Car Rolling Research Articles

Mechanically Driven Self-Healing MXene Strain Gauges for Overstrain-Tolerant Operation.

Compliant strain gauges are well-suited to monitor tiny movements and processes in the body. However, they are easily damaged by unexpected impacts in practical applications, limiting their utility in controlled laboratory environments. This study introduces elastic microcracked MXene films for mechanically driven self-healing strain gauges. MXene films are deposited on soft silicone substrates and intentionally stretched to create saturated microcracks. The resulting device not only has high sensitivity but also can recover its original sensing capability even after experiencing failure-level overstrains. This electrical self-healing ability is achieved through the elastic rebound of the substrate, which autonomously restores the microcracked morphology of the MXene film. The MXene strain gauge can withstand overextension, twisting, impact forces, and even car rolling. The device is also resilient to touch-induced damage during monitoring of physiological motions. The mechanically driven self-healing strategy may effectively improve the durability of highly sensitive strain sensors.

Additive manufacturing — a new vector in the production and repair of rolling stock

The influence of the fourth industrial revolution, known as Industry 4.0, on modern industrial production and social life is analyzed. The main advantages of Industry 4.0 are presented, such as increasing productivity and occupational safety, developing new products and materials, as well as increasing the competitiveness of products. Special attention is paid to additive technologies and their role in modern engineering within the framework of the Industry 4.0 concept. The methods of additive technologies, their classification by materials and production methods, as well as their various applications in various industries are described in detail. An example of the successful use of additive technologies is presented on the example of JSC Uralvagonzavod Scientific and Production Corporation, where molds and rods for casting parts with high speed and quality are created using 3D printers. The project of introducing 3D printers into the service depots of the directorate of motor car rolling stock of JSC Russian Railways is considered, with an emphasis on the economic and temporary benefits from the use of additive technologies. The concept of introducing additive technologies in the maintenance and repair of rolling stock involves the creation of support depots on the railway network of JSC Russian Railways. In conclusion, the importance of training highly qualified specialists in the field of additive technologies and the need to develop educational programs to train future employees capable of solving complex tasks of creating and applying new industrial technologies is presented. Special attention is paid to synergetic approaches in education to combine learning with scientific activity and the creation of innovative technological solutions.

Fault diagnosis of railway freight car rolling bearings based on ACMD and improved MCKD

To address the issue of accurately extracting fault characteristic information of railway freight car bearings under noisy conditions, this paper proposes a fault diagnosis method based on Adaptive Chirp Mode Decomposition (ACMD) and an optimized Maximum Correlation Kurtosis Deconvolution (MCKD) using a Sparrow Search Algorithm Combining Sine-Cosine and Cauchy Mutation (SCSSA). Firstly, ACMD is used to decompose and reconstruct the original fault signal to obtain several Intrinsic Mode Functions (IMFs). Then, the IMFs are filtered according to the Gini coefficient indicator, with the IMF having the largest Gini coefficient selected as the optimal component. Secondly, the SCSSA is employed to iteratively optimize the filter length L, fault signal period T, and displacement parameter M in the MCKD algorithm, determining the optimal parameter combination for MCKD. This avoids the limitations of manual settings and enhances the accuracy of fault diagnosis. The optimized MCKD is then applied to the optimal component, and deconvolution is performed using maximum correlation kurtosis as the criterion to extract fault characteristic information through its envelope spectrum. To verify the effectiveness and generalizability of the proposed method, simulations, experimental signals from the Case Western Reserve University Bearing Center, and actual measured signals from railway freight car bearing 353130B are used to analyze inner ring faults. The experimental results demonstrate that the method can accurately extract fault characteristic information of railway freight car bearings under noise interference and identify the fault type.

