Haptic interface control-design issues and experiments with a planar device

Describes the haptic rendering of a virtual environment by drawing upon concepts developed in the area of teleoperation. A four-channel teleoperation architecture is shown to be an effective means of coordinating the control of a 3-DOF haptic interface with the simulation of a virtual dynamic environmen

Interactive form creation: exploring the creation and manipulation of free form through the use of interactive multiple input interface

Most current CAD systems support only the two most common input devices: a mouse and a keyboard that impose a limit to the degree of interaction that a user can have with the system. However, it is not uncommon for users to work together on the same computer during a collaborative task. Beside that, people tend to use both hands to manipulate 3D objects; one hand is used to orient the object while the other hand is used to perform some operation on the object. The same things could be applied to computer modelling in the conceptual phase of the design process. A designer can rotate and position an object with one hand, and manipulate the shape [deform it] with the other hand. Accordingly, the 3D object can be easily and intuitively changed through interactive manipulation of both hands.The research investigates the manipulation and creation of free form geometries through the use of interactive interfaces with multiple input devices. First the creation of the 3D model will be discussed; several different types of models will be illustrated. Furthermore, different tools that allow the user to control the 3D model interactively will be presented. Three experiments were conducted using different interactive interfaces; two bi-manual techniques were compared with the conventional one-handed approach. Finally it will be demonstrated that the use of new and multiple input devices can offer many opportunities for form creation. The problem is that few, if any, systems make it easy for the user or the programmer to use new input devices

Doctor of Philosophy

dissertationHumans generally have difficulty performing precision tasks with their unsupported hands. To compensate for this difficulty, people often seek to support or rest their hand and arm on a fixed surface. However, when the precision task needs to be performed over a workspace larger than what can be reached from a fixed position, a fixed support is no longer useful. This dissertation describes the development of the Active Handrest, a device that expands its user's dexterous workspace by providing ergonomic support and precise repositioning motions over a large workspace. The prototype Active Handrest is a planar computer-controlled support for the user's hand and arm. The device can be controlled through force input from the user, position input from a grasped tool, or a combination of inputs. The control algorithm of the Active Handrest converts the input(s) into device motions through admittance control where the device's desired velocity is calculated proportionally to the input force or its equivalent. A robotic 2-axis admittance device was constructed as the initial Planar Active Handrest, or PAHR, prototype. Experiments were conducted to optimize the device's control input strategies. Large workspace shape tracing experiments were used to compare the PAHR to unsupported, fixed support, and passive moveable support conditions. The Active Handrest was found to reduce task error and provide better speedaccuracy performance. Next, virtual fixture strategies were explored for the device. From the options considered, a virtual spring fixture strategy was chosen based on its effectiveness. An experiment was conducted to compare the PAHR with its virtual fixture strategy to traditional virtual fixture techniques for a grasped stylus. Virtual fixtures implemented on the Active Handrest were found to be as effective as fixtures implemented on a grasped tool. Finally, a higher degree-of-freedom Enhanced Planar Active Handrest, or E-PAHR, was constructed to provide support for large workspace precision tasks while more closely following the planar motions of the human arm. Experiments were conducted to investigate appropriate control strategies and device utility. The E-PAHR was found to provide a skill level equal to that of the PAHR with reduced user force input and lower perceived exertion

Contactless Haptic Display Through Magnetic Field Control

Haptic rendering enables people to touch, perceive, and manipulate virtual objects in a virtual environment. Using six cascaded identical hollow disk electromagnets and a small permanent magnet attached to an operator's finger, this paper proposes and develops an untethered haptic interface through magnetic field control. The concentric hole inside the six cascaded electromagnets provides the workspace, where the 3D position of the permanent magnet is tracked with a Microsoft Kinect sensor. The driving currents of six cascaded electromagnets are calculated in real-time for generating the desired magnetic force. Offline data from an FEA (finite element analysis) based simulation, determines the relationship between the magnetic force, the driving currents, and the position of the permanent magnet. A set of experiments including the virtual object recognition experiment, the virtual surface identification experiment, and the user perception evaluation experiment were conducted to demonstrate the proposed system, where Microsoft HoloLens holographic glasses are used for visual rendering. The proposed magnetic haptic display leads to an untethered and non-contact interface for natural haptic rendering applications, which overcomes the constraints of mechanical linkages in tool-based traditional haptic devices

Measuring user experience for virtual reality

In recent years, Virtual Reality (VR) and 3D User Interfaces (3DUI) have seen a drastic increase in popularity, especially in terms of consumer-ready hardware and software. These technologies have the potential to create new experiences that combine the advantages of reality and virtuality. While the technology for input as well as output devices is market ready, only a few solutions for everyday VR - online shopping, games, or movies - exist, and empirical knowledge about performance and user preferences is lacking. All this makes the development and design of human-centered user interfaces for VR a great challenge. This thesis investigates the evaluation and design of interactive VR experiences. We introduce the Virtual Reality User Experience (VRUX) model based on VR-specific external factors and evaluation metrics such as task performance and user preference. Based on our novel UX evaluation approach, we contribute by exploring the following directions: shopping in virtual environments, as well as text entry and menu control in the context of everyday VR. Along with this, we summarize our findings by design spaces and guidelines for choosing optimal interfaces and controls in VR.In den letzten Jahren haben Virtual Reality (VR) und 3D User Interfaces (3DUI) stark an Popularität gewonnen, insbesondere bei Hard- und Software im Konsumerbereich. Diese Technologien haben das Potenzial, neue Erfahrungen zu schaffen, die die Vorteile von Realität und Virtualität kombinieren. Während die Technologie sowohl für Eingabe- als auch für Ausgabegeräte marktreif ist, existieren nur wenige Lösungen für den Alltag in VR - wie Online-Shopping, Spiele oder Filme - und es fehlt an empirischem Wissen über Leistung und Benutzerpräferenzen. Dies macht die Entwicklung und Gestaltung von benutzerzentrierten Benutzeroberflächen für VR zu einer großen Herausforderung. Diese Arbeit beschäftigt sich mit der Evaluation und Gestaltung von interaktiven VR-Erfahrungen. Es wird das Virtual Reality User Experience (VRUX)- Modell eingeführt, das auf VR-spezifischen externen Faktoren und Bewertungskennzahlen wie Leistung und Benutzerpräferenz basiert. Basierend auf unserem neuartigen UX-Evaluierungsansatz leisten wir einen Beitrag, indem wir folgende interaktive Anwendungsbereiche untersuchen: Einkaufen in virtuellen Umgebungen sowie Texteingabe und Menüsteuerung im Kontext des täglichen VR. Die Ergebnisse werden außerdem mittels Richtlinien zur Auswahl optimaler Schnittstellen in VR zusammengefasst