Simulation and preliminary experimental results on S-surface control of an autonomous underwater vehicle based on MOOS-IvP

Classic PID algorithm is sensitive to the net buoyancy in the underactuated Autonomous Underwater Vehicle (AUV) control, and can be particularly problematic in the environment where the density of the water changes. S-surface control is based on the theory of fuzzy control and the structure of PD control, which shall be able to handle the above case well. It also simplifies the design of the controller and can improve the performance of non-linear control. In this paper, we test a number of cases by simulations of an underactuated AUV, especially investigating the effects of buoyancy of the AUV and the ocean current on the control performance. Further, we implement the S-surface control algorithm on a small AUV platform using MOOS-IvP, and present a preliminary experiment in a lake. The results show that the S-surface control has better performance compared to the PID in the case that the net buoyancy changes.