Sensory feedback for supernumerary limbs

Supernumerary robotic limbs (SL) are devices developed to increase human capability. For this to happen, SLs should assist users with minimal cognitive effort and be controlled both independently and in combination with the user’s natural limbs. Despite the development of many SL, their application is limited by a lack of easy-to-use and intuitive controllers. Integrating somatosensory feedback in the control loop could improve this issue. In particular, providing artificial proprioception, a somatosensory modality important for motor control, could help SL users to integrate the SL into their planning and body schema. My objective is to find strategies to deliver intuitive and understandable proprioceptive feedback from a SL. To do so, I investigated possible ways of providing artificial proprioceptive feedback using 2degrees of freedom (DoFs) tactile cues delivered through electrical stimulation and vibration. I designed a set of mappings that provide position cues from a virtual arm for each feedback modality. Two studies, one for each modality, were conducted. In the first study, I observed that the intensity of electrical stimulation affected its perception and comfort. I then found that it was easier to differentiate frequency variations than intensity variations. This study brings new insights into electrical stimulation perception and mapping design, considering comfort is rarely addressed in previous studies. In the second study, I compared two mappings, task space and joint space, for the feedback and control of a virtual arm. Although I did not observe any effect on the performance, I found that the task space mapping was preferred and better understood than the joint space mapping. Furthermore, a novel vibration feedback device was designed and tested to deliver 3DoFs position cues. The study showed that it is possible to transmit feedback at the torso and back, a location that few studies have considered. Moreover, this study proposes a novel strategy to provide 3DoFs feedback using vibration alone.Open Acces

Handwriting Correction System using Wearable Sleeve with Optimal Tactor Configuration

Handwriting remains an elusive skill with practice worksheets being the common method of learning. Since these worksheets provide only visual feedback and no quantitative feedback, it can often be a challenge to improve. For children with learning disabilities, learning handwriting skills is one of the most difficult tasks. We propose a handwriting training system that uses off-the-shelf webcam, a pen tracking software and a haptic sleeve which provides active feedback to the user based on their deviation from the original pattern. The sleeve has 4 individual motors that vibrate at different intensities based on the direction (right, left, up or down) and severity of the deviation (\u3c 1cm, 1cm – 3cm, \u3e 3cm). Different motor placements around the forearm are evaluated for vibro-tactile feedback accuracy and time response, and a novel spaced-ring configuration is proposed. This paper provides details on the system architecture and sleeve characterization, and the results show promise in utilizing the system for self-correction and visual-motor skills development. The results from sleeve characterization suggest the applicability of the spaced-ring configuration (perceived feedback accuracy \u3e 98%, time response \u3c 1s) in other vibrotactile hand guidance systems, in addition to handwriting correction. Recommendations on tactor placements around the forearm are provided

Spatially Distributed Tactile Feedback for Kinesthetic Motion Guidance

Apraxic stroke patients need to perform repetitive arm movements to regain motor functionality, but they struggle to process the visual feedback provided by typical virtual rehabilitation systems. Instead, we imagine a low cost sleeve that can measure the movement of the upper limb and provide tactile feedback at key locations. The feedback provided by the tactors should guide the patient through a series of desired movements by allowing him or her to feel limb configuration errors at each instant in time. After discussing the relevant motion capture and actuator options, this paper describes the design and programming of our current prototype, a wearable tactile interface that uses magnetic motion tracking and shaftless eccentric mass motors. The sensors and actuators are attached to the sleeve of an athletic shirt with novel plastic caps, which also help focus the vibration on the user\u27s skin. We connect the motors in current drive for improved performance, and we present a full parametric model for their in situ dynamic response (acceleration output given current input)

Quick-Glance and In-Depth exploration of a tabletop map for visually impaired people

National audienceInteractive tactile maps provide visually impaired people with accessible geographic information. However, when these maps are presented on large tabletops, tactile exploration without sight is long and tedious due to the size of the surface. In this paper we present a novel approach to speed up the process of exploring tabletop maps in the absence of vision. Our approach mimics the visual processing of a map and consists in two steps. First, the Quick-Glance step allows creating a global mental representation of the map by using mid-air gestures. Second, the In-Depth step allows users to reach Points of Interest with appropriate hand guidance onto the map. In this paper we present the design and development of a prototype combining a smartwatch and a tactile surface for Quick-Glance and In-Depth interactive exploration of a map

