International Journal of Applied Electromagnetics and Mechanics - Volume 36, issue 4

Authors: Zhang, Chi | Zhao, Guangzhou | Tseng, King Jet

Article Type: Research Article

Abstract: This paper presents a three-link direct drive robot arm for wafer handling application. This robot arm is directly driven by three permanent magnet synchronous motors which are designed with flat structures and large rated torques. The mechanical structures of the presented robot arm and the PM motors are introduced and their dynamic models are derived. The frequency responses obtained from experimental tests reveal serious coupling effect of the system. A decoupling method based on computed torque …control is proposed and the test results validate the effectiveness of this method. Robust SISO controllers are developed to control the PM motors after the decoupling. The experimental results demonstrate satisfying dynamic, settling and static performances with the proposed robust decoupling control. Show more

Keywords: Decoupling control, robust control, direct drive, robot arm, permanent magnet synchronous motor, SCARA

DOI: 10.3233/TAD-2011-1367

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 4, pp. 279-293, 2011

Authors: Gaing, Zwe-Lee | Chiang, Jui-An

Article Type: Research Article

Abstract: In this paper, using the fuzzy-inference Taguchi method with multiple performance characteristics index (MPCI), a novel systematic approach is employed to obtain the robust design of a brushless permanent-magnet (PM) hub motor with both lower torque ripple factor and higher efficiency. According to the geometric parameters of the PM motor, we select the controllable factors and their levels, such as the permanent magnet thickness in rotor, air-gap width, opening slot width and slot tooth width at …stator. The proposed method first establishes the orthogonal array (OA) that is required by the Taguchi method. Then, the multiple targets are coordinated by the fuzzy inference mechanism to obtain the better combination of the geometric parameters for achieving multiple quality targets. Finite element method (FEM) is employed as the tool for analyzing the torque ripple and performance of the PM motor, and results have indicated that the proposed method can obtain the suitable motor's geometric parameters for reducing the cogging torque and enhancing the operating efficiency. Show more

Keywords: Hub motor, cogging torque, finite element method, taguchi method, multiple performance characteristics index

DOI: 10.3233/TAD-2011-1368

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 4, pp. 295-307, 2011

Authors: Komarov, Vyacheslav V.

Article Type: Research Article

Abstract: Diverse mathematical models are used nowadays for predicting temperature patterns in dielectric materials exposed with microwaves in domestic ovens, industrial setups, experimental chambers and etc. Most of them are nonlinear and take into account the coupling of electromagnetic and thermal fields in so-called interaction zone. The most frequently utilized coupled models of microwave heating processes are considered in present paper. It is shown that in many cases formulation of the coupled electromagnetic-thermal …problem depends on different factors and peculiarities of microwave technologies realization. Show more

Keywords: Electromagnetic field, microwave processing, mathematical modeling, coupled problem, dielectric properties

DOI: 10.3233/TAD-2011-1369

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 4, pp. 309-316, 2011

Authors: Woo, Dong-Kyun | Lim, Dong-Kuk | Ali, Mohammad | Jung, Hyun-Kyo

Article Type: Research Article

Abstract: This paper presents evolution strategy (ES) assisted by Kriging metamodel to preselect the most promising solutions and reduce the number of fitness function evaluations. The role of Kriging metamodel is to predict an objective function value for a new candidate solution by exploiting information recorded during previous generations. The use of promising solutions for screening the candidate solutions makes it possible to significantly reduce the computational cost of ES. The usefulness of the proposed method is …verified by means of mathematical test cases and the optimal rotor structure design of interior permanent magnet synchronous machine. Show more

Keywords: Evolution strategy, Kriging, optimization, permanent magnet machine

DOI: 10.3233/TAD-2011-1370

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 4, pp. 317-325, 2011

Authors: Mazlan, Saiful A. | Ismail, Izwan | Zamzuri, Hairi | Abd Fatah, A. Yasser

Article Type: Research Article

Abstract: Magnetorheological (MR) fluid exhibits a perceptible change of rheological properties in reaction to external magnetic field. The MR fluids are currently enjoying renewed interest within the technical community in terms of the fundamental and applied research. MR fluids behaviour in squeeze mode is one of the areas that remain unknown as compared to valve and shear modes. Therefore, this paper presents stress-strain relationships of MR fluids under compression and tension tests. The results demonstrated that MR …fluid corresponded to the changes in compressive and tensile stresses due to the changes in magnetic field strength. The compressive stresses were found to be much higher than the tensile stresses for the same experimental parameters. The behaviour of the MR fluids were dependent on the types of the carrier fluid and magnetic field strength. Furthermore, combinations of the stress-strain curves under quasi-static compression and tension modes were matched with the curves under dynamic loading. Show more

Keywords: Magnetorheological fluids, tensile stress, compressive stress, squeeze mode

DOI: 10.3233/JAE-2011-1371

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 4, pp. 327-337, 2011

Authors: Xie, Shejuan | Takagi, Toshiyuki | Chen, Zhenmao

Article Type: Research Article

Abstract: To investigate the possibility of reconstructing the position and size of bubble flaws in metallic foam, a Neural Network approach is applied to predict the flaw profile from Direct Current Potential Drop (DCPD) signals. A feed-forward network, improved by Principal Component Analysis (PCA) is selected for the inverse analysis. Over 100 sets of DCPD signals due to flaws with different positions and sizes are calculated using a newly developed fast forward solver and are used for …the inverse analysis. Satisfactory reconstruction results are obtained for these simulated signals. Show more

Keywords: Sizing, bubble flaw, metallic foam, neural network, DCPD, NDT

DOI: 10.3233/TAD-2011-1372

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 4, pp. 339-353, 2011