ABSTRACT
This chapter develops a nonlinear adaptive fault-tolerant control strategy to force an underactuated ship with thruster redundancy and to follow a predefined path, despite the presence of unknown system parameters and environmental disturbances induced by wave, wind and ocean current. The techniques involved in the design and analysis include using the backstepping, parameter projection techniques and a traverse function. The control of underactuated systems with nonholonomic constraints has received vast attention from the control community over the past few decades. Typical examples for this type of systems include nonholonomic mobile robots, underactuated ships, underwater vehicles and vertical take-off and landing aircrafts. The design method developed for chained-form systems was adopted for underactuated ships through a coordinate transformation. A global robust adaptive controller was proposed to force an underactuated ship to follow a reference path by considering both constant and time-varying disturbances.
