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magnetometer
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Consistent calibration of magnetometers for nonlinear attitude determination
, Article Measurement: Journal of the International Measurement Confederation ; Volume 73 , 2015 , Pages 180-190 ; 02632241 (ISSN) ; Pourtakdoust, S. H ; Sheikhy, A. A ; Sharif University of Technology
Elsevier
2015
Abstract
Abstract Three-axis magnetometers (TAMs) have been widely utilized as the cornerstone of integrated navigation (IN) and attitude determination (AD) in many aerospace systems. However, accurate navigation and AD demands for precise calibration of TAM. For this purpose, a complete TAM calibration process is presented in the current research to compensate all of the key errors. In this regard, a hyper least square (HyperLS) estimator is extended for accurate and consistent ellipsoid fitting problem of TAM calibration. Subsequently, the calibrated TAM is utilized for real time attitude determination via nonlinear colored noise filters of extended Kalman filter, simplex unscented Kalman filter...
Fundamental mode fluxgate magnetometers for active magnetic shielding
, Article 2011 19th Iranian Conference on Electrical Engineering, ICEE 2011, 17 May 2011 through 19 May 2011 ; May , 2011 , Page(s): 1 ; ISSN : 21647054 ; 9789644634284 (ISBN) ; Eshraghi, M. J ; Forooghi, F ; Sarreshtedari, F ; Fardmanesh, M ; Sharif University of Technology
2011
Abstract
Fluxgate magnetometers with different design and core materials have been made. The sensors have been characterized and the frequency responses of the sensors have been measured. The fluxgate magnetometer based on orthogonal design and amorphous wire core working in fundamental mode reaches 30pT/Hz noise level and 40μV/nT sensitivity. Finally an active magnetic shield constructed based on the amorphous core fluxgate magnetometer reaches more than 60dB field attenuation for DC field and has a good response for frequencies below 100Hz
Optimized design and implementation of low-cost, sensitive and versatile vibrating sample magnetometer
, Article ICEE 2012 - 20th Iranian Conference on Electrical Engineering, 15 May 2012 through 17 May 2012 ; May , 2012 , Pages 202-205 ; 9781467311489 (ISBN) ; Khiabani, S ; Sarreshtedari, F ; Fardmanesh, M ; Sharif University of Technology
2012
Abstract
Geometry of different electromagnetic parts of Vibrating Sample Magnetometer (VSM) is a major factor of VSM output voltage. In this paper design, geometry optimization and implementation of a sensitive, versatile and relatively inexpensive VSM system has been described. Considering all effective geometrical parameters in the system output voltage, the induced voltage in the pick-up coils has been obtained analytically and the geometry of the pick-up coils has been optimized for maximum output induced voltage. Two opposite series of pick-up coils, piezoelectric based vibration system and required electronic circuits have been designed and the VSM system has been implemented. The implemented...
Adaptive square-root cubature-quadrature Kalman particle filter via KLD-sampling for orbit determination
, Article Aerospace Science and Technology ; Volume 46 , October–November , 2015 , Pages 159-167 ; 12709638 (ISSN) ; Pourtakdoust, S. H ; Sharif University of Technology
Elsevier Masson SAS
2015
Abstract
Orbit determination (OD) problem utilizing onboard sensors is a key requirement for many current and future space missions. Though there exists ample research and work on this subject, a novel algorithm is presented in this paper for the nonlinear problem of OD. In this regard, initially a new cubature-quadrature particle filter (CQPF) that uses the square-root cubature-quadrature Kalman filter (SR-CQKF) to generate the importance proposal distribution is developed. The developed CQPF scheme avoids the limitation of the standard particle filter (PF) concerning new measurements. Subsequently, CQPF is enhanced to take advantage of the relative entropy (Kullback-Leibler Distance) criterion to...
