A Tendon-Driven Continuum Manipulator With Robust Shape Estimation by Multiple IMUs

In this letter, a tendon-driven continuum robotic manipulator with three individual continuum sections is developed and manufactured. The main contribution is that we propose a robust and accurate shape estimation method based on the fusion of multi-IMUs for the manipulator, under the PCC (Piecewise Constant Curvature) assumption. To intuitively present the robot's configuration space, we develop a visualization environment to showcase the real-time continuum shape. To validate the proposed system with the estimation method, we evaluate fundamental attributes such as the bending range, tip velocity, effective workspace, and durability. Furthermore, we conduct motion experiments of shape deformation, dynamic tracking, and disturbance resisting. The results show that our proposed estimation method is evaluated to achieve less than 20 mm RMSE on tip motion, during consecutive 3D motions. Meanwhile, we compare the proposed system with previous continuum robotic systems in mechanism properties. Our proposed robotic system has a more compact and efficient structure.