著者

山崎 次男 川田 良暁 石野 裕二 山田 幸男 塚崎 重多郎

出版者

公益社団法人 精密工学会

雑誌

精密工学会学術講演会講演論文集 2004年度精密工学会春季大会

巻号頁・発行日

pp.346, 2004-03-16 (Released:2005-03-01)

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指南車の紹介や復元が行われている。指南車に関する歴史的な背景や調査等を行ってきた。従来復元されている、リンク-歯車式、差動歯車式などと異なる機構で復元を試みた。遊星歯車方式と内歯車駆動とを組み合わせることによって完成することが出来た。

著者

成澤 慶宜 水野 毅 高崎 正也 石野 裕二 原 正之 山口 大介

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.17-00523-17-00523, 2018 (Released:2018-05-25)

参考文献数

17

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A basic single-degree-of-freedom magnetic suspension system consists of one floator, one electromagnet and one amplifier. For multi-degrees-of-freedom control, multiple electromagnets and multiple amplifiers are necessary, which increases the cost of total system. As a means of overcoming this problem, parallel magnetic suspension has been proposed which controls multiple floators or multi-degree-of-freedom motions with a single power amplifier. In this system, all of the suspended points move simultaneously even when a disturbance acts on one of the suspended points solely because all electromagnet's coils are connected. This paper studies the moving direction of each suspended point with respect to a step disturbance in double parallel magnetic suspension system. The analytical study shows that the response direction is determined by the system parameter that relates the response speed of each subsystem. In the slower subsystem, the suspended point moves in the same direction as the applied force while in the faster subsystem, the suspended point moves in the opposite direction. In other words, the slower subsystem has positive stiffness while the faster system has negative stiffness. To confirm this prediction, step responses are measured in the experimental apparatus.

著者

水野 毅 Asief JAVED 石野 裕二 髙﨑 正也

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.83, no.854, pp.17-00217-17-00217, 2017 (Released:2017-10-25)

参考文献数

19

被引用文献数

2

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A switching stiffness control and a modified variable stiffness control were applied to reduce vibration in the lateral directions in active magnetic suspension system with electromagnets operated in the differential mode. The magnetic suspension system using the attractive force between magnetized bodies is inherently unstable in the normal direction so that feedback control is necessary to achieve stable suspension. In contrast, it is usually stable in the lateral directions because of the edge effects in the magnetic circuits. However, damping in the lateral directions is poor so that vibration is easily induced. In this work, a switching stiffness control was applied to attenuate such vibration. The effectiveness of the switching stiffness control was confirmed experimentally. In addition, a modified control method that varies stiffness continuously was proposed to overcome problems occurring in switching. The efficacy of the modified control method was also confirmed experimentally.

著者

水野 毅 石野 裕二 髙﨑 正也

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.83, no.849, pp.16-00558-16-00558, 2017 (Released:2017-05-25)

参考文献数

6

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A new over-flow prevention valve with a trigger mechanism is designed, fabricated and studied experimentally to evaluate its performances. Loading arms are used to transfer combustible fluid such as oil between tankers and tanks. A loading arm is equipped with an over-flow prevention valve for safety. This valve stops the fluid flow when the fluid exceeds a threshold level in a tank. It must be composed of mechanical elements solely because electric components may induce combustion. Therefore, it uses a pneumatic circuit to detect the fluid level and close the valve. The fabricated valve utilizes positive pressure caused by the height difference of fluid level between the tank and the sensor probe instead of negative pressure that was used in a conventional valve. However, the positive pressure is insufficient to close the valve directly. Therefore, a trigger mechanism is introduced between a piston pushed by the positive pressure and a locking mechanism keeping the valve open. This mechanism generates sufficient force to release the lock and close the main valve from the force pushing the piston. The concept, operation principles and the pneumatic circuit design are presented. Experiments simulating actual operation are carried out with the fabricated valve. The sensor probe is inserted into the water with a constant speed by a single-axis robot instead of flowing oil into the tank. The relation between the velocity and the depth when the valve closes are studied experimentally.

著者

水野 毅 酒井 康博 髙﨑 正也 石野 裕二

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.83, no.849, pp.16-00482-16-00482, 2017 (Released:2017-05-25)

参考文献数

23

被引用文献数

2

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A wind-tunnel system for spinning body has been proposed to measure hydrodynamic forces acting on the body. In the proposed system, the body is suspended and rotated by electromagnets. The forces are measured from the control signal for suspension. In the previously fabricated apparatus, eight electromagnets were placed around a wind-tunnel. An optical displacement sensor was used to detect the three-dimensional positions of the body. Stable suspension and three-dimensional positioning of the body were achieved. However, it had several problems; the test section area was rather small and vibration was induced by flowing wind to the floator. To solve such problems, a new wind-tunnel using magnetic suspension is developed. It has two and a quarter times test section area. The position sensor is improved to operate in a differential mode in all the directions. Stable suspension and rotation of the floator are achieved. The floator is kept stably without vibration even in the face of wind. The hydrodynamic forces acting on the spinning floator are measured.

著者

石橋 尚宜 水野 毅 石野 裕二 髙﨑 正也 山口 大介 原 正之 渡邊 怜

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.83, no.849, pp.16-00404-16-00404, 2017 (Released:2017-05-25)

参考文献数

11

被引用文献数

2

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This paper treats a relay-feedback mass measurement system that uses a relay with hysteresis and feeds back the velocity of the object. The measurement system has an on-off relay with hysteresis and switches force acting on the object in relation to its velocity. Such nonlinear control induces a limit cycle. The mass of the object is determined from the period of this cycle. In previous study, the actual trajectory of the limit cycle was different in shape from the theoretical one so that the prerequisites of the estimation formula were not satisfied. The delay of the velocity sensor is a main factor of such degradation. In this paper, the effect of the delay on mass estimation is investigated experimentally and analytically. In addition, an estimating equation including this effect is derived. Experimental result supports the validity of the derived estimating equation.

著者

石野 裕二 水野 毅

出版者

自動制御連合講演会

雑誌

自動制御連合講演会講演論文集 第54回自動制御連合講演会

巻号頁・発行日

pp.323, 2011 (Released:2012-03-09)

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磁気浮上制御系の一つに,ゼロパワー磁気浮上系がある.一方,最近では太陽光発電は安価で数十~百数十Wh/m2と効率がよいものが市販され,さらに小型で大容量のコンデンサが容易に手に入るようになった.これらの技術とゼロパワー磁気浮上系を用いると,一般商用電源からの電力供給なしに,重力環境下でも十分磁気浮上が可能である.そこで太陽電池を電源としたゼロパワー磁気浮上装置の開発を行う.