1,721,121 research outputs found
Clamp-and-Forget: A self-sustainable non-invasive wireless sensor node for smart metering applications
No full textMeasuring andmanagingthepowerconsumptionofhouseholdappliances,aswellasthatofindustrial
machineries, isbecomingmoreandmoreimportanttoimprovethedistributionandusageofthe
electrical energyandtoreducetheenergybill.Wepresentthedesignofanon-invasivewirelesscurrent
meter whichcanmeasureACcurrentupto60ARMS exploitingasmallclamp-oninductivesensor.The
noveltyofthedesignisasubsystemconsistingofaharvestingcircuitdesignedtoextractenergyfrom
the samecurrenttransducerusedformeasurements.Experimentshavebeenconductedtovalidatethe
approach, toassesstheaccuracyofthesensingsystemanddeviationsduetotheenergyharvester,andto
determine theconditionwhichpermitsustoachievetheenergyneutralityandthus,aself-sustainable
smart meter
Benefits of wake-up radio in energy-efficient multimodal surveillance wireless sensor network
No full textScarce energy budget of battery-powered wireless
sensor nodes calls for cautious power management not to
compromise performance of the system. To reduce both energy
consumption and delay in energy-hungry wireless sensor networks
for latency-restricted surveillance scenarios, this paper
proposes a multimodal two-tier architecture with wake-up radio
receivers. In video surveillance applications, using information
from distributed low-power pyroelectric infrared (PIR) sensors
which detect human presence limits the activity of cameras and
reduces their energy consumption. PIR sensors transmit the
information about the event to camera nodes using wake-up radio
receivers. We show the benefits of wake-up receivers over dutycycling
in terms of overcoming energy consumption vs. latency
trade-off (proved with two orders of magnitude lower latency
– only 9 ms). At the same time, the power consumption of the
camera node including a wake-up receiver is comparable with
the one having only duty-cycled main transceiver with 1% duty
cycle (about 32 mW for 25 activations per hour)
Ensuring survivability of resource-intensive sensor networks through ultra-low power overlays
No full textNodes in wireless sensor networks (WSNs) typically
have limited power supply and networks are often expected to be
functional for extended periods. Therefore, the minimization of
energy consumption and the maximization of network lifetime are
key objectives in WSN. This paper proposes an overlay, energy
optimized, sensor network to extend the functional lifetime of an
energy-intensive sensor network application. The overlay network
consists of additional nodes that exploit recent advances in energy
harvesting and wake-up radio technologies, coupled with an application
specific, complementary, ultra-low power sensor. The experimental
results and simulations demonstrate that this approach can
ensure survivability of energy-inefficient sensor networks. Simulating
applications using energy-intensive video cameras and air
quality sensors, combined with the proposed overlayed ultra-low
power sensor network, demonstrates that this approach can increase
functional lifetime toward perpetual operation and is suitable
for WSN applications in which complementarity exists between the
required energy-intensive sensors and low-cost sensors that can be
used as triggers
A Thermoelectric Powered System for Skiing Performance Monitoring
No full textPervasive and wearable devices are becoming more and more common and important in the growing market of Internet of Things. Still the implementations of these devices are often not energy aware, lacking in optimization and ignoring the possibility of energy harvesting. Here we present a novel prototype of wearable device, conceived for skiing monitoring, that exploits the potential of thermoelectric harvesting in a mountain climate environment
Design Considerations for Wireless Acquisition of Multichannel sEMG Signals in Prosthetic Hand Control
No full textWearable technology for assistive medical applications and physical activity recognition has emerged as a fast growing research field in recent years. However, the design of such systems still poses challenges, including restricted physical size, limited computational resources, and the availability of constrained energy sources. In this paper, we present a practical design space exploration of a body-worn system for prosthetic hand control based on surface electromyography (sEMG) signals. The sEMG method is a well-established sensing technology that provides the detection of electrical activity produced by the physiological contractions of muscles. The presented wearable system is designed to acquire sEMG signals for successive recognition of the performed motion and the control of the prosthetic hand, allowing to regain a considerable amount of life quality for a broad patient community. The main guiding requirements for the presented wearable system include real-time data acquisition from up to 32 sEMG channels, reliable wireless data streaming, long mobile autonomy (several days lifetime), non-intrusive mounting, and compact size. We present the system’s hardware and software architecture focusing on the comparison of various communication design options such as recent Bluetooth low energy and low-power WiFi technologies
Non-invasive voltage measurement in a three-phase autonomous meter
No full textMonitoring current and voltage waveforms is essential to evaluate the energy consumption of a system and to improve its efficiency. In this paper we present a smart meter for power consumption which can measure both current and voltage without any physical contact to the electric load or to the conductors of the power cables. This makes the power metering much safer and easier; furthermore an energy harvesting module based on inductive coupling provides power supply to the meter without any need of batteries or plugs to the mains. We describe the innovative contact-less voltage measurement system, which is based on capacitive coupling and uses an algorithm with two pre-processing channels for self-calibration and to provide accurate measurements regardless the cable type. The three-phase version is capable of measuring the three-phase power consumption of an electric load in a complete contact-less manner. In comparison with commercial high-cost instruments, experimental results of our low-cost smart meter demonstrate similar high performance with maximum 3Â % deviation from the reference value
Implementation of phasor measurement units on low-cost embedded platforms: A feasibility study
No full textThe Phasor Measurement Units (PMUs) are currently considered among the most useful instruments for smart grid monitoring. While the traditional PMUs deployed at the transmission level are usually high-performance and expensive instruments, the interest in smaller and cheaper units able to perform synchronized measurements of voltage and current waveforms at the distribution level is currently growing. In this paper, a feasibility study about the implementation of state-of-the-art estimation algorithms for PMUs in low-cost embedded platforms is presented. The proposed approach relies on an Interpolated Discrete Fourier Transform (IpDFT) for static frequency offset estimation followed by a modified Taylor-Fourier Transform (TFT) for waveform amplitude, phase, frequency and rate of change of frequency (ROCOF) estimation under dynamic conditions. Both algorithms, implemented in C++, run on a Beagle-Bone Black board. After evaluating the total computation time as a function of both the sampling rate and the number of observed cycles, a criterion to choose the data acquisition stage is described. Finally, the accuracy of synchrophasor, frequency and ROCOF estimators is determined by emulating most of the testing conditions reported in the IEEE Standards C37.118.1-2011 and C37.118.1a-2014
Wake up for Power Line Communication in Street Lighting Networks
No full textStreet lighting is responsible of a big share of electricity consumption of a city. The modernization of such a big network is required to meet the needs of energy saving for the future Smart City, helping to reach a reduction of greenhouse gas emissions also. In this work, we introduce a wake-up system, which permits to reduce the power consumption of receiving modem in power line communication, with particular attention to street lighting networks. Experimental and simulation results will show the optimal parameter configuration necessary to the system
Flora Monitoring with a Plant-Microbial Fuel Cell
No full textPlant-Microbial Fuel Cells are a promising technology as energy supplier for many different applications in precision agriculture and environmental monitoring. In this article, we discuss and analyze the possibility to use it also a small scale biosensor to monitor a plant health and report information with an embedded wireless sensor node. We present a prototype that exploits the electric energy generated by bacteria to power the embedded electronics and some sensors, while the rate of energy generation is used as a feedback on plant’s health state
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