著者
松本 茂樹 吉田 勝俊
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 2015.14 (ISSN:24243000)
巻号頁・発行日
pp.360-365, 2015-06-22 (Released:2017-06-19)

In this study, we conduct experiments of human balancing task and present a stochastic dynamic model of the human balancing task. The parameters of the stochastic dynamic model are identified using particle swarm optimizers. Tn order to examine stochastic behavior of the human balancing, we experimentally estimate probability density function of the state quantities. The experimental result implies that the behavior of the human balance seems to be fat-tailed distribution. This experimental observation was reproduced by the model that has additive and multiplicative white Gaussian noise. This work has implications for designing human-like motions of artificial agents such as human-like partner robots.
著者
近江 宗一 井口 学
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.47, no.418, pp.993-1001, 1981-06-25 (Released:2008-03-28)
参考文献数
26
被引用文献数
2 1

前報における円管内振動流れの速度分布や管摩擦係数に関する実験結果によれば, 振動流れの乱れ生成機構は定常流れのそれと類似している. 本報告では振動流れの乱れ生成領域は定常流れの場合と同じであるとして, 管内にこの領域が完成されたときのレイノルズ数を臨界値としてこれを評価する式を導き, 計算値が測定値とよく一致することを示すとともにバースト現象が起こる臨界周期と定常乱流の平均バースト周期との関係を求めた.
著者
和田 明浩 早稲田 一嘉
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.2015, pp._J2010102--_J2010102-, 2015

Web-based simulation software for introductory physics course was developed using HTML5 technology. THML5, which is the latest version of HTML standard, include graphical extension called "CANVAS". By using CANVAS elements we can draw graphics via scripting in JavaScript, so dynamic animation of physical phenomena can be illustrated on a local PC as well as a smart-phone without installation of the software. In this study, we developed a series of software for physics education, for example parabolic motion, harmonic motion and oscillation. In order to confirm the effectiveness of the software, access analysis of the website and questionnaires to 1th-year students at our college were conducted.
著者
八瀬 快人 佐々木 大輔 門脇 惇 安原 拓海
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.20-00173, (Released:2021-05-14)
参考文献数
20
被引用文献数
2

Kyphosis causes decline in respiratory and circulatory functions owing to compresses of internal organs. The purpose of this study is to develop a posture keep assist device. The device is constructed with multiple resin components and McKibben type artificial rubber muscle. This device at initial state has a flexibility because the resin components are separated. On the other hand, the resin component can be connected by pressurized artificial muscle. The shape of device in which all resin components are connected imitates spine-curve to fit human back. So, the proposed device can retain entire range of trunk. Target pressure to correct posture is determined from the mathematical model of artificial muscle. In this paper, the structure of device is described, and control method to retain posture based on artificial muscle model is discussed. Finally, effectiveness of the device is verified from experiments in which subject wears this device actually. We reveal correcting trunk posture by using the device from the results.
著者
滝島 勇希 吉田 一也 齊藤 梓 川上 勝 古川 英光
出版者
一般社団法人 日本機械学会
雑誌
機械材料・材料加工技術講演会講演論文集 2018.26 (ISSN:2424287X)
巻号頁・発行日
pp.403, 2018 (Released:2019-05-25)

Various kinds of underwater exploration techniques have been developed. For instance, submersible research vehicles and autonomous underwater vehicle (AUV) have been used for observation of underwater conditions, in addition to the technique of fixed-point observation. However, such research vehicles and conventional AUV are difficult to control, are expensive, and are usually made with non-biodegradable materials such as metals. In contrast, jellyfish is the most efficient swimmers, traveling for long distance with saving energy by drifting in the ocean, its body can be decomposed after death, and safe for surrounding creatures. Therefore, we are developing the jellyfish-mimic AUV using a hydrogel. For designing a Jellyfish-mimic AUV robot, it is preferable to introduce a soft actuator driven by water pressure, as it requires low electric power and it is eco-friendly. In this study, we prototyped a Jellyfish-AUV robot using a soft material and a soft actuator. While it is ideal to make a robot body with hydrogel it is difficult to make the actuator with hydrogel.
著者
田中 直行
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.65, no.638, pp.4213-4215, 1999-10-25 (Released:2008-02-26)
参考文献数
4
被引用文献数
1 1

In the new method of calculating elliptical Hertz contact pressure described here, an elliptic integral is not necessary. Even the simplest numerical integration yields a Hertz contact pressure within 0.005% of the theoretical spherical contact pressure. Dimensionless parameters calculated using this method agreed well with the values given in the references. Elliptical Hertz contact pressure can thus now be calculated using a spreadsheet program for personal computers.
著者
平田 勝哉 川北 正寿 飯島 高善 古賀 光泰 紀平 光彦 舟木 治郎
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B編 (ISSN:18848346)
巻号頁・発行日
vol.77, no.776, pp.1111-1126, 2011 (Released:2011-04-25)
参考文献数
12
被引用文献数
1

