著者

植田 亮平 垣内 洋平 野沢 峻一 岡田 慧 稲葉 雅幸

出版者

一般社団法人 日本機械学会

雑誌

ロボティクス・メカトロニクス講演会講演概要集

巻号頁・発行日

vol.2011, pp._2P2-J04_1-_2P2-J04_4, 2011

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In this paper, integration of local error recovery by visual-feedback and task-level error recovery system is described. In order to build an integrated robot system which utilizes first-order logic representation at the top-level, implementing error recovery in task-level and motion-level is important. In this paper, we focus on motion-level error recovery. Motion-level error is resolved by visual-feedback and motion planner module. In proposed system, top-level task executive does not know about it. Key features of the system are: (1) local error recovery by portable visual-feedback. (2) to utilize symbol to indicate goals of motion controller rather than to use literal pose representation and background updating of the properties of symbols (3) object tracking based-on color-range sensor using particle filter method.

著者

和田 憲造 藤本 康之 早野 延男 埴谷 和宏

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:03875024)

巻号頁・発行日

vol.56, no.524, pp.935-940, 1990-04-25 (Released:2008-02-21)

参考文献数

4

被引用文献数

3

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The screw feeder is extensively used as a feeder of granular materials. Until now, a few reports regarding the fundamental characteristics of the screw feeder, for example, the required power and the quantity of discharge from the feeder, have been published. However there are almost no reports on the dynamic characteristics and the transportation mechanism. In this paper, the transporting state and the transportation mechanism of granular materials inside the screw feeder are investigated. First, the effects of the rotating speed of the screw shaft and the pressure of granular materials inside a feed hopper on the required power and quantity of discharge are examined. Secondly, the transporting state of granular materials inside the screw feeder is investigated. Then the transportation mechanism is discussed by analyzing the motion of a tracer inserted into the screw feeder and by using a velocity diagram.

著者

黒島 亮 大高 武士 門 久義

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 (ISSN:21879761)

巻号頁・発行日

vol.80, no.819, pp.FE0318, 2014 (Released:2014-11-25)

参考文献数

21

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Recently, the micro-bubble technologies are applied in a wide field, and grow to the field close to the human lives. Though many methods of micro-bubble generation have been proposed, pressure loss of a venturi tube is less than among others. The studies on micro-bubble generation with venturi tube have ever seen, but the generation mechanism of a micro-bubble is not fully evident. The purpose of this paper is to make the micro-bubble generation mechanism experimentally clear. In conclusion, by inspecting the images of high-speed camera, the water jet occurs on the trailing edge of a bubble when its leading edge arrives at the throat inlet and divides it into two parts in the throat section. Then, passing through the diffuser, outer shapes of the two parts become unstable and break down into micro-bubbles. It is clear that the mechanical conditions of this occurrence are based on the accelerations at a nozzle and a diffuser. Then, the generated bubble size is distributed around a peak of about 200µm.

著者

金子 暁子 野村 康通 高木 周 松本 洋一郎 阿部 豊

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B編 (ISSN:18848346)

巻号頁・発行日

vol.78, no.786, pp.207-217, 2012 (Released:2012-02-25)

参考文献数

14

被引用文献数

8 19

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Microbubble has distinguished characteristics of large surface area to unit volume and small buoyancy. Recently microbubble generators with low energy and high performance are required to wide applications. In the present study, we propose one new effective technique to generate tiny bubbles with less than 200μm diameter utilizing a venturi tube under high void fraction condition. The objective of the present study is to elucidate the mechanism of bubble breakup phenomena in the venturi tube and to clarify the effects of parameters which are necessary to realize an optimum system experimentally. Under low velocity condition, bubbles which were observed with a high speed camera parted gradually in a wide region. On the contrary under high velocity condition, bubbles expanded after passing through the throat and shrank rapidly. Since the speed of sound in gas-liquid system is extremely lower than that of single-phase flow, the bubble breakup phenomenon in the venturi tube is explained as the supersonic flow in a Laval nozzle. With rapid pressure recovery in diverging area, expanding bubbles collapse violently. The tiny bubbles are generated due to the surface instability of shrinking bubbles.

