著者

田島 利基 李 沛譲 朱 赤

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.20-00372, (Released:2021-04-09)

参考文献数

15

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In recent years, electric powered wheelchairs have become indispensable in long-term care. Up so far, many electrically powered wheelchairs have been developed to reduce the burden of caregivers, in which omnidirectional electrically powered wheelchairs attracted researchers’ attentions because these types of EPWs can be used without stress in narrow and/or crowded spaces. In this research, we have developed an omnidirectional wheelchair typed mobile assistive robot with power assistance. In addition, traditional electric powered wheelchairs use a joystick or a force sensor as the operation interface. Joysticks cannot be used by the elderly or disabled, and force sensors are too expensive to be used for wheelchairs. In this study, we have developed a new type of Human Machine Interface (HMI) using a mechanism that can detect force at low cost by using linear potentiometers and compression coil springs instead of a force sensor. The accuracy of the developed HMI is verified, and its effectiveness is confirmed in practical use. Further, we conducted power assisted experiments in forward/backward and lateral directions and turn on the spot using an admittance control with the developed HMI attached to our omnidirectional wheelchair robot. From the experimental results, the developed HMI control accurately measures the forces applied on the wheelchair by the user. Finally, a power-assisted experiment was conducted in the straight direction on a 5-degree slope. These experiments proved that our HMI-based power assist system is effective for omnidirectional wheelchairs.

著者

内田 浩二 齊藤 弘順 立石 又二

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 B編 (ISSN:03875016)

巻号頁・発行日

vol.71, no.712, pp.3076-3081, 2005-12-25 (Released:2011-03-03)

参考文献数

11

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This paper revealed the reason of poor self-ignition quality of alcohol spray from the viewpoint of mixture formation considering fuel properties. Ignition characteristics of Ethanol and Diethyl Ether blended fuels were experimentally investigated with changing their blend ratio in order to clear the effects of fuel's physical and thermal properties on ignition. Experimental results and prediction of mixture formation of blended fuels showed that stoichiometric air/fuel ratio (Lth) and latent heat for vaporization (γ) were main parameters on ignition. Alcohol spray becomes lean situation faster than conventional diesel fuel such as Gas oil due to their smaller Lth. On the contrary, temperature rise of alcohol spray up to ignition point is slower than Gas oil caused by their larger γ.This causes poor self-ignition quality of alcohol spray. Namely, it is difficult for an alcohol spray to be a mixture of suitable mixing ratio and temperature for self-ignition at the same time and place.

著者

伊藤 瑛里 西脇 眞二 泉井 一浩 山田 孝之

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.2020, 2020

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<p>This paper proposes a scheme for imposing geometrical constraints in topology optimization to obtain structures considering the visibility of the product user, based on a fictitious physical model. First, a level set-based topology optimization method is concisely introduced, and geometrical requirements for the visibility are clarifid. A fictitious physical model described by a steady-state advection-dffusion equation is then constructed based on the requirements. In this model, virtual heat sources correspond to material domains and the advection direction is aligned with a radial direction around a view point. The visibility is evaluated by the values of the fictitious physical model, and the regions to see, where the value of the fictitious physical field is high, represent blind area. Next, an optimal problem is introduced based on the fictitious physical model. Finally, in the numerical examples, the proposed method yields optimal structure considering the visibility, confirming the validity and the utility of the proposed method.</p>

著者

三木 忠直

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:00214728)

巻号頁・発行日

vol.62, no.480, pp.133-145, 1959

著者

近藤 滋

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

巻号頁・発行日

vol.2017, 2017

著者

乾 公昭 森川 昌英 橋本 雅文 所谷 康平 高橋 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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.854, pp.17-00061, 2017 (Released:2017-10-25)

参考文献数

21

被引用文献数

1

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This paper presents a method of correcting distortion in 3D laser-scan data from in-vehicle multilayer laser scanner. A robot identifies its own 3D pose (position and attitude) in a laser-scan period using the normal-distributions transform (NDT) scan-matching method. Based on the pose information, the robot's pose in a period shorter than scan period under the assumption that the robot moves at almost constant linear and turning velocities. The estimated pose of the robot is applied to map laserscan data onto a world coordinate frame. Subsequently, the robot again identifies its own 3D pose from the mapped scan data using NDT scan matching. This iterative process enables the robot to correct the distortion of laser-scan date and accurately map the laser-scan data onto the world coordinate frame. Two methods for correcting the laser-scan data are presented: linear-interpolation based and Kalman-filter based methods. The former applies the extrapolation and interpolation to estimate the vehicle pose, while the latter applies the prediction, estimation, and smoothing. Experimental results of mapping a signal light in a road environment show the performance of the proposed two methods.

