著者

古性 裕之 毛利 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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.856, pp.17-00203-17-00203, 2017 (Released:2017-12-25)

参考文献数

14

被引用文献数

1

---

We propose curve contour detection algorithm for road white line detection based on Helmholtz principle. White line detection is widely used in driver support systems used mainly in highway or major arterial road. As the common road will be the target of operational area for autonomous vehicle, it is thought to be necessary to develop a new detection algorithm that can deal with various types of road. This paper proposes model-less algorithm that is constructed on a new edge feature inspired by Helmholtz principle through the analysis of the limit of Hough transform. This feature is basically same as Hough defined feature of edge count on the line except two remarkable points. The one is the restriction of count area and the other is the way of count which affords to detect curve line as well as straight line. Implementation by convolutional neural network is explained and the relation between tunable parameters and the detection performance as well as the processing time are discussed. Comparison between conventional methods such as Hough transform or machine learned contour detection algorithm BEL is explained for test image and images taken by on-board camera to show the superiority of proposed algorithm. We demonstrate that proposed algorithm that can apply to diverse road environments but is hardly affected by noise can be realized.

著者

矢野 利明 伊藤 献一

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.48, no.431, pp.1392-1401, 1982-07-25 (Released:2008-03-28)

参考文献数

10

---

火花点火メタノールエンジンの排気系において, 未燃メタノールの酸化過程には, NOからNO2への変換反応により生成されるOHラジカルが, O2の存在と共に重要であることを, 反応動力学モデルを用いて説明し, 実験結果と対比させた. メタノールの消滅速度は, NO濃度の高い理論当量比付近において最大となる. 一方, ホルムアルデヒド濃度は, O2濃度が高く, しかもNO濃度の低い場合に高くなることが明らかとなった.

著者

上甲 康之 黒澤 真理 高橋 幸太郎

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.856, pp.17-00140-17-00140, 2017 (Released:2017-12-25)

参考文献数

5

被引用文献数

1

---

This paper verifies the validity of the prediction model of clothes behavior by using random number. Outer tub of a front-loading washer-dryer is supported by the vibration isolation structure because the imbalance of clothes inside the drum causes vibration in dehydration. The imbalance beyond an acceptable level is modified by the dehydration control system to reduce the vibration. However, the modification of imbalance causes an extension of operation time. Therefore, it is important to estimate the numbers of modification in initial design stage in order to reduce vibration and operation time. In this study, dehydration simulator was proposed to estimate the numbers of modification using Monte Carlo approach. This simulator consists of three steps; the first step is to generate random numbers following the probability distribution of clothes behaviour obtained by experiment, the second step is to count the random numbers beyond threshold as the numbers of modification, and the third step is to repeat previous steps and to obtain the average number of modification. As a result, the maximum absolute difference of the average number of modification between experiment and prediction was 1.6 times. In addition, the relationship between the threshold and the average number of modification requires about 80 days to be obtained in experiment, but it is shown that the relationship was predicted within a day in proposal method. These results would provide the validity of the proposed approach.

著者

長山 格

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

vol.84, no.857, pp.16-00366-16-00366, 2018

---

<p>An intelligent snatching detection system (ISDES) for autonomous detection of criminal incident by using machine learning approach is presented in this paper. Also, ESSM (Extended Snatching Situation Model) is presented to give an effective definition of the whole snatching situation including victim's behaviors. Rule-based decision making and machine intelligence are primary components of the proposed system to act without being explicitly programmed for data dispersion. Some motion characteristics are determined from video streams, also using the ESSM and machine intelligence, the system automatically classifies the situation of the video streams into criminal or non-criminal scenes. After constructing the system, we use test sequences that are continuous video streams of human behavior consisting of several actions in succession. We consider six types of scenarios for the experiments including victime's behaviors as the snatching incidents performed with motorcycle. The experimental results show that the system can effectively detect criminal scenes with an accuracy of 95.83 %.</p>

著者

千本 一夫

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.34, no.174, pp.1485-1493, 1931-10-01 (Released:2017-08-01)

著者

高見 創 嵯峨 信一

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.844, pp.16-00337, 2016 (Released:2016-12-25)

