著者

井上 剛志 高木 賢太郎 竹崎 勇輝 石川 昌義

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集C編 (ISSN:18848354)

巻号頁・発行日

vol.78, no.789, pp.1680-1690, 2012 (Released:2012-05-25)

参考文献数

7

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The gyroscopic exercise tool which utilizes the gyroscopic effect caused by the whirling motion of the high speed rotating body to train the hand muscle is considered. This tool utilizes the contact phenomenon between the rotor and the case. When the input motion with 3-5 Hz is added to the case, the rotor spins in thousands rpm whirling with the precession motion which is synchronous to the input case motion. Conventional studies on this tool have assumed the continuous rolling motion of the rotor to the case. This paper does not set this assumption, and investigates the dynamical modeling of this tool considering the contact/non-contact conditions and the slip between the rotor and the case. Two kinds of motions are observed in the numerical simulation, one is the uniform precession which was observed in the conventional studies and the other is the periodically reverse precession. These two motions are physically explained, and are also observed in the experiment.

著者

吉田 優太郎 林 亮 舛屋 賢 高木 賢太郎 有田 輝 田原 健二

出版者

一般社団法人 日本ロボット学会

雑誌

日本ロボット学会誌 (ISSN:02891824)

巻号頁・発行日

vol.41, no.6, pp.573-576, 2023 (Released:2023-07-27)

参考文献数

8

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A Straight Twisted Polymeric Fiber Actuator (STPFA) has attracted attention as a new rotational actuator because it is soft, lightweight, silent, and inexpensive. It can rotate when heating, and be back when cooling. However, it is difficult to improve the response, especially in the cooling phase when using natural cooling. In order to improve the response in natural cooling, antagonistical actuation is one of the effective methods. However, the diactivated-side actuator generates a disturbance-like torque when the other-side actuator is activated due to its passive torsional spring-like characteristics. In order to realize the antagonistical actuating module using a pair of rotational-type STPFA, in this paper, the models are constructed that can estimate the torque generated at both ends of an antagonistically arranged rotational STPFA from the change in heater resistance. A sensorless output torque control method is proposed for the total torque obtained as the difference between the torques at the two ends using the proposed STPFA models. The effectiveness of the proposed method is demonstrated through fundamental experiments using a prototype module.

著者

一藁 秀行 高木 賢太郎 奥村 建斗 池亀 透

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.863, pp.18-00046, 2018 (Released:2018-07-25)

参考文献数

21

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This paper proposes a novel controlled charge source circuit for synthetic admittance of piezoelectric shunt damping system. A design method for the proposed charge source circuit is also proposed. By analyzing the stability of the charge source circuit itself in consideration of the dynamics of the operational amplifier, this paper shows the conventional simple charge source circuit can be unstable because its minimum phase margin is extremely small. Moreover, we show that the minimum phase margin of the charge source circuit itself is greatly improved by the proposed method. In the case of the parameters of the experimental apparatus in this paper, the minimum phase margin is improved from less than 5 degrees to more than 75 degrees. Finally, we carry out the characterization of the developed circuit and shunt damping experiment in order to confirm the effectiveness of the proposed charge source circuit used as the synthetic admittance.

著者

加藤 潤也 藪井 将太 高木 賢太郎 井上 剛志

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.861, pp.17-00227-17-00227, 2018 (Released:2018-05-25)

参考文献数

20

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In design of rotating machines, analysis of external force is important for stable rotating operation. The various external forces such as unbalance force, seal contact force and rotor dynamic fluid force effect on the rotor system, dynamic characteristics of rotating system is changed by the external forces. The external force can vary depending on a rotor trajectory. In previous studies, a mathematical model of the dynamic characteristics had been formulated for small amplitude orbit around the equilibrium point for the rotor trajectory. However, the formulation hasn't been yet established in the rotor trajectory with large amplitude or eccentricity caused by the external forces. In this study, an experimental system using active magnetic bearing (AMB) is developed to achieve the formulation. The system can generate any arbitrary trajectory assuming various external forces and the rotor system follow the generated trajectory. The system can estimate the external force at the same time. Current flowing through coil of the AMB is controlled by a controller designed based on the frequency response to follow the arbitrary orbit. Then, the external forces are estimated from the control signal by the disturbance observer. Experiments were performed by assuming unbalance forces generated in the elastic rotor. From the results it was confirmed experimentally that high precision tracking control and estimation of external force are possible. The various rotor trajectory under the action of the external forces can be repeated by using the system, and the external force can be analyzed by the experimental data.