1,570 research outputs found
A high speed Tri-Vision system for automotive applications
Purpose: Cameras are excellent ways of non-invasively monitoring the interior and exterior of vehicles. In particular, high speed stereovision and multivision systems are important for transport applications such as driver eye tracking or collision avoidance. This paper addresses the synchronisation problem which arises when multivision camera systems are used to capture the high speed motion common in such applications.
Methods: An experimental, high-speed tri-vision camera system intended for real-time driver eye-blink and saccade measurement was designed, developed, implemented and tested using prototype, ultra-high dynamic range, automotive-grade image sensors specifically developed by E2V (formerly Atmel) Grenoble SA as part of the European FP6 project – sensation (advanced sensor development for attention stress, vigilance and sleep/wakefulness monitoring).
Results : The developed system can sustain frame rates of 59.8 Hz at the full stereovision resolution of 1280 × 480 but this can reach 750 Hz when a 10 k pixel Region of Interest (ROI) is used, with a maximum global shutter speed of 1/48000 s and a shutter efficiency of 99.7%. The data can be reliably transmitted uncompressed over standard copper Camera-Link® cables over 5 metres. The synchronisation error between the left and right stereo images is less than 100 ps and this has been verified both electrically and optically. Synchronisation is automatically established at boot-up and maintained during resolution changes. A third camera in the set can be configured independently. The dynamic range of the 10bit sensors exceeds 123 dB with a spectral sensitivity extending well into the infra-red range.
Conclusion: The system was subjected to a comprehensive testing protocol, which confirms that the salient requirements for the driver monitoring application are adequately met and in some respects, exceeded. The synchronisation technique presented may also benefit several other automotive stereovision applications including near and far-field obstacle detection and collision avoidance, road condition monitoring and others.Partially funded by the EU FP6 through the IST-507231 SENSATION project.peer-reviewe
Software Defined Networks based Smart Grid Communication: A Comprehensive Survey
The current power grid is no longer a feasible solution due to
ever-increasing user demand of electricity, old infrastructure, and reliability
issues and thus require transformation to a better grid a.k.a., smart grid
(SG). The key features that distinguish SG from the conventional electrical
power grid are its capability to perform two-way communication, demand side
management, and real time pricing. Despite all these advantages that SG will
bring, there are certain issues which are specific to SG communication system.
For instance, network management of current SG systems is complex, time
consuming, and done manually. Moreover, SG communication (SGC) system is built
on different vendor specific devices and protocols. Therefore, the current SG
systems are not protocol independent, thus leading to interoperability issue.
Software defined network (SDN) has been proposed to monitor and manage the
communication networks globally. This article serves as a comprehensive survey
on SDN-based SGC. In this article, we first discuss taxonomy of advantages of
SDNbased SGC.We then discuss SDN-based SGC architectures, along with case
studies. Our article provides an in-depth discussion on routing schemes for
SDN-based SGC. We also provide detailed survey of security and privacy schemes
applied to SDN-based SGC. We furthermore present challenges, open issues, and
future research directions related to SDN-based SGC.Comment: Accepte
NIKEL: Electronics and data acquisition for kilopixels kinetic inductance camera
A prototype of digital frequency multiplexing electronics allowing the real
time monitoring of microwave kinetic inductance detector (MKIDs) arrays for
mm-wave astronomy has been developed. Thanks to the frequency multiplexing, it
can monitor simultaneously 400 pixels over a 500 MHz bandwidth and requires
only two coaxial cables for instrumenting such a large array. The chosen
solution and the performances achieved are presented in this paper.Comment: 21 pages, 14 figure
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Application of Advanced Early Warning Systems with Adaptive Protection
This project developed and field-tested two methods of Adaptive Protection systems utilizing synchrophasor data. One method detects conditions of system stress that can lead to unintended relay operation, and initiates a supervisory signal to modify relay response in real time to avoid false trips. The second method detects the possibility of false trips of impedance relays as stable system swings “encroach” on the relays’ impedance zones, and produces an early warning so that relay engineers can re-evaluate relay settings. In addition, real-time synchrophasor data produced by this project was used to develop advanced visualization techniques for display of synchrophasor data to utility operators and engineers
