A Sensor Based Homing Strategy for Autonomous Underwater Vehicles

A new sensor based homing integrated guidance and control law is presented to drive an underactuated autonomous underwater vehicle (AUV) towards a fixed target, in 3D, using the information provided by an ultra-short base line (USBL) positioning system. The guidance and control law is firstly derived for the vehicle´s kinematics expressed as the time differences of arrival (TDOAs) measured by the USBL sensor assuming the target at the infinity, and then extended for the dynamics of an underactuated AUV resorting to backstepping techniques. The proposed Lyapunov based control law yields almost global asymptotic stability (AGAS) in the absence of external disturbances and is further extended, keeping the same properties, to the case where known ocean currents affect the vehicle´s dynamics. Simulations are presented and discussed that illustrate the performance and behavior of the overall closed loop system