著者

木下 俊 呉 魏 廣垣 俊樹 青山 栄一

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.81, no.822, pp.14-00486-14-00486, 2015 (Released:2015-02-25)

参考文献数

13

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Nowadays, industrial dual-arm robots have gained attention as novel tools in the factory automation field for anext generation. We therefore focus on them to flexibly control both the linear motion and the rotational motion of a working plate. However, there has been one problem that it is difficult to measure the synchronous accuracy of two rotary axes without high accuracy gyro sensor. Thus, we proposed a novel method to measure the synchronous accuracy of two rotary axes of working plate with a ball, which keeps a ball rolling around a circular path on it by dual-arm cooperative control and demonstrated that a proposed method is effective to estimate its motion of frequency response. In present report, for widening the range of applications, we tried to keep a ball rolling around rhomboid path which is one of polygonal path on working plate by dual-arm cooperative control and to investigate its characteristic.

著者

西田 勇 前田 正登 川野 常夫 白瀬 敬一

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.840, pp.16-00006-16-00006, 2016 (Released:2016-08-25)

参考文献数

11

被引用文献数

1

---

For several decades, factory automation or unmanned factory productivity has been progressed to realize much higher productivity in manufacturing. However, human centered manufacturing system is getting attention to realize much more flexibility for manufacturing of wide product variety and volume. So it is necessary to provide the safe and efficient environment to workers considering their own physical properties. This study investigated a mechanism of muscle fatigue and proposed a muscular fatigue model to evaluate muscle fatigue progress under several muscular force patterns. Previous studies have already proposed a muscular fatigue model. However, these previous studies discussed about the condition of maximum voluntary contraction. The new point of this study is considering several muscular force patterns including muscle recovery progress. This study proposed the method to estimate the endurance times for keeping constant forces considering the physical characteristics. This study also proposed the method to estimate the iteration numbers for keeping constant forces with interval. To validate the effectiveness of the proposed method, experimental verifications were conducted. The experimental results had a good agreement with the evaluation of muscle fatigue progress using the proposed method although it is necessary to consider the method to raise the precision of determining the physical parameters and the method to decrease the dispersion of experiments derived from the subjective judgement of participants. Success of resolving these issues will provide ergonomically safe and efficient working environments considering the physical properties of each worker.

著者

秋庭 義明 木村 英彦 鶴 尋貴 中村 亜有子

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.74, no.742, pp.879-884, 2008-06-25 (Released:2011-03-02)

参考文献数

18

被引用文献数

1

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Fatigue test system for thin sheets was constructed using an ultrasonic fatigue testing machine. Specimens were fixed at the location where the displacement amplitude became the maximum. The specimen was fatigued under full-reverse bending. Displacement at a fixed edge of the specimen and the deflection of the specimen were measured with a laser displacement gage during fatigue tests. Modal analysis was carried out to determine the dimensions of the specimen and to calculate the applied stress on the basis of the flexural displacement amplitude. The maximum stress was observed on the free side edge near the fixed edge. Two kinds of martensitic stainless steel sheets, SUS301-CSPH and SUS632J1-CSP, were fatigued with the fatigue test system. The thickness of the specimen was 83 and 106μm, respectively. The 3rd vibration mode was selected for fatigue tests. The fatigue cracks initiated from the free side edge of the specimen. For the case of shorter fatigue life, fatigue strength for both stainless steels were almost identical. On the other hand, for longer fatigue life, fatigue strength of SUS632J1 is higher than that of SUS301.

著者

水谷 淳之介 西田 友久 武藤 睦治 今岡 亮 牧野 真一 伊藤 六郎

出版者

一般社団法人 日本機械学会

雑誌

材料力学部門講演会講演論文集

巻号頁・発行日

vol.2006, pp.357-358, 2006

著者

水谷 淳之介 西田 友久 武藤 睦治 今岡 亮 牧野 真一 伊藤 六郎

出版者

一般社団法人 日本機械学会

雑誌

材料力学部門講演会講演論文集

巻号頁・発行日

vol.2006, pp.357-358, 2006

著者

南後 淳 宮原 洋平 高山 将歩 宮田 和揮 鈴木 貴史 佐藤 潤

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.17-00171-17-00171, 2017 (Released:2017-10-25)

