DragTapVib: An On-Skin Electromagnetic Drag, Tap, and Vibration Actuator for Wearable Computing

The skin, as the largest organ distributed all over the human body, offers excellent opportunities for different kinds of input stimuli. However, most of the haptic devices can only render single sensations or they need to combine multiple complex components for generating multiple sensations. We present “DragTapVib” in this paper, a novel, ultra-low-cost, wearable actuator that can reliably provide dragging, tapping, and vibrating sensations to the user. Our actuator is fully electromagnetically-actuated with a moving tactor that can render three haptic feedbacks through systematically controlling the current inside the flexible PCBs. The actuator can be arranged with varying parts of the body which enriches the potentials to implement promising application scenarios including delivering the notification and providing immersive haptic feedback either in virtual reality or in gameplay. A prototypical technical evaluation demonstrated the mechanical properties of our actuator. We quantitatively conducted a series of psychophysical user studies (N= 12) to reveal the feasibility of our prototype. The overall absolute identification study for distinguishing three sensations accuracy at two body locations reached up to 97.2%

Realistic Interaction with Virtual Objects within Arm's Reach

The automotive industry requires realistic virtual reality applications more than other domains to increase the efficiency of product development. Currently, the visual quality of virtual invironments resembles reality, but interaction within these environments is usually far from what is known in everyday life. Several realistic research approaches exist, however they are still not all-encompassing enough to be usable in industrial processes. This thesis realizes lifelike direct multi-hand and multi-finger interaction with arbitrary objects, and proposes algorithmic and technical improvements that also approach lifelike usability. In addition, the thesis proposes methods to measure the effectiveness and usability of such interaction techniques as well as discusses different types of grasping feedback that support the user during interaction. Realistic and reliable interaction is reached through the combination of robust grasping heuristics and plausible pseudophysical object reactions. The easy-to-compute grasping rules use the objects’ surface normals, and mimic human grasping behavior. The novel concept of Normal Proxies increases grasping stability and diminishes challenges induced by adverse normals. The intricate act of picking-up thin and tiny objects remains challenging for some users. These cases are further supported by the consideration of finger pinches, which are measured with a specialized finger tracking device. With regard to typical object constraints, realistic object motion is geometrically calculated as a plausible reaction on user input. The resulting direct finger-based interaction technique enables realistic and intuitive manipulation of arbitrary objects. The thesis proposes two methods that prove and compare effectiveness and usability. An expert review indicates that experienced users quickly familiarize themselves with the technique. A quantitative and qualitative user study shows that direct finger-based interaction is preferred over indirect interaction in the context of functional car assessments. While controller-based interaction is more robust, the direct finger-based interaction provides greater realism, and becomes nearly as reliable when the pinch-sensitive mechanism is used. At present, the haptic channel is not used in industrial virtual reality applications. That is why it can be used for grasping feedback which improves the users’ understanding of the grasping situation. This thesis realizes a novel pressure-based tactile feedback at the fingertips. As an alternative, vibro-tactile feedback at the same location is realized as well as visual feedback by the coloring of grasp-involved finger segments. The feedback approaches are also compared within the user study, which reveals that grasping feedback is a requirement to judge grasp status and that tactile feedback improves interaction independent of the used display system. The considerably stronger vibrational tactile feedback can quickly become annoying during interaction. The interaction improvements and hardware enhancements make it possible to interact with virtual objects in a realistic and reliable manner. By addressing realism and reliability, this thesis paves the way for the virtual evaluation of human-object interaction, which is necessary for a broader application of virtual environments in the automotive industry and other domains.Stärker als andere Branchen benötigt die Automobilindustrie realistische Virtual Reality Anwendungen für eine effiziente Produktentwicklung. Während sich die visuelle Qualität virtueller Darstellungen bereits der Realität angenähert hat, ist die Interaktion mit virtuellen Umgebungen noch weit vom täglichen Erleben der Menschen entfernt. Einige Forschungsansätze haben sich mit realistischer Interaktion befasst, gehen aber nicht weit genug, um in industriellen Prozessen eingesetzt zu werden. Diese Arbeit realisiert eine lebensnahe mehrhändige und fingerbasierte Interaktion mit beliebigen Objekten. Dabei ermöglichen algorithmische und technische Verbesserungen eine realitätsnahe Usability. Außerdem werden Methoden für die Evaluation dieser Interaktionstechnik vorgestellt und benutzerunterstützende Greiffeedbackarten diskutiert. Die verlässliche und gleichzeitig realistische Interaktion wird durch die Kombination von robusten Greifheuristiken und pseudophysikalischen Objektreaktionen erreicht. Die das menschliche Greifverhalten nachbildenden Greifregeln basieren auf den Oberflächennormalen der Objekte. Die Reduktion negativer Einflüsse verfälschter Normalen und eine höhere Griffstabilität werden durch das neuartige Konzept der Normal Proxies erreicht. Dennoch bleibt für manche Nutzer das Aufnehmen von dünnen und kleinen Objekten problematisch. Diese Fälle werden zusätzlich durch die Einbeziehung von Fingerberührungen unterstützt, die mit einem speziellen Fingertracking Gerät erfasst werden. Plausible Objektreaktionen auf Benutzereingaben werden unter Berücksichtigung typischer Objekteinschränkungen geometrisch berechnet. Die Arbeit schlägt zwei Methoden zur Evaluierung der fingerbasierten Interaktion vor. Ein Expertenreview zeigt, dass sich erfahrene Benutzer sehr schnell in die Technik einfinden. In einer Benutzerstudie wird nachgewiesen, dass fingerbasierte Interaktion im hier untersuchten Kontext vor indirekter Interaktion mit einem Eingabegerät bevorzugt wird. Während letztere robuster zu handhaben ist, stellt die fingerbasierte Interaktion einen deutlich höheren Realismus bereit und erreicht mit den vorgeschlagenen Verbesserungen eine vergleichbare Verlässlichkeit. Um Greifsituationen transparent zu gestalten, realisiert diese Arbeit ein neuartiges druckbasiertes taktiles Feedback an den Fingerspitzen. Alternativ wird ein vibrotaktiles Feedback am gleichen Ort realisiert und visuelles Feedback durch die Einfärbung der griffbeteiligten Fingersegmente umgesetzt. Die verschiedenen Feedbackansätze werden in der Benutzerstudie verglichen. Dabei wird Greiffeedback als Voraussetzung identifiziert, um den Greifzustand zu beurteilen. Taktiles Feedback verbessert dabei die Interaktion unabhängig vom eingesetzten Display. Das merklich stärkere Vibrationsfeedback kann während der Interaktion störend wirken. Die vorgestellten Interaktionsverbesserungen und Hardwareerweiterungen ermöglichen es, mit virtuellen Objekten auf realistische und zuverlässige Art zu interagieren. Indem die Arbeit Realismus und Verlässlichkeit gleichzeitig adressiert, bereitet sie den Boden für die virtuelle Untersuchung von Mensch-Objekt Interaktionen und ermöglicht so einen breiteren Einsatz virtueller Techniken in der Automobilindustrie und in anderen Bereichen

