著者

熊本 博光 西原 修 平岡 敏洋

出版者

公益社団法人精密工学会

雑誌

精密工学会誌 (ISSN:09120289)

巻号頁・発行日

vol.68, no.5, pp.681-686, 2002-05-05

被引用文献数

2 2

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This paper considers salt water fishing tackles consisting of line, hook, bar float, primary sinker and secondary sinkers. The line with the sinkers and the hook are modeled by a multi-link system connected with the float. A new algorithm is proposed to calculate acceleration terms satisfying Newtonian kinematical equations. The computational requirement varies only linearly with the number of links because the algorithm is based on a sweep-out operation on a threefold diagonal matrix with a simple structure. A comparison is made with a well-known Featherstone algorithm that is based on articulated body inertias. Animation results with 22 links subjected to tidal flow and wave produce typical tackle behaviors consistent with expert experience. The animation is useful for design of tackles and discrimination drills of fish hits.

著者

熊本 博光 西原 修 平岡 敏洋

出版者

公益社団法人 精密工学会

雑誌

精密工学会誌 (ISSN:09120289)

巻号頁・発行日

vol.68, no.5, pp.681-686, 2002-05-05 (Released:2009-04-10)

参考文献数

6

被引用文献数

1 2

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This paper considers salt water fishing tackles consisting of line, hook, bar float, primary sinker and secondary sinkers. The line with the sinkers and the hook are modeled by a multilink system connected with the float. A new algorithm is proposed to calculate acceleration terms satisfying Newtonian kinematical equations. The computational requirement varies only linearly with the number of links because the algorithm is based on a sweep-out operation on a threefold diagonal matrix with a simple structure. A comparison is made with a well-known Featherstone algorithm that is based on articulated body inertias. Animation results with 22 links subjected to tidal flow and wave produce typical tackle behaviors consistent with expert experience. The animation is useful for design of tackles and discrimination drills of fish hits.

著者

城下 荘平 熊本 博光 永平 幸雄 西原 修

出版者

京都大学

雑誌

基盤研究(C)

巻号頁・発行日

2004

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明治になって欧米の先進諸国から近代機械技術が導入される以前の江戸時代に、我が国に存在したからくりは複雑な動きを、機械的な機構だけで行っている。それらの動きを実現している機械機構は、近代機械技術で用いられているものも含まれている。江戸時代の機械書、『機巧図彙』や『き訓蒙鑑草』にはそれらのからくりの機械機構が図解されているが、しかしながら、描かれている図が部分的過ぎて直感的に理解し難い。本研究では、からくりの中でも特に多様な機械機構を含んでいる"茶運人形"について、人形の各動作、すなわち、発進と停止の機構、足を前後に動かす機構、お辞儀をする機構、方向転換をする機構、逃し止め(エスケープメント)機構の理解し易い機構図を作成し、アニメーションを作成した。作成したアニメーションは京都大学総合博物館のウェブサイトに掲載した。そして、それらと近代機械機構を表しているルロー教育模型とを比較することで、江戸時代の機械技術を検証した。また、からくりやルロー模型に含まれている機械要素についても比較検討した。段返り人形についてもアニメーションを作成し、同様の検討を行った。これらの検討から、木や糸や鯨のヒゲで作られた江戸時代からくりの機械機構は高度ではあったが、金属を精密に切削加工する技術がなかったため、我が国においてからくりの機械技術が広く産業に応用されることはなかった、などのことが明らかとなった。

著者

西原 修 坂谷 祐輔 北野 弘明 平岡 敏洋 熊本 博光

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.74, no.738, pp.250-258, 2008-02-25 (Released:2011-08-16)

参考文献数

8

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The Meihan highway linking Kameyama in Mie Prefecture and Tenri in Nara Prefecture is one of most accident-prone areas in Japan. Representative accident factors that have been identified for the Meihan highway are chronic speeding and complex road alignments, including many sharp curves and steep slopes. One particular section is known as the “Omega curve” as the road shape is similar to the Greek character “Ω”. In this study, the probable effects of proposed plans to improve the road alignment of the Nakahata section are investigated by performing driving simulations to identify typical hazards, ranging from traffic conflicts to vehicle accidents. It was found that incidents that begin as a minor traffic conflicts can frequently escalate to become a fatal accidents. It was also found that improved road alignment generally reduces the required tire forces. For typical traffic conflict patterns reproduced using the driving simulator, it was found that road alignment resulted in considerable improvements in safety indexes which are effective indicators for the occurrence of rear-end collisions.

