231 research outputs found
(alpha + gamma) Ultrafine duplex structure formation in twophase stainless steel by high-pressure torsion and annealing
Tactile-Filter: Interactive Tactile Perception for Part Mating
Humans rely on touch and tactile sensing for a lot of dexterous manipulation
tasks. Our tactile sensing provides us with a lot of information regarding
contact formations as well as geometric information about objects during any
interaction. With this motivation, vision-based tactile sensors are being
widely used for various robotic perception and control tasks. In this paper, we
present a method for interactive perception using vision-based tactile sensors
for a part mating task, where a robot can use tactile sensors and a feedback
mechanism using a particle filter to incrementally improve its estimate of
objects (pegs and holes) that fit together. To do this, we first train a deep
neural network that makes use of tactile images to predict the probabilistic
correspondence between arbitrarily shaped objects that fit together. The
trained model is used to design a particle filter which is used twofold. First,
given one partial (or non-unique) observation of the hole, it incrementally
improves the estimate of the correct peg by sampling more tactile observations.
Second, it selects the next action for the robot to sample the next touch (and
thus image) which results in maximum uncertainty reduction to minimize the
number of interactions during the perception task. We evaluate our method on
several part-mating tasks with novel objects using a robot equipped with a
vision-based tactile sensor. We also show the efficiency of the proposed action
selection method against a naive method. See supplementary video at
https://www.youtube.com/watch?v=jMVBg_e3gLw .Comment: Accepted at RSS202
Tactile Estimation of Extrinsic Contact Patch for Stable Placement
Precise perception of contact interactions is essential for the fine-grained
manipulation skills for robots. In this paper, we present the design of
feedback skills for robots that must learn to stack complex-shaped objects on
top of each other. To design such a system, a robot should be able to reason
about the stability of placement from very gentle contact interactions. Our
results demonstrate that it is possible to infer the stability of object
placement based on tactile readings during contact formation between the object
and its environment. In particular, we estimate the contact patch between a
grasped object and its environment using force and tactile observations to
estimate the stability of the object during a contact formation. The contact
patch could be used to estimate the stability of the object upon the release of
the grasp. The proposed method is demonstrated on various pairs of objects that
are used in a very popular board game.Comment: Under submissio
Experimental Study of a Novel Method of Cardiopulmonary Resuscitation Using a Combination of Percutaneous Cardiopulmonary Support and Liposome-encapsulated Hemoglobin (TRM645)
Percutaneous cardiopulmonary support (PCPS) has been applied for cardiopulmonary arrest (CPA). We have developed a novel method of cardiopulmonary resuscitation using PCPS combined with liposome-encapsulated hemoglobin (TRM645) to improve oxygen delivery to vital organs. Ventricular fibrillation was electrically induced to an adult goat for 10 min. Next, PCPS (30 ml/kg/min, V/Q: 1) was performed for 20 min. Then, external defibrillation was attempted and observed for 120 min. The TRM group (n5) was filled with 300 mL of TRM645 for the PCPS circuit. The control group (n5) was filled with the same volume of saline. The delivery of oxygen (DO2) and oxygen consumption (VO2) decreased markedly by PCPS after CPA, compared to the preoperative values. DO2 was kept at a constant level during PCPS in both groups, but VO2 slowly decreased at 5, 10, and 15 min of PCPS in the control groups, demonstrating that systemic oxygen metabolism decreased with time. In contrast, the decreases in VO2 were small in the TRM group at 5, 10, and 15 min of PCPS, demonstrating that TRM645 continuously maintained systemic oxygen consumption even at a low flow rate. AST and LDH in the TRM group were lower than the control. There were significant differences at 120 min after the restoration of spontaneous circulation (p<0.05).</p
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