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Referring to the lecture held on 16th Mini-Conference on Vehicle System Dynamics, Identification and Anomalies, Budapest, 5-7 November 2018, the accredited Notified Body started the conformity assessment process of the modernized bogie-locomotive body connection of MÁV-START Class V63 electric locomotives running with Ganz-MÁVAG UFC-type bogies, in 2017. Since the planned modification of the locomotives was delayed, the Conformity Assessment Body could perform the necessary riding quality and noise test in the summer of 2020 instead of September 2018. The study presents the modification carried out on the locomotives, the test procedures, and the test results. The aim and the novelty of the research was to apply the latest developments of the test procedures on a modified, existing rolling stock. The conformity for the new requirement makes challenges for the development of testing even if theoretically a well-known test method is applied. The article gives an example for the application of a classic test method combined with of the new possibilities, that makes unnecessary the use of additional railway test cars.

The current standard for evaluating road conditions worldwide relies primarily on the Pavement Condition Index (PCI) and the International Roughness Index (IRI). The IRI can be further calculated to obtain the Riding Quality Index (RQI). To assess pavement damage, various imaging equipment is commonly utilized, providing consistent results that align with actual road conditions. For roughness detection, the Laser Profilometer offers excellent results but may not be suitable for rural roads with poor conditions due to its high inspection cost and the need for a stable environmental setting. Therefore, there is a pressing need to develop cost-effective, rapid, and accurate roughness inspection methods for these roads, which constitute a significant portion of the road network. This study examined the relationship between PCI and RQI using nonlinear regression on 30,088 valid pavement inspection records from various regions in China (totaling 24,624.222 km). Our objective was to estimate RQI solely from PCI data, capitalizing on its broad coverage and superior accuracy. Additionally, we explored how PCI levels impact RQI decay rates. The models in this study were compared to several models published in previous studies at last. Our findings indicate that the model performs best for low-grade roads with low PCI scores, achieving over 90% accuracy for both cement concrete and asphalt concrete pavements. Furthermore, different levels of pavement damage have distinct effects on RQI decay rates, with the most significant impact observed when the pavement is severely damaged. The models in this study outperformed all the other available models in the literature. Consequently, under limited inspection conditions in rural areas, pavement damage inspection results can effectively predict riding quality or roughness, thereby reducing inspection costs. Overall, this study offers valuable insights but has limitations, including limited global generalizability and the model’s applicability to high-grade roads. Future research is needed to address these issues and enhance practical applications.

People use trains as a means of transportation to travel to various nearby and distant destinations, resulting in an increasing amount of time spent inside such vehicles. Consequently, railway transportation sectors are focusing significantly more on enhancing passengers’ demand and level of satisfaction, including but not limited to high-speed travel, safety, and riding comfort. This paper provides a state-of-the-art review of available solutions for reducing undesired vibrations that have a substantial impact on improving the critical velocity limits of trains, maintaining the quality of riding comfort, and resolving safety concerns. In this regard, the solutions proposed for train vibration control are divided into two main categories: direct and indirect solutions. The direct solutions are those methods that are applied directly to trains’ bodies or bogies to attenuate the undesired vibrations, for example, improving the suspension/damper system, implementing active/semi-active control strategies, or applying various carriage optimization design modifications. Indirect solutions, on the other hand, are those that could indirectly affect trains’ vibrations, for example, controlling vibrations in railway bridge structures during train passages. Since the identification of vibration characteristics is assumed to be the first step in choosing proper solutions, particularly for active or semi-active control implementations, this review has examined the literature pertinent to modal identification of trains and railway infrastructures. Additionally, despite the installation of dampers between the bogie and suspension, the train’s equation of motion, and consequently, the vibration control of the bogie, has relied on the sky-hook model for decades. The fundamental problem for systems whose control strategies are based on the sky-hook concept is that the ‘sky’ does not actually exist. A solution to solve the sky-hook logic issue is using tuned rotatory inertia dampers and active rotatory inertia drivers which is addressed in this paper as well. Finally, it is concluded that these three solutions – employing a suspension/damper system in the bogie, an elastic connection for the train’s under-chassis-suspended equipment, and a ballastless railway – can practically mitigate vibration and noise in a train.

Comfort is a significant factor that affects passengers’ choice of autonomous vehicles. The comfort of an autonomous vehicle is largely determined by its control algorithm. Therefore, if the comfort of passengers can be predicted based on factors that affect comfort and the control algorithm can be adjusted, it can be beneficial to improve the comfort of autonomous vehicles. In view of this, in the present study, a human-driven experiment was carried out to simulate the typical driving state of a future autonomous vehicle. In the experiment, vehicle motion parameters and the comfort evaluation results of passengers with different physiological characteristics were collected. A single-factor analysis method and binary logistic regression analysis model were used to determine the factors that affect the evaluation results of passenger comfort. A passenger comfort prediction model was established based on the bidirectional long short-term memory network model. The results demonstrate that the accuracy of the passenger comfort prediction model reached 84%, which can provide a theoretical basis for the adjustment of the control algorithm and path trajectory of autonomous vehicles.

Roughness is widely used as a primary measure of pavement condition. It is also the key indicator of the riding quality and serviceability of roads. The high demand for roughness data has bolstered the evolution of roughness measurement techniques. This study systematically investigated the various trends in pavement roughness measurement techniques within the industry and research community in the past five decades. In this study, the Scopus and TRID databases were utilized. In industry, it was revealed that laser inertial profilers prevailed over response-type methods that were popular until the 1990s. Three-dimensional triangulation is increasingly used in the automated systems developed and used by major vendors in the USA, Canada, and Australia. Among the research community, a boom of research focusing on roughness measurement has been evident in the past few years. The increasing interest in exploring new measurement methods has been fueled by crowdsourcing, the effort to develop cheaper techniques, and the growing demand for collecting roughness data by new industries. The use of crowdsourcing tools, unmanned aerial vehicles (UAVs), and synthetic aperture radar (SAR) images is expected to receive increasing attention from the research community. However, the use of 3D systems is likely to continue gaining momentum in the industry.