HapticHead - Augmenting Reality via Tactile Cues

Information overload is increasingly becoming a challenge in today's world. Humans have only a limited amount of attention to allocate between sensory channels and tend to miss or misjudge critical sensory information when multiple activities are going on at the same time. For example, people may miss the sound of an approaching car when walking across the street while looking at their smartphones. Some sensory channels may also be impaired due to congenital or acquired conditions. Among sensory channels, touch is often experienced as obtrusive, especially when it occurs unexpectedly. Since tactile actuators can simulate touch, targeted tactile stimuli can provide users of virtual reality and augmented reality environments with important information for navigation, guidance, alerts, and notifications. In this dissertation, a tactile user interface around the head is presented to relieve or replace a potentially impaired visual channel, called \emph{HapticHead}. It is a high-resolution, omnidirectional, vibrotactile display that presents general, 3D directional, and distance information through dynamic tactile patterns. The head is well suited for tactile feedback because it is sensitive to mechanical stimuli and provides a large spherical surface area that enables the display of precise 3D information and allows the user to intuitively rotate the head in the direction of a stimulus based on natural mapping. Basic research on tactile perception on the head and studies on various use cases of head-based tactile feedback are presented in this thesis. Several investigations and user studies have been conducted on (a) the funneling illusion and localization accuracy of tactile stimuli around the head, (b) the ability of people to discriminate between different tactile patterns on the head, (c) approaches to designing tactile patterns for complex arrays of actuators, (d) increasing the immersion and presence level of virtual reality applications, and (e) assisting people with visual impairments in guidance and micro-navigation. In summary, tactile feedback around the head was found to be highly valuable as an additional information channel in various application scenarios. Most notable is the navigation of visually impaired individuals through a micro-navigation obstacle course, which is an order of magnitude more accurate than the previous state-of-the-art, which used a tactile belt as a feedback modality. The HapticHead tactile user interface's ability to safely navigate people with visual impairments around obstacles and on stairs with a mean deviation from the optimal path of less than 6~cm may ultimately improve the quality of life for many people with visual impairments.Die Informationsüberlastung wird in der heutigen Welt zunehmend zu einer Herausforderung. Der Mensch hat nur eine begrenzte Menge an Aufmerksamkeit, die er zwischen den Sinneskanälen aufteilen kann, und neigt dazu, kritische Sinnesinformationen zu verpassen oder falsch einzuschätzen, wenn mehrere Aktivitäten gleichzeitig ablaufen. Zum Beispiel können Menschen das Geräusch eines herannahenden Autos überhören, wenn sie über die Straße gehen und dabei auf ihr Smartphone schauen. Einige Sinneskanäle können auch aufgrund von angeborenen oder erworbenen Erkrankungen beeinträchtigt sein. Unter den Sinneskanälen wird Berührung oft als aufdringlich empfunden, besonders wenn sie unerwartet auftritt. Da taktile Aktoren Berührungen simulieren können, können gezielte taktile Reize den Benutzern von Virtual- und Augmented Reality Anwendungen wichtige Informationen für die Navigation, Führung, Warnungen und Benachrichtigungen liefern. In dieser Dissertation wird eine taktile Benutzeroberfläche um den Kopf herum präsentiert, um einen möglicherweise beeinträchtigten visuellen Kanal zu entlasten oder zu ersetzen, genannt \emph{HapticHead}. Es handelt sich um ein hochauflösendes, omnidirektionales, vibrotaktiles Display, das allgemeine, 3D-Richtungs- und Entfernungsinformationen durch dynamische taktile Muster darstellt. Der Kopf eignet sich gut für taktiles Feedback, da er empfindlich auf mechanische Reize reagiert und eine große sphärische Oberfläche bietet, die die Darstellung präziser 3D-Informationen ermöglicht und es dem Benutzer erlaubt, den Kopf aufgrund der natürlichen Zuordnung intuitiv in die Richtung eines Reizes zu drehen. Grundlagenforschung zur taktilen Wahrnehmung am Kopf und Studien zu verschiedenen Anwendungsfällen von kopfbasiertem taktilem Feedback werden in dieser Arbeit vorgestellt. Mehrere Untersuchungen und Nutzerstudien wurden durchgeführt zu (a) der Funneling Illusion und der Lokalisierungsgenauigkeit von taktilen Reizen am Kopf, (b) der Fähigkeit von Menschen, zwischen verschiedenen taktilen Mustern am Kopf zu unterscheiden, (c) Ansätzen zur Gestaltung taktiler Muster für komplexe Arrays von Aktoren, (d) der Erhöhung des Immersions- und Präsenzgrades von Virtual-Reality-Anwendungen und (e) der Unterstützung von Menschen mit Sehbehinderungen bei der Führung und Mikronavigation. Zusammenfassend wurde festgestellt, dass taktiles Feedback um den Kopf herum als zusätzlicher Informationskanal in verschiedenen Anwendungsszenarien sehr wertvoll ist. Am interessantesten ist die Navigation von sehbehinderten Personen durch einen Mikronavigations-Hindernisparcours, welche um eine Größenordnung präziser ist als der bisherige Stand der Technik, der einen taktilen Gürtel als Feedback-Modalität verwendete. Die Fähigkeit der taktilen Benutzerschnittstelle HapticHead, Menschen mit Sehbehinderungen mit einer mittleren Abweichung vom optimalen Pfad von weniger als 6~cm sicher um Hindernisse und auf Treppen zu navigieren, kann letztendlich die Lebensqualität vieler Menschen mit Sehbehinderungen verbessern

