105 research outputs found
Handling robot constraints within a Set-Based Multi-Task Priority Inverse Kinematics Framework
Set-Based Multi-Task Priority is a recent framework to handle inverse
kinematics for redundant structures. Both equality tasks, i.e., control
objectives to be driven to a desired value, and set-bases tasks, i.e., control
objectives to be satisfied with a set/range of values can be addressed in a
rigorous manner within a priority framework. In addition, optimization tasks,
driven by the gradient of a proper function, may be considered as well, usually
as lower priority tasks. In this paper the proper design of the tasks, their
priority and the use of a Set-Based Multi-Task Priority framework is proposed
in order to handle several constraints simultaneously in real-time. It is shown
that safety related tasks such as, e.g., joint limits or kinematic singularity,
may be properly handled by consider them both at an higher priority as
set-based task and at a lower within a proper optimization functional.
Experimental results on a 7DOF Jaco$^2
Safety-related Tasks within the Set-Based Task-Priority Inverse Kinematics Framework
In this paper we present a framework that allows the motion control of a
robotic arm automatically handling different kinds of safety-related tasks. The
developed controller is based on a Task-Priority Inverse Kinematics algorithm
that allows the manipulator's motion while respecting constraints defined
either in the joint or in the operational space in the form of equality-based
or set-based tasks. This gives the possibility to define, among the others,
tasks as joint-limits, obstacle avoidance or limiting the workspace in the
operational space. Additionally, an algorithm for the real-time computation of
the minimum distance between the manipulator and other objects in the
environment using depth measurements has been implemented, effectively allowing
obstacle avoidance tasks. Experiments with a Jaco manipulator, operating in
an environment where an RGB-D sensor is used for the obstacles detection, show
the effectiveness of the developed system
An Assistive Shared Control Architecture for a Robotic Arm Using EEG-Based BCI with Motor Imagery
Effects of Dynamic Model Errors in Task-Priority Operational Space Control
Control algorithms of many Degrees Of Freedom (DOFs) systems based on Inverse
Kinematics or Inverse Dynamics approaches are two well-known topics of research
in robotics. The large number of DOFs allows the design of many concurrent tasks
arranged in priorities, that can be solved either at kinematic or dynamic level. This
paper investigates the effects of modeling errors in operational space control algorithms
with respect to uncertainties affecting knowledge of the dynamic parameters. The effects
on the null-space projections and the sources of steady-state errors are investigated.
Numerical simulations with on-purpose injected errors are used to validate the thoughts
A Control Architecture for Safe Trajectory Generation in Human–Robot Collaborative Settings
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New evidence on blind snake presence in Sicily stress the need for targeted monitoring
The Brahminy blind snake, Indotyphlops braminus, is the most widely introduced reptile globally. Its spread has been facilitated by the international plant trade, owing to its ability to inhabit plant pots. In Europe, I. braminus is found in Spain (mainland Spain and Canary Islands: Tenerife, Lanzarote, Gran Canaria, Fuerteventura and La Gomera), Portugal (Madeira Island), Malta and Italy (Ischia and Sicily Islands). This study presents data on the long-term persistence of I. braminus at the first occurrence site in Sicily (Paceco, western Sicily) and new records of the species in this region. Observations in Paceco from 2017 to 2023 suggest the possible survival of a population. Furthermore, individuals attributable to this species were observed in two additional sites, both in urban contexts: the island of Pantelleria (Sicily channel) where two specimens were found in the same site in 2023 and 2024 and Valderice (western Sicily). Our findings indicates that I. braminus may be significantly more widespread in Sicily than previously known. Therefore, further surveys in this area are necessary, and monitoring these sites could be crucial in assessing the survival of this species in Mediterranean climates. 
Energy response of GR-200A thermoluminescence dosemeters to CO-60 and to monoenergetic synchrotron radiation in the energy range 28-40 KEV
7noThe response of LiF:Mg,Cu,P thermoluminescence dosemeters (type GR-200A) to monoenergetic radiation of energy 28, 35, 38 and 40 keV was evaluated with respect to irradiation with a calibrated 60Co gamma-ray source. High-precision measurements of the relative air kerma response performed at the SYRMEP beamline of the ELETTRA synchrotron radiation facility (Trieste, Italy) showed a significant deviation of the average response to low-energy X-rays from that to 60Co, with an over-response from 6 % (at 28 keV) to 22 % (at 40 keV). These data are not consistent with literature data for these dosemeters, where model predictions gave deviation from unity of the relative air kerma response of about 10 %. The authors conclude for the need of additional determinations of the low-energy relative response of GR-200A dosemeters, covering a wider range of monoenergetic energies sampled at a fine energy step, as planned in future experiments by their group at the ELETTRA facility.Published online first 02 March 2015partially_openembargoed_20160302F. Emiro; F. Di Lillo; G. Mettivier; C. Fedon; R. Longo; G. Tromba; P. RussoF., Emiro; F., Di Lillo; G., Mettivier; Fedon, Christian; Longo, Renata; G., Tromba; P., Russ
Measurement properties and confirmatory factor analysis of the Jefferson Scale of Empathy in Italian medical students
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