Realistic Interaction with Virtual Objects within Arm's Reach

The automotive industry requires realistic virtual reality applications more than other domains to increase the efficiency of product development. Currently, the visual quality of virtual invironments resembles reality, but interaction within these environments is usually far from what is known in everyday life. Several realistic research approaches exist, however they are still not all-encompassing enough to be usable in industrial processes. This thesis realizes lifelike direct multi-hand and multi-finger interaction with arbitrary objects, and proposes algorithmic and technical improvements that also approach lifelike usability. In addition, the thesis proposes methods to measure the effectiveness and usability of such interaction techniques as well as discusses different types of grasping feedback that support the user during interaction. Realistic and reliable interaction is reached through the combination of robust grasping heuristics and plausible pseudophysical object reactions. The easy-to-compute grasping rules use the objects’ surface normals, and mimic human grasping behavior. The novel concept of Normal Proxies increases grasping stability and diminishes challenges induced by adverse normals. The intricate act of picking-up thin and tiny objects remains challenging for some users. These cases are further supported by the consideration of finger pinches, which are measured with a specialized finger tracking device. With regard to typical object constraints, realistic object motion is geometrically calculated as a plausible reaction on user input. The resulting direct finger-based interaction technique enables realistic and intuitive manipulation of arbitrary objects. The thesis proposes two methods that prove and compare effectiveness and usability. An expert review indicates that experienced users quickly familiarize themselves with the technique. A quantitative and qualitative user study shows that direct finger-based interaction is preferred over indirect interaction in the context of functional car assessments. While controller-based interaction is more robust, the direct finger-based interaction provides greater realism, and becomes nearly as reliable when the pinch-sensitive mechanism is used. At present, the haptic channel is not used in industrial virtual reality applications. That is why it can be used for grasping feedback which improves the users’ understanding of the grasping situation. This thesis realizes a novel pressure-based tactile feedback at the fingertips. As an alternative, vibro-tactile feedback at the same location is realized as well as visual feedback by the coloring of grasp-involved finger segments. The feedback approaches are also compared within the user study, which reveals that grasping feedback is a requirement to judge grasp status and that tactile feedback improves interaction independent of the used display system. The considerably stronger vibrational tactile feedback can quickly become annoying during interaction. The interaction improvements and hardware enhancements make it possible to interact with virtual objects in a realistic and reliable manner. By addressing realism and reliability, this thesis paves the way for the virtual evaluation of human-object interaction, which is necessary for a broader application of virtual environments in the automotive industry and other domains.Stärker als andere Branchen benötigt die Automobilindustrie realistische Virtual Reality Anwendungen für eine effiziente Produktentwicklung. Während sich die visuelle Qualität virtueller Darstellungen bereits der Realität angenähert hat, ist die Interaktion mit virtuellen Umgebungen noch weit vom täglichen Erleben der Menschen entfernt. Einige Forschungsansätze haben sich mit realistischer Interaktion befasst, gehen aber nicht weit genug, um in industriellen Prozessen eingesetzt zu werden. Diese Arbeit realisiert eine lebensnahe mehrhändige und fingerbasierte Interaktion mit beliebigen Objekten. Dabei ermöglichen algorithmische und technische Verbesserungen eine realitätsnahe Usability. Außerdem werden Methoden