Static Modeling of Composite Continuum Robot Considering Coupling Effect

Abstract Continuum robots, characterized by their flexible and hyper-redundant structure, exhibit exceptional adaptability for navigating complex anatomical regions, demonstrating significant potential in minimally invasive surgical applications. This paper proposes a static model for the composite continuum robot incorporating the coupling effect. The tension transmission characteristics are derived by analyzing the driving cables’ frictional losses at nodal points. An accurate static model is established by considering both the end-load conditions of flexible beams and the coupling interactions between the concentric tube and notched continuum. Based on the coupling effect analysis and Euler-Bernoulli beam theory, deformation-driving relationships under various motion conditions are formulated for the composite continuum robot. Simulation and experimental verification demonstrate that the proposed static model achieves an average positioning error of 0.486 mm, exhibiting 1.846 times improvement in spatial accuracy compared with conventional constant curvature models. This static model provides theoretical foundations for precise control and clinical applications of composite continuum robots.