Using damping injection and passivity in robotic manipulation

In this article experimental results obtained adopting a control strategy for robotic manipulation based on passivity concepts are presented and discussed. The control strategy, that can be used for both tips and full grasps, can be framed in the context of impedance control, and it is characterized by two fundamental features. The first one is the so-called 'virtual object' concept, by means of which the modalities of interaction between the fingers and the real objects can be properly defined. The second feature is the 'damping injection' principle, which allows a stable execution of the planned task. Major advantages of this strategy are the physical intuition on which it is based and its passive nature that ensures stability in all the situations, including in particular the transition from no contact to contact and vice versa.