An increasing number of load applications has caused permanent deformation that leading to longitudinal depressions in the wheel paths and small upheavals at the sides and subsequently effects the ride quality for road users. To address this issue, modifying asphalt mixtures using Forta-Fi fibre was introduced. This paper focuses to assess the permanent deformation and resistance to rutting of the asphalt mixtures containing Forta-Fi fibre. In this study, the influence of Forta-Fi fibre on asphalt mixtures was investigated by incorporating four different percentages of the fiber (0%, 0.3%, 0.5%, and 0.7%). The asphalt mixtures were prepared using a conventional bitumen 60/70 penetration grade as the base binder. Compacted specimens were subjected to dynamic creep testing with deviator stress levels of 207 kPa and 500 kPa, performed over 3600 cycles at a 60°C. The findings demonstrate that the inclusion of 0.3% Forta-Fi fiber in asphalt mixtures tested under deviator stress loads of 207 kPa and 500 kPa increased the creep stiffness by 26.1% and 43.1%, while the permanent deformation decreased by 18.4% and 43.8% compared to specimens without the Forta-Fi fibre. Additionally, the rutting values showed a reduction of 12.2% and 24.3% in the respective stress conditions. In contrast, an excessive percentage of Forta-Fi fibre was added, the creep stiffness exhibit reduce as increases permanent deformation and potential to rutting. This outcome is attributed to the impact of fibre components on the elastic behavior of the mixtures. In conclusion, the inclusion of 0.3% Forta-Fi fibre in the specimens resulted in improved resistance to rutting and overall better performance compared to conventional mixtures.

A semi-active suspension system using Magnetorheological (MR) damper overcomes all the inherent limits of passive and active suspension systems and combines the advantages of both. This paper gives a concise introduction to the suspension system of a passenger vehicle which is presented along with the analysis of semi-active suspension system using MR fluid dampers based on Bingham model. MR dampers are filled with MR fluids whose properties can be controlled by applying voltage signal. To further prove the statement, a quarter car model with two degrees of freedom has been used for modeling the suspension system the sprung mass acceleration of passive suspension system has been compared with the semi-active suspension system using the Bingham model for MRF damper. Simulink/MATLAB is used to carry out the simulation. The results drawn show that the semi-active suspension system performed better than the passive suspension system in terms of vehicle stability.

In recent years, the importance of the bicycle for everyday mobility has increased significantly in Germany. In order to increase the attractiveness of cycle traffic, the provision of safe cycle paths in a good structural condition is necessary in addition to the expansion and new construction of cycling infrastructure. Against this background, the Federal Ministry of Digital and Transport has been funding the research project “Recording and Assessment of the Structural Condition of Urban Cycle Paths” since September 2021. In cooperation with Schniering GmbH and the engineering office Feiler und Hänsel GbR, the University of Applied Sciences Aachen is working on the development of a suitable measurement and assessment procedure. The methods used so far in Germany to record and assess the condition of cycle paths are very much based on the established methods for road condition monitoring and assessment. However, the damage characteristics on cycle paths as well as their effects on road safety aspects, riding comfort and structural value preservation can only be compared with roads to a somewhat limited extent. For this reason, extensive structural assessments of cycle paths were carried out in the research project and a damage catalogue was developed for the recording and assessment of the condition of urban cycle paths. The relevant types of damage are assigned to the following characteristics groups: unevenness, rolling resistance, substance characteristics and vegetation. Based on the results, requirements for the measurement technology and its accuracy could be defined. The conceptual design of a measuring vehicle by the project partner Schniering GmbH will be completed this year and its use tested on various urban cycle paths.

A passenger railway vehicle’s lightweight design is an efficient technique of reducing energy consumption and dynamic forces between wheel and rail. However, light design results in resonant vibration in a car body. To restrain resonant vibration, a correlation between the suspended equipment variables and the car body’s modal frequency was investigated in this paper. A rigid–flexible general model was developed to examine the impacts of different equipment suspended under the chassis based on mass, location, and frequency on the car body mode. In addition, the numerical model is validated through the experimental result in terms of ride quality. The results demonstrate that the underframe equipment’s suspension characteristics have a significant impact on the mode of the car body, particularly the frequency of the first bending mode. Equipment with a considerable mass should be suspended near the center of the car body to optimize the frequency of the car body’s high-frequency bending. The weight of the equipment has a significant impact on the car body’s first bending frequency. The frequency of heavy equipment should be low enough to promote high-frequency transmissibility and improve the vibration characteristics of the car body.

The suspension system consists of tires, tire air, springs, shock absorbers, and connections that facilitate the relative movement among the axles and the automobile. Although ride quality and road holding/handling are mutually exclusive, suspension components nevertheless need to provide both. Adjusting suspensions requires striking the ideal balance. Maintaining maximum contact between the road wheel and the road surface is crucial for the suspension. The vehicle’s suspension greatly affects its handling; since the vehicle must operate on all types of terrain and retain ideal steering geometry, an adaptable system of suspension should be employed. The EATV’s suspension elements will be designed in Solid works, and the resulting model will be examined utilizing Ansys software for optimizing design variables while taking into account how they may affect the efficiency of other automobile parts through simulator testing.