Scipedia: Documents published in 2018

Mathematical model simulating the Slurry Pipeline in pressurized conduits

Scipedia content — Thu, 28 Jan 2021 23:29:40 +0100

International audience; Numerous slurry transportation pipeline systems have been built in the past 10 years. At the same time, T. Chakkour & F. Benkhaldoun study in [1] the hydraulic transport of particles in tubes. We investigated in [2] the hydraulic transport of slurry system in horizontal tubes (The Khouribga mines). This mineral pipeline has often been referred to as one of the most challenging projects in terms of operating complexity and system configuration in Morocco. This physical model features a mass and momentum balance for three-fluid model in 1D. It allows to predict the pressure drop and flow patterns. The originality of this work is to present in simplified form a homogeneous single-phase model. The most important advantage of this model is the considerably smaller number of variables to be solved compared to the multiphase model. In this presentation, we give the asymptotic behavior of friction-disharge term f Q 2 that is involved in the last term of motions equation, taking into account the Reynolds number. This allows to understand how the elevation varies, when the flow is very laminar.

Road safety issues of EU funded bicycle network projects in Hungary

Scipedia content — Thu, 28 Jan 2021 23:29:22 +0100

Road safety has improved significantly in Hungary between 2007 and 2013.The number of road fatalities had"br" dropped to levels seen 50 years earlier. In the past few years, however, it has started to increase again."br" Unfortunately, the safety of cyclists is not in the focus of road safety related research activities in Hungary,"br" nevertheless, Road Safety Audits (RSA) are now used more often for cycling infrastructure projects."br" A Road Safety Audit; one of the four pillars of road infrastructure safety management, focuses on the identification"br" of safety deficits in road infrastructure projects by performing an independent, detailed, systematic and technical"br" check. Auditing cycling infrastructure projects have recently become more common as a prerequisite for EUfunded"br" projects. As a result, a number of typical cycling safety issues have been collected from several bicycle"br" network development projects in which the authors were involved. The most frequent safety deficits are presented"br" in this paper.

Transportation Policy Evaluation Using Minority Games and Agent-Based Simulation

Scipedia content — Thu, 28 Jan 2021 23:29:06 +0100

Traffic congestion is an issue regarding the vitality of cities and the welfare of citizens. Transportation systems are using various technologies to allow users to adapt and make different decisions towards transportation modes. Modification and improvement of these systems affect the commuters' perspective and social welfare. In this study, the effect of road flow equilibrium on commuters' utilities with different types of transportation modes will be discussed. A simple network with two modes of transportation will be illustrated and three different cost policies were considered to test the efficiency of reinforcement learning in commuters' daily trip decision-making regarding time and mode. The artificial society of agents is simulated to analyse the results. info:eu-repo/semantics/publishedVersion

Powerflow calculations in powersystems considering traction load

Scipedia content — Thu, 28 Jan 2021 23:28:11 +0100

Nowadays, the negative impact of traction load on power system operation poses a serious problem that may lead to false tripping or even failures of relay protection devices and reduce the quality of electrical energy. This situation is typical for the Zabaikal power system, in which in some areas the share of electricity consumption by railway reaches 70% of total consumption. A computing tool, that would allow simultaneous analysis of the modes, both in the utility's grid and in the traction network, do not exist. The inability to carry out such analysis often leads to inconsistency in the actions of control centers and railway transport authorities, especially when maintenance planning. Mathematic modeling in such software systems as "Mustang", "RastrWin3", "MathCAD", “Matlab/Simulink”, “PSCAD”, “Kortes”. The developed model represents Zabaikal power system and contain detailed railway between substation Razmahnino and substation Shilka. Negative-sequence voltage unbalance factors were calculated for the case of train movement between substation Razmahnino and substation Shilka. Also, the necessity of back-up relays tripping values correction is stated. It was shown that for the powerflow calculations taking into account the traction load, it is rational to use a complex mathematical model, which uses compatible software systems with the ability of quick and easy data exchange.

Safety Performance of the New Bus Rapid Transit System in Haifa, Israel: First Two-Years of Monitoring

Scipedia content — Thu, 28 Jan 2021 23:25:27 +0100

This study explored safety impacts of a new Bus Rapid Transit (BRT) system that was built in the Haifa metropolitan area, Israel, and began its operation in August 2013. Using accident data for Haifa city during the first two-years of the BRT operation, the study examined accident changes on roads with the BRT routes, related to comparison sites, and safety performance of streets with various BRT configurations. In spite of concerns related to the complexity of BRT settings and high traffic volumes, the BRT operation did not lead to a worsening in road safety, while decreasing trends were observed in some accident types and irregular shares of severe or pedestrian accidents did not appear. Such results were judged as successful and supporting the appropriateness of the design solutions adopted in the BRT system. The findings did not indicate significant differences in safety performance of streets with various BRT configurations, thus, leaving space for continued use of various forms. The major safety problem is seen in pedestrian accidents at BRT junctions for which new engineering solutions are needed.

Investigating Multimodal Augmentations Contribution to Remote Control Tower Contexts for Air Traffic Management

Scipedia content — Thu, 28 Jan 2021 23:23:59 +0100

International audience; The present study aims at investigating the contribution of multimodal modalities to the context of Remote Towers. Interactive spatial sound and vibrotactile feedback were used to design 4 different types of interaction and feedback, responding to 4 typical Air Traffic Control use cases. The experiment involved 16 professional Air Traffic Controllers, who have been called to manage 4 different ATC scenarios into ecological experimental conditions. In two of the scenarios, participants had to control only one airport (i.e., Single Remote Tower context), while in the other two scenarios participants had to control simultaneously two airports (i.e., Multiple Remote Tower context). The augmentation modalities were activated or not in a balanced way. Behavioral results highlighted a significant increase in overall participants performance when the augmentation modalities were activated in Single Remote Tower context. This work demonstrates that some types of augmentation modalities can be used into Remote Tower context.

Cooling Fluids and Ambient Temperature: Sensitivity Performance of a Container Ship Organic Rankine Cycle Unit

Scipedia content — Thu, 28 Jan 2021 23:23:07 +0100

The objective of this paper is to design organic Rankine cycle units that are cooled by air or seawater and show"br" the changes in net power output and power requirement as the ambient air temperatures change both geographically"br" and seasonally. The organic Rankine cycle unit uses the available waste heat from the scavenge air system for a"br" 4,100 TEU container ship. This work uses a two-step single objective optimisation capable of selecting 14 design"br" characteristics of the organic Rankine cycle unit and with the aim of minimising the vessel’s CO2 emissions. The"br" work contributes to the study of off-design operation and different cooling fluids for marine waste heat recovery"br" systems. The results show that the organic Rankine cycle unit is more adaptable to ambient air temperatures when"br" using seawater as a cooling fluid while air is an attractive option for extremely low ambient temperatures.

Document type: Conference object

Journal of Transport and Land Use

Scipedia content — Thu, 28 Jan 2021 23:21:40 +0100

to quality public transportation is critical for employment, especially for low-income and minority populations. This study contributes to previous work on equity analyses of the U.S. public transportation system by including the 45 largest Metropolitan Statistical Areas (MSAs) in a single analysis. Year-2014 Census demographic data were combined with an existing 2014 dataset of transit job accessibility. Then, transit equality and justice indicators were developed and a regression analysis was performed to explore trends in transit job accessibility by race and income. The findings suggest that within individual MSAs, low-income populations and minorities have the highest transit job accessibility. However, the overall transit ridership is low, and in certain MSAs with high transit job accessibility both high and low income populations have high access levels but middle income populations do not. Within individual MSAs, on average, accessibility differences by income are greater than accessibility differences by race. The relative importance of race versus income for injustice increases with MSA size. In upper mid-size and large MSAs, differences by race increase. Also, the differences by race are greater among low-income populations. Accessibility- related equality and justice indicators are only one of many issues that comprise the wider discussion of equity.

GoF4R – Governance of the Interoperability Framework for Rail and Intermodal Mobility

Scipedia content — Thu, 28 Jan 2021 23:21:25 +0100

In order to promote a modal shift towards green modes of transport such as rail, the intermodality between different transport modes should be improved. The development of multimodal travel information, planning and booking services and the interoperability between business applications is currently limited due to the fragmentation and incompatibility of interchange formats and protocols both within and across transport sectors as well as within the supply chain."br" The aim of the GoF4R project is to overcome the obstacles currently impeding the development of market innovation by fostering a large acceptance of the ‘semantic web for transportation’. The establishment of good governance aims at securing the confidence of the industry to use the Interoperability Framework (IF) semantic technologies that will be established under the IP4 Innovation Programme of Shift2Rail ‘IT Solutions for Attractive Railway Services’. The objective of the Governance of the IF for Rail and Intermodal Mobility (GoF4R) project is to design a governance and management structure for the IF that will: i) create the right conditions to introduce seamless mobility services, ii) foster the development of multimodal travel services and iii) ensure its continued relevance for the future evolution of the Single European Transport Area. The governance models proposed in GoF4R will serve the interests of the European travellers by fostering the market uptake by mobility service providers. It will facilitate new business opportunities for improved mobility and travel related services and improve the incorporation of new stakeholders in the European transport arena by removing technological, administrative and economic boundaries."br" The objectives will be achieved through a partnership of specialist participants including research institutions, a major European rail operator, industry associations representing the passenger and multi-modal transport sectors and public transportation authorities. Participants, who are also involved in the consortium of designers for the IF, will focus on the establishment of sustainable governance that will promote community confidence. The governance structure will create the basis for long term stability and controlled future evolution of the IF, promoting industry confidence so that it is attractive to invest in future products and services, contributing to the achievement of a distributed semantic ‘web of transport’ integrating the TAP-TSI specifications as one of its elements.

Sustainability and shared mobility models

Scipedia content — Thu, 28 Jan 2021 23:21:08 +0100

Shared mobility or mobility in the sharing economy is characterised by the sharing of a vehicle instead of ownership, and the use of technology to connect users and providers. Based on a literature review, the following four emerging models are identified: (1) peer to peer provision with a company as a broker, providing a platform where individuals can rent their cars when not in use; (2) short term rental of vehicles managed and owned by a provider; (3) companies that own no cars themselves but sign up ordinary car owners as drivers; and (4) on demand private cars, vans, or buses, and other vehicles, such as big taxis, shared by passengers going in the same direction. The first three models can yield profits to private parties, but they do not seem to have potential to reduce congestion and CO2 emissions substantially. The fourth model, which entails individuals not only sharing a vehicle, but actually travelling together at the same time, is promising in terms of congestion and CO2 emissions reductions. It is also the least attractive to individuals, given the disbenefits in terms of waiting time, travel time, comfort, and convenience, in comparison with the private car. Potential incentives to encourage shared mobility are also discussed, and research needs are outlined.

Document type: Article

L-band Digital Aeronautical Communications System (LDACS) activities in SESAR2020

Scipedia content — Thu, 28 Jan 2021 23:15:13 +0100

traffic management communication shall transition from analog VHF voice communication to more spectrum efficient digital data communication. In Europe this transition shall be realized, among others, by the development and implementation of the L-band Digital Aeronautical Communications System (LDACS). The objective of this paper is to provide a status report on the current progress of LDACS research and development within SESAR2020. In particular, we present the objectives of SESAR2020 project "PJ.14-02-01 FCI Terrestrial Data Link", the proposed LDACS high-level architecture, the planned technical validation exercises, and the status of the ongoing LDACS standardization activities: The objective of the SESAR2020 project is to develop fully functional LDACS prototypes and to use them for validation of the air interface requirements and the support of the ATN IPS infrastructure. The LDACS architecture has been defined as a complete set of network functions needed to provide radio access to an LDACS subscriber i.e. an aircraft. LDACS standardization is currently under way in ICAO and is planned to start in EUROCAE later this year.

Identification of Relevant Aspects for Personal Air Transport System Integration in Urban Mobility Modelling

Scipedia content — Thu, 28 Jan 2021 23:13:54 +0100

This research evaluates relevant prerequisites for Personal Air Transport System (PATS) introduction into the urban transport modelling environment. Integrating Personal Air Vehicles (PAV) into existing transport systems poses various questions, which have to be thoroughly assessed. Therefore, different possible concepts of operations are being discussed, including not only ownership structure but also aspects like the adaptability of schedules (on-demand vs. scheduled services). Furthermore different demand drivers, such as job, housing, and retail location, user behaviour and mode choice are being presented with a digression on possible impacts on the city structure. In addition to that, potential cities for PAV introduction and the required properties are examined. Finally, different state-of-the-art approaches for transport modelling are constituted in order to lay the foundation for further research.

