Locomotive Operation Research Articles

To the question of ventilation of underground mine workings during operation of diesel-hydraulic locomotives

To the question of ventilation of underground mine workings during operation of diesel-hydraulic locomotives

Characteristics and GWO–ANN Model Based on Prior Knowledge for Contact Resistance in a Pantograph–Catenary

The current-collection performance of a pantograph–catenary directly influences the safe operation of high-speed electric locomotives. The contact resistance is a primary indicator to evaluate the stability and reliability of the current-collection performance. The effects of sliding speed and electric current on the contact resistance between the carbon strip and the contact wire under a dynamic pressure load were studied using a sliding electrical contact testing machine. To predict the contact resistance under various working conditions, an artificial neural network (ANN) regression model, based on the gray wolf optimizer (GWO) algorithm and prior knowledge, was developed. The GWO algorithm was used to optimize the initial biases and weights of the ANN to avoid becoming trapped in local optima. The performance of the GWO–ANN can be further enhanced by the use of prior knowledge. The results showed that the GWO–ANN model that included prior knowledge can be introduced as a new technique for estimating the contact resistance in pantograph–catenary systems.

Development of the system of coordinated control of traction power supply equipment and electric rolling stock

The aim of the study is to develop a system of coordinated control of traction power supply equipment and electric rolling stock based on self-organization principles. The research methods of the study are based on multi-agent approach and include coordination of settings of static equipment of reactive power compensation, on-load tap changing of traction transformers, other voltage regulators in the contact network, microprocessor protections, modes of operation of electric locomotives in the interstation area. The obtained results made it possible to substantiate the model of self-organizing control system of traction power supply equipment and electric rolling stock, including the description of interaction and coordination principles, attributes, ontology, algorithms of the efficiency of local regulators of traction network and electric locomotives. The study presents the description of the information model of the traction power supply system and electric rolling stock to control modes and increase the throughput capacity of the power supply system by means of optimum allocation of traction resources. The results of the simulation modeling have confirmed the effectiveness of the proposed solutions.

Detection of Locomotive Signal Lights and Pedestrians on Railway Tracks Using Improved YOLOv4

Intelligent detection of locomotive signal lights and pedestrians on railway tracks is of great significance to the safe operation of locomotives, especially under bad illumination conditions. Due to the highly complicated operation environment of railway locomotives, it is relatively difficult to apply deep neural network-based object detection methods in the recognition of locomotive signal lights and railway pedestrians. This work, for the first time, proposes a real-time detection method based on improved YOLOv4 to recognize locomotive signal lights and railway pedestrians. In our method, the Region-of-Interest is introduced into the original network of YOLOv4 to improve the detection precision of pedestrians on railway tracks. Importantly, we establish a dataset called detection of locomotive signal lights and railway pedestrians (DLSLRP), which is dedicated to the training, testing, and validation of related convolutional neural networks. We evaluated the proposed detector on DLSLRP dataset, the experimental results suggest that our method can detect locomotive signal lights and railway pedestrians with high speed and accuracy under different illumination conditions. The mAP reaches 93.52%, and the detection speed achieves 25 FPS.

Methods for rationing the risk of violations in the quality of operational work in railway transport

In a competitive transport market, the effective organization of the entire transportation process and operational work carried out at railway stations and junctions is an important and urgent task for improving the quality of the use of rolling stock involved in the transportation of goods. The paper uses the theoretical and methodological foundations of the modern concept of analysis and assessment of the operational work quality. Methods for identifying factors of violation of the normal course of the transportation process are shown, and an assessment of economic losses arising from the risk of its violation is given. A feature of the paper is the application of methodological approaches to identifying risk factors for all participants in transportation - structural divisions, related not only to the traffic service and freight facilities, but also to the locomotive and carriage facilities, track facilities. The results of the study allow developing risk management mechanisms not only in the technology and organization of the work of railway stations, but also in violations of the production processes of other performers: locomotive operating depots, car operating depots, track maintenance departments.

