Using physical modeling and RGB-D registration for contact force sensing on deformable objects

In this paper we propose a method to estimate the force applied to a manipulated deformable object by processing information provided by an external vision sensor, in this case a consumer RGB-D camera. By measuring the deformations undergone by the object through a registration technique, the idea is to retrieve the contact force which minimises the deviation between the measured and the simulated deformations, given a simple interaction model and by employing a fitting process. The system resorts to a realistic mesh-based Finite Element Method model to accurately model deformations, whose elastic parameters are estimated in advance using the vision system and a force sensor. Experimental results are presented for the case of a compressive point-wise contact force applied, at static equilibrium, on a deformable object