Experimental results on smooth path tracking with application to pipe surveying on inexpensive AUV

This paper details the development aspects of a low cost AUV autonomous, designed for autonomous pipline inspections, describing: hardware, software and control aspects. The article details three of the mains stages of the project, that have been already achieved: (a) the simulation results of Lyapunov based path planning of torpedo shaped AUV on pipe searching; (b) the contruction details of dual torpedo AUV for pipeline inspection and (c) the experimental results when using the prototype in path following using the Line of Sight (LOS) algorithm. Pipeline searching involves a series of zig zag explorations of the area where the pipe is presumably located. The path following method is based on a combination of Lyapunov technique and PI controller acting over thruster and rudder on a torpedo shaped AUV, designed originally for Oceanographic purposes. The article also shows the hardware and software details of a new low cost prototype designed specifically for pipeline inspections. The new vehicle called AUVI (Autonomous Underwater Vehicle for Inspections) [8], is a dual torpedo with a different thruster configuration than the Cormoran, operating in a differential thruster mode. Finally, the article shows experimental results of the new vehicle, where a LOS is used to keep the vehicle describing an almost circular path. When the design of the vehicle is completed and a good model of the new vehicle is obtained, the Lyapunov technique will be tested at full depth as it was done for the Cormoran.