著者

伊藤 史斗 長谷 和徳 内田 和男

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.19-00191, (Released:2019-09-11)

参考文献数

15

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The frame stiffness in a racing bicycle might influence not only toughness as the frame structure but also performance of an athlete. The purpose of this study is to clarify biodynamic relations between the frame stiffness in a racing bicycle and the physical loads of an athlete by using a forward dynamics simulation model. The human body structure was represented by the 13-rigid-links and 23-degrees-of-freedom model. Based on the theory of multibody dynamics, the frame structure was expressed by combination of 12 rigid pipes, and the frame stiffness was modeled by rotational springs at the connecting joint between the rigid pipes. Spring coefficients were changed according to the thickness of the frame pipes. The pedaling load from the crank was computed by the angular velocity and angular acceleration of the crank. Moreover, the driving force in the bicycle was additionally defined to consider the influence of the frame weight on the human joint load. The human body model was driven by the joint toques to minimize the cost function consisting of the joint loads in the human body and the driving force in the bicycle, and also to keep desired angular velocity of the crank. Validity of the simulation was evaluated by comparing the joint angles and torques with the measured ones. As for the result, the larger stiffness of the frame resulted in smaller the joint loads in the human body, and optimal stiffness would be determined by the balance between the joint loads in the human body and the driving force in the bicycle.

著者

長谷 和徳 西口 純也 山崎 信寿

出版者

バイオメカニズム学会

雑誌

バイオメカニズム

巻号頁・発行日

vol.15, pp.187-198, 2000

被引用文献数

20 6

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Many computer simulation studies of human bipedal walking have been conducted in the field of biomechanics. The musculo-skeletal systems in previous models, however, have been simplified two-dimensionally, and theoretical methods in robotics have been applied for the motor control mechanisms. The purpose of this study was to develop a more precise simulation model of human walking in order to improve the practicability of the simulation method. As a result, a model was created in which the musculo-skeletal system of the entire body is modeled three-dimensionally, and a mechanism for motor control was constructed by a neuronal system model having a hierarchical structure. The inertial properties of the entire human body were represented by a three-dimensional , 14-rigid-link system. These links include the feet, calves, thighs, pelvis, lower lumbar region, upper lumbar region, thorax, upper arms, and forearms. The body's dynamic model is driven by 42 muscles for the entire body. The arrangement of each muscle was represented as a series of line segments, the direction of which changes according to joint angle. Energy consumption, including heat production, in the muscle was calculated from the generating tension. The hierarchical neuronal system includes three levels. First, at the highest level, there is a neuronal system corresponding to the higher center level. The function of adjusting changes in walking pattern is assumed to exist at this system level. The model was expressed by a computational multi-layered neural network. Second, at the middle level , there is a neuronal system corresponding to the spinal cord level. This neuronal system, representing a rhythm-generation mechanism, was modeled as a network system consisting of neural oscillators. They generate the neuronal stimulus combined for each degree of freedom by receiving nonspecific stimulus from the higher center and feedback signals from the somatic senses. Each neural oscillator is mathematically expressed by two differential equations. Third, at the lowest level, there is a neuronal system corresponding to the peripheral level. The neuronal system divides the combined neuronal stimulus from the neural oscillator into the neuronal stimulus to each muscle. The model is mathematically represented as an optimization problem. The simulated walking pattern was continuous and stable. The walking pattern closely agrees with actual human walking in terms not only of joint movement but also of muscle activities and energy consumption. In order to investigate the effects of higher center system functioning in adjusting walking patterns, we compared a walking pattern generated by a model incorporating a higher center system with the patterns obtained from a model without the higher center system, in terms of robustness of mechanical perturbation. Although the model without the higher center system could not stabilize its walking pattern and finally fell down, the model with the higher center system could perform continuous walking without falling down.

著者

伊藤 史斗 内田 和男 長谷 和徳

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 2017 (ISSN:24329509)

巻号頁・発行日

pp.A-9, 2017 (Released:2018-05-25)

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There are many studies for bicycles and pedaling; however, most of the pedaling studies are conducted based on experiments, such as inverse dynamics method. The purpose of this study is to develop a forward dynamics model of pedaling to generate pedaling motion on computer without experimental data. The proposed model was used proportional-derivative (PD) control for joint driving torque and the referred joint angles were optimized by genetic algorithms. Cost function of optimization was defined as minimum of the muscle load and differences between the objective crank angular velocity and that of the simulation. Joint torques and pedal forces was obtained from the simulation and was compared with the actual experimental data. Simulation results were tended to vibrate compared with the actual experimental data. In addition, magnitude of the cost function was investigated when changing saddle height as 0.700, 0.725, 0.750, 0.775 and 0.800 [m]. As a result, the cost function decreased as the saddle height became higher, and the cos function was minimum when the saddle height was 0.775[m].