参考文献数

13

被引用文献数

1

---

Brake squeals phenomena of the disc brake system for railroad cars were reproduced and were investigated in the test stands using a full-size brake rotor, a wheel, a floating caliper and a brake pad. Brake squeals of the disc-brake apparatus occurred at a low speed of 20 km/h or less, and the magnitude of brake squeals increased as the average braking force increases until it was saturated. Frequencies of the brake squeals exceeding the background noise of the test facility are 800 Hz, 2 kHz, 3.2 kHz, and 6.3 kHz. The largest squeal of 6.3 kHz was radiated from the leading side of the pad and the rotor, and coupled vibrations between the rotor and the pad were attributed to the self-excited vibration induced by the dry friction. To measure the vibrations of the rotating disc at the time of brake squeals, vibration measuring systems operating by wireless power supply were installed in the rotating axle. As a result, one-third octave band analysis of brake squeals at 6.3 kHz and at 3.2 kHz approximately coincides with the vibration of both the rotor and pad, and the coupled vibration tends to grow larger in the high friction coefficient range. Furthermore, these frequencies agree well with the natural frequency of the rotor examined using the scanning laser doppler vibrometer. The mode shapes and amplitude of rotor vibrations at the time of brake squeals are significantly affected by the number of bolts and their fastening positions to the wheel.

著者

神田 睦月 徳田 献一 入部 正継 森田 成昭 齊藤 安貴子 八上 修一 小堀 亮

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.2017, pp.1A1-C02, 2017

---

<p>In recent years, aging of agricultural workers has progressed, attention is paid to ICT conversion of agriculture and Functional food with health maintenance effect. Raspberry contains a large amount of compounds that have a high health maintenance effect, which takes time and labor for cultivation. The purpose of this research is to construct an image processing system that recognizes color and position information in order to check whether harvesting of raspberries is possible under an indoor environment. As research contents, RGB values of colors of berries at various stages were calculated from spectral analysis results of berries and compared with actual fruit photos. We also classified colors in the image using machine learning and verified its accuracy.</p>

著者

福田 勝己 西村 良弘 鈴木 隆之 池田 泳樹 内部 銀二

出版者

一般社団法人 日本機械学会

雑誌

山梨講演会講演論文集 2015 (ISSN:24242705)

巻号頁・発行日

pp.12-13, 2015-10-17 (Released:2017-06-19)

著者

尾崎 公一 福田 忠生 西 亮 椎森 康雄 早川 悌二

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.73, no.726, pp.279-284, 2007-02-25 (Released:2011-03-02)

参考文献数

4

被引用文献数

1

---

In order to investigate the flow of molten metal in a cavity of a die, experimental simulation was carried out by using water flow model. The experimental cavity was constructed of a backward step configuration for test zone, in which flow behavior and air exhaust process from the cavity were investigated. With rib material installed down the step, its effect on air exhaust promotion was examined for various flow velocities. The main results obtained are as follows : Air exhaust from the cavity is remarkably promoted by installation of rib because the strong turbulence around the rejoining potion of two different flows, which are separated by the rib at the upstream, broke rapidly the trapped air into small bubbles. The time taken to complete air exhaust process is in inverse proportion to the flow velocity in the high velocity region, while it is proportion to the flow velocity to the -2.27th power in the low velocity region.

著者

橋詰 剛 宮本 武司 赤川 久 辻村 欽司

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.66, no.641, pp.286-293, 2000-01-25 (Released:2008-03-28)

参考文献数

15

被引用文献数

2 1

---

By injecting fuel at the very early stage of compression stroke and thus creating homogeneous lean mixture before ignition, (PREDIC;PREmixed lean DIesel Combustion), simultaneous reduction of NOx and smoke was obtained. However, since increasing the mixture equivalence ratio cause knocking, it was difficult to operate at higher load conditions. In this study, in order to reduce combustion rate at high load conditions in a premixed compression ignition engine, multiple stage injection method and EGR were combined, and heterogeneous mixture was made before ignition. The engine test results showed that NOx emissions could be reduced to less than 50 ppm, without knocking even at full load conditions. In addition, smoke emissions were also maintained below invisible level. It can be understood that the premixing of fuel was advanced, smoke was reduced, and EGR rate was increased, resulting lower heat release rate and NOx emissions.

著者

石田 正弘 陳 之立 植木 弘信 山田 武

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.61, no.590, pp.3518-3523, 1995-10-25 (Released:2008-03-28)

参考文献数

11

被引用文献数

1

---

To reduce the level of exhaust emissions and to improve the ignition characteristics, the effect of pilot injection on combustion was examined experimentally in a turbocharged direct-injection diesel engine, and was analyzed theoretically using a two-zone combustion model. The pilot injection effect was compared with the combustion in the injection without pilot injection and also with the effect of fuel additive as an ignition improver in two kinds of fuel : high-quality fuel having a cetane index of 57 and low-quality fuel having that of 40. It is found that the pilot injection effectively reduces ignition delay at the retarded injection timing, under the low-load condition, and in the case of low-cetane fuel. The ignition delay of the main injection is reduced to about a half of that of the injection without pilot injection by the pilot injection with the short interval between pilot and main injection. The ignition delay of the low-cetane fuel is reduced to that of the high-quality fuel by a small amount of pilot injection, or by adding 1% of the ignition improver.

