International Journal of Applied Electromagnetics and Mechanics - Volume 28, issue 1-2

Authors: Takeno, Takanori | Miki, Hiroyuki | Takagi, Toshiyuki

Article Type: Research Article

Abstract: Tungsten-containing diamond-like carbon (W-DLC) film was investigated with the aim of strain sensor application. Three samples deposited under different methane flow rates were investigated. The strain dependence of normalized resistance has a linear dependence and the gauge factor has positive and negative values. The sensitivity and temperature coefficient of resistance (TCR) increase with an increase in the methane flow rate. However, from a practical point of view the sample with the lowest gauge factor is most …appropriate for a stain sensor because it has the smallest TCR of the three samples. Show more

Keywords: Diamond-like carbon (DLC), strain sensor, Tungsten metal

DOI: 10.3233/JAE-2008-978

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 211-217, 2008

Authors: Lee, Byung-Jun | Jo, Won-Young | Li, Jian | Koo, Dae-Hyun | Cho, Yun-Hyun

Article Type: Research Article

Abstract: This paper presents the dynamic vibration analysis of axial-flux permanent magnet synchronous machines(AFPMSMs). The major sources of vibration in electric machines such as motors and generators are the magnetic force and mechanical geometric shape. To decrease the mechanical vibration in AFPMSMs, we proposed an advanced design method considering the coupled-field analysis of the electromagnetic and mechanical problems encountered for both the rotor and stator. By the proposed method, the AFPMSM was analyzed, and characteristics …such as the magnetic force, natural frequencies, mode shapes, and deformation were studied. This study has accomplished the dynamic vibration analysis of AFPMSMs. Show more

Keywords: Axial flux motor, vibration, finite element methods, natural frequency, magnetic force

DOI: 10.3233/JAE-2008-979

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 219-225, 2008

Authors: Choi, Jae-Hak | Koo, Dae-Hyun | Kim, Sol | Kim, Youn-Hyun | Ahn, Joonseon | Cho, Chang-Hyun | Lee, Ju

Article Type: Research Article

Abstract: This paper presents an approximate optimization to maximize efficiency and power factor of high speed Single Phase Switched Reluctance Motor (SPSRM) in vacuum cleaner. Moreover, an optimum design process for SPSRM has been performed with geometric and electric parameters by using Response Surface Methodology and 2-D Finite Element Method that is coupled with the circuit equation of the rectifier and converter. To confirm the propriety of the Finite Element Method and the motor performance, simulation waveforms …and experiment waveforms for motor voltage and current were compared. Show more

Keywords: Approximate optimization, response surface methodology, single phase switched reluctance motor

DOI: 10.3233/JAE-2008-980

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 227-235, 2008

Authors: Choi, Jae-Hak | Chun, Yon-Do | Han, Pil-Wan | Kim, Sol | Kim, Youn-Hyun | Ahn, Joonseon | Kim, Yong-Su | Lee, Ju

Article Type: Research Article

Abstract: This paper deals with a practical methodology to optimize a reading probe of data storage devices using polarization in electric field. The tip and angle of probe pole between a probe and a medium are adopted and identified as significant design variables that have an effect on the polarization direction. The proposed sensitivity function and optimum resistive reading probe shape in the electric recording devices could be obtained by using Response Surface Method and Finite Element …Method. Show more

Keywords: Electrical recording, reciprocity principles, response surface method, resistive reading probe

DOI: 10.3233/JAE-2008-981

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 237-245, 2008

Authors: Kim, Youn-Hyun | Kim, Sol | Choi, Jae-Hak | Ahn, Joonseon | Cho, Chang-Hyun | Lee, Ju

Article Type: Research Article

Abstract: Large torque ripple of the Switched Reluctance Motor (SRM) is a major problem that is an obstacle to spreading over an industry. Nonlinear inductance profile and pulse magnetizing make the torque ripple unavoidable. In order to reduce the torque ripple, it is necessary to control the torque directly because the torque of the SRM is not linearly proportional to a current. This paper shows direct torque control scheme that reduces the torque ripple of the SRM …dramatically. To verify the feasibility of control scheme, simulation and experiment are carried out. Show more

Keywords: Direct Torque Control (DTC), Non-interference Current Control (NICC), Switched Reluctance Motor (SRM), torque ripple minimization

DOI: 10.3233/JAE-2008-982

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 247-253, 2008

Authors: Ahn, Joonseon | Choi, Jae-Hak | Go, Sung Chul | Kim, Sol | Kim, Yun-Hyun | Choi, Jae-Hoon | Lee, Ju

