31 research outputs found
Task-Directed Exploration in Continuous POMDPs for Robotic Manipulation of Articulated Objects
Representing and reasoning about uncertainty is crucial for autonomous agents
acting in partially observable environments with noisy sensors. Partially
observable Markov decision processes (POMDPs) serve as a general framework for
representing problems in which uncertainty is an important factor. Online
sample-based POMDP methods have emerged as efficient approaches to solving
large POMDPs and have been shown to extend to continuous domains. However,
these solutions struggle to find long-horizon plans in problems with
significant uncertainty. Exploration heuristics can help guide planning, but
many real-world settings contain significant task-irrelevant uncertainty that
might distract from the task objective. In this paper, we propose STRUG, an
online POMDP solver capable of handling domains that require long-horizon
planning with significant task-relevant and task-irrelevant uncertainty. We
demonstrate our solution on several temporally extended versions of toy POMDP
problems as well as robotic manipulation of articulated objects using a neural
perception frontend to construct a distribution of possible models. Our results
show that STRUG outperforms the current sample-based online POMDP solvers on
several tasks
EARL: Eye-on-Hand Reinforcement Learner for Dynamic Grasping with Active Pose Estimation
In this paper, we explore the dynamic grasping of moving objects through
active pose tracking and reinforcement learning for hand-eye coordination
systems. Most existing vision-based robotic grasping methods implicitly assume
target objects are stationary or moving predictably. Performing grasping of
unpredictably moving objects presents a unique set of challenges. For example,
a pre-computed robust grasp can become unreachable or unstable as the target
object moves, and motion planning must also be adaptive. In this work, we
present a new approach, Eye-on-hAnd Reinforcement Learner (EARL), for enabling
coupled Eye-on-Hand (EoH) robotic manipulation systems to perform real-time
active pose tracking and dynamic grasping of novel objects without explicit
motion prediction. EARL readily addresses many thorny issues in automated
hand-eye coordination, including fast-tracking of 6D object pose from vision,
learning control policy for a robotic arm to track a moving object while
keeping the object in the camera's field of view, and performing dynamic
grasping. We demonstrate the effectiveness of our approach in extensive
experiments validated on multiple commercial robotic arms in both simulations
and complex real-world tasks.Comment: Presented on IROS 2023 Corresponding author Siddarth Jai
Style-transfer based Speech and Audio-visual Scene Understanding for Robot Action Sequence Acquisition from Videos
To realize human-robot collaboration, robots need to execute actions for new
tasks according to human instructions given finite prior knowledge. Human
experts can share their knowledge of how to perform a task with a robot through
multi-modal instructions in their demonstrations, showing a sequence of
short-horizon steps to achieve a long-horizon goal. This paper introduces a
method for robot action sequence generation from instruction videos using (1)
an audio-visual Transformer that converts audio-visual features and instruction
speech to a sequence of robot actions called dynamic movement primitives (DMPs)
and (2) style-transfer-based training that employs multi-task learning with
video captioning and weakly-supervised learning with a semantic classifier to
exploit unpaired video-action data. We built a system that accomplishes various
cooking actions, where an arm robot executes a DMP sequence acquired from a
cooking video using the audio-visual Transformer. Experiments with
Epic-Kitchen-100, YouCookII, QuerYD, and in-house instruction video datasets
show that the proposed method improves the quality of DMP sequences by 2.3
times the METEOR score obtained with a baseline video-to-action Transformer.
The model achieved 32% of the task success rate with the task knowledge of the
object.Comment: Accepted to Interspeech202
EGFR Dynamics Change during Activation in Native Membranes as Revealed by NMR
The epidermal growth factor receptor (EGFR) represents one of the most common target proteins in anti-cancer therapy. To directly examine the structural and dynamical properties of EGFR activation by the epidermal growth factor (EGF) in native membranes, we have developed a solid-state nuclear magnetic resonance (ssNMR)-based approach supported by dynamic nuclear polarization (DNP). In contrast to previous crystallographic results, our experiments show that the ligand-free state of the extracellular domain (ECD) is highly dynamic, while the intracellular kinase domain (KD) is rigid. Ligand binding restricts the overall and local motion of EGFR domains, including the ECD and the C-terminal region. We propose that the reduction in conformational entropy of the ECD by ligand binding favors the cooperative binding required for receptor dimerization, causing allosteric activation of the intracellular tyrosine kinase
EGFR Dynamics Change during Activation in Native Membranes as Revealed by NMR
The epidermal growth factor receptor (EGFR) represents one of the most common target proteins in anti-cancer therapy. To directly examine the structural and dynamical properties of EGFR activation by the epidermal growth factor (EGF) in native membranes, we have developed a solid-state nuclear magnetic resonance (ssNMR)-based approach supported by dynamic nuclear polarization (DNP). In contrast to previous crystallographic results, our experiments show that the ligand-free state of the extracellular domain (ECD) is highly dynamic, while the intracellular kinase domain (KD) is rigid. Ligand binding restricts the overall and local motion of EGFR domains, including the ECD and the C-terminal region. We propose that the reduction in conformational entropy of the ECD by ligand binding favors the cooperative binding required for receptor dimerization, causing allosteric activation of the intracellular tyrosine kinase
Nations within a nation: variations in epidemiological transition across the states of India, 1990–2016 in the Global Burden of Disease Study
18% of the world's population lives in India, and many states of India have populations similar to those of large countries. Action to effectively improve population health in India requires availability of reliable and comprehensive state-level estimates of disease burden and risk factors over time. Such comprehensive estimates have not been available so far for all major diseases and risk factors. Thus, we aimed to estimate the disease burden and risk factors in every state of India as part of the Global Burden of Disease (GBD) Study 2016