scholarly journals Perrogator: A Portable Energy-Efficient Interrogator for Dynamic Monitoring of Wavelength-Based Sensors in Wearable Applications

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2962 ◽  
Author(s):  
Camilo A. R. Diaz ◽  
Arnaldo Gomes Leal-Junior ◽  
Letícia M. Avellar ◽  
Paulo F. C. Antunes ◽  
Maria J. Pontes ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Energy Efficient ◽  
Axial Strain ◽  
Healthy Person ◽  
Tunable Filter ◽  
Dynamic Monitoring ◽  
Wavelength Shift ◽  
Knee Angle ◽  
Single Board Computer ◽  
Good Agreement

In this paper, we report the development of a portable energy-efficient interrogator (Perrogator) for wavelength-based optical sensors. The interrogator is based on a compact solution encompassing a white light source and the spectral convolution between the sensor and a tunable filter, which is acquired by a photodetector, where a microcontroller has two functions: (i) To control the filter tuning and to (ii) acquire the photodetector signal. Then, the data is sent to a single-board computer for further signal processing. Furthermore, the employed single-board computer has a Wi-Fi module, which can be used to send the sensors data to the cloud. The proposed approach resulted in an interrogator with a resolution as high as 3.82 pm (for 15.64 nm sweeping range) and maximum acquisition frequency of about 210 Hz (with lower resolution ~15.30 pm). Perrogator was compared with a commercial fiber Bragg grating (FBG) interrogator for strain measurements and good agreement between both devices was found (1.226 pm/µε for the commercial interrogator and 1.201 pm/µε for the proposed approach with root mean square error of 0.0144 and 0.0153, respectively), where the Perrogator has the additional advantages of lower cost, higher portability and lower energy consumption. In order to demonstrate such advantages in conjunction with the high acquisition frequency allowed us to demonstrate two wearable applications using the proposed interrogation device over FBG and Fabry-Perot interferometer (FPI) sensors. In the first application, an FBG-embedded smart textile for knee angle assessment was used to analyze the gait of a healthy person. Due to the capability of reconstructing the FBG spectra, it was possible to employ a technique based on the FBG wavelength shift and reflectivity to decouple the effects of the bending angle and axial strain on the FBG response. The measurement of the knee angle as well as the estimation of the angular and axial displacements on the grating that can be correlated to the variations of the knee center of rotation were performed. In the second application, a FPI was embedded in a chest band for simultaneous measurement of breath and heart rates, where good agreement (error below 5%) was found with the reference sensors in all analyzed cases.

scholarly journals The relationship between photometric and spectroscopic oscillation amplitudes from 3D stellar atmosphere simulations

2021 ◽  
Author(s):  
Yixiao Zhou ◽  
Thomas Nordlander ◽  
Luca Casagrande ◽  
Meridith Joyce ◽  
Yaguang Li ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Three Dimensional ◽  
Quantitative Relationship ◽  
Stellar Atmospheres ◽  
Spectral Lines ◽  
Wavelength Shift ◽  
The Sun ◽  
Theoretical Derivation ◽  
Velocity Amplitude ◽  
Good Agreement

Abstract We establish a quantitative relationship between photometric and spectroscopic detections of solar-like oscillations using ab initio, three-dimensional (3D), hydrodynamical numerical simulations of stellar atmospheres. We present a theoretical derivation as proof of concept for our method. We perform realistic spectral line formation calculations to quantify the ratio between luminosity and radial velocity amplitude for two case studies: the Sun and the red giant ε Tau. Luminosity amplitudes are computed based on the bolometric flux predicted by 3D simulations with granulation background modelled the same way as asteroseismic observations. Radial velocity amplitudes are determined from the wavelength shift of synthesized spectral lines with methods closely resembling those used in BiSON and SONG observations. Consequently, the theoretical luminosity to radial velocity amplitude ratios are directly comparable with corresponding observations. For the Sun, we predict theoretical ratios of 21.0 and 23.7 ppm/[m s−1] from BiSON and SONG respectively, in good agreement with observations 19.1 and 21.6 ppm/[m s−1]. For ε Tau, we predict K2 and SONG ratios of 48.4 ppm/[m s−1], again in good agreement with observations 42.2 ppm/[m s−1], and much improved over the result from conventional empirical scaling relations which gives 23.2 ppm/[m s−1]. This study thus opens the path towards a quantitative understanding of solar-like oscillations, via detailed modelling of 3D stellar atmospheres.