Designing Tactile Interfaces for Abstract Interpersonal Communication, Pedestrian Navigation and Motorcyclists Navigation

The tactile medium of communication with users is appropriate for displaying information in situations where auditory and visual mediums are saturated. There are situations where a subject's ability to receive information through either of these channels is severely restricted by the environment they are in or through any physical impairments that the subject may have. In this project, we have focused on two groups of users who need sustained visual and auditory focus in their task: Soldiers on the battle field and motorcyclists. Soldiers on the battle field use their visual and auditory capabilities to maintain awareness of their environment to guard themselves from enemy assault. One of the major challenges to coordination in a hazardous environment is maintaining communication between team members while mitigating cognitive load. Compromise in communication between team members may result in mistakes that can adversely affect the outcome of a mission. We have built two vibrotactile displays, Tactor I and Tactor II, each with nine actuators arranged in a three-by-three matrix with differing contact areas that can represent a total of 511 shapes. We used two dimensions of tactile medium, shapes and waveforms, to represent verb phrases and evaluated ability of users to perceive verb phrases the tactile code. We evaluated the effectiveness of communicating verb phrases while the users were performing two tasks simultaneously. The results showed that performing additional visual task did not affect the accuracy or the time taken to perceive tactile codes. Another challenge in coordinating Soldiers on a battle field is navigating them to respective assembly areas. We have developed HaptiGo, a lightweight haptic vest that provides pedestrians both navigational intelligence and obstacle detection capabilities. HaptiGo consists of optimally-placed vibro-tactile sensors that utilize natural and small form factor interaction cues, thus emulating the sensation of being passively guided towards the intended direction. We evaluated HaptiGo and found that it was able to successfully navigate users with timely alerts of incoming obstacles without increasing cognitive load, thereby increasing their environmental awareness. Additionally, we show that users are able to respond to directional information without training. The needs of motorcyclists are di erent from those of Soldiers. Motorcyclists' need to maintain visual and auditory situational awareness at all times is crucial since they are highly exposed on the road. Route guidance systems, such as the Garmin, have been well tested on automobilists, but remain much less safe for use by motorcyclists. Audio/visual routing systems decrease motorcyclists' situational awareness and vehicle control, and thus increase the chances of an accident. To enable motorcyclists to take advantage of route guidance while maintaining situational awareness, we created HaptiMoto, a wearable haptic route guidance system. HaptiMoto uses tactile signals to encode the distance and direction of approaching turns, thus avoiding interference with audio/visual awareness. Evaluations show that HaptiMoto is intuitive for motorcyclists, and a safer alternative to existing solutions

