scholarly journals Performance Characterization of the Smartphone Video Guidance Sensor as Vision-Based Positioning System

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5299
Author(s):  
Nasir Hariri ◽  
Hector Gutierrez ◽  
John Rakoczy ◽  
Richard Howard ◽  
Ivan Bertaska
Keyword(s):  
Sampling Rate ◽  
Target Velocity ◽  
Error Statistics ◽  
Operational Conditions ◽  
Error Metrics ◽  
Orientation Vector ◽  
State Position ◽  
Overall Performance ◽  
Video Guidance

The Smartphone Video Guidance Sensor (SVGS) is a vision-based sensor that computes the six-state position and orientation vector of a target relative to a coordinate system attached to a smartphone. This paper presents accuracy-characterization measurements of the Smartphone Video Guidance Sensor (SVGS) to assess its performance as a position and attitude estimator, evaluating its accuracy in linear and angular motion for different velocities and various types of targets based on the mean and standard deviation errors between SVGS estimates and known motion profiles, in both linear and angular motions. The study also examines the effects of target velocity and sampling rate on the overall performance of SVGS and provides an overall assessment of SVGS’ performance as a position/attitude estimator. While the error metrics are dependent on range and camera resolution, the results of this paper can be scaled to other operational conditions by scaling the blob size in pixels (the light markers identified in the images) relative to the total resolution (number of pixels) of the image. The error statistics of SVGS enable its incorporation (by synthesis of a Kalman estimator) in advanced motion-control systems for navigation and guidance.

Design, Fabrication, and Characterization of a Soft Multi-Fingered Hand

2016 ◽  
Author(s):  
Lena Johnson ◽  
Hugh A. Bruck ◽  
Satyandra K. Gupta
Keyword(s):  
Geometric Model ◽  
Design Parameters ◽  
Experimental Setup ◽  
Robotic Hand ◽  
Iterative Design ◽  
Modeling Methods ◽  
Design And Manufacturing ◽  
Overall Performance ◽  
Fabrication And Characterization

This paper describes the design, fabrication, testing and modeling of the SUR Hand. The SUR Hand is a soft, under actuated robotic hand. Through an iterative design and manufacturing process, SUR Hand’s soft, actuating components have been adapted from the original PneuFlex, pneumatically actuated finger to be highly flexible and capable of actuating a precision force. This paper shows how altering the design parameters of the fingers altered their overall performance. Furthermore, it details the experimental setup for testing the components, as well as the modeling methods used. Finally, it shows the process for creating and validating a geometric model that characterizes proper grasping strategies, assuming a passive palm component.

AC Magnetic Measurements on Superconductors

2013 ◽  
pp. 208-222
Author(s):  
Philippe Laurent ◽  
Jean-François Fagnard ◽  
Philippe Vanderbemden
Keyword(s):  
Magnetic Properties ◽  
Temperature Distribution ◽  
Magnetic Measurements ◽  
Sampling Rate ◽  
Data Acquisition System ◽  
Magnetic Data ◽  
Magnetic Characterization ◽  
Set Up ◽  
Cryogenic Conditions

This work describes the design and realisation of an apparatus to measure simultaneously the AC magnetic properties and the temperature distribution on the top surface of bulk superconducting samples (up to 32 mm in diameter) in cryogenic conditions (temperature range 78-120 K). First the authors describe the experimental set-up used for simultaneous thermal and magnetic characterization of the sample. Next, the authors describe the practical considerations required for generating the large AC magnetic fields, possibly in the presence of DC fields. Then the authors present the data acquisition system allowing both temperature and magnetic data to be recorded at high a sampling rate.” The performances and limitations of the system are discussed.

AC Magnetic Measurements on Superconductors

2011 ◽  
Vol 1 (3) ◽  
pp. 53-66
Author(s):  
Philippe Laurent ◽  
Jean-François Fagnard ◽  
Philippe Vanderbemden
Keyword(s):  
Magnetic Properties ◽  
Temperature Distribution ◽  
Magnetic Measurements ◽  
Sampling Rate ◽  
Data Acquisition System ◽  
Magnetic Data ◽  
Magnetic Characterization ◽  
Set Up ◽  
Cryogenic Conditions

This work describes the design and realisation of an apparatus to measure simultaneously the AC magnetic properties and the temperature distribution on the top surface of bulk superconducting samples (up to 32 mm in diameter) in cryogenic conditions (temperature range 78-120 K). First the authors describe the experimental set-up used for simultaneous thermal and magnetic characterization of the sample. Next, the authors describe the practical considerations required for generating the large AC magnetic fields, possibly in the presence of DC fields. Then the authors present the data acquisition system allowing both temperature and magnetic data to be recorded at high a sampling rate." The performances and limitations of the system are discussed.