Flexible runway use modeling using pairwise RECAT-EU separation minima

Scipedia content — Thu, 28 Jan 2021 23:10:48 +0100

If we would take fuel consumption and noise annoyance into account in the runway allocation process,runway allocation can take place more efficiently, both in terms of fuel cost as well as noise annoyance. In this research, the focus is on the further development of a model in order to make the calculationsmore refined. Moreover, the improvements conducted in this research relate to the methodologies to compute the cost of the decision variables and the level of complexity of specific linear programming constraints in the optimization model. Consequently, the aim of this research is to answer the following research question: Can the performance of Standard Flex be further optimized by applying pairwise flight dependencies, while ensuring and contributing to a valid trade-off between runway capacity, noise emission, fuel burn and safety. By means of this research, the flexible runway allocation model has been improved on many aspects. The computation strategy of both objectives has moved from a reference aircraft based computation strategy to an analysis based on each unique aircraft on its own. This refined computational approach has resulted in a better understanding and modeling strategy of the operations that take place at an airport. Finally, the implementation of RECAT-EU separation minima has resulted in a reduction of 5-10% in overall separation times with respect to the regular ICAO WTC strategy, based on multiple air traffic demand mixture scenarios, based on a specific demand of flights?.

Intent-driven composition of resource-management SDN applications

Scipedia content — Thu, 28 Jan 2021 23:06:59 +0100

software-defined networking deployments mature, operators need to manage and compose multiple resource-management applications, such as traffic engineering and service chaining. Today such applications' resource management algorithms run separately and composition approaches are output-driven, e.g., running each application on a statically provisioned slice of the network and then combining the flow rules output for each slice. Such approaches result in inefficient resource utilization and unfairness. Instead, we argue for intent-driven composition, where a unified resource optimization formulation is composed from applications' high-level intents and the solution to this problem formulation is realized in the network. We design Chopin1, an intent-driven framework for composing SDN resource-management applications. Chopin's design addresses key robustness challenges with regard to efficiency and fairness that arise in realizing such an intent-driven approach. We have integrated Chopin with the ONOS controller and show that it substantially improves efficiency and fairness over existing composition approaches.

Novel common vehicle information model (CVIM) for future automotive vehicle big data marketplaces

Scipedia content — Thu, 28 Jan 2021 23:04:22 +0100

Even though connectivity services have been introduced in many of the most recent car models, access to vehicle data is currently limited due to its proprietary nature. The European project AutoMat has therefore developed an open Marketplace providing a single point of access for brand-independent vehicle data. Thereby, vehicle sensor data can be leveraged for the design and implementation of entirely new services even beyond traffic-related applications (such as hyper-local traffic forecasts). This paper presents the architecture for a Vehicle Big Data Marketplace as enabler of cross-sectorial and innovative vehicle data services. Therefore, the novel Common Vehicle Information Model (CVIM) is defined as an open and harmonized data model, allowing the aggregation of brand-independent and generic data sets. Within this work the realization of a prototype CVIM and Marketplace implementation is presented. The two use-cases of local weather prediction and road quality measurements are introduced to show the applicability of the AutoMat concept and prototype to non-automotive applications.

Opportunities for resilient rail system development using natural language processing.

Scipedia content — Thu, 28 Jan 2021 23:03:56 +0100

In this paper we examine a natural language processing and machine learning approach to help assess the quality"br" of railway hazard logs. The focus is on highlighting red flags in the hazard log content to help improve the accuracy"br" and quality of the contents and so the speed of risk reviews. Data is presented that indicate the approach has"br" potential for significant savings in time and increased quality. The tool is one of a number that we are developing"br" as part of an initiative to improve rail system development and operation by employing artificial intelligence (AI)"br" to augment existing methods in the context of a wider system engineering approach. This will in turn lead to rail"br" systems becoming more sustainable and resilient.

Evaluation of the fuel-consumption-reduction potential of a Danube vessel

Scipedia content — Thu, 28 Jan 2021 23:03:35 +0100

In the framework of the Horizon 2020 EU project PROMINENT, the fuel-consumption-reduction potential of a Danube vessel is evaluated. The vessel is sailing between Regensburg and Budapest on the Upper Danube. The results comprise sailing time and fuel consumption derived for three different constant delivered power values representing the most significant power range the vessel is being operated in, as well as 3 different speeds over ground when sailing downstream. They are evaluated for 15 characteristic sections of the Upper Danube when sailing upstream, as well as downstream. The afore-mentioned results are given for three different water levels: the Low Navigable Water Level (LNWL), an artificial Mean Water Level (MWL) and the Highest Navigable Water Level (HNWL), and they are combined to different sailing strategies comprising sailing with different constant brake powers upstream and speeds over ground downstream.

AutoAccel: Automated Accelerator Generation and Optimization with Composable, Parallel and Pipeline Architecture

Scipedia content — Thu, 28 Jan 2021 23:02:17 +0100

CPU-FPGA heterogeneous architectures are attracting ever-increasing attention in an attempt to advance computational capabilities and energy efficiency in today's datacenters. These architectures provide programmers with the ability to reprogram the FPGAs for flexible acceleration of many workloads. Nonetheless, this advantage is often overshadowed by the poor programmability of FPGAs whose programming is conventionally a RTL design practice. Although recent advances in high-level synthesis (HLS) significantly improve the FPGA programmability, it still leaves programmers facing the challenge of identifying the optimal design configuration in a tremendous design space. This paper aims to address this challenge and pave the path from software programs towards high-quality FPGA accelerators. Specifically, we first propose the composable, parallel and pipeline (CPP) microarchitecture as a template of accelerator designs. Such a well-defined template is able to support efficient accelerator designs for a broad class of computation kernels, and more importantly, drastically reduce the design space. Also, we introduce an analytical model to capture the performance and resource trade-offs among different design configurations of the CPP microarchitecture, which lays the foundation for fast design space exploration. On top of the CPP microarchitecture and its analytical model, we develop the AutoAccel framework to make the entire accelerator generation automated. AutoAccel accepts a software program as an input and performs a series of code transformations based on the result of the analytical-model-based design space exploration to construct the desired CPP microarchitecture. Our experiments show that the AutoAccel-generated accelerators outperform their corresponding software implementations by an average of 72x for a broad class of computation kernels.

Evolution into a new-generation Traffic Data Platform to support emerging interoperability and multi-modal traffic applications

Scipedia content — Thu, 28 Jan 2021 23:01:49 +0100

Traffic is getting smart, participants and infrastructure are getting connected and more data is digitally available. Different kinds of platforms were set up to support new applications and use cases: to manage traffic, to operate fleets, to influence and optimize routing, to provide essential data such as highly precise and local dynamic maps as well as to collect data about the traffic infrastructure. If traffic stakeholders and their interacting use cases incorporate, then also the data platforms should be fused to improve interoperability. The German Aerospace Center’s Institute of Transportation Systems (DLR-TS) also operates three specialized data platforms to improve emergent traffic applications and support mobility research."br" The Traffic Data Platform (TDP) provides all basic tools for storage, map-matching, processing, fusion and management of traffic data from various sensors and third party sources such as floating object data, observed data and data from sensors like induction loops or traffic eyes as well as different road networks. Additionally, information about infrastructure and exceptional events such as natural disasters are integrated."br" The Bahnserver (railway server) provides methods for centralized collection, automated processing, 3D visualization of rail network infrastructure elements as well as position-based real-time information of vehicles. It provides tools for merging and validation of different data sources in one database, plotting of units with automatic telemetry reporting and intuitive visualization of geo-referenced measurements."br" The Digital Atlas collects heterogeneous geodata about road networks and urban infrastructure to provide 3D environments and detailed topographical and topological road descriptions on lane level with high accuracy for driving simulators and advanced driver assistance and automation systems."br" These three platforms are operating in the same traffic environment and have similarities in used data and supported applications. Therefore it is obvious to fuse these platforms to make use of the best of the three worlds: DLR is migrating the Digital Atlas and the Bahnserver into TDP to extend it with their features. This supports inter-map-matching to use maps with different levels of detail from different sources, harmonized visualization services, enhance user management for fleet operators using only few maintenance units or thousands of private end-users. This paper will present the three platforms and their use cases, describe the approach of fusing the systems and give prospects about the potential of the new-generation traffic data platform.

Transport and Equity Analysis results' empowerment for future mobility challenges

Scipedia content — Thu, 28 Jan 2021 22:57:22 +0100

Transport and Equity Analysis COST Action – TU1209 dedicated a special attention to the mobility challenges related with the social and technical dimensions of transport. The three theoretical and practical results of TEA COST dealing with mobility issues are:"br" 1. Proposing a shift from a time-saving based appraisal paradigm to a new composite variable able to jointly consider personal characteristics, spatial accessibility, and trips attributes (i.e. needs of people)."br" 2. Changing the approach for analyzing users' mobility choice from a utility-based approach to a needs-based approach."br" 3. Opening transport planning to the real participation of users through adapted mobility survey, meetings for proposing and creating consensus around transport planning measures, and innovative governance tools.

Kinematics of powered two-wheelers at bends on intercity roads

Scipedia content — Thu, 28 Jan 2021 22:56:48 +0100

In France, powered two-wheelers (PTWs) account for 18% of fatal accidents, and PTW riders are 27 times more"br" likely to be killed than car drivers. More than one-third (40%) of these fatal accidents occur at bends on intercity"br" roads. Based on this observation, a prototype vehicle embodying the full range of intrinsic and extrinsic parameters"br" was developed in order to analyse rider behaviour. The Rider Behaviour Analysis Motorcycle (Moto d’Analyse du"br" Comportement du Conducteur, MACC) was used to analyse speed and lateral acceleration, capture videos and"br" measure vehicle dynamics and trajectories. The findings revealed certain practices that had never previously been"br" quantified. Alongside this behavioural study, we will also highlight some key accident research statistics associated"br" with PTWs at bends on intercity roads.

Comparing lab to field properties in CEN Type Testing for Asphalt Concrete – the NL-LAB program

Scipedia content — Thu, 28 Jan 2021 22:50:15 +0100

In 2008 Europe introduced the CEN standards for Asphalt Concrete (EN13108 series). The Netherlands adopted the approach of fundamental requirements and input target composition. The aim was to achieve a better understanding of those mechanical properties and eventually enable less prescriptive requirements for the composition while retaining well-functioning pavement materials. This was seen as a pre-requisite for innovations in pavement engineering and pavement materials."br" Some surprises in laboratory performance led to the initiation of a program using the Dutch road network as a living laboratory (NL-LAB). Using laboratory produced and field specimens, this program aims first of all to assess the effects of mixing and compaction on the fundamental properties used in the Netherlands. This paper describes the NL-LAB program and the results for the first projects that are analysed, focussing on the stiffness and resistance to permanent deformation. The results show that, although the fundamental approach indeed stimulates research into a more fundamental understanding of Asphalt Concrete, the current understanding is still far from complete. It also highlights the importance of well standardized tests and the importance of inter-laboratory studies.

Deep Learning-based Object Classification on Automotive Radar Spectra

Scipedia content — Thu, 28 Jan 2021 22:46:51 +0100

Scene understanding for automated driving requires accurate detection and classification of objects and other traffic participants. Automotive radar has shown great potential as a sensor for driver assistance systems due to its robustness to weather and light conditions, but reliable classification of object types in real time has proved to be very challenging. Here we propose a novel concept for radar-based classification, which utilizes the power of modern Deep Learning methods to learn favorable data representations and thereby replaces large parts of the traditional radar signal processing chain. We propose to apply deep Convolutional Neural Networks (CNNs) directly to regions-of-interest (ROI) in the radar spectrum and thereby achieve an accurate classification of different objects in a scene. Experiments on a real-world dataset demonstrate the ability to distinguish relevant objects from different viewpoints. We identify deep learning challenges that are specific to radar classification and introduce a set of novel mechanisms that lead to significant improvements in object classification performance compared to simpler classifiers. Our results demonstrate that Deep Learning methods can greatly augment the classification capabilities of automotive radar sensors.

Booking Processes in Autonomous Carsharing and Taxi Systems

Scipedia content — Thu, 28 Jan 2021 22:46:32 +0100

With the introduction of autonomous vehicles, ride-hailing, taxi, and carsharing might all become on-demand door-to-door mobility services. We assume that the carsharing mode will develop into a system with more flexibility for users while ride-hailing and taxi will focus on the efficiency of the system. The flexibility of the autonomous carsharing system can present itself in multiple ways, e.g. the option to drive manually, withhold the information of the final stop, freely choosing routes and stops, or reserving a vehicle for an unspecified amount of time. The more efficient autonomous taxi system requires user requests to contain the information of the destination and the operator has full control over the vehicles. We discuss some implications (vehicle-search and assignment, scaling, ridepooling and relocations) of the different systems qualitatively and show a numerical study of a small and large scale scenario reflecting the efficiency advantage of the autonomous taxi system.

