Research on fuzzy impedance control of upper-limb rehabilitation robot based on membership functions online optimization learning strategy
ISSN: 0143-991X
Article publication date: 16 October 2023
Issue publication date: 26 January 2024
Abstract
Purpose
To improve the position tracking efficiency of the upper-limb rehabilitation robot for stroke hemiplegia patients, the optimization Learning rate of the membership function based on the fuzzy impedance controller of the rehabilitation robot is propose.
Design/methodology/approach
First, the impaired limb’s damping and stiffness parameters for evaluating its physical recovery condition are online estimated by using weighted least squares method based on recursive algorithm. Second, the fuzzy impedance control with the rule has been designed with the optimal impedance parameters. Finally, the membership function learning rate online optimization strategy based on Takagi-Sugeno (TS) fuzzy impedance model was proposed to improve the position tracking speed of fuzzy impedance control.
Findings
This method provides a solution for improving the membership function learning rate of the fuzzy impedance controller of the upper limb rehabilitation robot. Compared with traditional TS fuzzy impedance controller in position control, the improved TS fuzzy impedance controller has reduced the overshoot stability time by 0.025 s, and the position error caused by simulating the thrust interference of the impaired limb has been reduced by 8.4%. This fact is verified by simulation and test.
Originality/value
The TS fuzzy impedance controller based on membership function online optimization learning strategy can effectively optimize control parameters and improve the position tracking speed of upper limb rehabilitation robots. This controller improves the auxiliary rehabilitation efficiency of the upper limb rehabilitation robot and ensures the stability of auxiliary rehabilitation training.
Keywords
Acknowledgements
Funding statement: This work is supported by Scientific Research Project of Zhejiang Province Education Department of China(No.Y202145975 and Y202249228) and High level talents special research on the public welfare technology application of Huzhou Vocational & Technical College(No.2022GY16 and 2022GY20).
Conflicts of interest: The authors declare that there are no conflicts of interest regarding the publication of this paper.
Citation
Wang, P. and Dong, R. (2024), "Research on fuzzy impedance control of upper-limb rehabilitation robot based on membership functions online optimization learning strategy", Industrial Robot, Vol. 51 No. 1, pp. 58-72. https://doi.org/10.1108/IR-07-2023-0146
Publisher
:Emerald Publishing Limited
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