著者

但馬 竜介 伊藤 誠悟

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 2010 (ISSN:24243124)

巻号頁・発行日

pp._1P1-E02_1-_1P1-E02_4, 2010 (Released:2017-06-19)

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This paper describes a concept and implementation of cone-shaped scanning LIDAR for mobile robots. It makes laser lines to scan from the top of a mobile robot for covering the whole robot body and measuring the floor shape. This concept enable mobile robots to detect terrain shape with superior and constant density. In addition, it can be used for safety sensor because the laser beams cover the robot to detect upcoming obstacles or human beings. An implementation and evaluation with a cone shaped mirror are shown.

著者

伊藤 大世 寺島 修 山田 浩幸 水上 正太

出版者

一般社団法人 日本機械学会

雑誌

北陸信越支部総会・講演会 講演論文集 2019.56 (ISSN:24242772)

巻号頁・発行日

pp.K011, 2019 (Released:2019-09-25)

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The difference of the performance sounds of the electric guitar with a metal pick guard produced by the traditional craft, “Takaoka Doki”, in Toyama prefecture was investigated. Measured sounds of the open strings of the guitar with it showed that the damping times of them became shorter than those obtained with the plastic one commonly used. Further, it was also found that the sounds of 1st and 2nd strings slightly stood out and those of the other strings were slightly suppressed when the metal one was used. Therefore, the metal pick guard is effective to make a sharp, clear, and distinct sounds.

著者

石谷 清幹

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.56, no.414, 1953

著者

高橋 裕介 小池 太輝 大島 伸行

出版者

一般社団法人 日本機械学会

雑誌

年次大会

巻号頁・発行日

vol.2018, 2018

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<p>Aerodynamic heating of an inflatable reentry vehicle, TITANS, which is one of the innovative reentry technologies, was investigated using a tightly coupled approach involving computational fluid dynamics and structure analysis. A strong shock wave at the front and a wake structure behind the TITANS vehicle were clarified. It was indicated that thermochemically nonequilibrium flow appears for a case of the peak heating altitude in the trajectory of mission. A heat flux distribution due to high temperature gradient near deformed surface was uncovered. The heat flux at the capsule part of the TITANS vehicle increased, while that on the membrane decreases. This is because the shock wave formation changed by the membrane deformation. In addition, it was indicated that wrinkles on the membrane formed by the deformation causes increase in heat flux.</p>

著者

岡田 昌章 渡部 康一

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 B編 (ISSN:03875016)

巻号頁・発行日

vol.52, no.473, pp.135-143, 1986-01-25 (Released:2008-03-28)

参考文献数

40

被引用文献数

3

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工業上重要な熱物性値である各種フロン系冷媒の表面張力に関する実測情報を収集し、比較・検討することにより各県九社の実測値についてその信頼性を評価した。これらの実測値情報にもとづき、17種類のフロン系冷媒について、広い温度範囲にわたり最も信頼し得ると考えられる表面張力値を与える相関式を、核物質に共通の関数形を用いて作成した。さらに、各温度における表面張力値を、その不確かさとともに数値表としてまとめた。

著者

長谷川 一郎

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.42, no.273, 1939

著者

泉 清高 厳 鋼 辻村 健

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.2012, pp._2P1-O03_1-_2P1-O03_2, 2012

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This paper discussed the input interface of aerial hand written characters using Kinect which is the sensor device for Xbox 360. The proposed recognition algorithm of hiragana is based on simplified glyph data composed of a stroke count and a series of writing direction. The effectiveness of our approach is demonstrated by some experiments.

著者

朝日 翔太 松井 彩華 田村 哲嗣 速水 悟 井指 諒亮 古川 輝 内藤 孝昌

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

pp.20-00020, (Released:2020-10-20)

参考文献数

15

被引用文献数

1

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In this paper, we propose a method to predict the failure of factory equipment by machine learning architectures using vibration data. We design the model so that we can predict robustly the failure of the equipment in advance. We use a Gaussian Mixture Model (GMM), a machine learning architecture, to calculate abnormality value which is used for the decision whether the state of the equipment is normal or abnormal by thresholding. We also use Long Short-Term Memory Autoencoder (LSTM-AE), one of the structures of the deep learning algorithm, for feature extraction. LSTM-AE model learns both spatial and temporal patterns which are difficult to capture with conventional machine learning algorithms. We conducted the prediction experiment using vibration data obtained from actual mechanical equipment, to confirm our method can predict the failure more robust than conventional methods. From this experiment, we found that the abnormality value tended to exceed a threshold value before the actual failure, indicating that the failure can be predicted in advance by our method. Besides, when compared with conventional methods, we found that the transition of abnormality and the accuracy of failure prediction were almost the same in all cases, but we also showed that the proposed method has superiority on robustness compared to conventional methods about the transition of abnormality and the setting of the threshold.

