Preliminary Study on Shape Sensing for Continuum Robot Affected by External Load Using Piecewise Fitting Curves

This paper proposes a new method of shape sensing for continuum robot affected by external load using piecewise fitting curves. This scheme will integrate posture sensors into continuum robot, and then the shape is reconstructed by piecewise fitting Bézier curves. The simulation analysis is used to analyze the curvature and radius change of each section of the continuum robot, when the end of the bending continuum robot with constant curvature is subjected to external load. The layout scheme of sensors is determined according to the curvature and radius of each section. The shape of image recognition is compared with the shape of piecewise fitting cubic Bézier curves in simulation. The maximum tracking error is 1.4 mm and the minimum tracking error is 0.006 mm. The simulation results verify the accuracy and feasibility of this method.