著者

松永 信智 岡島 寛 志田 裕紀 松野 大亮

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.851, pp.16-00519, 2017 (Released:2017-07-25)

参考文献数

18

---

To analyze the driving behavior is important for designing a comfortable automatic driving. So far, conventional PID models was widely used to steer the vehicle. It has been assumed that the driver looks at the constant point in conventional PID model. However, all drivers have experiences that the gazing distance changes according to the travel routes, driving situations and driver's characteristics. The PID gain of the steering model is assumed to be modified depending on driver's gazing distance. The facts are familiar, but the relationship between driver's steering gain and the gazing distance has not been clarified yet. If this relation becomes clear, it can be helpful for the comfortable driving assistance and/or automatic driving systems to provide for each driver. The aim of this study is to design a steering model estimated by Particle Swarm Optimization (PSO) depending on gazing distance . The feature of the model is on-line measurement of gazing distance incorporating the gazing distance explicitly into a model. The isolated driving and the following driving are evaluated using a Honda driving simulator. The effectiveness of the model is discussed individually.

著者

深見 開 深潟 康二 平 邦彦

出版者

一般社団法人 日本機械学会

雑誌

流体工学部門講演会講演論文集 2019 (ISSN:24242896)

巻号頁・発行日

pp.OS8-01, 2019 (Released:2020-07-25)

被引用文献数

4 4

---

We use machine-learning-based super-resolution analysis to reconstruct high-resolution flow field data from grossly coarse low-resolution data, for three-dimensional fully developed turbulent channel flow at Reτ = 180. The training data is obtained by three-dimensional direct numerical simulation (DNS). We use an average pooling operation used commonly in image tasks, to prepare the coarse input data set. As a machine learning model, the hybrid downsampled skip-connection multi-scale (DSC/MS) model based on convolutional neural network is utilized in this study. Remarkable about this model are its robustness against rotation/translation of the flow images and its ability to consider multi-scale property of turbulence. The super-resolved flow fields recovered through the proposed machine learning model are in agreement with the reference DNS data in terms of velocity color distributions, root mean squared values of velocity fluctuations and L2 error norm defined as the difference between the reference DNS data and super-resolved flow field. The maximum wavenumbers of streamwise and spanwise energy spectrum recovered by machine learning are increased by the super-resolution reconstruction. The proposed method holds great potential for various applications in experimental and numerical situations to handle the fluid big data efficiently, e.g., PIV measurements and subgrid-scale modeling of large-eddy simulation.

著者

石綿 良三

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 2012.18 (ISSN:24242691)

巻号頁・発行日

pp.321-322, 2012-03-08 (Released:2017-06-19)

---

The phenomena with relation to fluid mechanics are often taken up in books on science for popular readers. However, the explanation on principle of them has been described under misunderstood knowledge on fluid mechanics in many books. It seems the reason that the many authors are not understood fluid mechanics enough. Also, there is the further reason in the descriptions involved mistaken explanations in many books. In present study the mechanism of transmission of so misunderstood explanations has been considered, and the diffusion of them has been investigated. It is also examined and proposed how to prevent the transmission and diffusion of the misunderstood knowledge.

著者

川口 芳男

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.91, no.837, pp.863-864, 1988-08-05 (Released:2017-06-21)

著者

芳賀沼 智美 早瀬 敏幸 井上 浩介 武田 元博

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 2007.20 (ISSN:24242829)

巻号頁・発行日

pp.21-22, 2008-01-24 (Released:2017-06-19)

著者

青木 克巳 武藤 浩司 岡永 博夫

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.775, pp.793-802, 2011 (Released:2011-03-25)

参考文献数

15

被引用文献数

1

---

The present study clarifies the effects of dimples for drag and lift on a sphere with rotation. The sphere with dimples has 328 arc type dimples on its surface uniformly. The present study measures velocity distribution in wake and pressure distribution on a sphere surface, and visualizes flow around a sphere by the spark tracing method for the case in which Reynolds number Re=0.4×105-1.3×105. For the case of a smooth sphere, separation point on deceleration side shifts downstream remarkably as spin rate ratio (circumferential velocity of a sphere / free stream velocity) increases. The pressure distribution on deceleration side decreases compared to that on acceleration side. The wake becomes small and shifts opposite direction of rotation. Therefore, the drag reduces, and the lift becomes negative. For the case of a sphere with dimples, this phenomenon occurs for the case in which critical Reynolds number Re=0.5×105. The separation point on acceleration side shifts downstream, and the separation point on deceleration side shifts upstream as spin rate ratio increases for the case in which super critical Reynolds number Re=1.3×105. The pressure distribution on acceleration side decreases compared to that on deceleration side. In addition, the pressure distribution on outside dimple decreases compared to that on inside dimple. The wake becomes large and shifts direction of rotation. Therefore, the drag and positive lift increase.

