researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tmag.2018.2845438

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.ymssp.2024.111319

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.jsv.2023.118191

researchmap

Publishing type：Research paper (scientific journal)  

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ASME International  

Abstract

The rotordynamic (RD) fluid force generated in fluid elements such as seals in turbomachinery affects the stability of turbomachinery and causes shaft vibrations. Various studies have been conducted to clarify the effects of seals on the stability of rotor systems. Many studies have investigated the rotor dynamics of horizontal shaft systems, considering the RD fluid force generated in the seals, and in these studies, the stability of horizontal shaft systems has been assessed via eigenvalue analysis using RD coefficients. However, few studies have analyzed vertical shaft systems. The dynamic behavior of vertical shafts differs significantly from that of horizontal shafts because the weight of the rotor does not act on the seal in a vertical shaft system. Vertical shaft systems are generally prone to instability because of the fluid film whirl, and the amplitude of the shaft whirl tends to be large. When the amplitude is large, the RD fluid force cannot be linearized around the equilibrium point using RD coefficients. Therefore, destabilization and stabilization phenomena that appear in vertical shaft systems cannot be predicted using eigenvalue analysis. Fluid-structure interaction (FSI) analysis that considers the interaction between the shaft vibration and the RD fluid force generated in seals is required to predict such phenomena. This study used FSI analysis to investigate the effects of unbalance and differential pressure on the stability of a vertical shaft system subjected to RD fluid force generated in the seal.

DOI： 10.1115/1.4064725

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tmag.2023.3291016

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Fuji Technology Press Ltd.  

Haptics applications are receiving increasing attention in entertainment, medical support systems, and various industries. Three-dimensional (3D) haptics is important to provide users real experiences. Conventional haptic devices consist of many motors and mechanical elements grounded in an environment. Therefore, they are large in size and heavy. Haptic devices using asymmetric vibrations can display illusion forces with mobile structures. However, they need additional structures (comprising actuators) to generate a 3D illusion force; however, the operational mechanism becomes complex. To solve this problem, we propose the use of a 3-degree-of-freedom (3DOF) oscillatory actuator that can generate a 3DOF vibration using only one actuator. This study describes the basic characteristics and operating verification of the 3DOF oscillatory actuator. The static thrust characteristics are quantified and analyzed using a finite element method. The dynamics are calculated based on numerical simulations using a dynamic model. The prototype’s experimental results show that the 3DOF actuator can generate 3DOF vibration.

DOI： 10.20965/jrm.2023.p1312

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.31.431

researchmap

Authorship：Last author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Last author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Last author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Last author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SAGE Publications  

Pumps are important machines used in rivers, social infrastructure, and industrial facilities. During long-term operation, journal bearings that support the pump shaft are subject to wear and peeling caused by liquids, including slurry. Wear and peeling can change the characteristics of journal bearings and cause abnormal shaft vibration. If wear and peeling progress, it can severely damage the pump. Thus, periodic maintenance and replacement are required. However, the frequency of periodic maintenance should be reduced as much as possible from a cost standpoint. Therefore, it is desirable to monitor the condition of the machine and perform maintenance only when necessary. In this study, the long-term vibration of a submerged journal bearing with slurry-containing water was monitored and recorded to identify the features that are important for condition monitoring and diagnosis and to interpret their contributions. First, an experimental test rig for a rotating shaft system was developed and long-term vibration data and changes in wear were recorded. A machine learning model (support vector machine (SVM)) was trained to predict the wear and damage conditions of the bearings, and its effectiveness was verified. In addition, two important features were selected as major contributors to the wear and peeling phenomena of journal bearings. These important features were interpreted using partial dependence (PD), Individual Conditional Expectation (ICE), and SHapley Additive exPlanations (SHAP), and the degree of contribution and characteristics of these features were clarified. Later, a reduced SVM model was trained using only these important features, and its effectiveness was clarified using another bearing’s data of wear and peeling processes.