A short review of the ADAS progress in the last decade and the potential concept of Human-Machine Symbiosis (HMS)

Abstract This short review highlights the main sensor structures that are used in the ADAS (Advanced Driver Assisted System) field, in order to outline the progress at this moment (2023). Starting from this achieved level, we have proposed another approach to the ADAS problematics, regarding the prospects for development after the current moment, a different perspective than the one that has AV (Autonomus Vehicle) as its endpoint. Computer Assisted Driving represents a necessary and sufficient solution for increasing traffic safety in the near future. The integrated driver concept in the assisted environment implies a symbiotic human-machine collaboration. This collaboration requires a psychological acceptance of the ADAS system on behalf of humans, as an essential part of the current and future automobile. The progress highlighted by the documentation undertaken allows us to imagine a concept of a symbiotic human-machine system, based on the communication between ADAS and an external computing resource that assists the driver, based on the long analysis of recorded car events. Future automobiles must include an ADAS system that provides a subtle human-machine synapse, based on a series of computerized warnings to the driver generated in a timely manner, resulting from the high predictive capacity of AI-DLM algorithms. The computing speed of the local ADAS algorithms will be supplemented by the external server processing resource, accessed at the right time, to resolve an unexpected deadlock in the car roll.

Simultaneous fault detection and robust control for a dynamic observer-based switched time delay systems with car roll dynamic application

In this study, the issue of simultaneous fault detection and control (SFDC) for a class of switched linear systems with input and state delays is being addressed. A detector/controller unit (dynamic observer/observer-based controller) is suggested for a residual generation that simultaneously takes into account the control and fault detection objectives using specific performance indices. It is assumed that the delay will fluctuate within a range with a lower bound that is not zero. Based on a Lyapunov–Krasovskii functional (LKF), and thanks to the free-weighting matrix and projection lemma, a new sufficient condition for developing a new method is put forth in terms of a set of linear matrix inequalities (LMIs). To illustrate how well the suggested results work, the proposed method is applied to a vehicle roll dynamic.

Mathematical models and structures of the vehicle lateral stability stabilization system

Currently, intensive research is being carried out to improve the operational characteristics of the car: vibration protection, smoothness, stability, controllability. These properties are largely determined by the characteristics of the vehicle suspension, which provides a connection between the carrier system and the wheels of the vehicle. Significant attention is paid to the development of active suspensions, in which additional actuators are used to form the necessary characteristics, in particular, linear DC motors. The use of active actuators allows you to control the position of the car body, including its lateral roll. In the article, relations are obtained that establish the dependence of additional elastic deformations in the suspension and the car's roll angle on the centrifugal force in a stationary mode. When developing a linearized mathematical model of the control object for the study of non-stationary modes, a two-mass design scheme was used and operator equations were obtained that take into account the elastic-dissipative properties of the sprung and unsprung parts of the car, as well as an additional control action created by the actuator. It is shown that the dynamic properties of the studied control object can be approximately described by the transfer functions of a second-order aperiodic link or an oscillatory link. For the first case, a single-loop system was developed, closed in terms of the angle of heel with a PID controller. In the second situation, it is advisable to use a two-loop system with an internal flexible feedback loop for suspension deformation and an external loop closed for the roll angle using a PID controller. The possibility of forming a feedback signal on the strain rate of the suspension in the wind circuit with the help of an EMF sensor of a linear DC motor is shown.
 On the basis of the block diagram, a computer model of the system was developed, and for typical parameters of the control object, a study was made of transient processes of working off a disturbance in the form of a change in centrifugal force. Based on the simulation results, it was found that the use of the developed ACS provides high accuracy in stabilizing the vehicle roll angle.