Design of Monitoring System for Brake Shoe of Electric Locomotive

With the improvement of railway running speed, the safe running of locomotive and rolling stock is particularly important. At present, China has built a series of world-leading high-speed railways with speeds of 350Km/h. With the increase of high-speed train running speed and actual traction capacity, higher requirements for high-speed railway operation safety are put forward. Braking is a very important problem for electric locomotive whether it is in the process of high speed or heavy load. At present, the braking devices of electric locomotives are mainly cast iron brake shoes, which are made of cast iron or other materials to produce braking force through the mechanical friction between the brake shoes and the wheel tread. However, there is no detection of brake working condition in the online detection of electric locomotive operation. This paper analyzes the technical research status of brake shoe of electric locomotive, and analyzes the shortcomings of existing technology. Based on the current technical background, a monitoring system for brake shoe of electric locomotive is designed, which provides a firm foundation for reliable braking of electric locomotive.

ОПРЕДЕЛЕНИЕ ПАРАМЕТРОВ ПОЕЗДА В ПУТИ СЛЕДОВАНИЯ ПО ДАННЫМ БОРТОВЫХ ИЗМЕРИТЕЛЬНЫХ СИСТЕМ ГРУЗОВЫХ ЭЛЕКТРОВОЗОВ

The paper suggests an approach to determination of actual train operation parameters according to data from on-board measurement systems in order to increase efficiency of application of automatic electric motive power operation systems. The authors have analysed scientific works in the sphere of improvement of automatic electric locomotive operation. The paper also presents results of comparison of grade computations in KORTES and real data from on-board measurement systems on 2ES6 electric locomotives that operate on a section of the West-Siberian Railway. As a result, the authors have substantiated a possibility to apply data gained from on-board measurement systems in real-time mode for determination of such train parameters as tractive effort torque of traction motors, electric locomotive traction effort, external forces of train tractive resistance, reduced gross load hauled and etc. The approach to determination of train parameters according to data of current measurements allows increasing peculiarity of transmission of control actions and efficiency of an automatic train operation system.

СИСТЕМА УПРАВЛЕНИЯ СИЛОВОЙ УСТАНОВКОЙ МАНЕВРОВОГО ТЕПЛОВОЗА С АЛГОРИТМОМ АВТОМАТИЧЕСКОГО РЕГУЛИРОВАНИЯ СКОРОСТИ

Work objective is to develop an algorithm for automatic speed regulation and to ensure its integration into the system of adaptive combined control of the power equipment of the locomotive TEM7A. Research methods: methods of the theory of automatic control, modern programming methods, trial trips. Research results and novelty. For the first time, the problem of automatic maintenance of "creeping" train speeds with high accuracy has been solved in the practice of domestic locomotive construction. It is established that the developed algorithm for automatic control of the humping speed and splitting up of shunting locomotive TEM7A allows maintaining a given speed in the range of operating speeds up to 8 km / h. Conclusion. The developed algorithm is integrated into the microprocessor control system of the power equipment of TEM7A shunting locomotive and does not require additional costs when through the locomotive operation. Maintaining a uniform speed of movement can also be used in the mode of manual control of the locomotive by the driver, while the value of the stipulated rate is set by the driver using the display module of the control panel.

CHOICE OF LOCOMOTIVE PARK MAINTENANCE STRATEGY WHEN INTRODUCING THE SERVICE

In operation, sometimes there are situations of uncertainty in assessing the technical condition of locomotive equipment and at the same time choosing the optimal strategy for its maintenance, including the possibility of using the service. Application of the concept of service gives the chance to stimulate work of all divisions of locomotive economy, to save all kinds of resources for operation of locomotives. According to this, the article substantiates the choice of strategy for maintaining the locomotive fleet using the provisions of the theory of statistical solutions. Game theory approaches were used to theoretically substantiate the transition to a service for decision-making in conflict situations and to determine the optimal strategy of behavior of each of the participants in this situation. Approaches to the choice of strategy for the maintenance of the locomotive fleet during the introduction of the service on the basis of the provisions of the theory of strategic games on the criterion of maximum efficiency were considered. It is shown on examples of the decision of some problems of a choice of maintenance strategy of locomotives for various industrial situations. It is concluded that a mixed strategy describes different situations best and allows to made rational decisions. It is also noted that the most effective approach to concretize the algorithm of actions is the complex application of the theory of strategic decisions, the theory of fuzzy sets, the theory of pattern recognition.

