Experimental results on task priority and dynamic programming based approach to underwater floating manipulation

This work presents the experimental results of the control methodology used to tackle the floating underwater manipulation aspects of the EU-FP7 TRIDENT project, whose main goal is to develop a multipurpose I-AUV (Intervention Autonomous Underwater Vehicle). In particular, the work focuses on the coordination aspects of the whole system, aimed at exploiting the high number of degrees of freedom that the arm and the vehicle have, for achieving a dexterous object grasping. To do so, the control strategy must also take into account all of a series of other objectives, both concerning safety and operational enabling aspects. Examples of such objectives are the arm joint limits and keeping the object grossly centered inside the camera frame. The developed methodology is based on the well known task priority based framework, extended to also encompass scalar inequality constraints. Experimental trials supporting the proposed control strategy are presented. In particular, one of the preliminary pool trials is presented, followed by the sea trials of the final demo of the project, carried out in Port Soller, Majorca during October 2012.