An Effective Method on Applying Feedback Error Learning Scheme to Functional Electrical Stimulation Controller

Takashi WATANABE  Kenji KUROSAWA  Makoto YOSHIZAWA 

Publication
IEICE TRANSACTIONS on Information and Systems  Vol.E92-D  No.2  pp.342-345
Publication Date: 2009/02/01
Online ISSN: 1745-1361
Print ISSN: 0916-8532
Type of Manuscript: LETTER
Category: Rehabilitation Engineering and Assistive Technology
Keyword: 
functional electrical stimulation,  FES,  feedback error learning, 

Full Text: PDF(478.1KB)

Summary: 
A Feedback Error Learning (FEL) scheme was found to be applicable to joint angle control by Functional Electrical Stimulation (FES) in our previous study. However, the FEL-FES controller had a problem in learning of the inverse dynamics model (IDM) in some cases. In this paper, methods of applying the FEL to FES control were examined in controlling 1-DOF movement of the wrist joint stimulating 2 muscles through computer simulation under several control conditions with several subject models. The problems in applying FEL to FES controller were suggested to be in restricting stimulation intensity to positive values between the minimum and the maximum intensities and in the case of very small output values of the IDM. Learning of the IDM was greatly improved by considering the IDM output range with setting the minimum ANN output value in calculating ANN connection weight change.