448 research outputs found
Sensorless Physical Human-robot Interaction Using Deep-Learning
Physical human-robot interaction has been an area of interest for decades.
Collaborative tasks, such as joint compliance, demand high-quality joint torque
sensing. While external torque sensors are reliable, they come with the
drawbacks of being expensive and vulnerable to impacts. To address these
issues, studies have been conducted to estimate external torques using only
internal signals, such as joint states and current measurements. However,
insufficient attention has been given to friction hysteresis approximation,
which is crucial for tasks involving extensive dynamic to static state
transitions. In this paper, we propose a deep-learning-based method that
leverages a novel long-term memory scheme to achieve dynamics identification,
accurately approximating the static hysteresis. We also introduce modifications
to the well-known Residual Learning architecture, retaining high accuracy while
reducing inference time. The robustness of the proposed method is illustrated
through a joint compliance and task compliance experiment.Comment: 7 pages, ICRA 2024 Submissio
A Network Coding Approach to Loss Tomography
Network tomography aims at inferring internal network characteristics based
on measurements at the edge of the network. In loss tomography, in particular,
the characteristic of interest is the loss rate of individual links and
multicast and/or unicast end-to-end probes are typically used. Independently,
recent advances in network coding have shown that there are advantages from
allowing intermediate nodes to process and combine, in addition to just
forward, packets. In this paper, we study the problem of loss tomography in
networks with network coding capabilities. We design a framework for estimating
link loss rates, which leverages network coding capabilities, and we show that
it improves several aspects of tomography including the identifiability of
links, the trade-off between estimation accuracy and bandwidth efficiency, and
the complexity of probe path selection. We discuss the cases of inferring link
loss rates in a tree topology and in a general topology. In the latter case,
the benefits of our approach are even more pronounced compared to standard
techniques, but we also face novel challenges, such as dealing with cycles and
multiple paths between sources and receivers. Overall, this work makes the
connection between active network tomography and network coding
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