Assisted guidance system for Micro ROV in underwater data gathering missions

Recent years have seen an increasingly interest by the scientific community in the realization of minimally invasive technologies and tools for carrying out activities like exploration and intervention in the marine environment. This paper will describe the design and realization of a novel assisted guidance system for a Micro ROV, which is part of a more complex robotic system, together with a large ROV. Within this framework, the smaller robot is employed as a mobile appendix of the larger one, while the latter acts as an actuated garage and a supply vessel of the first. During operations, the ROVs guidance systems are decoupled, that is the larger one works in station keeping or in path following, either automatically or under the supervision of an expert operator, while the smaller one is teleoperated by a pilot not necessarily trained. This structure allows scientists like marine biologists, archaeologists and oceanographers to operate directly the Micro ROV, combining their knowledge of the application domain with the ability of professional ROV pilots. The described robotic structure is potentially very efficient and versatile, but its realization implies the development of solutions which could support the Micro ROV untrained operators. For this reason, the present paper focuses on the description of an assisted guidance system for Micro ROV aimed at achieving the objective above. The system makes the Micro ROVs pilot keep the vehicle within a given range from the large ROV, by means of a reactive joystick. Generation of the reactive force is described, and the use of the assisted guidance system in performing underwater data gathering missions of an archaeological site is discussed.