ABSTRACT
This chapter introduces an emerging research eld in augmented reality (AR), called haptic AR. As AR enables a real space to be transformed to a semi-virtual space by providing a user with the mixed sensations of real and virtual objects, haptic AR does the same for the sense of touch; a user can touch a real object, a virtual object, or a real object augmented with virtual touch. Visual AR is a relatively mature technology and is being applied to diverse practical applications such as surgical training, industrial manufacturing, and entertainment (Azuma et al. 2001). In contrast, the technology
10.1 Introduction .................................................................................................. 227 10.2 Taxonomies ................................................................................................... 229
10.2.1 Visuo-Haptic Reality-Virtuality Continuum ................................... 229 10.2.2 Articial Recreation and Augmented Perception ............................. 232 10.2.3 Within-and Between-Property Augmentation ................................. 233
10.3 Components Required for Haptic AR ..........................................................234 10.3.1 Interface for Haptic AR ....................................................................234 10.3.2 Registration between Real and Virtual Stimuli ................................ 236 10.3.3 Rendering Algorithm for Augmentation .......................................... 237 10.3.4 Models for Haptic AR....................................................................... 238
10.4 Stiffness Modulation..................................................................................... 239 10.4.1 Haptic AR Interface ..........................................................................240 10.4.2 Stiffness Modulation in Single-Contact Interaction .........................240 10.4.3 Stiffness Modulation in Two-Contact Squeezing ............................. 243
10.5 Application: Palpating Virtual Inclusion in Phantom with Two Contacts .....245 10.5.1 Rendering Algorithm ........................................................................ 247
10.6 Friction Modulation ......................................................................................248 10.7 Open Research Topics ..................................................................................249 10.8 Conclusions ...................................................................................................250 References .............................................................................................................. 251
for haptic AR is quite recent and poses a great number of new research problems ranging from modeling to rendering in terms of both hardware and software.
