STAR (Subsea Tools Application Research) design of a general purpose subsea torque tool for ROV or UUV

STAR (Subsea Tools Application Research) was an underwater technology development project to develop advanced tools and control techniques for remote subsea intervention in diverless operations. As part of the STAR project an all-electric torque tool control system for underwater operation was developed. Its mechanical and control system design is modular, allowing a ROV or AUV to perform a range of subsea tasks such as bolt tightening/slackening, drilling, stabbing and metering. An important feature of the design philosophy was its modular, hierarchical control structure. The hierarchical design and utilization of controller area network (CAN) technology made it possible to implement a sophisticated real-time control system. This paper gives an overview of the STAR project, technical details of multilayer control system and its communications structure. Details of the testing procedures, and application areas are also discussed.