für die Evaluation dieser Interaktionstechnik vorgestellt und benutzerunterstützende Greiffeedbackarten diskutiert. Die verlässliche und gleichzeitig realistische Interaktion wird durch die Kombination von robusten Greifheuristiken und pseudophysikalischen Objektreaktionen erreicht. Die das menschliche Greifverhalten nachbildenden Greifregeln basieren auf den Oberflächennormalen der Objekte. Die Reduktion negativer Einflüsse verfälschter Normalen und eine höhere Griffstabilität werden durch das neuartige Konzept der Normal Proxies erreicht. Dennoch bleibt für manche Nutzer das Aufnehmen von dünnen und kleinen Objekten problematisch. Diese Fälle werden zusätzlich durch die Einbeziehung von Fingerberührungen unterstützt, die mit einem speziellen Fingertracking Gerät erfasst werden. Plausible Objektreaktionen auf Benutzereingaben werden unter Berücksichtigung typischer Objekteinschränkungen geometrisch berechnet. Die Arbeit schlägt zwei Methoden zur Evaluierung der fingerbasierten Interaktion vor. Ein Expertenreview zeigt, dass sich erfahrene Benutzer sehr schnell in die Technik einfinden. In einer Benutzerstudie wird nachgewiesen, dass fingerbasierte Interaktion im hier untersuchten Kontext vor indirekter Interaktion mit einem Eingabegerät bevorzugt wird. Während letztere robuster zu handhaben ist, stellt die fingerbasierte Interaktion einen deutlich höheren Realismus bereit und erreicht mit den vorgeschlagenen Verbesserungen eine vergleichbare Verlässlichkeit. Um Greifsituationen transparent zu gestalten, realisiert diese Arbeit ein neuartiges druckbasiertes taktiles Feedback an den Fingerspitzen. Alternativ wird ein vibrotaktiles Feedback am gleichen Ort realisiert und visuelles Feedback durch die Einfärbung der griffbeteiligten Fingersegmente umgesetzt. Die verschiedenen Feedbackansätze werden in der Benutzerstudie verglichen. Dabei wird Greiffeedback als Voraussetzung identifiziert, um den Greifzustand zu beurteilen. Taktiles Feedback verbessert dabei die Interaktion unabhängig vom eingesetzten Display. Das merklich stärkere Vibrationsfeedback kann während der Interaktion störend wirken. Die vorgestellten Interaktionsverbesserungen und Hardwareerweiterungen ermöglichen es, mit virtuellen Objekten auf realistische und zuverlässige Art zu interagieren. Indem die Arbeit Realismus und Verlässlichkeit gleichzeitig adressiert, bereitet sie den Boden für die virtuelle Untersuchung von Mensch-Objekt Interaktionen und ermöglicht so einen breiteren Einsatz virtueller Techniken in der Automobilindustrie und in anderen Bereichen

Designing a New Tactile Display Technology and its Disability Interactions

People with visual impairments have a strong desire for a refreshable tactile interface that can provide immediate access to full page of Braille and tactile graphics. Regrettably, existing devices come at a considerable expense and remain out of reach for many. The exorbitant costs associated with current tactile displays stem from their intricate design and the multitude of components needed for their construction. This underscores the pressing need for technological innovation that can enhance tactile displays, making them more accessible and available to individuals with visual impairments. This research thesis delves into the development of a novel tactile display technology known as Tacilia. This technology's necessity and prerequisites are informed by in-depth qualitative engagements with students who have visual impairments, alongside a systematic analysis of the prevailing architectures underpinning existing tactile display technologies. The evolution of Tacilia unfolds through iterative processes encompassing conceptualisation, prototyping, and evaluation. With Tacilia, three distinct products and interactive experiences are explored, empowering individuals to manually draw tactile graphics, generate digitally designed media through printing, and display these creations on a dynamic pin array display. This innovation underscores Tacilia's capability to streamline the creation of refreshable tactile displays, rendering them more fitting, usable, and economically viable for people with visual impairments

