Robotic Interaction Through Compliant Interfaces: Modelling and Identification

In this work, a new model, able to emulate the interaction of a robot with the environment when viscoelastic phenomena occur, is presented. The starting point of this research activity has been the study of soft pads for dexterous manipulation but the results obtained are applicable to all situations which foresee the interaction of a robotic manipulator through/with a viscoelastic medium (e.g. robotic surgery). Based on the so called quasi-linear model, adopted to describe the behaviour of human hand pads and, more generally, of biological tissues, this model allows to overcome the problems tied to classical (linear) models, often used in the robotic field. A procedure aiming to obtain the parameters of this nonlinear model is developed on the basis of classical identification methods and of physical insights. Finally, through experimental tests on some viscoelastic materials (a polyurethane gel and a silicon rubber) the model is validated.