著者

平田 洸介 桝井 文人 大谷 拡夢 柳 等 プタンシスキ ミハウ

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

巻号頁・発行日

vol.2015, pp."D-5-1"-"D-5-6", 2015-10-30

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This paper reports on the analysis of the characteristics for each position in curling based on shot-scores. We computed average shot-scores for each position using 14 game information about college-top level teams, and analyzed the correlation between the differences of average shot-scores and the differences of final game scores. The results show that strong correlations appeared on the results of the lead positions and the fourth position, and no correlation for second position and third relates to the game progress. There is possibility to predict game results and game progress based on short-score for each position.

著者

太田 憲 梅垣 浩二 室伏 広治 羅 志偉

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

巻号頁・発行日

vol.2010, pp.319-324, 2010-11-02

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The motions of a hammer are commonly regarded as a circular movement which a hammer undergoes around a turning human body. The distance of a throw depends on the speed of the hammer and the angle of its trajectory at the instant of release. The speed of the hammer increases gradually during preliminary winds and turns. During each turn the hammer rises up toward the high point of the trajectory and passes through the low point. Our interest in this study was to understand the mechanism of acceleration of the hammer in terms of parametrical excitation. The motions of hammer were analyzed to examine our theory using double pendulum model.

著者

韓 露 中楯 浩康 青村 茂 張 月琳 松田 雅弘 小山 貴之

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

巻号頁・発行日

vol.2015, pp."C-11-1"-"C-11-6", 2015-10-30

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In this study, Judo and American Football (AF) are spotlighted as typical physical contact sports that concussion or subdural hematoma could happen during a play. In Judo, "waza" to cause a risk to hit a head on a tatami were performed by Judo players and recorded by VICON system and the motions were reconstructed by MADYMO by using VICON data and kinetic data and hit part were generated. In Americal football, the moment of concussion was reconstructed by MADYMO by observing the accident data in real play recorded on a video and kinetic data and hit pat were generated. In both cases the strain and stress of the brain tissue were calculated in detail by the FE human head model and injury risk was predicted, respectively.

著者

青木 克巳 岡永 博夫 長瀬 二郎

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

巻号頁・発行日

vol.2013, pp._241-1_-_241-10_, 2013

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In this report, aerodynamic characteristic such as lift and drag of official rubber-balls used in the game of the baseball are studied experimentally. And the aerodynamic characteristic of these rubber-ball is compared and is examined with the aerodynamic characteristic of smooth sphere and sphere with dimple and the Major League ball. In addition, the aerodynamic characteristic for seam angle and spin rate ratio ratioα (=V/U, V: peripheral velocity of test balls, U: flow velocity)is also clarified. And, the flow pattern around the test balls are visualized by the spark tracing method. Following conclusions were got from these results. (1) The dimpled rubber-ball has a critical region where the drag coefficient decreases in the same way as the smooth surface balls. (2)Depending on the surface structure of test balls, the aerodynamic characteristics differ significantly. When dimples are added to the balls with seams, the critical region moves toward the lower Reynolds number side, but the minimum drag coefficient increases. (3)About the rubber-ball and Major League ball, C_D shows the almost same values without rotation. However at the rotational state, C_D of the Rubber-ball is lower than that of the Major League ball . (4)The values of C_D take different values depending on type A〜E and become large as α increases. The values of C_L stand in a same line which rises as α increase.

著者

平野 孝典

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

巻号頁・発行日

vol.2019, pp.B-8, 2019

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<p>Archery has many competitors around the world, but new materials are used for the parts of bows as technology develops in recent years. Due to the diversification of new materials, there are increasing number of unexplained areas of archery performance. One of them is the arrow feather (Vain). Vain is roughly divided into rotary and non-rotary types. Currently, the rotary type is mainly the drag type, but if a lift type rotary vane can be developed, the rotational force can be obtained with a low drag, so it is considered that a vane with better performance can be achieved. If we can clarify the characteristics and common points of Vain that lead to higher scores, we can expect to develop new vanes. In wind tunnel experiments, using a jig with an arrow model, measurement and analysis were performed on the rotational performance and convergence performance of the arrow model at a uniform flow velocity of 20 m/s (1/3 of the actual arrow speed). To evaluate the performance of Vane, the rotational performance was evaluated by the number of revolutions for each of the non-converging motion (at rest) and the converging motion (vibration), and the convergence performance was evaluated by the time until convergence of vibration. In the performance evaluation of off-the-shelf products, it became clear that rotary vanes can be further classified into those with top pitches and those that do not, and those with many users worldwide do not have top pitches.</p>

