Variable impedance control of finger exoskeleton for hand rehabilitation following stroke
ISSN: 0143-991x
Article publication date: 25 October 2019
Issue publication date: 16 January 2020
Abstract
Purpose
The purpose of this paper is to propose a variable impedance control method of finger exoskeleton for hand rehabilitation using the contact forces between the finger and the exoskeleton, making the output trajectory of finger exoskeleton comply with the natural flexion-extension (NFE) trajectory accurately and adaptively.
Design/methodology/approach
This paper presents a variable impedance control method based on fuzzy neural network (FNN). The impedance control system sets the contact forces and joint angles collected by sensors as input. Then it uses the offline-trained FNN system to acquire the impedance parameters in real time, thus realizing tracking the NFE trajectory. K-means clustering method is applied to construct FNN, which can obtain the number of fuzzy rules automatically.
Findings
The results of simulations and experiments both show that the finger exoskeleton has an accurate output trajectory and an adaptive performance on three subjects with different physiological parameters. The variable impedance control system can drive the finger exoskeleton to comply with the NFE trajectory accurately and adaptively using the continuously changing contact forces.
Originality/value
The finger is regarded as a part of the control system to get the contact forces between finger and exoskeleton, and the impedance parameters can be updated in real time to make the output trajectory comply with the NFE trajectory accurately and adaptively during the rehabilitation.
Keywords
Acknowledgements
This work is supported by the National Natural Science Foundation of China (Grant No. 61203347, 61673134), the Natural Science Foundation of Heilongjiang Province of China (Grant No. LC2017022) and the Postdoctoral Scientific Research Developmental Fund of Heilongjiang Province of China (Grant No. LBH-Q17071).
Citation
Zhang, F., Lin, L., Yang, L. and Fu, Y. (2020), "Variable impedance control of finger exoskeleton for hand rehabilitation following stroke", Industrial Robot, Vol. 47 No. 1, pp. 23-32. https://doi.org/10.1108/IR-02-2019-0034
Publisher
:Emerald Publishing Limited
Copyright © 2019, Emerald Publishing Limited