9 research outputs found

    Evaluation of Haptic Patterns on a Steering Wheel

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    Infotainment Systems can increase mental workload and divert visual attention away from looking ahead on the roads. When these systems give information to the driver, provide it through the tactile channel on the steering, it wheel might improve driving behaviour and safety. This paper describes an investigation into the perceivability of haptic feedback patterns using an actuated surface on a steering wheel. Six solenoids were embedded along the rim of the steering wheel creating three bumps under each palm. Maximally, four of the six solenoids were actuated simultaneously, resulting in 56 patterns to test. Participants were asked to keep in the middle road of the driving simulator as good as possible. Overall recognition accuracy of the haptic patterns was 81.3%, where identification rate increased with decreasing number of active solenoids (up to 92.2% for a single solenoid). There was no significant increase in lane deviation or steering angle during haptic pattern presentation. These results suggest that drivers can reliably distinguish between cutaneous patterns presented on the steering wheel. Our findings can assist in delivering non-critical messages to the driver (e.g. driving performance, incoming text messages, etc.) without decreasing driving performance or increasing perceived mental workload

    Optimising landmark-based route guidance for older drivers

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    In-vehicle navigation systems (IVNS) have the potential to benefit older drivers, reducing stress associated with way-finding and providing on-trip support, especially in unfamiliar locations. However, existing IVNS present challenges to usability, resulting in lack of uptake and over-reliance on pre-trip planning. This paper presents research aimed at identifying features that make IVNS user-friendly and appropriate for older drivers. Studying navigational performance within a simulated driving environment, it focuses on the use of landmarks with route guidance information, and the most appropriate method of information provision (audio only, visual only or a combination of audio and visual). It also assesses potential gender differences that might arise with landmark-based navigational information. Solutions include use of appropriate roadside landmarks, and information delivered through a combination of audio and icon-based visual format. These features result in lower workload and fewer navigational errors. The audio/visual modality reduces the hazard of distraction by landmarks resulting in fewer visual glances and lower glance duration to the roadside compared to other modalities. Design and provision of IVNS tailored to older drivers’ needs can make a considerable contribution to maintaining individual mobility for longer

    Kinesthesia in a sustained-attention driving task

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    This study investigated the effects of kinesthetic stimuli on brain activities during a sustained-attention task in an immersive driving simulator. Tonic and phasic brain responses on multiple timescales were analyzed using time-frequency analysis of electroencephalographic (EEG) sources identified by independent component analysis (ICA). Sorting EEG spectra with respect to reaction times (RT) to randomly introduced lane-departure events revealed distinct effects of kinesthetic stimuli on the brain under different performance levels. Experimental results indicated that EEG spectral dynamics highly correlated with performance lapses when driving involved kinesthetic feedback. Furthermore, in the realistic environment involving both visual and kinesthetic feedback, a transitive relationship of power spectra between optimal-, suboptimal-, and poor-performance groups was found predominately across most of the independent components. In contrast to the static environment with visual input only, kinesthetic feedback reduced theta-power augmentation in the central and frontal components when preparing for action and error monitoring, while strengthening alpha suppression in the central component while steering the wheel. In terms of behavior, subjects tended to have a short response time to process unexpected events with the assistance of kinesthesia, yet only when their performance was optimal. Decrease in attentional demand, facilitated by kinesthetic feedback, eventually significantly increased the reaction time in the suboptimal-performance state. Neurophysiological evidence of mutual relationships between behavioral performance and neurocognition in complex task paradigms and experimental environments, presented in this study, might elucidate our understanding of distributed brain dynamics, supporting natural human cognition and complex coordinated, multi-joint naturalistic behavior, and lead to improved understanding of brain-behavior relations in operating environments. © 2014 Elsevier Inc

    Electroencephalographic Responses to Frictional Stimuli: Measurement Setup and Processing Pipeline