Risk Assessment for Electrified Railway Catenary System Under Comprehensive Influence of Geographical and Meteorological Factors

Catenary is essential for electric locomotives to obtain electric energy, and it is crucial to the normal and stable operation of electric locomotives. However, the catenary is completely exposed outdoors without backup equipment. Therefore, compared with other power supply equipment in traction substation, catenary is more likely to be affected by external geographical and meteorological factors. In order to comprehensively assess the probability and consequence of catenary failures under the impact of external geographical and meteorological factors, a risk assessment method for electrified railway catenary is proposed in this article. First, the influence of external geographical and meteorological factors on catenary failures is analyzed based on the actual operation records. Then, considering the high efficiency and service characteristics of railway transportation, the risk consequence indicators are established, and the cumulative risk of catenary failure is quantitatively evaluated. Based on this, the risk classification method is proposed, and the risk level of catenary is visualized with geographic information system (GIS) technology. Finally, the risk contribution indicator is proposed to describe the influence of catenary component on the total risk of catenary failures. The catenary failure records of Beijing–Shanghai Railway within the administration of Shanghai Railway Bureau in 2017 are used for a study case. The results show that the proposed method can comprehensively quantify and visualize the risk of catenary failures. Also, the critical components of the catenary system can be identified, which can provide effective information for the maintenance decision-making process.

ANALYSIS OF THE PROCESSES OF OCCURRENCE OF SUBHARMONIC COMPONENTS IN CONTACT POWER SUPPLY NETWORKS WITH NONLINEAR LOADS

The article considers the calculation of the modes of occurrence of subharmonic components in traction power supply networks of railway transport, containing traction converters, controlled and uncontrolled rectifiers. The processes of the appearance of harmonic components during the operation of electric locomotives with zone-phase and pulse control using a four-quadrant 4q-S converter in power circuits are considered. Harmonics related to the fundamental and subharmonic components are determined by the harmonic balance method.

INTELLIGENT HEALTH STATUS DETECTION METHOD FOR LOCOMOTIVE FUEL CELL BASED ON DATA-DRIVEN TECHNIQUES

Main drawbacks of fuel cell systems, namely, high cost, poor reliability, and short lifespan, limit the large-scale commercial application of fuel cell systems. The health status detection of fuel cell systems for locomotives is of great significance to the safe and stable operation of locomotives. To identify the failure modes of the fuel cell system accurately and quickly, this study proposed an intelligent health status detection method for locomotive fuel cells based on data-driven techniques. In this study, the actual test data of a 150-kW fuel cell system for locomotives was analyzed. The t-distributed stochastic neighbor embedding (t-SNE) algorithm was combined with the general regression neural network (GRNN) to intelligently detect the health status of the fuel cell system for locomotives. Specifically, t-SNE was used to process the high-dimensionality and strong coupling raw data of health status, enabling the dimensional reduction of the raw data to reflect essential features. Then, GRNN was used to identify the feature data to achieve the fast and accurate detection of the health status of the fuel cell system. Results show that the proposed method can effectively detect four health conditions, namely, normal state, high inlet coolant temperature, low air pressure, and low spray pump pressure, with a diagnostic accuracy of 98.75%. This study is applicable to the analysis of the actual measurement data of high-power level fuel cell systems and provides a reference for the health status detection of fuel cell systems for locomotives. Keywords: fuel cell system for locomotive; data-driven; general regression neural network; t-distributed stochastic neighbor embedding; health status detection