Wavelength Interrogator for Optical Sensors Based on a Novel Thermo-Optic Tunable Filter in SOI

2012 ◽  
Vol 30 (13) ◽  
pp. 2143-2150 ◽  
Author(s):  
Vittorio M. N. Passaro ◽  
Andrei V. Tsarev ◽  
Francesco De Leonardis
Keyword(s):  
Optical Sensors ◽  
Tunable Filter

Energy Efficient Microcontroller Based Wireless Transceiver Module for Robotic Vehicle

2015 ◽  
Vol 793 ◽  
pp. 549-553
Author(s):  
Muhammad Bilal Sarwar ◽  
N. Perumal ◽  
Zuhairi Baharudin ◽  
Mohana Sundaram Muthuvalu
Keyword(s):  
Low Power ◽  
Energy Efficient ◽  
Cost Effective ◽  
Low Power Consumption ◽  
Power Cost ◽  
Communication Signals ◽  
Wireless Transceiver ◽  
Transceiver Module ◽  
Robotic Vehicle ◽  
Good Agreement

A low power, cost effective and energy efficient microcontroller (PIC 16F877A) based transceiver model has been presented. The designed model entails a combination of programmable microcontroller and relay circuitry to control the robotic vehicle through transceiver module. The model was simulated in a Mikro C environment, for communication signals from controlling side. The simulation results show an energy efficiency of 73%, with a distance of 20 meters for robotic vehicle. The results are in good agreement with theoretical understandings and show a greater efficiency, with low power consumption and reduced complexity. The simulations are found recurrent with stable findings and deemed compatible for applications.

scholarly journals Frequency-Tunable and Pattern Diversity Antennas for Cognitive Radio Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
A. H. Ramadan ◽  
J. Costantine ◽  
Y. Tawk ◽  
C. G. Christodoulou ◽  
K. Y. Kabalan
Keyword(s):  
Cognitive Radio ◽  
Bandpass Filter ◽  
Microstrip Antennas ◽  
Open Loop ◽  
Tunable Filter ◽  
Radiation Characteristics ◽  
Wideband Antenna ◽  
Pattern Diversity ◽  
Frequency Tunable ◽  
Good Agreement

Frequency-tunable microstrip antennas, for cognitive radio applications, are proposed herein. The approach is based on tuning the operating frequency of a bandpass filter that is incorporated into a wideband antenna. The integration of an open loop resonator- (OLR-) based adjustable bandpass filter into a wideband antenna to transform it into a tunable filter-antenna is presented. The same technique is employed to design a cognitive radio pattern diversity tunable filter-antenna. A good agreement between the simulated and measured results for the fabricated prototypes is obtained. The radiation characteristics of each designed tunable filter-antenna are included herein.

Low-cost electromyograph combined with markerless pose detection

2021 ◽  
Vol 88 (s1) ◽  
pp. s71-s76
Author(s):  
Florian Scheible ◽  
Raphael Lamprecht ◽  
Marc Rives ◽  
Alexander Sutor
Keyword(s):  
Computer Vision ◽  
Muscle Activity ◽  
Low Cost ◽  
Image Data ◽  
Knee Angle ◽  
Pose Detection ◽  
The Subject ◽  
Sample Rate ◽  
Good Agreement

Abstract This papers presents a low-cost electromyograph combined with marker-less pose detection using computer vision. The developed and build three channel electromyograph is tested by measuring the muscle activity of one leg, while the subject is performing squats. Simultaneously, a camera records the exercise and subsequently the image data is evaluated by OpenPose. We could show that this simple setup enables the user to evaluate the muscle activity of three independent muscles as function of the knee angle. These results are in good agreement to the expected muscle activity. The sample-rate of the EMG device is 2 kHz. The overall cost of the developed device is under 100 €. To our knowledge, this is the first work combining these two methods for dynamic exercises. The method is well customizable for other sports due to the battery powered device and its handy size.

Electronically Reconfigurable Varactor-Loaded HMSIW Bandpass Filter

Frequenz ◽  
2018 ◽  
Vol 72 (5-6) ◽  
pp. 227-230
Author(s):  
Jing-Pan Song ◽  
Xin-Yi Wang ◽  
Feng Wei ◽  
Xiao-Wei Shi
Keyword(s):  
Reverse Bias ◽  
Tuning Range ◽  
Bandpass Filter ◽  
Tunable Filter ◽  
Ring Resonators ◽  
Reverse Bias Voltage ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Filter Size ◽  
Good Agreement

AbstractA varactor-loaded half-mode substrate integrated waveguide (HMSIW) reconfigurable bandpass filter (BPF) is proposed in this paper. The proposed BPF is composed of complementary split-ring resonators (CSRRs) and varactors. Meanwhile, a nonmetalized via is employed in the center of the CSRR. It is noted that the varactor is embedded into the nonmetalized via, which can significantly reduce the tunable filter size. By changing the reverse bias voltage of the varactor, the resonant frequency of the proposed filter can be adjusted. Moreover, low insert loss (IL) and wide tuning range can be achieved. In order to validate its practicability, a BPF with the frequency ranging from 1.9 GHz to 2.5 GHz is fabricated and good agreement between the simulated and measured results is observed.

