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Ch26-I044963.fm Page 125 Tuesday, August 1, 2006 3:00 PM
Page 125
Tuesday, August
1, 2006
3:00 PM
Ch26-I044963.fm
125
125
ASSEMBLY SYSTEM BY USING PROTOTYPE
OF ACTIVE FLEXIBLE FIXTURE
2
1
T. Yamaguchi , M. Higuchi and K. Nagai 3
'Department of Mechanical Engineering, Kansai University
3-3-35 Yamate-cho, Suita, Osaka 564-8680 JAPAN
2
Department of Mechanical System Engineering, Kansai University
3-3-35 Yamate-cho, Suita, Osaka 564-8680 JAPAN
Department of Robotics, Ritsumeikan University,
1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 JAPAN

ABSTRACT

Our goal is the development of fixture with the function of handling of various works with
practicability in automated assembly system for job shop type production. This paper describes the
"active flexible fixture (AFLEF)" on plane level as a prototype of the goal. The AFLEF is an active and
practical fixture, and it can fix any work rigidly and position the work at a few millimeters to correct
the position error after holding. It is multi-fingered hand type, but it is not more dexterous than general
hands of this type but more practical than those. As results of the experiments in rigid fixing and short
positioning, the fixture rigidity to external force was within about 0.031 mm/N and 0.88 deg./N-m and
the maximum error in positioning of a fixed work at ±3.0 mm or ±3.0 deg. was within about 0.3 mm
and 0.3 deg..

KEYWORDS

Fixture, Job shop type production, Automated assembly, Peg-in-hole task, Multi-fingered hand

1. INTRODUCTION
The function of handling various works with practicability has been required for automated assembly
system in job shop type production. A usual automated assembly unit is composed of a manipulator
with a robot-hand and a fixture. In order to equip the manipulator with the above function, many
researchers, e.g. Rapela et al. (2002), tried assembly task by using a multi-fingered robot-hand. On the
other hand, in order to equip the fixture with the function, some researchers, e.g. Asada and By (1985),
Lee and Cutkosky (1991), Brost and Goldberg (1996) and Cai et al. (1997), applied the modular fixture
like T-slot type, dowel type, or pin-array type. However, since the positioning of the tool like dowel,
pin, etc. is passive, it is hard to rearrange the fixture layout immediately for the change of work, i.e.
this type of fixture is not suitable for practical assembly. Thus the active function is also needed for the
fixture suitable for practical assembly. Some active fixtures were developed by Grippo et al. (1988),
Hazen and Wright (1990), Chan and Lin (1996), and Kimura and Yashima (1996). However, any