Adaptive control of an autonomous underwater vehicle: experimental results on ODIN

This paper presents a six-degrees-of-freedom controller for autonomous underwater vehicles. The control algorithm is adaptive in the dynamic parameters that are poorly known and time-varying in the underwater environment. Moreover, the proposed control law adopts quaternions to represent attitude errors, and thus avoids representation singularities that occur when using instead Euler angles description of the orientation. The adaptive controller has been successfully implemented and experimentally validated on omni-directional intelligent navigator (ODIN), an autonomous underwater vehicle that has been designed and built at the University of Hawaii. The experimental results demonstrate the good performance of the proposed controller within the constraints of the sensory system.