20,728 research outputs found
Tactile Mapping and Localization from High-Resolution Tactile Imprints
This work studies the problem of shape reconstruction and object localization
using a vision-based tactile sensor, GelSlim. The main contributions are the
recovery of local shapes from contact, an approach to reconstruct the tactile
shape of objects from tactile imprints, and an accurate method for object
localization of previously reconstructed objects. The algorithms can be applied
to a large variety of 3D objects and provide accurate tactile feedback for
in-hand manipulation. Results show that by exploiting the dense tactile
information we can reconstruct the shape of objects with high accuracy and do
on-line object identification and localization, opening the door to reactive
manipulation guided by tactile sensing. We provide videos and supplemental
information in the project's website
http://web.mit.edu/mcube/research/tactile_localization.html.Comment: ICRA 2019, 7 pages, 7 figures. Website:
http://web.mit.edu/mcube/research/tactile_localization.html Video:
https://youtu.be/uMkspjmDbq
Active End-Effector Pose Selection for Tactile Object Recognition through Monte Carlo Tree Search
This paper considers the problem of active object recognition using touch
only. The focus is on adaptively selecting a sequence of wrist poses that
achieves accurate recognition by enclosure grasps. It seeks to minimize the
number of touches and maximize recognition confidence. The actions are
formulated as wrist poses relative to each other, making the algorithm
independent of absolute workspace coordinates. The optimal sequence is
approximated by Monte Carlo tree search. We demonstrate results in a physics
engine and on a real robot. In the physics engine, most object instances were
recognized in at most 16 grasps. On a real robot, our method recognized objects
in 2--9 grasps and outperformed a greedy baseline.Comment: Accepted to International Conference on Intelligent Robots and
Systems (IROS) 201
Active End-Effector Pose Selection for Tactile Object Recognition through Monte Carlo Tree Search
This paper considers the problem of active object recognition using touch
only. The focus is on adaptively selecting a sequence of wrist poses that
achieves accurate recognition by enclosure grasps. It seeks to minimize the
number of touches and maximize recognition confidence. The actions are
formulated as wrist poses relative to each other, making the algorithm
independent of absolute workspace coordinates. The optimal sequence is
approximated by Monte Carlo tree search. We demonstrate results in a physics
engine and on a real robot. In the physics engine, most object instances were
recognized in at most 16 grasps. On a real robot, our method recognized objects
in 2--9 grasps and outperformed a greedy baseline.Comment: Accepted to International Conference on Intelligent Robots and
Systems (IROS) 201
More than skin deep: body representation beyond primary somatosensory cortex
The neural circuits underlying initial sensory processing of somatic information are relatively well understood. In contrast, the processes that go beyond primary somatosensation to create more abstract representations related to the body are less clear. In this review, we focus on two classes of higher-order processing beyond somatosensation. Somatoperception refers to the process of perceiving the body itself, and particularly of ensuring somatic perceptual constancy. We review three key elements of somatoperception: (a) remapping information from the body surface into an egocentric reference frame (b) exteroceptive perception of objects in the external world through their contact with the body and (c) interoceptive percepts about the nature and state of the body itself. Somatorepresentation, in contrast, refers to the essentially cognitive process of constructing semantic knowledge and attitudes about the body, including: (d) lexical-semantic knowledge about bodies generally and one’s own body specifically, (e) configural knowledge about the structure of bodies, (f) emotions and attitudes directed towards one’s own body, and (g) the link between physical body and psychological self. We review a wide range of neuropsychological, neuroimaging and neurophysiological data to explore the dissociation between these different aspects of higher somatosensory function
Realtime State Estimation with Tactile and Visual sensing. Application to Planar Manipulation
Accurate and robust object state estimation enables successful object
manipulation. Visual sensing is widely used to estimate object poses. However,
in a cluttered scene or in a tight workspace, the robot's end-effector often
occludes the object from the visual sensor. The robot then loses visual
feedback and must fall back on open-loop execution.
In this paper, we integrate both tactile and visual input using a framework
for solving the SLAM problem, incremental smoothing and mapping (iSAM), to
provide a fast and flexible solution. Visual sensing provides global pose
information but is noisy in general, whereas contact sensing is local, but its
measurements are more accurate relative to the end-effector. By combining them,
we aim to exploit their advantages and overcome their limitations. We explore
the technique in the context of a pusher-slider system. We adapt iSAM's
measurement cost and motion cost to the pushing scenario, and use an
instrumented setup to evaluate the estimation quality with different object
shapes, on different surface materials, and under different contact modes
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