The aerodynamic characteristics of airfoils have been researched in higher Reynolds-number ranges more than 106, in a historic context closely related with the developments of airplanes and fluid machineries in the last century. However, our knowledge is not enough at low and middle Reynolds-number ranges. So, in the present study, we investigate such basic airfoils as a NACA0015, a flat plate and the flat plates with modified fore-face and after-face geometries at Reynolds number Re < 1.0×105, using two- and three-dimensional computations together with wind-tunnel and water-tank experiments. As a result, we have revealed the effect of the Reynolds number Re upon the minimum drag coefficient CDmin. Besides, we have shown the effects of attack angle α upon various aerodynamic characteristics such as the lift coefficient CL, the drag coefficient CD and the lift-to-drag ratio CL/CD at Re = 1.0×102, discussing those effects on the basis of both near-flow-field information and surface-pressure profiles. Such results suggest the importance of sharp leading edges, which implies the possibility of an inversed NACA0015. Furthermore, concerning the flat-plate airfoil, we investigate the influences of fore-face and after-face geometries upon such effects.
著者
近藤 修平 Luis CANETE 高橋 隆行
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 2015 (ISSN:24243124)
巻号頁・発行日
pp._1P2-G03_1-_1P2-G03_4, 2015-05-17 (Released:2017-06-19)
被引用文献数
1 1

In this paper, a control method for controlling the dual arm manipulator of the inverted pendulum type assistant robot while performing object hand over is presented. To reduce the complexity and increase the robustness, a partitioned control that separates the body and arm control while treating the other as a disturbance is proposed. To estimate the disturbances, the ESO is implemented on both subsystems. The development of the control and results of actual tests are presented.
著者
沼知 福三郎
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.7, no.28-3, pp.1-9, 1941-09-10 (Released:2008-03-28)

水中における翼型は、高速低圧に於てキャビテーションを発生し、その際における性能は風洞実驗に依ては求められない。然るに廻流水槽における水中翼型の実驗によれば、キャビテーション発生下における翼型性能を求められる。又勿論キャビテーションの発生せざる場合の性能(即ち風洞実驗に該當するもの只空気の代りに水を用ひる)も求められる。この場合も含めて翼型のキャビテーション性能と称した。今回は4箇の翼型に関する結果を報告する。
著者
LUANGARPA Chonlada KOGUCHI Hideo
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.2016, 2016

<p>The conservative integral formulation is developed for calculating the intensities of singularities at a vertex of an interface in three-dimensional piezoelectric bonded joint. The model with three-real singularities is considered. The intensities of singularities of each term of stress singularity are calculated. Various integral areas, which located at various distances from the singular point, are used to investigate an influence of an integral area on an accuracy of results.</p>
著者
富田 直 西垣 英一 表 竜二
出版者
一般社団法人 日本機械学会
雑誌
Dynamics & Design Conference
巻号頁・発行日
vol.2019, 2019

<p>Lightweight structure is required due to ecological considerations. However, the lightweight requirements conflict with noise and vibration (NV) performance. To satisfy both of lightweight solution and NV performance, vibration reduction based on periodic structures is of interest because the periodic structures have wave filtering characteristics which inhibit elastic wave propagation at the frequency ranges referred as band gaps.</p><p>This paper presents a vibration reduction method using the band gaps of periodic shell structures. The frequency of band gaps can be calculated by using reduced FEA model which is applied the Bloch's theory. We can design shapes of unit cells using the calculated band gaps which relate to frequency range with vibration reduction. Frequency response of a finite periodic shell is carried out to demonstrate vibration reduction based on the band gaps. The results of analysis suggested that the band gaps of periodic shell restrain formation of natural vibration.</p>
著者
大畠 英一郎 押領司 一浩
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
巻号頁・発行日
2021

<p>Several high energy ignitions have been proposed to improve ignition performance of diluted combustion recently. One of the major issues in the high energy ignition systems is heat generation of an ignition coil due to increase of power consumption. This study proposes a method to reduce electricity consumption by controlling time distribution of discharge energy while keeping the ignition performance. The following conclusions were obtained as results of verification with an actual engine. (1) A concept for reducing the power supply-demand difference that does not inhibit flame core growth was proposed. (2) To reduce the power supply-demand difference, an ignition coil with an additional active coil was fabricated to enable time distribution control of ignition energy. (3) By controlling the time distribution of ignition energy, both energy saving and ignitability of ignition were achieved, and the prospect of net fuel consumption improvement was obtained.</p>
著者
関口 久美
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.27, no.173, pp.85-95, 1961-01-25 (Released:2008-03-28)
参考文献数
7

The mechanical properties of rubber vibration isolators depend on the amplitude, frequency, temperature, inclination and mean stress, and have remarkable shape effect. When designing, not only such properties but also the kinds of rubber, the conditions of vulcanization, the influences of blending and coating of different rubbers as to the characteristics of materials have to be considered. Furthermore, the deformation of rubber under usual stress is not infinitesimal. The author has continued calculations and experiments in view of the theory of viscoplasto-elasticity advanced by Prof. Sawaragi and strength of materials. And now it becomes possible to calculate the apparent modulus and spring constant by the successive approximation method. From such results a rational method to design rubber vibration isolators is contrived, considering terms above mentioned as much as possible. In this method using nomographs, design can be expedited with a high accuracy.