Prescribed performance sliding mode control for the PAMs elbow exoskeleton in the tracking trajectory task
ISSN: 0143-991x
Article publication date: 5 December 2023
Issue publication date: 26 January 2024
Abstract
Purpose
This study discusses the tracking trajectory issue of the exoskeleton under the bounded disturbance and designs an useful tracking trajectory control method to solve it. By using the proposed control method, the tracking error can be successfully convergence to the assigned boundary. Meanwhile, the chattering effect caused by the actuators is already reduced, and the tracking performance of the pneumatic artificial muscles (PAMs) elbow exoskeleton is improved effectively.
Design/methodology/approach
A prescribed performance sliding mode control method was developed in this study to fulfill the joint position tracking trajectory task on the elbow exoskeleton driven by two PAMs. In terms of the control structure, a dynamic model was built by conforming to the adaptive law to compensate for the time variety and uncertainty exhibited by the system. Subsequently, a super-twisting algorithm-based second-order sliding mode control method was subjected to the exoskeleton under the boundedness of external disturbance. Moreover, the prescribed performance control method exhibits a smooth prescribed function with an error transformation function to ensure the tracking error can be finally convergent to the pre-designed requirement.
Findings
From the theoretical perspective, the stability of the control method was verified through Lyapunov synthesis. On that basis, the tracking performance of the proposed control method was confirmed through the simulation and the manikin model experiment.
Originality/value
As revealed by the results of this study, the proposed control method sufficiently applies to the PAMs elbow exoskeleton for tracking trajectory, which means it has potential application in the actual robot-assisted passive rehabilitation tasks.
Keywords
Acknowledgements
Erratum: It has come to the attention of the publisher that the article Zhao, Z., Hao, L., Tao, G., Liu, H. and Shen, L. (2023), “Prescribed performance sliding mode control for the PAMs elbow exoskeleton in the tracking trajectory task”, Industrial Robot, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/IR-06-2023-0122 displays Lina Hao’s affiliation incorrectly. This error was introduced during the submission process. Department of Mechanical and Engineering, Northeastern University, Boston, Massachusetts, USA has now been corrected to Department of Mechanical and Engineering, Northeastern University, Shenyang, China. The publisher sincerely apologises for this error and for any confusion caused.
National Natural Science Foundation of China; No.62073063; National Natural Science Foundation of China; No.62303330; Excellent Young Scientists Fund; No.52005348, Department of Education of Liaoning Province; No. LJKMZ20220525.
Citation
Zhao, Z., Hao, L., Tao, G., Liu, H. and Shen, L. (2024), "Prescribed performance sliding mode control for the PAMs elbow exoskeleton in the tracking trajectory task", Industrial Robot, Vol. 51 No. 1, pp. 167-176. https://doi.org/10.1108/IR-06-2023-0122
Publisher
:Emerald Publishing Limited
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