POSITION AND ATTITUDE TRACKING OF AUVS - A QUATERNION FEEDBACK APPROACH

A position and attitude tracking control law for autonomous underwater vehicles (AUV's) in 6 degrees of freedom (DOF) is derived. The 4-para meter unit quaternion (Euler parameters) is used in a singularity-free representation of attitude. Global convergence of the closed-loop sys tem is proven. In addition, several 3-parameter representations in ter ms of the Euler parameters are discussed with application to the same control law. These schemes contain singularities, and only local conve rgence can therefore be proven. The proposed control scheme is simulat ed with Euler parameters and Euler angles.