参考文献数

15

被引用文献数

1

---

In recent years, many assist devices have been developing to enable the users to walk by an electric control system. However, introducing an electric control system makes the price rise of the device. It is difficult for users to purchase an expensive device, even if it is easy to use. In order to spread an assist device in daily life, a development with a low price and a simple device is expected. The device driven by external power sources disturbs users' independent action, there is a risk that it could be make users' physiologic function decline and users disincentive to do daily actions. An appropriate control system should be constructed in order to avoid an interference between a user's motion and a device's output motion. In case that the control system has the problem, an appropriate assisting motion can not be obtained, and it is in danger of harming to the user's body. So the design of devices is needed to consider for safety. The purpose of this research is the design and the development of a simple device for assisting walking motion which is driven by users' self, considering users' own physical condition. The assist device is designed by using a planar 6-link mechanism which transforms a rotational motion into an oscillating motion. The respective lengths of the links are determined by comparing the movement of the link, which the user's foot is put on, with the movement of the human leg in the action of walking. We optimize the device by using the Genetic algorithm while we consider the max value of input-torque to drive the device. In this study, the device assisting the user's legs are driven by the user's arm. Authors evaluate the device's supporting performance by the method of measuring the leg motion and the EMG of the leg. The transmissibility is also evaluated by the method of measuring the output force with load cells. The results are verified by comparing the values derived from the static analysis. From these results, authors investigated that the driving arm motion interlocked with the assisting leg motion, even though it had only one degree-of -freedom. The measurement result of the transmissibility shows that the output is enough to support the walking motion in the swing phase.

著者

森安 竜大 松森 唯益 永岡 真

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.17-00144-17-00144, 2017 (Released:2017-10-25)

参考文献数

26

---

A topology optimization method is proposed for the design of shallow-flow channels based on quasi-three-dimensional flow models of laminar and turbulent flows. The models for laminar flow and turbulent flow are derived from the Navier-Stokes equations and the Reynolds-Averaged Navier-Stokes (RANS) equations, respectively, by integrating along the direction of channel thickness. The thickness is employed as the design variable in the topology optimization. The design variables are updated using a time-dependent diffusion equation with a design sensitivity which is calculated by a discrete adjoint approach. Numerical examples for minimizing dissipation energy or variance of flow velocity magnitude using the topology optimization demonstrates that the proposed method is capable of finding optimal solutions that satisfy the KKT conditions. In the former example, the design domain was clearly divided into domains where the thickness was either near the upper limit or near the lower limit. However, in the latter example, the thickness was at an intermediate level in almost the whole the design domain. The distribution of the thickness varied depending on the Reynolds number in both examples.

著者

佐藤 皓明 遊佐 泰紀 岡田 裕

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.17-00300-17-00300, 2017 (Released:2017-10-25)

参考文献数

20

被引用文献数

3

---

In this paper, formulations and some computational results of cycle jump method based on the nonlinear finite element method are presented. Problems, involving nonlinear cyclic deformation, such as low cycle fatigue problems can be solved by the proposed cycle jump method. To solve the problems of nonlinear cyclic deformation of structure by the nonlinear finite element method with a cycle-by-cycle approach, a large amount of computational time is generally required. Thus a cycle jump method is presented from a view point of temporal multi-scale analysis. Then, an alternative analytical procedure consisting of three steps is proposed. They are a few cycles of nonlinear analysis in a cycle-by-cycle fashion, computations of jumps of strain history dependent quantities (extrapolations) based on the results of the cycle-by-cycle analysis and a cycle jump for several dozen to several hundred cycles using the results of the extrapolations. The results of cycle jump analyses are presented and their accuracies are critically examined. It was found that the results of several load cycles at the beginning of each cycle-by-cycle analysis step should be excluded from the computations of the extrapolation step.