著者

大西 熙 室巻 孝郎 須田 敦 川田 昌克 鈴木 立人

出版者

一般社団法人 日本機械学会

雑誌

シンポジウム: スポーツ・アンド・ヒューマン・ダイナミクス講演論文集

巻号頁・発行日

vol.2017, pp.A-13, 2017

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<p>Elderly people and persons with disabilities are likey to be obstructed activities in daily life by deteriorating of sit-to-stand ability. The population of elderly people are increasing rapidly in Japan, and the support of sit-to-stand is hard work for caregivers, who are likely suffering back pain. The purpose of this study is to develop a sit-to-stand assist chair, which assists sit-to-stand movement by lifting a seat. In this report, we focus on the trajectory of a buttock in sit-to-stand, and report results of experiments on three foot height conditions. The buttock's trajectories had a S shape on the high foot height, which was the hardest condition, and was changed to an arc shape on the low foot height, which was the easiest in this study. In the case that the buttock's trajectory gets close to the arc shape, the hardness of the standing motion might be reduced. The velocity of buttock movement varies with the person's height.</p>

出版者

一般社団法人 日本機械学会

雑誌

機械學會誌

巻号頁・発行日

vol.33, no.163, pp.397-398, 1930

著者

村瀬 英一 森上 修 橋本 英樹 松崎 伊生

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B編 (ISSN:18848346)

巻号頁・発行日

vol.79, no.805, pp.1839-1847, 2013 (Released:2013-09-25)

参考文献数

9

被引用文献数

1

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Spark ignition of premixed gases was experimentally studied. Minimum ignition energy and initial burning velocity, which is a burning velocity at an initial stage of flame propagation, were measured and their dependences on equivalence ratio were discussed. Minimum ignition energy takes a minimum value when equivalence ratio is around 0.9 for methane/air mixtures, and around 1.5 for n-butane/air mixtures, which corresponds with the study of Lewis and von Elbe. A shadowgraph technique was used to observe the growth of the flame kernels. A burning velocity was measured from the images of the flame kernel, and initial burning velocity was defined as a burning velocity at the moment when the equivalent radius of the flame kernel is approximately 3.0mm. Initial burning velocity takes a maximum value when equivalence ratio is around 0.9 for methane/air mixtures, and around 1.5 for n-butane/air mixtures, while laminar burning velocity of well-grown flame takes a maximum value when equivalence ratio is around 1.1 for both mixtures as known well. This is caused by the curvature of flame surface at the initial stage. It is suggested that the equivalence-ratio dependence of minimum ignition energy is derived from that of initial burning velocity.

著者

川井田 康礼 中浦 茂樹 大畠 龍介 三平 満司

出版者

一般社団法人 日本機械学会

雑誌

「運動と振動の制御」シンポジウム講演論文集 2003.8 (ISSN:24243000)

巻号頁・発行日

pp.540-545, 2003-10-30 (Released:2017-06-19)

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Devil stick is a kind of juggling as to control a floating stick (the center stick) by hitting or pushing with other sticks (the hand sticks). Various stick motions are performed by jugglers and some of them are studied as control problem. The purpose of this paper is to rotate the center stick by only pushing with one hand stick. In other word, control objective is to maintain the position and the angular velocity of the center stick. The control strategy in this paper is as follows. To begin with, some states are controlled by output zeroing control. The output function is derived from observing the motion of good jugglers. But there are two problems in this strategy. First, since the attitude angle of the center stick is in unobservable subspace, the angular velocity can't be controlled. Secondly, the direction of the input force isn't considered. For the first problem, by solving equations of the zero dynamics, it turns out that it is possible to stabilize the angular velocity by changing the contact point of the center stick and the hand stick. For the second one, the analytical result shows that the required force depends on the angular velocity. Some numerical simulations show the usefulness of the proposed strategy.

著者

前田 弘文

出版者

一般社団法人 日本機械学会

雑誌

中国四国支部総会・講演会 講演論文集

巻号頁・発行日

vol.2012, pp.91801-91802, 2012

著者

須藤 誠一 菅 康彦 矢野 哲也 露木 浩二

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 B編 (ISSN:03875016)

巻号頁・発行日

vol.73, no.736, pp.2440-2449, 2007-12-25 (Released:2011-03-03)

参考文献数

22

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The swimming behavior of small aquatic insects was analyzed by a digital high speed camera system. The test aquatic insects were some kinds of water beetles. It was found that the average thrust force of water beetles arises from the drag difference between the power stroke and the recovery stroke in beating movement of their hindlegs. A swimming mechanism based on the kinematic analysis of water beetle swimming was designed and produced. A swimming mechanism was composed of polystyrene foam resin body, permanent magnet, and polyethyleneterephthalate film fin. A swimming mechanism was driven by the magnetic torque acting on the permanent magnet in the alternating magnetic field. Locomotion characteristics of a swimming mechanism were studied. It was found that the swimming velocity of the mechanism depends on the frequency of alternating magnetic field. The flow field around a swimming mechanism was visualized by slow shutter speed photograph. Experimental data are useful to design of micro swimming robot.