Freight Railroads Adjacent to High-Speed Rail: Assessing the Risk

2014 ◽  
Author(s):  
John Cockle
Keyword(s):  
High Speed ◽  
Objective Assessment ◽  
Assessment Model ◽  
Exact Probability ◽  
High Speed Rail ◽  
Operational Conditions ◽  
Hazard Risk ◽  
Class 1 ◽  
Potential Applications

By law, the California High-Speed Train System (CHSTS) must be designed and built along established transportation corridors, includes adjacent to or in shared right-of-ways with Class 1 freight railroads. The Adjacent Railroad Hazard Risk Assessment Model (ARHRAM) has been developed as a tool to assist the California High-Speed Rail Authority (Authority) in the assessment of hazard risk posed by adjacent freight railroads. This assessment assists the Authority in the risk-based prioritization of resources meant to mitigate the hazards presented by the adjacency of freight railroad operations. Use of the ARHRAM allows the Authority to apply consistent, objective assessment techniques across the entire system and throughout the various developmental phases. ARHRAM uses both quantitative and qualitative techniques to develop a characterization of the hazard risk at a particular location, as opposed to an exact probability of the occurrence of a derailment. FRA-reportable derailment data is used to establish the frequency of a derailment on the adjacent railroad at any location, normalized against the performance over a 10-year period. A review of characteristics at a particular location is then conducted, examining for the presence of sixteen separate site characteristics including alignment geometry, train control methods, speed, access, grade crossings, special trackwork, and operational modes. Each characteristic is given a value according to its presence (or not) and the total multiplied by the derailment factor for the railroad and volume of trains operated at the location. The result is a characterization of the levels of site-specific hazard risk that allows the Authority to prioritize mitigations (resources) in order to reduce risk to an acceptable level. The model is dynamic in that it can be modified if new characteristics need to be introduced or existing characteristics modified, and the model can be re-run should physical or operational conditions change in the future. This paper applies the model to an existing rail corridor adjacent the CHSTS, demonstrating how appropriate mitigations can be determined and residual risk accepted. The paper also identifies future applications of the ARHRAM in the development of the CHSTS, and potential applications for other systems or modes.

scholarly journals Assessing the Influence of the Sourcing Voltage on Polyaniline Composites for Stress Sensing Applications

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1164 ◽  
Author(s):  
Andrés Felipe Cruz-Pacheco ◽  
Leonel Paredes-Madrid ◽  
Jahir Orozco ◽  
Jairo Alberto Gómez-Cuaspud ◽  
Carlos R. Batista-Rodríguez ◽  
...  
Keyword(s):  
Operating Voltage ◽  
Mechanical Mixing ◽  
Sensing Applications ◽  
Error Metrics ◽  
Strain Stress ◽  
Stress Sensing ◽  
Polyaniline Composites ◽  
Ultra High Molecular Weight ◽  
Effective Distribution

Polyaniline (PANI) has recently gained great attention due to its outstanding electrical properties and ease of processability; these characteristics make it ideal for the manufacturing of polymer blends. In this study, the processing and piezoresistive characterization of polymer composites resulting from the blend of PANI with ultra-high molecular weight polyethylene (UHMWPE) in different weight percentages (wt %) is reported. The PANI/UHMWPE composites were uniformly homogenized by mechanical mixing and the pellets were manufactured by compression molding. A total of four pellets were manufactured, with PANI percentages of 20, 25, 30 and 35 wt %. Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to confirm the effective distribution of PANI and UHMWPE particles in the pellets. A piezoresistive characterization was performed on the basis of compressive forces at different voltages; it was found that the error metrics of hysteresis and drift were influenced by the operating voltage. In general, larger voltages lowered the error metrics, but a reduction in sensor sensitivity came along with voltage increments. In an attempt to explain such a phenomenon, the authors developed a microscopic model for the piezoresistive response of PANI composites, aiming towards a broader usage of PANI composites in strain/stress sensing applications as an alternative to carbonaceous materials.

scholarly journals Rainfall Estimation Accuracy of a Nationwide Instantaneously Sampling Commercial Microwave Link Network: Error Dependency on Known Characteristics

2019 ◽  
Vol 36 (7) ◽  
pp. 1267-1283 ◽  
Author(s):  
L. W. de Vos ◽  
A. Overeem ◽  
H. Leijnse ◽  
R. Uijlenhoet
Keyword(s):  
Coefficient Of Variation ◽  
Rainfall Intensity ◽  
Sampling Rate ◽  
Early Morning ◽  
Estimation Accuracy ◽  
Signal Attenuation ◽  
Late Night ◽  
Instantaneous Sampling ◽  
Overall Performance ◽  
Microwave Link