THE CONCEPT OF EXTENDING THE TERMS OF LOCOMOTIVE OPERATION

Due to the reliability standard set during the design and even when it reaches orexceeds the standard service life of more than 90 % of locomotives, railway transport continues toperform its functions. Many years of experience in the operation of locomotives confirm thecorrectness of the norms laid down in the standards for their design to the design loads andindicators of dynamics and strength of load-bearing structures: the standard stock ratio (2) ensurestheir operation during the service life.(25 ... 30 years) In many countries, as part of the extension of the service life of TRS at onetime had to solve complex scientific and applied problems. For example, most recently in Europeancountries, rolling stock depreciation was up to 65% of service life. In the interaction of TRSproducers and users, the concept of repair and modernization of TRS at the facilities ofmanufacturers was adopted, and the amount of modernization depended on customer requirements.After the modernization of the extension of the service life of TRS, it could be used on certainsections of the railway or in other types of work: economic, export, shunting. In our country, thelong-term operation of the TRS of a small number of series led to the fact that the rolling stock wasalmost not renewed and the problem of extending the service life was not solved. Now difficultpolitical and environmental factors have led to the fact that after some time it will be dangerous touse rail transport. As the world and domestic experience of TRS operation shows, urgent changes inall links of the industry and operation are necessary. The resource of TRS put in production allowsto keep and maneuver in a choice of strategy of management of the maintenance of TRS. Inconnection with the aging of rolling stock and the development of the assigned service life arerelevant to the study of the original and residual resources of the structure. To do this, thestandards must be clarified and supplemented on the basis of accumulated operating experienceand taking into account modern knowledge to assess and ensure the necessary durability and safetyof operation of vehicles. Based on this, the topic of changing the system of extending the service lifeis relevant. The article considers the concept of general approaches to extending the service life oflocomotives.

Automated system for warming up traction electrical equipment of an electric locomotive

The successful operation of electric locomotives depends largely on the reliability of electrical machines. Reliability is the most important technical and economic indicator of the quality of the functioning of any technical device, in particular an electrical machine, which determines its ability to operate without fail with unchanged technical characteristics for a given period of time under certain operating conditions. In the presented scientific work, a detailed analysis of the causes of breakdown of traction electric motors is made. The aim of the study is to develop a technical solution to reduce the heating time, power consumption and to exclude or minimize the formation of condensation on the insulation of traction motors. The expediency of modernizing the positions of locomotive warming up before calling for repairs has been substantiated. This technical solution meets all the requirements for maintaining traction electrical equipment in good condition. The found technical solution is aimed at increasing the operational reliability of the insulation of traction electrical equipment, reducing the time of the heating process.

ANALYSIS OF THE PROCESSES OF OCCURRENCE OF SUBHARMONIC COMPONENTS IN CONTACT POWER SUPPLY NETWORKS WITH NONLINEAR LOADS

In the article considers the calculation of the modes of occurrence of subharmonic components in traction power supply networks of railway transport, containing traction converters, controlled and uncontrolled rectifiers. The processes of the occurrence of harmonic components during the operation of electric locomotives with zone-phase and pulse control using a four-quadrant 4q-S converter in power circuits are considered, harmonics related to the main and subharmonic components are determined by the harmonic balance method.

The development of a representative multidimensional transient duty cycle for in-service switcher locomotives

