A Supervisory Control System for the Automation of Subsea Tasks

Current trends in offshore oil and gas exploration and production are to introduce increased automation technology to replace human intervention using divers. This is driven both by the desire to reduce cost, and by practical considerations working at increasing depths down to 1000 meters. Unmanned underwater vehicle and manipulator systems play a crucial role in carrying out installation, inspection, maintenance and repair of platforms, well-heads, pipelines and subsea completion systems. In support of this, work is progressing in the Ocean Systems Laboratory at Heriot-Watt on integrated robotic systems implementing Supervisory Control of Remotely Operated Vehicle (ROV)/Manipulator systems for practical tasks such as automated connector insertions and Non Destructive Test inspection of welds. The systems involve use of hybrid position/force control of hydraulic arms coupled to control of the ROV, with associated Motion Planning, Task Planning and World Modelling of the environment. Sensing involves fusion and interpretation of data from high frequency sonar, laser striping and video sensors. The video shows footage of a recently developed Supervisory Control system employing Task Planning, World Modelling, Motion Planning and Hybrid Position/Force Control using a Slings by TA-9 hydraulic underwater manipulator. The tasks executed are trajectory following, guarded moves, grasping, and automatic mating of a subsea connector. ACKNOWLEDGEMENT This work was funded as the project Advanced Control of Manipulators in the 1992-94 managed program me Technology For Unmanned Underwater Vehicles by a UK government-industry consortium comprising: Marine Technology Directorate Ltd., agents of the UK Engineering & Physical Sciences Research Council, Mobil North Sea Ltd., Simrad Osprey Ltd, Health and Safety Executive Offshore Safety Division, Rockwater Ltd., Shell UK Exploration and Production, Defense Research Agency Maritime Division, Dept of Energy Offshore Supplies Office and Lockheed Aeronautical Systems Co. Their financial support and constructive criticism is gratefully acknowledged. Underwater Vehicle 2 Control Tests on ROBY, An Unmanned Underwater Vehicle Riccardo Bono, Massimo Caccia and Gianmarco Veruggio Consiglio Nazionale delle Ricerche, Istituto per 1’Automazione Navale Via De Marini, 6 16149 Genova, ITALY E-mail: max@ian.ge.cnr.it (Massimo Caccia)