically and perpendicular to the slope. The features of the choice of lightning protection characteristics (calculated points of the protected object, calculated heights of lightning rods, methods of constructing lightning protection zones) are described. A method for calculating the lightning protection zones of an object located on a slope is proposed, based on the assumption that lightning strikes lightning rods perpendicular to the slope, in particular, the concept of the axis of a conditional lightning rod shifted on the object plan for calculating lightning protection zones is introduced. The consequences of the application in engineering practice of the methodology for calculating the lightning protection zones of an object located on a slope, based on the assumption that lightning strikes the lightning rods perpendicular to the slope, are indicated. Using a pulse voltage generator, tests were performed on a model of a lightning rod located on a slope in order to determine the direction of lightning strikes-vertical or perpendicular to the slope. It was determined experimentally that the proposed method for calculating the lightning protection zones of an object located on a slope, based on the assumption that lightning strikes lightning rods perpendicular to the slope, should be used in cases where the protected objects are located on slopes with an angle of more than 25°.

Calculation of tonal rail circuits with consideration of a complicated waveform

The article deals with the problem of calculating modern audio frequency track circuits, the working signal of which is a frequency-manipulated signal transmitting Bauer codes. Such signals have a wide spectrum, which leads to the error in the calculations performed according to the classical method for a single frequency. Increasing the code transfer rate in order to reduce the response time of track circuits further expands the signal spectrum, which negatively affects the safety of such rail circuits. To determine the width and composition of the signal spectrum, a discrete Fourier transformation is used. The new method of calculating rail circuits proposed in this article allows us to determine the root-mean-square value of the signal at the output of the rail circuit with a known amplitude-frequency characteristic of the rail circuit and the form of a complex signal at the input. The obtained ratio of the root-mean-square signal levels at the input and output of the rail circuit allows us to solve the problem of calculating the operating modes of the rail circuit taking into account its nonlinear amplitude-frequency characteristics and taking into account the complex signal form, including consideration of the specific transmitted Bauer code. This solution allows you to increase the reliability of the calculation of the adjustment tables of the tonal track circuits and, as a result, increase the reliability and safety of their operation.

Investigation of the causes of damage to freight cars during disbanding on non-mechanized sorting slides and development of measures to prevent them

The damage assessment of freight cars during shunting and loading and unloading operations was made. The need to review the normative documents regulating the relationship between the owners of rolling stock, owners of non-public tracks and the carrier is noted. The reasons for formation of damage on the wheel pairs of freight cars when disbanding on low-power sorting slides are considered. The conditions for ensuring the deceleration of detachments on non-mechanized sorting slides without damaging the wheels are determined. The analysis of methods for ensuring braking on low-power slides is carried out. A method was chosen to ensure the wheel set rotation by introducing a third body between the rubbing surfaces during the braking of cars, which will take over a part of the resulting heat flow, reducing the temperature and increasing the coefficient of friction in the «wheel-rail» contact zone. A method is proposed to provide braking on the non-mechanized sorting slide during shoe braking by applying a friction compound to a non-working rail. Laboratory tests were carried out, which showed that the introduction of a friction additive can achieve the necessary coefficient of friction to comply with the standard parameters of deceleration of the car in the braking zone.

Intersectoral information and intellectual model of integration of information flows of interregional level subjects

Modern challenges actualize the search for transformation of management and interaction mechanisms and tools for determining and making optimal managerial decisions based on quota (distributed) information and intellectual content, which create conditions for the implementation of a systematic method for solving the problem of creating a large-scale and multifunctional complex of information and intellectual management and interaction systems. In this paper, the principles of building an intersectoral information and intellectual model of integration of information flows of subjects of the interregional level are considered. The construction of the model is based on the principles of information and intellectual interaction in the segment of the information economy of social and marketing cooperation. The components of the model formation methodology are presented. The system of component-methodology assumes concentration in one perimeter of information flows coming from the integrating information systems of subjects of the intersectoral, interregional level, federal regulators and business associations, using the information technology «big data». The model of integration of information flows accumulates and concentrates information knowledge in a single transport and information space and is a quota-based information and intellectual system, the structure of which reflects the coordinated interactions of virtual agents. The subjects of accumulation and concentration of information knowledge are virtual agents (integrating information and intellectual systems) of regulators, subjects and business associations. The creation of such virtual agents is based on the multiagent construction principle. Virtual agents are a new category of software products that operate in information and intellectual environment on behalf of the user. The principles of virtual agent modeling and methodology for constructing the model were used in creating software products «Electronic Service of integrated transport services» and «Multiagent intellectual system for management of transport services in rail-marine traffic», which were registered by the state.