著者

久野 翔太郎 石川 諭 雉本 信哉 木庭 洋介

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.17-00305-17-00305, 2017 (Released:2017-10-25)

参考文献数

13

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Several adaptive feedforward control methods have been proposed in previous research on active noise control. In those methods, noise control is achieved by adding in a reverse-phase control sound of the same amplitude to noise near an error microphone. Because this method is aimed at controlling only noise near the error microphone, the control area is inherently narrow. Here, we propose an alternative method of noise control for an entire closed space. The proposed method is based on state feedback control and modeling of the acoustic space by the concentrated-mass model. The acoustic space is modeled as masses, connecting springs, and connecting dampers. Further, a loudspeaker as control source is also modeled as a mass-spring-damper system. We previously reported a method for simple one-dimensional acoustic space control. In this paper, we show the design of a control system for two-dimensional acoustic spaces. The acoustic space and loudspeakers are modeled in a concentrated-mass model, and the state feedback control system is realized as a Kalman filter with pole placement. The number of degrees of freedom is reduced by using modal analysis, which reduces the computation time of the controller. Experiments and numerical simulation of the coupled system were conducted to confirm the validity of the analysis model. Noise in the acoustic space was experimentally controlled, with the finding that noise in the entire acoustic space was reduced around the resonance frequencies. Furthermore, the limit of the control effect are considered within the proposed system.

著者

松岡 太一

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.83, no.854, pp.17-00292-17-00292, 2017 (Released:2017-10-25)

参考文献数

22

被引用文献数

3

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In this paper author proposed a unique vibration suppression device that has variable inertia mass using continuously variable transmission (CVT) in order to obtain vibration isolation when a harmonic frequency was coincided with an anti-resonance frequency of 1DOF system. The device complies a ball screw mechanism, a flywheel, servo motors and CVT. The CVT is composed of toroidal wheels and power transmission wheels. The device has a small inertia force when an attitude angle of the power transmission is low by the servo motor as depending on a contact radius between two half toroidal wheels, on the other hand the large inertia force under high angle, so variable inertia force which acts as series inertia mass can be controlled continuously. The trial device was manufactured and the resisting force characteristics were measured. Theory of the variable inertia force was introduced, and compared with the experimental results. In order to confirm vibration control, an optimized inertia mass which always adjusts to anti-resonance frequency was determined in case of 1DOF system with the device, frequency response tests were carried out by using a shaking table, and experimental results were compared with calculated ones. Finally, the theory of resisting force and effects of vibration suppression were confirmed.

著者

松田 聡一郎 松浦 大輔 菅原 雄介 武田 行生

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.854, pp.17-00282-17-00282, 2017 (Released:2017-10-25)

参考文献数

17

被引用文献数

2

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In order to improve living space for stable walks by elderly people, this paper discussed assessment of living space with unique-shaped support objects. Four evaluation indices expressing capability of balance recovery corresponding to the support object were derived based on directionality of generative force by human's upper extremity and directionality of reaction force depending on surface shapes of the objects. Experiments were carried out to (1) obtain the parameters necessary to calculate the proposed indices and (2) carry out organoleptic evaluation of the support objects. Compared to the results obtained in these experiments (1) and (2), effects of the proposed indices were discussed, and an effective index among the four for evaluating the effect of the support objects was clarified. Assessment of a support object using the index was shown as an example.

著者

田井 浩一 佐藤 邦彦 前田 栄一

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.83, no.854, pp.17-00259-17-00259, 2017 (Released:2017-10-25)

参考文献数

9

被引用文献数

1

---

Response spectrum analysis method is widely used for the seismic design of equipment and piping systems of nuclear power plant, or other industrial facilities. Some of the equipment and piping systems are multiply supported with plural floors, or several different points. In these cases, conservative design methods, such as uniform response spectrum (URS) method that envelopes all of the individual response spectra, or independent support motion (ISM) method are commonly accepted. These design methods are not practical, but often mislead to design with unnecessary conservatism. This paper presents the practical seismic analysis methodologies considering the correlation coefficients of seismic responses with multi-directional excitations, which is extended to apply the correlations between modal responses and between support motions, called cross-oscillator, cross-floor response spectrum by Asfura, A. and Kiureghian, A,D., and numerical examples are also presented to examine the validity for the seismic analysis method of multiply supported secondary systems, with simultaneous three directional excitations of each X, Y, Z axis.

