Trajectory tracking passivity-based control for marine vehicles subject to disturbances

In this paper we present a dynamic model of marine vehicles in both body-fixed and inertial momentum coordinates using port-Hamiltonian framework. The dynamics in body-fixed coordinates have a particular structure of the mass matrix that allows the application of passivity-based control design developed for robust energy shaping stabilisation of mechanical systems described in terms of generalised coordinates. As an example of application, we follow this methodology to design a passivity-based controller with integral action for fully actuated vehicles in six degrees of freedom that tracks time-varying references and rejects disturbances. We illustrate the performance of this controller in a simulation example of an open-frame unmanned underwater vehicle subject to both constant and time-varying disturbances. We also describe a momentum transformation that allows an alternative model representation of marine craft dynamics that resembles general port-Hamiltonian mechanical systems with a coordinate dependent mass matrix.