著者

山邉 茂之 熊本 博光 西原 修

出版者

公益社団法人精密工学会

雑誌

精密工学会誌論文集 (ISSN:13488724)

巻号頁・発行日

vol.72, no.7, pp.895-902, 2006-07-05

参考文献数

5

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This paper analyzes a fishing tackle consisting of bar float, line, sinker, hook line, subsinkers, and hook. Three arrangements of the subsinkers attached to the hook line are considered: 1) free design without sub-sinkers, 2) equal design with a pair of identical subsinkers, and 3) unequal design with a light sinker followed by a heavy one. Fluid-dynamic coefficients are identified to calculate, for instance, bar float drag and friction, and fishing tackle simulations are carried out using a multi-link model proposed by the authors. It turned out, among other things, that the free design can create a good float response to a weak fish bite.

著者

山邉 茂之 熊本 博光 西原 修

出版者

公益社団法人 精密工学会

雑誌

精密工学会学術講演会講演論文集 2005年度精密工学会秋季大会

巻号頁・発行日

pp.613-614, 2005-09-15 (Released:2006-04-18)

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棒浮き·道糸·錘·ハリス·ガン玉·ハリからなる仕掛け構成の種類·形状·配置·個数·重さの違いによる釣り仕掛けを考える.さらに,魚の引きの強さと当たり方向として上下左右とその中間の全八方向を考え,浮きに作用する力の大きさを明らかにし,波の速度やうねりの高さの違いによる水中における仕掛けの挙動変化をアニメーションで再現し,今まで視認できず難しかった釣り仕掛けの評価を行う.

著者

西原 修 平岡 敏洋 熊本 博光

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.72, no.714, pp.537-544, 2006-02-25 (Released:2011-03-04)

参考文献数

15

被引用文献数

11 11

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The present paper discusses the driving/breaking force distribution for direct yaw-moment control (DYC) of the independent steering vehicle. The objective function is the maximum value of the tire workloads. In the case of conventional four wheel steering vehicle, the algebraic expressions of the optimum driving/breaking force distribution have been derived by the authors. Based on the previous results, the optimization algorithms for the independent steering vehicle are newly developed. For the front independent steering vehicle, the binary search is employed, and this online algorithm is combined with the golden section search method for the independent four-wheel steering vehicle. The convergences are guaranteed by the convexities of these optimization problems. Numerical simulations with CarSim, a popular multi-degree-of-freedom vehicle model, are performed to prove effectiveness of the proposed control schemes.

著者

西原 修 松久 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 (ISSN:03875024)

巻号頁・発行日

vol.63, no.614, pp.3438-3445, 1997

被引用文献数

23

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Fixed points design methods for dynamic vibration absorbers are very well-known in the field of vibration control and commonly applied for practical absorber design. However, they must be understood to be approximation methods from the point of view of their design criterion that the resonance amplitude magnification factor is minimized. In this study, the exact algebraic expressions of optimum tuning and damping parameters for the minimization of the largest resonance amplitude magnification factor of linear dynamic vibration absorbers have been derived for undamped primary systems. The existence of two equal height resonance points is reduced to a multiple root condition of an algebraic equation. The determinant is handled as an equation with respect to the resonance amplitude. It has became very clear that the fixed points theory design by Brock is highly accurate. In particular, it exhibits very small error in the practical mass ratio range, e.g., below unity. Algebraic solutions also exist for the resonance frequencies and the anti-resonance frequency. A numerical extension of the method is introduced in order to investigate the optimization problem for damped primary systems.

著者

西原 修

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.849, pp.16-00549-16-00549, 2017 (Released:2017-05-25)

参考文献数

15

被引用文献数

9

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The optimal design method of double-mass dynamic vibration absorbers (DVAs) is discussed with respect to the minimization of the maximum amplitude magnification factor. The performance of a double-mass DVA is superior to a single-mass DVA with the same mass ratio, although the design methods are still the subject of studies. The design optimizations of double-mass DVAs that are arranged in parallel or series are formulated precisely using an optimality criteria approach in which the optimal parameters are obtained as the numerical solutions of simultaneous algebraic equations. The primal equations are derived using Vieta’s formula with the assumption that the optimal design is realized with three resonant points of equal height. The additional equations are derived as the determinants of Jacobian matrices that are defined using the primal equations. After rearrangement, these formulations realize the direct numerical solution of the design optimization via the solution of simultaneous algebraic equations. Examples are provided that prove the effects of double-mass DVAs. The formulations used in this study are variants of the algebraic approach developed by the author that realized the closed-form algebraic exact solutions to a popular design optimization of a single-mass DVA. The well-known design formulae that use the fixed points by J. P. Den Hartog and J. E. Brock correspond to an approximate solution to this problem.