Establishing a novel adaptive fuzzy control algorithm for an active stabilizer bar with complex automotive dynamics model

Rollovers can cause many hazards to the passengers in the car. The main cause of this problem is the driver's sudden steering at high speed to avoid an obstacle or enter a roundabout. To limit this phenomenon, it is necessary to equip the car with an active stabilizer bar. In this article, we use a new fuzzy control method to direct an active stabilizer bar. This method is established based on five points of view regarding the stability and responsiveness of the system, so it is called the novel adaptive fuzzy algorithm (NAFC). This is a completely new point in the article compared to previous studies. A combined dynamics model that is a fusion of the seven DOFs spatial dynamics model and the three DOFs motion model. The simulation and calculation occur in the Simulink® interface, with two cases representing the steering angles J-turn and Fish-hook. The speed of the car is changed according to three specific values. According to the calculation results, the vehicle body roll angle is greatly reduced when using active stabilizer bars controlled by the novel adaptive fuzzy algorithm. Besides, the minimum dynamic force value at the rear wheel is better guaranteed. The car's roll index is also sharply reduced when applying this algorithm to the hydraulic stabilizer bar model. In addition, rollover occurs when the car steers the J-turn at v3 and the fish hook at v2 and v3 (if stabilizer bars are unavailable). Meanwhile, car’s stability is always guaranteed in the case of a car with a stabilizer bar using the NAFC algorithm. The article's achievements can be used as a basis for developing more complex control algorithms in the future.

Correlation between the Injury Site and Trauma Mechanism in Severely Injured Patients with Blunt Trauma.

In patients with severe injury, predicting the injury site without using advanced diagnostic modalities can help formulate a diagnosis and treatment plan based on the suspected injury site. This study aimed to determine the correlation between the injury site and trauma mechanism in severely injured patients with blunt trauma. We retrospectively analyzed the clinical characteristics-including age, sex, date of emergency room (ER) visit, time of injury, trauma mechanism (car accident, motorcycle accident, bicycle accident, pedestrian accident, fall, slipping and rolling down, crush injury, assault, and others), final diagnosis, injury severity score, abbreviated injury scale (AIS) score, and injury site-of 1,245 patients in a tertiary trauma center. There was a strong correlation between certain injury sites and specific trauma mechanisms. In particular, most trauma mechanisms were associated with injury to the head and neck, as well as the chest, with a combined frequency of >40.0%. Moreover, when using one-way analysis of variance and Bonferroni's post hoc tests, there were significant differences in AIS scores 1, 3, 4, and 5 for each trauma mechanism. Generally, when patients with severe injury present to the ER, the injury site can be predicted upon initial assessment based on the trauma mechanism. Based on our study, the injury site predicted by a specific mechanism should be checked repeatedly and additionally through physical examination and imaging tools. This can reduce misdiagnosis and help with accurate diagnosis and treatment.

Prospective of Magnesium and Alloy-based Composites for Lightweight Railway Rolling Stocks

Magnesium and its alloy have superior characteristics and matches to great potential in railway rolling stocks. The low density and high strength make it ideal for lightweight applications, exceptionally for car bodies and rolling stocks. In this study, a comprehensive review has been carried out on magnesium alloy towards its prospective in railroad vehicles, emphasizing fatigue damage, vibration, energy savings, and overcoming wear or friction loss. Furthermore, with better stiffness and strength, the weight reduction contributes to the better energy and fuel-saving for low-speed trains than bullet and high-speed trains. However, the potential application of magnesium and its alloy has a colossal study gap in the railway industry's processing, fabrication, and maintenance that needs further studies and research.

The multi-component coupling horizontal vibration modeling technology of the high-speed elevator and analysis of its influencing factors

Horizontal vibration of a high-speed elevator can seriously influence the safety, stability, and ride comfort of the elevator during the operation. The construction of an accurate and robust dynamic model for horizontal vibration is the key to vibration control and suppression. In this article, the modeling and influencing factor analysis of the horizontal vibration of the high-speed elevator car are performed considering multi-component coupling. The rigid flexible coupling of the traction ropes and the elevator car system, the rigid irregularity perturbation generated by the manufacturing and installation errors of the guide rails, and the vibration inconsistency between the elevator car and car frame are considered in the modeling process. Based on the coupling system of the traction rope, elevator car, elevator car frame, guide rails, and rolling guide shoes, the kinematic horizontal vibration equation is established by using the generalized Hamilton’s principle. The solution of the horizontal vibration of the elevator car is derived based on the Galerkin method and MATLAB/Simulink software, and the influence of the perturbation frequency, irregularity perturbation type, and operating velocity on the horizontal vibration of the elevator car is analyzed. The KLK2 high-speed elevator is taken as a case study. Compared with the measured data, the mean absolute percentage error (MAPE) of the proposed model for maximum peak-to-peak (max [Formula: see text]) and [Formula: see text] peak-to-peak ([Formula: see text] [Formula: see text]) of the horizontal vibration acceleration is 6.08% and 5.16%, respectively, while the MAPE of a four degree-of-freedom model for the two is 16.74% and 7.35% and the MAPE of a distributed-parameter model for the two is 10.66% and 6.97%, respectively. The effectiveness of the proposed model is verified.

