1993 Fiscal Year Final Research Report Summary
Study on Automatic Centering Operations of Varieties of Workpieces Based on Non-linear Dynamic Analyzes of Contact Surfaces
| Project/Area Number |
03650104
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械工作
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
YOSHIMURA Masataka Kyoto University, Faculty of Engineering, Lecture, 工学部, 講師 (60026325)
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| Co-Investigator(Kenkyū-buntansha) |
YURA Kenji Kyoto University, Faculty of Engineering, Research Associate, 工学部, 助手 (50158341)
HITOMI Katsundo Kyoto University, Faculty of Engineering, Professor, 工学部, 教授 (40016308)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Centering operation / Dynamic analysis / Frictional force / Nonlinear analysis / Contact surface / Impulse force / Simulation / Workpiece |
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| Research Abstract |
The centering operation of workpieces is one of the most time-consuming jobs for which automation has not been established in Computer-Aided Manufacturing (CAM). As fundamental research for automating the centering operations, analytical models and methodologies needed for automating centering operations were proposed. First, the movement behaviors of a workpiece when applying an impulse force with a hammer were observed using experimental equipment and the relationships between the applied force and the displacement of the workpiece were measured. Then, frictional forces between a workpiece and a table were formulated as a nonlinear function of the velocity of the workpiece. Next, to obtain a displacement behavior of the workpiece on a table numerically, the movement of the workpiece was simulated by the finite element method (FEM) in which a nonlinear frictional force model was applied at the contact surface between the workpiece and the table. Finally, a method was constructed for determining the optimal impulse force for displacing a workpiece to a required postion on a table so that the positional error of the workpiece was minimum and numerical results were given to demonstrate the method. The results obtained by this study are itemized as follows :
(1) A frictional force model with four parameters of static frictional coefficient, dynamic frictional coefficient and two parametric values expressing the rising speed of the frictional force function was constructed.
(2) Computer simulation of workpiece displacement behaviors was conducted using the frictional force model and the finite element method. The simulated results have a good agreement with the measured ones.
(3) A method for determining the optimal impulse force for displacing a workpiece to a required position on a table was constructed and the method was demonstrated using numerical results.
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