Kinematic analysis of continuum robots based on vector form intrinsic finite element method

Abstract

Excellent compliance characteristics are demonstrated by rigid-flexible hybrid continuum robots that are made up of both elastic and flexible components. However, in conventional kinematic modeling techniques, their strong coupling nature results in high computational complexity and inadequate accuracy. In this work, kinematic models for cable-driven and pneumatically actuated continuum robots are developed using the Vector Form Intrinsic Finite Element (VFIFE) method. We developed a VFIFE-based forward kinematic model using finite spatial node simulation, which combines mass point discretization, the virtual reverse motion principle, and the central difference method. Accurate deformation prediction is made possible by this method, especially when examining large quasi-static deformations. The effectiveness of the suggested method is validated by simulation and experimental results, which show that the displacement error between the proposed model and the ADAMS/Simulink co-simulation model is less than 5% and that the VFIFE-based mechanical model exhibits over 90% agreement with the trajectory of the physical prototype experiments. This modeling framework offers theoretical support for real-time control and path planning in a variety of robotic systems made up of strut, cable, and beam elements while overcoming the drawbacks of conventional approaches in rigid-flexible hybrid systems.