Investigations on the dynamic station keeping of an underactuated autonomous underwater robot

Abstract

In this paper, a new method for station keeping of underactuated underwater robots in the presence of underwater currents and external disturbances is proposed. Three small additional thrusters are introduced for station keeping purpose which are less power consuming and are actuated only during the station keeping mode. These thrusters are located in such a way that the generated forces and torque are enough to compensate the underwater currents and disturbances. Station keeping thrusters' locations and directions are nearly optimized using Taguchi's robust design method. The effect of additional thrusters on robot tracking control performance is investigated and the results are presented. The effectiveness of the proposed configuration is demonstrated with the help of hardware-in-the-loop (HIL) simulations using an experimental autonomous underwater robot. The underwater current effect on the corresponding motions of the underwater robot is investigated and some interesting phenomena with respect to different underwater current amplitudes and directions are observed. Robustness of the proposed configuration is also investigated. © 2011 DAAAM International Vienna.