CFD Simulation of Incompressible Turbomachinery — A Comparison of Results From ANSYS Fluent and OpenFOAM

2014 ◽  
Author(s):  
Franziska Bothe ◽  
Christian Friebe ◽  
Martin Heinrich ◽  
Rüdiger Schwarze
Keyword(s):  
Flow Field ◽  
Energy Efficient ◽  
Total Pressure ◽  
High Performance ◽  
Cfd Simulation ◽  
Pressure Rise ◽  
Wake Flow ◽  
Ansys Fluent ◽  
Simulation Results ◽  
Good Agreement

A numerical investigation of incompressible turbomachinery and the comparison of two CFD packages are presented within this paper. A ducted single rotor fan is simulated with OpenFOAM and ANSYS FLUENT by applying methods as comparable as possible. The characteristic maps and flow fields are analyzed and the results from the CFD codes are compared to examine differences regarding accuracy and efficiency. Additionally the influence of the turbulence model is determined. It is found that the CFD programs show a good agreement especially at the machines design point. The information about the flow field of this fan is used for the modelling of a high-performance and energy-efficient ducted contra-rotating fan (CRF). Comparing the CRF simulation results to those of the single rotor fan, a doubling of the total pressure rise and a significant reduction of the swirl in the wake flow can be noticed.

Wavelength-Division Multiplexing Fiber Bragg Grating Vibration Sensing Demodulation System

2013 ◽  
Vol 718-720 ◽  
pp. 636-640
Author(s):  
Fang Dong Zhu ◽  
Dong Sheng Zhang ◽  
Yong Xing Guo ◽  
Li Tong Li
Keyword(s):  
Fiber Laser ◽  
Fiber Bragg Grating ◽  
Wavelength Division Multiplexing ◽  
Tunable Filter ◽  
Vibration Measurement ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Wavelength Division ◽  
Vibration Sensors ◽  
Vibration Sensing

A fiber Bragg grating (FBG) sensing network for vibration measurement is proposed and demonstrated in this paper. The light source of the described sensing technique is an erbium-doped fiber laser applying a 980-nm laser diode and a fiber Fabry-Perot tunable filter. The fiber laser has a 40nm tuning range, allowing many vibration sensors to be multiplexed on the same fiber. Reflected light wavelength shift of the FBG sensor caused by strain variation is converted to intensity deviation, which avoids a complex demodulation process. This sensing scheme can effectively increase the demodulation speed of sensing system up to 20 KHz. At least 20 FBGs can be multiplexed alone a fiber.

Predicting vertical luminous efficacy using horizontal solar data

2001 ◽  
Vol 33 (1) ◽  
pp. 25-42 ◽  
Author(s):  
DHW Li ◽  
JC Lam
Keyword(s):  
Energy Efficient ◽  
Model Development ◽  
Measured Data ◽  
Luminous Efficacy ◽  
Energy Efficient Buildings ◽  
Proposed Model ◽  
Hourly Data ◽  
Surface Models ◽  
Inclined Surface ◽  
Good Agreement

Daylighting is recognized as an important and useful strategy in the design of energy-efficient buildings. Daylight illuminance, particularly on vertical surfaces, plays a major role in determining and evaluating the daylighting performance of a building. Luminous efficacy approach is considered as a versatile and easily applied way to calculate outdoor illuminance. This paper presents an approach to estimate the vertical outdoor illuminance from computed vertical luminous efficacy based on the measured horizontal solar irradiance and illuminance data. Hourly data recorded from January 1996 to December 1998 in Hong Kong were used for the model development. The performance of the proposed model and two well-known anisotropic inclined surface models (Muneer and Perez) was evaluated against data measured in 1999. Statistical analysis indicated that the proposed model gives reasonably good agreement with measured data for all vertical planes. The proposed model can provide an alternative to building designers in estimating the vertical solar illuminance and irradiance where only the horizontal measurements are available.

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