Establishing a Framework for the development of Multimodal Virtual Reality Interfaces with Applicability in Education and Clinical Practice

The development of Virtual Reality (VR) and Augmented Reality (AR) content with multiple sources of both input and output has led to countless contributions in a great many number of fields, among which medicine and education. Nevertheless, the actual process of integrating the existing VR/AR media and subsequently setting it to purpose is yet a highly scattered and esoteric undertaking. Moreover, seldom do the architectures that derive from such ventures comprise haptic feedback in their implementation, which in turn deprives users from relying on one of the paramount aspects of human interaction, their sense of touch. Determined to circumvent these issues, the present dissertation proposes a centralized albeit modularized framework that thus enables the conception of multimodal VR/AR applications in a novel and straightforward manner. In order to accomplish this, the aforesaid framework makes use of a stereoscopic VR Head Mounted Display (HMD) from Oculus Rift©, a hand tracking controller from Leap Motion©, a custom-made VR mount that allows for the assemblage of the two preceding peripherals and a wearable device of our own design. The latter is a glove that encompasses two core modules in its innings, one that is able to convey haptic feedback to its wearer and another that deals with the non-intrusive acquisition, processing and registering of his/her Electrocardiogram (ECG), Electromyogram (EMG) and Electrodermal Activity (EDA). The software elements of the aforementioned features were all interfaced through Unity3D©, a powerful game engine whose popularity in academic and scientific endeavors is evermore increasing. Upon completion of our system, it was time to substantiate our initial claim with thoroughly developed experiences that would attest to its worth. With this premise in mind, we devised a comprehensive repository of interfaces, amid which three merit special consideration: Brain Connectivity Leap (BCL), Ode to Passive Haptic Learning (PHL) and a Surgical Simulator

Multimodal interaction: developing an interaction concept for a touchscreen incorporating tactile feedback

The touchscreen, as an alternative user interface for applications that normally require mice and keyboards, has become more and more commonplace, showing up on mobile devices, on vending machines, on ATMs and in the control panels of machines in industry, where conventional input devices cannot provide intuitive, rapid and accurate user interaction with the content of the display. The exponential growth in processing power on the PC, together with advances in understanding human communication channels, has had a significant effect on the design of usable, human-factored interfaces on touchscreens, and on the number and complexity of applications available on touchscreens. Although computer-driven touchscreen interfaces provide programmable and dynamic displays, the absence of the expected tactile cues on the hard and static surfaces of conventional touchscreens is challenging interface design and touchscreen usability, in particular for distracting, low-visibility environments. Current technology allows the human tactile modality to be used in touchscreens. While the visual channel converts graphics and text unidirectionally from the computer to the end user, tactile communication features a bidirectional information flow to and from the user as the user perceives and acts on the environment and the system responds to changing contextual information. Tactile sensations such as detents and pulses provide users with cues that make selecting and controlling a more intuitive process. Tactile features can compensate for deficiencies in some of the human senses, especially in tasks which carry a heavy visual or auditory burden. In this study, an interaction concept for tactile touchscreens is developed with a view to employing the key characteristics of the human sense of touch effectively and efficiently, especially in distracting environments where vision is impaired and hearing is overloaded. As a first step toward improving the usability of touchscreens through the integration of tactile effects, different mechanical solutions for producing motion in tactile touchscreens are investigated, to provide a basis for selecting suitable vibration directions when designing tactile displays. Building on these results, design know-how regarding tactile feedback patterns is further developed to enable dynamic simulation of UI controls, in order to give users a sense of perceiving real controls on a highly natural touch interface. To study the value of adding tactile properties to touchscreens, haptically enhanced UI controls are then further investigated with the aim of mapping haptic signals to different usage scenarios to perform primary and secondary tasks with touchscreens. The findings of the study are intended for consideration and discussion as a guide to further development of tactile stimuli, haptically enhanced user interfaces and touchscreen applications

Fine-grained Haptics: Sensing and Actuating Haptic Primary Colours (force, vibration, and temperature)