著者

水野 毅 Asief JAVED 石野 裕二 髙﨑 正也

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.854, pp.17-00217-17-00217, 2017 (Released:2017-10-25)

参考文献数

19

被引用文献数

2

---

A switching stiffness control and a modified variable stiffness control were applied to reduce vibration in the lateral directions in active magnetic suspension system with electromagnets operated in the differential mode. The magnetic suspension system using the attractive force between magnetized bodies is inherently unstable in the normal direction so that feedback control is necessary to achieve stable suspension. In contrast, it is usually stable in the lateral directions because of the edge effects in the magnetic circuits. However, damping in the lateral directions is poor so that vibration is easily induced. In this work, a switching stiffness control was applied to attenuate such vibration. The effectiveness of the switching stiffness control was confirmed experimentally. In addition, a modified control method that varies stiffness continuously was proposed to overcome problems occurring in switching. The efficacy of the modified control method was also confirmed experimentally.

著者

福田 拓生 坂口 聡範 滝本 隆 潮 俊光

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.17-00207-17-00207, 2017 (Released:2017-10-25)

参考文献数

22

---

The quadrotors are useful for periodic inspections of tunnels and bridges. However, the conventional quadrotor has a problem such that it is impossible to control the rotational motion and the translational motion independently. Therefore, if the camera is attached on the bottom of the quadrotor, it is difficult to observe its upward direction. In this paper, we develop a novel quadrotor that has a parallel link to tilt itself. By increasing one degree of freedom of the quadrotor, we resolve the problems described above. And we derive a model of the developed quadrotor. Then, we consider a PID controller for the stabilization of the quadrotor at a specified hovering state. We derive gain parameters of the PID controller by which the controlled quadrotor is stabilized.

著者

柏崎 翔 涌井 伸二

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.854, pp.17-00189-17-00189, 2017 (Released:2017-10-25)

参考文献数

24

被引用文献数

7

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Pneumatic anti-vibration apparatus (AVA) has been used for suppressing the vibration from the floor. Compressed air produced by the air compressor is supplied to air spring, which is used as an actuator in AVA. This paper considers the suppression of flow disturbance, which is caused by pressure variation of compressed air. Based on the internal model principle, the suppression of vibration of AVA due to flow disturbance has been confirmed by using Central Pattern Generator (CPG) in parallel with a displacement controller. In biological study, CPG in bodies playing a significant role in the walking have been learned. Moreover, mathematical models of CPG have been reported, and some researchers have been studying about walking of biped-robots by using CPG to generate desired value. On the other hand, this paper proposes asymmetric CPG as new model for further vibration suppression, compared with the symmetric CPG which is the conventional model. This new model introduces asymmetry by changing its parameters into different values in order to improve reproducibility of waveform which shows the variation of supplied air pressure. Validity of the proposed model is presented by experimental result of AVA. The effectiveness is shown by analyzing and comparing the results of experiment and simulation of symmetric and asymmetric CPGs.

著者

吉武 裕 安部 晃 村上 心 梶原 修平 古川 隼人 坂本 竜二郎

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.854, pp.17-00164-17-00164, 2017 (Released:2017-10-25)

参考文献数

9

被引用文献数

1

---

This paper deals with the vibration quenching problem of the one-degree-of-freedom system with a limited power supply. This system is forced by centrifugal force of rotating unbalance, and the system is quenched using a Hula-Hoop and a motor to assist the rotation of Hula-Hoop. The entrainment region, the amount of vibration quenching, and the energy consumptions of the system are studied from the approximate analysis using the averaging method, the numerical integration analysis, and the experiment. Following was made clear: (1) When the unbalance is large, the entrainment region of the voltage of the assistant motor is large. On the other hand, when the unbalance is small, the entrainment region becomes narrow. (2) When the unbalance is large, by setting the voltage of the assist motor to a value smaller than the optimum value for vibration control, within the range that satisfies the allowable vibration amplitude level, the increase amount of the energy consumption becomes low. (3) The approximate solutions obtained by the averaging method are in good agreement with those obtained by the numerical integration method, and the characteristics of these results coincide with those of the results obtained by experiment.

