446 research outputs found
Internet of robotic things : converging sensing/actuating, hypoconnectivity, artificial intelligence and IoT Platforms
The Internet of Things (IoT) concept is evolving rapidly and influencing newdevelopments in various application domains, such as the Internet of MobileThings (IoMT), Autonomous Internet of Things (A-IoT), Autonomous Systemof Things (ASoT), Internet of Autonomous Things (IoAT), Internetof Things Clouds (IoT-C) and the Internet of Robotic Things (IoRT) etc.that are progressing/advancing by using IoT technology. The IoT influencerepresents new development and deployment challenges in different areassuch as seamless platform integration, context based cognitive network integration,new mobile sensor/actuator network paradigms, things identification(addressing, naming in IoT) and dynamic things discoverability and manyothers. The IoRT represents new convergence challenges and their need to be addressed, in one side the programmability and the communication ofmultiple heterogeneous mobile/autonomous/robotic things for cooperating,their coordination, configuration, exchange of information, security, safetyand protection. Developments in IoT heterogeneous parallel processing/communication and dynamic systems based on parallelism and concurrencyrequire new ideas for integrating the intelligent “devices”, collaborativerobots (COBOTS), into IoT applications. Dynamic maintainability, selfhealing,self-repair of resources, changing resource state, (re-) configurationand context based IoT systems for service implementation and integrationwith IoT network service composition are of paramount importance whennew “cognitive devices” are becoming active participants in IoT applications.This chapter aims to be an overview of the IoRT concept, technologies,architectures and applications and to provide a comprehensive coverage offuture challenges, developments and applications
Performance of ePix10K, a high dynamic range, gain auto-ranging pixel detector for FELs
ePix10K is a hybrid pixel detector developed at SLAC for demanding
free-electron laser (FEL) applications, providing an ultrahigh dynamic range
(245 eV to 88 MeV) through gain auto-ranging. It has three gain modes (high,
medium and low) and two auto-ranging modes (high-to-low and medium-to-low). The
first ePix10K cameras are built around modules consisting of a sensor flip-chip
bonded to 4 ASICs, resulting in 352x384 pixels of 100 m x 100 m each.
We present results from extensive testing of three ePix10K cameras with FEL
beams at LCLS, resulting in a measured noise floor of 245 eV rms, or 67 e
equivalent noise charge (ENC), and a range of 11000 photons at 8 keV. We
demonstrate the linearity of the response in various gain combinations: fixed
high, fixed medium, fixed low, auto-ranging high to low, and auto-ranging
medium-to-low, while maintaining a low noise (well within the counting
statistics), a very low cross-talk, perfect saturation response at fluxes up to
900 times the maximum range, and acquisition rates of up to 480 Hz. Finally, we
present examples of high dynamic range x-ray imaging spanning more than 4
orders of magnitude dynamic range (from a single photon to 11000
photons/pixel/pulse at 8 keV). Achieving this high performance with only one
auto-ranging switch leads to relatively simple calibration and reconstruction
procedures. The low noise levels allow usage with long integration times at
non-FEL sources. ePix10K cameras leverage the advantages of hybrid pixel
detectors with high production yield and good availability, minimize
development complexity through sharing the hardware, software and DAQ
development with all other versions of ePix cameras, while providing an upgrade
path to 5 kHz, 25 kHz and 100 kHz in three steps over the next few years,
matching the LCLS-II requirements.Comment: 9 pages, 5 figure
Field Scanner Design for MUSTANG of the Green Bank Telescope
MUSTANG is a bolometer camera for the Green Bank Telescope (GBT) working at a
frequency of 90 GHz. The detector has a field of view of 40 arcseconds. To
cancel out random emission change from atmosphere and other sources, requires a
fast scanning reflecting system with a few arcminute ranges. In this paper, the
aberrations of an off-axis system are reviewed. The condition for an optimized
system is provided. In an optimized system, as additional image transfer
mirrors are introduced, new aberrations of the off-axis system may be
reintroduced, resulting in a limited field of view. In this paper, different
scanning mirror arrangements for the GBT system are analyzed through the ray
tracing analysis. These include using the subreflector as the scanning mirror,
chopping a flat mirror and transferring image with an ellipse mirror, and
chopping a flat mirror and transferring image with a pair of face-to-face
paraboloid mirrors. The system analysis shows that chopping a flat mirror and
using a well aligned pair of paraboloids can generate the required field of
view for the MUSTUNG detector system, while other systems all suffer from
larger off-axis aberrations added by the system modification. The spot diagrams
of the well aligned pair of paraboloids produced is only about one Airy disk
size within a scanning angle of about 3 arcmin.Comment: 7 pages, 9 figure
An Instrument For Investigation of the Cosmic Microwave Background Radiation at Intermediate Angular Scales
We describe an off-axis microwave telescope for observations of the
anisotropy in the cosmic microwave background (CMB) radiation on angular scales
between 0.5 deg and 3 deg. The receiver utilizes cryogenic
high-electron-mobility transistor (HEMT) amplifiers and detects the total power
in multiple 3 GHz wide channels. Both frequency and polarization information
are recorded allowing discrimination between CMB radiation and potential
foreground sources and allowing checks for systematic effects. The instrumental
radiometric offset is small (~1 mK). Data are taken by rapidly sampling while
sweeping the beam many beamwidths across the sky. After detection, a
spatio-temporal filter is formed in software which optimizes the sensitivity in
a multipole band in the presence of atmospheric fluctuations. Observations were
made from Saskatoon, Saskatchewan (SK), Canada during the winter of 1993 with
six channels between 27.6 and 34.0 GHz, in 1994 with twelve channels between
27.6 and 44.1 GHz, and in 1995 with six channels between 38.2 and 44.1 GHz. The
performance of the instrument and assessment of the atmospheric noise at this
site are discussed.Comment: latex file is called inst.tex. 30 pages with 14 Postscript figures.