著者

川副 嘉彦 中川 慎理

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

巻号頁・発行日

vol.2010, pp.147-152, 2010

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The previous paper of the authors made clear the mechanism of top-spin performance in tennis and its improvement by lubrication of strings according to the high speed video analysis. As the main strings stretch and slide side ways more, the ball is given more spin due to restoring force parallel to the string face when the main strings spring back and the ball is released from the strings. Since the notches of strings decrease spin rate, the lubricant materials are effective to the notched strings and the spin rate of newly strung tennis racket without notches is much larger than that of used racket with notches. Furthermore, it showed that the more spin results in the reduction of shock vibrations of the wrist joint during impact. There are several strings now on the market that are designed explicitly to take advantage of the slippery string mechanism for top spin improvement. This paper showed the spin behavior of the ball and the revolutionary flat strings during oblique impact in the laboratory by the high speed video analysis and recognized that flat strings are more slippery and generate more spin than the conventional strings.

著者

池上 洋介 李 昌憲 ブレスデル エレン 中村 仁彦 鮎澤 光 柏木 匠 久保田 奏 吉松 昭洋 中村 優介 井深 祐輝 石川 淳一 洪 舜傑

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

巻号頁・発行日

vol.2011, pp.303-308, 2011

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In this paper, human muscle tension estimation based on robotics dynamics and its visualization technique was reported. Human muscle tension estimation was obtained by kinematics and dynamics using optical motion caputure data, force plate data and EMG signals. The environment for the motion capture and the calculation flow was explained. The visualization technique was explained. Tai chi, tap dance and drum motion was analyzed, respectively. The obtained findings of the experts' motion technique were reported.

著者

梅垣 浩二 室伏 広治 太田 憲 桜井 伸二

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

巻号頁・発行日

vol.2012, pp.265-270, 2012

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An increase or decrease of the hammer head mechanical energy was caused by an accumulation of the positive or negative handle power which was the product of wire tensile force and handle velocity in the wire length direction. During single support phase a decrease of the wire tensile force was reduced by a fictitious force caused by handle relative pulling acceleration and relative leading velocity to thrower's center of mass (C.M.). Ground reaction force was resulted from maintaining balance with wire tensile force, hammer head centrifugal force, hammer handle coriolis force, and so on under rotational coordinate system. During double support phase handle relative pushing acceleration and relative drawing velocity to thrower's C.M. caused a fictitious force which make balance with the addition of wire tensile force and hammer head rotational force in the wire length direction and with hammer head rotational force in the horizontal direction perpendicular to wire, so that thrower pushed the ground on his/her feet.

著者

吉田 瑞人 岩田 佳雄 三枝 宏 小松﨑 俊彦

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

巻号頁・発行日

vol.2018, pp.C-5, 2018

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<p>We prepared 7 cavity-backed disk plates which were same to baseline calibration plate used in COR test. Their membrane thickness increased by 0.2mm from 1.8mm to 3.0mm. CT(Characteristic Time)s were tested by a pendulum test instrument and CORs were measured through COR test using an air gun. The relation between CT and COR agreed with their linear characteristic described in "Technical Description of the Pendulum Test" by R&A and USGA for the thickness of 2.6mm or more. On the other hand, COR was constant and CT only increased for 2.4mm or less. Finally estimation of CT of the plates was simulated. As a result, we show that it is possible.</p>

著者

高畑 智之 渡辺 諒 グェン ミンジューン 高橋 英俊 松本 潔 下山 勲

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

巻号頁・発行日

vol.2015, pp._C-8-1_-_C-8-4_, 2015

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We propose a precise altitude change measurement method by sensor fusion of sensitive pressure change sensor, which is based on MEMS differential pressure sensor, and commonly used pressure sensor. Precision of the fused pressure measurement was as high as 0.1 Pa. We measured the pressure change during walking up stairs.

著者

大西 熙 室巻 孝郎 須田 敦 川田 昌克 鈴木 立人

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

巻号頁・発行日

vol.2017, pp.A-13, 2017

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<p>Elderly people and persons with disabilities are likey to be obstructed activities in daily life by deteriorating of sit-to-stand ability. The population of elderly people are increasing rapidly in Japan, and the support of sit-to-stand is hard work for caregivers, who are likely suffering back pain. The purpose of this study is to develop a sit-to-stand assist chair, which assists sit-to-stand movement by lifting a seat. In this report, we focus on the trajectory of a buttock in sit-to-stand, and report results of experiments on three foot height conditions. The buttock's trajectories had a S shape on the high foot height, which was the hardest condition, and was changed to an arc shape on the low foot height, which was the easiest in this study. In the case that the buttock's trajectory gets close to the arc shape, the hardness of the standing motion might be reduced. The velocity of buttock movement varies with the person's height.</p>

