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Numéro
J. Phys. IV France
Volume 11, Numéro PR8, Novembre 2001
Fifth European Symposium on Martensitic Transformations and Shape Memory Alloys
Page(s) Pr8-559 - Pr8-564
DOI https://doi.org/10.1051/jp4:2001893
Fifth European Symposium on Martensitic Transformations and Shape Memory Alloys

J. Phys. IV France 11 (2001) Pr8-559-Pr8-564

DOI: 10.1051/jp4:2001893

Position control of a SMA microgripper

E. Just1, M. Kohl1 and S. Miyazaki2

1  Forschungszentrum Karlsruhe GmbH, IMT, Postfach 3640, 76021 Karlsruhe, Germany
2  Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan


Abstract
A SMA microgripper system with an integrated optical position sensor is presented. The microgripper consists of two actuation units and an optical slit fabricated from one piece of SMA material with overall dimensions of 2 x 5.8 x 0.23 mm3. The gripper is sandwiched by two substrates with an aligned photodiode and a photosensor, respectively. This transmission setup allows position sensing with a spatial resolution of 1 µm per 2.5% optical signal change. By feedback of the position signal to a PI controller a position error of 0.3% is achieved. The typical time constant for reaching stationary positions is about 140 ms.



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