Extended state observer based fractional sliding-mode control strategy for continuum robot arms
CHEN Peng-chong
HUO Ben-yan
LIU Yan-hong
LUO Ying
Abstract：Continuous robot arms have broad prospects in unstructured environments,but existing control algorithms have limited disturbance rejection performance due to strong nonlinear dynamics,model uncertainties,and external distur-bances.This paper proposes a fractional sliding mode control strategy based on an extended state observer for end-effector trajectory tracking of continuous robot arms.The controller is designed based on the dynamic model of the continuous robot arms and consists of three parts.The first part is nonlinear dynamic feedback linearization,the second part designs an extended state observer to estimate and compensate for external disturbances and model uncertainties,and finally,a fractional sliding mode controller is designed to achieve closed-loop control.Furthermore,stability proofs for the extended state observer and the closed-loop system are provided.By comparing the tracking performance of different control strate-gies for given step angles,sine angles,and circular trajectories,the proposed control strategy is validated to be superior to other typical controllers in terms of trajectory tracking and suppression of external disturbances/model uncertainties.This provides a practical and feasible solution for precise control of continuum robotic arms.
Keywords：continuum robot armsextended state observerfractional sliding-mode controlmodel uncertaintiesex-ternal disturbance
Publication Date：2025-06-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 1066-1074 )