Towards a risk-based approach for the design of highly resilient future vehicles

Scipedia content — Thu, 28 Jan 2021 22:43:47 +0100

Current technological trends in transportation are towards increasing levels of automation, and ultimately to fully autonomous operation, as well as greater wireless connectivity. Although cars are among the best known examples, similar trends are also found in hazardous industrial environments, as well as in the marine and aerospace sectors. However, as the role of the driver/operator is progressively removed from vehicle control, the electronic systems that replace the human inputs will need to provide extremely high levels of dependability in order to ensure the public acceptability of these technologies. Thus, the electronic systems of future vehicles, as well as the intelligent transport systems that they interact with, will need to be designed to ensure a high degree of resilience to a wide range of threats. This paper outlines the elements of a unified risk-based approach to support the development of future vehicles that are highly resilient to environmental and criminal threats, thus ensuring acceptable levels of functional safety, safety of the intended functionality, cyber security and mission-critical functionality.

Numerical modelling of acoustic pressure fields to optimize the ultrasonic cleaning technique for cylinders

Scipedia content — Thu, 28 Jan 2021 22:34:24 +0100

Fouling build up is a well-known problem in the offshore industry. Accumulation of fouling occurs in different structures, e.g. offshore pipes, ship hulls, floating production platforms. The type of fouling that accumulates is dependent on environmental conditions surrounding the structure itself. Current methods deployed for fouling removal span across hydraulic, chemical and manual, all sharing the common disadvantage of necessitating halting production for the cleaning process to commence. Conventionally, ultrasound is used in ultrasonic baths to clean a submerged component by the generation and implosion of cavitation bubbles on the fouled surface; this method is particularly used in Reverse Osmosis applications. However, this requires the submersion of the fouled structure and thus may require a halt to production. Large fouled structures such as pipelines may not be accommodated. The application of high power ultrasonics is proposed in this work as a means to remove fouling on a structure whilst in operation. The work presented in this paper consists of the development of a finite element analysis model based on successful cleaning results from a pipe fouled with calcite on the inner pipe wall. A Polytec 3D Laser Doppler Vibrometer was used in this investigation to study the fouling removal process. Results show the potential of high power ultrasonics for fouling removal in pipe structures from the wave propagation across the structure under excitation, and are used to validate a COMSOL model to determine cleaning patterns based on pressure and displacement distributions for future transducer array design and optimization.

Influence of blast-induced ground vibrations on buried transmission pipelines

Scipedia content — Thu, 28 Jan 2021 22:31:22 +0100

Upgrading of freight railways to meet operational and market demands

Scipedia content — Thu, 28 Jan 2021 22:27:04 +0100

The European objective of a modal shift of freight transports to railways will require extensive upgrading of"br" existing railway lines. This is due to the fact that very few dedicated freight railways are currently being built and"br" existing lines were built for traffic demands at the time of construction. A transition to increased and enhanced"br" railway freight operations can therefore be costly and complicated. To minimize negative effects, a guideline for"br" upgrading was developed within the Capacity4Rail project. The current paper presents the major findings from"br" this guideline. In particular, it outlines different upgrading possibilities and their implications, and details"br" structured approaches to upgrading analyses. Setting out from the Capacity4Rail handbook, the current paper"br" discusses possibilities for upgrading of substructures, bridges, tunnels, and the track structure. In these areas, an"br" overview of challenges and possibilities is presented together with examples of experience from operational"br" upgrading. The paper concludes that freight line upgrading using a more streamlined approach, as outlined in the"br" guideline, is a necessity if EU objectives on modal shifts in transportation are to be met. Further, it demonstrates"br" why a political drive is necessary to increase efforts to upgrade freight lines.

Recasting the Understanding of Habits for Behaviour-Oriented Policies in Transportation

Scipedia content — Thu, 28 Jan 2021 22:26:42 +0100

The role of habits in influencing transportation behaviour is acknowledged in many studies. However, most of these analyses draw on a narrow perspective of habits. In this paper, we adopt a reversed perspective regarding the interplay between habits and rationality. The insightfulness of this perspective is illustrated with the findings of two empirical studies on urban transportation. This paper shows that the underlying structure (i.e. the "genotype") behind the phenotypic manifestation of a habit is essential to grasp for getting a better understanding of the role played by habits in explaining car use. The framework of habitual practices is then put forward in discussing the results. Its rationale is to provide a characterisation of the interconnected elements that make and shape the transportation practices, together with important aspects regarding how they are formed and sustained over time. Adequately picturing both constituent elements as well as dynamic aspects is crucial for explaining the strength of habitual practices and thus car dependence. In doing so, the framework of habitual practices could thus well be of help for policy-makers in reflecting on the design of efficient and innovative interventions for the transition towards more sustainable transportation behaviours.

SCOPUS: ar.j

info:eu-repo/semantics/published

Document type: Article

CarSense: Evaluation of the Potential of In-Vehicle Sensor Data for Road Operators

Scipedia content — Thu, 28 Jan 2021 22:24:53 +0100

Modern vehicles are equipped with dozens of sensors collecting data for supporting automotive trends like Autonomous and/or Connected Driving. For road operators, in-vehicle data or so-called Extended Floating Car Data (XFCD) are often promised as the Holy Grail for supporting efficient road operations. In this work, we tackle the question of benefits with respect to potential in-vehicle sensor data usage from a road operator’s point of view, focusing on traffic information, traffic management and road maintenance. Key results are amongst others: (1) the need for customized XFCD solutions supporting road operator’s tasks, (2) standardized data access and formats for in-vehicle sensor data, (3) cost-effective integration of XFCD into existing monitoring infrastructure, and (4) the need to actively promote road operator’s interests.

Discussion On Density-Based Clustering Methods Applied for Automated Identification of Airspace Flows

Scipedia content — Thu, 28 Jan 2021 22:24:22 +0100

Traffic Management systems generate a huge amount of track data daily. Flight trajectories can be clustered to extract main air traffic flows by means of unsupervised machine learning techniques. A well-known methodology for unsupervised extraction of air traffic flows conducts a two-step process. The first step reduces the dimensionality of the track data, whereas the second step clusters the data based on a density-based algorithm, DBSCAN. This paper explores advancements in density-based clustering such as OPTICS or HDBSCAN*. This assessment is based on quantitative and qualitative evaluations of the clustering solutions offered by these algorithms. In addition, the paper proposes a hierarchical clustering algorithm for handling noise in this methodology. This algorithm is based on a recursive application of DBSCAN* (RDBSCAN*). The paper demonstrates the sensitivity of these algorithms to different hyper-parameters, recommending a specific setting for the main one, which is common for all methods. RDBSCAN* outperforms the other algorithms in terms of the density-based internal validity metric. Finally, the outcome of the clustering shows that the algorithm extracts main clusters of the dataset effectively, connecting outliers to these main clusters.

Document type: Conference object

Investigating which factors affect lateral position variability through a driving simulator experiment

Scipedia content — Thu, 28 Jan 2021 22:19:34 +0100

The objective of the present research is to investigate the effect of several risk factors including distraction conditions, driver as well as road environment characteristics on lateral position variability. For this purpose, a large driving simulator experiment was carried out, in which 95 participants from three different age groups were asked to drive under different types of distraction in different road and traffic conditions. To achieve the research objectives, generalized linear mixed models were implemented regarding standard deviation of lateral position as the data used in this research involve repeated observations from each individual trial (each driver completes six drives in rural and six drives in urban environment). Results indicate that several parameters are found to significantly affect lateral position variability including driver characteristics such as gender and age and area type. Regarding distraction cell phone use slightly increased lateral position variability indicating that drivers while talking and holding the cell phone find difficult to maintain the vehicle probably.

Application of the magnetic leakage field method to investigate wire strands

Scipedia content — Thu, 28 Jan 2021 22:17:06 +0100

The magnetic leakage measurement method is useful for the nondestructive investigation of the integrity of tendons used in prestressed concrete components [1, 2]. It is based on the fact that ruptures or sudden changes in the cross sections of prestressing steel can be detected by characteristic magnetic anomalies. Due to the fact that all ferromagnetic elements of the reinforcement cause magnetic signals, these anomalies have to be obtained by using a magnetization scheme adapted to the given geometrical conditions and according signal analysis. The measuring of the remanence magnetic leakage field, in combination with numerical methods, leads to the satisfactory suppression of unwanted signals from the mild reinforcement. Ruptures of prestressing steel of pretensioned concrete members can be reliably detected with good repeatability. In case of tensioning steel arranged as bundle, the detection limit becomes severely limited because the adjacent intact steels cause a considerable attenuation of the signal of a rupture."br" This paper shows different applications of the magnetic field leakage method for the investigation of wire strands.

Risk Assessment of Electrical Power Systems Considering Traffic Congestion

Scipedia content — Thu, 28 Jan 2021 22:15:05 +0100

With the increasing penetration of electric vehicles in the transportation system, more and more interactions appear between the transportation and power systems. This requires considering the impact of disturbances in the electrified transportation system onto the stability of the power system. This paper addresses this issue by proposing a method based on a cell transmission model (CTM) of the electrified transportation system and an alternative current (AC) model of the power system. Specifically, CTM is used to simulate the dynamic realtime traffic under congestion disturbances and evaluate the charging demands in the areas of the electrified transportation system. The charging demands are input to the AC model of the power system to calculate the fluctuations in power flow distributions. The proposed method can simulate the dynamic interactions between the electrified transportation system and the power system, and quantitatively measure the impacts of traffic disturbances on the stability of the power system. A numerical example is used to illustrate the proposed method.

Evaluation Methodology for Cooperative ADAS Utilizing Simulation and Experiments

Scipedia content — Thu, 28 Jan 2021 22:14:46 +0100

Wireless vehicular networks are to be deployed in both Europe and the USA within upcoming years. Such networks introduce a new promising source of information about vehicular environments to be used by cooperative advanced driver assistance systems (ADAS). However, development and evaluation of such cooperative ADAS is still challenging. Hence, we introduce a novel methodology for their development and evaluation processes. It is applied to evaluate the fulfillment of requirements on position accuracy information within exchanged messages. Such requirements are only roughly defined and not sufficiently evaluated in field tests. This holds especially for Global Navigation Satellite Systems (GNSS) optimized for maximum integrity of obtained positions. Such configuration is required to increase robustness and reliability of safety critical ADAS. We find that pure GNSS-based positioning cannot fulfill position accuracy requirements of studied ADAS in most test cases.

Optimizing Multi-class Fleet Compositions for Shared Mobility-as-a-Service

Scipedia content — Thu, 28 Jan 2021 22:10:57 +0100

Mobility-as-a-Service (MaaS) systems are transforming the way society moves. The introduction and adoption of pooled ride-sharing has revolutionized urban transit with the potential of reducing vehicle congestion, improving accessibility and flexibility of a city's transportation infrastructure. Recently developed algorithms can compute routes for vehicles in realtime for a city-scale volume of requests, as well as optimize fleet sizes for MaaS systems that allow requests to share vehicles. Nonetheless, they are not capable of reasoning about the composition of a fleet and their varying capacity classes. In this paper, we present a method to not only optimize fleet sizes, but also their multi-class composition for MaaS systems that allow requests to share vehicles. We present an algorithm to determine how many vehicles of each class and capacity are needed, where they should be initialized, and how they should be routed to service all the travel demand for a given period of time. The algorithm maximizes utilization while reducing the total number of vehicles and incorporates constraints on wait- times and travel-delays. Finally, we evaluate the effectiveness of the algorithm for multi-class fleets with pooled ride-sharing using 426,908 historical taxi requests from Manhattan and 187,243 downtown Singapore. We show fleets comprised of vehicles with smaller capacities can reduce the total travel delay by 10% in Manhattan whereas larger capacity fleets in downtown Singapore contribute to a 9% reduction in the total waiting time.

Autonomous taxi operations: algorithms for the solution of the routing problem

Scipedia content — Thu, 28 Jan 2021 22:10:11 +0100

International audience; In past decades, airport ground operations have attracted researchers, with the aim of increasing airport efficiency and reducing the environmental impact of airport operations. Airplane taxi operations have received particular attention for their significant impact on the airport efficiency and pollutant emissions and on the fuel cost for airlines. Alternative solutions have been proposed to the engine-on taxi procedures, including the employment of autonomous vehicles to tow the aircraft between gates and runways. In order to be performed, autonomous taxi procedures require precise planning and scheduling by means of sophisticated management systems. At the base of these management systems, lie algorithms for the solution of the routing problem, which provide feasible paths on the airport surface. Two different approaches can be used: compute the paths on the fly, or pre-compute all the possible paths between all the pairs of starting/ending points on the airport grid and store them in a database that is called when needed. In this paper, four different algorithms are implemented and compared for the computation of paths on the fly: two Hopfield-type neural networks and two algorithms based on graph theory. Furthermore, two algorithms for the generation of the path database are presented: a modified version of the Breadth-first search and an implementation of the k-shortest paths algorithm. Each taxi mission, performed by the tractors, consists of three different events, called phases: one central towing phase, where the tractor tows the aircraft between gate and runway and two repositioning phases in which the tractors move from its actual position to the airplane or from the airplane back to the depot.