著者

金生 翔太 橋本 雅文 余田 侑仁 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.17-00138-17-00138, 2017 (Released:2017-10-25)

参考文献数

26

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This paper presents a laser-based tracking (estimation of pose and size) of moving objects using multiple mobile robots in Global-navigation-satellite-system (GNSS)-denied environments. Each robot is equipped with a multilayer laser scanner and detects moving objects, such as people, cars, and bicycles, in its own laser-scanned images by applying an occupancy-grid-based method. It then sends measurement information related to the moving objects to a central server. The central server estimates the objects’ poses (positions and velocities) and sizes from the measurement information using Bayesian filter. In this cooperative-tracking method, the nearby robots always share their tracking information, allowing tracking of invisible or partially visible objects. To perform a reliable cooperative tracking, robots have to correctly identify their relative pose. To do so in GNSS-denied environments, the relative pose is estimated by scan matching using laser measurements captured by both sensor nodes. Such cooperative scan matching is performed by 4-points-congruent-sets (4PCS)-matching-based coarse registration and Iterative-closest-point (ICP)-based fine registration methods. The experimental results of tracking a car, a motorcycle, and a pedestrian with two robots in an outdoor GNSS-denied environment validate the proposed method.

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.854, pp.17-00095-17-00095, 2017 (Released:2017-10-25)

参考文献数

14

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We propose image processing method for road white-line detection using brightness gradient direction of edges. Many methods for white-line detection have been proposed for standardized roads. These methods use model fitting for the detection of edges on white-line contour. So it is difficult to apply these methods to non-standardized roads for which modeling is difficult. To expand the scope of white-line detection to common roads in the future, it is necessary to achieve processing without models. Clustering based on position proximity of edges is one approach. However, there is concern about degrading noise reduction that has so far been done by model fitting. In this study, we developed an edge clustering method that utilizes the characteristics of edges on white-line contours; proximity of position as well as proximity of brightness gradient direction. In the proposed method, edges are first clustered based on proximity of gradient direction. And for each cluster, edges are again clustered based on proximity of position. Edge filter bank is specially designed for the first clustering and the effectiveness compared to conventional filter bank is explained. By applying the method to the images taken by on-board camera, we demonstrate that white-line detection that can apply to diverse road environments but is hardly affected by noise can be realized.

著者

早坂 良 大村 高弘

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.17-00180-17-00180, 2017 (Released:2017-10-25)

参考文献数

9

---

We have investigated the sedimentation phenomenon in a colloidal dispersion composed of spherical ferromagnetic particles using Brownian dynamics simulations. We have attempted to clarify the conditions under which all particles settle down and a thin film is formed, by varying the applied magnetic field, magnetic force between particles, mass density, and temperature of the solution. The particle concentration was set so that the average inter-particle distance was 2.5 times the particle diameter. The main results obtained are summarized as follows. When the mass density is increased, the sedimentation rate increases due to the influence of gravity. The sediment is deposited at the bottom layer immediately after being dropped, and the particles display a stronger tendency to settle down at the bottom layer. However, as the magnetic force between the particles increases, the bonding between the particles becomes strong and clusters are formed, which makes it difficult to obtain the desired thin film in which all particles precipitate at the bottom layer and exist separately. Even in such a situation where the influence of the applied magnetic field is dominant, a thin film can be obtained if the magnetic moment of the particle is strongly restrained in the direction of the magnetic field, thus preventing the formation of clusters. In addition, when the density ratio is as large as 30 as is in this case, a planar cluster may be formed in the lowermost layer even when all the particles have settled down. On the other hand, if the temperature of the liquid is too low, the clusters remain intact without collapsing because of the low random force. As a result, the desired thin film cannot be obtained. However, there is a limitation where in the number of conditions under which the thin film formation occurs does not increase when the random force value exceeds a certain level.

著者

鈴木 博幸

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.101, no.954, pp.367-370, 1998-05-05 (Released:2017-06-21)