Modeling and control of autonomous underwater vehicles

Autonomous underwater vehicles (AUVs) are free-swimming vehicles which travel underwater without real-time control by human operator. They are playing a crucial role in performing underwater tasks, such as deep sea inspections, long-distance, long duration surveys, oceanographic mapping and some military applications, including detecting, locating, and neutralizing undersea mines. Due to the complex underwater environment and the underactuated properties, AUVs present a challenging control problem. In addition, there are six degrees of freedom (DOFs) of the motion of an AUV and nonlinear coupling among them, making control design a challenging task. In this talk, we first present some recent results regarding the modeling and control of AUVs, including the nonlinear modeling, tracking control in 3D space for a fully actuated AUV, and the global K-exponential straight-line tracking in 3D space for the underactuated AUVs. For specific applications, including ocean sampling, mapping, mine sweeping and ocean floor survey, it is beneficial to carry out the missions through multiple AUVs cooperation for reasons such as increasing efficiency and service area, and providing redundancy in case of failure. Formation control of multiple AUVs is also presented in this talk, where we focus on the leader-follower formation control and the consensus based decentralized formation control.