First Trial Results of ATES: Advanced Telerobotic System for Underwater Complex Operations
Authors: Brambilla M. , Maddalena D. , McCavanagh G. 
Published: October 2008

This paper describes the purposes, the technical approaches, and the first trials results of the ATES system. This R&D project aims at the improvement and the adaptation of innovatory robotic technologies and the integration of these technologies with an industrial ROV to set up an advanced underwater telerobot capable of efficiently replacing divers in performing a large spread of complex tasks related to the offshore industry, such as construction support, platform maintenance, subsea plant servicing, etc. The key robotic technologies considered are: supervisor control, scene reconstruction and telepresence. The supervisory control includes also the manipulator force control while the scene reconstruction techniques based on computer vision are able to compensate for the ROV motion during manipulation. To evaluate the technical and economical validity of the system, extensive trials have been carried out, where typical submerged scenario comprising a real node and a well head mock-up has been used. This paper reports the first results of this trial activity demonstrating the improvements in complex task execution and accuracy and the feasibility of such tasks even with a loose docking. The tests are still going in protected water using a work ROV.

INTRODUCTION

The present application scenario of underwater interventions includes many tasks which require high accuracy and/or are characterized by high complexity of execution. For instance tasks such as construction, platform NDT (Non Destructive Test) inspection, plant servicing, etc. can require high accuracy in thepositioning and motion of tools with respect to the environment and sometimes even a careful control of the interaction force between arm and environment.

These tasks are currently carried out with high difficulties using the available master-slave manipulation technique. With this approach the operator monitors the actual task execution through remote TV cameras mounted on a ROV (Remote Operated Vehicle) while controlling with a master arm the remote slave manipulator fitted with suitable tools.

It is generally recognized that a great skill by operator is required to carry out most of the tasks. Very often the operator uses a "trial and error" approach which is very time consuming and even unsafe for the objects to be manipulated or the tools. Furthermore some tasks arepractically not feasible.

To overcame such limitations, Saipem S.P.A. in cooperation with Tecnomare S.p.A. and Sonsub 1 started the project ATES, Advanced TElerobotic System. The project aims at the improvement and finalization of existing innovative key robotictechnologies already developed at laboratory level by Tecnomare in previous projects. and their integration with an existing suitable ROV to set up an advanced underwater telerobot whose purpose is to efficiently replace divers in performing a large spread of underwater complex industrial tasks related to the offshore industry.

The work related to the ATES project constitutes a further significant development of underwater robotic technologies namely.

(Available In Full Paper)

To demonstrate the technical and economic validity of the system, extensive trials in laboratory (both dry and in water tank) have been carried out. Furthermore trials in protected water are ongoing on the first system prototype.