1,720,963 research outputs found
Integrated Sensors & Read-Out: simulations, design and tests for highly advanced applications, from Robotics to High Energy Physics
No full textThis thesis presents design, simulations and tests of Silicon CMOS and Bi-CMOS sensors and read-out circuits for robotic and high energy physics applications. The project is divided in two main sub-parts: • Design, analysis, simulations, layout and tests of integrated sensors and electronic read-out circuits. Integrated temperature sensor and reference were designed for biomedical applications, while two read-out circuits were conceived to interface pressure sensors in robotic applications, more specifically hand exoskeletons and robotic tactile skin. • Physics performance studies of the Pixel detectors of the ATLAS experiment at CERN, as an example of advanced silicon device for ionizing particle detection. The fist Chapters of this thesis intend to show that even if most robotic applications prefer to rely on commercially available ICs to read-out tactile information, a custom solution can be even more effective as it offers some crucial advantages. For instance, human response to touch has a complex dynamics which is very difficult to be faithfully replicated at robotic-level with a general-purpose block, such as a microcontroller. On the contrary, custom solutions offer a much higher flexibility to reproduce human physiology at robotic level, without compromising the system modularity. The presented read-out circuits feature the crucial advantage of tunable output sensitivity, low-power consumption and compact size. Furthermore,they are designed with logic blocks only, to be modularly replicated and possibly implemented in different technologies with low efforts. The analog-to-digital conversion was achieved through a voltage-to-frequency conversion, which is an effective technique to partially attenuate the dramatic consequences of scaling in purely analog design. The read-out circuit for tactile skin has the major advantage of robustness with respect to process, voltage and temperature variations, which makes the solution even more attractive for the read-out of robotic systems. The interface for hand exoskeleton presents the important feature of providing both contact detection and pressure evaluation. The thesis details all steps carried out by the candidate, from the transistor-level design, through the simulations and layout to the electrical measurements, which allow to test the performance of the read-out circuit couple with the sensor. The temperature sensor and reference were designed in Bi-CMOS technology and exploited a bandgap architecture to take advantage of the linear dependence of bipolar transistor base-emitter voltage with absolute temperature. These ICs are still under development, hence only design and simulations are provided. Nevertheless, knowledge gained from the analog design (e.g., temperature dependence of integrated capacitors) was later used for the performance analysis of the pixel sensor of the IBL sub-detector. Experience achieved from design of integrated sensors and electronic interfaces offers peculiar expertise to analyze the performance of pixel sensors for particle Physics applications in terms of charge collection properties. The pixel integrated sensor and read-out circuit was studied in detail thanks to the expertise gained by designing the previously presented ICs. Specifically, it was demonstrated that effects in the read-out system (e.g., quantization resolution, electronic noise, radiation damage of the sensitive substrate) play an important role in defining the sensor performance, hence dramatically affect the tracking performance of the overall LHC. The pixel performance was studied in terms of charge calibration, spatial resolution optimization and two track separation. This analysis was performed using both custom simulations of charge collection phenomena (occurring at the sensor and read-out level) and official ATLAS Monte Carlo simulation software. The results were successfully compared to ATLAS collision data and result of dedicated Beam Test
A Flexible Low-Power 130 nm CMOS Read-Out Circuit With Tunable Sensitivity for Commercial Robotic Resistive Pressure Sensors
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A flexible resistive Read-Out Circuit suitable to multi-purpose ZnO nanostructured transducers for robotic applications
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Commercial tactile sensors for hand exoskeletons: practical considerations for ultra-low cost and very-low complexity read-out
No full textIn the last two decades, wearable robots have emerged as human-oriented devices to complement, substitute
or enhance human capabilities and, more specifically, empower or replace a human limb [1], [2]. Among the most
complex and interesting limbs to assist, the hand represents perhaps the biggest challenge, because of its primary
role in environment exploration, stimuli sensing and object manipulation [3]. Hence, the development of wearable and rehabilitative exoskeletons is increasingly attracting attention to help finger movements in free motion and assist the user with
grasping.
This paper shows that a simple underpowered digital oscillator electronic interface takes advantage of the capacitive variations in commercial piezoresistive transducers to sense applied pressure. Furthermore, thanks to the analysis of the static performance, practical considerations are drawn about the use of commercial sensors and a read out circuit (ROC) to be exploited in a control system for hand exoskeletons (Fig. 1)
New updates on the ATLAS ROD board implementation for Pixel Layer 1 and Layer 2
No full textThis work intends to briefly overview the new technological updates on the LHC ATLAS acquisition system of the Pixel Detector. The herein presented Read-Out Driver (ROD) is a VME board devoted to data processing, configuration and control. It is designed to provide data formatting, front-end specific error handling, and calibration. This board was initially designed to interface the data sensed by the Insertable B-Layer (IBL) with the ATLAS Trigger and Data AcQuisition (TDAQ) system. IBL is the innermost sensing layer of the ATLAS Pixel Detector, added during the 2013/2014 LHC long shutdown, to withstand higher luminosity and feature higher throughput performance. To readout the new layer of pixels, with a smaller pixel size with respect to the other outer layers, a front end ASIC (FE-I4) was designed. Because of its optimal performance, it was decided to adopt the IBL ROD also for Pixel Layer 1 and Layer 2. Among the several advantages, one of the most important is the reduction of link occupancy due to the increased bandwidth (80 Mb/s, two times the previous one). 40 ROD boards, fabricated and tested in 2015, were installed in the Layer 2 acquisition system featuring outstanding performance while 45 RODs for Layer 1 are still under test and will be installed by the end of 2016
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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