International Journal of Applied Electromagnetics and Mechanics - Volume 13, issue 1-4

Authors: Ohira, Yasuhiro | Houda, Hiroshi | Sawada, Tatsuo

Article Type: Research Article

Abstract: The frequency response of a tuned liquid damper (TLD) which uses a magnetic fluid (called a "tuned magnetic fluid damper" (TMFD)) is investigated. A single-degree-of-freedom tuned mass damper (TMD) analogy is used to define the effective mass, stiffness and damping and these parameters are then estimated from experimental results. A numerical simulation is used to examine the TMFD and appropriate magnetic field conditions for effective damping are predicted. In particular, the performance of the TMFD was …improved by switching the applied magnetic field at a point near the resonant frequency of the undamped structure. Show more

DOI: 10.3233/JAE-2002-304

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 71-78, 2002

Authors: Watanabe, Ken | Ohta, Yasuhiro | Nagai, Masao | Kamada, Takayoshi

Article Type: Research Article

Abstract: The superconducting Maglev system is conceptualized as the next generation high-speed public transportation system. For practical use, it is important to improve the ride comfort particularly in high-speed running. The Maglev vehicle is composed of lightweight car bodies and bogies which are mounted with SCMs (superconducting magnets), on-board refrigerating system, etc. The vibration isolation performance is lower than in conventional railways, since the mass ratio of sprung mass to un-sprung mass in the Maglev …vehicle is lower than in the typical railway car. In this magnetically levitated system, the passive electromagnetic damping between the SCMs and ground coils is very small. Therefore, it is important to add active electromagnetic damping to the primary suspension between the SCMs and ground coils, and to adjust the secondary suspension between the car body and bogie. This paper examines lateral and rolling vibration control of the Maglev vehicle using LQ (linear quadratic) control theory. Moreover, the estimated electromagnetic damping, which interacts between the SCMs and the guideway, is also considered in the model to improve the ride comfort. Show more

DOI: 10.3233/JAE-2002-317

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 79-83, 2002

Authors: Ito, Tomoyuki | Kawamoto, Hiroyuki

Article Type: Research Article

Abstract: A stable and accurate numerical simulation technique is proposed to investigate performance of the transfer system using a biased transfer roller (BTR) in electrophotography. A one-dimensional layer-structured model was used to calculate distribution of electric field and current under air discharge. Concentration of generated ozone was also calculated. As results of calculations for a typical black and white laser printer, it was shown that (1) a transfer system using a semi-conductive BTR under constant current operation …was robust against variation in resistance of media, and (2) concentration of ozone in the BTR system was two orders lower than that in the system using a conventional corona device. Show more

DOI: 10.3233/JAE-2002-306

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 85-92, 2002

Authors: Nozawa, Naotake

Article Type: Research Article

Abstract: This paper concerns the dynamic response of an infinitely long thick plate. The plate is simply supported at the edges and subjected to initial in-plane stresses parallel and perpendicular to the edges. The plate is an orthotropic plate and rests on a viscoelastic foundation, where an impulsive line load excites it. Dynamic coefficients have been calculated and displayed graphically for several values of the initial stress parameters.

DOI: 10.3233/JAE-2002-303

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 93-97, 2002

Authors: Dharmawan, H.A. | Ali, S.A.M.

Article Type: Research Article

Abstract: Research on a switchable transformer has proven that series and parallel configurations used in the primary and secondary windings can decrease the amounts of total losses which are made up of core losses and winding losses. Both configurations are integrated through some Solid State Relays (SSRs). When utilising this transformer however, some complications arise. The main concern is timings of switching from one configuration to another, and timings of triggers which should be applied to the …SSRs. This paper proposes the use of the micro-controller 80C552 as the main control system to overcome the problems. The timings are controlled through the combination use of timer T0, T2, capture and compare interrupts. Show more

DOI: 10.3233/JAE-2002-302

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 99-106, 2002

Authors: Enge, Olaf | Maißer, Peter | Jungnickel, Uwe

Article Type: Research Article

Abstract: Based on a unified mathematical approach for modelling electromechanical systems (EMS), this paper shows a method to control dynamically the motion of an electrically driven micromirror on a nominal trajectory. For every time interval, this is done in three steps: Inverse dynamics of the mechanical subsystem, calculation of appropriate charges to produce the control forces electrically, and inverse dynamics of the electrical subsystem. The usage of an augmented PD-control law in the first step …guarantees global exponential stability of the mirror on the nominal trajectory. The second step is carried out by an optimization method of linear programming. In the third step, the voltages are computed neglecting the dynamics of the electrical subsystem. Finally, these voltages are applied at the simulation model of the micromirror. Show more

DOI: 10.3233/JAE-2002-515

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 107-112, 2002

Authors: Alessandroni, Silvio | dell'Isola, Francesco | Frezza, Fabrizio

Article Type: Research Article

Abstract: A new way of coupling electrical and mechanical waves, using piezoelectric effect, is presented here. Since the energy exchange between two systems supporting wave propagation is maximum when their evolution is governed by similar equations, hence, an optimal electro-mechanical coupling is obtained by designing an electric network which is "analog" to the mechanical structure to be controlled. In this paper, we exploit this idea to enhance the coupling, between a Kirchhoff-Love plate and one possible synthesis …of its circuital analog, as obtained by means of a set of piezoelectric actuators uniformly distributed upon the plate. It is shown how this approach allows for an optimal energy exchange between the mechanic and the electric forms independent of the modal evolution of the structure. Moreover, we show how an efficient electric dissipation of the mechanical energy can be obtained adding dissipative elements in the electric network. Show more

DOI: 10.3233/JAE-2002-488

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 113-120, 2002

Authors: Sekihara, Takanori | Oshinoya, Yasuo | Ishibashi, Kazuhisa

Article Type: Research Article

Abstract: When sheet steel travels at high speed in a processing facility, rollers are usually used as supporters. However, when rollers are used, deterioration caused by cracking is possible. The authors have proposed a magnetic levitation control system for sheet steel and confirmed the feasibility by an experiment on digital control. However, there is no horizontal restraining force in transport in the case of using only levitation control. Therefore, we proposed to install electromagnets in order to …control the horizontal position. For the basic examinations, the sheet steel plate (length 800 mm, width 600 mm, thickness 0.3 mm) was reinforced by light carbon pipes in this study. To verify the usefulness of the proposed noncontact positioning control system of sheet steel, a digital control experiment was performed on transport. As a result, good positioning control performance for the levitated steel plate was obtained. Show more

DOI: 10.3233/JAE-2002-310

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 121-128, 2002

Authors: Sase, Masanori | Torii, Susumu

Article Type: Research Article

Abstract: The authors propose the magnetic levitation control of thin steel plates using the real-time finite element analysis of the vibration. This paper describes the concept of the proposed levitation system, the finite element simulation of presuming the displacement, and the applicability from the viewpoint of calculation time.

DOI: 10.3233/JAE-2002-486

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 129-136, 2002

Authors: Yoshida, Hidehisa | Nagai, Masao

Article Type: Research Article

Abstract: When a railway vehicle passes through a curve, reducing the lateral acceleration affecting its passengers is important in order to improve the ride comfort. Tilting control by feedback, which can maintain the vehicle inclination close to a desired value, is examined in this paper; reduction of car body vibration is also anticipated with this control. Specifically, the curvature is obtained by collecting data in real time from the car body traveling through a curve, and this …information is utilized in the proposed tilting control method. The effects of the control scheme are verified by computer simulation using a dynamic model and experiment with model equipment. Show more

DOI: 10.3233/JAE-2002-516

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 137-144, 2002