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

Authors: Murai, Masanori | Tani, Junji | Qiu, Jinhao

Article Type: Research Article

Abstract: This paper describes a new type of two stage servo head arm for magnetic disk drives. Four PZT actuators were bonded to the stainless steel head arm. The PZT actuators were used for accurate follow-up of the track and also vibration control of the head arm. The PID control method was used in the design of controllers for vibration control and tracking follow-up control of the arm. The characteristics of a prototype of the servo system were measured …and its effectiveness was verified by experiment. Show more

DOI: 10.3233/JAE-2002-311

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 145-149, 2002

Authors: Murakoshi, Takao

Article Type: Research Article

Abstract: A two-axis antenna-stabilizing control device which does not need a level sensor has been developed. The control incorporates a zero-servo method which zeros two gyro outputs by rotating an antenna with both an azimuth motor and an elevation-servo motor. In experiments using a Scorsby Table, pointing errors of less than a few degrees have been confirmed.

DOI: 10.3233/JAE-2002-316

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 151-154, 2002

Authors: Mizuno, Takeshi | Aizawa, Mitsunori

Article Type: Research Article

Abstract: A magnetic bearing system using forces of repulsion between permanent magnets was developed. In the developed magnetic bearing, the radial motions of the rotor are passively supported by repulsive forces. The motion in the axial direction, which is inherently unstable, is stabilized by using the motion control of the permanent magnets for passive radial suspension with a piezoelectric actuator. The developed magnetic bearing suspended a rotor without any mechanical contact. The characteristics of the suspension system …were studied both theoretically and experimentally. Show more

DOI: 10.3233/JAE-2002-312

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 155-162, 2002

Authors: Itoh, Yoshiaki | Nagao, Tatsuaki | Ozawa, Toshifumi | Iwai, Hiroyuki

Article Type: Research Article

Abstract: In security camera, the exposure control system, called Iris meter, is widely applied to provide the optimal aperture of the lens for brightness. Sometimes, the unexpected vibration of the exposure control system is observed when the lens aperture is in the transient state of opening and closing. Such the vibration may not only lead the system status to the abnormal condition, but also play an important role in the long-term reliability of the system. The purpose …of this paper is to examine the vibration of the exposure control system in security camera. First, some experiments are conducted to observe the dynamic properties of the system at the normal and abnormal condition. Second, theoretical discussion is made to give some information on the excitation mechanism of the vibration. Show more

DOI: 10.3233/JAE-2002-309

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 163-170, 2002

Authors: Takahara, Kenji | Yamanouchi, Youichi | Kawaguchi, Hideki

Article Type: Research Article

Abstract: The purpose of the present study is to construct a system to maintain the output power of the photovoltaic power generation system (PV system) at its maximum power levels. The switch duty ratio of the DC-DC converter of the PV system and its output power are selected as the input and output values, respectively. The characteristics of the PV system, which are described by the characteristic curves, are changed according to changes in external environmental conditions, …such as atmosphere, loads and so on. In this study, the characteristic curves are considered to be approximated by quadratic functions and their gradients by linear functions. The change in the switch duty ratio is determined by the fuzzy controller, based on the characteristic curves and their gradients estimated by an adaptive algorithm. Show more

DOI: 10.3233/JAE-2002-315

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 171-180, 2002

Authors: Hirano, Keiichi | Um, Yongsu | Kano, Yoshio

Article Type: Research Article

Abstract: Nonlinear modeling ideas of a Linear Reluctance Motor (Linear RM) as an MIMO system are proposed here. Fast settling time and an interesting input trajectory are performed on Model Predictive Controlled DC motor position simulation. Prospects for the nonlinear MPC simulation and the advantages to apply the method for linear motor controller are discussed.

DOI: 10.3233/JAE-2002-514

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 181-185, 2002

Authors: Imai, Hidekazu | Tanaka, Tomomichi | Nakagawa, Toshiko

Article Type: Research Article

Abstract: In the process line of a strip belt, it is desirable to reduce contacts between rollers and steel strips to produce better quality. In addition, it is also desirable to hold the shape or to suppress vibration with as little contact as possible. This paper proposes a model apparatus for controlling vibration without any contact. It aims to use economic and compact current-sensors instead of expensive gap ones and also the controlled attractive force of electromagnets. …This paper investigates the effects for the several types of vibration control effects for the strips by digital simulations and experiments. Show more

Keywords: vibration control, steel strips, process line, current sensors, observer

DOI: 10.3233/JAE-2002-308

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 187-194, 2002

Authors: Weyand, Kurt

Article Type: Research Article

Abstract: The present state of realization, maintenance and dissemination the quantity "magnetic flux density" in SI units is discussed. Different measuring methods that are in use for the calibration of field coils and permanent or electromagnetic systems in the flux density range from the order of the Earth's magnetic field up to some Tesla are compared with respect to their uncertainties. Special attention is given to systems based on the gyromagnetic ratio of protons as a fundamental …constant. Show more

DOI: 10.3233/JAE-2002-340

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 195-202, 2002

Authors: Enokizono, Masato

Article Type: Research Article

Abstract: This paper presents a numerical modeling of vector (two-dimensional) magnetic properties considering hysteresis of silicon steel sheets. We define the magnetic reluctivity tensor newly and calculate it from the measurement data obtained by two-dimensional magnetic measurement. Our new modelings, which are "E&S Model" and "E&S2 Model", can be introduced into a finite element formulation for magnetic field analysis and can get the distribution of the magnetic field strength H-vector and the magnetic flux density …B-vector. Show more

DOI: 10.3233/JAE-2002-341

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 203-208, 2002

Authors: Saghafifar, Mahmoud | Kundu, Anjan | Nafalski, Andrew

Article Type: Research Article

Abstract: Dynamic magnetic hysteresis modelling is of crucial importance in determining the electromagnetic behaviour of magnetic cores. Among the different models of magnetic hysteresis, Preisach model is one of the more commonly applied. The dynamic Preisach model is a generalisation of the static Preisach model, and is obtained by adding the rate of change of the output variable, which makes the numerical implementation more complex. Since dynamic hysteresis models require mapping of time dependent sequences, a …feature available in some neural networks, in this paper the application of recurrent neural networks to model dynamic hysteresis was investigated. An Elman neural network was selected to test the concept. The network was trained with a set of measured dynamic data and was tested with another set of experimental data, showing acceptable accuracy. Show more

DOI: 10.3233/JAE-2002-323

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 13, no. 1-4, pp. 209-214, 2002