International Journal of Applied Electromagnetics and Mechanics - Volume 49, issue 1

Authors: Psuj, Grzegorz

Article Type: Research Article

Abstract: In this paper, a multiple signals features data fusion approach was performed in order to increase the reliability of assessment of the damage state of the non-oriented electrical steel elements. The signals obtained by a transducer with two sensitivity axes operating under rotating AC field for samples cut out from the steel sheet at three different angles were utilized to create database. Several signals features were considered in the process of definition of feature vector corresponding to the damage stage. Next, the database was transformed in order to abstract the information content. Finally, the function combining transformed multiple parameters was …defined allowing the damage stage assessment. Show more

Keywords: Data fusion, non-destructive testing, stress evaluation, rotating flux, vector magnetic flux

DOI: 10.3233/JAE-152003

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 49, no. 1, pp. 1-7, 2015

Authors: Chen, Xing | Hu, Jibin | Peng, Zengxiong | Chen, Kai

Article Type: Research Article

Abstract: Permanent magnet synchronous motor is an electromechanical coupled system. Electromagnetic field can result in change of the dynamic behaviors of the PMSM's rotor system. Here, changes to the electromagnetic torque excitation caused by the torsional displacement are considered using electromechanical coupled dynamic equations for the rotor. Steady state solutions and their stability are determined. Effects of inner power factor angle, pole pairs, saturation coefficient and torsional stiffness of shaft are investigated. Also, numerical integration is used to validate and carry out perturbation results. Based on the results, amplitude jump and bifurcation instability phenomenon can be avoided through reasonable control of …permanent magnet synchronous motors, electromagnetic and mechanical parameters design and consequently control the torsional vibration of PMSM's rotor system. Show more

Keywords: Electromechanical coupling, PMSM, torsional vibration, multiple scales method, stability

DOI: 10.3233/JAE-140192

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 49, no. 1, pp. 9-21, 2015

Authors: Alam, T. | Faruque, M.R.I. | Islam, M.T. | Samsuzzaman, M.

Article Type: Research Article

Abstract: A new dual elliptical patch antenna is proposed for wideband wireless application. The proposed antenna achieved wideband using internal and external parasitic radiators. The microstrip transmission line fed antenna is consisted of two elliptical radiating patches with two external annular parasitic elements and a partial ground plane. The proposed antenna is printed on epoxy resin reinforced woven glass dielectric material. The antenna structure is planar, and its design is simple and easy to fabricate. Experimental result shows that the designed antenna has achieved an impedance bandwidth of 7.28 GHz (VSWR ≤ 2) from 5.72 GHz to 13.0 GHz. Moreover, …the antenna shows good radiation efficiency with accacptable radiation patterns within the operating frequency band. Show more

Keywords: Antenna, composite material, elliptical patch, parasitic patch, wideband

DOI: 10.3233/JAE-140199

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 49, no. 1, pp. 23-29, 2015

Authors: Cheng, Shih-Chieh | Lee, Kun-Chou

Article Type: Research Article

Abstract: In this paper, the antenna mode switch technique is applied to Capon DOA (direction of arrival) estimation of signal sources. The Capon method is a well-known DOA estimation algorithm. However, it often needs a large antenna array to achieve good resolution so that the cost and computation efforts are increased. To achieve good resolution without increasing the number of array elements, our antenna mode switch technique is added to Capon DOA computation. The antenna mode switch technique is a special antenna pattern which reduces the interference from spatial region not being scanned. Such a special antenna pattern can be experimentally …implemented. Numerical simulation results show that using our antenna mode switch in Capon DOA computation can significantly improve the resolution. It can be applied to small portable devices of modern wireless communication. Show more

Keywords: Direction of arrival, antenna mode switch, antenna pattern

DOI: 10.3233/JAE-150002

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 49, no. 1, pp. 31-39, 2015

Authors: Wei, Yang

Article Type: Research Article

Abstract: The overall electromagnetic (EM) scattering from a composite problem involving ship and sea is divided into two parts. For the scattering from the extra-large scale rough sea surface, it can be summed by the masses of sub-facets to avoid the huge computation complexity of sea surface global modelling. For the difference field scattering from the large scale three-dimensional (3D) ship and its underlying sea surface, the physical optics and shooting bouncing ray method are combined to rapidly compute their scatterings. Furthermore, the image theory and its some modifications are proposed to account for the EM interactions between ship and sea …surface in order to avoid modeling the nearly infinite sea surface. Only the ship needs to be thus modeled and simulated in this paper. Therefore, the proposed method can achieve a good accuracy with minimal computation resources for the composite scattering problem. Show more

Keywords: Composite scattering, ray tracing, image theory, sub-facet

DOI: 10.3233/JAE-150010

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 49, no. 1, pp. 41-50, 2015

Authors: Bissal, Ara | Magnusson, Jesper | Salinas, Ener | Engdahl, Göran

Article Type: Research Article

Abstract: In this paper, a multi-physics computational tool has been developed to accurately model and build high performance ultra-fast actuators. The research methodology is based on a finite element method model coupled with a circuit model. Electromagnetic, thermal, mechanical, and algebraic equations are implemented in Comsol Multiphysics and verified with laboratory experiments of a built prototype. A simplified model is preferred as long as its underlying assumptions hold. However, in the presence of large current and force densities, nonlinearities such as deformations may occur. Such phenomena can only be captured by the use of the …developed comprehensive multi-physics simulation model. Although this model is computationally demanding, it was shown to have an accuracy of at least 95% when compared with experiments. Show more

Keywords: Actuators, magnetic fields, mechanical factors, multiphysics, thermal factors

