scholarly journals Wireless Temperature Sensing Using Permanent Magnets for Multiple Points Undergoing Repeatable Motions

2016 ◽  
Author(s):  
Yi Chen ◽  
Oksana Guba ◽  
Carlton F. Brooks ◽  
Christine C. Roberts ◽  
Bart G. van Bloemen Waanders ◽  
...  
Keyword(s):  
Dynamic Systems ◽  
Permanent Magnets ◽  
Multiple Points ◽  
Stationary Configuration ◽  
Calibration Methods ◽  
Slip Rings ◽  
Novel Method ◽  
End Effectors ◽  
New Applications ◽  
The Magnetic Field

Temperature monitoring is essential in automation, mechatronics, robotics and other dynamic systems. Wireless methods which can sense multiple temperatures at the same time without the use of cables or slip-rings can enable many new applications. A novel method utilizing small permanent magnets is presented for wirelessly measuring the temperature of multiple points moving in repeatable motions. The technique utilizes linear least squares inversion to separate the magnetic field contributions of each magnet as it changes temperature. The experimental setup and calibration methods are discussed. Initial experiments show that temperatures from 5 to 50 °C can be accurately tracked for three neodymium iron boron magnets in a stationary configuration and while traversing in arbitrary, repeatable trajectories. This work presents a new sensing capability that can be extended to tracking multiple temperatures inside opaque vessels, on rotating bearings, within batteries, or at the tip of complex end-effectors.

scholarly journals Review of methods for solving inverse problems in identifying permanent magnets of executive elements in dynamic devices

2018 ◽  
Vol 226 ◽  
pp. 04022 ◽  
Author(s):  
Anna L. Balaban ◽  
Yuri A. Bakhvalov ◽  
Peter A. Denisov
Keyword(s):  
Inverse Problems ◽  
Dynamic Systems ◽  
Permanent Magnets ◽  
Actual Problem ◽  
Small Perturbations ◽  
Mechanical Shocks ◽  
Ill Posed ◽  
Executive Elements ◽  
The Magnetic Field

Permanent magnets due to their overall-saving and energysaving properties are increasingly used in the executive elements in dynamic systems of various fields of technology (electric motors, electromagnetic drives, electromechanical devices – relays, contactors, etc.). At the same time, devices with permanent magnets have a disadvantage – under the effect of overheating, mechanical shocks and current surges in the windings, their demagnetization occurs, which can lead to disruption of operation and failure of devices. In this regard, there is a need for identification of permanent magnets, that is, assessment of their condition by investigating the distribution of the magnetization by the volume of the permanent magnets by using the solution of inverse problems. The article provides the overview of methods for solving such problems. The analysis of publications has shown that two approaches to the solution of inverse problems can be distinguished: – the linearization of some functional and the multiple solution of the direct problem of calculating the magnetic field; – solution of the ill-posed problem and determination of the pseudo-solution stable to small perturbations by regularization methods. Both approaches have disadvantages. For example, the application of mesh-based methods in field calculations leads to the need to solve systems of equations of large dimension, parallel calculations are not used, etc. Therefore, the improvement of methods for solving inverse problems in the identification permanent magnets of executive elements in dynamic devices is an actual problem.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

scholarly journals A Feasibility Study of a Noncontact Torque Sensor with Multiple Hall Sensors

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Kyungshik Lee ◽  
Chongdu Cho
Keyword(s):  
Magnetic Field ◽  
Permanent Magnets ◽  
Power Transmission ◽  
Magnetic Sensors ◽  
Torque Sensor ◽  
Torque Measurement ◽  
Test Range ◽  
Variable Power ◽  
Hall Sensors ◽  
The Magnetic Field

The feasibility of a noncontact sensor is investigated. This type of sensor can potentially be used for torque measurement in a speed-variable power transmission system. Torque can be read by examining the phase difference between two induction signals from respective magnetic sensors that detect the magnetic field intensity of permanent magnets mounted on the surface of a shaft in rotation. A real-time measuring algorithm that includes filtering and calibration is adopted to measure the torque magnitude. It is shown that this new torque sensor can perform well under rotation speeds ranging from 300 rpm to 500 rpm. As an interim report rather than a complete development, this work demonstrates the feasibility of noncontact torque measurement by monitoring a magnetic field. The result shows an error of less than 2% within the full test range, which is a sufficient competitive performance for commercial sensors. The price is very low compared to competitors in the marketplace, and the device does not require special handling of the shaft of the surface.

GUESS: projecting machine learning scores to well-calibrated probability estimates for clinical decision-making

2018 ◽  
Vol 35 (14) ◽  
pp. 2458-2465 ◽  
Author(s):  
Johanna Schwarz ◽  
Dominik Heider
Keyword(s):  
Machine Learning ◽  
Decision Support ◽  
Clinical Decision Support ◽  
State Of The Art ◽  
Clinical Decision Support Systems ◽  
Clinical Decision ◽  
Calibration Method ◽  
Probability Estimates ◽  
Calibration Methods ◽  
Novel Method

