A U-MODEL BASED NONLINEAR ADAPTIVE CONTROL FOR UNDERACTUATED MULTIVARIABLE UNMANNED MARINE VEHICLES

In this study, underactuated coupled nonlinear adaptive control for multivariable
unmanned marine vehicles platform were studied, designed, developed, and tested.
Designing a controller that is suitable for both surface and underwater unmanned
marine vehicle is challenging tasks due to unstructured marine environment, highly
nonlinear due to the hydrodynamics and parameters interaction plus with the external
disturbances. Coupled nonlinear adaptive control using U-Model based internal model
control (IMC) approach can be implemented to overcomes these challenges. IMC
approach offer a good disturbances rejection capability. The method implements
coupled nonlinear identification via U-Model which able to model the system with
minimum error. Then, the controller is formularised using Newton Raphson method
as a representation of the inverse of the U-Model.