12 research outputs found

    ATLAS liquid argon calorimeter front end electronics

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    The ATLAS detector has been designed for operation at CERN's Large Hadron Collider. ATLAS includes a complex system of liquid argon calorimeters. This paper describes the architecture and implementation of the system of custom front end electronics developed for the readout of the ATLAS liquid argon calorimeters

    UNMANNED GROUND VEHICLE (UGV) DOCKING, CONNECTION, AND CABLING FOR ELECTRICAL POWER TRANSMISSION IN AUTONOMOUS MOBILE MICROGRIDS

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    Autonomous Mobile Microgrids provide electrical power to loads in environments where humans either can not, or would prefer not to, perform the task of positioning and connecting the power grid equipment. The contributions of this work compose an architecture for electrical power transmission by Unmanned Ground Vehicles (UGV). Purpose-specific UGV docking and cable deployment software algorithms, and hardware for electrical connection and cable management, has been deployed on Clearpath Husky robots. Software development leverages Robot Operating System (ROS) tools for navigation and rendezvous of the autonomous UGV robots, with task-specific visual feedback controllers for docking validated in Monte-Carlo outdoor trials with a 73% docking rate, and application to wireless power transmission demonstrated in an outdoor environment. An “Adjustable Cable Management Mechanism” (ACMM) was designed to meet low cost, compact-platform constraints for powered deployment and retraction by a UGV of electrical cable subject to disturbance, with feed rates up to 1 m/s. A probe-and-funnel AC/DC electrical connector system was de- veloped for deployment on UGVs, which does not substantially increase the cost or complexity of the UGV, while providing a repeatable and secure method of coupling electrical contacts subject to a docking miss-alignment of up to +/-2 cm laterally and +/-15 degrees axially. Cabled power transmission is accomplished by a feed-forward/feedback control method, which utilizes visual estimation of the cable state to deploy electrical cable without tension, in the obstacle-free track of the UGV as it transverses to connect power grid nodes. Cabling control response to step-input UGV chassis velocities in the forward, reverse, and zero-point-turn maneuvers are presented, as well as outdoor cable deployment. This power transmission capability is relevant to diverse domains including military Forward-Operating-Bases, disaster response, robotic persistent operation, underwater mining, or planetary exploration

    STS ancillary equipment study. User reference book

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    A record of what is currently known about STS ancillary equipment is presented in this user-oriented design so that a potential user may evaluate whether he could use the described ancillary equipment or if he would need to design and fabricate a payload-unique item. References that the user can use to obtain additional details and requirements to aid in his evaluation and decision are included

    The robotic multiobject focal plane system of the Dark Energy Spectroscopic Instrument (DESI)

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    Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, los autores pertenecientes a la UAM y el nombre del grupo de colaboración, si lo hubiereA system of 5020 robotic fiber positioners was installed in 2019 on the Mayall Telescope, at Kitt Peak National Observatory. The robots automatically retarget their optical fibers every 10-20 minutes, each to a precision of several microns, with a reconfiguration time of fewer than 2 minutes. Over the next 5 yr, they will enable the newly constructed Dark Energy Spectroscopic Instrument (DESI) to measure the spectra of 35 million galaxies and quasars. DESI will produce the largest 3D map of the universe to date and measure the expansion history of the cosmos. In addition to the 5020 robotic positioners and optical fibers, DESI’s Focal Plane System includes six guide cameras, four wave front cameras, 123 fiducial point sources, and a metrology camera mounted at the primary mirror. The system also includes associated structural, thermal, and electrical systems. In all, it contains over 675,000 individual parts. We discuss the design, construction, quality control, and integration of all these components. We include a summary of the key requirements, the review and acceptance process, on-sky validations of requirements, and lessons learned for future multiobject, fiber-fed spectrograph

    The Robotic Multiobject Focal Plane System of the Dark Energy Spectroscopic Instrument (DESI)

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    A system of 5020 robotic fiber positioners was installed in 2019 on the Mayall Telescope, at Kitt Peak National Observatory. The robots automatically retarget their optical fibers every 10-20 minutes, each to a precision of several microns, with a reconfiguration time of fewer than 2 minutes. Over the next 5 yr, they will enable the newly constructed Dark Energy Spectroscopic Instrument (DESI) to measure the spectra of 35 million galaxies and quasars. DESI will produce the largest 3D map of the universe to date and measure the expansion history of the cosmos. In addition to the 5020 robotic positioners and optical fibers, DESI’s Focal Plane System includes six guide cameras, four wave front cameras, 123 fiducial point sources, and a metrology camera mounted at the primary mirror. The system also includes associated structural, thermal, and electrical systems. In all, it contains over 675,000 individual parts. We discuss the design, construction, quality control, and integration of all these components. We include a summary of the key requirements, the review and acceptance process, on-sky validations of requirements, and lessons learned for future multiobject, fiber-fed spectrographs