Article Type: Research Article

Abstract: This paper presents a sensorless algorithm of the synchronous reluctance motor(SynRM). Conventionally flux estimation method using phase voltage integration has problem in low speed operation. This is due to insufficient terminal voltage in that speed. However in high speed operation, it is enough to estimate rotor flux. Therefore in this paper the current model which uses phase current signal is proposed to compensate the insufficiency of terminal voltage in low speed to estimate rotor position. Computer …simulations are performed to confirm the adequacy of the proposed control scheme. The experiments are also performed for verification of proposed algorithm. Show more

Keywords: Synchronous reluctance motor, SynRM, sensorless control, flux estimation

DOI: 10.3233/JAE-2008-983

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 255-266, 2008

Authors: Nagaya, Kosuke | Kobayashi, Kazuya | Nenoi, Masaomi | Hosokawa, Yuhki | Murakami, Iwanori

Article Type: Research Article

Abstract: A new type valve system using a conical spring and an permanent-electromagnetic actuator was developed. The system uses a conical spring whose spring constant is low in small valve displacement, but increases with the displacement of the valve due to its nonlinear property. The system has a permanent-electromagnet which compresses the valve spring under electromagnetic control. The valve system is used without electric current in low cam speeds. Therefore, driving energy is small in low cam …speeds because of spring constant being small. However, the jump and bounce phenomena occur in the high-speed cam rotation region. Those are suppressed by using a permanent-electromagnetic actuator that consists of two permanent magnets and an electromagnet. The actuator strengthens the restoration force of the spring by the electromagnetic repulsion force, and controls the jump phenomenon. Both analytical and experimental checks have been made for the proposed system. It was confirmed that, by using the system with the permanent-electromagnetic actuator, the jump and bounce phenomena were suppressed, and driving torques were also decreased. Show more

DOI: 10.3233/JAE-2008-984

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 267-273, 2008

Authors: Kim, Mi-Jung | Kim, Byong-Kuk | Moon, Ji-Woo | Cho, Yun-Hyun | Hwang, Don-Ha | Kang, Dong-Sik

Article Type: Research Article

Abstract: In this study, we propose a diagnosis method for the rotor eccentricity in induction machines fed by a PWM converter by considering the harmonics in a transient magnetic phenomenon. The influences of the asymmetrical whirling motions are studied using the back EMF of a search coil, which enables the detection of motor faults. The analysis results of the rotor eccentricity could be obtained by comparing the characteristics of motors fabricated with normal and irregular air gaps, …and the validity is verified from the experimental results. The simulation and experimental results can be useful for the online faults detection monitoring system of induction machines. Show more

DOI: 10.3233/JAE-2008-985

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 275-281, 2008

Authors: Zhu, Yu-Wu | Kim, Do-Sun | Moon, Ji-Woo | Cho, Yun-Hyun

Article Type: Research Article

Abstract: A permanent magnet linear synchronous motor (PMLSM) is most suitable for fast, high-precision dynamic control systems. However, a significant drawback of PMLSM is the thrust ripple that deteriorates the performance of the drive system. This paper first presents a simple design for a PMLSM. Next, the thrust ripple is predicted by the finite element method (FEM) and it is fitted by a Fourier series using a curve fitting method. Finally, an advance field oriented control (FOC) …method is used to compensate this thrust ripple by injecting an appropriate current. The effectiveness of this proposed thrust ripple suppression method is verified by the numerical results. Show more

Keywords: Permanent magnet linear synchronous motor, detent force, field oriented control, fourier series curve fitting method, current compensation

DOI: 10.3233/JAE-2008-986

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 283-289, 2008

Authors: Elshafiey, Ibrahim | Alkanhal, Majeed | Algarni, Ayed

Article Type: Research Article

Abstract: Recent advances in instrumentation and signal processing allow the acquisition of eddy current NDE signal in the form of c-san images. A technique is presented in this paper to enhance eddy current inspection based on multi-spectral, multi-temporal, and multi-resolution image fusion. The developed algorithm is motivated by human eye perception of colored objects. Mathematically it is based on the IHS transform, as well as the shift invariant wavelet analysis. Quality of resulting fusion images is evaluated …based on statistical image quality metrics. Show more

Keywords: Eddy current, NDE, wavelet analysis, image fusion

DOI: 10.3233/JAE-2008-987

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 291-296, 2008

Authors: Cacciola, Matteo | Deng, Yiming | Morabito, Francesco C. | Udpa, Lalita | Udpa, Satish | Versaci, Mario