著者

福住 敦 竹原 昭一郎 長谷 和徳 吉村 卓也

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:18848354)

巻号頁・発行日

vol.77, no.777, pp.1686-1695, 2011 (Released:2011-05-25)

参考文献数

16

被引用文献数

1 3

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In this study, the vertical jump is examined as a basic study of jump. And we examine the influence of each muscle of the human body in vertical jump. The human body is modeled as four rigid bodies and analyzed in detail by using the model that includes muscles of the leg. In this research, the mechanism of jump is discussed by using numerical model to which the concept of multibody dynamics and biomechanics is adapted. We performed the experiment of jump and observe the feature behavior of vertical jump. Experimental results show that the angle of each body becomes vertical for ground and the change of the foot angle is small. Then we perform the numerical simulation referring to this experimental data. In order to reduce the amount of calculation, we calculate muscular activity level by correlating it with fewer parameters. We discuss which muscles are necessary for vertical jump. It is found that vasti exerts the biggest power and gluteus maximus has the highest state of normalized muscle activity.

著者

長谷 和徳

出版者

一般社団法人 日本人間工学会

雑誌

人間工学 (ISSN:05494974)

巻号頁・発行日

vol.50, no.5, pp.256-264, 2014-10-15 (Released:2015-07-25)

参考文献数

23

被引用文献数

1

著者

伊藤 史斗 長谷 和徳 内田 和男

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.85, no.878, pp.19-00191, 2019 (Released:2019-10-25)

参考文献数

15

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The frame stiffness in a racing bicycle might influence not only toughness as the frame structure but also performance of an athlete. The purpose of this study is to clarify biodynamic relations between the frame stiffness in a racing bicycle and the physical loads of an athlete by using a forward dynamics simulation model. The human body structure was represented by the 13-rigid-links and 23-degrees-of-freedom model. Based on the theory of multibody dynamics, the frame structure was expressed by combination of 12 rigid pipes, and the frame stiffness was modeled by rotational springs at the connecting joint between the rigid pipes. Spring coefficients were changed according to the thickness of the frame pipes. The pedaling load from the crank was computed by the angular velocity and angular acceleration of the crank. Moreover, the driving force in the bicycle was additionally defined to consider the influence of the frame weight on the human joint load. The human body model was driven by the joint toques to minimize the cost function consisting of the joint loads in the human body and the driving force in the bicycle, and also to keep desired angular velocity of the crank. Validity of the simulation was evaluated by comparing the joint angles and torques with the measured ones. As for the result, the larger stiffness of the frame resulted in smaller the joint loads in the human body, and optimal stiffness would be determined by the balance between the joint loads in the human body and the driving force in the bicycle.

著者

長谷 和徳 梶 大介 松山 幸弘

出版者

一般社団法人 日本人間工学会

雑誌

人間工学 = The Japanese journal of ergonomics (ISSN:05494974)

巻号頁・発行日

vol.46, no.1, pp.61-67, 2010-02-15

参考文献数

7

被引用文献数

2

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我々は,草鞋の機能を模擬したとされる足部装具が歩行運動や立位姿勢に与える影響を明らかにするため,光学式運動計測装置,床反力計などを用いた運動力学計測を以前において行った.本研究ではさらに,足部装具の装着方法を変化させ,筋骨格モデルや足圧分布計などを用いて,より詳細に足部装具,足指の運動,歩行の関係を明らかにすることを目的とする.実験では被験者10名に対して,第1・2指間刺激,第2-5指拘束,全指拘束の3種類の装着法にて足部装具を装着させ,歩行動作と立位姿勢の運動力学計測を行った.また別途,足圧分布計上での歩行実験を行った.第1・2指間刺激の方法では足指の屈曲位,足指間距離の増大などが見られ,足関節まわりの筋活動が増大した.他の装着法でもそれに応じた足部形状の変化,歩容の変化が見られ,これらの結果に基づき本装具が身体動作に与える効果について議論した.

著者

中山 淳 大日方 五郎 長谷 和徳

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学術講演会・セミナー講演論文集

巻号頁・発行日

vol.2004, no.17, pp.323-324, 2005-01-21