Affiliations: [a] Department of Adaptive Machine Systems, Graduate School of Engineering, Osaka University, Osaka, Japan | [b] Department of Systems Innovation, Graduate School of Engineering Science, Osaka University, Osaka, Japan
Correspondence:
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Corresponding author: Masahiko Sakai, Department of Adaptive Machine Systems, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan. Tel./Fax: +81 06 6879 7533; E-mail:masahiko.sakai@ams.eng.osaka-u.ac.jp
Abstract: This paper presents a helical teethed linear actuator
(HTLA) for artificial muscles of human coexistence robots. The HTLA has
small number of simple-shaped permanent magnets and coils. The advantages of
this actuator are a high force constant and capability of accurate assembly.
The performances of the HTLA were investigated by using 3-D finite element
method (FEM). As a result, it was found that the maximum thrust force was
23.1 N, and the efficacy of the PID position control for the HTLA was
confirmed. In addition, by the force control using encoder signals, the
detent force was decreased to 0.56 N and the force constant was 34.9 N/A.
Moreover, the control of the stiffness for flexible motions was implemented
by using compliance control.
Keywords: Electromagnetic linear actuator, artificial muscle, helical teeth, force control, 3-D finite element method