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    Tactility is a key sense in the human interaction with the environment. The understanding of tactile perception has become an exciting area in industrial, medical and scienti c research with an emphasis on the development of new haptic technologies. Surprisingly, the quanti cation of tactile perception has, compared to other senses, only recently become a eld of scienti c investigation. The overall goal of this emerging scienti c discipline is an understanding of the causal chain from the contact of the skin with materials to the brain dynamics representing recognition of and emotional reaction to the materials. Each link in this chain depends on individual and environmental factors ranging from the in uence of humidity on contact formation to the role of attention for the perception of touch. This thesis reports on the research of neural correlates to the frictional stimulation of the human ngertip. Event-related electroencephalographic potentials (ERPs) upon the change in ngertip friction are measured and studied, when pins of a programmable Braille-display were brought into skin contact. In order to contribute to the understanding of the causal chain mentioned above, this work combines two research areas which are usually not connected to each other, namely tribology and neuroscience. The goal of the study is to evaluate contributions of friction to the process of haptic perception. Key contributions of this thesis are: 1) Development of a setup to simultaneously record physical forces and ERPs upon tactile stimulation. 2) Implementation of a dedicated signal processing pipeline for the statistical analysis of ERP -amplitudes, -latencies and -instantaneous phases. 3) Interpretation of skin friction data and extraction of neural correlates with respect to varying friction intensities. The tactile stimulation of the ngertip upon raising and lowering of di erent lines of Braille-pins (one, three and ve) caused pronounced N50 and P100 components in the event-related ERPsequences, which is in line with the current literature. Friction between the ngertip and the Braille-system exhibited a characteristic temporal development which is attributed to viscoelastic skin relaxation. Although the force stimuli varied by a factor of two between the di erent Braillepatterns, no signi cant di erences were observed between the amplitudes and latencies of ERPs after standard across-trial averaging. Thus, for the rst time a phase measure for estimating singletrial interactions of somatosensory potentials is proposed. Results show that instantaneous phase coherency is evoked by friction, and that higher friction induces stronger and more time-localized phase coherencyDie Taktilität ist ein zentraler Sinn in der Interaktion mit unserer Umwelt. Das Bestreben, fundierte Erkenntnisse hinsichtlich der taktilenWahrnehmung zu gewinnen erhält groÿen Zuspruch in der industriellen, medizinischen und wissenschaftlichen Forschung, meist mit einem Fokus auf der Entwicklung von haptischen Technologien. Erstaunlicherweise ist jedoch die wissenschaftliche Quanti zierung der taktilen Wahrnehmung, verglichen mit anderen Sinnesmodalitäten, erst seit kurzem ein sich entwickelnder Forschungsbereich. Fokus dieser Disziplin ist es, die kognitive und emotionale Reaktion nach physischem Kontakt mit Materialien zu beschreiben, und die kausale Wirkungskette von der Berührung bis zur Reaktion zu verstehen. Dabei unterliegen die einzelnen Faktoren dieser Kette sowohl individuellen als auch externen Ein üssen, welche von der Luftfeuchtigkeit während des Kontaktes bis hin zur Rolle der Aufmerksamkeit für die Wahrnehmung reichen. Die vorliegende Arbeit beschäftigt sich mit der Untersuchung von neuronalen Korrelaten nach Reibungsstimulation des menschlichen Fingers. Dazu wurden Reibungsänderungen, welche durch den Kontakt der menschlichen Fingerspitze mit schaltbaren Stiften eines Braille-Display erzeugt wurden, untersucht und die entsprechenden neuronalen Korrelate aufgezeichnet. Um zu dem Verst ändnis der oben erwähnten Wirkungskette beizutragen, werden Ansätze aus zwei für gewöhnlich nicht zusammenhängenden Forschungsbereichen, nämlich der Tribologie und der Neurowissenschaft, kombiniert. Folgende Beiträge sind Hauptbestandteile dieser Arbeit: 1) Realisierung einer Messumgebung zur simultanen Ableitung von Kräften und ereigniskorrelierten Potentialen nach taktiler Stimulation der Fingerspitze. 2) Aufbau einer speziellen Signalverarbeitungskette zur statistischen Analyse von stimulationsabh ängigen EEG -Amplituden, -Latenzen und -instantanen Phasen. 3) Interpretation der erhobenen Reibungsdaten und Extraktion neuronaler Korrelate hinsichtlich variierender Stimulationsintensitäten. Unsere Resultate zeigen, dass die taktile Stimulation der Fingerspitze nach Anheben und Senken von Braille-Stiften zu signi kanten N50 und P100 Komponenten in den ereigniskorrelierten Potentialen führt, im Einklang mit der aktuellen Literatur. Die Reibung zwischen der Fingerspitze und dem Braille-System zeigte einen charakteristischen Signalverlauf, welcher auf viskoelastische Hautrelaxation zurückzuführen ist. Trotz der um einen Faktor zwei verschiedenen Intensit ätsunterschiede zwischen den Stimulationsmustern zeigten sich keine signi kanten Unterschiede zwischen den einfach gemittelten Amplituden der evozierten Potentialen. Erstmalig wurde ein Phasen-Maÿ zur Identi zierung von Unterschieden zwischen somatosensorischen "single-trial" Interaktionen angewandt. Diese Phasenanalyse zeigte, im Gegensatz zur Amplituden- und Latenzanalyse, deutlichere und signi kantere Unterschiede zwischen den Stimulationsparadigmen. Es wird gefolgert, dass Kohärenz zwischen den Momentanphasen durch Reibungsereignisse herbeigef ührt wird und dass durch stärkere Reibung diese Kohärenz, im zeitlichen Verlauf, stärker und lokalisierter wird

