152,871 research outputs found
Design and construction of a configurable full-field range imaging system for mobile robotic applications
Mobile robotic devices rely critically on extrospection sensors to determine the range to objects in the robotâs operating environment. This provides the robot with the ability both to navigate safely around obstacles and to map its environment and hence facilitate path planning and navigation. There is a requirement for a full-field range imaging system that can determine the range to any obstacle in a camera lensâ field of view accurately and in real-time. This paper details the development of a portable full-field ranging system whose bench-top version has demonstrated sub-millimetre precision. However, this precision required non-real-time acquisition rates and expensive hardware. By iterative replacement of components, a portable, modular and inexpensive version of this full-field ranger has been constructed, capable of real-time operation with some (user-defined) trade-off with precision
A radiation-hard dual-channel 12-bit 40 MS/s ADC prototype for the ATLAS liquid argon calorimeter readout electronics upgrade at the CERN LHC
The readout electronics upgrade for the ATLAS Liquid Argon Calorimeters at
the CERN Large Hadron Collider requires a radiation-hard ADC. The design of a
radiation-hard dual-channel 12-bit 40 MS/s pipeline ADC for this use is
presented. The design consists of two pipeline A/D channels each with four
Multiplying Digital-to-Analog Converters followed by 8-bit
Successive-Approximation-Register analog-to-digital converters. The custom
design, fabricated in a commercial 130 nm CMOS process, shows a performance of
67.9 dB SNDR at 10 MHz for a single channel at 40 MS/s, with a latency of 87.5
ns (to first bit read out), while its total power consumption is 50 mW/channel.
The chip uses two power supply voltages: 1.2 and 2.5 V. The sensitivity to
single event effects during irradiation is measured and determined to meet the
system requirements
Observer based feedback control of 3rd order LCC resonant converters
The paper considers specific issues related to the design and realisation of observer-based feedback of isolated output voltage for resonant power converters. To provide a focus to the study, a 3rd order LCC converter is employed as a candidate topology. It is shown that whilst resonant converters nominally operate at high switching frequencies to facilitate the use of small reactive components, by appropriate pre-conditioning of non-isolated resonant-tank voltages and currents, the resulting observer can be implemented at relatively low sampling frequencies, and hence, take advantage of low-cost digital hardware.
Experimental results are used to demonstrate the accuracy of observer estimates under both transient and steady-state operating conditions, and to show operation of the observer as part of a closed-loop feedback system where the LCC resonant converter is used as a regulated power supply
A Radiation-Hard Dual Channel 4-bit Pipeline for a 12-bit 40 MS/s ADC Prototype with extended Dynamic Range for the ATLAS Liquid Argon Calorimeter Readout Electronics Upgrade at the CERN LHC
The design of a radiation-hard dual channel 12-bit 40 MS/s pipeline ADC with
extended dynamic range is presented, for use in the readout electronics upgrade
for the ATLAS Liquid Argon Calorimeters at the CERN Large Hadron Collider. The
design consists of two pipeline A/D channels with four Multiplying
Digital-to-Analog Converters with nominal 12-bit resolution each. The design,
fabricated in the IBM 130 nm CMOS process, shows a performance of 68 dB SNDR at
18 MHz for a single channel at 40 MS/s while consuming 55 mW/channel from a 2.5
V supply, and exhibits no performance degradation after irradiation. Various
gain selection algorithms to achieve the extended dynamic range are implemented
and tested.Comment: 22 pages, 22 figures, accepted by JINS
Concrete materials : series 1
This book provides the various usages of materials for producing good concrete. It will appeal to several major audiences. It is a compilation of works which using different types of material in concrete. There have been researches, literatures, methodologies and results that reveal the materials act in concrete. Some guidelines and suggestion also have been included for improving the utilization of the materials. It is expected that the skills of concrete produced will be enhanced by more exploration in experimental experiences
The STAR MAPS-based PiXeL detector
The PiXeL detector (PXL) for the Heavy Flavor Tracker (HFT) of the STAR
experiment at RHIC is the first application of the state-of-the-art thin
Monolithic Active Pixel Sensors (MAPS) technology in a collider environment.
Custom built pixel sensors, their readout electronics and the detector
mechanical structure are described in detail. Selected detector design aspects
and production steps are presented. The detector operations during the three
years of data taking (2014-2016) and the overall performance exceeding the
design specifications are discussed in the conclusive sections of this paper
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