    Orbital service module systems analysis study documentation. Volume 2: Technical report

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    Near term, cost effective concepts were defined to augment the power and duration capability offered to shuttle payload users. Feasible concept options that could evolve to provide free-flying power and other services to users in the 1984 time frame were also examined

    ALICE upgrades during the LHC Long Shutdown 2

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    A Large Ion Collider Experiment (ALICE) has been conceived and constructed as a heavy-ion experiment at the LHC. During LHC Runs 1 and 2, it has produced a wide range of physics results using all collision systems available at the LHC. In order to best exploit new physics opportunities opening up with the upgraded LHC and new detector technologies, the experiment has undergone a major upgrade during the LHC Long Shutdown 2 (2019-2022). This comprises the move to continuous readout, the complete overhaul of core detectors, as well as a new online event processing farm with a redesigned online-offline software framework. These improvements will allow to record Pb-Pb collisions at rates up to 50 kHz, while ensuring sensitivity for signals without a triggerable signature.Comment: 159 pages, 110 captioned figures, 10 tables, authors from page 153, published version, figures at http://alice-publications.web.cern.ch/node/896

    Design and Experimental Evaluation of a Hybrid Wheeled-Leg Exploration Rover in the Context of Multi-Robot Systems

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    With this dissertation, the electromechanic design, implementation, locomotion control, and experimental evaluation of a novel type of hybrid wheeled-leg exploration rover are presented. The actively articulated suspension system of the rover is the basis for advanced locomotive capabilities of a mobile exploration robot. The developed locomotion control system abstracts the complex kinematics of the suspension system and provides platform control inputs usable by autonomous behaviors or human remote control. Design and control of the suspension system as well as experimentation with the resulting rover are in the focus of this thesis. The rover is part of a heterogeneous modular multi-robot exploration system with an aspired sample return mission to the lunar south pole or currently hard-to-access regions on Mars. The multi-robot system pursues a modular and reconfigurable design methodology. It combines heterogeneous robots with different locomotion capabilities for enhanced overall performance. Consequently, the design of the multi-robot system is presented as the frame of the rover developments. The requirements for the rover design originating from the deployment in a modular multi-robot system are accentuated and summarized in this thesis

    Experiments in thin film deposition : plasma-based fabrication of carbon nanotubes and magnesium diboride thin films.

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    Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2004.A simple, low-cost plasma reactor was developed for the purpose of carrying out thin film deposition experiments. The reactor is based largely on the Atmospheric Pressure Nonequilibrium Plasma (APNEP) design with a simple modification. It was used in an attempt to fabricate magnesium diboride thin films via a novel, but unsuccessful CVD process where plasma etching provides a precursor boron flux. Carbon nanotubes were successfully synthesised with the apparatus using a plasma-based variation of the floating catalyst or vapour phase growth method. The affect of various parameters and chemicals on the quality of nanotube production was assessed

    Construction, Commissioning and Performance Measurements of the Inner Tracking System Upgrade (ITS2) of ALICE at the LHC

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    A Large Ion Collider Experiment (ALICE), situated on the Large Hadron Collider (LHC), is optimised to study relativistic heavy-ion collisions in order to quantitatively characterise the Quark Gluon Plasma. The inner-most detector system, the Inner Tracking System (ITS), is responsible for primary and secondary vertex reconstruction in the vicinity of the interaction point, as well as stand-alone tracking of particles unable to reach the rest of the ALICE sub-detectors, due to momentum cut-off and acceptance limitations. The ITS was upgraded over the LHC Long Shutdown 2 (late 2018 - early 2022) with the aims of improving the impact parameter resolution, tracking efficiency, transverse momentum resolution, and readout rate. This was achieved by replacing the ITS used in LHC Runs 1 and 2 by seven concentric layers of silicon pixel detector, utilising a Monolithic Active Pixel Sensors (MAPS) design known as ALPIDE, together with the reduction of the radius of the inner-most layer by 16 mm, the reduction of the material budget and the decrease of the pixel pitch. Over the last few years, the upgraded ITS, ITS2, was successfully constructed at several international sites before being assembled into the concentric barrel structure of the final tracker at CERN. The detector was then integrated into the final services including the readout and power systems before undergoing a comprehensive commissioning campaign. This thesis concerns the construction, characterisation, and commissioning of the outer-most four layers of the ITS2, known as the Outer Barrel. Namely, the construction and characterisation of the detector modules and staves, the verification of the final system, and the acquisition of the first real particle data set and subsequent performance measurements
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