Controller for a high strain shape memory alloy actuator: quenching of limit cycles

Author

Grant, Danny ; Hayward, Vincent

Author_Institution

Dept. of Electr. Eng., McGill Univ., Montreal, Que., Canada

Volume

1

fYear

1997

fDate

20-25 Apr 1997

Firstpage

254

Abstract

Further development of a three level switching controller (Grant and Hayward, 1995) is presented. The controller was originally designed to drive a novel shape memory alloy (SMA) actuator consisting of a number of thin NiTi fibers woven in a counter rotating helical pattern around supporting disks. While the original controller performed satisfactorily, it was hampered by the presence of limit cycles at higher gains. By allowing the upper switching level to be proportional to the velocity if is possible to achieve a damped response, analogous to PD control for linear systems, effectively quenching the limit cycle. With this damping, it is possible to decrease the rise time by almost half and maintain the same steady state accuracy

Keywords

actuators; control system synthesis; damping; limit cycles; robust control; shape memory effects; variable structure systems; NiTi; damped response; damping; high strain shape memory alloy actuator; limit cycles; rise time; steady state accuracy; thin NiTi fibers; three level switching controller; upper switching level; Actuators; Capacitive sensors; Counting circuits; Drives; Limit-cycles; PD control; Performance gain; Shape control; Shape memory alloys; Strain control;

fLanguage

English

Publisher

ieee

Conference_Titel

Robotics and Automation, 1997. Proceedings., 1997 IEEE International Conference on

Conference_Location

Albuquerque, NM

Print_ISBN

0-7803-3612-7

Type

conf

DOI

10.1109/ROBOT.1997.620047

Filename

620047