International Journal of Applied Electromagnetics and Mechanics - Volume 39, issue 1-4

Authors: Abidi, Zakia | Bandelier, Bernard | Djennah, Mohammed | Rioux-Damidau, Françoise

Article Type: Research Article

Abstract: A numerical technique, based on the combination of a finite element method and a boundary integral method has been developed to compute the induced signal in MRI antennas. This signal rises from a free movement of precession of the transverse magnetization of the sample to explore. In our modeling, the transverse magnetization represents the magnetic source field. Its flux embraces the antenna to give rise to a sinusoidal current which is very quickly attenuated in time …(a few ms); it represents the signal containing all the informations of the sample. We here want to find the geometrical and electromagnetic characteristics of the antennas which permit to have a signal to noise ratio as great as possible. In our computation, we have taken into account leading factors such as the distance between the probe and the organ to be explored and also the geometrical and electromagnetic characteristics of the probe. Show more

Keywords: MRI antennas, boundary integral method, finite element method

DOI: 10.3233/JAE-2012-1535

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 725-731, 2012

Authors: Han, Pil-Wan | Chun, Yon-Do | Choi, Jae-Hak | Seo, Un-Jae | Koo, Dae-Yun | Lee, Ju | Lee, Won-Goo

Article Type: Research Article

Abstract: The characteristics of an induction motor vary depending upon the number of parameters and the performance relationship between the parameters is also implicit. In the case of the induction motor design, we should generally estimate the many objective physical quantities in the optimization procedure. In this article, the multi objective design optimization based on a genetic algorithm is applied for a three phase induction motor. The efficiency, starting torque, and material cost are selected as the …objectives. The validity of the design results is also clarified by comparison between the calculated results and the measured ones. Show more

Keywords: High-efficiency, cost, optimization, genetic algorithm

DOI: 10.3233/JAE-2012-1536

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 733-737, 2012

Authors: Ito, Yasuhisa | Igarashi, Hajime | Watanabe, Kota | Iijima, Yosuke | Kawano, Kenji

Article Type: Research Article

Abstract: This paper presents a non-conforming finite element (FE) method with tetrahedral elements, which is applied to 3-D shape optimization. In the present method, continuity of magnetic flux is directly enforced on the interfaces of different domains in which FE meshes are independently generated. The slave unknowns in one side which are linearly dependent on the unknowns in the other side are eliminated. It is shown that the present method yields accurate solutions to 3-D nonlinear magnetostatic …problems. Moreover, evolutional shape optimization of an inductor is shown to be successfully carried out using the present method. Show more

Keywords: Finite element method, non-conforming element, genetic algorithm, optimization

DOI: 10.3233/JAE-2012-1537

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 739-745, 2012

Authors: Watanabe, Yuta | Watanabe, Kota | Igarashi, Hajime

Article Type: Research Article

Abstract: This paper presents multi-objective optimization of meander line antennas (MLA) for passive UHF-band Radio Frequency Identification. The characteristics of the MLA loaded by Cockcroft-Walton (CW) circuit are analyzed by hybrid analysis of the finite difference time domain method and modified nodal analysis. The antenna shape is optimized in order to maximize the output voltage of the CW circuit and minimize the antenna size.

Keywords: Pareto optimization, SPEA2, UHF-band passive RFID, FDTD, antenna optimization

DOI: 10.3233/JAE-2012-1538

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 747-752, 2012

Authors: Beddek, K. | Clénet, S. | Moreau, O. | Le Menach, Y.

Article Type: Research Article

Abstract: In this paper, a spectral stochastic finite element method (SSFEM) is described and applied to quantify uncertainties in an industrial eddy current non destructive testing (NDT) problem. A new iterative solver based on the fixed-point method is proposed to solve the large scale linear system. The efficiency of the suggested iterative solver to tackle the SSFEM computational complexity is demonstrated. The SSFEM results and the computation times obtained with 2 and 4 random variables are compared …to those given by the anisotropic adaptive sparse grid non intrusive spectral projection (NISP). On this application, the SSFEM dedicated solver is competitive with the adaptive sparse grids strategy. Show more

Keywords: Spectral stochastic finite element method, fixed-point method, eddy current problem, polynomial chaos expansion, intrusive solver

DOI: 10.3233/JAE-2012-1539

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 753-760, 2012

Authors: Sato, Takahiro | Watanabe, Kota | Igarashi, Hajime | Iijima, Yosuke | Kawano, Kenji