Switcher locomotives operate in railway yards where they shunt railcars and assemble trains. Shunting railcars requires frequent aggressive acceleration and deceleration events in order for the locomotive to push or pull railcars onto specific tracks. As a result, switcher locomotives rarely sustain tractive power for any significant period of time. Given that all switchers in North America rely on diesel-electric propulsion; the result is rapid and frequent transitions in engine power leading to a very low engine efficiency and high levels of emissions. Any attempt to quantify or remedy these issues will face a lack of a representative profile or test cycle. A locomotive duty cycle is a breakdown of time spent at each power level of the locomotive’s engine. A major drawback of current duty cycles is that they only account for steady power. Such cycles are not representative of real switcher locomotive operation. This paper presents a real-world transient duty cycle for switcher locomotives that accounts for the rapid power transitions and is argued to be more statistically representative of actual operations. The methodology adopted relies on real-time data collection, microtrip based trip segmentation, and a finite mixture model-based clustering algorithm. Measurements were collected on a EMD 16-645 GP9 locomotive. The duty cycle developed herein is representative of switching operations in Southern Railway of British Columbia’s New Westminster Yard as an example of the methodology which can be repeated in other cases as well.

Relationship between particle and metal concentrations in subway workers’ personal breath zone (PBZ), exhaled breath condensate (EBC), and urine

BACKGROUND AND AIM: Subway exposure health effects are still unknown. We analyzed particle and metal exposure in the PBZ, EBC and urine of subway workers METHODS: PBZ of nine station agents, locomotive operators and security guards was sampled during 6-h shifts over two weeks. Urine and EBC samples were collected pre- and post-shift. Mass concentrations of PM10, PM2.5 and their metal constituents were determined in PBZ, urine and EBC, along with ultrafine particle (UFP) number in PBZ and EBC. Urine and EBC metal concentrations were standardized by creatinine and EBC volume, respectively, and log-transformed. RESULTS:PBZ PM mass concentrations were above the WHO guideline for indoor air but varied significantly between jobs. Locomotive operators had the highest exposure (189 and 137 μg/m3 for PM10 and PM2.5, respectively), while station agents had the highest UFP exposure (1.97x104 #/cm3). Only Al, Fe and Zn in both PM2.5 and PM10 and Cu and Mn in PM2.5 were above the limit of quantification. By mass fraction, Fe, Cu, Al and Zn were the most abundant. Security guards had the highest Al exposure in both PM2.5 and PM10, while locomotive operators had the highest PM10 Fe exposure. In EBC, the pre/post-shift metal concentrations ordered ZnCuNiBaMn. Security guards had the highest EBC metal concentrations, particularly Zn and Cu. Urinary concentrations ordered SiZnMoTiCuBa≈NiCo. Station agents and locomotive operators had the highest Si and Zn concentrations, respectively. Post-shift EBC Zn and Cu were associated with Zn and Cu concentrations in PM10 and with post-shift urinary Zn and Cu concentrations. Particle number in EBC was significantly correlated with UFP number in PBZ. CONCLUSIONS:This is the first study exploring a triple assessment of particle and metal exposure in a subway. The use of EBC in addition to urine seems more informative for individual airborne exposure biomonitoring in subways. KEYWORDS: particulate matter, ultrafine particles, mass concentration, exposure biomarquer

Particle and metal exposure in Parisian subway: Relationship between exposure biomarkers in air, exhaled breath condensate, and urine.

