著者

木原 康之 鈴木 達也 菅野 貴皓 深尾 隆則 津坂 優子 札場 勇大 佐藤 太一 横小路 泰義

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.79, no.803, pp.2362-2372, 2013 (Released:2013-07-25)

参考文献数

13

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We have already proposed the method to transfer human skill to a robot through direct teaching. By using the method, we can automatically extract human skill including sensory feedback to adapt to environmental variation. However, we have not discussed what trajectory is robust against environmental variation. In this paper, we discuss the robustness condition of robot trajectories against environmental variation and how to derive the robust trajectory. We propose a method to determine whether a trajectory is robust or not. The method considers the probability of the environment variation uses the parameter space expression of trajectory in order to derive the robustness condition. We confirm the effectiveness of the proposed method through a case study on a typical assembly task, peg-in-hole.

著者

北川 石英 奥 達明 大里 拓也 村井 祐一

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.811, pp.TEP0044-TEP0044, 2014 (Released:2014-03-25)

参考文献数

18

被引用文献数

1 1

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This paper presents the temperature and velocity measurements to clarify effects of inclination angle of a heated plate φ on natural-convection heat transfer enhancement by millimeter bubbles. In the range 0≤φ≤30˚, the heat transfer coefficient with bubble injection is much higher than that without injection, and the ratio of the heat transfer coefficient with bubble injection to that without injection (heat transfer coefficient ratio) ranges from 3.0 to 5.0. This is due to enhancement of both the transport of the warm liquid toward the downstream region and the mixing of warm liquid and cool liquid. The former results from the bubble-induced liquid entrainment, and the latter is mainly due to the increase in the liquid velocity fluctuation induced by a combination of the bubble motion and the vortex shedding from the bubble interface. Moreover, the significant bubble-induced liquid entrainment and the unsteady vortex occur near the heated wall at higher inclination angle of the heated plate. Hence, the heat transfer coefficient ratio increases with increasing inclination angle of the heated plate.

著者

新宮 正弘 江口 清 山海 嘉之

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.76, no.772, pp.3630-3639, 2010

参考文献数

24

被引用文献数

1 4

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Polio survivors with severe limb paralysis cannot move their limbs voluntarily because they have a significantly reduced number of motor neurons due to the poliovirus infection. There is a danger that their ability to control their neuromuscular system, in particular fundamental abilities such as balancing flexors and extensors in the neuromuscular system may decrease dramatically in the long-term. If such polio survivors could improve their ability to balance, it would be possible for them to use the "Robot Suit HAL" wearable movement support device. HAL anticipates its wearer's intended movements through the measurement of bioelectrical signals, and generates assistive torques to support their movements. This study proposes a biofeedback training method using visual information, with the objective of restoring motor functions using HAL. A biofeedback system that feeds-back bioelectrical signals visually was developed, and tested with a polio survivor. The polio survivor was able to adjust the balance of their muscular control through the proposed training method, and voluntary motion was recorded to a paralyzed knee using a single-joint type HAL. These results suggest that polio survivors who have been paralyzed for a long time may improve their ability to control their neuromuscular system by using the proposed training method.

著者

広瀬 茂男 福島 E. 文彦 駄本 理一郎 中本 秀一

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

著者

竹崎 友吉 東條 壽

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.156, pp.221-236, 1930

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飛行機の構成材料として今日では各國共競て金属を使用する傾向が著しくなり、金屬機の研究と云ふ事柄が、世界的趨勢と成つて來たのである。尤も夫々其國の産業状態や、發達の經路、或は異つた製造方針に依つて材料選擇の上に違ひはあるが、大體に於て既に試験の時代を過ぎ、實用の時期に入つたものと云ひ得やう。今木材と金屬に就て述ぶる前に、金屬機の發達の經路及現今各國で使用して居る金屬機に就て述べ度いと想ふ。

著者

鈴木 貴之 加藤 千幸

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.808, pp.2743-2758, 2013 (Released:2013-12-25)

参考文献数

15

被引用文献数

1 2

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Over the past two decades, many types of homogeneous models have been proposed for the numerical simulation of cavitating flows. Homogeneous models represent cavitation by the media whose density continuously varies from the value corresponding to liquid to that to gas. Recent studies have, however, revealed that the present homogenous models are unable to predict the breakdown characteristics of cavitating hydrofoils. The objective of this study is to clarify causes of such inability of homogeneous models to predict breakdown characteristics of cavitating hydrofoil accurately. Theoretical analysis shows that the present cavitation models inevitably cause kinetic energy loss through expansion and contraction of the media. To illustrate this fact, we computed cavitating flows in a venturi and around a hydrofoil (NACA0015) with a homogeneous model and investigated the computed flow field in detail. It is shown that the expansion and contraction of the media based on the homogeneous model do in fact cause kinetic energy loss and as a result, a region of low velocity appears downstream of the cavity. This results in a decrease of lift force in a partial cavitation condition, which is not observed in the corresponding measurements.