著者

吉田 直人 家澤 雅宏 西脇 和弘 髙橋 正樹

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.862, pp.17-00583, 2018 (Released:2018-06-25)

参考文献数

13

---

In recent years, an automatic collision avoidance system has been put into practical use by various automotive companies. In this study, we propose an automatic collision avoidance system for a four-wheel independent drive vehicle using the state-dependent Riccati equation. By designing the state-dependent weighting functions, a control gain is automatically determined, based on the relative relationship with a preceding vehicle and the system can properly perform automatic braking and automatic steering. Moreover, by updating the state-dependent linear representation obtained from a nonlinear vehicle model in each control cycle, we design a control system in consideration of a change in vehicle dynamics due to vehicle velocity. Therefore, this study verifies the effectiveness of the automatic collision avoidance system using the state-dependent Riccati equation. We compare the performance of the proposed method with constant weight cases. The simulation results show that the proposed method can automatically adjust the control gain and properly avoid a collision by braking and steering to change the relative relationship with a preceding vehicle.

著者

本田 博

出版者

一般社団法人 日本機械学会

雑誌

年次大会 2014 (ISSN:24242667)

巻号頁・発行日

pp._S2010306-, 2014-09-07 (Released:2017-06-19)

---

In this report, woman global human capitals (WGHC) and woman global engineers and scientists (WGE&S) are grouped into several categories, and education and qualification required to be a variety of high-level global professionals and role of industry and economy focused education, among others, are discussed. It is generally said that women can relatively, easily play a leading and active role in professions such as medical doctors, lawyers, teachers and professors in Japan, as compared with the other professions, such as those at industry in Japan, with males occupying a majority of manegement and other high level key positions. Since the equal opportunity law was put in to effect in 1985 in Japan, opportunities for women professionals have been increasing in this age of global economy. Issues of WGHC and WGE&S are, therefore, discussed with situations in both Japan and overseas nations taken into account.

著者

石綿 良三 根本 光正 山岸 陽一 萩野 直人

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 2014.63 (ISSN:24242748)

巻号頁・発行日

pp._407-1_-_407-2_, 2014-03-18 (Released:2017-06-19)

著者

鈴木 敦 藤岡 和正 桑原 平吉 高崎 利夫

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.62, no.595, pp.1172-1177, 1996-03-25 (Released:2008-03-28)

参考文献数

3

---

This study describes the transient temperature distribution in a cooling apparatus for high-power semiconductor devices used to drive motors of electric rolling stocks. The cooling apparatus is composed of heat pipes. In the model for simulation, we substituted solid elements for heat pipes, and determined their thermal properties by experiment. Consequently, the heat transfer rate of heat pipes can be obtained by a heat conduction analysis. Calculations show that when heat generation in the device changes, the temperature of cooling apparatus changes more slowly than that of the devices. A comparison between calculations and experiments confirms the accuracy of the modeling and prediction method.

著者

森西 洋平

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.62, no.604, pp.4098-4105, 1996-12-25 (Released:2008-03-28)

参考文献数

8

被引用文献数

12 10

---

In this report, finite difference schemes in staggered and collocated grid systems are considered in light of the analytical requirements that were discussed in the first report. The standard second-order accurate finite difference scheme with divergence form in a staggered grid system is proper. Proper second-order accurate advective and skew-symmetric forms have been proposed in the staggered grid system. Existing fourth-order accurate convective schemes in a staggered grid system are not proper. Proper higher-order accurate finite difference schemes in a staggered grid system are proposed. This is novel because higher-order staggered grid schemes that conserve momentum and kinetic energy simultaneously do not previously appear in the literature. The pressure term is not conservative in the kinetic energy equation in the collocated grid system, although we can construct proper-second and fourth-order accurate convective schemes in this system.

著者

朝倉 希一

出版者

一般社団法人 日本機械学会

雑誌

機械學會誌 (ISSN:24331546)

巻号頁・発行日

vol.37, no.Suppl, pp.88-100, 1934-08-06 (Released:2017-08-01)

著者

木村 仁 遠藤 真美 小関 道彦 伊能 教夫

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.74, no.740, pp.806-813, 2008-04-25 (Released:2011-03-04)

参考文献数

17

被引用文献数

1 2

---

A phenomenon that passengers are getting sleepy is often found in running cars or trains. If a mechanism can reproduce this phenomenon, it is feasible to put insomnia patients or infants to sleep without any harmful effects. This will bring extreme benefit for insomnia patients or parents of babies. The purpose of this study is to elucidate the sleep-inducing factors of running cars or trains, and the final goal is to develop a machine which reproduces the environment to put people to sleep. For the first step of this study, we investigated the relationship between sleepiness and vibrations on several trains. The sleepability of each train is discussed by the ratio of sleeping passengers. According to the vibration analyses, the results suggest that comfortable vibration for sleep has mainly low-frequency (2 Hz) vibration with particular fluctuation. In addition, it is also guessed that low level jerks contribute the sleepability.

