Haptic Rendering: Foundations, Algorithms and Applications
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For a long time, human beings have dreamed of a virtual world where it is possible to interact with synthetic entities as if they were real. It has been shown that the ability to touch virtual objects increases the sense of presence in virtual environments. This book provides an authoritative overview of state-of-theart haptic rendering algorithms and their applications. The authors examine various approaches and techniques for designing touch-enabled interfaces for a number of applications, including medical training, model design, and maintainability analysis for virtual prototyping, scientific visualization, and creative processes.
expected to be ventriloquized spatially toward the location of the incongruent visual distractor [Bertelson and de Gelder 04]. When the visual distractor is placed at a diﬀerent elevation from the vibrotactile target, but still close to it (i.e., on the same hand), the latter may be mislocalized toward the former. Such spatial ventriloquism, should it occur, might lead to errors in participants’ responses, or simply to their ﬁnding it harder (and therefore taking more time) to discriminate the
we rate the thermal resistance of the coil as 7.5◦ /W. A time constant of 160 s was determined for the actuator. The thermal model can be used for open loop tracking of device temperature to ensure operation within thermal limits. Embedded Sensors. In the new device, miniature interferometric optical encoders from Micro-E Inc. were integrated inside to allow the ﬁngers close ✐ ✐ ✐ ✐ ✐ ✐ ✐ ✐ 4.3. Design of a Multifinger Haptic Device 73 140 100 o temperature | C| 120 80 60 40
explored the surface with a bare ﬁnger, with a ﬁxed mechanical ﬁlter between the drum and the ﬁnger to eliminate shear forces, and with a mechanical ﬁlter free to ﬂoat. The subject performance dropped signiﬁcantly when the shear forces were masked with the ﬁxed mechanical ﬁlter. Taken together, these studies underscore the importance of ﬁngerpad shear forces in texture perception, but do not indicate whether shear force modulation alone would be suﬃcient to display texture. 6.2 Friction
only positive (left-to-right) forces; negative forces were recorded as zero. Because data was collected continually throughout each trial, the relevant normal and friction force data needed to be deciphered. Relevant data was extracted by placing thresholds (Figure 6.22) on both ﬁnger velocity and friction force. Data points were neglected if the ﬁnger velocity was less than 20.3 mm/s (0.8 in/s). This threshold ensured that we were measuring kinematic, rather than static, friction and also helped
Klatzky and S. Lederman When people interact with objects in the world using their sense of touch, contact is often made with a tool. We use a key to open a door, a pencil to write on paper, or a spoon to stir a pot. As David Katz [Katz 25] observed, under these circumstances our phenomenology—our immediate experience of the world—concerns the touched surface, not the tool, which in some sense is transparent to the act of touching. The issues addressed in this chapter begin with this