Wagon Operation Research Articles

A new multi-modal time series transformation method and multi-scale convolutional attention network for railway wagon bearing fault diagnosis

To align with the evolving trends in intelligent railway wagon operation and maintenance and to enhance the precision of railway wagon bearing fault diagnosis, this paper introduces a novel method for bearing fault diagnosis. The method comprises two key innovations. Firstly, a multi-modal time series transformation method is proposed. This method extracts time series data from the original time domain signals via self-adaptive ensemble empirical mode decomposition with adaptive noise, transforms them into 2D matrices, and captures inter- and intra-period information relationships through convolution. Secondly, a multi-scale convolutional attention network is introduced, enriching fault information by utilizing parallel multi-scale convolution for down-sampling. To prevent feature loss, sliding convolution is adopted instead of pooling. Additionally, the model incorporates the convolutional block attention module to focus on critical information. Experimental validation conducted in a laboratory using a self-developed railway wagon bearing dynamic performance tester demonstrates high diagnostic accuracy and strong overall performance. The method’s generalizability is further confirmed through validation using publicly available datasets. This method could find practical use in railway maintenance, improving the accuracy of bearing fault diagnosis, and making operations more efficient.

Optimization of Volume for an Automatic Feed Wagon by Graph Theory Based Modeling

Within the project of developing an automatic feed wagon, the initial task is to determine its overall parameters, which directly depend on the wagon volume. (Research purpose) To simulate the automatic feed wagon operation in order to determine the optimal volume ensuring the versatility of its use in cattle cowsheds accommodating different numbers of animals, and practicing different feeding frequency. (Materials and methods) The solution to the problem is based on the calculation of the feeding time taken by the automatic feed wagon. The time must not exceed the limit values established by zootechnical standards. To calculate the feeding time taken by an automatic feed wagon, a graph-theory-based simulation method was used, taking into account the probabilistic nature of the components of feed mixture distribution time balance. The calculations were performed in MS Excel. (Results and discussion) The paper describes the conditions for simulation and considers two options for the automatic feed wagon operation, in particular the option when one robot serves two cowsheds and the other when each cowshed is served by a separate feed wagon. (Conclusions) The second option with a separate automated feed wagon for each cowshed is proved to be more suitable. It has been obtained that in this case, the reduced movement length results in a 27.9-36.2 percent increase in productivity of the automatic feed wagon; besides there is no need to install automatic gates and build an insulated vestibule to move the robot between the cowsheds. Thus, the programming task becomes simplified. It has been found out that an automatic feed wagon having the volume of 2 cubic meters is enough to feed animals in the cowsheds sized 111.9 meters by 26.6 meters and smaller, accommodating up to 340 cows, and with a feeding frequency of 4-8 times a day.

Detection and Recognition of Tilted Characters on Railroad Wagon Wheelsets Based on Deep Learning.

The quality of railroad wheelsets is an important guarantee for the safe operation of wagons, and mastering the production information of wheelsets plays a vital role in vehicle scheduling and railroad transportation safety. However, when using objection detection methods to detect the production information of wheelsets, there are situations that affect detection such as character tilting and unfixed position. Therefore, this paper proposes a deep learning-based method for accurately detecting and recognizing tilted character information on railroad wagon wheelsets. It covers three parts. Firstly, we construct a tilted character detection network based on Faster RCNN for generating a wheelset's character candidate regions. Secondly, we design a tilted character correction network to classify and correct the orientation of flipped characters. Finally, a character recognition network is constructed based on convolutional recurrent neural network (CRNN) to realize the task of recognizing a wheelset's characters. The result shows that the method can quickly and effectively detect and identify the information of tilted characters on wheelsets in images.

Emission of Structural Noise of Tank Wagons Due to Induced Vibrations during Wagon Operation

Railway transport is considered relatively environmentally friendly in terms of energy consumption and air pollution, but it is relatively unfriendly in terms of noise pollution. Noise and vibrations propagating to railroad surrounding areas are disturbing populations. In order to minimize this noise, legislation and regulations such as TSI NOI have been adopted and research of noise and vibrations generated by railway transport has been carried out. Such research has been carried out also by our team focused on experimental investigation of noise generated by railway wagons, in this particular case on tank wagons. We simulated the structural eigenfrequencies of both bogies and tanks using FEM models to find vibrations and corresponding noise levels generated by these vibrations. Theoretical results have been compared with results of measurements of noise generated by impact hammer and visualization of noise fields using a digital acoustic camera Soundcam. Based on the simulation and measurements, principal frequency noise domains of fundamental noise sources were determined—rolling (40–63 Hz), tank (200–1000 Hz), bogie (400–1600 Hz), and wheel (800–10,000 Hz). Measurements on the railway line under real operational conditions at two train speeds have been carried out, too, to see the actual external noise levels.

