14 research outputs found
Coordinated Multi-Robot Shared Autonomy Based on Scheduling and Demonstrations
Shared autonomy methods, where a human operator and a robot arm work
together, have enabled robots to complete a range of complex and highly
variable tasks. Existing work primarily focuses on one human sharing autonomy
with a single robot. By contrast, in this paper we present an approach for
multi-robot shared autonomy that enables one operator to provide real-time
corrections across two coordinated robots completing the same task in parallel.
Sharing autonomy with multiple robots presents fundamental challenges. The
human can only correct one robot at a time, and without coordination, the human
may be left idle for long periods of time. Accordingly, we develop an approach
that aligns the robot's learned motions to best utilize the human's expertise.
Our key idea is to leverage Learning from Demonstration (LfD) and time warping
to schedule the motions of the robots based on when they may require
assistance. Our method uses variability in operator demonstrations to identify
the types of corrections an operator might apply during shared autonomy,
leverages flexibility in how quickly the task was performed in demonstrations
to aid in scheduling, and iteratively estimates the likelihood of when
corrections may be needed to ensure that only one robot is completing an action
requiring assistance. Through a preliminary simulated study, we show that our
method can decrease the overall time spent sanding by iteratively estimating
the times when each robot could need assistance and generating an optimized
schedule that allows the operator to provide corrections to each robot during
these times.Comment: This work has been submitted to the IEEE for possible publication.
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Alternative Splicing Modulates Kv Channel Clustering through a Molecular ‘Ball and Chain’ Mechanism
Coherent ultrafast lattice-directed reaction dynamics of triiodide anion photodissociation
Solid-state reactions are influenced by the spatial arrangement of the reactants and the electrostatic environment of the lattice, which may enable lattice-directed chemical dynamics. Unlike the caging imposed by an inert matrix, an active lattice participates in the reaction, however, little evidence of such lattice participation has been gathered on ultrafast timescales due to the irreversibility of solid-state chemical systems. Here, by lowering the temperature to 80 K, we have been able to study the dissociative photochemistry of the triiodide anion (I<sub>3</sub>−) in single-crystal tetra-n-butylammonium triiodide using broadband transient absorption spectroscopy. We identified the coherently formed tetraiodide radical anion (I<sub>4</sub>•−) as a reaction intermediate. Its delayed appearance after that of the primary photoproduct, diiodide radical I<sub>2</sub>•−, indicates that I<sub>4</sub>•− was formed via a secondary reaction between a dissociated iodine radical (I<sup>•</sup>) and an adjacent I<sub>3</sub>−. This chemistry occurs as a result of the intermolecular interaction determined by the crystalline arrangement and is in stark contrast with previous solution studies