Discontinuous control of an underwater manipulator by a simplex of constant control vectors

The aim of this paper is that of summarizing the experience of design and realization of a home-made robotic finger based on nonconventional ideas. The device that we present in this paper is the exploitation of the concepts expressed in the context of an EC funded project called AMADEUS, in which the elephant-trunk principle is used for the implementation of an underwater gripper that we actuated by mean of high-bandwidth electrohydraulic devices working with oil at low pressure. The whole system is then controlled with a sliding mode based technique. The special manipulator based on the use of such fingers as described in this paper is devoted to delicate deep underwater sampling operations.