著者

前田 正登

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

巻号頁・発行日

vol.2016, pp.B-11, 2016

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<p>In this study, throwing experiments were conducted with the participation of six javelin throwers using a wooden javelin produced to conform to the current regulations for javelin throw competitions and a normal javelin made by duralumin. In the experiments, the wooden javelin and duralumin javelin were thrown and the following release parameters were measured: initial velocity, release height, release angle, attitude angle, and angle of attack). The distances of the throws were measured and the effects of the release parameters were assessed. As a result, it was found that the thrown distance of the wooden javelin was slightly shorter than that of the duralumin javelin, but the difference was not significant. Similarly, no significant difference was observed in each release parameter. The standard deviation of each release parameter was relatively large, and individual differences between the throwers were considered to be one of the causes.</p>

著者

中野 宏二郎 橋本 修宏 吉田 準史

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

巻号頁・発行日

vol.2016, pp.C-26, 2016

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<p>In this paper, we investigated energy distribution of a sports bicycle for evaluating the acceleration performance quantitatively. As the input force for measurement of the performance, constant weight was put on one side pedal of the bicycle positioned on a running roller, and the rotational speed of the wheel was measured under various conditions. The acceleration performance was then calculated by dividing the increased rotating rolling energy by the input energy. The result shows that almost 60% of the input energy was used for the acceleration of the bicycle. In addition, we also investigated influence of the wheel weight (moment of inertia) and air pressure of the tire on the performance. As the results, the performance was increased about 5% by the 30% reduction of the inertia. On the other hand, the performance was observed to decrease about 4% by the 30% reduction of the tire pressure. From these results, we could obtain the influence of the wheel and the tire characteristics on the acceleration performance of the sports bicycle quantitatively.</p>

著者

伊藤 慎一郎 鎌田 真輝 浅井 武 瀬尾 和哉

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

巻号頁・発行日

vol.2011, pp.23-26, 2011

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The configuration of soccer balls has closely approached a perfect round shape by not only reducing a number of panels but also by eliminating roughness of the panel joints by thermal bonding process recently. Therefore, in a non-rotating or low-rotating moving shot, a soccer ball drops and curves by the change of wake flow, which is called a knuckle ball effect. It is said that the cause of the swerving ball on no rotating shoot of the soccer ball depends on the outbreak of the vortex occurred in the wake. However, it is not grasped the timing among the vortex outbreak and the swerving of balls. In this study, the velocity fluctuation of the ball wake was measured with hot wire probe and the oscillation of the ball was measured with three components load cell. And also the asymmetric configuration of the ball panel against moving direction was investigated as a factor to bring unexpected change of the ball orbit. The results show that the position change of the tail of vortex ring affects the swerving of the balls and that the low-rotating ball changes its face against the moving direction and it produces irregular lateral force.

著者

小池 関也 見邨 康平

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

巻号頁・発行日

vol.2015, pp."A-24-1"-"A-24-10", 2015-10-30

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The purpose of this study was to quantify the contribution of the whole-body joint torques to the generation of evaluation values during baseball batting motion, such as bat head speed and angular motion of the lower trunk in consideration of the joint torque generating mode. The whole-body segments and bat were modeled as a system of sixteen-rigid linked segments, and constraint axes of the elbow, wrist, knee and ankle joints were modeled with anatomical constraint equations in order to consider the degree of freedom (DOF) of the joint. Each hand was considered to be connected with the bat through zero DOF joint. The equation of motion with respect to the whole-body and bat was obtained by considering modelling errors, such as, residual joint force and moment, and fluctuation of segment's length. The dynamic contributions of the joint moments, motion dependent term and gravity term to the bat head speed and angular motion of the lower trunk were derived from the equation of motion for the system. Furthermore, the joint torque was divided into two components, such as eccentric torque component, which shows negative sign of its torque power, and concentric torque component, which shows positive sign of its torque power. The results obtained in this study showed that 1) motion dependent term was the great contributor to the generation of bat head speed and 2) major contributors to the generation of the bat head speed, such as concentric components of knob-side shoulder abduction torque and torso joint rotational torque were quantified by considering main generating factor of motion dependent term.

著者

東海林 創 橋本 眞也 櫻井 俊明 日比野 郁夫

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

巻号頁・発行日

vol.2013, pp."304-1"-"304-5", 2013-11-01

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This paper describes the motion analysis of the Japanese bow made from carbon fibers with the linen string for archery. The final target of this study is to establish the realistic relationship between human body and the bow with the string in giving instruction and to propose a suitable text book for players to keep healthy. In this case, a vibration characteristic of the bow with the string is noticed due to experiments and calculations by the Rigid Motion Analysis. The calculation model consists of rigid bodies and rotational springs. When the string of the bow is drawn and released, displacements and vibration characteristics of the upper and lower of the bow are measured by video-camera and calculated by computer. A good coloration between experiments and calculations is taken. It is considered in the next step to make human body models with some kinds of the skeleton.