Abstract-In this letter, we propose a new framework of external force sensing for soft robots based on the fusion of vision-based measurements and finite element model (FEM) techniques. A precise mechanical model of the robot is built using real-time FEM to describe the relationship between the external forces acting on the robot and the displacement of the predefined feature points. The position of these feature points on the real robot is measured using a vision system and is compared with the equivalent feature points in the finite element model. Using the compared displacement, the intensities of the external forces are computed by solving an inverse problem. Based on the developed FEM equations, we show that not only the intensities but also the locations of the external forces can be estimated. A strategy is proposed to find the correct locations of external forces among several possible ones. The method is verified and validated using both simulation and experiments on a soft sheet and a parallel soft robot (both of them have nontrivial shapes). The good results obtained from the experimental study demonstrate the capability of our approach. Index Terms-Soft robot, external forces estimation, feature points allocation, finite element method.
A general strategy for soft robots with complex configurations is proposed in REF where both the location and the intensity can be estimated based on the deflection of markers.
Vision-Based Sensing of External Forces Acting on Soft Robots Using Finite Element Method
IEEE Robotics and Automation Letters
IEEE Robotics and Automation Letters
Engineering