Enhancing user experience and safety in the context of automated driving through uncertainty communication

Operators of highly automated driving systems may exhibit behaviour characteristic of overtrust issues due to an insufficient awareness of automation fallibility. Consequently, situation awareness in critical situations is reduced and safe driving performance following emergency takeovers is impeded. Previous research has indicated that conveying system uncertainties may alleviate these issues. However, existing approaches require drivers to attend the uncertainty information with focal attention, likely resulting in missed changes when engaged in non-driving-related tasks. This research project expands on existing work regarding uncertainty communication in the context of automated driving. Specifically, it aims to investigate the implications of conveying uncertainties under consideration of non-driving-related tasks and, based on the outcomes, develop and evaluate an uncertainty display that enhances both user experience and driving safety. In a first step, the impact of visually conveying uncertainties was investigated under consideration of workload, trust, monitoring behaviour, non-driving-related tasks, takeover performance, and situation awareness. For this, an anthropomorphic visual uncertainty display located in the instrument cluster was developed. While the hypothesised benefits for trust calibration and situation awareness were confirmed, the results indicate that visually conveying uncertainties leads to an increased perceived effort due to a higher frequency of monitoring glances. Building on these findings, peripheral awareness displays were explored as a means for conveying uncertainties without the need for focused attention to reduce monitoring glances. As a prerequisite for developing such a display, a systematic literature review was conducted to identify evaluation methods and criteria, which were then coerced into a comprehensive framework. Grounded in this framework, a peripheral awareness display for uncertainty communication was developed and subsequently compared with the initially proposed visual anthropomorphic uncertainty display in a driving simulator study. Eye tracking and subjective workload data indicate that the peripheral awareness display reduces the monitoring effort relative to the visual display, while driving performance and trust data highlight that the benefits of uncertainty communication are maintained. Further, this research project addresses the implications of increasing the functional detail of uncertainty information. Results of a driving simulator study indicate that particularly workload should be considered when increasing the functional detail of uncertainty information. Expanding upon this approach, an augmented reality display concept was developed and a set of visual variables was explored in a forced choice sorting task to assess their ordinal characteristics. Particularly changes in colour hue and animation-based variables received high preference ratings and were ordered consistently from low to high uncertainty. This research project has contributed a series of novel insights and ideas to the field of human factors in automated driving. It confirmed that conveying uncertainties improves trust calibration and situation awareness, but highlighted that using a visual display lessens the positive effects. Addressing this shortcoming, a peripheral awareness display was designed applying a dedicated evaluation framework. Compared with the previously employed visual display, it decreased monitoring glances and, consequentially, perceived effort. Further, an augmented reality-based uncertainty display concept was developed to minimise the workload increments associated with increases in the functional detail of uncertainty information.</div

Design and Development of a Multimodal Vest for Virtual Immersion and Guidance

This paper is focused on the development of a haptic vest to enhance immersion and realism in virtual environments, through vibrotactile feedback. The first steps to achieve touch-based communication are presented in order to set an actuation method based on vibration motors. Resulting vibrotactile patterns helping users to move inside virtual reality (VR). The research investigates human torso resolution and perception of vibration patterns, evaluating different kind of actuators at different locations on the vest. Finally, determining an appropriate distribution of vibration patterns allowed the generation of sensations that, for instance, help to guide in a mixed or virtual reality environment

In the dark – designing navigation for a haptic theatre experience

We describe the ongoing work of a collaborative theatre project, in which blind and sighted members of an interdisciplinary team are working on the creation of an immersive and accessible theatre experience. The theatre experience is set in pitch dark, and uses audio and haptic ubiquitous technologies to guide both blind and sighted members of the audience. During two sessions which explored the use of enactive navigation in the dark space, participants were able to locate areas of interest within the dark, using enactive explorative navigation, and some participants described this as a ‘dense’ experience