著者

目加田 融

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.90, no.829, pp.1495-1499, 1987-12-05 (Released:2017-06-21)

著者

石橋 正二郎 田中 聖隆 前田 洋作 吉田 弘

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 2021.26 (ISSN:24242691)

巻号頁・発行日

pp.17C09, 2020-03-13 (Released:2021-03-02)

---

There are lots of knowledge gaps concerning the sea ice of the Arctic Ocean, such as sea ice thickness, sea ice dynamics and sea ice – ocean interactions. Therefore JAMSTEC is now developing a special platform that will be able to move under ice and measure various kinds of data continuously and automatically. It is an intelligence underwater drone for the Arctic Ocean named as COMAI-Drone (COMAI-Drone:Challenge of Observation and Measurement under Arctic Ice - Drone). Now its proto-type have been already designed and initiated to build. Additionally, some aid systems, which can detect its position, can detect the relative direction to a support ship and can communicate between the drone and the support ship, are now developing. At the same time, watertank-tests and field-tests have been conducted gradually. In near future, COMAI-Drone will collect invaluable data under the sea ice in the Arctic Ocean. In this paper, its outline including its mechanism, functions and operation system are described.

著者

齋藤 款文 重藤 文彬 高島 俊

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 2014 (ISSN:24243124)

巻号頁・発行日

pp._1A1-D07_1-_1A1-D07_4, 2014-05-24 (Released:2017-06-19)

---

As one field of sports, there is a game of bike trial. Riders operate mountain bicycles with various advanced techniques. The purpose of this research is to create a bike trial robot that can operate a mountain bicycle and perform various maneuvers such as jumping, bike wheelie and etc. The bike-trial robot is able to clear level differences and ditches which other wheeled type robots cannot clear such obstacles and also cannot intrude into narrow spaces. Therefore, it is possible to use the bike-trial robot in the means of mobility at disaster sites. In this paper, in order to control the robot, it is studied how to generate the joint trajectories for maneuvers, for example, Daniel or Wheelie. The prototype physical model of bike-trial robot for experiments is designed and constructed on a scale of two to five.

著者

篠木 俊雄 前田 毅 舟木 治郎 平田 勝哉

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.787, pp.415-419, 2012 (Released:2012-03-25)

参考文献数

8

被引用文献数

3 3

---

Supposing the design of ethanol steam-reforming reactors, the authors conduct experiments for Cu/ZnO/Al2O3 catalyst. Using a household-use-scale reactor with well-controlled temperature distributions, the authors compare experimental results with chemical-equilibrium theories. It has revealed by Shinoki et al. (2011) that Cu/ZnO/Al2O3 catalyst shows rather high performance with high hydrogen concentration CH2 at low values of reaction temperature TR. So, in the present study, the authors reveal the influences of liquid-hourly space velocity LHSV upon concentrations such as CH2, CCO2, CCO and CCH4 and the influence of LHSV upon the ethanol conversion XC2H5OH, in a range of LHSV from 0.05 h-1 to 0.8 h-1, at S/C = 3.0 and TR = 520 K. And, the authors reveal the influences of the thermal profile upon CH2, CCO2, CCO, CCH4 and XC2H5OH, for several LHSV's. To conclude, with well-controlled temperatures, the reformed gas can be close to the theory.

著者

梶島 岳夫

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.60, no.574, pp.2058-2063, 1994-06-25 (Released:2008-03-28)

参考文献数

16

被引用文献数

29 33

---

A proper finite difference method based on the gradient/convective form of the equation of motion of incompressible fluid is discussed. The gradient form discretized on the staggered grid has essentially the same conservation properties as those of the divergence/momentum-conservative form or the quadratic-conservative form under some conditions. First, the mass continuity should be numerically satisfied. Second, the numerical consistency between the mass continuity and the momentum convection should be satisfied. The gradient form evaluated at midpoints between velocity points in the direction of convection, rather than directly calculated at velocity points, meets this requirement. In this paper, through mathematical description of the above-mentioned features, the performance of the higher-order finite difference method for the gradient form is demonstrated.

著者

細川 瑞彦

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:24242675)

巻号頁・発行日

vol.109, no.1054, pp.738-739, 2006-09-05 (Released:2017-06-21)

著者

永瀬 和彦

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.54, no.504, pp.1852-1860, 1988-08-25 (Released:2008-02-21)

参考文献数

7

被引用文献数

1

---

Many experiments have been made to clear the true state of adhesion coefficient μ which significantly affects the performance of rolling stock. However, such experiments have been made mainly in laboratory rooms, and the experiments made on main lines have been simply a medley of data only at the spot of wheel slipping. The author employed a "Slipping adhesion test truck" built on a new idea of realizing the measurement of μ continually while running, and observed the true state of μ along the mainlines. From the results thus obtained, the author derived the statistically processed μ, and analyzed the relation between μ and the rate of wheel slipping. In addition, the author referred to the various factors that reduced the value of μ.