著者

藤井 澄二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.21, no.105, pp.374-377, 1955-05-25 (Released:2008-03-28)

参考文献数

4

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The paper deals with the possibility of generating sustained water-hammer by a fluttering valve which statically increases its opening with the increase of the pressure in the up-stream and which is usually expected to make a system rather stable, contrarily to the valve in the author's previous papers which decreases its opening with the increase of pressure in the up-stream. When the frequency of pressure variation in the up-stream is slightly higher than the natural frequency of the valve, the phase of the motion of the valve treated here is almost reversed relatively to the phase of pressure variation, and the amplitude of the valve is considerably large. This means that the valve can act as a negative resistance for pressure waves having frequencies slightly higher than its natural frequency, if only the damping of the valve motion is sufficiently small.

著者

藤井 澄二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.18, no.66, pp.182-184, 1952 (Released:2008-03-28)

被引用文献数

1

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When a valve, which is installed at the end of a pipe line, has a tendency to decreaseits opening with the increase of the pressure difference, a growing or sustained water-hammer will be generated in the pipe line. In this case, two series of waterhammer are possible : one has a longer period than the fundamental natural period of tae water column, while the other has a shorter period than the latter.

著者

藤井 澄二 喜山 宜志明

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.18, no.73, pp.40-43, 1952-08-20 (Released:2008-03-28)

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In the first report one of the authors mentioned that a selfinduced vibration of a fluid column can be generated in a pipeline to the end of which a fluttering valve supported by a spring is installed, and that the period of the vibration can be either longer or shorter than the natural period of the pipe according to the charasteristics of the system. In the present paper, vibrations based on the natural one of the water column are studied, and those vibrations can be step-wise waves having periods T=2n/c (n=2, 3, 4…………), which show, as a special case, a rectangular wave having a period T=4/c for n=2. For n=2 the maximum pressure is twice as high as the mean pressure, while for n>3 it increases with n. Further, step-wise waves can be generated even when the mean pressure is higher than the valve-closing pressure, if only the initial disturbance is sufficiently strong.

著者

藤井 澄二 井口 雅一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.24, no.147, pp.929-934, 1958-11-25 (Released:2008-03-28)

参考文献数

4

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The self-aligning moment at the king-pin can be transmitted to the steering wheel as the restoring moment through the powered steering system, if a bilateral servomechanism is used as its servo-unit. In this paper the influence of this restoring force on the stability of the lateral motion of an automobile is studied, making us of the root-locus method. The results show that (1) the motion may become unstable, if the restoring force is not given to the steering whel, (2) there is an optimum ratio of the restoring moment at the steering wheel to the king-pin moment, and (3) the restoring force can be given by a spring installed to the steering mechanism, but in this case the lateral motion may become unstable at high speed.

著者

藤井 澄二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.13, no.44, pp.192-201, 1947-10-30 (Released:2008-03-28)

参考文献数

21

被引用文献数

1 1

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前報告において筆者は理想的な一自由度のポンプ系のサージングを理論的に取扱い,これを水管系の弛張振動として説明した.しかし實在するポンプ系については,必ず二自由度以上の系として取扱わねばならないので,本論文においては多自由度の振動系の安定性および弛張振動の概念を導入して,直列および並列の管系の安定問題を述べた.これによつて從來一貫した説明を與えることができなかつた單獨の性能と使用時とのポンプのサージングの差異・管系の他の部分の特性のサージングにおよぼす影響・空所發生の影響・ポンプの並列運轉時の安定性の問題等に關して理論的に一貫した基準を與えた.

著者

藤井 澄二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.14, no.48-3, pp.12-17, 1948-09-15 (Released:2008-03-28)

被引用文献数

1

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筆者は第1報および第2報において有限自由度のポンプ系の作働の安定性に關する一般的理論を述べたが,本報告においてはさらに實用上重要な直列および並列2自由度系について主として位相空間を利用した詳しい取扱い方を示した.Van der Polが自動振動の解析に用いた位相平面における等傾斜線法は多自由度の振動系には適用し得ないが,本報告においては特別な力連成のある2自由度振動系の振動状態が位相空間を利用して容易に直觀的に圖式的に追跡せられ,これを利用して給水管路の特性が與えられた場合のサージングの形態,複列ポンプの性能の跳躍,特性の多價性等を調べ得ることを示した.これらの結果を利用すれぱ,2自由度ポンプ系の異常運轉を防止すべき管路およびポンプの特性の選擇,結合の方法等が理論的に知られる.

