Ambient Haptic Systems

AMBIENT systems employ devices that are seamlessly integrated in a user’s environment, providing unobtrusive and interactive access to digital media. These devices, when networked in systems of sensors, actuators, and computational units, can support intelligent, adaptive machine behavior. Haptics, as a naturally interactive communication modality, has an important and indispensable role to play in the evolution of user-centered interfaces. The haptic modality is largely untapped, while the vision and auditory modalities are often saturated. The advent of sophisticated haptic interfaces and tangible interfaces makes it possible to employ haptics in ubiquitous and veridical interactions between people and technology, or between people and people, providing supplementary and complementary information from a separate information channel. As a result, we see an explosion of applications of haptics in vehicle cockpits with clear benefits for safety; more effective portable information and communication devices; rethought and retooled sensory substitution systems for adaptive technologies and accessibility; games in homes and in public places; home automation (domotics) with benefits for energy conservation; improved public furniture with better user interfaces; office equipment and engineering workstations; ambient interfaces to virtual worlds; medical devices evolving toward greater safety and accuracy; interactive museums; home appliances; emerging technologies for home assisted living; advanced prosthetics, etc. This special issue is about the art and the science of haptics in such situations. It aims at providing a broad overview of the field through an introductory article as well as a collection of focused research studies in the area of ambient haptic systems. The featured articles span several application domains and make important contributions to ambient haptics. The opening article by Karon E. MacLean provides an introduction to ambient interfaces and the applicability of haptic interfaces in ambient interfaces. The article discusses the virtues, challenges, and opportunities of employing the haptic modality in truly ubiquitous interfaces that engage humans in a multimodal manner. Researchers in ambient haptic systems will be able to use the examples cited in the article as well as the design principles that are dicussed as the basis for future research. The second article by Antal Haans and Wijnand A. IJsselsteijn introduces the notion of “virtual Midas touch.” Based on the phenomenon of inducing conciliatory behavior through subtle touch on the arm, the paper presents an automated system to provide haptic signals through a vibrotactile arm band to induce a similar affective response. This paper aims to exploit the intimate relation between affect and haptics and provides a design example of a haptic ambient system though a combination of qualitative and quantitative analysis for validation. The third article, authored by Annie Rydström, Robert Broström, and Peter Bengtsson describes an experiment to functionally test a haptic interface in a car. Driving is a complex activity requiring significant amount of visual and auditory resources. Well-designed ambient haptic systems can provide intuitive interaction. The methodology for design and evaluation of in-car haptic interfaces has therefore become an active research area. This paper focuses on the applicability of knob-based haptic interface to different types of tasks while driving and provides designers with valuable information on what type of tasks may or may not be performed efficiently with haptic sensations. Yon Visell, Alvin Law, and Jeremy R. Cooperstock present their work on novel research direction of using floor surfaces as haptic interfaces in an ambient manner in the fourth article. Sensations arising from interaction with the floor that are sensed by feet are essential during locomotion and balancing. However, sensations from the floor can also be used for interaction. The authors present a system to provide ambient information through a floorbased ambient haptic system, which leads a trend toward going beyond the hand to interact meaningfully with haptic interfaces. Audio-haptic ambient interfaces are poised to play an important role in the development of ubiquitous environments. The paper by Maria Karam, Frank A. Russo, and Deborah I. Fels uses the general principle of sensory substitution to develop a cross modal audio-haptic system able to represent music through a haptic interface embedded in a chair. Sensory substitution has been around since the 1920s but many of its possibilities are still untapped. This paper presents a model that aims to sense content, structure, and affective dimension of music and present it through a haptic interface. Michael Strolz, Alexander Mörtl, Michael Gräf, and Martin Buss describe a system that uses haptics to control an automated car door. Automated car doors can provide IEEE TRANSACTIONS ON HAPTICS, VOL. 2, NO. 3, JULY-SEPTEMBER 2009 121