著者

大井 秀哉 小林 卓哉 磯貝 悠美子 野々村 千里 石丸 園子

出版者

一般社団法人 日本機械学会

雑誌

計算力学講演会講演論文集 2014.27 (ISSN:24242799)

巻号頁・発行日

pp.151-152, 2014-11-22 (Released:2017-06-19)

著者

戸田 康明

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.85, no.769, pp.1365-1370, 1982-12-05 (Released:2017-06-21)

著者

山藤 和男 越山 篤 三沢 智一 奥田 紳太郎

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.59, no.564, pp.2368-2375, 1993-08-25 (Released:2008-02-26)

参考文献数

8

被引用文献数

1 2

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The authors have investigated a parallel bicycle-type mobile robot which has a controlling arm and a working arm. In the previous papers, control methods for postural stabilization and several kinds of motion and experimental results for this vehicle were reported, in which basic movements including driving, standing up and falling down as well as use of working using the working arm were shown. However, the working capability was insufficient because the former working arm was constructed of only one link. In this study, a new type of vertical two-link working arm constituting of an overarm (first link), forearm (second link) and hand (gripper)was developed. A newly devised double-clutch mechanism is installed on the joint between the overarm and the forearm. It can be switched using wire actuators made of shape memory alloy (SMA). With the use of the clutch, rotation of the forearm and the hand is realized by switching the electric current provided for the wire actuators. Gripping motion of the hand is also attained by use of another SMA wire actuator. With the three kinds of wire actuator, we developed a lightweight working arm. This paper describes mechanisms of the working arm and motion control methods. Experimental results for motion using the working arm and postural stabilization of the robot by the controlling arm are also given. It is confirmed experimentally that the inverted pendulum-type mobile robot with the working arm developed in this study shows potential for use in the new automonous land vehicle.

著者

栖原 豊太郎

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.64, no.504, pp.1-2, 1961

著者

安食 拓哉 岡 正徳 橋口 公一

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.82, no.839, pp.16-00029, 2016 (Released:2016-07-25)

参考文献数

22

被引用文献数

4 6

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Elastoplastic analysis of solid structures under cyclic loadings is increasingly required in recent years. To this end, it is necessary to adopt elastoplastic model capable of describing cyclic loading behavior and to employ stress integration algorithm that enables effective and robust calculation. The subloading surface model excluding a purely-elastic domain is capable of describing the cyclic loading behavior in addition to the monotonic loading behavior. The complete implicit stress-update algorithm by return-mapping based on the closest-point projection for the extended subloading surface model is formulated in this article. In addition, the consistent tangent modulus tensor required for the accurate calculation by the return-mapping is formulated in the inverse matrix form. They are implemented into the implicit finite element program through the user-subroutine. We simulate elastoplastic behavior of metals to assess calculation accuracy and efficiency of the proposed algorithm. Numerical experiments for cyclic loading behavior of metals are shown in order to verify the accuracy and the efficiency of the computer program based on the return-mapping and the consistent tangent modulus tensor.

著者

山本 裕也 渡辺 桂吾 永井 伊作

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 2012.50 (ISSN:24242764)

巻号頁・発行日

pp.90301-90302, 2012-02-28 (Released:2017-06-19)

著者

栖原 豊太郎

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.64, no.504, pp.1-2, 1961-01-05 (Released:2017-06-21)

著者

菊池 孝高 木綿 隆弘 河野 孝昭

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.86, no.887, pp.20-00132, 2020 (Released:2020-07-25)

