Sensorization of continuum soft robots for reconstructing their spatial configuration

This work deals with the sensorization of continuum soft robots for reconstructing their spatial configuration. Since at the present time the proprioceptive perception is prevalently achieved using external 3D optical methods, an embedded system is needed for the improvement of the performances of this promising kind of robots. The idea is to use stretch sensors to reconstruct the spatial configuration of a robotic structure: differential measurements on strain values can be used to derive local curvatures performed by the arm. Strain values have been extracted using a conductive textile that presents very high elasticity and lightness. The main feature is that its electrical resistance depends on its mechanical strain and it has been characterized in order to derive this strain-resistance relation. The reconstruction method that allows to obtain spatial configuration from material deformations is then reported. A practical application on reconstructing the configuration of an octopus-inspired robot arm is finally shown and discussed.