Excitation current optimization of fluxgate magnetometers for active magnetic shielding of SQUID-based magnetocardiography system
, Article Journal of Superconductivity and Novel Magnetism ; Volume 30, Issue 8 , 2017 , Pages 2323-2328 ; 15571939 (ISSN) ; Kalantari, N ; Jabbari, T ; Fardmanesh, M ; Sharif University of Technology
Abstract
In order to achieve stable operation for a developed high-Tc SQUID-based magnetocardiography system, a two-stage active magnetic shielding technique is implemented. This technique is based on a combination of fluxgate and high-Tc SQUID magnetometers feedback loops. While two YBCO rf SQUIDs in a gradiometric configuration are used at liquid Nitrogen temperature as the main sensors for the heart signal detection and low-amplitude noise signals cancellation in one stage, a fluxgate is used to cancel large far-field environmental noise in the other stage feedback loop. The fluxgate sensors working in the fundamental mode under the optimized bias conditions have white noise levels less than 10...
Critical Current Density Optimization of High-T_c Superconductor
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mehdi (Supervisor)
Abstract
Fabrication of bulk superconductors with high critical current density widely has been studied because they have many applications, for example, Fault Current Limiter (SFCL), Superconducting Magnetic Energy Storage (SMES), and magnetic levitation. Providing pinning center by addings impurity into superconductor is usual and simple solution for increasing the superconductor critical current density. In this project we have fabricated superconductor YBCO bulk and optimized its critical current density. There are two major stream in this thesis, first design of Vibrating System Magnetization (VSM) for critical current measurements and then fabrication of YBCO bulk and optimization of its...
Design and Optimization of Magnetic Resonance Signal Detector to Enhancement of Sensitivity and SNR in Proton Precession Sensor
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mahdi (Supervisor)
Abstract
Proton precession is used in measurement of scalar magnetic field intensity. In this sensor, the magnetic field intensity is calculated through Larmor frequency using the proton precession frequency around the magnetic field. The accuracy of this sensor is in the range of picoTesla which is used for magnetic field measurement as well as the calibration of vector magnetic sensors. The signal to noise ratio in this sensor is due to the dimension and resistances of the wires and is a kind of RMS random noise. Although, changing the dimension of the wires for noise reduction and increasing the signal amplitude requires the fabrication of a bulky sensor with low power consumption. Therefore, it...
Excitation current optimization of fluxgate magnetometers for active magnetic shielding of SQUID-Based magnetocardiography system
, Article Journal of Superconductivity and Novel Magnetism ; 2016 , Pages 1-6 ; 15571939 (ISSN) ; Kalantari, N ; Jabbari, T ; Fardmanesh, M ; Sharif University of Technology
Springer New York LLC
Abstract
In order to achieve stable operation for a developed high-Tc SQUID-based magnetocardiography system, a two-stage active magnetic shielding technique is implemented. This technique is based on a combination of fluxgate and high-Tc SQUID magnetometers feedback loops. While two YBCO rf SQUIDs in a gradiometric configuration are used at liquid Nitrogen temperature as the main sensors for the heart signal detection and low-amplitude noise signals cancellation in one stage, a fluxgate is used to cancel large far-field environmental noise in the other stage feedback loop. The fluxgate sensors working in the fundamental mode under the optimized bias conditions have white noise levels less than 10...
Satellite Attitude Estimation Using MEMS
,
M.Sc. Thesis
Sharif University of Technology
;
Pourtakdoost, Hossein
(Supervisor)
Abstract
This thesis deals with the attitude estimation based on low cost sensor for a micro satellite in a circular, low earth orbit (LEO) and sensor calibration. With two body problem theory and Quaternion formulation, rotational motion is modeled. In addition gravity gradient effect is considered on satellite orbital elements. Using a 3-axis MEMS-based magnetometer and a sun sensor as two measurement systems, low cost attitude estimation is proposed. Bias and Scale factor are presented to model deterministic sensor error and white Gaussian noise to model stochastic sensor error. It is shown that by sensor calibration the estimation accuracy will improve. Non-linear estimation methods EKF, SRUKF...
Design & Implementation of Fluxgate Based Active Shield for Using in SQUID Based Magnetocardiograghy
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mehdi (Supervisor)
Abstract
Superconducting Quantum Interference Devices (SQUIDs) are one of the most sensitive magnetic flux detectors. According to their high sensitivity, these sensors have many applications such as magnetic imaging, magnetocardiography and magnetoencephalography. In this project we have designed and implemented a fluxgate based active shield that would be used in magnetocardiography. One of the main concerns in RF-SQUID applications is suppression of the low and high frequency noises. These noise sources includes earth magnetic force, humming noise and RF noise caused by cell phones. These sources could unlock RF-SQUID sensors and hence needs to be shielded. Low frequency noise suppression could be...