Теміржол көлігі кәсіпорындарының қоршаған ортаға әсерін экологиялық-экономикалық талдау: («Қазақстан темір жолы» ҰК »АҚ филиалы-«Магистральдық желі дирекциясы мысалында)

The impact of rail transport on the environment is one of the major problems in the Republic of Kazakhstan. It is well known that railway transport causes enormous harm to the environment, destroying natural relief during the construction of railways, pollution of water and air objects also creates physical pollution for people, and the operation of wagons and the transport of hazardous substances can lead to a high degree of pollution and land degradation. This study was aimed at identifying the ecological and economic problems of railway transport in the territory of the Republic of Kazakhstan. For the analysis, materials and data on environmental protection were collected. The results showed that reducing the impact on the environment was achieved through measures of environmental legislation. This concerned the reduction of the use of liquid and solid fuels, the equipping of emission sources with the necessary purification equipment, the reconstruction of environmental protection facilities, and the development of regulatory and environmental documentation. Based on this, it is shown that the use of environmental technologies for practical purposes can ensure the effective functioning and operation of a natural resource user enterprise from an environmental and economic point of view.

Strength and life estimation for assigning the useful life of wheelpairs of high-speed flat wagons

Aim. The most vital unit of railway rolling stock is a wheelpair, as a broken wheel or axle may have catastrophic consequences. Therefore, before the production of a highspeed flat wagon designed for operation at speeds of up to 140 km/h, which is unique for the 1520 mm gauge space, could commence, it was required to research the applicability of the standard wheelpair for high-speed movement. Ensuring the safe operation of a wheelpair involves compliance with the requirements that are to be confirmed by means of assessment of strength and durability parameters [1]. Product conformity assessment may be based on the requirements of standards, whose voluntary fulfilment ensures compliance with [1], or other documents. Methods. The paper describes the computational and experimental methods used for confirming the strength and estimating the life (durability) of wheelpair elements in the probabilistic setting. As experimental data, the authors used the results of full-scale bench testing of wheelpairs for fatigue using the method of rotational bending as it best approximates the loading conditions in operation. The results confirmed the endurance limits of the axle and wheel as parts of an assembled wheelpair. Using design analysis, the authors examined the stress-strain state of the wheelpair caused by installation and operational loads in various running modes. Results. The conducted studies confirmed the wheelpair’s compliance with the requirements of [1–3] in terms of safety factors of fatigue strength and endurance, which eliminates the possibility of hazardous situations in the course of high-speed flat wagon operation. The time to fatigue crack nucleation in wheelpair components was evaluated using the fatigue resistance figures of the parts and equivalent amplitudes of dynamic stress caused by operational loads. It appears that this assessment allows establishing – with the assumed probability of destruction – the assigned useful life of a wheelpair axle at 32 years, which corresponds to the assigned useful life of the flat wagon according to the combined criterion. Corresponding standards and regulations required for developing the container-carrying flat wagon are being updated and a new State Standard is being developed. Conclusion. The conducted conformity assessment established that the flat wagon wheelpair meets the safety requirements of [1] and ensures the absence of unacceptable risks associated with harm to life and health of people, animals and plants, the environment and property of individuals and companies in the course of flat wagon operation.

Forming an automated technology to manage freight transportation along a direction

