Quaternion Feedback Regulation of Underwater Vehicles

: Position and attitude set-point regulation of autonomous underwater vehicles (AUVs) in 6 degrees of freedom (DOF) is presented. Euler parameters are used in the representation of global attitude. Three quaternion feedback controllers are derived based on vector quaternion, Euler rotation and Rodrigues parameter feedback, respectively. Global asymptotic stability is proven in the first and second case, while Rodrigues parameter feedback yields asymptotic stability. Keywords. Position regulation, attitude regulation, quaternion feedback, underwater vehicles. 1 Introduction Unmanned underwater vehicles (UUV) have become an important tool for undersea operations without divers. Most of them are remotely operated vehicles (ROV) via cable from a surface mother ship. Autonomous underwater vehicles (AUV) are freeswimming devices which carry their own energy source and automatically interact with the environment. Some applications of UUVs and underwater robotic vehicles (URV) are visual surv..