参考文献数

18

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The present paper describes the performance of a micro undershot water wheel for the power generation in a snow drainageway with the Froude number of 2 to 3. In order to optimize the installation conditions of the undershot water wheel and its arc blade, the effects of blade inlet angle β and the submerged blade height hc on the performance of the undershot micro water wheel has been investigated by field test at Shiramine district in Ishikawa Prefecture. Furthermore, two-dimensional computational fluid dynamics (CFD) has been performed using ANSYS Fluent to be shown clearly the flow of inside and outside of the undershot water wheel and its power. The water wheel has a diameter of D = 600 mm and a width of W = 410 mm. In the snow drainageway, the Froude number is Fr = 2.15 to 2.42. The CFD result of the change of the maximum power coefficient CPmax with the blade inlet angle of β agrees with the experimental one qualitatively. In the case of the submerged blade height hc/D = 0.10, the blade inlet angle β has little influence on the power coefficient CP. In the case of hc/D = 0.20 and 0.29, the peak value of the maximum power coefficient is CPmax = 0.37 and 0.27 at β = 18° and 24°, respectively. The relation between the flow in the water wheel and the generation of torque has been clarified by CFD. The negative torque generates at the rotation angle of water wheel θ = 0 ~ 40° because the separated flow from the tip of blade collides against the back of the blade. The positive torque generates at θ = 45 ~ 110° to apply the drag force by the main flow. The positive torque also generates by the water flow passing through the blades for θ = 135 ~ 210°.

著者

増田 容一 石川 将人

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 2018 (ISSN:24243124)

巻号頁・発行日

pp.1P1-F15, 2018 (Released:2018-12-25)

被引用文献数

1

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In this paper, we develop a three-legged robot without a brain. This tripedal walking robot generates gait patterns adaptively and autonomously with no sensor, or controller. The key of this adaptability is to utilize a “weakness” of low-torque motors in each leg. Each motor drives leg joint and adjusts its own phase in response to a reaction force from the ground. As a result of the dynamics of body–motor–environment interaction, the weak motors sync each other.

著者

村上 敬宜 金崎 俊彦 福島 良博 田中 裕之 戸室 仁一 久保山 孝治 松栄 雅樹 伊藤 義雄 安藤 晴彦

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.75, no.749, pp.93-102, 2009-01-25 (Released:2017-06-09)

参考文献数

6

被引用文献数

4 7

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The fatigue failure analysis of SUS316L flexible hose of the hydrogen station which was demonstrated during EXPO 2005 in Nagoya was carried out. The fatigue fracture surface where hydrogen leakage was detected showed clear striations which revealed a unique evidence of hydrogen effect on the ratio of striation height and spacing. The number of striations observed on the leakage fracture surface was 270. Considering that the number of hydrogen supply to the fuel cell buses was 280, it can be concluded that the fatigue fracture process during the demonstration is completely controlled by microplasticity resulting ductile fracture contrary to the conventional concept expressed with a term of decohesion or hydrogen embrittlement. The striation data were used to make the fatigue crack growth rate equation which was applied to the life prediction and structural integrity assessment for a new hydrogen station. The fatigue crack growth data showed the evidence of a strong frequency effect of fatigue crack growth rate of SUS316L used in the hydrogen environment with 8 minutes hydrogen supply time at the hydrogen station.

著者

三田 信

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.115, no.1120, pp.182, 2012-03-05 (Released:2017-06-21)

参考文献数

1

著者

ケビンサニー 岡﨑 三郎 髙桑 脩 松永 久生 船越 裕亮 沖田 耕一

出版者

一般社団法人 日本機械学会

雑誌

M&M材料力学カンファレンス 2019 (ISSN:24242845)

巻号頁・発行日

pp.OS0319, 2019 (Released:2020-05-25)

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Tension-compression fatigue tests were conducted on non-charged and hydrogen-charged additively manufactured Ni-based superalloy 718 to investigate the effect of solute hydrogen on the fatigue strength properties of the material. The surface condition of the specimens was either as-built or mechanically-polished, aiming to clarify the effect of process-induced defects and roughness on the property. Fractographic observations using a scanning electron microscope manifested that process-induced defects existed at the fracture origin of as-built specimens, whereas such defects were not observed in the mechanically-polished specimens. However, both the fatigue life and the fatigue limit of the specimens were neither affected by surface condition nor by hydrogen. The results revealed that (1) the defects were not detrimental to the fatigue strength of the material due to its large defect-size tolerance accounted to its coarse-grained microstructure, based on comparison with previous studies conducted on forged Alloy 718, and (2) hydrogen caused no remarkable influence on both crack growth rate and crack growth threshold of the material.