Navigation system with adaptive disturbances compensation for an autonomous underwater vehicle

Abstract

In this paper is presented an adaptive observer based on gain-scheduled principle as a core in the navigation system of an Autonomous Underwater Vehicle (AUV) moving in the horizontal plane. The estimated wave-frequency motions are removed from the measurements and the resulting smoothed signals are sent as feedback to the heading controller for horizontal motions control. As an important improvement, the adaptive capabilities are obtained setting the observer gains as function of the wave frequency, which represents the sea states. The wave encounter frequency is estimated using an algebraic approach with good results. Simulation results show an excellent performance of the observer and the resulting horizontal motioncontrol system of the vehicle.