AUV Robust Guidance Control*

The control of under-actuated underwater vehicles with coupled dynamics is a research of major interest, not only but mainly due to the large number of applications in the offshore industry. In a former work, authors developed a controller exhibiting desired robustness features, which unfortunately presented a poor performance in tracking activities. To tackle this problem, a two degree of freedom robust controller using an ℋ∞ mixed sensitivity approach was developed and guidance rules were added to face the impossibility of a straight control of position variables within the used optimal approach. Guidance was accomplished using a Line of Sight (LOS) for horizontal motions and a Fuzzy Logic rule for vertical motions. Three cases of the tracking were simulated, its results validated clearly the good conjunction of the robust control and guidance approaches used here.