A modular approach for dynamic modeling of multisegment continuum robots

Abstract

The accurate dynamic model for continuum robots is necessary to expand their range of applications. In this paper, a modular approach is proposed for dynamic modeling of cable-driven multisegment continuum robots. The previous dynamic models are usually formulated as a set of ordinary differential equations. However, the derived dynamic model in this paper is formulated as a set of differential-algebraic equations, resulting in the coefficient matrices of adjacent modules being decoupled. Reformulation of the existing coefficient matrices is not required as the number of modules increases, which makes the presented approach suitable for modular modeling. The continuum deformations, including elongation or contraction, bending, and torsion, are taken into account. Hermite interpolation is adopted to describe the flexible shape of each backbone, avoiding the singularity and additional constraints of constant strains. Static and dynamic experiments were implemented on continuum robot prototypes. The normalized errors are less than 3.83% and 6.93% of the robot length in the static and dynamic experiments. The presented model is experimentally validated.