Design and Implementation of Vibrating Sample Magnetometer Based on Gradiometer RF SQUID
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mehdi (Supervisor)
Abstract
The aim of this project is design and implementation of the “gradiometer RF SQUID base Vibrating Sample Magnetometer (VSM)”. Different sections of the system have been designed such as pick up coils, vibration system and electronic circuits. The piezoelectric crystal has been concerned for vibration system. At the first step, we have implemented the basic VSM system. In the basic system, voltage induces in two series opposite pick up coils and its output is recognizable via electronic circuits. At the second phase of the project, the electronic circuits of basic VSM system have been replaced with the RF SQUID gradiometer and its electronic circuits. Afterwards, the sensitivity and the gain...
Design and Implementation of Proton Precession Magnetometer
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mahdi (Supervisor)
Abstract
Proton precession magnetometers are one of the most sensitive scalar magnetic sensors. Their function is based on Zeeman effect and also nuclear magnetic resonance phenomena. In this project we have designed and implemented needed coils, swithching and signal detection circuits. Because of extremely high sensitivity of this sensor to induced noises and also gradient of earth’s magnetic fileld, detection of precession signal needs design of low noise electronic circuits with special EMC considerations. The implemented system in this project contains different blocks, such as switching circuit and its related control unit, amplifier, filter and frequency meter. Using this system, the obtained...
Design and Fabrication of an Integrated Superconducting Resonator/Flux Concentrator for rf SQUID Magnetometer
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mahdi (Supervisor)
Abstract
Ultra-sensitive magnetometers based on Radio Frequency Superconducting Quantum Interference Device (rf SQUID), have wide applications in Non-destructive Evaluation (NDE), geophysical measurements and biomagnetic measurements, especially in magnetocardiography (MCG) systems. A superconducting module coupled to rf SQUID is designed to provide a resonance frequency in GHz range (according to the electronic system frequency), as well as concentrating the magnetic flux in the effective area of SQUID. The signal can be measured through a port pumping AC power to the module. The resonator has been also implemented by lumped element tank circuits, but the quality factor of these circuits are usually...
Integrated Magnetometer-Horizon Sensor Low-Earth-Orbit Determination
, M.Sc. Thesis Sharif University of Technology ; Asadian, Nima (Supervisor)
Abstract
In this thesis, the orbit determination of Low Earth Orbits (LEO) using the integrated magnetometer and horizon sensor data has been investigated. Orbit determination is an essential part of a space mission. Not only the modeling, guidance, navigation and control errors may results in error in injecting the satellite into its nominal orbit, the environmental disturbances deviate the satellite from its predicted orbit and from an operational perspective most satellites need continuous orbit determination. Traditionally, ground based orbit determination is used which are non-autonomous and expensive and just can be used for specific times which the satellite can be observed from the ground...
Integrated magnetometer-horizon sensor low-earth orbit determination using UKF
, Article Acta Astronautica ; Volume 106 , January–February , 2015 , Pages 13-23 ; 00945765 (ISSN) ; Assadian, N ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
The estimation of the satellite orbital elements using the integrated magnetometer and horizon sensors data has been investigated in this study. These sensors are generally employed for attitude estimation. The magnetometer and the horizon sensor measure the Earths magnetic field as well as the Earths center direction in the body frame, respectively. The magnitude of the magnetic field and the angle between two vectors have been used for orbit estimation purpose. This excludes the knowledge of the attitude in the orbit determination. The Gaussian variation of parameters equations is used for the orbital motion dynamical model to have the orbital elements as the states of the system. Since...