著者

橋詰 剛 宮本 武司 赤川 久 辻村 欽司

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.66, no.652, pp.3233-3240, 2000-12-25 (Released:2008-03-28)

参考文献数

13

---

Simultaneous reduction of NOχ and smoke under high load conditions could be obtained by MULDIC(MULtiple stage DIesel Combustion) where mixture was made stratified before ignition. In this investigation of the basic characteristics of MULDIC, gaseous fuels (DME, Propane) were charged into the intake air which led to the creation of homogeneous lean mixture, and liquid fuel was injected into the cylinder and made rich mixture. The results of the engine test showed that NOχ emissions could be reduced to less than 100 ppm and smoke emissions were also maintained 0 FSN even at higher loads. Moreover, homogeneous rich mixture test results showed that low smoke combustion could be obtained under equivalence ratio of 1.6. In MULDIC, increasing the ignition delay period of injected fuel, soot formation rate was decreased, because over rich region was avoided.

著者

長山 格

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

2018

---

<p>An intelligent snatching detection system (ISDES) for autonomous detection of criminal incident by using machine learning approach is presented in this paper. Also, ESSM (Extended Snatching Situation Model) is presented to give an effective definition of the whole snatching situation including victim's behaviors. Rule-based decision making and machine intelligence are primary components of the proposed system to act without being explicitly programmed for data dispersion. Some motion characteristics are determined from video streams, also using the ESSM and machine intelligence, the system automatically classifies the situation of the video streams into criminal or non-criminal scenes. After constructing the system, we use test sequences that are continuous video streams of human behavior consisting of several actions in succession. We consider six types of scenarios for the experiments including victime's behaviors as the snatching incidents performed with motorcycle. The experimental results show that the system can effectively detect criminal scenes with an accuracy of 95.83 %.</p>

著者

大庭 拓也 山田 幸一 岡田 信之 相馬 仁 谷藤 克也

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.75, no.757, pp.2459-2467, 2009-09-25 (Released:2017-06-09)

参考文献数

17

被引用文献数

3 2

---

Rolling stock has been generally inspected and maintained on the basis of the preventive maintenance. However, the reliability of the sensors and information technology has drastically improved, and with this background the objective of this research is to develop the condition monitoring system for the bogies of the Shinkansen cars. This paper describes an algorithm for detecting fault in some parts of bogies. This scheme is based on the statistic analysis of vibration acceleration during some period. This algorithm named peak average method detects the difference of the vibration peak distribution between fault cases and normal ones. For examining the possibility to detect fault in the bogie, experiments simulating some fault modes in bogie parts are conducted in the rolling stock test plant at Komaki Research Center of CJRC. From the results of these experiments, we can show the reliability and the validation of this scheme for monitoring conditions of Shinkansen bogies developed in this research.

著者

近久 武美 湯山 亮 菱沼 孝夫

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.67, no.658, pp.1563-1570, 2001-06-25 (Released:2008-03-28)

参考文献数

11

被引用文献数

5 7

---

Investigation on diffusion process is required in variety of field such as chemical reaction, combustion, and environmental studies. However, there is no appropriate index for analyzing degree of homogeneity and scales of the clouds in diffusion field. This paper pressents Entropic Method for determining the homogeneity degree and the scale of the heterogeneous clouds based on the statistic-entropy concept. The results of the investigation on the performance and characteristics of the method showed good correspondence between the analyzed results and the states of the tested pictures. A method for determining a mean effective diffusion-coefficient from the pictures is also discussed. The paper proposes an analitical method available for the study on diffusion phenomena.

著者

吉山 定見 浜本 嘉輔 冨田 栄二 穂積 洋輔

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.64, no.626, pp.3479-3484, 1998-10-25 (Released:2008-03-28)

参考文献数

13

---

The cross-sectional images of turbulent premixed flames of homogeneous fuel-air mixture in an engine cylinder were obtained by a laser tomography, and the fractal characteristics were investigated. It was observed that in an engine cylinder under high pressure condition, the turbulent flame was a smaller and more complicated structure, comparing with that under the lower pressure condition in a closed combustion chamber. The fractal dimension increases with the increase of the turbulence intensity and mixture density. The fractal dimension is expressed as a function of the increase ratio of mixture density and the ratio of turbulence intensity to laminar burning velocity. The inner cutoff scale of turbulent flames is expressed as a function of Karlovitz number.