著者

東洋工業株式会社

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.85, no.766, 1982

著者

福田 敏男 小林 寛

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

巻号頁・発行日

vol.52, no.474, pp.750-757, 1986

被引用文献数

1

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This paper presents a new concept of a flexible mobile and versatile shape reconfigurable control mechanism of a robot, called a versatile robotnoid (Vroid), which can be applied for plant maintenance works and other outdoor operational works, where its working environments are restricted due to mobil space and terrain. The Vroid I based on the multiple link-wheel mechanism has abilities of passing through rough terrains, passing over obstacles and going up and down stairways. Compared the Vroid I with conventional wheel, crawler and legged locomotion types of the mobile mechanisms, the proposed one is considered to be superior to those from the viewpoint of flexibility and adaptability to working environments. Utilizing the redundancy of joints in degrees of freedom, a method of the joint static control sequence is proposed to minimize the torques required to joint rotation under some constraints, which can easily be solved by the linear programming approach.

著者

柴田 翔平 鳴尾 丈司 加瀬 悠人 稲毛 正也 山本 道治 森 正樹 浦川 一雄 廣瀬 圭 神事 努

出版者

一般社団法人 日本機械学会

雑誌

シンポジウム: スポーツ・アンド・ヒューマン・ダイナミクス講演論文集 2018 (ISSN:24329509)

巻号頁・発行日

pp.A-18, 2018 (Released:2019-05-25)

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The purpose of this study is to examine the accuracy of the system analyzing pitching data using baseball-type sensor (MAQ) and to measure kinematic parameter (ball velocity, spin rate, and spin axis) of baseball pitches by various pitchers. The accuracy of the developed system using a 3D motion analysis system and the high-speed cameras were examined. The spin axis of pitched ball was calculated from data of 12-axis sensor using the sensor fusion by extended Kalman Filter. The ball velocity and spin rate calculated by MAQ and the 3D motion analysis system showed similar values (ball velocity: r = 0.95 spin rate: r = 0.90). In several data, it was indicated that the spin axis calculated by MAQ, the 3D motion analysis system, and the high-speed camera showed similar values. In addition, there was a correlation between ball velocity and spin rate over the velocity range from 6.7 m/s to 41.0 m/s (n=188). From these results, the developed system can be used to evaluate baseball pitching skill with high accuracy.

著者

小山 達弥 網干 光雄

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.78, no.789, pp.1617-1631, 2012 (Released:2012-05-25)

参考文献数

8

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When there is an undulating wear on overhead rigid conductor line, arc due to contact loss is generated between the conductor line and a pantograph. The arcs cause extreme wear of contact lines and contact strips of the pantograph. However the mechanism of the undulating wear formation has not been clarified. This paper to make clear the mechanism of the formation of the undulating wear through on-site investigation of overhead rigid conductor lines and excitation tests of the pantograph. It was been clarified that the dynamic characteristics of pantograph and the distance between pantograph heads play a causal role in the undulating wear formation. Firstly, a periodic unevenness is generated by mechanical wear that is caused due to the dynamic characteristics of pantograph, especially anti-resonance phenomenon of pantograph. When the wear amplitude of unevenness grows to the extent with which pantographs cannot comply, arc due to contact loss occurs between overhead rigid conduct line and the pantograph. By this arc, electric wear is generated in a hollow of unevenness, then the undulating wear of which wavelength is related to the interval of pantograph head grows.