Uses aas2pp4.sty (included). Submitted to Ap
Design, Computational Modelling and Experimental Characterization of Bistable Hybrid Soft Actuators for a Controllable-Compliance Joint of an Exoskeleton Rehabilitation Robot
This paper presents the mechatronic design of a biorobotic joint with controllable compliance, for innovative applications of “assist-as-needed” robotic rehabilitation mediated by a wearable and soft exoskeleton. The soft actuation of robotic exoskeletons can provide some relevant advantages in terms of controllable compliance, adaptivity and intrinsic safety of the control performance of the robot during the interaction with the patient. Pneumatic Artificial Muscles (PAMs), which belong to the class of soft actuators, can be arranged in antagonistic configuration in order to exploit the variability of their mechanical compliance for the optimal adaptation of the robot performance during therapy. The coupling of an antagonistic configuration of PAMs with a regulation mechanism can achieve, under a customized control strategy, the optimal tuning of the mechanical compliance of the exoskeleton joint over full ranges of actuation pressure and joint rotation. This work presents a novel mechanism, for the optimal regulation of the compliance of the biorobotic joint, which is characterized by a soft and hybrid actuation exploiting the storage/release of the elastic energy by bistable Von Mises elastic trusses. The contribution from elastic Von Mises structure can improve both the mechanical response of the soft pneumatic bellows actuating the regulation mechanism and the intrinsic safety of the whole mechanism. A comprehensive set of design steps is presented here, including the optimization of the geometry of the pneumatic bellows, the fabrication process through 3D printing of the mechanism and some experimental tests devoted to the characterization of the hybrid soft actuation. The experimental tests replicated the main operating conditions of the regulation mechanism; the advantages arising from the bistable hybrid soft actuation were evaluated in terms of static and dynamic performance, e.g., pressure and force transition thresholds of the bistable mechanism, linearity and hysteresis of the actuator response
A cognitive robotic ecology approach to self-configuring and evolving AAL systems
Robotic ecologies are systems made out of several robotic devices, including mobile robots, wireless sensors and effectors embedded in everyday environments, where they cooperate to achieve complex tasks. This paper demonstrates how endowing robotic ecologies with information processing algorithms such as perception, learning, planning, and novelty detection can make these systems able to deliver modular, flexible, manageable and dependable Ambient Assisted Living (AAL) solutions. Specifically, we show how the integrated and self-organising cognitive solutions implemented within the EU project RUBICON (Robotic UBIquitous Cognitive Network) can reduce the need of costly pre-programming and maintenance of robotic ecologies. We illustrate how these solutions can be harnessed to (i) deliver a range of assistive services by coordinating the sensing & acting capabilities of heterogeneous devices, (ii) adapt and tune the overall behaviour of the ecology to the preferences and behaviour of its inhabitants, and also (iii) deal with novel events, due to the occurrence of new user's activities and changing user's habits
CMB Telescopes and Optical Systems
The cosmic microwave background radiation (CMB) is now firmly established as
a fundamental and essential probe of the geometry, constituents, and birth of
the Universe. The CMB is a potent observable because it can be measured with
precision and accuracy. Just as importantly, theoretical models of the Universe
can predict the characteristics of the CMB to high accuracy, and those
predictions can be directly compared to observations. There are multiple
aspects associated with making a precise measurement. In this review, we focus
on optical components for the instrumentation used to measure the CMB
polarization and temperature anisotropy. We begin with an overview of general
considerations for CMB observations and discuss common concepts used in the
community. We next consider a variety of alternatives available for a designer
of a CMB telescope. Our discussion is guided by the ground and balloon-based
instruments that have been implemented over the years. In the same vein, we
compare the arc-minute resolution Atacama Cosmology Telescope (ACT) and the
South Pole Telescope (SPT). CMB interferometers are presented briefly. We
conclude with a comparison of the four CMB satellites, Relikt, COBE, WMAP, and
Planck, to demonstrate a remarkable evolution in design, sensitivity,
resolution, and complexity over the past thirty years.Comment: To appear in: Planets, Stars and Stellar Systems (PSSS), Volume 1:
Telescopes and Instrumentatio
A segmented Hybrid Photon Detector with integrated auto-triggering front-end electronics for a PET scanner
We describe the design, fabrication and test results of a segmented Hybrid Photon Detector with integrated auto-triggering front-end electronics. Both the photodetector and its VLSI readout electronics are custom designed and have been tailored to the requirements of a recently proposed novel geometrical concept of a Positron Emission Tomograph. Emphasis is put on the PET specific features of the device. The detector has been fabricated in the photocathode facility at CERN
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