DOI: 10.3233/JAE-140176

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 49, no. 1, pp. 51-59, 2015

Authors: Li, Jianshuo | Xiong, Qingyu | Wang, Kai | Liang, Shan | Gao, Min

Article Type: Research Article

Abstract: Microwave heating has been widely used for its advantage of volumetric heating. For the material exposed by two input sources, due to microwave superposition property, different phase between the input sources can generate different power distribution. To achieve a uniform temperature rising process, a sliding mode neural network combined with Cuckoo Search algorithm is constructed. By regarding the power dissipation at each sampling point as an independent actuator, a sliding mode neural network control method is used to get the suitable inputs for those sampling points under uncertain process parameters. As the constraint that only three inputs variables, which are …two input powers and the phase difference between the two sources, can be controlled, Cuckoo Search is used to get the best fit values to approximate the calculated inputs at those sampling points. Tap water and White Pudding are chosen as the heating material to show the correctness and the feasibility of this algorithm, and a uniform temperature rising process can be obtained. Compared with genetic algorithm, Cuckoo Search uses less time and has a better tracking result. The algorithm is also verified in the test of microwave source output powers randomly jumping around 100 ± 40% of the calculated values, sampling temperature with the error of -0.3 ∼ 0.3 K, long sampling period of 4 seconds, and uniform temperature rising processes can be also achieved. The average temperature of those sampling points can well follow the reference trajectory. Show more

Keywords: Power and phase control, sliding mode control, neural network, cuckoo search

DOI: 10.3233/JAE-140204

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 49, no. 1, pp. 61-77, 2015

Authors: Xu, Guanghui | Chen, Xing | Zheng, Zhi | Huang, Kama

Article Type: Research Article

Abstract: A hybrid full-wave electromagnetic (EM) field-circuit simulation method, which aims at accurately analyzing microwave circuits, is proposed. This method adopts the finite-difference time-domain (FDTD) algorithm for the EM simulation, the sophisticated equivalent models in a general circuit simulator SPICE for the circuit simulation, and hybridizes the FDTD and SPICE by using the equivalent current source (ECS) approach. Moreover, three techniques, which map a lumped circuit into FDTD cells as a wire, surface or volume structure respectively, are thoroughly studied. The formulae of the ECS with these three techniques are derived and introduced in detail, and their influences on the simulation …accuracy are analyzed. The proposed method is applied to two sample circuits, a microstrip line and a frequency selective surface (FSS), both of which are loaded with diode pairs. The simulation results are compared with the measurement ones, and good agreement is observed, indicating the accuracy and versatility of the method. Show more

Keywords: Finite-difference time-domain, SPICE, hybrid field-circuit simulation, equivalent current source

DOI: 10.3233/JAE-150008

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 49, no. 1, pp. 79-90, 2015

Authors: Tu, Xiao | Zhou, Rougang | Zhou, Yunfei | Cheng, Xin | Chien, Chou Jay Tsai

Article Type: Research Article

Abstract: Mover position initialization is the prerequisite to realize the precision motion control of magnetically levitated planar actuators (MLPAs), while its basis is the initial phase positioning. In this paper, an estimation algorithm was proposed to position the mover's geometric center as well as the rolling angle in motionless MLPAs. The mechanism was that: based on the linear Hall sensors distributed at different points in the MLPA mover, the magnetic flux density at motionless state was measured, and then the first-order harmonic model of magnetic flux density distribution above the magnet array was used to solve the magnetic field phase and …rolling angle at the MLPA's geometric center. Moreover, the positioning precision was improved by adding a redundant sensor and via rational arrangement of sensors, which ensured that data would not be collected at the magnetic field peaks. The experiments indicate that after addition of one redundant sensor, the maximum errors in phase positioning and rolling positioning were both reduced. Show more

Keywords: Initial phase, rolling angle, magnetically levitated planar actuators, hall sensors

DOI: 10.3233/JAE-150016

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 49, no. 1, pp. 91-104, 2015

Authors: Qureshi, Ehtesham Mustafa | Shen, Xing | Chang, Lulu

Article Type: Research Article

Abstract: Synchronized switch damping (SSD) techniques using piezoelectric materials have been used by different researchers for many years for the structure vibration control. In these techniques, a piezoelectric patch is bonded on or embedded into the vibrating structure and connected to or disconnected from a network of electrical components through an electronic switch, which is controlled by a digital signal processor (DSP), in synchronous with the structure motion. Recently, Self-powered SSD techniques have emerged in which the DSP is replaced by a low pass filter, thus making the whole system self-powered. The control performance of the previously used Self-powered SSD techniques …heavily relied on the electrical quality factor of the shunt circuit, thus limiting their control performance as the electrical quality factor could not be increased beyond certain limit. However, in order to bypass the influence of the electrical quality factor on the control performance, a new Self-powered SSD technique has been proposed in this paper in which the inductance in the previous Self-powered SSD techniques has been replaced with a negative capacitance thus making the whole circuit capacitive without resonance. However, it is found that the voltage on the piezoelectric patch can still be inverted. In order to access the control performance of the proposed technique in comparison with the previous Self-powered SSD techniques, experiments are performed on a cantilever beam subjected to both single mode and multimode excitations. Keeping the value of negative capacitance slightly greater than the inherent capacitance of the piezoelectric patch gave the optimum damping performance. Experiments results confirmed the effectiveness of the proposed technique as compared to the previous SSD techniques. Show more

Keywords: Damping, piezoelectric, shunt, switch, self-powered

DOI: 10.3233/JAE-150017

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 49, no. 1, pp. 105-121, 2015