Effect of rf pumping frequency and RF input power on the flux to voltage transfer function of rf-SQUIDs
, Article IEEE Transactions on Applied Superconductivity ; Volume 17, Issue 2 , 2007 , Pages 676-679 ; 10518223 (ISSN) ; Eker, T ; Bozbey, A ; Fardmanesh, M ; Schubert, J ; Banzet, M ; Sharif University of Technology
2007
Abstract
We present the results on the correlation between the flux to voltage transfer function, Vspp, of the rf-SQUID and the rf-bias frequency as well as rf-bias power. Measurements were performed for different SQUID gradiometer samples chosen from the same batch or different batches. In order to have full control on the electronics parameters, an experimental rf-SQUID circuit was designed and implemented with an operation frequency of 600 MHz to 900 MHz. According to our findings, It has been observed that at any particular rf-bias power, Vspp vs. rf-bias frequency shows Sine-like behavior. We observed that the main lobe maxima exist close to the resonance frequency of the LC tank circuit and by...
Induced magnetic anisotropy in Fe0.7Co0.3 fine particles
, Article Journal of Physics D: Applied Physics ; Volume 39, Issue 23 , 2006 , Pages 4925-4929 ; 00223727 (ISSN) ; Zoriasatain, S ; Amirhoseini, M ; Akhavan, M ; Sharif University of Technology
2006
Abstract
In FeCo fine particles, induced anisotropy has a considerable contribution in increasing the coercivity. We have prepared Fe0.7Co0.3 fine particles by the borohydride method in the presence of various magnetic fields in the range 0 ≤ H0 ≤ 2 kOe. We have studied and analysed the factors affecting the induced anisotropy and magnetic structure of these particles by the use of SEM, XRD and vibrating sample magnetometer. It was found that heat treatment, and also the presence of a magnetic field of about 1 kOe during the grain growth, result in the maximum coercivity of Fe 0.7Co0.3 fine particles. The value of magnetic field intensity should be such that it causes formation of oriented atomic...
The set-up of a high temperature superconductor radio-frequency SQUID microscope for magnetic nanoparticle detection
, Article Superconductor Science and Technology ; Volume 19, Issue 5 , 2006 , Pages S261-S265 ; 09532048 (ISSN) ; Krause, H. J ; Banzet, M ; Lomparski, D ; Schubert, J ; Zander, W ; Zhang, Y ; Akram, R ; Fardmanesh, M ; Sharif University of Technology
2006
Abstract
SQUID (superconducting quantum interference device) microscopes are versatile instruments for biosensing applications, in particular for magnetic nanoparticle detection in immunoassay experiments. We are developing a SQUID microscope based on an HTS rf SQUID magnetometer sensor with a substrate resonator. For the cryogenic set-up, a configuration was realized in which the cryostat is continuously refilled and kept at a constant liquid nitrogen level by an isolated tube connection to a large liquid nitrogen reservoir. The SQUID is mounted on top of a sapphire finger, connected to the inner vessel of the stainless steel cryostat. The vacuum gap between the cold SQUID and room temperature...
Structural and soft magnetic properties of nanocrystalline Fe 85Si10Ni5 powders prepared by mechanical alloying
, Article Materials Letters ; Volume 60, Issue 8 , 2006 , Pages 1068-1070 ; 0167577X (ISSN) ; Madaah Hosseini, H. R ; Abachi, P ; Miraghaei, S ; Sharif University of Technology
2006
Abstract
In this investigation, fine Fe85Si10Ni5 (at.%) powders with a nanocrystalline structure were prepared by high energy ball milling. The effects of milling time on microstructure and magnetic properties of Fe85Si10Ni5 powders were studied by X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The optimum soft magnetic properties (maximum saturation magnetization and minimum coercivity) were obtained in alloy powders with an average grain size of 8 nm after 70 h milling. © 2005 Elsevier B.V. All rights reserved
Concurrent orbit and attitude estimation using minimum sigma point unscented Kalman filter
, Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Vol. 228, issue. 6 , 2014 , p. 801-819 ; Pourtakdoust, S. H ; Sharif University of Technology
Abstract
Concurrent orbit and attitude determination (COAD) plays a key role in reducing the cost of navigation and control subsystem for small satellites. This article is devoted to the problem of the COAD of satellites. A measurement package consisting of three axis magnetometer (TAM) and a sun sensor is shown to be sufficient to estimate the attitude and orbit information. To this end, an autonomous gyro-less COAD algorithm is proposed and implemented through the centralized data fusion of the TAM and the sun sensor. The set of nonlinear-coupled roto-translation dynamics of the satellite is used with a modified unscented Kalman filter (MUKF) to estimate the full satellite states. The MUKF is...