Nonlinear control for autonomous underwater glider motion based on inverse system method

Autonomous underwater gliders are highly efficient, buoyancy-driven, winged autonomous underwater vehicles. Their dynamics are multivariable nonlinear systems. In addition, the gliders are underactuated and difficult to maneuver, and also dependent on their operational environment. To confront these problems and to design an effective controller, the inverse system method was used to decouple the original system into two independent single variable linear subsystems. The stability of the zero dynamics was analyzed, and an additional closed-loop controller for each linear subsystem was designed by sliding mode control method to form a type of composite controller. Simulation results demonstrate that the derived nonlinear controller is able to cope with the aforementioned problems simultaneously and satisfactorily.