A novel adaptive fuzzy design for path following for underactuated ships with actuator dynamics

This paper discusses the problem of linear path following for an underactuated surface ship with rudder actuator dynamics under external disturbances. By employing T-S fuzzy system as approximator of those unknown nonlinearities, a robust adaptive fuzzy controller is proposed by fusion of ldquodynamic surface controlrdquo(DSC) approach with ldquominimum-learning-parametersrdquo(MLP) algorithm for the investigated ship model. With only one parameter updated on line for each subsystem in the proposed algorithm, both substantial problems of ldquodimension curserdquo and ldquoexplosion of complexityrdquo are circumvented, so the algorithm is convenient to implement in applications. Additionally, the possible controller singularity problem can also be removed and the stability of the closed-loop system is guaranteed. Simulation results on an ocean-going training ship dasiaYULONGpsila, belonging to Dalian Maritime University, are presented to validate the effectiveness of the proposed algorithm.