Abstract Motivation Clinical decision support systems have been applied in numerous fields, ranging from cancer survival toward drug resistance prediction. Nevertheless, clinical decision support systems typically have a caveat: many of them are perceived as black-boxes by non-experts and, unfortunately, the obtained scores cannot usually be interpreted as class probability estimates. In probability-focused medical applications, it is not sufficient to perform well with regards to discrimination and, consequently, various calibration methods have been developed to enable probabilistic interpretation. The aims of this study were (i) to develop a tool for fast and comparative analysis of different calibration methods, (ii) to demonstrate their limitations for the use on clinical data and (iii) to introduce our novel method GUESS. Results We compared the performances of two different state-of-the-art calibration methods, namely histogram binning and Bayesian Binning in Quantiles, as well as our novel method GUESS on both, simulated and real-world datasets. GUESS demonstrated calibration performance comparable to the state-of-the-art methods and always retained accurate class discrimination. GUESS showed superior calibration performance in small datasets and therefore may be an optimal calibration method for typical clinical datasets. Moreover, we provide a framework (CalibratR) for R, which can be used to identify the most suitable calibration method for novel datasets in a timely and efficient manner. Using calibrated probability estimates instead of original classifier scores will contribute to the acceptance and dissemination of machine learning based classification models in cost-sensitive applications, such as clinical research. Availability and implementation GUESS as part of CalibratR can be downloaded at CRAN.

scholarly journals Effect of Magnetic Water Treatment on Prevention of CaCO3 Scales

2013 ◽  
Vol 10 (1) ◽  
pp. 73-84
Author(s):  
Baghdad Science Journal
Keyword(s):  
Magnetic Field ◽  
Calcium Carbonate ◽  
Water Flow ◽  
Permanent Magnets ◽  
Thick Layer ◽  
Total Dissolved Solids ◽  
Magnetic Treatment ◽  
Magnetic Strength ◽  
Device Free ◽  
The Magnetic Field

Permanent magnets of different intensities were used to investigate the effect of a magnetic field in the process of preventing deposits of calcium carbonate. The magnets were fixed on the water line from the tap outside. Then heating a sample of this water in flasks and measuring the amount of sediment in a manner weighted differences. These experiments comprise to the change of the velocity of water flow, which amounted to (0.5, 0.75, 1) m/sec through the magnetic fields that are of magnetic strength (2200, 6000, 9250, 11000) Gauss, and conduct measurements, tests and compare them with those obtained from the use of ordinary water.The results showed the effectiveness of magnetic treatment in reducing the rate of deposition of calcium carbonate where up to 60% after treatment, and this percentage is increasing with increasing magnetic field strength where up to 85% when the intensity of the magnetic field 9250 and 11000 Gauss at the velocity of the water flow of 0.75 m/sec. This percentage of reducing was investigated with increasing the velocity of flow of water through a magnetic field. Also the results showed an increase in total dissolved solids (TDS) as well as electrical conductivity and a decrease in the value of surface tension as a result of magnetic treatment.Observation with the photograph pictures of the distillation apparatus oriented in several laboratories, that the amount of sediment formed a thick layer in the device-free magnetic treatment, but it was not dense and in the few quantity in the apparatus treated with magnetic intensity (8000, 9250) Gauss.

scholarly journals Magnetic Recording Method (MRM) for Nondestructive Evaluation of Ferromagnetic Materials

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 630
Author(s):  
Tomasz Chady ◽  
Ryszard D. Łukaszuk ◽  
Krzysztof Gorący ◽  
Marek J. Żwir
Keyword(s):  
Magnetic Field ◽  
Magnetic Recording ◽  
Permanent Magnets ◽  
Steel Structure ◽  
Standard Technique ◽  
Magnetic Field Measurement ◽  
Destructive Testing ◽  
Recording Method ◽  
Nondestructive Testing Method ◽  
The Magnetic Field

This paper proposes and experimentally investigates a novel nondestructive testing method for ferromagnetic elements monitoring, the Magnetic Recording Method (MRM). In this method, the inspected element must be magnetized in a strictly defined manner before operation. This can be achieved using an array of permanent magnets arranged to produce a quasi-sinusoidal magnetization path. The magnetic field caused by the original residual magnetization of the element is measured and stored for future reference. After the operation or loading, the magnetic field measurement is repeated. Analysis of relative changes in the magnetic field (for selected components) allows identifying applied stress. The proposed research methodology aims to provide information on the steel structure condition unambiguously and accurately. An interpretation of the results without referring to the original magnetization is also possible but could be less accurate. The method can be used as a standard technique for NDT (Non-Destructive Testing) or in structural health monitoring (SHM) systems.

scholarly journals Poly(catecholamine) Coating and Biofunctionalization of CsPbBr3 Microcrystals

2021 ◽  
Author(s):  
Sangyeon Cho ◽  
Seok-Hyun Yun
Keyword(s):  
Lipid Bilayers ◽  
Environmental Stability ◽  
Live Cells ◽  
Functional Coatings ◽  
Common Strategy ◽  
Novel Method ◽  
Halide Perovskites ◽  
The Stability ◽  
New Applications

<p>Lead halide perovskites (LHP) microcrystals are promising materials for various optoelectronic applications. Surface coating on particles is a common strategy to improve their functionality and environmental stability, but LHP is not amenable to most coating chemistries because of its intrinsic weakness against polar solvents. Here, we describe a novel method of synthesizing LHP microcrystals in a super-saturated polar solvent using sonochemistry and applying various functional coatings on individual microcrystals <i>in situ</i>. We synthesize cesium lead bromine perovskite (CsPbBr<sub>3</sub>) microparticles capped with organic poly-norepinephrine (pNE) layers. The catechol group of pNE coordinates to bromine-deficient lead atoms, forming a defect-passivating and diffusion-blocking shell. The pNE layer enhances the stability of CsPbBr<sub>3</sub> in water by 2,000-folds, enabling bright luminescence and lasing from single microcrystals in water. Furthermore, the pNE shell permits biofunctionalization with proteins, small molecules, and lipid bilayers. Luminescence from CsPbBr<sub>3</sub> microcrystals is sustained in water over 1 hour and observed in live cells. The functionalization method may enable new applications of LHP particles in water-rich environments.<b></b></p>

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