Design and control of multi-step SMA actuator

Issue title: E-MRS Fall Meeting 2005

Article type: Research Article

Authors: Lee, Yun-Jung^{a; *} | Son, Hyung-min^a | Gu, Jun-bum^a | Nam, Tae-hyun^b

Affiliations: [a] School of Electrical Engineering and Computer Science, Kyungpook National University, 1370 Sankyukdong, Daegu 702-701, Korea | [b] Division of Materials Engineering and ERI, Gyeongsang National University, 900 Gazwadong, Jinju, Gyeongnam 660-701, Korea

Correspondence: [*] Corresponding author. Tel.: +82 53 950 6562; Fax: +82 53 950 5505; E-mail: yjlee@ee.knu.ac.kr

Abstract: To balance the control complexity and number of controlled positions, a novel multi-step SMA actuator is proposed that has multiple controlled positions and can be actuated by sensor-less and open-loop control. The proposed multi-step SMA actuator is constructed so that several electrical taps are connected to one SMA wire and the sections between the taps are all the same length. The controlled positions then vary stepwise according to the number of actuated sections. To control the multi-step SMA actuator, a PWM(pulse width modulated) voltage with an appropriate duty ratio is applied to designated sections while considering the resistance value of the sections, as well as the recommended current for the given SMA wire. To verify the effectiveness of the proposed multi-step SMA actuator, experiments were performed using a single nitinol wire actuator with a bias spring mechanism and electronic control system.

DOI: 10.3233/JAE-2006-725

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 23, no. 1-2, pp. 119-124, 2006