精密工学会誌
Online ISSN : 1882-675X
Print ISSN : 0912-0289
ISSN-L : 0912-0289
88 巻, 10 号
選択された号の論文の17件中1~17を表示しています
特集:専門委員会・分科会研究レビュー
展望
私の歩んできた道
グラビアとインタビュー 精密工学の最前線
はじめての精密工学
研究所・研究室紹介
 
論文
  • 花井 宏旭, 三浦 諄之, 三島 明, 廣垣 俊樹, 青山 栄一
    2022 年 88 巻 10 号 p. 773-780
    発行日: 2022/10/05
    公開日: 2022/10/06
    ジャーナル フリー

    The objective of this study was to automate the dual-arm coordination of an industrial humanoid robot when using a musical saw as a percussion instrument to produce a target sound. Especially, this report focuses on a humanoid robot with a characteristic of the real-time control to replace the traditional teaching and playback motion control. Meanwhile, it is assumed that the humanoid robot works in the environment that is near to a human being. To adapt in such situation, we aim to achieve the complex work using an advanced tool with its robot, as we perform a skillful motion. In the present report, we examine the performance of a musical saw using a bow because it is a kind of complex work using an unknown and advanced tool. Moreover, both the control method of the arm of the robot and the performance of the bow are discussed to construct a sound feedback control approach. As a result, it is demonstrated that the proposed approach has potential for both industrial and recreational applications of humanoid robots in human occupied environments.

  • 村上 浩規, 畝田 道雄, 大井 恭, 横山 詳悟, 石川 憲一
    2022 年 88 巻 10 号 p. 781-788
    発行日: 2022/10/05
    公開日: 2022/10/06
    ジャーナル フリー

    It is well known that the shape (appearance) is one of the components showing the beauty of Japanese swords. Furthermore, the famous and historical Japanese swords are considered to have more elegances and dignity. Currently, the superiority and inferiority evaluations of modern Japanese swords are performed by experts who have deep knowledge, and these swords are ranked the values according to each expert's sensibility. However, it is difficult to understand these evaluation results for ordinary people who are not familiar with them. Therefore, this study aims to analyze the shape of the modern Japanese swords as well as to propose the design approach using neural networks. In addition, we measured the cross-sectional features of the modern Japanese sword by laser displacement sensor and elucidated the relationships between the length and the cross-sectional features with the curve fitting method. As a result, we can succeed in the optimum design of the modern Japanese sword based on our analysis. Finally, our designed modern Japanese sword was exhibited in the contest held in 2021, and its good effectiveness was verified by the experts.

  • 中川 正夫, 山本 裕之, 高橋 利道, 實吉 敬二
    2022 年 88 巻 10 号 p. 789-794
    発行日: 2022/10/05
    公開日: 2022/10/06
    ジャーナル フリー

    A validation system is developed in this study to validate the distance measurement performance of the stereo cameras in a restricted space. In this system, a display shows the images to the stereo camera, and conversion lenses adjust the working distance of the stereo camera. Left-right images generated by simulation are shown independently to the left-right cameras of the stereo camera to generate the parallax for the distance measurement. Furthermore, distortion occurs on the captured images due to the conversion lenses, when the stereo camera captures the image through them. An inverse distortion grid is calculated with a known dot picture, and it is added to the left-right images on the display to cancel the distortion by conversion lenses.

  • 山田 慎之介, 山口 貢, 古本 達明
    2022 年 88 巻 10 号 p. 795-800
    発行日: 2022/10/05
    公開日: 2022/10/06
    ジャーナル フリー

    The Additive Manufacturing (AM) die & mold, which has conformal cooling channel manufactured by PBF-LB/M process, will be deliver high performance in terms of improvement of thermal fatigue. In tool steel SKD61 for AM die & mold often occurs surface crack due to abnormal surface roughness that occur during the build process. In the process, powder bed (PB) quality influenced by powder properties is one of the key factors to determine the quality of built parts. However, in terms of quantitative relationship between PB quality and powder flow-ability, there are few reports. In this study, SKD61 powders with different flow-ability (powder shear properties) due to different particle shapes were prepared and the effect of shear properties on PB roughness was investigated using the evaluation machine specialized in powder recoat process. As a result, PB roughness has a good correlation with angle of internal friction, PB roughness and PB roughness stability corresponding to powder recoat speed change showed increase with increasing angle of internal friction. It was found that it is important for PB quality to control angle of internal friction influenced by particle shapes of mean particle diameter d50 or over.

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