The study investigated the process of rolling stock movement along a direction and took into consideration possible risks during transportation of freight. It revealed the main reasons, which cause effects of the first and last mile. They include, namely, the lack of the required number of technically sound rolling stock on scheduled time and significant difficulties with the passage of trains, specifically through port and border stations. The study formalized the technological process of transportation of freight along a direction in the form of an optimization mathematical model of the process of movement of freight wagons. The objective function of the model represented total operation costs. Its basis was the Lebesgue-Stieltjes integral, which took into consideration the effect of the first and last mile. The model also took into consideration possible risks, which arise in the process of wagon operation. It is expedient to refer the built optimization model to the problems of stochastic programming. The analysis of statistical data showed that the time required for wagons to move from an initial station of a route to a port station and the time required for movement of wagons from a port station directly to a port conform to normal distribution. The presence of a positive correlation between these two values gave reason to consider the corresponding parameters within a single probabilistic field. This approach made possible to determine probability of untimely arrival of wagons to a port more accurately and, accordingly, to determine a value of financial risk. The modeling proved that there was an extremum of the objective function of the minimum type, which made possible to form a procedure for optimal control of transport parameters. Thus, the generated model is universal in nature. It gives possibility to manage the transportation process with the lowest operational costs for the railway in the presence of feedback. Calculations showed a decrease in railway costs approximately by 10 % comparing with the costs calculated according to the existing method of determination of the actual cost of transportation of freight. The optimization model is the basis for formation of an automated technology for the management of freight traffic. We propose to implement it in the form of a system of decision support for the dispatcher staff

Development of an algorithm for investigation of technical state of wagons’ running gears during their derailment

A freight wagon is a collection of a large number of parts and assemblies that form a single structure. During wagon operation, there are gradual changes in the characteristics and parameters of its structural elements. That is, the parameters of its constituent elements change – their numerical values increase or decrease that result in a change of the unit’s technical state, and, in turn, affects the totality of its performance. Gradually accumulating, the changes in the parameters of the structural elements of a wagon reach such a level that radical, sometimes abrupt qualitative change occurs. A malfunction that has not been repaired timely may lead to a failure of a wagon structural element, which, in turn, may result in rolling stock derailment. It has been established that the loss of stability of freight wagons during their movement is most often due to their unsatisfactory dynamic properties, which can be explained by design features and technical state of running gears. In this regard, the authors of the article have developed an algorithm for investigation technical state of running gears of freight wagons and determined the effect of their parameters’ deviation on rolling stock operation with possible further derailment.

The efficiency of condenser energy-storage systems for underground wagons

A procedure for determining the efficiency of condenser energy-storage systems that are installed in underground cars for receiving electric power for traction electric cars working in a recuperative-braking regime is proposed. It was suggested to carry out comparative analysis of the efficiency of energy-storage systems on the basis of the following parameters: index of electric-power recovery in a full start-brake cycle of the wagon operation, relative determination of electric-power recovery in the braking regime and electric-power loss in the active regime of car operation, index of electric-power recovery in electrodynamic braking of traction electric cars, and relative evaluation of the mass of energy-storage systems. It is proposed to analyze the efficiency of energy-storage systems taking into account their design features. Energy-storage systems can be manufactured in a monoblock or stepped design. The proposed procedure of comparative analysis of the energy and mass-dimensional characteristics of underground cars with energy-storage systems allow their operation to be evaluated with a minimum number of source data. Installation of energy-storage systems increases the mass and energy expenditure during wagon operation, but this loss is significantly less than the energy volume recovered with an energy-storage system in a regime of recuperative braking of traction electric cars. Energy-storage systems allow one to create effective systems of autonomic recuperative braking on underground cars. A stepped design of energy-storage systems decreases their mass-dimensional characteristics and increases energy efficiency. The only real disadvantage of energy-storage systems preventing their use is their large size.

Аналіз відомих пристроїв закріплення составів і загородження колій у сортувальних парках

У статті проведено докладний аналіз відомих пристроїв закріплення составів та загородження колій у сортувальних парках залізничних станцій. Зроблено висновок, що в існуючому вигляді жоден з розглянутих пристроїв не може бути використаний на вітчизняних залізницях без додаткового доопрацювання, проте доцільність їх застосування на мережі залізниць України є беззаперечною.

THE IMPROVEMENT OF THE COMPENSATION PROCEDURE IN MONETARY FORM FOR LOST OR DAMAGED FREIGHT WAGONS OF OTHER STATES

It is found that the cost of lost (damaged) wagons determined in accordance with the operating order of indemnity of losses differs considerably from the market cost. This difference is related to a discrepancy of normativeprices on new wagons to the prices of manufacturers as well as to a gap of used method of account of wagon deteriorationto the relation between the cost and the time of wagon operation, which is at the market. At the choice ofmoney form of indemnity of losses, it is suggested to determine the wagon cost by independent (expert) estimate or the set norms at the discretion of railway administration-owner. In so doing, to change the method of determinationof wagon deterioration from a rectilinear one on a method of decreasing rest. In addition, the periodic update ofnormative prices on new wagons should be provided.