Evaluation of an Autonomous Vehicle User Interface for Sensory Impaired Users

Autonomous vehicles (AVs) hold immense promises in revolutionizing transportation, and their potential benefits extend to individuals with impairments, particularly those with vision and hearing impairments. However, the accommodation of these individuals in AVs requires developing advanced user interfaces. This paper describes an explorative study of a multimodal user interface for autonomous vehicles, specifically developed for passengers with sensory (vision and/or hearing) impairments. In a driving simulator, 32 volunteers with simulated sensory impairments, were exposed to multiple drives in an autonomous vehicle while freely interacting with standard and inclusive variants of the infotainment and navigation system interface. The two user interfaces differed in graphical layout and voice messages, which adopted inclusive design principles for the inclusive variant. Questionnaires and structured interviews were conducted to collect participants’ impressions. The data analysis reports positive user experiences, but also identifies technical challenges. Verified guidelines are provided for further development of inclusive user interface solutions.

Rail RCF damage quantification and comparison for different damage models

There are several fatigue-based approaches that estimate the evolution of rolling contact fatigue(RCF) on rails over time and built to be used in tandem with multibody simulations of vehicle dynamics. However, most of the models are not directly comparable with each other since they are based on different physical models even though they shall predict the same RCF damage at the end.This article studies different approaches to quantifying RCF and puts forward a measure for the degree of agreement between them. The methodological framework studies various steps in the RCF quantification procedure within the context of one another, identifies the ‘primary quantification step’ in each approach and compares results of the fatigue analyses. In addition to this, two quantities—‘similarity’ and ‘correlation’—have been put forward to give an indication of mutual agreement between models.Four widely used surface-based and sub-surface-based fatigue quantification approaches with varying complexities have been studied. Different operational cases corresponding to a metro vehicle operation in Austria have been considered for this study. Results showed that the best possible quantity to compare is the normalized damage increment per loading cycle coming from different approaches. Amongst the methods studied, approaches that included the load distribution step on the contact patch showed higher similarity and correlation in their results.While the different approaches might qualitatively agree on whether contact cases are ‘damaging’ due to RCF, they might not quantitatively correlate with the trends observed for damage increment values.

Cyclist Warning Systems: Design and Evaluation

Cyclists belong to the group of vulnerable road users and, thus, need particular protection in road traffic. One way to enhance cyclists’ safety is to use urban data (e.g., infrastructure data, accident statistics) to inform cyclists about potentially dangerous areas, allowing them to better adjust to the situation and elevate their self-protection. However, the question is how to inform cyclists about such dangerous areas. In this paper, we present the results of two field studies, investigating two wearables (headphones vs. smart glasses) and different signal options to inform cyclists about dangerous areas. Study participants were cycling along a predefined track and could experience the different wearables and signals. The main aim of the studies was to find out how cyclists perceive and experience the different approaches. Participants’ impressions were captured with questionnaires and interviews. Our results show a clear preference of the headphones over the smart glasses and signaling with intermittent audio while being in the dangerous area. However, we also found that participants’ acceptance of the approach was influenced by the additional perceived benefit the respective wearable would have in daily life. Using a wearable solely to be warned, although this would increase safety, was less acceptable. We discuss the implications of these findings for the design of cyclist warning systems.

Testing and modelling of transient adhesion phenomena in rolling-sliding contacts

Transient adhesion effects in rolling–sliding contacts influence all aspects of train–track interaction.This is of high importance specifically when these effects result in critically low adhesion,which poses a risk to traction and braking of railway vehicles.This study presents a model that can replicate the transient changes of the coefficient of adhesion with tested water and solid particle mix.The experimental data for the model are measured using a commercial ball-on-disc tribometer.The experimental results showed a liquid reservoir in front of the contact area that slowly reduces in size.This observation was used in the modelling approach to divide the calculation into two stages where the reservoir is present and when it disappears.The model was able to reproduce the occurrence of low adhesion region seen in experimental results with different particle concentrations.

Erratum to:Testing and modelling of transient adhesion phenomena in rolling-sliding contacts

Erratum to Daniel Kvarda,Alexander Meierhofer,Klaus Six.Testing and modelling of transient adhesion phenomena in rolling–sliding contacts.Friction 12(5):1016–1027(2024).https://doi.org/10.1007/s40544-023-0825-8 The authors regret that there was an inadvertent error in author biographies after checking the paper.It is important to note that the change does not impact the main conclusion of the article.The accurate version of biographies of Alexander MEIERHOFER and Klaus SIX on pages 1026 and 1027 are provided as below.