AbstractCommercial microwave links are installed and maintained for the purpose of telecommunication. Hydrometeors between transmitting and receiving antennas cause the microwave signal to be attenuated. From signal attenuation, the path-averaged rainfall intensity can be calculated. A 7-month dataset of instantaneously logged signal powers from almost 2000 unique links in the Netherlands is analyzed. Rainfall intensities are calculated with the RAINLINK package with a novel preprocessing module, enabling the package to be applied on instantaneously logged data from now on. Rainfall intensities per link are validated with the path-averaged rainfall intensities according to a gauge-adjusted radar product. Both the overall performance and the dependence of errors on link characteristics and measurement conditions are evaluated. The coefficient of variation decreases from 3.70 to 2.32 and the correlation increases from 0.30 to 0.63 from instantaneous to daily estimates of rainfall accumulations. The coefficient of variation is also smaller during heavy rainfall. Errors are largest for pathlengths shorter than 2 km, for observations during the late night and early morning, and for observations during colder months (when solid or melting precipitation could occur and dew is more likely to form on the antennas). Comparison of our results with those of earlier studies shows that minimum/maximum sampling (widely employed in network management systems) outperforms instantaneous sampling regarding detection of both quantity and occurrence of rain at a 15-min sampling rate in the Dutch climate.

Characterization of Cathode Chromium Incorporation during Mid-Term Stack Operation under Various Operational Conditions

2019 ◽  
Vol 7 (1) ◽  
pp. 245-254 ◽  
Author(s):  
Norbert H. Menzler ◽  
L. G. de Haart ◽  
Doris Sebold
Keyword(s):  
Operational Conditions

scholarly journals Synthesis and characterization of modified activated carbon (MgO/AC) for methylene blue adsorption: optimization, equilibrium isotherm and kinetic studies

2021 ◽  
Author(s):  
Vahab Ghalehkhondabi ◽  
Alireza Fazlali ◽  
Keyhan Ketabi
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Natural Waters ◽  
Sol Gel ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Human Beings ◽  
Operational Conditions ◽  
Coating Method

Abstract Methylene blue (MB) is the cationic dye that is widely used for coloring cotton, wool, and silk. Since MB is harmful to human beings and toxic to microorganisms, there is the need to find cheap and efficient methods for removal of MB from wastewater prior to disposal into natural waters. In the present study, MB adsorption potential of MgO/AC prepared using a sol–gel-thermal deep-coating method was compared with the activated carbon (AC). The central composite design (CCD) as a method of the response surface methodology (RSM) was applied to minimize the number of runs and process optimization. The characterization of the microporous MgO/AC composite showed that the magnesium oxide nanoparticles were successfully coated on the AC and the BET specific surface area of AC and MgO/AC were 1,540 and 1,246 m2/g, respectively. The MB removal efficiency and the maximum adsorption capacity of AC and MgO/AC were 89.6, 97.5% and 571.7, 642.3 mg/g, respectively under optimum operational conditions of initial dye concentration of 100.9 mg/L, the adsorbent dosage of 69.4 mg/100 mL, pH of 10.2 and contact time of 149.1 min. According to an analysis of variance (ANOVA), the initial dye concentration and its interaction with the other effective factors have a large impact on adsorption efficiency. Furthermore, the mechanism of adsorption followed the Langmuir isotherm (R2 = 0.9935, Δqe = 2.9%) and adsorption kinetics fitted by the pseudo-second-order model (R2 = 0.9967, Δqe = 6.6%). Finally, our results suggest that the prepared MgO/AC is an efficient and promising material for dye wastewater treatment.

Centimeter-scale-resolution airborne temperature measurements in clouds and in marine surface layer during EUREC4A 

2021 ◽  
Author(s):  
Stanisław Król ◽  
Szymon Malinowski ◽  
Wojciech Kumala ◽  
Jakub Nowak ◽  
Robert Grosz ◽  
...  
Keyword(s):  
Surface Layer ◽  
Sampling Rate ◽  
Temperature Measurements ◽  
Small Scale ◽  
Temperature Structure ◽  
Scale Temperature ◽  
Marine Surface Layer ◽  
Marine Surface ◽  
Temperature Records

<p><span>Characterization of small-scale temperature structure of convective clouds and their environment is crucial to understand turbulent entrainment, mixing and its effect on cloud dynamics and microphysics. A newly constructed ultra-fast thermometer UFT2, developed from the former UFT-M, allowing for temperature measurements in clouds with the resolution better than few centimeters, was deployed on the British Antarctic Survey Twin-Otter research aircraft in the course of the EUREC4A research campaign. The goal was to perform first ever fine-scale temperature characterization of subtropical marine warm cumulus clouds.</span></p><p><span>The prototype instrument worked relatively well and allow to collect data from 7 of 17 research flights, including hundreds of cloud penetrations and segments of flights in the marine surface layer. Data, collected with 20 kHz sampling rate, after filtering and averaging allowed to achieve physical resolution of ~3cm at ~60m/s true air speed of the aircraft.</span></p><p><span>Performance of the UFT-2 sensor and its calibration will be discussed. The discussion will be illustrated with examples of multi-scale temperature records collected in cloud interiors, cloud edges, cloud shells at various altitudes as well as in the marine surface layer ~30 m above the sea level.</span></p>

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