Profiling Future Air Transport Passengers in Europe

Scipedia content — Thu, 28 Jan 2021 22:09:19 +0100

Gaining detailed insights into socio-economic characteristics and behaviour of air passengers constitutes a major benefit for stakeholders in the industry. Understanding passengers’ diverse expectations, requirements and needs can open up new revenue sources in the form of innovative products and services. Being the first mover can thus create a competitive advantage towards opponents. Market segmentation approaches help to identify key consumer groups, to design marketing strategies accordingly and maximise profits. Additionally to current passengers’ research, this paper applies an a priori technique to determine six future air passenger profiles for 2035, reflecting major developments faced by the European transport sector such as changing environmental awareness, increased use of information and communication technologies or disruptive developments like autonomous driving. Profiles enable differentiated insights into future passenger behaviour to derive implications for the transport sector.

Performance Measure of Vehicle Onboard Vision System: An Interval Observer-based Approach

Scipedia content — Thu, 28 Jan 2021 22:06:05 +0100

International audience; Advanced Driver assistance systems that assist in safe vehicle guidance require a thorough understanding of the crossed environment. Because these systems rely on the vision sensor's ability to detect road boundaries and lane marking, these systems are extremely sensitive to road conditions. Itis therefore important to take a critical look at their key aspects and evaluate their performance and accuracy. In this work, an evaluation framework to measure the performance of a vehicle onboard stereo-vision system using set-membership theory is presented. The proposed approach considers the changes that might occur in vehicle dynamics during the maneuver. The experiment design and evaluation of the proposed method is shown using field data acquired using an instrumented vehicle.

Linking Multimodal Traveller Information Services for Transnational Journey Planning

Scipedia content — Thu, 28 Jan 2021 22:02:42 +0100

There is a huge cross-border travel demand within the EU leading to hundred millions of cross-border trips every year. Notwithstanding the information demand for seamless journey planning and accurate and timely information on public transport, the provided traveller information is often limited in terms of the provided modes and in terms of its geographical coverage. The above mentioned deficiency is tackled by an international consortium of journey planner- and transport operators in the frame of the INTERREG project “LinkingDanube”. The goal is the brining information together from several existing regional services in order to enable journey planning that goes beyond the territory covered by the single systems and offers travellers seamless travel information provided in one integrated journey plan. In particular the objective is to develop a system architecture that enables that combination of services, which is addressed as “distributed journey planning” and an integration of the results. By developing and establishing a common interface (Open API) at each of the involved systems, the exchange of requests and results (not data) will be facilitated. The paper elaborates the service architecture and outlines the technical implementation.

The methodology of increasing the functional safety of aviation enterprises

Scipedia content — Thu, 28 Jan 2021 21:57:42 +0100

Functional safety of aviation enterprises (control towers and airports) depends significantly on the state of the system "Aviation Security Service — entities that commit acts of unlawful interference in the operation of airports" and the functional condition of the Aviation Security Service staff and air traffic controllers. Therefore, its increase can be achieved only with the systematic application of organizational measures and measures aimed at reducing the human factor's impact on the effectiveness of the Aviation Security Service staff and air traffic controllers. The article describes the methodology for improving the operational safety of the aviation enterprise, based on the developed models and the methods for managing the levels of the state of the system, employees of the Aviation Security Service and air traffic controllers.

Exploiting Map Topology Knowledge for Context-Predictive Multi-Interface Car-to-Cloud Communication

Scipedia content — Thu, 28 Jan 2021 21:56:35 +0100

While the automotive industry is currently facing a contest among different communication technologies and paradigms about predominance in the connected vehicles sector, the diversity of the various application requirements makes it unlikely that a single technology will be able to fulfill all given demands. Instead, the joint usage of multiple communication technologies seems to be a promising candidate that allows benefiting from characteristical strengths (e.g., using low latency direct communication for safety-related messaging). Consequently, dynamic network interface selection has become a field of scientific interest. In this paper, we present a cross-layer approach for context-aware transmission of vehicular sensor data that exploits mobility control knowledge for scheduling the transmission time with respect to the anticipated channel conditions for the corresponding communication technology. The proposed multi-interface transmission scheme is evaluated in a comprehensive simulation study, where it is able to achieve significant improvements in data rate and reliability.

High efficient natural gas engine concepts for long haul transportation

Scipedia content — Thu, 28 Jan 2021 21:56:13 +0100

Different natural gas engine technologies can be applied for commercial vehicles and those investigated in the HDGAS project are:"br" - Positive ignition natural gas engine with direct injection"br" - Dual fuel natural gas engine (premixed gas and pilot diesel injection)"br" - High pressure gas injection with pilot diesel injection"br" This paper will describe the challenges and solutions of the different engine concepts in combination with LNG tank systems in respect of"br" - Greenhouse gas reduction potential including measures to improve gas engine efficiency"br" - Emission compliance to EU VI

Social innovations for transitioning towards sustainable mobility

Scipedia content — Thu, 28 Jan 2021 21:55:35 +0100

Mobility is a basic need human need, fostering personal interrelations and exchange of good. Growing mobility"br" also bears negative side effects and costs increase. In search for new mobility solutions, technological innovations"br" play a key role when it comes to electric mobility or automated driving. For a successful mobility transition, new"br" spaces for innovative forms and models of sustainable and inclusive mobility services are emerging based on"br" transition thinking. This paper aims to contribute to a better understanding of the scope and impact of social"br" innovations for sustainable and inclusive mobility by providing empirical evidence for shared mobility solutions"br" in rural areas in Austria. It provides evidence for the power of social innovations driven by civic engagement to"br" create local ‘niches’ and also points out limits for scaling towards systemic change.

The Dialogue Workshop, a Method to Analyse the Coordination Needs Between Heterogenous Stakeholders for Risk Prevention in Micro and Small Enterprises (MSEs)

Scipedia content — Thu, 28 Jan 2021 21:54:46 +0100

The aim is to describe the coordination conditions between OSH advisors and professional organisations in order to develop good practices in risk prevention in MSEs. Owner-managers of MSEs often have difficulties in applying OSH legislation and a lack of time and skills for doing it. The stakeholders’ coordination develops a prevention program in two case studies conducted in both the road transport and construction sectors. Discussion groups were conducted during a one-day dialogue workshop with different stakeholders (OSH regulators, OSH advisors, professional organisations, worker and employer representations) of these programs. The cooperation between professional organisations and OSH advisors seems necessary to develop a proactive approach and to create a specific program, considering the particular needs of the professional branch.

Modelling range extension of electric vehicles using dynamic wireless power transfer

Scipedia content — Thu, 28 Jan 2021 21:54:31 +0100

The limited range of electric vehicles (EVs) is frequently quoted as one of the main impediments to their widespread adoption. One promising technological solution to this is Dynamic Wireless Power Transfer (DWPT) whereby coils within the road surface transfer energy to moving vehicles (providing motive power or charging on-board batteries). This paper reviews what has been suggested as an acceptable range for an EV and then uses published data on DWPT performance to develop a model for estimating how much of a road network needs to be equipped with DWPT technology to satisfy specific range requirements. In one typical “long journey” scenario, approximately 66% of the network would need to be equipped. Other scenarios are presented and sensitivity analysis of the model’s key parameters is explored. Finally, a series of recommendations are made for optimising DWPT provision.

Using Grouped Linear Prediction and Accelerated Reinforcement Learning for Online Content Caching

Scipedia content — Thu, 28 Jan 2021 21:53:18 +0100

Proactive caching is an effective way to alleviate peak-hour traffic congestion by prefetching popular contents at the wireless network edge. To maximize the caching efficiency requires the knowledge of content popularity profile, which however is often unavailable in advance. In this paper, we first propose a new linear prediction model, named grouped linear model (GLM) to estimate the future content requests based on historical data. Unlike many existing works that assumed the static content popularity profile, our model can adapt to the temporal variation of the content popularity in practical systems due to the arrival of new contents and dynamics of user preference. Based on the predicted content requests, we then propose a reinforcement learning approach with model-free acceleration (RLMA) for online cache replacement by taking into account both the cache hits and replacement cost. This approach accelerates the learning process in non-stationary environment by generating imaginary samples for Q-value updates. Numerical results based on real-world traces show that the proposed prediction and learning based online caching policy outperform all considered existing schemes.

Comment: 6 pages, 4 figures, ICC 2018 worksho

Optimal Day-Ahead Energy and Reserve Bidding Strategy of a Risk-Averse Electric Vehicle Aggregator in the Nordic Market

Scipedia content — Thu, 28 Jan 2021 21:52:33 +0100

Electric vehicles (EV) can be considered as energy storage with availability, energy and capacity constraints that can provide flexibility to the power system in the form of balancing products when aggregated. In this paper, we develop a two-stage stochastic optimization problem that maximizes the profit of a risk-averse EV aggregator for bids on the day ahead in both energy and Frequency Containment Reserve (FCR) markets. Unidirectional charging is examined, while we take into account uncertainty from prices and vehicle availability. Case studies are carried out in different Nordic bidding areas based on historical EV charging data. We identify a strong temporal alignment of EV availability and high FCR-N prices. Results show that consumption is shifted largely towards early hours of the morning. When compared to a reference cost of charging case, up to 50% of the cost of charging can be recovered in Norway, and 100% in Sweden. "p"QC 20190710. QC 20191203

Multi-objective fuzzy rule-based prediction and uncertainty quantification of aircraft taxi time

Scipedia content — Thu, 28 Jan 2021 21:49:34 +0100

The ever growing air traffic demand and highly connected air transportation networks put considerable pressure for the sector to optimise air traffic management (ATM) related performances and develop robust ATM systems. Recent efforts made in accurate aircraft taxi time prediction have shown significant advancement in generating more efficient taxi routes and schedules, benefiting other key airside operations, such as runway sequencing and gate assignment. However, little study has been devoted to quantification of uncertainty associated with taxiing aircraft. Routes and schedules generated based on deterministic and accurate taxi time prediction for an aircraft may not be resilient under uncertainties due to factors such as varying weather conditions, operational scenarios and pilot behaviours, impairing system-wide performance as taxi delays can propagate throughout the network. Therefore, the primary aim of this paper is to utilise multi-objective fuzzy rule-based systems to better quantify such uncertainties based on historic aircraft taxiing data. Preliminary results reveals that the proposed approach can capture uncertainty in a more informative way, and hence represents a promising tool to further develop robust taxi planning to reduce delays due to uncertain taxi times.

THE IMPLICATION OF AIRLINES DEREGULATION IN THE END OF THE 20TH CENTURY ON INDUSTRIAL DEVELOPMENT OF COMMERCIAL AIR TRANSPORT SCHEDULE IN INDONESIA

Scipedia content — Thu, 28 Jan 2021 21:48:46 +0100

Automated Data-Driven Prediction on Aircraft Estimated Time of Arrival

Scipedia content — Thu, 28 Jan 2021 21:45:42 +0100

This paper is an extension of work originally reported in SESAR Innovation Days 2018 : Zhengyi Wang, Man Liang, Daniel Delahaye. Automated Data-Driven Prediction on Aircraft Estimated Time of Arrival. SID 2018, 8th Sesar Innovations Days, Dec 2018, Salzburg, Austria. ⟨hal-01944608⟩; International audience; 4D trajectory prediction is the core element of the future air transportation system. It aims to improve the operational ability and the predictability of air traffic. In this paper, a novel automated data-driven framework to deal with the prediction of Estimated Time of Arrival (ETA) on the runway at the entry point of Terminal Manoeuvring Area (TMA) is introduced. The proposed framework mainly consists of data preprocessing and machine learning models. Firstly, the dataset is divided, analyzed, cleaned, and estimated. Then, the flights are clustered into partitions according to different runway-in-use (QFU). Several candidate machine learning models are trained and selected on the corresponding dataset of each QFU. Feature engineering is conducted to transform raw data into features. After that, the experiments are performed on real ADS-B data in Beijing TMA with nested cross validation. By comparing the prediction performance on the preprocessed and un-preprocessed datasets, the results demonstrate that the proposed data preprocessing is able to improve the data quality. It is also robust to outliers, missing data, and noise. Finally, an ensemble learning strategy named stacking is introduced. Compared to other individual models, the stacked model has a more complex structure and performs best in ETA prediction. This fact reveals that the framework proposed in this study could make accurate and reliable ETA predictions.

