著者

後藤 真宏 西谷 弘信 宮川 浩臣 柳川 恭広

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.54, no.499, pp.497-502, 1988-03-25 (Released:2008-02-21)

参考文献数

13

被引用文献数

2 2

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Using a series of base oils of different viscosity grades, rotating bending fatigue tests of 0.34 % C steel plain specimens were carried out to examine the effect of oil environments on the fatigue behavior. Although the effect of oil is hardly observed in one grain size crack initiation process, its effect appears in the crack propagation process. As the main effects of oil, two actions are considered ; that is, the isolation of the atmosphere and the oil wedging action. The propagation of a crack smaller than 0.1mm is controlled mainly by the former effect. For a crack larger than 0.1mm, its behavior is controlled mainly by the latter effect. On the other hand, the effect of oil on the fatigue limit is very small.

著者

宮川 浩臣 西谷 弘信

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. A編 (ISSN:03875008)

巻号頁・発行日

vol.51, no.462, pp.445-449, 1985-02-25

被引用文献数

3 1

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This paper is concerned with the beneficial effects due to additional holes or indentations. Two indentations facing each other with the tip of a crack is especially effective in retardation of crack propagation. The effects of the indentations can be estimated approximately from the existence of residual stresses produced by the indentations.

著者

大西 謙吾 宮川 浩臣 田島 孝光 斎藤 之男

出版者

バイオメカニズム学会

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

vol.16, pp.155-165, 2002 (Released:2004-09-01)

参考文献数

22

被引用文献数

1

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Demand for fine human function modeling methodology is rising with the popularization of assistive devices. Systems engineering based research that delves into the functional cooperative relationship of the digits, hand, and arm is needed for design of substitutive mechanisms and for their control of the human body. The optimal tool for such research is the design process of a sensor-based robotic hand-arm system. This paper discusses the research issues and our proposed strategy.Our research goal is to develop a sensory-controlled mechanical system for performing versatile human-like prehension. As a design concept, we propose an effective model extracted from functional analysis of the upper limb. The key assumption in categorizing hand behavior is the arm’s driving function. Without proper integration of the two, the hand function can be neither analyzed nor assembled. Our approach uses this assumption as its base; we propose a method for classifying a non-redundant relation to control the dynamic and static use of the artificial upper limb.We began remodeling the degrees of freedom (DOF) of the human hand by identifying the transverse and longitudinal adjustable arch structure in the hand. Our new model is composed of 21 active DOF, which include movement in the palm. We classified movements and postures of the hand and arm with this DOF model located at the end of a seven-DOF arm. We then classified the hand modes as prehensile forms and sustentacular forms.Based on this model and our previous research experience in developing prosthetic upper limbs and anthropomorphic robotic hands, we devised a robotic hand-arm with a total of 24 degrees of freedom. Additionally, a new multitactile sensor has been developed for use on the robotic hands in our laboratory at TDU.For generating control strategy, the behavior of the hand is classified into two divisions. The first is cooperation of the digits and palm, and the second is cooperation of the hand and arm modules. The digit cooperation task is fourfold: formation, transformation, deformation, and hold. A motion planner drives the digit movements from the relation of the hand forms to the task that is proposed.A tactile sensor-based control strategy is presented. The digits are controlled according to the hand modes and the sensory feedback loop, with slippage detection rules. Two strategies are proposed for extending the control for fine manipulation: cooperative slippage sensing of adjacent digits, and slippage prediction applying hand orientation information measured by an inclinometer.The overall objective of our approach is the design of a dexterous control system for a multi-DOF robotic upper limb. This includes discussion of a modeling method for the human upper limb.