This thesis discusses the development of a multimodal, fine-grained visual-haptic system for teleoperation and robotic applications. This system is primarily composed of two complementary components: an input device known as the HaptiTemp sensor (combines “Haptics” and “Temperature”), which is a novel thermosensitive GelSight-like sensor, and an output device, an untethered multimodal finegrained haptic glove. The HaptiTemp sensor is a visuotactile sensor that can sense haptic primary colours known as force, vibration, and temperature. It has novel switchable UV markers that can be made visible using UV LEDs. The switchable markers feature is a real novelty of the HaptiTemp because it can be used in the analysis of tactile information from gel deformation without impairing the ability to classify or recognise images. The use of switchable markers in the HaptiTemp sensor is the solution to the trade-off between marker density and capturing high-resolution images using one sensor. The HaptiTemp sensor can measure vibrations by counting the number of blobs or pulses detected per unit time using a blob detection algorithm. For the first time, temperature detection was incorporated into a GelSight-like sensor, making the HaptiTemp sensor a haptic primary colours sensor. The HaptiTemp sensor can also do rapid temperature sensing with a 643 ms response time for the 31°C to 50°C temperature range. This fast temperature response of the HaptiTemp sensor is comparable to the withdrawal reflex response in humans. This is the first time a sensor can trigger a sensory impulse that can mimic a human reflex in the robotic community. The HaptiTemp sensor can also do simultaneous temperature sensing and image classification using a machine vision camera—the OpenMV Cam H7 Plus. This capability of simultaneous sensing and image classification has not been reported or demonstrated by any tactile sensor. The HaptiTemp sensor can be used in teleoperation because it can communicate or transmit tactile analysis and image classification results using wireless communication. The HaptiTemp sensor is the closest thing to the human skin in tactile sensing, tactile pattern recognition, and rapid temperature response. In order to feel what the HaptiTemp sensor is touching from a distance, a corresponding output device, an untethered multimodal haptic hand wearable, is developed to actuate the haptic primary colours sensed by the HaptiTemp sensor. This wearable can communicate wirelessly and has fine-grained cutaneous feedback to feel the edges or surfaces of the tactile images captured by the HaptiTemp sensor. This untethered multimodal haptic hand wearable has gradient kinesthetic force feedback that can restrict finger movements based on the force estimated by the HaptiTemp sensor. A retractable string from an ID badge holder equipped with miniservos that control the stiffness of the wire is attached to each fingertip to restrict finger movements. Vibrations detected by the HaptiTemp sensor can be actuated by the tapping motion of the tactile pins or by a buzzing minivibration motor. There is also a tiny annular Peltier device, or ThermoElectric Generator (TEG), with a mini-vibration motor, forming thermo-vibro feedback in the palm area that can be activated by a ‘hot’ or ‘cold’ signal from the HaptiTemp sensor. The haptic primary colours can also be embedded in a VR environment that can be actuated by the multimodal hand wearable. A VR application was developed to demonstrate rapid tactile actuation of edges, allowing the user to feel the contours of virtual objects. Collision detection scripts were embedded to activate the corresponding actuator in the multimodal haptic hand wearable whenever the tactile matrix simulator or hand avatar in VR collides with a virtual object. The TEG also gets warm or cold depending on the virtual object the participant has touched. Tests were conducted to explore virtual objects in 2D and 3D environments using Leap Motion control and a VR headset (Oculus Quest 2). Moreover, a fine-grained cutaneous feedback was developed to feel the edges or surfaces of a tactile image, such as the tactile images captured by the HaptiTemp sensor, or actuate tactile patterns in 2D or 3D virtual objects. The prototype is like an exoskeleton glove with 16 tactile actuators (tactors) on each fingertip, 80 tactile pins in total, made from commercially available P20 Braille cells. Each tactor can be controlled individually to enable the user to feel the edges or surfaces of images, such as the high-resolution tactile images captured by the HaptiTemp sensor. This hand wearable can be used to enhance the immersive experience in a virtual reality environment. The tactors can be actuated in a tapping manner, creating a distinct form of vibration feedback as compared to the buzzing vibration produced by a mini-vibration motor. The tactile pin height can also be varied, creating a gradient of pressure on the fingertip. Finally, the integration of the high-resolution HaptiTemp sensor, and the untethered multimodal, fine-grained haptic hand wearable is presented, forming a visuotactile system for sensing and actuating haptic primary colours. Force, vibration, and temperature sensing tests with corresponding force, vibration, and temperature actuating tests have demonstrated a unified visual-haptic system. Aside from sensing and actuating haptic primary colours, touching the edges or surfaces of the tactile images captured by the HaptiTemp sensor was carried out using the fine-grained cutaneous feedback of the haptic hand wearable