著者

藤井 澄二 柴田 碧 重田 達也

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.22, no.119, pp.489-491, 1956-07-25 (Released:2008-03-28)

参考文献数

1

被引用文献数

1

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By a series of experiments on a model of an automobile propeller shaft, considerably strong whirling phenomena are found at 1/2, 1/4, 1/6, 1/8, …… of the ordinary critical speed. Calculations also show that the friction at the universal joints gives exciting forces of frequencies 2, 4, 6, 8, …… times as large as the rotating speed of the shaft, and therefore, it can be the cause of such vibrations.

著者

藤井 澄二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.13, no.44, pp.184-191, 1947-10-30 (Released:2008-03-28)

参考文献数

28

被引用文献数

3 5

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遠心式ポンブの不安定現象,すなわちサージングは,古くから知られた現象ではあるが,今日に至るもなおその機構が定性的にも況して定量的にも明らかにされておらず,したがつて,その對策も理諭的に一貫した方法でなく,經驗的にその場しのぎの處置が採られているに過ぎない.しかし現象は明らかに周期的であるから,當然振動學的立場からこれを研究すべきものであろう.筆者は從來のサージングの説明においては問題とされなかつたポンプおよび管系の負流量に對する特性および管系の慣性を導入することによつてポンプを含む系の力學的安定性および振動を論じた.この結果によればサージングは平衡點近傍の力學的不安定性に基ずく一種のRelaxation Oscillationとして説明せられ,その周期が囘轉數に關係のないこと,高調波または周期的衝撃を含むことその他種々のサージングの附帶的性質に對して一貫した解釋ができる.

著者

藤井 澄二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.22, no.119, pp.492-496, 1956-07-25 (Released:2008-03-28)

参考文献数

2

被引用文献数

3

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In some tests of automobiles it is found that some cars show stronger understeering tendency than expected from their tyre characteritics. The main cause of this effect is considered to be the flexibility of their steering systems. According to the analysis in this paper the apparent cornering power of a front wheel is expressed as EKf, where Kf is the actual cornering power of the wheel and E is a constant which is positive and smaller than the unity. This E depends on the conering power, self-aligning moment, caster angle and the flexibility of the steering system, being E=1 for a rigid steering system. Thus, the apparent cornering power of the front wheels decreases, if the steering system is flexible, and this apparent decrease in the cornering power increases the understeering tendency and the directional stability of the car.

著者

藤井 澄二 吉本 堅一 小林 文彦

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.40, no.340, pp.3329-3334, 1974-12-25 (Released:2008-03-28)

参考文献数

3

著者

藤井 澄二 吉本 堅一 小林 文彦

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.41, no.343, pp.806-812, 1975-03-25 (Released:2008-03-28)

参考文献数

2

著者

藤井 澄二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.14, no.48-3, pp.17-25, 1948-09-15 (Released:2008-03-28)

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筆者は既報においてタンクを含む管路を有し,振動論的に有限自由度の系とみなし得るようなポンプ系のサージングその他の不安定現象の發生機構および形態について詳しい理論的考察を行つた.しかしながら,ポンプの場合でもタンクを含まない長い管路中にサージングが發生する場合,あるいは普通送風機を使用する場合のごとくタンクを有せずただ管路のみで使用する場合にあつてはこれを有限自由度の系として分割して議論することは困難であり,また,そうしては現象の眞相を見失うおそれがある.それで本報告においては,これらの系を連續體として議論を行い,連續體としての安定性の判定法,矩形波の發生その他の特徴的な性質を示した.

著者

藤井 澄二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.22, no.115, pp.178-181, 1956-03-25 (Released:2008-03-28)

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A rotating shaft which is driven through an universal joint such as the propeller shaft of an automobile sometimes shows bad vibrations at lower speeds than its ordinary critical speed. This report deals with the resonance phenomenon due to the angular velocity variation caused by the universal joint. This angular velocity variation occurs two times during one revolution of the shaft and theoretically gives an exciting force with the frequency three times as high as the rotating speed. Thus, when the shaft is driven at one third of the ordinary critical speed, the frequency of the exciting force caused by the angular velocity variation coincides with the ordinary critica1 speed and the natural frequency of the shaft, causing resonance vibration. This phenomenon is also confirmed by model tests.

著者

中村 和雄

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会誌

巻号頁・発行日

vol.62, no.486, 1959