著者

緒方 正則

出版者

一般社団法人 日本機械学会

雑誌

年次大会講演論文集 2010.5 (ISSN:24331325)

巻号頁・発行日

pp.253-254, 2010-09-04 (Released:2017-08-01)

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Author already reported the field work results of waterwheel that has scooping plates and chains that was preserved in the Wu Institute of Wuxi in Jiangsu province of China. The waterwheel was called Longguo che (dragon waterwheel). By using the measurement values of the parts, the standard of the ruler was clarified. The author reported a field survey result of the length of the ruler about 4600 years before, called "Nippur cubit" which was named by the excavation place. Including these reports, the results that examined the concrete numerical value of the ruler in the East and West world based on literature and field survey is reported in this paper.

著者

安達 瑛二 中村 吉彦 戸次 良治 大西 郁生

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.62, no.598, pp.2511-2515, 1996-06-25 (Released:2008-02-26)

参考文献数

2

---

To materialize actual designs in computer-aided design, we presented a method to determine structural dimensions in order to make all design requirements accomplish their respective objective values, using the attainability and simultaneous equations with several unknowns. However, most of the designs have no theoretical design formula or sensitivity coefficients. This paper presents an approximation method to identify sensitivity coefficients by trial production evaluations of the designs. The coefficient matrix is specified between k th revised values of the attainabilities and k th revised values of the design variables, and made into a square or a triangular matrix by neglecting insignificant variables. The matrix is solved iteratively until all coefficients converge. This paper also presents a multiobjective satisfactory design using the identified coefficients to prove the effectiveness of the identification, comparing the identified coefficients with the theoretical ones.

著者

古賀 倫子 佐藤 太一 松野 隆太 蔭山 怜

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.855, pp.17-00220-17-00220, 2017 (Released:2017-11-25)

参考文献数

9

---

We investigated the damping mechanism of a granular material damping system applied to reducing vibration in structures that have a high natural frequency and small vibration displacement. Experiments were conducted under several conditions of total mass of granules. We also constructed a computational model of a single-degree-of-freedom vibration system with a granular material damper to study the mechanism of a granular material damping system. On the basis of the fundamental idea that the damping effect of a granular material damper is governed by the motion of the granules, we classified the granular materials as “relative motion mass” and “equivalent added mass” in the translational motion and as “rotating mass” and “not rotating mass” in the rotational motion and then considered the relationship of these mass classes to the damping characteristics. In this report, we examine the relationships of the motion of the granular materials, “relative motion mass” and “rotating mass”, and damping ratio by means of experiments and calculations for structures that have a high natural frequency and small vibration displacement.

著者

藤田 勝久 森朝 昭典

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.855, pp.17-00206-17-00206, 2017 (Released:2017-11-25)

参考文献数

10

---

In this paper, dynamic stability analysis methods of a beam subjected to a confined annular axial flow are dealt with. Such structures are submarine resources production pipeline, reactor core structures of nuclear power plants, high-speed trains passing thorough a tunnel, a piping system in the field of ocean mining, and so on. The relation between the annular axial flow velocity and the unstable dynamics of structures are clarified. We have compared two analysis methods which can evaluate the dynamic instability of such structures. In first analysis method, the fluid is treated as viscous fluid, and is governed by the Navier-Stokes equation, and the beam structure is treated as the Euler-Bernoulli beam. This is called as the viscous fluid solution namely NS solution hereafter. In second analysis method reported by (Rinaldi and Paidoussis, 2012), the fluid is treated as ideal fluid. Then the viscosity effect is added to the equation of motion. This is called as the ideal fluid solution namely R&P solution hereafter. The complex eigenvalue analysis of the fluid structure coupled equation of motion is performed in order to clear up the dynamic instability. Performing the parametric studies, the comparison between both solutions is investigated. When the fluid viscosity becomes large, the difference in the critical velocity between the viscous fluid solution namely NS solution and the ideal fluid solution namely R&P solution is found to be generated. The destabilization effect appears due to the fluid viscosity force terms of the added stiffness of the fluid-structure coupled equation only in the viscous fluid solution.