Article Type: Research Article

Abstract: Magneto Optic Imaging is a relatively recent Non Destructive Evaluation technique, successfully used to evaluate the integrity of metallic parts in aging aircrafts. In this paper, the authors deal with the implementation of a suitable procedure able to recognize flawed rivets in Magneto Optic measurements. They have been carried out at the NDE Lab, Michigan State University, USA. Exploiting Fuzzy Subtractive Clustering in order to implement the classifier, our proposed approach retrieves a fast and robust …applicative, useful for real-time applications. Preliminary results are really encouraging. Show more

Keywords: Magneto optic images, fuzzy clustering, flawed rivet identification

DOI: 10.3233/JAE-2008-988

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 297-303, 2008

Authors: Kumar, Mrityunjay | Ramuhalli, Pradeep

Article Type: Research Article

Abstract: Data fusion techniques have been used extensively in several application areas, including nondestructive evaluation (NDE) applications. This paper proposes a probability density based pixel-level fusion algorithm for NDE applications. The proposed approach models the fusion process as a convex combination of input data. The model parameters are estimated by optimizing the Kullback-Leibler distance between the density functions of the fused and the input data. Preliminary results on multimodal eddy current NDE data from …aircraft lap joints indicate the feasibility of the proposed approach. Show more

Keywords: Image fusion, aircraft lap joint, pixel-level fusion

DOI: 10.3233/JAE-2008-989

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 305-311, 2008

Authors: Demachi, Kazuyuki | Rybalko, Sergei | Yusa, Noritaka

Article Type: Research Article

Abstract: This paper proposes the method to detect and diagnose the defects of the rotating wings of turbines, pumps and motors by the measuring the change of the eddy currents comparing with those of no defects. The eddy current is induced in the conductor wings rotating in the static magnetic field and the magnetic field by the eddy current is measured by a pick-up coil. The magnetic field are obviously different between the wings with/without the defects. This …method has the possibility of contribution to the earlier findings of the defects of the abnormality of the turbines, pumps and motors. Moreover, the time-series of the horizontal displacement of the rotating axis was measured by the laser displacement meter. To the axis, the external magnetic force was applied by a ring magnet to make the unstable state. The SSA (Singular Spectrum Analysis) [2] was applied to analyze the time-series of the displacement in the unstable state and it was shown that some of the SSA components are sensitive enough for the earlier detection of the transition to the unstable state. Show more

Keywords: Eddy current, diagnosis method, singular spectral analysis

DOI: 10.3233/JAE-2008-990

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 313-320, 2008

Authors: Calcagno, S. | Cardelli, E. | Faba, A. | Formisano, A. | Martone, R. | Morabito, F.C. | Papais, M. | Pirani, A. | Ricci, M. | Specogna, R. | Tamburrino, A. | Trevisan, F. | Versaci, M. | Ventre, S.

Article Type: Research Article

Abstract: The AMDE project ("Applicazioni di Metodi per Diagnostica Elettromagnetica", in English "Applied Methods for Electromagnetic Evaluation") is an Italian two-years national granted research project on electromagnetic non-destructive evaluation. This project involves five different research units located in Italy, about twenty researchers and ten among Ph.D. students and post-doc. Here we focus on the contribution of the AMDE project to the reconstruction of 3D volumetric defects in metallic plates as those used in …aeronautical and aerospace industry. In particular, in this work we propose an efficient numerical model for evaluating the field due to volumetric anomalies and an inversion method based on the Total Variation Regularization. Numerical examples confirm the capability of the proposed strategy to reconstruct 3D volumetric defects. Show more

Keywords: Eddy current testing, numerical methods, total variation regularization, inverse problems

DOI: 10.3233/JAE-2008-991

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 321-327, 2008

Authors: Tamburrino, A. | Ventre, S. | Ferrigno, L. | Udpa, S.

Article Type: Research Article

Abstract: The aim of this work is to describe an eddy current non-destructive testing system employing Giant Magnetoresistive (GMR) sensors. GMR sensors are solid state devices capable of measuring the magnetic flux density. The use of GMR sensors in the framework of eddy current testing is motivated by their intrinsically high sensitivity, large bandwidth and low cost. This paper is specifically focused on the development of a GMR based probe integrated into an eddy current testing system …for detecting the presence of millimeters size cracks in highly conductive materials such as Aluminum. Show more

Keywords: Eddy current testing, giant magneto resistance

DOI: 10.3233/JAE-2008-992

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 329-336, 2008