Mapping-based solutions for an improved accessibility in SNCF railway stations

Scipedia content — Thu, 28 Jan 2021 21:45:08 +0100

Whilst crossing a railway station to take a train seems rather easy for most people, it can be an obstacle course for a lot, in particular for older and disabled people: How to avoid escalators and how to reach the right train carriage when being blind? How to find the nearest working lift when being in a wheelchair? How to avoid stairs when getting around on crutches?"br" Improving passenger’s navigation in railway stations and building accessibility services need map databases which include accessibility-related information."br" In this paper, SNCF surveys results on passengers’ needs are shown in the first place. Then, pros and cons of different semantic enrichment approaches of spatial databases are discussed, before introducing current SNCF innovative projects using these databases. Conclusively, lessons learned from tests conducted by SNCF with targeted customers’ panels are presented.

“UNFORTUNATELY, I USE MY CAR”: COMMUTER TRANSPORT CHOICES IN BRISTOL, UK

Scipedia content — Thu, 28 Jan 2021 21:44:47 +0100

© 2018 WIT Press. The leading source of nitrogen dioxide (NO2) concentrations in Bristol, United Kingdom is road transport, and Bristol exceeds the annual mean national air quality objective of 40 µg/m3 for NO2 in many locations around the city. Understanding the reasons for residents' modal choice is an important element in managing air quality in the city. The ClairCity Project approach provides insight into how to reduce overall transport demand and identify incentives that will be effective in creating modal switch away from higher polluting private motorised vehicles. From the ClairCity Project survey subset of commuters (n=442), 45% of respondents used cars or vans at least occasionally for their journey to work, with 28% of the total number of commuters relying exclusively on private motorised transport. The majority of these car users (65.6%) said they would prefer not to travel by car to work in the future. Their responses showed a mix of negative perceptions of public transport, geography and health as key motivations. Family responsibilities, lack of safe cycling and walking spaces, poor health and disability, distance, requirements to transport goods as well as themselves and the need for flexibility were all given as barriers to modal switching. This suggests that for car commuters, well-targeted policy interventions could provide practical alternatives that would appeal to those who currently rely on private motorised transport. Understanding citizens' perceptions, behaviours and activities is a key element in decision-making to reduce transport related air quality emissions and concentrations.

Energy Consumption Optimization and Vehicle Dynamics Performance Improvement for a Scalable P-HEV e-AWD Power Split Architecture to be Validated on a B-Segment Vehicle

Scipedia content — Thu, 28 Jan 2021 21:41:29 +0100

In this paper, a novel high level control-management strategy and architecture for plug-in hybrid complex hybrid vehicles energy consumption optimization and vehicle dynamics improvements is presented. A virtual Hardware in the Loop strategy is used for Vehicle Framework modelling, ensuring a high fidelity forward vehicle model. The propulsion architecture consists of a combination of two electric motor based e-drives and one Internal Combustion Engine (ICE). One e-motor is coupled with the ICE at the front axle by means of a modified belt system while the other one powers the rear axle through an integrated single speed transmission with disconnect. This architecture allows multiple operation modes: combinations of serial/parallel/split hybridization and full electric, providing e-4WD capability. Hybrid control strategies combining heuristic methods and optimization techniques are proposed to manage the power distribution between the Internal Combustion Engine and the electrical machine. In addition, an electronic horizon consisting of a smart energy management algorithm to enable predictive control hybrid strategies is presented. This uses information from vehicle sensors together with web services to extract information like traffic, weather, route inclination etc. All the information is used a-priori to optimize the energy management by using the best hybrid powertrain strategy and/or control large power electrical loads.

Thermal runaway and battery fire: comparison of Li-ion, Ni-MH and sealed lead-acid batteries

Scipedia content — Thu, 28 Jan 2021 21:38:29 +0100

Rechargeable batteries are a key component for sustainable mobility. The last years showed a significant reduction of price and increase in energy density of Li-ion batteries for electric vehicles. Unfortunately, batteries with high energy density can be source of hazard. Recently, burning Li-ion batteries of mobile-phones got a lot of negative attention in the media."br" In the first part of the paper we review the hazards of conventional Ni-MH and sealed lead-acid batteries. In the second part we focus on Li-ion batteries: we introduce different cell geometries and electrode types, we show a test-stand designed to measure thermal runaway characteristics in our laboratory and finally we conclude with results of a real thermal runaway experiment.

Greenhouse Gas Reduction and Fair Gain Sharing in Trusted Collaborative Transport Networks

Scipedia content — Thu, 28 Jan 2021 21:38:05 +0100

We present the application of market-driven methodologies developed within the EU-funded NexTrust project to"br" reduce greenhouse gases in logistics through horizontal supply chain collaboration by building trusted networks."br" In this paper, we report how we measure the reduction in Greenhouse Gas (GHG) emissions with a uniform and"br" globally endorsed GHG calculation methodology, recently proposed by the Global Logistics Emission Council"br" (GLEC), in order to increase market acceptance of emission calculation guidelines at collaborative parties. To"br" the best of our knowledge, we are among the first to apply and test the recently proposed GLEC framework to"br" assess GHG emissions in a real-life collaborative trusted setting. At the same time we set the baseline for future"br" fair gain sharing calculations. A linear allocation methodology is proposed to share the gains in GHG emissions"br" driven by the each company’s stand-alone performance. Our methodology takes into account previous synergies"br" and efficiencies as well as contribution to the network, while guaranteeing each individual partner’s fair share of"br" the gain.

A passenger flow oriented security and safety approach in international railway stations

Scipedia content — Thu, 28 Jan 2021 21:37:12 +0100

TRA 2018, 7th Transport Research Arena, Vienne, AUTRICHE, 16-/04/2018 - 19/04/2018; In the context of the Franco-German research project Re(h)strain, this work focuses on a global system analysis integrating both safety and security analysis of international and/or urban railway stations. The Re(h)strain project focuses on terrorist attacks on high speed train systems and investigates prevention and mitigation measures to reduce the overall vulnerability and strengthen the system resilience. One main criterion regarding public transport issues is the number of passengers. For example, the railway station of Paris 'Gare du Nord' deals with a bigger number of passengers than the biggest airport in the world (SNCF open Data 2014), the Atlanta airport, but in terms of passengers, it is only around the 23rd rank railway station in the world. Due to the enormous mass of people, this leads to the system approach of breaking out the station into several classes of zones, e.g. entrance, main hall, quays, trains, etc. All classes are analysed considering state-of-the-art parameters, like targets attractiveness, feasibility of attack, possible damage, possible mitigation and defences. Then, safety incidence of security defence is discussed in order to refine security requirement with regard to the considered zone. Finally, global requirements of security defence correlated to the corresponding class of zones are proposed. A case study based on the works in Re(h)strain is used as an illustration to demonstrate how the above-mentioned security and safety requirements may be implemented and handled at train stations. Therefore, the different security measures proposed for an unaffected flow of passengers are correlated to existing ones, such as video surveillance and security personal patrolling. The results of sensor set-ups realised within the project and tested in real environment show new ways of implementing innovative techniques to security applications. Depending on the technology, sensor portals at the entrances of train stations or sensor nodes distributed throughout the station increase the level of protection achievable for the detection of threats as part of preventive security concepts. The fusion of data gained by different sensor systems, including person-tracking by non-visual object recognition and trailing, enables a core function of a security assistance system. This assistance system makes security personnel aware of threats and the location of possible carriers of suspicious material as a prior condition to successful intervention measures. The high level of automation reduces human intervention to a minimum. In the conclusion it will be recommended to think of international railway stations as complex interconnected systems which are made for sharing traffic flows. It means that thinking about local solutions may produce safety problems to connected zones due to possible overcrowding.

Document type: Conference object

Road riding hazardous situations for motorcycles

Scipedia content — Thu, 28 Jan 2021 21:36:27 +0100

TRA 2018, 7th Transport Research Arena, Vienne, AUTRICHE, 16-/04/2018 - 19/04/2018; The decrease of road accidents these recent years has induced the interest to work on road driving hazardous situations called incidents. Otherwise, in France, users of Power Two-Wheeler (PTW) are less than 2% of traffic but, in the accidents represent 43% of serious injuries and 23% of killed persons. This paper provides a descriptive analysis of the incident database acquired during one year with a fleet of 30 motorcycles and a few cars equipped with an Event Data Recorder. The objective is to acquire knowledge on their accident mechanisms and improve their safety. For the 395 motorbikes' and 32 cars' incidents collected, the analysis of the triggering criteria, the dynamics parameters and the road configurations illustrates the great variety of situations and shows how the behaviours of riders are different from those of car drivers. The investigations on the causes of the incidents indicate that the more frequent cause is the driver (94%), but the road environment and the other road users could have been involved in 40% of the cases each.; La baisse du nombre d'accidents de la route de ces dernières années a amené les chercheurs à s'intéresser aux situations de conduite critiques que l'on appelle des incidents. Par ailleurs, en France, les usagers de deux roues motorisés représentent moins de 2% du trafic, et pourtant 43% des blessés graves et 23% des décès sur la route. Ce papier propose une analyse descriptive de la base de données des incidents recueillis pendant un an sur une flotte de 30 motos et quelques voitures équipées d'enregistreur de données de la route. L'objectif était d'acquérir des connaissances sur leurs mécanismes d'accident et d'améliorer leur sécurité. Pour les 395 incidents de 2-roues et les 32 incidents de voitures, l'analyse des critères de déclenchement, des paramètres de la dynamique du véhicule et des configurations de la route illustre la grande variété des situations et montre les différences de comportement des motards par rapport aux automobilistes. Les investigations sur les causes des incidents indiquent que la cause la plus fréquente est liée au conducteur, mais l'environnement et les autres usagers pourraient être impliqués dans 40% des cas.

An Open Data Taxonomy for Support Rail Asset Management

Scipedia content — Thu, 28 Jan 2021 21:30:32 +0100

The paper will provide a taxonomy of freely available European open data types and sources that are potentially related to support asset management activities which aim at improving the global safety of railway networks. The taxonomy was developed exploring available data sources within several European countries and generalizing different major categories of data that is available. Specifically, the taxonomy organizes the available open data sources into the domains of transport, energy, disaster, industry, natural resources, environment, administrative, climate, and demography. Each of these categories contain different branches of sub-categories ending in leave nodes representing specific types of data sets available openly within European jurisdictions. The taxonomy forms the first step in developing a linked open data information management system for the GoSafe Shift2Rail project. In combination with the closed information available at network managers this information management system can then be used as input for probabilistic risk assessment and the risk based ranking of assets that will be provided by GoSafe's Network Decision Support Tool.

Emissions Race SSS vs. ROAD - Road versus Short Sea Shipping (SSS): updating the 2008 comparison of emissions between modes

Scipedia content — Thu, 28 Jan 2021 21:30:10 +0100

In 2008, we compared emissions from road transport and SSS on specific routes in Vanherle (2010). The comparison of the three case studies showed how performance can differ depending on case specificities (ship type/size, route length,…), but also in what way performance was similar regardless of the differences of the 3 cases. We concluded SSS performed better than road transport in terms of CO2 and vice versa for SO2 and PM. In the past 8 years, various policies have come into effect to further reduce emissions from both modes. We find that on CO2 both road and SSS have slightly improved performance in 2016 compared to 2008. Both modes have reduced emissions of other pollutants in 2016 compared to 2008; the improvement in SSS is significantly larger than road with dramatic improvements for SO2 (up to factor 20 better), PM (up to factor 10 better) and NOx (factor 3-4 better). SSS now scores better than road transport in terms of CO2 emissions, equally well in terms of NOx and PM emissions, and worse in terms of SO2 emissions.

Estimation of Driver's Risk Awareness from Physiological Data for Smart Assistance Systems

Scipedia content — Thu, 28 Jan 2021 21:27:50 +0100

utomated and semi-automated maneuvering will have to be monitored by the driver. To fulfil this task, the driver needs to have adequate risk awareness, which should represent the actual risk of the maneuver within the traffic situation. This work aims at deriving a model of driver’s risk awareness from physiological measurements and traffic context, which were acquired from simulator experiments. Given these prerequisites, a Bayesian Network may be postulated and trained with the data to estimate the risk awareness as internal driver’s state. The results of our study show the general feasibility of our approach. Future assistance systems may take this information and adapt to the user’s risk awareness accordingly.