Subway particulate toxicity results from in vitro and in vivo studies diverge and call for applied human research on outcomes from chronic exposures and potential exposure biomarkers. We aimed to (1) quantify airborne particulate matter (PM) concentrations (mass and number) and metal concentrations in exhaled breath condensate (EBC), urine, and PM; (2) investigate their associations (EBC vs. PM vs. urine); and (3) assess the relevance of EBC in biomonitoring. Nine subway workers in three jobs: station agents, locomotive operators and security guards were monitored during their 6-h shifts over two consecutive weeks. Six-hour weighed average mass concentrations expressed as PM10, PM2.5 and their metal concentrations were determined. Urine and EBC samples were collected pre- and post-shift. Ultrafine particle (UFP) number concentrations were quantified in PM and EBC samples. Metal concentrations in urine and EBC were standardized by creatinine and EBC volume, respectively, and log-transformed. Associations were investigated using Pearson correlation and linear mixed regression models, with participant's ID as random effect. PM concentrations were below occupational exposure limits (OEL) and varied significantly between jobs. Locomotive operators had the highest exposure (189 and 137μg/m3 for PM10 and PM2.5, respectively), while station agents had the highest UFP exposure (1.97×104 particles/cm3). Five metals (Al, Fe, Zn, Cu, and Mn) in PM2.5 and three (Al, Fe, and Zn) in PM10 were above the limit of quantification (LOQ). Fe, Cu, Al and Zn were the most abundant by mass fraction in PM. In EBC, the metal concentrations in decreasing order were: Zn>Cu>Ni>Ba>Mn. Security guards had the highest EBC metal concentrations, and in particular Zn and Cu. Urinary metal concentrations in decreasing order were: Si>Zn>Mo>Ti>Cu>Ba≈Ni>Co. All urinary metal concentrations from the subway workers were similar to concentrations found in the general population. A statistically significant relationship was found for ultrafine particle number concentrations in PM and in EBC. Zn and Cu concentrations in post-shift EBC were associated with Zn and Cu concentrations in PM10 and with post-shift urinary Zn and Cu concentrations. Therefore, EBC appears a relevant matrix for assessing exposure to UFP in human biomonitoring when inhalation is a primary route of exposure. We found different temporal variation patterns between particle and metal exposures in three matrices (PM, urine, EBC) quantified daily over two full weeks in subway workers. These patterns might be related to metal oxidation, particulates' solubility and size as well as their lung absorption capabilities, which need to be further explored in toxicological research. Further research should also focus on understanding possible influences of low chronic exposures to subway particulates on health in larger cohorts.

Characterizing Fuel Use and Emission Hotspots for a Diesel-Operated Passenger Rail Service.

Spatially varying diesel locomotive fuel use and emission rates (FUERs) are needed to accurately quantify local emission hotspots and their health impacts. However, existing locomotive FUER data are typically not spatially resolved or representative of real-world locomotive operation. Therefore, existing data are of limited use in quantifying the spatial variability in real-world FUERs. The objectives of this work are to quantify spatial variability in locomotive FUERs and identify factors differentiating hotspots from non-hotspots. FUERs were measured based on real-world measurements conducted for the Piedmont passenger rail service using a portable emission measurement system. FUERs were quantified based on 0.25 mile track segments on the Piedmont route. Hotspots were defined as segments in the top quintile of segment-average FUERs. On average, hotspots contributed 40-50% to trip fuel use and emissions. Hotspots were typically associated with low-to-medium speed, and high acceleration and grade. In contrast, non-hotspots were associated with high speed, and low acceleration and grade. Hotspots were typically located near populated areas and, thus, may exacerbate air pollutant exposure. The method demonstrated here can be applied to other passenger train services to assess key trends in hotspot locations and factors that explain the occurrence of hotspots.

Substantiation of performance indicators of mine monorail locomotives

Mine transport is an integral part of mining process. The performed analysis of modern monorail autonomous locomotives indicates that this type of underground auxiliary transport is the most promising today due to a number of advantages that were identified in this study. To assess performance indicators of mine monorail locomotives, a number of characteristics are currently used, for instance, the dependences between several parameters of propulsion system operation. The type of characteristic is determined by an independent variable to be selected from the list of the operational or design parameters. To substantiate performance indicators of autonomous mine suspended monorail locomotives, the authors proposed the relationship between the characteristics of the traction energy chain equipment and the diesel locomotive propulsion system efficiency factor. To assess the efficiency of mine suspended monorail locomotive operation, a composite indicator for assessing efficiency of various types of traction was proposed: the operational efficiency factor. This indicator takes into account varying the efficiency factor of the energy chain units depending on their operating modes. When determining the functional dependencies of varying the efficiency factor of power and auxiliary units of monorail locomotives, a grouping of the main parameters according to the features depending on the economic characteristics of the propulsion system and its operating modes was proposed. The operational efficiency factor of the locomotive as a whole is determined both by the economic characteristics of all units of its energy chain and by the modes of their operation.