著者

中野 栄二

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.766, pp.1078-1082, 1982-09-05 (Released:2017-06-21)

著者

小林 秀明 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.74, no.748, pp.2932-2938, 2008-12-25 (Released:2011-03-04)

参考文献数

9

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This paper deals with the effects of axle misalignment of a truck with independently rotating wheels (IRWs) on the wheel lateral force and the flange wear. Since the truck with IRWs lacks for self-steering ability, it is concerned that the wheel continues flange contact with rail due to the effects of axle misalignment in parallelity and the flange wears rapidly under the continuous flange contact condition. Numerical simulations are carried out, using an analytical vehicle model with the axle misalignment. Obtained results are as follows : Even if misalignment is a little, the vehicle with IRWs which dose not have self steering ability tends to run under the flange contact condition, and then continuous lateral force acts between the flange and the rail. The vehicle with IRWs, which has axle misalignment only in the lateral setting, does not have tendency of continuous flange contact. In the range of misalignment in parallelity considered in this paper, the wheel lateral force increases with the increase of the misalignment, and the wheel lateral force of IRW increases more than that of the solid wheelset. The wheel lateral forces generated due to the misalignment are equivalent to the ones generated in the curved tracks, the radii of which make the attack angles corresponding to the misalignment.

著者

島 秀雄

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会誌 (ISSN:24242675)

巻号頁・発行日

vol.60, no.465, pp.1015-1024, 1957-10-05 (Released:2017-06-21)

著者

本多 豊太

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.105, no.1008, pp.738-740, 2002-11-05 (Released:2017-06-21)

著者

Chonlada LUANGARPA Hideo KOGUCHI

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

巻号頁・発行日

vol.2012, pp.70901-70902, 2012

著者

長弘 憲一

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.113, no.1097, pp.257-261, 2010-04-05 (Released:2017-06-21)

参考文献数

9

著者

浅野 浩二

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:00214728)

巻号頁・発行日

vol.122, no.1212, pp.26-29, 2019

著者

一宮 昌司 中村 育雄

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.788, pp.794-810, 2012 (Released:2012-04-25)

参考文献数

62

被引用文献数

4 4

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Investigations on the definition and randomness of turbulence was reviewed at first. Then, the Kolmogorov complexity which measures the randomness were introduced. Numerical and graphic data in the mixing layer which was formed downstream of two-dimensional nozzle exit were compressed with the aid of a compression program. Approximated Kolmogorov complexity, AK, and normalized compression distance, NCD, were obtained. The AK indicated the regularity of the laminar flow and the randomness of the turbulent flow quantitatively. The NCD of the numerical value varied with data length. Between the same data, it approached zero, yet, on the other hand, between different data, it approached unity as the data length increased. The NCD of the numerical value in the natural transition process in the mixing layer increased monotonically downstream. Thus the NCD appears to be the measure of the transition process. In the natural transition process in the mixing layer, the AK of the numerical value and the NCD of the graphic data did not change monotonously in the downstream direction. Thus they contain some uncertainty for the measure of the transition process.

著者

山本 圭治郎 兵頭 和人 石井 峰雄 松尾 崇

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.67, no.657, pp.1499-1506, 2001-05-25 (Released:2008-02-26)

参考文献数

18

被引用文献数

17 23

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In order to realize a power assisting suit for assisting a nurse caring a patient is her arm, a hardness sensor of muscle using load cell and a pneumatic rotary actuator utilizing pressure cuffs have been developed. The power assisting suit consists of shoulders, arms waist and legs made of aluminum, and is fitted on the nurse body. The power assisting suit was originated with the concept of a master and slave system in one body. The arms, waist and legs have the pneumatic rotary actuators. The pneumatic rotary actuators construct with pressure cuffs sandwiched between thin plates. The action of the arms, waist and legs of the nurse were sensed with the muscle hardness sensor utilizing load cell with diaphragm mounted a sensing tip. The dent of the sensing tip corresponds to the hardness of the muscle so that exerting muscle force produces electric signal. This paper gives the design and characteristics of the power assisting suit using the cuff type pneumatic rotary actuators and the muscle hardness sensor verifying its practicability.

著者

宇都宮 登雄 新井 象午 花田 淳一郎

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 2004 (ISSN:24242705)

巻号頁・発行日

pp.277-278, 2004-10-23 (Released:2017-06-19)