DOI： 10.1177/14759217231184579

researchmap

Other Link： http://journals.sagepub.com/doi/full-xml/10.1177/14759217231184579

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.31.285

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.31.114

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.31.60

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.31.413

researchmap

Authorship：Last author   Publishing type：Research paper (scientific journal)  

In recent years, there has been a demand for turbomachinery with increasing speed, pressure, and compactness owing to the increasing demand for high output and efficiency. Consequently, various shaft vibration problems have become apparent. The rotor dynamic (RD) forces are one of the causes of these axial vibrations, which can lead to instability of the rotor system. To ensure the reliability of turbomachinery, the effect of RD fluid force should be analyzed at the design stage. In this study, high-precision tracking control of a complex orbit was analyzed using an experimental approach, and a highly efficient and low-dispersion estimation of the RD fluid force was achieved. The target was a parallel annular seal, and an experimental system was developed to control the rotor position using a piezo-electric actuator. Using the adaptive feedforward cancellation (AFC), we suppressed the periodic disturbance caused by rotation, whirling, and disturbances, such as noise that existed uniformly at all frequencies. Thus, a high-precision tracking control with an orbit tracking error of approximately 1 μm was achieved. The RD fluid force was estimated from the output signal of the AFC during high-precision tracking control, and the RD coefficient was calculated using spectral analysis. Consequently, a highly accurate RD fluid force estimation with reduced dispersion was achieved. In addition, a multifrequency orbit control and RD fluid force estimation method were developed to improve the efficiency of the RD force estimation, which agreed well with the results of a single-frequency orbit.

DOI： 10.1115/1.4055590

Scopus

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Camera attitude control systems for robots require a compact structure and high responsiveness. However, due to the combination structure of several actuators, the camera attitude control system is large. To address this issue, this study proposes a three-degree-of-freedom (3DOF) voice coil actuator. A single actuator is used to generate 3DOF motion, which is driven by a four-phase current. This study also describes the basic structure and operating principle of the actuator and clarifies the torque characteristics using a three-dimensional (3D) finite element method (FEM). Furthermore, the dynamic modeling and control methods are presented. The FEM and dynamic simulation results reveal that the proposed actuator can be arbitrarily driven in 3DOF.

DOI： 10.3390/s22186926

researchmap

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.30.167

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.30.185

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.30.173

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.30.203

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.30.191

researchmap

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/tee.23577

researchmap

Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/tee.23577

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/tee.23563

researchmap

Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/tee.23563

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical Engineers of Japan (IEE Japan)  

DOI： 10.1541/ieejjia.20004730

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOS Press  

Space recognition is a crucial issue for autonomous systems such as unmanned aerial vehicles, walking robots, and autonomous cars. These systems are necessary to obtain information using a camera while moving. However, reduction in recognition accuracy and system size increase has created problems. To solve these problems, we proposed the three-degree-of-freedom (DOF) actuator for image stabilization. This paper proposes a novel initial position estimation method and sensorless attitude estimation method for the three-DOF actuator to further downsize and reduce weight. The effectiveness of the proposed methods is verified by a magnetic field analysis, using a three-dimensional finite element method and numerical simulations.

DOI： 10.3233/jae-201537

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)  

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)  

researchmap

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/tee.23317

researchmap

Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/tee.23317

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.29.124

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Walter de Gruyter GmbH  

<title>Abstract</title>This article proposes a thrust equation model of two-degree-of-freedom oscillatory actuator considering its edge effect. The proposed thrust equation model clarifies that asymmetric permanent magnet flux linkage and inductance characteristics cause undesirable magnetic thrust and reluctance thrust, respectively.

DOI： 10.1515/phys-2020-0169

researchmap

Other Link： https://www.degruyter.com/document/doi/10.1515/phys-2020-0169/pdf

Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical Engineers of Japan (IEE Japan)  

DOI： 10.1541/ieejias.140.534

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Image deteriorations due to vibrations have become a problem in autonomous systems such as unmanned aerial vehicles, robots, and autonomous cars. To suppress the vibration, a camera stabilizer using a gimbal mechanism is widely used. However, the size and weight of the system increase because the conventional image stabilization systems require some actuators and links to drive in multi-axes. In order to solve these problems, we proposed a novel three-degree-of-freedom (3DOF) electromagnetic actuator for image stabilization. The actuator can be driven by only three-phase and has a simple structure and control system. This paper describes the experimental verification of the proposed actuator. The torque characteristics are clarified, and the analysis and measured torque characteristics are compared to verify the analysis validity. For verifying the dynamic performance, the frequency characteristics are measured. The effectiveness of the proposed magnetic structure and operating principle are investigated.