著者

バチスタ レアンドロ 酒井 康徳 朱 彊 吉岡 勇人

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会関東支部総会講演会講演論文集

巻号頁・発行日

vol.2016, pp._OS0601-1_-_OS0601-2_, 2016

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Silicon carbide (SiC) is a promising wide-bandgap semiconductor for future power electronics and system applications. However, high-efficient and ultra-precise dicing of SiC remains a challenge due to its extremely high hardness and brittleness. Investigation of the influence of laser processing parameters on cut quality of laser diced SiC wafer can improve efficiency and precision. In this work, 4H-SiC wafers were processed with multi-passes of a CO_2 continuous laser source. The influence of the laser power and scanning speed on the cut quality was evaluated. The experimental results showed that it was possible to obtain a smooth surface, with average arithmetic roughness as small as 0.56μm at effective speed as fast as 1.25mm/s.

著者

滝 史郎 小川 勇治

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 B編 (ISSN:03875016)

巻号頁・発行日

vol.55, no.516, pp.2508-2516, 1989-08-25 (Released:2008-03-28)

参考文献数

10

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Small scale experiments of unconfined fuel vapor cloud explosions are carried out for various masses of fuel (2.9-25.2 g of iso-butane), and compared with the results obtained by the numerical analysis based o the spherically expanding piston model, where the volume of the piston is expressed by a simple function of time. A self-consistent scaling law of the unconfined fuel vapor cloud explosion is found. The size and the duration of the fireball, and the peak overpressure generated by the explosion of M kg of hydrocarbon fuels, are approximated as follows, although the dispersions in experiments are large. The maximum diameter of the fireball Dmax≒5.5 M1/3 [m]. The duration of the fireball tb≒1.6 M1/6 [s] ; and the peak overpressure of the blast Δpmax≒1.6×103 M2/3r-1 [Pa], or Δpmax/p0≒5.7×10-3M1/3(r/r*)-1, where p0 is the initial pressure and r/r* is the so-called scaled distance. These relations are in good agreement not only with the present experiments but also with the existing experiments for both larger and smaller fuel vapor cloud explosions.

著者

出村 公成 舘 信博 前川 徹弥 上野 玉樹

出版者

一般社団法人 日本機械学会

雑誌

ロボティクス・メカトロニクス講演会講演概要集

巻号頁・発行日

vol.2001, 2001

被引用文献数

1

著者

謝 毅源 細井 厚志 巨 陽

出版者

一般社団法人 日本機械学会

雑誌

東海支部総会講演会講演論文集

巻号頁・発行日

vol.2014, pp._109-1_-_109-2_, 2014

著者

谷本 隆一 朝倉 孝征 今井 守之 鶴見 康昭 安田 仁彦

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:03875024)

巻号頁・発行日

vol.69, no.686, pp.2550-2555, 2003

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In recent years one-box-cars are very popular in the market. So their interior noise level is required to be the same as that of passenger cars. To find an effective way to reduce the noise level, we studied why the noise level is high in a one-box-car as compared with a passenger car. We found that, because the diesel engine is placed under the front passenger seat, only narrow space is allowed between the engine and the engine cover, and this narrow space amplifies the noise. We confirmed by numerical simulation that this conclusion is appropriate. Based on the conclusion, we proposed to set up a silencer to lower the noise level, and found that it works effectively.

著者

菅原 朝吉

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会誌 (ISSN:24242675)

巻号頁・発行日

vol.55, no.404, pp.587-591, 1952-09-05 (Released:2017-06-21)

著者

池田 邦彦

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会誌 (ISSN:00214728)

巻号頁・発行日

vol.95, no.884, pp.639-640, 1992

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会関東支部総会講演会講演論文集

巻号頁・発行日

vol.2004, 2004

著者

郷原 信郎

出版者

一般社団法人 日本機械学会

雑誌

交通・物流部門大会講演論文集

巻号頁・発行日

vol.2006, pp.1-4, 2006

著者

宮崎 浩

出版者

一般社団法人 日本機械学会

雑誌

バイオエンジニアリング講演会講演論文集

巻号頁・発行日

vol.2006, pp.270-271, 2007