NIKEL_AMC: Readout electronics for the NIKA2 experiment
The New Iram Kid Arrays-2 (NIKA2) instrument has recently been installed at
the IRAM 30 m telescope. NIKA2 is a state-of-art instrument dedicated to
mm-wave astronomy using microwave kinetic inductance detectors (KID) as
sensors. The three arrays installed in the camera, two at 1.25 mm and one at
2.05 mm, feature a total of 3300 KIDs. To instrument these large array of
detectors, a specifically designed electronics, composed of 20 readout boards
and hosted in three microTCA crates, has been developed. The implemented
solution and the achieved performances are presented in this paper. We find
that multiplexing factors of up to 400 detectors per board can be achieved with
homogeneous performance across boards in real observing conditions, and a
factor of more than 3 decrease in volume with respect to previous generations.Comment: 21 pages; 16 figure
Evaluation of a Modular PET System Architecture with Synchronization over Data Links
A DAQ architecture for a PET system is presented that focuses on modularity, scalability and reusability. The system defines two basic building blocks: data acquisitors and concentra- tors, which can be replicated in order to build a complete DAQ of variable size. Acquisition modules contain a scintillating crystal and either a position-sensitive photomultiplier (PSPMT) or an array of silicon photomultipliers (SiPM). The detector signals are processed by AMIC, an integrated analog front-end that generates programmable analog outputs which contain the first few statistical moments of the light distribution in the scintillator. These signals are digitized at 156.25 Msamples/s with free-run- ning ADCs and sent to an FPGA which detects single gamma events, extracts position and time information online using digital algorithms, and submits these data to a concentrator module. Concentrator modules collect single events from acquisition modules and perform coincidence detection and data aggregation. A synchronization scheme over data links is implemented that calibrates each link s latency independently, ensuring that there are no limitations on module mobility, and that the architecture is arbitrarily scalable. Prototype boards with both acquisition and concentration functionality have been built for evaluation pur- poses. The performance of a small PET system with two detectors based on continuous scintillators is presented. A synchronization error below 50 ps rms is measured, and energy resolutions of 19% and 24% and timing resolutions of 2.0 ns and 4.7 ns FWHM are obtained for PMT and SiPM photodetectors, respectively.Manuscript received June 25, 2013; revised November 06, 2013; accepted January 03, 2014. Date of publication January 29, 2014; date of current version February 06, 2014. This work was supported in part by the Spanish Ministry of Science and Innovation under CICYT Grant FIS2010-21216-C02-02.Aliaga Varea, RJ.; Herrero Bosch, V.; MonzĂł Ferrer, JM.; Ros GarcĂa, A.; Gadea GironĂ©s, R.; Colom Palero, RJ. (2014). Evaluation of a Modular PET System Architecture with Synchronization over Data Links. IEEE Transactions on Nuclear Science. 61(1):88-98. https://doi.org/10.1109/TNS.2014.2298399S889861
EMMNet: Sensor Networking for Electricity Meter Monitoring
Smart sensors are emerging as a promising technology for a large number of application domains. This paper presents a collection of requirements and guidelines that serve as a basis for a general smart sensor architecture to monitor electricity meters. It also presents an electricity meter monitoring network, named EMMNet, comprised of data collectors, data concentrators, hand-held devices, a centralized server, and clients. EMMNet provides long-distance communication capabilities, which make it suitable suitable for complex urban environments. In addition, the operational cost of EMMNet is low, compared with other existing remote meter monitoring systems based on GPRS. A new dynamic tree protocol based on the application requirements which can significantly improve the reliability of the network is also proposed. We are currently conducting tests on five networks and investigating network problems for further improvements. Evaluation results indicate that EMMNet enhances the efficiency and accuracy in the reading, recording, and calibration of electricity meters
A NASA family of minicomputer systems, Appendix A
This investigation was undertaken to establish sufficient specifications, or standards, for minicomputer hardware and software to provide NASA with realizable economics in quantity purchases, interchangeability of minicomputers, software, storage and peripherals, and a uniformly high quality. The standards will define minicomputer system component types, each specialized to its intended NASA application, in as many levels of capacity as required
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