著者

太田 憲 梅垣 浩二 室伏 広治 小宮根 文子 桜井 伸二

出版者

一般社団法人 日本機械学会

雑誌

ジョイント・シンポジウム講演論文集:スポーツ工学シンポジウム:シンポジウム:ヒューマン・ダイナミックス

巻号頁・発行日

vol.2008, pp.270-274, 2008

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Dynamics-based force sensor using accelerometers which measures forces and joint torques has been developed. In this study we have applied this method to hammer throw training aid integrating small sensors, signal processing, short-range wireless transmission, data-logger and biofeedback training system. The purpose of this study was to establish methods for the measuring of rotational movement and the biofeedback training system for hammer throwers. Microelectromechanical systems accelerometers were chosen as the sensor platform capable of because they are noninvasive miniaturized devices and have wide bandwidth. In this system, a wireless data-logger was developed as a wearable device to replace cables and reduce constraint caused by wearing cables. The transmitted data were given as biofeedback information over a speaker through signal processing and voltage to frequency conversion.

著者

平岡 史博 穂苅 真樹 渡辺 嘉二郎

出版者

一般社団法人 日本機械学会

雑誌

ジョイント・シンポジウム講演論文集:スポーツ工学シンポジウム:シンポジウム:ヒューマン・ダイナミックス

巻号頁・発行日

vol.2003, pp.40-42, 2003

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In budou, effective hit is chiefly judged to the opponent by umpire's eyes. The shock speed of the tool going up as athlete's skill improved and judging only by umpire's eyes became difficult. As a result, the possibility of causing the misjudgment has risen. If the judging standard can be quantified, and there is a system that can easily judge effective hit, it can use not only the misjudgment prevention but also to practice shock, and is useful for a further improvement of the skill. The judgment method of assuming sports chanbara to be an example in the main discourse and using the gyro sensor and the system that had achieved it were constructed. Moreover, the validity of the effective hit judgment system that achieved it was verified by the experiment.

著者

永見 智行 小宮山 悟 彼末 一之 諸星 潤 大室 康平 茶川 剛史 勝亦 陽一 氏原 洋輔 子安 大士 前川 仁

出版者

一般社団法人 日本機械学会

雑誌

ジョイント・シンポジウム講演論文集:スポーツ工学シンポジウム:シンポジウム:ヒューマン・ダイナミックス

巻号頁・発行日

vol.2008, pp.108-111, 2008

被引用文献数

1 1

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The authors have recently developed a system for analyzing the spin on a baseball (Koseki et al., 2007). In the present study we analyzed the spin pitched by a professional pitcher. He pitched eight different pitches, each twice, from official pitching mound. The image of ball in the period from just before to 500 ms after the ball release was taken with a high speed video camera at 1000 fps. English alphabets E, M, A, and I were marked on the ball for image processing. Feature points from the image stream were assembled into a set of linear equations that represents orientation change between consecutive two frames by rotation matrix R, and the direction of spin axis and spin rate were obtained. Both values varied considerably depending on pitches. The recording of spin was suggested to be valuable for training if the data could be combined with those of motion analysis.

著者

渡邉 敬人 藤原 聖司 後藤 裕太 岩原 光男 長松 昭男 新井 和吉 寺西 幸弘 長尾 裕史

出版者

日本機械学会

雑誌

ジョイント・シンポジウム講演論文集:スポーツ工学シンポジウム:シンポジウム:ヒューマン・ダイナミックス

巻号頁・発行日

vol.2006, pp.104-109, 2006

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Recently, baseball bats that have kinds of characters have been marketed due to advances in the materials and structure of modern baseball bats. One of remarkable point is a sweet spot in bats. But a sweet spot is sensuous and its point is laxness. So the reason why a sweet spot is approved is researched in this study. First of all, the first node, the second node and center of impact were measured. Next, the ball was made to collide with them and the repulsion coefficients were measured, and compared.

著者

秦 秀敏 宇津野 秀夫 松久 寛

出版者

一般社団法人 日本機械学会

雑誌

ジョイント・シンポジウム講演論文集:スポーツ工学シンポジウム:シンポジウム:ヒューマン・ダイナミックス

巻号頁・発行日

vol.2004, pp.89-94, 2004

被引用文献数

1

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Impact problem between a bat and a ball was studied using vibration modal analysis. Initial kinetic energy of the ball and the bat before the collision is transmitted to their vibration energies and their rigid body kinetic energies. The rebound speed of the ball is theoretically calculated and was measured in the experiments for slow speed impact condition. There was a good agreement between the calculation and experiment. The rebound speed of the ball was also calculated for the high speed impact condition. When the bat hits the ball with relatively high speed, higher order vibration modes appear. Therefore it is possible to increase the rebound speed of the ball by changing the design of the bat, such that the higher order modes are suppressed.

著者

小鮒 幸洋 藤波 努

出版者

一般社団法人日本機械学会

雑誌

ジョイント・シンポジウム講演論文集:スポーツ工学シンポジウム:シンポジウム:ヒューマン・ダイナミックス

巻号頁・発行日

vol.2006, pp.213-215, 2006

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It is widely accepted that stability of bodily movement is a key to studying skills. We can however not explain what the stability is. We took as an example of skills the walking on stilts and investigated how the bodily movement of the experienced are different from those of the inexperienced. We analyzed the difference in terms of stability of periodic movements. As a result, it showed significant differences between the experienced and the inexperienced.