Deformable haptic model generation through manual exploration

Interaction with virtual deformable models is common in several haptic contexts, such as in medical training simulators. This paper presents a methodological procedure for the creation of such virtual models from their real-life counterparts. Both the surface geometry and the elastic parametrization of an object are reconstructed from position/force readings during an operator-assisted exploration of the object. A 3D mesh model is then generated from the surface contact points. The internal elastic modulus is found using the 3D finite element method. This modeling method is compared with two common 1D elastic models, namely Kelvin-Voigt and Hunt-Crossley. Results using three deformable homogeneous silicone samples show successful geometry reconstruction. 1D model parameterizations exhibit high variation dependent on geometry and contact location. In contrast, elastic modulus reconstruction yields a global model parameterization independent of geometry. Elastic moduli estimated in experiments correlated with their known values, and were shown to be reproducible among samples with different geometries.