155 research outputs found
Autonomous Sweet Pepper Harvesting for Protected Cropping Systems
In this letter, we present a new robotic harvester (Harvey) that can
autonomously harvest sweet pepper in protected cropping environments. Our
approach combines effective vision algorithms with a novel end-effector design
to enable successful harvesting of sweet peppers. Initial field trials in
protected cropping environments, with two cultivar, demonstrate the efficacy of
this approach achieving a 46% success rate for unmodified crop, and 58% for
modified crop. Furthermore, for the more favourable cultivar we were also able
to detach 90% of sweet peppers, indicating that improvements in the grasping
success rate would result in greatly improved harvesting performance
Reactive Base Control for On-The-Move Mobile Manipulation in Dynamic Environments
We present a reactive base control method that enables high performance
mobile manipulation on-the-move in environments with static and dynamic
obstacles. Performing manipulation tasks while the mobile base remains in
motion can significantly decrease the time required to perform multi-step
tasks, as well as improve the gracefulness of the robot's motion. Existing
approaches to manipulation on-the-move either ignore the obstacle avoidance
problem or rely on the execution of planned trajectories, which is not suitable
in environments with dynamic objects and obstacles. The presented controller
addresses both of these deficiencies and demonstrates robust performance of
pick-and-place tasks in dynamic environments. The performance is evaluated on
several simulated and real-world tasks. On a real-world task with static
obstacles, we outperform an existing method by 48\% in terms of total task
time. Further, we present real-world examples of our robot performing
manipulation tasks on-the-move while avoiding a second autonomous robot in the
workspace. See https://benburgesslimerick.github.io/MotM-BaseControl for
supplementary materials
Science with an ngVLA - The Molecular High-z Universe on Large Scales: Low-surface-brightness CO and the strength of the ngVLA Core
The Next-Generation Very Large Array (ngVLA) will revolutionize our
understanding of the Early Universe by tracing the coldest phase of molecular
gas -the raw ingredient for star formation- in the most distant galaxies and
galaxy-clusters. The km-scale core of the ngVLA will be densely packed with
antennas, making it a prime instrument for imaging low-surface-brightness
emission from large-scale molecular gas in the high-z circum- and
inter-galactic medium (CGM/IGM). Recent studies indicate that large amounts of
cold molecular gas are hiding in the 10s-100 kpc environments of distant
galaxies, but that technical limitations on existing telescope arrays have
prevented us from efficiently detecting these large molecular reservoirs. This
may have led to a severely biased view of the molecular Universe. We present
the science case for low-surface-brightness CO observations of the Early
Universe, and how the core of the ngVLA will reveal the cold molecular Universe
to limits and at scales not currently detectable by radio telescopes. As such,
the ngVLA core will be a powerful instrument for studying the cold baryon cycle
that drives the early evolution of galaxies and clusters.Comment: To be published in the ASP Monograph Series, "Science with a
Next-Generation VLA", ed. E. J. Murphy (ASP, San Francisco, CA) - 8 pages, 4
figure
CO survey of high-z radio galaxies, revisited with ALMA: Jet-cloud Alignments and Synchrotron Brightening by Molecular Gas in the Circumgalactic Environment
Powerful radio sources associated with super-massive black holes are among
the most luminous objects in the Universe, and are frequently recognized both
as cosmological probes and active constituents in the evolution of galaxies. We
present alignments between radio jets and cold molecular gas in the environment
of distant radio galaxies, and show that the brightness of the radio
synchrotron source can be enhanced by its interplay with the molecular gas. Our
work is based on CO J>1 observations with the Atacama Large
Millimeter/submillimeter Array (ALMA) of three radio galaxies with redshifts in
the range 1.4 < z < 2.1, namely MRC 0114-211 (z = 1.41), MRC 0156-252 (z =
2.02), and MRC 2048-272 (z = 2.05). These ALMA observations support previous
work that found molecular gas out to 50 kpc in the circumgalactic environment,
based on a CO(1-0) survey performed with the Australia Telescope Compact Array
(ATCA). The CO emission is found along the radio axes but beyond the main radio
lobes. When compared to a large sample of high-z radio galaxies from the
literature, we find that the presence of this cold molecular medium correlates
with an increased flux-density ratio of the main vs. counter lobe. This suggest
that the radio lobe brightens when encountering cold molecular gas in the
environment. While part of the molecular gas is likely related to the
interstellar medium (ISM) from either the host or a companion galaxy, a
significant fraction of the molecular gas in these systems shows very low
excitation, with r and r values 0.2. This
could be part of the circumgalactic medium (CGM).Comment: Accepted for publication in ApJ (19 pages, 6 figures
An OSIRIS study of the gas kinematics in a sample of UV-selected galaxies: Evidence of "Hot and Bothered" starbursts in the local Universe
We present data from Integral Field Spectroscopy for 3 supercompact
UV-Luminous Galaxies (ScUVLGs). As nearby (z~0.2), compact (R_50~1-2 kpc),
bright Paschen-alpha sources, with unusually high star formation rates
(SFR=3-100 M_sun/yr), ScUVLGs are an ideal population for studying detailed
kinematics and dynamics in actively star-forming galaxies. In addition, ScUVLGs
appear to be excellent analogs to high redshift Lyman Break Galaxies (LBGs) and
our results may offer additional insight into the dynamics of LBGs. Previous
work by our team has shown that the morphologies of these galaxies exhibit
tidal features and companions, and in this study we find that the dynamics of
ScUVLGs are dominated by disturbed kinematics of the emission line gas--
suggestive that these galaxies have undergone recent feedback, interactions or
mergers. While 2 of the 3 galaxies do display rotation, v/sigma < 1 --
suggesting dispersion dominated kinematics rather than smooth rotation. We also
simulate how these observations would appear at z~2. Lower resolution and loss
of low surface brightness features causes some apparent discrepancies between
the low-z (observed) and high-z (simulated) interpretations and quantitatively
gives different values for v/sigma, yet simulations of these low-z analogs
manage to detect the brightest regions well and resemble actual high-z
observations of LBGs.Comment: 4 pages, 4 figures (bitmapped), accepted for publication in ApJ
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