Autonomous Towed Vehicle for Underwater Inspection in a Port Area

This paper discusses an autonomous towed vehicle for underwater inspection in a port area, in which a sea current is so fast and complex. The autonomous towed vehicle has three different navigation modes; towed mode, autonomous mode and kite mode, to assure safe and reliable inspection in such a port area. An autonomous underwater vehicle (AUV) is employed as a towed vehicle to increase autonomy. In towed systems, it is important to monitor a towed force for preventing cable breaks and making use of it more efficiently since a towing cable plays an important role in transmitting electric signals and towing forces. In this paper, we propose a sequence for towed force estimation consisting of different navigation modes and control methods for it. In addition, the navigation control system of the autonomous towed vehicle is briefly described. Simulations to verify the towed force estimation and control methods are carried out and the results are discussed.