Fatigue Resistant Aerogel/Hydrogel Nanostructured Hybrid for Highly Sensitive and Ultrabroad Pressure Sensing (Small 1/2022)

High-Resolution Sensing In article number 2104706, Jingbin Zeng, Zifeng Yan, Yadong Yin, and co-workers fabricate a hybrid pressure aerogel/hydrogel sensor by integrating a polypyrrole nanotube-structured aerogel into a polyacrylamide hydrogel. With high stretchability and self-healing property, the hybrid polymer sensor exhibits stable performance in high-resolution sensing of a wide range of pressure from human physiological signals to significant stress caused by car rolling.

Influence of lubrication on the friction and wear of car rolling bearings

The goal of the work is to develop computational and experimental approaches to determine the wear resistance of friction units with internal contact of cylinders with slip. The scientific novelty consists in taking into account the slip for calculating the friction path and the wear of the cylinders with internal contact and the proposed method for identifying the parameters of the wear law based on the test results. Practical value is the proposed methods to account load, slip and lubrication conditions on the resource for the design of friction units. The dependences for determining the friction path for internal rolling of cylinders have been considered. The design of an experimental setup for studying friction and wear of cylinders with slip has been proposed. Experimental studies have been carried out: paths of friction; wear of surfaces both with a key and without a key; the effect of lubricants on wear has been studied. The form of the wear model is proposed to determine the effectiveness of methods for increasing wear resistance. The method for determining the parameters of the wear law has been implemented based on the test results. The results show the efficiency of copper powder as an additive to a lubricant. It has been established that the wear of cylinders with a key is greater than the wear of cylinders without a key due to different friction paths. A practical example of determining the wear of a car hub shaft using the wear patterns is presented.

Selection of mathematical model of on-board capacity energy storage as element of hybrid traction unit of motor car rolling stock

The authors of the study work out to determinate of the mathematical model of supercapacitors as an object of an electric traction system capable of providing non-encumbering of obtaining research results and correct reproduction of energy exchange processes in conditions of repeated-short-term modes of traction load operation. In paper, authors make a comparative assessment of six models for the possibility of their integration into the model of electric traction systems with on-board placement of the energy storage.

Analysis of the water flow inside tire grooves of a rolling car using refraction particle image velocimetry