Article Type: Research Article

Abstract: In parameter optimization using the finite element method (FEM), re-meshing with long computational time must be performed many times. Although voxel-based FEM is one of the effective techniques to avoid the re-meshing, it has less accuracy in comparison with the conventional FEM because of stair-shaped boundaries. In this work, to improve the computational accuracy in the voxel-based FEM, a new homogenization method is presented. In the present method, the effective reluctivity of finite elements at material …interfaces is determined on the basis of magnetic circuit. The present method is successfully applied to three dimensional shape optimization of an inductor model. Show more

Keywords: Voxel-based finite element method, optimization, homogenization

DOI: 10.3233/JAE-2012-1540

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 761-768, 2012

Authors: Li, Hao | Yang, Baokun | Yan, Guirong | Hu, Junwen

Article Type: Research Article

Abstract: A new approach to vibration control simulation for electrodynamic shakers was developed using an electromagnetic finite element method (FEM) model. This approach consisted of two parts. First, the electromagnetic coupling FEM model of the shaker was developed using vibration theory and electromagnetic theory. The electromagnetic force was described using the Maxwell stress tensor, and the electromagnetic field distribution and the dynamic response of the shaker were calculated numerically using FEM. Second, the …vibration control simulation system was established: the shaker was described using an electromagnetic FEM model, and the controller was described with an adaptive inverse algorithm. As an example, control simulation of a 1-ton electrodynamic shaker was conducted. The results demonstrate the validity of this approach and provide a basis for the controller design of electrodynamic shakers. Show more

Keywords: Electromagnetic FEM, electrodynamic shaker, adaptive inverse control

DOI: 10.3233/JAE-2012-1541

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 769-777, 2012

Authors: Bartolomeo, Luca | Lin, Zhuohua | Sessa, Salvatore | Zecca, Massimiliano | Ishii, Hiroyuki | Takanishi, Atsuo

Article Type: Research Article

Abstract: In the last years there has been increasing interest on Inertial Measurement Units (IMUs) in several fields, because they can provide a measurement of the orientation, velocity, and acceleration at low cost with high performance. The main reason of the low cost is the possibility to find inertial sensors, as accelerometers, gyroscopes and magnetometers, based on Micro-Electro-Mechanical Systems (MEMS) made by silicon, with further advantages of small dimensions and mass production from the main semiconductor …suppliers. In this paper, we present the development of the ultra miniaturized wireless IMU, WB-4 (Waseda Bioinstrumentation number 4), with a 3-axis accelerometer, 3-axis gyroscope and 3-axis magnetometer. Additionally, we illustrate, together with results, the algorithms used for the data filtering and calibration, with particular emphasis on a new methodology for the online calibration of the digital magnetometer. Show more

Keywords: Inertial Measurement Unit, wireless, magnetic calibration

DOI: 10.3233/JAE-2012-1542

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 779-785, 2012

Authors: Lu, An | Hameyer, Kay

Article Type: Research Article

Abstract: In this paper, a sensorless control scheme using back-EMF observer for permanent magnet synchronous motor drive (PMSM) is presented. Based on a general relationship between back-EMF and rotor position, observed rotor position is calculated and corrected with position estimation error. To obtain the velocity information from the observed rotor position, the velocity observer method and state of the art direct difference method are implemented and compared with each other.

Keywords: Back-EMF, permanent magnet synchronous motor, sensorless speed control

DOI: 10.3233/JAE-2012-1543

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 787-791, 2012

Authors: Bouchareb, Ilhem | Bentounsi, Amar | Lebaroud, Abdesselam

Article Type: Research Article

Abstract: In this paper, a new power converter with redundant topology is proposed to compare the fault tolerance capability in terms of the torque density of a 6/4 conventional switched reluctance motor (SRM) and a synchronous reluctance motor (SynRM) that uses an axially laminated rotor. The simulation of the converter is achieved through an equivalent electrical circuit built into the circuit editor, CIRFLU, coupled to the finite elements model (FEM) of the machine using FLUX 2D software …package. A numerical approach by FEM allows a finer analysis of the phenomena in transient and non-linear mode. Simulations of various defects were used to compare the performance of two machines for fault-tolerant applications. The theoretical results compared with the experimental ones existing in the literature prove the effectiveness of this study. Show more

Keywords: Converter, coupled, fault tolerance, FEM, SRM, SynRM

DOI: 10.3233/JAE-2012-1544

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 793-799, 2012