The use of non intrusive monitoring for slope stability assessments

Scipedia content — Thu, 28 Jan 2021 21:26:39 +0100

In the last decades frequent abrupt changes of weather conditions have been increasingly causing failures on the transport infrastructure network. These failures can take many forms with toppling of rock slopes and rainfall induced landslides in slopes being the most common form of failure. This paper presents the use of remote monitoring system by unmanned aerial vehicle (UAV) for slope stability assessment."br" Traditional mapping methods, usually based on visual assessments and personnel walking along the line being examined, can oversee important information, such as land use changes at the crest, the condition of drains and presence of cracks etc., while also exposed to very risky situations in the case of high or steep slopes. Information collected about the volume, cross-sections, contours and other parameters needed in the rock fall or landslide engineering analysis, can be modified, improved, and even completely replaced, by means of UAVs, or so called drones. Drones fitted with high-resolution cameras are enabling a more detailed inspection to be carried out, in order to remotely monitor the condition of a soil or rock slopes."br" The possibility of using drones for evaluating condition of the transport infrastructure network, with an emphasis on their advantages and disadvantages, is presented in the paper. The paper discussed demonstration sites in Croatia that have been used for the evaluation of the technique, together with the implementation of geophysical and geotechnical investigations of open tracks. Software developed at University of Zagreb, is using transformed digital data (3D orthographic images of the slopes) for the stability analysis and for the quantitative hazard assessment.

Rheological properties of materials used in bridge asphalt pavement structures

Scipedia content — Thu, 28 Jan 2021 21:23:58 +0100

One of the elements that determine the durability of bridge structures is the bridge pavement. The durability of"br" bridge pavements depends on two main factors: traffic load and climatic conditions. Bridge deck surfaces might"br" exceptionally become exposed to extreme low and high temperature conditions. Stresses and strains in this type"br" of construction are different from those of the road surfaces located on the soil. Bituminous binders and asphalt"br" mixtures are thermoplastic components of waterproofing layers and surfacing. Their properties vary depending on"br" the temperature. This paper presents the laboratory test results of rheological properties of asphalt mixtures for"br" bridge pavements. The research plan included typically used asphalt mixtures - asphalt concrete (AC), stone mastic"br" asphalt (SMA) and mastic asphalt (MA). A new type of mixtures, stone mastic asphalt with high grit content SMAMA,"br" were also tested. Paper presents test procedure for determining the stiffness of asphalt mixtures on cylindrical"br" samples. Samples preparation and test method of direct tension–compression on cylindrical specimens (DTC-CY)"br" were discussed. The selected results of dynamic modulus and phase angle at different temperatures and varied"br" frequencies were presented. These parameters describe the visco-elastic properties which determine the durability"br" of bridge pavements. The results were presented as a leading curves, black curves and Cole-Cole graphs. A"br" comparison of the results of asphalt mixtures with the results of binder in dynamic shear rheometer DSR was"br" performed. The functional evaluation of the asphalt mixtures was extended for fatigue life test and rutting"br" resistance. The results of conducted research proved that the types of asphalt mixture affect the viscoelastic"br" properties and durability of bridge pavements.

Rail freight automation in Shift2Rail – Development of prototypes

Scipedia content — Thu, 28 Jan 2021 21:23:39 +0100

The Shift2Rail pillar “Technologies for attractive and sustainable European Freight” (IP5) has a clear target"br" vision, which can be summarized in two words: Digitization & Automation. The IP5 members want to speed up"br" the digital transformation and automation of rail freight to ultimately gain market share in the competitive race"br" with other modes of transport. In order to advance automation, multiple projects have been launched under"br" funding. Two key technology demonstrators are presented in this paper:"br" 1. Semi-Automated Operation with Distributed Power Systems (DPS) for efficient Master-Slave"br" Operation, e.g. push-pull operation or in long and heavy trains up to 1,500 m"br" 2. Automatic Train Operation (ATO) with Obstacle Detection (OD) on network sections with European"br" Train Control System (ETCS) from Level 2 upward

HelyOS - Highly Efficient Online Yard Operating System

Scipedia content — Thu, 28 Jan 2021 21:23:06 +0100

The paper introduces a new control centre software approach for gated areas, called helyOS. This software is currently developed in different projects. Its first-time application is the fully automated, electrically driven AutoTruck. After a general introduction of the application domain the paper describes the AutoTruck vehicle, the architecture as well as capabilities and features of helyOS and introduces an exemplary user interface for distribution centres.

Traffic Management as a Service

Scipedia content — Thu, 28 Jan 2021 21:22:50 +0100

This paper presents Traffic Management as a Service (TMaaS), a neutral traffic management framework for urban mobility aimed at small and medium-sized cities. It accepts and connects multimodal data and services from different parties for monitoring, analysis and management and allows flexible adaptation and on-demand use of the system. TMaaS is an open urban traffic management marketplace that enables third parties to generate innovative solutions and business models and encourages citizen participation and co-creation in urban mobility. TMaaS is currently being demonstrated in real-use cases for the City of Ghent, a medium-sized city in Belgium. Selected replicator cities will be included in 2020.

First Demonstration of Single-Mode MCF Transport Network with Crosstalk-Aware In-Service Optical Channel Control

Scipedia content — Thu, 28 Jan 2021 21:21:29 +0100

We demonstrate the first crosstalk-aware traffic engineering as a use case in a multicore fibre transport network. With the help of a software-defined network controller, modulation format and channel route are adaptively changed using programmable devices with XT monitors.

Robust control of railway traction electric drive systems in terms of energy efficiency

Scipedia content — Thu, 28 Jan 2021 21:15:35 +0100

In this study, firstly, the model of railway traction electric drive systems is derived analytically along with the indirect vector control approach. In such systems, there are several disturbance and uncertainty sources like varying total weight, weight distribution, environmental conditions, voltage irregularities etc. Furthermore, resistive forces that is based on curve and grade topology, tunnel effects, velocity and aerodynamics of trains directly affects the motion control problem. In order to overcome such difficulties, a new robust pole placement approach is proposed for the speed control of such systems considering the total resistive forces, the possible uncertainties that may occur. The proposed approach is based on affine linear polynomials and D-stability. A conversion is also possible from PID type controllers to PI-PD cascade controller structure in order to eliminate the effects of undesired open loop zeros. Using the proposed approach, it becomes possible to guarantee certain predetermined performance criteria corresponding to a robust performance with energy efficiency. Additionally, correctness and effectiveness of the derived theoretical results are verified via a case study.

Assessing the robustness of Dutch Inland Ports

Scipedia content — Thu, 28 Jan 2021 21:14:22 +0100

In the present turbulent environment highlighted by energy transition, disruptive technology, and climate change impacts, adaptability and robustness are essential in long-term planning of infrastructures. This also applies to inland ports, which play an important role in the Dutch transport system. Inland ports have three major functions, i.e., transfer of goods, storage of goods, and eventually, facilitating (industrial) production of goods. A well-functioning inland port can contribute to efficient supply chains by offering multi-modal capabilities and value-added services, and importantly, contribute to a modal shift from road to environmentally friendly inland shipping.

ST4RT – Semantic Transformations for Rail Transportation

Scipedia content — Thu, 28 Jan 2021 21:13:42 +0100

The lack of interoperability between different transport modes is a barrier to the modal shift towards green modes of transport such as rail, on its own or as a backbone of an integrated mobility system, as well as the deployment of a Single European Transport Area. The ST4RT (Semantic Transformations for Rail Transportation) project aims at developing a demonstrator for a component that allows services relying on different standards to interoperate. This is achieved through the implementation of techniques for the automated transformation of messages across standards which are based on semantically-rich data. This paper presents some of the results achieved by the ST4RT project, and delineates its forthcoming contributions. ST4RT will contribute components to the Interoperability Framework which is at the core of the fourth Innovation Programme (IP4) of Shift2Rail.

Operationalizing risk-based decision support to improve the management of transport infrastructure networks

Scipedia content — Thu, 28 Jan 2021 21:13:10 +0100

vities performed through the life-cycle of a transport infrastructure may be negatively affected by a"br" substantial number of different risks. These risks may dramatically increase costs and cause significant delays"br" while negatively affecting the quality of services provided and overall efficiency. This paper introduces riskbased"br" approaches and solutions to enable, from an operational point of view, decision support in various aspects"br" and topics during the whole life-cycle of an infrastructure project, from design to operation and maintenance"br" stages. The main objective of this work is to provide a specific Operational Risk Strategy (ORS), to be"br" implemented in a specific risk-based tool, able to optimize how the Infrastructure Managers (IMs) and Operators"br" (IOs) manage the network and to guarantee them the adequate knowledge and resources to timely and effectively"br" react to potential risks that might arise. Implementing the proposed ORS will definitely result in a better"br" management of the available resources, towards a safer, more resilient and more productive Transport"br" Infrastructure (TI) network.

Risk analysis of gas distribution pipelines in apartments using the event tree analysis method

Scipedia content — Thu, 28 Jan 2021 21:10:42 +0100

During operation of gas pipelines hazards are found that can lead to failure of pipelines, including of gas distribution networks in apartments. However, research on risk analysis of gas distribution pipelines in apartments has not been widely reported. The present study represented a step toward filling in that gap; its purpose was to analyze risks in gas distribution pipelines in apartment scenario using event tree analysis method. Risk factors for gas distribution pipelines are expressed in terms of consequences and probabilities. Event tree analysis involves, first, identifying scenarios, then identifying pivotal events, constructing an event tree diagram, obtaining event failure rates and calculating risk probability. Risk level is rated as negligible, tolerable or intolerable. Results of this study show that all observed risk levels are intolerable. Even in a small-scale leakage scenario, it is likely to result in fire and severe casualties with probability value 2.6x10−3. In order to reduce the risk, gas detectors and heat/smoke detectors should be used in apartments.During operation of gas pipelines hazards are found that can lead to failure of pipelines, including of gas distribution networks in apartments. However, research on risk analysis of gas distribution pipelines in apartments has not been widely reported. The present study represented a step toward filling in that gap; its purpose was to analyze risks in gas distribution pipelines in apartment scenario using event tree analysis method. Risk factors for gas distribution pipelines are expressed in terms of consequences and probabilities. Event tree analysis involves, first, identifying scenarios, then identifying pivotal events, constructing an event tree diagram, obtaining event failure rates and calculating risk probability. Risk level is rated as negligible, tolerable or intolerable. Results of this study show that all observed risk levels are intolerable. Even in a small-scale leakage scenario, it is likely to result in fire and severe casualties with probability value 2.6x10−3. In order to reduce the ris...

Ticket sharing – a model for a sharing tariff in public transport

Scipedia content — Thu, 28 Jan 2021 21:06:51 +0100

out 85% of the daily trips start or end at home. The decision to go by foot, bicycle or car, or to travel by public transport is reached at the residence and depends on the housing situation. Sharing offers for cars and bicycles have proved to be successful in traffic management. However, it doesn’t matter yet for public transport. For this reason, so called ticket sharing was developed as a model for a better connection of housing and public transport. Residents from a housing area are provided with transferable season tickets that can be borrowed as required and are shared with all users. The developed ticket sharing model is implemented in a pilot project in the “Lincoln-Siedlung” in Darmstadt (Germany). At first, the specific conditions of the housing area and public transport were investigated. Furthermore, the tenants were interviewed about their attitudes towards public transport as well as their mobility needs. Important factors like pricing, number of required tickets etc. were fixed with the results.

Analytical Approach to Determining Factors that Influence Wheelchair Occupant Kinematics during a Railway Vehicle Crash

Scipedia content — Thu, 28 Jan 2021 21:06:36 +0100

Design-for-accessibility is becoming a global requirement. While much has been done to achieve high levels of accessibility in rail transportation, not much has been done to improve the safety of these vulnerable users in the event of heavy braking and, in a worse case, crash. The kinematics that ensues after the crash governs the secondary collision characteristics, injury mechanism and ultimately injury severity. Fundamental analytical understanding of the factors that influence crash occupant motion is required to ensure kinematics that has reasonable accuracy. This is key in providing well informed and accurate input data and establishing realistic boundary condition; particularly when commercial software is applied like a ‘black box’ without delving into the fundamental dynamics behaviour. The general wheelchair occupant kinematic model presented in this paper is initially based on the ideal condition for safety as applied in road vehicles. The data and information obtained from the model equations are, however, invaluable to providing input data and boundary conditions that result in more realistic commercial software FE model results.

