11,403 research outputs found
Doctor of Philosophy
dissertationVirtual environments provide a consistent and relatively inexpensive method of training individuals. They often include haptic feedback in the form of forces applied to a manipulandum or thimble to provide a more immersive and educational experience. However, the limited haptic feedback provided in these systems tends to be restrictive and frustrating to use. Providing tactile feedback in addition to this kinesthetic feedback can enhance the user's ability to manipulate and interact with virtual objects while providing a greater level of immersion. This dissertation advances the state-of-the-art by providing a better understanding of tactile feedback and advancing combined tactilekinesthetic systems. The tactile feedback described within this dissertation is provided by a finger-mounted device called the contact location display (CLD). Rather than displaying the entire contact surface, the device displays (feeds back) information only about the center of contact between the user's finger and a virtual surface. In prior work, the CLD used specialized two-dimensional environments to provide smooth tactile feedback. Using polygonal environments would greatly enhance the device's usefulness. However, the surface discontinuities created by the facets on these models are rendered through the CLD, regardless of traditional force shading algorithms. To address this issue, a haptic shading algorithm was developed to provide smooth tactile and kinesthetic interaction with general polygonal models. Two experiments were used to evaluate the shading algorithm. iv To better understand the design requirements of tactile devices, three separate experiments were run to evaluate the perception thresholds for cue localization, backlash, and system delay. These experiments establish quantitative design criteria for tactile devices. These results can serve as the maximum (i.e., most demanding) device specifications for tactile-kinesthetic haptic systems where the user experiences tactile feedback as a function of his/her limb motions. Lastly, a revision of the CLD was constructed and evaluated. By taking the newly evaluated design criteria into account, the CLD device became smaller and lighter weight, while providing a full two degree-of-freedom workspace that covers the bottom hemisphere of the finger. Two simple manipulation experiments were used to evaluate the new CLD device
Pseudo-haptics survey: Human-computer interaction in extended reality & teleoperation
Pseudo-haptic techniques are becoming increasingly popular in human-computer interaction. They replicate haptic sensations by leveraging primarily visual feedback rather than mechanical actuators. These techniques bridge the gap between the real and virtual worlds by exploring the brain’s ability to integrate visual and haptic information. One of the many advantages of pseudo-haptic techniques is that they are cost-effective, portable, and flexible. They eliminate the need for direct attachment of haptic devices to the body, which can be heavy and large and require a lot of power and maintenance. Recent research has focused on applying these techniques to extended reality and mid-air interactions. To better understand the potential of pseudo-haptic techniques, the authors developed a novel taxonomy encompassing tactile feedback, kinesthetic feedback, and combined categories in multimodal approaches, ground not covered by previous surveys. This survey highlights multimodal strategies and potential avenues for future studies, particularly regarding integrating these techniques into extended reality and collaborative virtual environments.info:eu-repo/semantics/publishedVersio
Analysis and Observations from the First Amazon Picking Challenge
This paper presents a overview of the inaugural Amazon Picking Challenge
along with a summary of a survey conducted among the 26 participating teams.
The challenge goal was to design an autonomous robot to pick items from a
warehouse shelf. This task is currently performed by human workers, and there
is hope that robots can someday help increase efficiency and throughput while
lowering cost. We report on a 28-question survey posed to the teams to learn
about each team's background, mechanism design, perception apparatus, planning
and control approach. We identify trends in this data, correlate it with each
team's success in the competition, and discuss observations and lessons learned
based on survey results and the authors' personal experiences during the
challenge
Doctor of Philosophy
dissertationVirtual reality is becoming a common technology with applications in fields such as medical training, product development, and entertainment. Providing haptic (sense of touch) information along with visual and audio information can create an immersive vi
Tactile Weight Rendering: A Review for Researchers and Developers
Haptic rendering of weight plays an essential role in naturalistic object
interaction in virtual environments. While kinesthetic devices have
traditionally been used for this aim by applying forces on the limbs, tactile
interfaces acting on the skin have recently offered potential solutions to
enhance or substitute kinesthetic ones. Here, we aim to provide an in-depth
overview and comparison of existing tactile weight rendering approaches. We
categorized these approaches based on their type of stimulation into asymmetric
vibration and skin stretch, further divided according to the working mechanism
of the devices. Then, we compared these approaches using various criteria,
including physical, mechanical, and perceptual characteristics of the reported
devices and their potential applications. We found that asymmetric vibration
devices have the smallest form factor, while skin stretch devices relying on
the motion of flat surfaces, belts, or tactors present numerous mechanical and
perceptual advantages for scenarios requiring more accurate weight rendering.
Finally, we discussed the selection of the proposed categorization of devices
and their application scopes, together with the limitations and opportunities
for future research. We hope this study guides the development and use of
tactile interfaces to achieve a more naturalistic object interaction and
manipulation in virtual environments.Comment: 15 pages, 2 tables, 3 figures, surve
On Neuromechanical Approaches for the Study of Biological Grasp and Manipulation
Biological and robotic grasp and manipulation are undeniably similar at the
level of mechanical task performance. However, their underlying fundamental
biological vs. engineering mechanisms are, by definition, dramatically
different and can even be antithetical. Even our approach to each is
diametrically opposite: inductive science for the study of biological systems
vs. engineering synthesis for the design and construction of robotic systems.
The past 20 years have seen several conceptual advances in both fields and the
quest to unify them. Chief among them is the reluctant recognition that their
underlying fundamental mechanisms may actually share limited common ground,
while exhibiting many fundamental differences. This recognition is particularly
liberating because it allows us to resolve and move beyond multiple paradoxes
and contradictions that arose from the initial reasonable assumption of a large
common ground. Here, we begin by introducing the perspective of neuromechanics,
which emphasizes that real-world behavior emerges from the intimate
interactions among the physical structure of the system, the mechanical
requirements of a task, the feasible neural control actions to produce it, and
the ability of the neuromuscular system to adapt through interactions with the
environment. This allows us to articulate a succinct overview of a few salient
conceptual paradoxes and contradictions regarding under-determined vs.
over-determined mechanics, under- vs. over-actuated control, prescribed vs.
emergent function, learning vs. implementation vs. adaptation, prescriptive vs.
descriptive synergies, and optimal vs. habitual performance. We conclude by
presenting open questions and suggesting directions for future research. We
hope this frank assessment of the state-of-the-art will encourage and guide
these communities to continue to interact and make progress in these important
areas
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