In order to better understand the hydroplaning phenomenon, local velocity measurements of water flow are performed inside the tire grooves of a real car rolling through a water puddle. Velocity fields are obtained by combining refraction Particle Image Velocimetry (r-PIV) illumination, seeding fluorescent particles, and either the classical two dimensional two components or the two dimensional three components stereoscopic recording arrangements. The presence of some bubble columns inside the grooves is highlighted by separate visualization using the fluorescent contrast technique evidencing two phase flow characteristics. A simple predictive model is proposed supporting the r-PIV analysis. It provides useful information to adjust the focusing distance and to understand the effect of the bubble column presence on the recorded r-PIV images, especially for the seeding particles located in the upper part of the grooves, as fluorescent light is attenuated by the bubbles. Also, the predictions provided by the model are compatible with the measurements. The velocity fields inside the grooves are analyzed using ensemble averaging performed over a set of independent snapshots, recorded with the same operating parameters. The variability of the longitudinal velocity distribution measured in a groove for several independent runs is explained by different mechanisms, like the random position of fluorescent seeding particles at various heights of the groove, the hydrodynamic interactions between longitudinal and transverse grooves, and the random location of the transverse grooves from one run to another. Three velocity components in cross sections of the longitudinal grooves are obtained using the stereoscopic arrangement. They are compatible with the presence of some longitudinal vortices assumed in the literature. The number of vortices is shown to be dependent on the aspect ratio characterizing a groove's rectangular cross section. We demonstrate, from measurements performed for several car velocities, that the velocity distribution inside longitudinal grooves shows self-similarity when using specific dimensionless length and velocity scales. Hydrodynamic interactions between longitudinal and transverse grooves are discussed on the basis of a mass budget; a fluid/structure interaction mechanism is proposed in order to correlate the overall direction of the flow in a transverse groove with its location inside the contact zone. Finally, some physical mechanisms are suggested for the birth of longitudinal vortices.

Стендовая отработка алгоритмов диагностирования подшипников качения бортовой системы диагностики и прогноза остаточного ресурса основных и вспомогательных узлов МПВС

The experimental study of bearing vibration and use of the fast Fourier transformation (FFT) as an intelligent tool for diagnosing and identifying bearing defects of motor car rolling stock units (MCRSU) is presented. It is shown that the use of new means of technical diagnostics due to the detection of malfunctions at an early stage of their development reduces the cases of violations of the normal operation of cars and rolling stock. The article presents the results of vibration diagnostics of rolling bearings on the stand, spectral characteristics are obtained for bearings with rolling body defects, internal track and external track. During the bench tests, a specially developed intelligent vibration sensor was used as a vibration sensor, consisting of a sensitive element, a vibration accelerometer, the necessary interfaces and an analogdigital converter. The radial arrangement of sensors in diagnostic systems in repair depots and on-board systems makes it difficult to diagnose defects associated with the appearance of defects under the influence of axial loads, primarily separator defects. Bench tests using intelligent sensors and cloud services on the Internet showed the possibility of creating a mobile system for diagnosing the technical condition of bearing units of motor-car rolling stock and freight car units.

Анализ технических средств диагностирования моторвагонного подвижного состава при работе машиниста «в одно лицо»

The article covers the safety challenges of motor car rolling stock (MCRS). The indicators of traffic safety violations on the Sverdlovsk Railway sections for 2020 are analysed, and their comparison with the indicators for 2019 is made. The analysis was carried out for each cause of the violation separately: failures, technological violations and transport accidents. The devices for ensuring traffic safety and the peculiar features of operation of the “Barrier” hardware and software complex installed on the MCRS are reviewed.

RELIABILITY CRITERION AND A MODEL FOR DETERMINING THE OPTIMAL SPEED OF MOVEMENT ON AUTOMOBILE ROADS IN WINTER SLIDING CONDITIONS

The article presents a model for establishing the optimal speed of movement on highways, taking into account the determination of the braking distance in winter slippery conditions. According to the research results, it was established that the main criterion for the formation of road accidents on highways in winter slippery conditions is the drivers' underestimation of the adhesion qualities of road surfaces. The main criterion of the model under consideration is the interaction of the car wheel (braking distance) with the road (adhesion coefficient) and is a complex that characterizes the stability of the car rolling over on slippery surfaces and the driver's actions in making an effective decision and the duration of the reaction time. In the proposed mathematical model, the accident rate on a slippery road is estimated by the coefficient of adhesion of icy road surfaces, the value of the load or the average wheel pressure. Also, the frequency of load application, the amount of deflection of the coating (at an air temperature above +20 ° C), rolling resistance, the coefficient of adhesion of the car wheel to the coating. One of the main characteristics of the model is a subsystem - the average pressure p = Q / S (S is the area of the imprint of the wheel, cm²), etc. Thus, in the process of analyzing the results of the causes of road traffic accidents, the factors of the driver's reliability and the decisions made will be taken into account, which depend on the speed of vehicles in any condition of the road surface.