Development of a Climate Adaptation Strategy for the InnovA58 highway in the Netherlands

Scipedia content — Thu, 28 Jan 2021 21:06:17 +0100

Due to climate change, more frequent and extreme weather events will lead to extreme heat, drought and"br" precipitation. This may affect the functionality of (federal) highways and therefore pose a risk for safety and"br" traffic flow. As the asset manager of the main road system in The Netherlands, Rijkswaterstaat has to ensure that"br" road networks continue their operational functions, both now and in the future. Therefore adaptation strategies"br" are needed to develop and maintain climate resilient infrastructure, integrated in the environment. To develop"br" such a strategy, the ROADAPT methodology - developed in response to the ‘CEDR call 2012: Road owners"br" adapting to climate change’ – and Dynamic Adaptation Policy Pathways were tested on a planned Dutch"br" highway project, InnovA58. This paper elaborates on this test and derives lessons for broader application. By"br" this paper the authors wish to contribute to the discussion about creating climate resilient road infrastructure as"br" integral part of their environment.

RAMSSES – Realisation and Demonstration of Advanced Material Solutions for Sustainable and Efficient Ships

Scipedia content — Thu, 28 Jan 2021 21:04:28 +0100

The RAMSSES project aims to show the benefits of advanced materials in maritime applications by implementing 13 market driven demo cases. The entire process chain and a wide range of applications (structural components, equipment, ship integration, repair) are covered. Installation and assessment of demonstrators on shore or on board will reveal the high technology readiness. The test program, based on risk assessment and supervised by rule making bodies, targets on ensuring relevance for commercial approval beyond the project. While demonstrators will support commercialisation of specific products, RAMSSES is also engaged strategically in enabling more rapid and agile material innovation in the European Maritime industry. The first key element is a knowledge repository for test data and best practice procedures, allowing reuse of such information for similar future cases. Secondly, standardised risk scenarios will help easing approval processes in the future, and finally a new materials innovation platform will enhance continuous technology transfer within the maritime sector and beyond.

Pulled Plug-flow Model for 4th Generation District Heating

Scipedia content — Thu, 28 Jan 2021 21:03:47 +0100

The controlling of modern district heating systems requires accurate models and simulation tools. The description and necessary verification of a model that sets these ambitions is a matter of this contribution. The model comes out of the known method-plug flow modelling. The implemented model works on the pulling principle when the amount of heat from the producer is "pulled" by the customer. The model was implemented and verified on the date of the local operator of the heating plant and distribution network. The model has been set to the parameters of the part of a real DH network, and its accuracy has been tested about traffic delays and heat loss in the pipelines. For the present experiment, the full knowledge of the heat demand was considered. These were optimal conditions and perhaps not just because of it the result that the pull plug flow model achieved was a quite good matching the measured and calculated values. (C) 2019, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

Technology Agency of the Czech Republic [TH02020979]

Monitoring work parameters for road transport means

Scipedia content — Thu, 28 Jan 2021 21:02:44 +0100

Method for Optimizing Supply Chain Flexibility in the Production of Electrified Powertrains

Scipedia content — Thu, 28 Jan 2021 20:59:15 +0100

Electromobility is one of the main solutions for tackling current challenges such as climate change or the scarcity of fossil resources [1]. Currently, there are large uncertainties regarding future production volumes of electric vehicles with forecast for 2025 varying between 4 % and 38% [2]–[4]. This demand volatility combined with rising importance of supply chain partners requires a fast adaptability of production volumes within the supply chain leading to a higher need of supply chain flexibility [1]. In this paper we present a method to optimize the contractual volumes between two supply chain partners coordinated by a quantity flexibility contract with fixed flexibility. Specifically, we examine whether a quantity flexibility contract fulfils its coordinating role in settings of changeable production systems. We validate our method with an example from the production of electrified automotive powertrains. The results show that we can further improve both costs and supply chain flexibility but that the coordinating role of the quantity flexibility contract is limited.

Mobility tools and use: Accessibility's role in Switzerland

Scipedia content — Thu, 28 Jan 2021 20:58:59 +0100

In much of Switzerland, public transport offers high levels of accessibility to workplaces and other places that make season tickets legitimate substitutes for a car. These similar patterns of accessibility provided by both modes result in high levels of correlation between the accessibility measures of both modes. This correlation almost always precludes a travel behavior analysis with several accessibility measures and cannot provide any insights into the effects of the differences in accessibility levels by both modes. We propose a principal component analysis of the accessibility measures to extract as much information as possible. We interpret the principal components obtained as: general accessibility, comparatively better accessibility by public transport and comparatively better job accessibility. The new accessibility variables are used in a model of car and season ticket ownership and the number of car, public transport and non-motorized trips using data from the 2010 Swiss transportation microcensus. These outcomes are jointly estimated with a probit-based model for mixed types of outcomes because we anticipated simultaneous choices and that choices are dependent on each other. We found that greater levels of general accessibility, comparatively better accessibility by public transport and comparatively better job accessibility increased the probability of season ticket ownership, while the probability of car ownership decreased. We realize that ownership and use must be jointly modeled to consistently estimate the structural effects of mobility tool ownership on use. ISSN:1938-7849

Characteristics of Single Vehicle Accidents in Europe

Scipedia content — Thu, 28 Jan 2021 20:58:19 +0100

out 102.000 people were killed in single vehicle accidents in the 28 European Union countries between 2006 and 2015, representing almost one third of all road accident fatalities in these countries. Single vehicle collision is a type of road accident in which only one vehicle and no other road user is involved. The objective of this research is the analysis of characteristics of single vehicle accidents in European countries through the use of the EU CARE database with disaggregate data on road accidents, as well as of other European data sources (e.g. Eurostat). Time-series data from the EU countries over a period of 10 years (2006-2015) were correlated with basic safety parameters, such as mode of transport, type of road, presence of junction, lighting and weather conditions, seasonality and person related characteristics like age and gender. The results of the analysis allow for an overall assessment of the safety level concerning single vehicle accidents in Europe in comparison to other types of accidents, thus providing useful support to decision makers working for the improvement of safety in the European road network.

Traffic analysis, fairway alignment and efficient investments in the waterway Danube

Scipedia content — Thu, 28 Jan 2021 20:57:39 +0100

Recent research on traffic development and transport economics in the Danube corridor revealed the importance"br" of improved navigation conditions on the waterway Danube. The Waterway Asset Management System (WAMS)"br" of viadonau allows a real-time calculation of fairway availability, planning of dredging measures, sediment"br" management and budget estimations for various target conditions. Aligning the fairway path and narrowing the"br" fairway width are very cost-efficient solutions especially in low water periods. However, actual vessel trajectories"br" and draughts loaded show deviations leading to questions regarding vessel course and loading capacity alignment."br" Based on anonymized traffic data and vessel trajectories a utilization analysis regarding available fairway depths"br" and distribution of traffic flows has been implemented in the WAMS. The paper provides an overview on the"br" results and direct consequences for the optimization of maintenance measures and fairway alignment. Future"br" developments may allow route planning and an optimization of vessel loading on the entire waterway.

The Competition and Cooperation between China's Civil Aviation Transport and High-Speed Railway

Scipedia content — Thu, 28 Jan 2021 20:52:49 +0100

Market-driven Derivation of Field Performance Requirements for Conceptual Aircraft Design

Scipedia content — Thu, 28 Jan 2021 20:47:55 +0100

n approach to derive a take-off field length for the initial specification of a new aircraft design is introduced in this paper. Based on a passenger demand forecast the runway lengths of the origin and destination airports are analyzed. The physical lengths of the runways are corrected by airports’ elevation and reference temperatures. The approach to derive airport reference temperatures on air transport system level is described in more detail. For an exemplary range of flight distances and the corresponding market, runway lengths are determined and corrected. Consequently the percentage of passenger demand can be described as a function of runway lengths. The example illustrates that airports’ elevation and reference temperature significantly affect the percentage of passenger demand that can be accommodated by an aircraft design for a given take-off field length.

Automated vehicles in a major European city – a technical perspective on urban transport policy options: the case of Vienna

Scipedia content — Thu, 28 Jan 2021 20:47:38 +0100

Introducing automated vehicles to the urban mobility system will certainly bring changes for mobility behavior and will thus impact the effects of traffic in the city. The development path is very uncertain from a current perspective but several opportunities and risks can be envisioned. Several experts in the Vienna City Administration have seized the opportunity to reflect on the City’s objectives for urban and transport development matching them with expected risks and opportunities in this formative phase. In addition, instruments at the disposal of an urban municipal administration were collected in the areas of “public spaces and street infrastructure”, “land use and settlement patterns” and “traffic system management”, which could help gearing developments towards the transport policy goals. It is expected that the findings are valid and applicable to a large extent to other large European Cities.

Co-simulation framework for control, communication and traffic for vehicle platoons

Scipedia content — Thu, 28 Jan 2021 20:42:20 +0100

Vehicle platooning has gained attention for its potential to achieve an increased road capacity and safety, and a higher fuel efficiency. Member vehicles of a platoon wirelessly communicate complying with industrial standards such as IEEE 802.11p. By exchanging information with other members via wireless communication, a platoon member computes its desired acceleration which is then passed on to the engine control system via in-vehicle network to physically realize the acceleration. This leads to a multi-layer control scheme. The upper-layer is influenced by the behavior of 802.11p communication and network congestion due to transmissions by other vehicles in the traffic. The lower-layer engine control loop communicates over the fast and reliable in-vehicle networks (e.g., FlexRay, Ethernet). Design of the overall system therefore depends on (i) the characteristics of 802.11p-based communication (ii) the nature of the traffic (iii) the control algorithms running at the two layers. We present a cosimulation framework consisting of Matlab (for the multi-layer control algorithms), ns-3 (for the 802.11p network) and SUMO (for the traffic behavior). The framework can be used to validate different platooning setups. As an illustrative case study, we consider a multi-layer control strategy where the upper-layer uses Model Predictive Control (MPC) at a rate in compliance with 802.11p and the lower-layer uses statefeedback control at a higher sampling rate in line with in-vehicle networking capabilities. The control strategy is evaluated considering various realistic traffic and network congestion scenarios. © 2018 IEEE.

A comprehensive approach to increase energy efficiency of bus systems: methodology and directions from the EBSF_2 project

Scipedia content — Thu, 28 Jan 2021 20:42:03 +0100

EBSF_2 is a research project led by the International Association of Public Transport and funded by the"br" European Union with the aim of increasing attractiveness and efficiency of urban bus systems. EBSF_2"br" combines experiments with research as it relies on demonstrators, i.e. innovative technologies are tested on"br" vehicles operating in 12 European bus networks and evaluated through a methodology to assess the soundness of"br" the innovations and their affordability. The innovations under test are different, but increased energy efficiency"br" is the goal for several test sites which are working to: a) advance energy management of buses, b) lower the"br" energy needed for on-board heating, ventilating and cooling; c) develop energy-efficient driver support systems."br" The paper describes how the topic energy efficiency is addressed within the EBSF_2 demonstrators. The"br" assessment methodology designed to measure the performance variations in each demonstrator and cross-case is"br" presented, together with the testing scenarios for three demonstrators and the preliminary results achieved.

On-the-fly mobility event detection over aircraft trajectories

Scipedia content — Thu, 28 Jan 2021 20:41:02 +0100

We present an application framework that consumes streaming positions from a large fleet of flying aircrafts monitored in real time over a wide geographical area. Tailored for aviation surveillance, this online processing scheme only retains locations conveying salient mobility events along each flight, and annotates them as stop, change of speed, heading or altitude, etc. Such evolving trajectory synopses must keep in pace with the incoming raw streams so as to get incrementally annotated with minimal loss in accuracy. We also develop one-pass heuristics to eliminate inherent noise and provide reliable trajectory representations. Our prototype implementation on top of Apache Flink and Kafka has been tested against various real and synthetic datasets offering concrete evidence of its timeliness, scalability, and compression efficiency, with tolerable concessions to the quality of resulting trajectory approximations. K. Patroumpas, N. Pelekis, and Y. Theodoridis: "On-the-fly Mobility Event Detection over Aircraft Trajectories". In proceeding of the 26th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (ACM SIGSPATIAL 2018), November 6 - 9, 2018 Seattle, Washington, USA

Document type: Conference object

Energy efficient control of a heat pump in fully electric vehicle

Scipedia content — Thu, 28 Jan 2021 20:38:29 +0100

Since fully electric vehicles (FEV) do not have enough waste heat for cabin heating as internal combustion engine"br" (ICE) vehicles and hybrid vehicles do, it is beneficial to employ a reversible heat pump in FEVs. The reversible"br" heat pump can be used for both the cabin cooling and heating and especially under winter conditions it is able to"br" substantially improve the FEV driving range compared to heating with PTC heater."br" This paper is focused on energy efficient control for the reversible heat pumps using either R1234yf or R744"br" refrigerant. The main goal of these control algorithms is to achieve a satisfactory passenger thermal comfort with"br" as low as possible energy consumption.