DOI： 10.3390/s20092485

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ECO-Vector LLC  

Background: Linear motion devices for industrial machines and robots are expected to realize their high efficiency drive and simple structure. Usually, a feed screw mechanism composed of a rotary motor and a ball-screw or slide-screw is employed. However, it has some problems such as the decrease of the drive efficiency, flexibility against external forces, noise, etc. Various linear actuators and motors have been developed utilizing the feature of a direct drive.&#x0D;
Aim: In this paper, we propose a novel linear actuator which 2 movers can be independently controlled using 3-phase and 6-phase superimposed currents for decreasing the size and weight of the system. The proposed linear actuator is driven by the operating principle of a vernier motor which is expected to achieve a high thrust force density per permanent magnet volume.&#x0D;
Methods: The operating principle and the static thrust force characteristics of the proposed linear actuator are verified by an electromagnetic field analysis using 3-D finite element method, and the back electromotive force characteristics are also analyzed. In addition, the dynamic characteristics under position feedback control are analyzed. The control system uses a vector control using PID controller, and the control input is given by the 3-phase and 6-phase superimposed currents.&#x0D;
Results: The static force characteristics were investigated. From the analyzed results, the force interference between the two movers was small. Moreover, the interference of the back electromotive force of the 3-phase and 6-phase movers were not observed. The movers could be independently driven under position feedback control using 3-phase and 6-phase superimposed currents. The dynamic characteristics analyses showed that the mover well followed a target position. From a step response, the time constant and the response of the position feedback system were investigated.&#x0D;
Conclusion: This paper presents a linear vernier actuator with two movers. The basic structure and operating principle of the actuator were described. Moreover, the static characteristics and the dynamic characteristics under position feedback control were analyzed. It was found that the movers can be independently driven.

DOI： 10.17816/transsyst20206163-79

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.28.219

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/iecon.2019.8927701

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/icems.2019.8922479

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/ldia.2019.8770992

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

DOI： 10.14243/jsaem.26.280

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tmag.2017.2706942

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/tmag.2017.2664144

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

<p>A lens-unit-swing system is composed of lens and an imaging device for image stabilizations. This system can correct an image from camera shakes over wide rotation ranges around three axes. On the other hand, this system has some problems such as an increase in size and power consumption. Therefore, three-degree-of-freedom actuators are expected to become a solution for these problems. However, it is difficult to incorporate these actuators in the system because the size is large and it has a complicated control system. In order to solve these problems, we propose a new three-degree-of-freedom electromagnetic actuator, which can be controlled by a simple control system. In this paper, the basic structure and operating principle of the actuator are described. Moreover, the modeling method of the actuator is described. In addition, the effectiveness of the actuator is verified through 3-D finite element analysis and numerical simulation.</p>

DOI： 10.14243/jsaem.25.273

CiNii Books

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Applied Electromagnetics and Mechanics  

<p>Recently, a high-quality image has been obtained by a digital camera because imaging performance was improved. On the other hand, image quality deteriorations due to the vibration has become a problem. In this paper, we propose a three-degree-of-freedom actuator for image stabilizations. The basic structure and operating principle of the actuator are described. Moreover, the dynamic performances under position feedback control are analyzed employing 3-D finite element method and the effectiveness of the actuator is verified.</p>

DOI： 10.14243/jsaem.25.137

CiNii Books

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/IROS.2016.7759369

researchmap

Other Link： https://dblp.uni-trier.de/db/conf/iros/iros2016.html#HeyaKMHG16

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Application no：特願2023-079684  Date applied：2023.5

researchmap

Application no：特願2023-043537  Date applied：2023.3

researchmap

Applicant：部矢明，井上剛志，梅川侑大

Application no：2023-043537  Date applied：2023.3

Application no：特願2018-202245  Date applied：2018.10

researchmap