Prediction of the subjective impression of passenger car roll dynamics on the driver based on frequency-domain characteristic values

Characteristic values are essential for the design and assessment of driving dynamics during the early stages of the development process of passenger cars. Compared to other aspects of vehicle dynamics however, the relationship between measurable parameters and the subjective perception of vehicle roll dynamics has not been researched extensively. In this paper, a study is presented in which several variants of a vehicle with an electronically controlled suspension were rated by test subjects regarding its roll dynamics and measured in a standardised driving manoeuvre. The subjective ratings and objective characteristic values were then used to derive models to predict the subjective liking of several roll dynamics aspects based on objective frequency-domain parameters which could be achieved with relatively high accuracy. The resulting prediction models were validated using measurements of additional vehicles even though this only allowed for a rough validation as no subjective ratings were available for the validation set. Nevertheless, the predictions for the validation variants seemed plausible and reflected the basic expectations regarding the vehicle characters of the validation set. The results of this investigation thus laid a good foundation for follow-up studies to further increase the reliability and robustness of the prediction models.

Development of a system for electric power consumption control by electric rolling stock on traction tracks of locomotive depots

The paper deals with the problem of increasing the energy efficiency of train traction. The analysis of energy resources consumption of JSC “Russian Railways” is made and options for saving fuel and energy resources of the company are formulated by reducing unproductive losses of electricity by electric rolling stock of railways during their standstill on traction tracks and at points of turnover of locomotive crews. The analysis of existing methods of control of electric power consumption by electric rolling stock on traction tracks of locomotive depots is performed. The considered manual control method has the following disadvantages: the lack of completeness, timeliness and reliability of data on electricity consumption. The second method, which consists in installing measuring systems on the feeders of traction tracks, has the following disadvantages: it does not allow automated metering and rationing of electricity with details on the operations performed (shunting movements, heating of electric locomotives), drivers, series of electric rolling stock, as well as legitimately attributing unproductive electricity consumption and damage from it to the involved structures (Traction Directorate, Directorate for repair of rolling stock, LLC “STM-Service”, LLC “TMH-Service”, Directorate of motor car rolling stock). The third method, which consists in installing a low-voltage power supply device on traction tracks, is not applicable when operating electric locomotives at low temperatures, since in this case it is necessary to warm up powerful consumers, such as liquid pumps, oil pumps, motor-compressors, motor-fans, etc.; most of the electric rolling stock is not equipped with specialized sockets for connecting a low-voltage power supply device, which limits the serial implementation of this device. An alternative system of control of electricity consumption by electric rolling stock traction on the tracks of the locomotive depot was developed, which has the following advantages: implementation of automated metering and rationing of electricity with details on performed operations (shunting moving, heating of electric locomotives), drivers, series of electric rolling stock; improving the reliability of electricity metering; implementation of the possibility of attributing unproductive power consumption and damage from it to the involved structures (Traction Directorate, Directorate for repair of rolling stock, LLC “STM-Service”, LLC “TMH-Service”, Directorate of motor car rolling stock); elimination of the need for additional research for new series of electric rolling stock being put into operation; development of scientifically-based measures to reduce power consumption.

Analysis of Skid and Rolling Vehicle

Daihatsu Taft Hiline is one of the cars that are widely used for out-of-town travel, to improve the performance of the car in the field, modified cars, modifications made namely the elevation of the car body. The elevation of the car results in a shift in the center of gravity, so that the stability of the car changes. Changing the stability of the car results in skid conditions and the condition of the car rolling. Data processing calculations using the Vehicle Dynamics Turn method, where previously performed calculations to get the car data, car height, car weight, and the location of the center of gravity. Then do skid analysis and rolling to find out the vehicle dynamics that occur in the vehicle. The calculation result of the maximum speed allowed so as not to skid is 66.16 Km / h and the maximum speed allowed so as not to roll is 32.21 Km / h.