haptic

In this paper we present a system for providing tactile feedback for stylus-based touch-screen displays. The Haptic Pen is a simple low-cost device that provides individualized tactile feedback for multiple simultaneous users and can operate on large touch screens as well as ordinary surfaces. A pressure-sensitive stylus is combined with a small solenoid to generate a wide range of tactile sensations. The physical sensations generated by the Haptic pen can be used to enhance our existing interaction with graphical user interfaces as well as to help make modern computing systems more accessible to those with visual or motor impairments.

We introduce a set of techniques for haptically manipulating digital media such as video, audio, voicemail and computer graphics, utilizing virtual mediating dynamic models based on intuitive physical metaphors. For example, a video sequence can be modeled by linking its motion to a heavy spinning virtual wheel: the user browses by grasping a physical force-feedback knob and engaging the virtual wheel through a simulated clutch to spin or brake it, while feeling the passage of individual frames. These systems were implemented on a collection of single axis actuated displays (knobs and sliders), equipped with orthogonal force sensing to enhance their expressive potential. We demonstrate how continuous interaction through a haptically actuated device rather than discrete button and key presses can produce simple yet powerful tools that leverage physical intuition.

We present a survey of design issues for developing effective free-space three-dimensional (3D) user interfaces. Our survey is based upon previous work in 3D interaction, our experience in developing free-space interfaces, and our informal observations of test users. We illustrate our design issues using examples drawn from instances of 3D interfaces.

For example, our first issue suggests that users have difficulty understanding three-dimensional space. We offer a set of strategies which may help users to better perceive a 3D virtual environment, including the use of spatial references, relative gesture, two-handed interaction, multisensory feedback, physical constraints, and head tracking. We describe interfaces which employ these strategies.

Our major contribution is the synthesis of many scattered results, observations, and examples into a common framework. This framework should serve as a guide to researchers or systems builders who may not be familiar with design issues in spatial input. Where appropriate, we also try to identify areas in free-space 3D interaction which we see as likely candidates for additional research.

An extended and annotated version of the references list for this paper is available on-line through mosaic at address http://uvacs.cs.virginia.edu/~kph2q/.

We present the Haptic Shading Framework (HSF), a framework for procedurally defining haptic texture. HSF haptic texture shaders are short procedures allowing an application-programmer to easily define interesting haptic surface interaction and the parameters that control the surface properties. These shaders provide the illusion of surface characteristics by altering previously calculated forces from object collision in the haptic pipeline.HSF can be used in an existing haptic application with few modifications. The framework consists of user-programmable modules that are dynamically loaded. This framework and all user-defined procedures are written in C++, with a provided library of useful math and geometry functions. These functions are meant to mimic RenderMan functionality, creating a familiar shading environment. As we demonstrate, many procedural shading methods and algorithms can be directly adopted for haptic shading.

In this paper, we present a methodology for recognizing seatedpostures using data from pressure sensors installed on a chair.Information about seated postures could be used to help avoidadverse effects of sitting for long periods of time or to predictseated activities for a human-computer interface. Our system designdisplays accurate near-real-time classification performance on datafrom subjects on which the posture recognition system was nottrained by using a set of carefully designed, subject-invariantsignal features. By using a near-optimal sensor placement strategy,we keep the number of required sensors low thereby reducing costand computational complexity. We evaluated the performance of ourtechnology using a series of empirical methods including (1)cross-validation (classification accuracy of 87% for ten posturesusing data from 31 sensors), and (2) a physical deployment of oursystem (78% classification accuracy using data from 19sensors).

We present the Haptic Shading Framework (HSF), a framework for procedurally defining haptic texture. HSF haptic texture shaders are short procedures allowing an application-programmer to easily define interesting haptic surface interaction and the parameters that control the surface properties. These shaders provide the illusion of surface characteristics by altering previously calculated forces from object collision in the haptic pipeline.HSF can be used in an existing haptic application with few modifications. The framework consists of user-programmable modules that are dynamically loaded. This framework and all user-defined procedures are written in C++, with a provided library of useful math and geometry functions. These functions are meant to mimic RenderMan functionality, creating a familiar shading environment. As we demonstrate, many procedural shading methods and algorithms can be directly adopted for haptic shading.

We present a range of novel interactions enabled by a simple modification in the design of a computer mouse. By converting each mouse button to pop through tactile push-buttons, similar to the focus/shutter-release buttons used in many cameras, users can feel, and the computer can sense, two distinct "clicks" corresponding to pressing lightly and pressing firmly to pop through. Despite the prototypical status of our hardware and software implementations, our current pop through mouse interactions are compelling and warrant further investigation. In particular, we demonstrate that pop through buttons not only yield an additional button activation state that is composable with, or even preferable to, techniques such as double-clicking, but also can endow a qualitatively novel user experience when meaningfully and consistently applied. We propose a number of software guidelines that may provide a consistent, systemic benefit; for example, light pressure may invoke default interaction (short menu), and firm pressure may supply more detail (long menu).

In this paper, we show how traditional physical interface components such as switches, levers, knobs and touch screens can be easily modified to identify who is activating each control. This allows us to change the function per-formed by the control, and the sensory feedback provided by the control itself, dependent upon the user. An auditing function is also available that logs each user's actions. We describe a number of example usage scenarios for our tech-nique, and present two sample implementations.

We present the Haptic Shading Framework (HSF), a framework for procedurally defining haptic texture. HSF haptic texture shaders are short procedures allowing an application-programmer to easily define interesting haptic surface interaction and the parameters that control the surface properties. These shaders provide the illusion of surface characteristics by altering previously calculated forces from object collision in the haptic pipeline.HSF can be used in an existing haptic application with few modifications. The framework consists of user-programmable modules that are dynamically loaded. This framework and all user-defined procedures are written in C++, with a provided library of useful math and geometry functions. These functions are meant to mimic RenderMan functionality, creating a familiar shading environment. As we demonstrate, many procedural shading methods and algorithms can be directly adopted for haptic shading.