Page 144 - Mechatronics for Safety, Security and Dependability in a New Era

Ch26-I044963.fm Page 128 Tuesday, August 1, 2006 3:00 PM
Ch26-I044963.fm
128
128 Page 128 Tuesday, August 1, 2006 3:00 PM
TABLE 2
REAL POSITIONING IN EACH DIRECTION FOR SHORT POSITIONING BY USING THE PROTOTYPE OF AFLEF
X-direction mm Y-direction mm 9-direction deg.
Reference displacement
+3.0 -3.0 +3.0 -3.0 +3.0 -3.0
X-axis mm 0.24 -0.29 -0.09 0.00 0.08 -0.11
Real displacement at each axis Y axis mm 0.03 -0.01 0.19 -0.28 -0.11 0.05
8-axis deg. 0.2 -0.1 -0.1 0.1 0.3 -0.2

displacements were measured with the same CCD camera. As can be seen from Table 2, the positioning
error in each positioning is within ±0.3 mm (translation) and ±0.3 deg. (rotation). These real errors
agree with theoretical those founded from the positioning performance of each driving joint.

4. CONCLUSIONS
We have developed the 2-dimensional active flexible fixture (AFLEF) with the generally conflicting
functions of rigid fixing and short positioning. As a result of experiment, 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.. Thus, in the prototype
of AFLEF, the function of rigid fixing was compatible with that of short positioning. We have tried to
realize the 3-dimensional AFELF by the improvement of the contact-tip and the additional of a vertical
translational joint.

REFERENCES

Asada H. and By A. B. (1985). Kinematic Analysis of Workpart Fixturing for Flexible Assembly with
Automatically Reconfigurable Fixtures. IEEE Journal of Robotics and Automation RA-1:2, 86-94.
Brost R. C. and Goldberg K. Y. (1996). A Complete Algorithm for Designing Planar Fixtures Using
Modular Components. IEEE Transactions on Robotic and Automation 12:1, 31-46.
Cai W, Hu S. J. and Yuan J. X. (1997). A Variational Method of Robust Fixture Configuration Design
for 3-D Workpieces. Transactions of the ASME, Journal of Manufacturing Science and Engineering
119:4A, 593-602.
Chan K. C. and Lin C. S. (1996). Development of a Computer Numerical Control (CNC) Modular
Fixture - Machine Design of a Standard Multifinger Module. International Journal of Advanced
Manufacturing Technology 11:1, 18-26.
Grippo P. M., Thompson B. S. and Gandhi M. V. (1988). A Review of Flexible Fixture Systems for
Computer-integrated Manufacturing. International Journal of Computer-Integrated Manufacturing
1:2, 124-135.
Hazen F. B. and Wright P. K. (1990). Workholding Automation: Innovations in Analysis, Design and
Planning. Manufacturing Review 3:4, 224-237.
Kimura H. and Yashima M. (1996). Dynamics and control of intelligent jig with function of
manipulation. JSME International Journal Series C, Dynamics Control Robotics Design and
Manufacturing 39:3, 549-559.
Lee S. H. and Cutkosky M. R. (1991). Fixture Planning with Friction. Transactions of the ASME,
Journal of Engineering for Industry 113:3, 320-327.
Osumi H. and Arai T. (1994). A Method for Introducing Industrial Robots to Cooperative Tasks.
Journal of the Robotics Society of Japan 12:8, 1192-1197 (In Japanese).
Rapela D. R., Rembold U. and Kuchen B. (2002). Planning of Regrasping Operations for a Dexterous
Hand in Assembly Tasks. Journal Intelligent & Robotic Systems 33:3, 231 -266.