著者
小粥 雅貴 若松 栄史 森永 英二 荒井 栄司 島田 茂樹 眞鍋 賢
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.80, no.814, pp.TRANS0141-TRANS0141, 2014 (Released:2014-06-25)

In this paper, a prediction method of the maximum principal strain of a core/shielding wire contained in a coaxial cable, which is related to the life-cycle of the wire, is proposed. If the central axis of a wire is assumed to be twisted around a virtual cylindrical surface when a coaxial cable is straight and a virtual toroidal surface when the cable is bent, the shape of the wire can be described by the first and the second fundamental form of their surfaces in the differential geometry. The potential energy of the wire, which is bent, twisted, expanded, and/or contracted, is also formulated based on the differential geometry. Friction of the wire against the virtual surface is modeled as a virtual spring in the circumferential direction of the surface and its elastic energy is included in the total potential energy of the wire. Then, the stable shape of the wire can be computed by minimizing its total potential energy under geometric constraints. After that, the maximum principal strain is estimated from the shape of the wire. As a result of simulation, it was founded that a core wire is broken by bending fatigue before the shielding wire is if they have the same radius and rigidity.
著者
森安 竜大 若松 栄史 森永 英二 荒井 栄司 島田 茂樹 眞鍋 賢
出版者
一般社団法人 日本ロボット学会
雑誌
日本ロボット学会誌 (ISSN:02891824)
巻号頁・発行日
vol.30, no.8, pp.813-821, 2012 (Released:2012-11-15)

A modeling method to represent bending/torsional deformation of an electric wire is proposed based on the differential geometry. A twisted wire called a robot cable is used in a prismatic/rotational joint of an industrial robot to transmit signals or electric power. It is composed of a twisted bunch of several strands of many copper wires. The copper wire may be cracked by repeated bending/torsional deformation associated with the movement of a joint and such crack leads to wiring disconnection. To predict the life-cycle of the wires and to prevent such wiring disconnection, it is required to estimate deformation of not only the strands but also the copper wires when the wire is bent/twisted. In this paper, the deformed shape of a wire, which corresponds to a twisted bunch of n strands, is described by 3+2n independent variables and can be derived by minimizing the potential energy of each strand under various constraints. As the relationship between copper wires and their strand is similar with that between strands and their twisted bunch, the deformed shape of each copper wire can be also derived with the same method.
著者
熊本 睦 島田 茂夫 飯田 敏幸
雑誌
全国大会講演論文集
巻号頁・発行日
vol.45, pp.97-98, 1992-09-28

人間のように融通のきく柔軟な理解や判断を計算機に持たせることを目的として,量的な判断常識を備えた人工知能の研究を進めている。量的判断には,与えられたデータの中での大小を判断する相対的な量的判断と,万人の共通する常識から大小を判断する絶対的な量的判断の2種類がある。相対的な量的判断については,量的判断知識を表現する概念知識と定量化知識,および,量的判断能力を実現する推論機構と定量化機構から構成される人工知能で実現した。絶対的な量的判断のためには,さらに,量的判断の基準となる常識的な数値(常識値)や,常識値間の関係(常識関係)が必要となる。本稿では,常識値や常識関係の表現モデルとそれらを用いた量的判断手法について述べる。