著者

篠原 主勲 榊原 大智

出版者

一般社団法人 品質工学会

雑誌

品質工学 (ISSN:2189633X)

巻号頁・発行日

vol.28, no.5, pp.32-40, 2020-10-01 (Released:2023-01-17)

参考文献数

5

被引用文献数

1

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In search of a ball throwing technique for bowling perfect game, the quality engineering approach was used to determine a robust technique that would not depend on the lane condition. Noise factors such as the dynamic friction coefficient of the lane which the bowler cannot control, and control factors which the bowler can control, were selected; appropriate throwing levels were found by quality engineering; and these appropriate levels were adopted as a set of basic levels. The basic levels can then be tuned on the basis of pocket and pin action heuristics to derive the optimal throwing trajectory. Strikes can be obtained by maintaining the optimal trajectory while tuning only the speed of the ball to deal with factors that the bowler cannot control, such as the dynamic friction of the lane.

著者

篠原 主勲 奥田 洋司

出版者

一般社団法人 日本機械学会

雑誌

最適化シンポジウム講演論文集 2008.8 (ISSN:24243019)

巻号頁・発行日

pp.25-30, 2008-11-26 (Released:2017-06-19)

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To obtain the optimal shape of a 3D object minimizing the fluid traction, an adjoint variable method based on the variational principle is formulated and applied to the finite element method. The optimality condition of the present method consists of the state equations, the adjoint equations, and the sensitivity equations. In high Reynold's number cases, shape optimization methods are demanded that the initial shape be sufficiently close to the optimal shape and that Korman vortices not be present in the computational domain. Therefore, these methods were geneally applied to the steady state of the flows. In the present paper, the 3D adjoint variable method used to decrease the traction force of an object in unsteady flow is formulated by using FEM. The particularity of this method resides in the fact that both the start of the test time and the end of the test time in the optimization are determined by the stationary condition of the Lagrange function. The state variable is calculated from the start of the test time to the end of the test time in forward time and this data is saved, while the adjoint variable is calculated in backward time by using the saved data. The algorithm of the method is implemented using HEC-MW. By using the prepared algorithm, robust convergence of the cost function can be attained. This robustness makes possible the shape optimization even under unsteady flow containing Karman vortices.