Interoperability of IoT Platforms applied to the transport and logistics domain

Scipedia content — Thu, 28 Jan 2021 20:32:44 +0100

Transport and logistics is a very complex sector that has a significant impact in the environment and energy consumption as well as in the economic activities of a city. On a strategic sector such as the port, many of the issues regarding the current shipment management process are primarily due to the lack of interoperability among systems involved in this process which generally belong to Internet of Things platforms. Typically there is a lack of coordination of the stakeholders involved on the delivery and pick up of cargo in the port. When a truck accesses the port and arrives at the port gate, no notification is given to the container terminal’s IoT platform. Moreover, trucks entering the terminal area do not have access to the terminal IoT platform, which provides the information where the container should be picked from or delivered to. As a result, truck drivers have to seek further assistance to locate the specific place within the terminal area. Whereas the truck company is aware of the truck’s location, this information is not delivered to the terminal’s IoT platform. Consequently, inefficiencies are present in the process and the time of arrival of a specific truck to the target destination remains “unpredictable”. Therefore, it is vital to address interoperability in this heterogeneous and non-optimally coordinated environment. The present study proposes an approach to address seamless interoperability of existing systems and IoT platforms (e.g. road haulier ITS, port gate systems, port authority, container terminal and container terminal gate), which are heterogeneous and currently non-interoperable between each other. The solution offers significant advantages to stakeholders (i.e. port authority, terminal owners, truck drivers, cargo owners). Major advantages are the creation of smart new services such as an appointment service, driving guidance to containers, and a low-consumption dynamic lighting. The solution is based on a framework for platform interoperability provided by the Horizon 2020 European research project INTER-IoT, and it is applied to the terrestrial delivery and collection of cargo in a pilot scenario in the port of Valencia.

Comprehensive framework on asset management of transportation networks and resilience planning

Scipedia content — Thu, 28 Jan 2021 20:31:05 +0100

This paper aims to provide proper guidelines for supporting decision-making and prioritization of infrastructure investments and actions. It is based on a framework for asset management of transportation networks. The paper emphasizes the enhancement of resilience of the transport systems, covering multimodal network aspects. The proposed framework promotes a fully functional transport network, optimizing processes at a cross modal and cross border level. Guidance is provided on how to enrich and support the individual, institutional and political action arenas. The main effort is to develop synergies at a cross border and cross modal level and for this reason cooperative solutions offering mutual gain are promoted. Overall, the guidelines ensure the effective use of the generic framework, which could constitute the basis for asset management of National Infrastructure Agencies considering also resilience, as well as regional planning objectives, social factors and criteria.

Electronic decisions for public transport lines

Scipedia content — Thu, 28 Jan 2021 20:30:18 +0100

Public transport services in Austria require a license of the provincial administration for the lines and stops. The administration checks whether the public transport service is compatible with the road infrastructure and the traffic conditions. The stops must conform to common standards and to the safety requirements according to estimated use."br" The Graph Integration Platform (GIP) is a common geographic reference system for traffic and transport infrastructure in Austria. It is now fully functional, constantly up-to-date and available in very good accuracy all over the country. Several administrative procedures have been converted to computer assisted processes and based on the common reference graph. The licenses for public transport are relevant for the administration of the province and for the public transport associations that procure public transport operation from private operators, promote the services and sell the tickets. The effort to match the schedules for public transport with the legal licenses issued by the administration was prohibitive in the past."br" The licenses in all nine Austrian provinces are based on the same federal law. Nevertheless, there are substantial differences between procedures applied in the provinces. The progress of digitalization also differs: some provinces use text processor (mostly MS Word) others use administrative document management systems as a standard. Different approaches were discussed with the people in charge of the federally funded project GIP E-II. Finally, a prototype that would fit the requirements and procedures of the administration in Lower Austria and Burgenland was developed. Care had been taken, that the additional requirements of other provinces can easily be incorporated into a future version. The public transport schedule maintained by the public transport association was compared with the digitally available data in the provinces and became the basis for a basic data set to start with. As the bus lines are tendered by the traffic association in regular intervals, a fully up-to-date version of the licenses will be part of the system by 2020.

Lane splitting experiment: comparative analysis of how this is accepted by motorcyclists and car drivers

Scipedia content — Thu, 28 Jan 2021 20:29:09 +0100

TRA 2018 - 7th Transport Research Arena : A digital era for transport, Vienne, AUTRICHE, 16-/04/2018 - 19/04/2018; Lane splitting is a common riding practice although forbidden by the traffic rules in France. Since February 1st, 2016, a secure shape of traffic, respectful of certain rules is allowed on motorways and urban expressways in several French departments. The objective here is to present the results concerning the acceptability of this secure form of lane splitting for motorcyclists and car drivers. 908 car drivers and motorcyclists, representative samples of the French population (in terms of sex, age and socio-professional category) were interviewed. 751 lived in the experimental area and 157, in the control area where lane splitting is not allowed. The results show that the car drivers and the motorcyclists evaluate positively the experiment, the attitude of the experiment is even more positive for the motorcyclists. But, the car drivers have some reservations about the difficulty to understand where lane splitting is allowed. The results are discussed. As we will be replicating this research in 2017 and 2018, in order to study changes in how the experiment is accepted in the long term, at the end we will have some helpful elements, to decide if LS could be allowed in France.; La circulation inter-files est une pratique courante bien qu'interdite par les règles de circulation en France. Depuis le 1er février, 2016, un trafic sécurisé, respectueux de certaines règles est autorisé expérimentalement sur les autoroutes et autoroutes urbaines dans plusieurs départements français. L'objectif ici est de présenter les résultats concernant l'acceptabilité de cette forme sécurisée de la circulation inter-files chez les motocyclistes et les automobilistes. 908 automobilistes et motocyclistes, constituant un échantillon représentatif de la population française (en termes de sexe, d'âge et catégorie socioprofessionnelle), ont été interviewés. 751 résidaient dans la zone expérimentale et 157 dans la zone de contrôle où la circulation inter-files n'est pas autorisée. Les résultats montrent que les automobilistes et les motocyclistes évaluent positivement l'expérimentation, avec une attitude encore plus positive chez les motocyclistes. Les automobilistes expriment des réserves liées la difficulté à identifier les zones où la circulation inter-files est autorisée. Cette étude sera répliquée en 2017 et 2018 afin d'étudier les changements dans la façon dont l'expérimentation est acceptée à long terme.

Document type: Conference object

Smartness of urban mobility and "quality of life" in Vienna

Scipedia content — Thu, 28 Jan 2021 20:28:23 +0100

The concept of “smartness” is based on expectation. “Quality of Life” is based on experience. The “learning process” between expectation and experience in Vienna was accompanied by scientific analyses over many decades. They show the chances and the risks – and also the luck – that the city had in the past. In a dynamic city there are always intentions for decisions and projects from the inside and the outside which have to be analysed, whether the outcome will have positive or negative effects on the future development of the city. The future will need more cooperation than competition between cities to keep transport and quality of life in balance not only in the city but also with the surrounding region."br" This paper will give a comprehensive insight into the content of the studies of the processes based on the experience and data from the past, the stability of the existing situation of the urban structure of Vienna city and its internal dynamics, and the outlook into the opportunities and risks of the future of the city, as far as scientific methods allow.

Multidimensional comparative analysis of transport behaviour of urban residents: the case of Polish cities

Scipedia content — Thu, 28 Jan 2021 20:28:07 +0100

The aim of the work is to conduct a multidimensional modelling of transport behaviour of residents of cities in Poland. The research was carried out on the basis of the pilot sample survey results conducted by Polish Central Statistical Office in 2014-2015. In the work a correspondence analysis was used to study the transport behaviour of urban residents. In the study the relationship between the frequency of journeys within the city and factors describing them were investigated. The research analysed primarily the interdependence between the intensity of travels made by residents within the city and factors describing these travels, such as structure of travel, destination, time interval of journeys or methods of travel. On this basis, a profound analysis of the transport behaviour of urban residents was carried out. The study results presented in this work can be a useful tool for local authorities in order to forecast the travel behaviour of urban residents.

Modeling and calculation of the stress-strain state of buried pipelines taking into consideration the soil ice

Scipedia content — Thu, 28 Jan 2021 20:24:37 +0100

Design, Development and Implementation of a Network Intrusion Detection Tool for Air Traffic Management Systems

Scipedia content — Thu, 28 Jan 2021 20:23:25 +0100

n Air Traffic Management (ATM) relies on a set of critical systems composed of control centers, sensors, communication means and radio navigation systems. These critical systems may be subject to different attacks and thus compromise their security. Indeed as there is a desire to open this system more and more outward and there is a gap between this world and the interconnected world, threats are increasing. The ATM system have particular characteristics as the fact that it is a very distributed system with a lot of real-time applications using proprietary and/or legacy protocols. Thus, the need to have an efficient Intrusion Detection System (IDS) is primordial in terms of reliability (a false negative rate as low as possible) and relevance (a lowest possible false-positive rate). The development of an IDS combining misuse detection (i.e., defining attack scenarios and finding traces of these scenarios in the traffic.) and anomaly detection (i.e., the construction of a reference model of the behavior of the supervised entity to which we will be able to compare the observed behavior) based on wavelet theory is a promising approach as they are already shown for this type of systems. The detection capability for such complex system could be enhanced using the specific characteristics of its exchanges, use them to enrich its normal signature and reduce the probability of false positive and false negatives. This paper describes the context and the state of the art of the current research direction of the authors with the aim to present the challenges and the future works that the student aims to perform in the next years.

Detector technology for demand responsive traffic signal control under mixed traffic conditions

Scipedia content — Thu, 28 Jan 2021 20:22:52 +0100

In general, traffic signal control used at signalised intersections in Indonesia is Fixed Time Control (FTC). It shows good results in conditions where there is a little fluctuation in traffic demand. However, in time-varying traffic, FTC becomes inflexible and inefficient. This situation may trigger traffic congestion and lead to increased delays and air pollution. Demand Responsive Traffic Signal Control (DRTSC), such as Vehicle Actuated Control (VAC) and Adaptive Traffic Signal Control (ATSC), have been introduced to overcome these problems. However, all the available demand responsive traffic signal control methods have been developed for non-mixed traffic conditions. The objectives of this literature review was to investigate the traffic parameter for input data of DRTSC under mixed traffic conditions and to identify the most suitable detector technology for providing traffic information to DRTSC under mixed traffic conditions. Based on the extensive literature review on the traffic signal control strategies and the detector technologies, queue length (meter) and occupancy rate (%) provided by VIP system are the most suitable input data for a DRTSC under mixed traffic conditions.

Adaptable Emergency Braking Based on a Fuzzy Controller and a Predictive Model

Scipedia content — Thu, 28 Jan 2021 20:19:24 +0100

This work presents the implementation of an adaptable emergency braking system for low speed collision avoidance, based on a frontal laser scanner for static obstacle detection, using a D-GPS system for positioning. A fuzzy logic decision process performs a criticality assessment that triggers the emergency braking system and modulates its behavior. This criticality is evaluated through the use of a predictive model based on a kinematic estimation, which modulates the decision to brake. Additionally a critical study is conducted in order to provide a benchmark for comparison, and evaluate the limits of the predictive model. The braking decision is based on a parameterizable braking model tuned for the target vehicle, that takes into account factors such as reaction time, distance to obstacles, vehicle velocity and maximum deceleration. Once activated, braking force is adapted to reduce vehicle occupants discomfort while ensuring safety throughout the process. The system was implemented on a real vehicle and proper operation is validated through extensive testing carried out at Tecnalia facilities. This project has received funding from the Electronic Component Systems for European Leadership Joint Undertaking under grant agreement No 692480. This Joint Undertaking receives support from the European Unions Horizon 2020 research and innovation programme and Germany, Netherlands, Spain, Austria, Belgium, Slovakia.

On the correlation between volume change of anode materials in Li-ion cells and their degradation and failure

Scipedia content — Thu, 28 Jan 2021 20:18:25 +0100

ming at increasing the energy density of lithium ion batteries, a Si alloy/graphite blend was used as anode material, replacing traditional pure graphite anodes. For the first time an in-situ in-operando electrochemical dilatometry was used to evaluate the expansion and contraction of this novel Si-alloy anode materials during electrochemical cycling under constant temperature. The results show an increase in volume for the first cycle (80 %) with around 12 % irreversible expansion, while for graphite based anode these values are 10% and 3%, respectively. These volume variations require particular attention when producing commercial cells. As a complementary study, commercial 18650 cells with graphite anode were investigated and the mechanical effects – jelly roll deformation – after cycling were studied by X-ray computed tomography. The deformation found for graphite electrode elucidates the importance of understanding and quantifying swelling of Si electrodes for commercial cells.