著者

西原 修 松久 寛 佐藤 進

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. C編 (ISSN:03875024)

巻号頁・発行日

vol.60, no.580, pp.4098-4106, 1994-12-25

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The design optimization of passive vibration control mechanisms in the accelerance domain is discussed. In this study, the fixed points theory is developed which approximately minimizes the maximum accelerance in the frequency domain by equally adjusting the accelerance of two fixed points. This design method is applied to the dynamic vibration absorber (DVA) and the passive gyroscopic damper (PGD), and thus the maximum accelerances of these mechanisms are successfully reduced. The concept of the fixed points theory is reinvestigated. The accuracy and the degree of improvement compared with the fixed points design in the compliance domain are examined. The PGD realizes relatively higher damping effects, and then the accelerance reduction of the PGD by the new design method is considerably larger than that of the DVA with a moderate mass ratio.

著者

西原 修 松久 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 (ISSN:03875024)

巻号頁・発行日

vol.63, no.614, pp.3438-3445, 1997-10

参考文献数

6

被引用文献数

9

---

Fixed points design methods for dynamic vibration absorbers are very well-known in the field of vibration control and commonly applied for practical absorber design. However, they must be understood to be approximation methods from the point of view of their design criterion that the resonance amplitude magnification factor is minimized. In this study, the exact algebraic expressions of optimum tuning and damping parameters for the minimization of the largest resonance amplitude magnification factor of linear dynamic vibration absorbers have been derived for undamped primary systems. The existence of two equal height resonance points is reduced to a multiple root condition of an algebraic equation. The determinant is handled as an equation with respect to the resonance amplitude. It has became very clear that the fixed points theory design by Brock is highly accurate. In particular, it exhibits very small error in the practical mass ratio range, e.g., below unity. Algebraic solutions also exist for the resonance frequencies and the anti-resonance frequency. A numerical extension of the method is introduced in order to investigate the optimization problem for damped primary systems.

著者

松久 寛 西原 修 本田 善久 柴田 俊忍 佐藤 進

出版者

京都大学

雑誌

一般研究(C)

巻号頁・発行日

1990

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スキ-時の人体の上下運動に関してはひざをリンク機構、筋肉を収縮要素、それと直列につながる弾性要素、並列の減衰要素で模擬した。ひざは大きく曲げる程ばねが柔らかくなるリンク機構による幾何学的非線形性を持ち、筋肉はばねと減衰からなる受動的なダンパ-としての役割と収縮による能動的な運動を行う。動特性としてはひざを深く曲げる程緩衝効果は大きくなるが、筋肉にかかる荷重は大きくなる。能動的に立ち上がる場合は立ち上がりの前半に雪面への押し付け力が増加し、後半に減少する。この雪面押し付け力の増加減少をタイミングより利用することによって、雪面の凸凹による体の不安体を安定化することができる。またスキ-板をはりとして、足首で力とモ-メントが働くとして人体とスキ-板の連成振動の解析モデルを作成した。ここで、人体の動きとスキ-板の形状、剛性などとタ-ンの関係が明らかになった。テニスに関してはボ-ルを一つの質点と一つのばね、ラケットを弾性はり、ガット面を一つのばね、腕を回転とねじり方向各3自由度のばね・質点系でモデル化した。ここで、腕のモデル化においては、腕をインパルス加振したときの各部の回転角加速度を計測し、時系列デ-タの最小自乗法によって各係数を同定した。そして数値計算によって、ボ-ルの飛距離、腕にかかる衝撃力の関係を明らかにした。また、ラケットの特性、すなわち曲げ剛さや、ガットのはり具合の影響についても検討し、このモデルがほぼ妥当なものであることがわかった。また、ラケットの構造の変化、すなわち重心位置とボ-ルの飛距離や手にかかる衝撃力の関係についても検討した。これらの研究により、人体の力学モデルの作製法およびスポ-ツ用具の解析法が確立されたので、これらを組み合わせることにより、人体の運動時の動特性、特に関節にかかる応力等を求める手法が得られた。