    Supporting Eyes-Free Human–Computer Interaction with Vibrotactile Haptification

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    The sense of touch is a crucial sense when using our hands in complex tasks. Some tasks we learn to do even without sight by just using the sense of touch in our fingers and hands. Modern touchscreen devices, however, have lost some of that tactile feeling while removing physical controls from the interaction. Touch is also a sense that is underutilized in interactions with technology and could provide new ways of interaction to support users. While users are using information technology in certain situations, they cannot visually and mentally focus completely during the interaction. Humans can utilize their sense of touch more comprehensively in interactions and learn to understand tactile information while interacting with information technology. This thesis introduces a set of experiments that evaluate human capabilities to understand and notice tactile information provided by current actuator technology and further introduces a couple of examples of haptic user interfaces (HUIs) to use under eyes-free use scenarios. These experiments evaluate the benefits of such interfaces for users and concludes with some guidelines and methods for how to create this kind of user interfaces. The experiments in this thesis can be divided into three groups. In the first group, with the first two experiments, the detection of vibrotactile stimuli and interpretation of the abstract meaning of vibrotactile feedback was evaluated. Experiments in the second group evaluated how to design rhythmic vibrotactile tactons to be basic vibrotactile primitives for HUIs. The last group of two experiments evaluated how these HUIs benefit the users in the distracted and eyes-free interaction scenarios. The primary aim for this series of experiments was to evaluate if utilizing the current level of actuation technology could be used more comprehensively than in current-day solutions with simple haptic alerts and notifications. Thus, to find out if the comprehensive use of vibrotactile feedback in interactions would provide additional benefits for the users, compared to the current level of haptic interaction methods and nonhaptic interaction methods. The main finding of this research is that while using more comprehensive HUIs in eyes-free distracted-use scenarios, such as while driving a car, the user’s main task, driving, is performed better. Furthermore, users liked the comprehensively haptified user interfaces

    INTERACTION BETWEEN SIGNAL COMPLEXITY AND PHYSICAL ACTIVITY IN VIBRO-TACTILE COMMUNICATION

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    Master'sMASTER OF ART

    Investigating older drivers' route guidance requirements to inform the design of future in-vehicle navigation systems