Forecasting and verification of railway transport energy efficiency key indicators

The article reflects the issues of forecasting the target indicators of energy efficiency on the example of JSC «Russian Railways». The approaches selected for assessing the quantitative values of the key performance indicators of the Russian Railways holding in the development of the Energy Strategy for the period up to 2020 and for the future up to 2030 are considered. The accepted methods are conventionally classified into four groups, including: a heuristic method based on the analysis of time trends, an indirect method based on known values of indicators and using mathematical models. The method of forecasting the specific consumption of electricity and diesel fuel for train traction and the energy intensity of the production activity of JSC «Russian Railways» is considered in detail. Regression models have been developed that characterize the dependence of the specific fuel and energy consumption on such indicators as the volume of transportation work, the average mass of the train, and the share of freight work in the total work. In order to assess the accuracy of the obtained forecast values of the indicators included in the energy strategy of JSC «Russian Railways», they were verified by the results of 2017-2019. The results obtained allow us to speak about the sufficient effectiveness of the approaches considered in the article to predict the KPI of JSC «Russian Railways». The error in forecasting the main indicator of energy efficiency of JSC «Russian Railways» - the energy intensity of production activities - was 0,06 %.

The laws of distribution of some parameters when organizing the movement of trains

The article discusses the key factors for the organization of train traffic. The analysis of statistical parameters of the intervals of departure of freight trains from railway stations and the length of the freight train flow is carried out. Based on these train schedules, graphical dependences of the intervals of departure of trains from separate points on the volume of train traffic and the distribution of train lengths in even and odd directions are constructed. Polynomial dependencies with coefficients of variation are derived. The curve of the second-order Erlang distribution function for the departure intervals is constructed. It is determined that the average departure intensity in one hour is equal to three trains, and the average departure interval lies between the 25th and 35th minutes with a probability of 0.793. There is a correlation between the coefficient of variation (mean square deviation) of the departure interval and its average daily deviation. The power function of the analytical ratio of the coefficient of variation from the average interval of departure of freight trains from the technical stations of the Krasnoyarsk railway during the day is determined using the least squares method. The degrees of correspondence of theoretical and statistical distributions of the number of cars in trains are studied using the Kolmogorov criterion with the calculation of the probability value and confirmation that the distribution of the number of cars in trains obeys the binomial law. Using the Pearson agreement criterion, it is proved that the frequency of departure of freight trains from railway stations obeys the exponential distribution law.

Approaches to assessing the impact of transformation of professional competencies of the staff on the energy efficiency of railway transport enterprises

The article deals with the impact of transformation of professional competencies on energy efficiency of the structural divisions of railway transport. The analysis of existing trends in the development of professional competencies in the field of energy saving and energy efficiency improvement in the context of active digital transformation is carried out, as a result of which the authors focus on additional professional education. Approaches to the quantitative and qualitative assessment of the impact of competence transformation on energy efficiency are considered, including historical and external benchmarking, as well as cluster analysis, and their advantages and disadvantages are described. An enlarged algorithm for evaluating the energy efficiency of enterprises is formed, taking into account the transformation of competencies. As initial data, the authors consider the energy efficiency indicators of structural divisions in relation to production and climate factors and the results of a survey of specialists. It is concluded that it is necessary to apply a comprehensive approach to assessing the transformation of competencies, which will effectively solve management tasks in this area, depending on the specifics of economic activity of a structural unit, the relative level of its energy intensity and other technological and socio-economic conditions.

Assessment of feasibility of placing the parking space of passenger cars on the basis of simulation modeling

The article deals with the issues of assessing the development of parking systems of passenger cars in large cities based on the use of the simulation modeling method. With the help of AnyLogic software, a simulation model for evaluating the feasibility of parking space placement has been developed. The proposed simulation model simulates the movement of vehicles on a section of the road network (RN) and determines the number of cars that could not park due to the lack of parking spaces. Three calculators are built into the simulation model. The first calculator calculates the required number of parking spaces based on standard values, depending on the purpose of the object near which the parking space is planned. The second calculator allows you to determine the preliminary cost of the project, depending on the type of parking space. The third calculator evaluates the efficiency of the project, changes such indicators as the required number of cars, the average time spent by cars in the system under study, their average speed, the number of car stops. Using the developed model allows you to determine changes in the values of traffic flow indicators and choose the optimal type of parking space, based on a preliminary assessment of the expected economic effect.