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    Phd ThesisIn-vehicle navigation has been identified as a key activity for maintaining the mobility and hence the independence and quality of life of older adults. However, few studies have directly investigated and tested route guidance requirements specifically for older drivers. This thesis addresses the knowledge gap using a range of quantitative and qualitative methodologies across three investigations. A focus group investigation was undertaken first. Thirty older adults were recruited and themes of driving and navigation behaviour discussed. This research stage found older adults have difficulty planning and then navigating journeys, landmarks are used to navigate the road network and in-vehicle navigation systems (IVNS) are not deemed to be useable. In the second investigation, current design IVNS were loaned to 22 older adults for a two-week period. During this period the participants detailed their experiences and attitudes of the loaned IVNS. In addition, in-depth interviews were undertaken. This investigation found that IVNS have usability issues for older drivers that need to be considered for the next generation of IVNS. In the next stage, a driving simulator investigation with 30 older drivers was carried out. This phase of the research examined the navigational benefits of providing landmark-based route guidance information as compared to the traditional method of paper maps. The study concluded that older drivers have difficulties with navigation through decline in memory and vision. The driving simulator investigation suggests that landmarks are effective at supporting older drivers with the navigation task; in particular, older female drivers. In addition, landmark-based route guidance information should be delivered through a combination of audio instructions and an icon-based visual display. Finally, the thesis outlines recommendations for the next generation IVNS for older drivers

    L’approche par les capabilités un nouveau cadre pour l’analyse de l’accessibilité universelle : application à la mobilité des personnes vieillissantes.

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    Objective: The objective of this work was to propose a new approach for the understanding of accessibility. Through this approach, accessibility is considered as a number of qualities of environments or activities providing real opportunities for development to people. This line of research was based on the capability approach which provides a unique and relevant theoretical framework to achieve enabling accessibility (i.e. accessibility which offers real development opportunities to people). In this thesis, the application context of enabling accessibility is older adults’ mobility. Methods: After a presentation of the capability approach, a state of the art on accessibility and presentation of the application context of this research, we present three studies, which use a combination of methods (i.e. workshop, observations, survey, situational projection, critical incident technique). Results: The results of this research are used to define a model of enabling accessibility and to clarify its position in ergonomics. This model highlights a number of determinants of enabling accessibility (e.g. resources conversion factors, factors of choice). This model also describes a number of process which can constraint or hamper activity. Conclusion: In conclusion, a presentation of the model develops in this work is proposed as well as a definition of enabling accessibility. The prospects for research focuses firstly on the research design for enabling accessibility, and secondly, on the long-term effects of enabling accessibility on meta-functional activities.Keywords: enabling accessibility, capability approach, freedom of choice, older people, mobilityObjectif : L’objectif de ce travail de thèse était de proposer une nouvelle approche pour appréhender l’accessibilité afin qu’elle offre des opportunités réelles aux personnes de se déplacer et de se développer. Cette orientation de recherche s’est appuyée sur l’approche par les capabilités qui fournit un cadre théorique pertinent et original pour atteindre une accessibilité capacitante, c'est-à-dire qui permette le développement des personnes. Dans cette thèse, le cadre applicatif de l’approche théorique est la mobilité des personnes vieillissantes.Méthodes : Après une présentation de l’approche par les capabilités, un état de l’art sur l’accessibilité et la présentation du contexte applicatif de cette thèse, nous présentons trois recherches, qui utilisent une combinaison de méthodes (i.e. atelier, observations, questionnaires, projection situationnelle, technique des incidents critiques).Résultats : Les résultats de ces recherches permettent de définir l’accessibilité capacitante et de concevoir un modèle pour l’appréhender en ergonomie. Ce modèle met en évidence des déterminants de l’accessibilité capacitante tels que les ressources et les facteurs d’usage (i.e. les facteurs de conversion et les facteurs de choix). De plus, il décrit le processus qui peut amener à des activités contraintes et/ou empêchées.Conclusion : En conclusion, une présentation du modèle développé dans ce travail est proposée ainsi qu’une définition de l’accessibilité capacitante. Ensuite, les perspectives de recherches portent d’une part sur les recherches en conception visant l’accessibilité capacitante, et d’autre part, sur les effets à long terme de l’accessibilité capacitante sur les activités méta-fonctionnelles
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