Control of underactuated marine crafts with matched disturbances

ABSTRACT

Stabilisation of marine craft in the presence of disturbances is important to many offshore activities. The process of stabilising a marine craft using the actuators is known as dynamic positioning, and is challenging for underactuated craft. In our work, we develop a robust dynamic positioning controller for an underactuated marine craft that ensures input-to-state-stability with respect to matched disturbances. Using the strict Lyapunov function approach of Malisoff and Mazenc [(2009). Constructions of strict Lyapunov functions. Springer-Verlag], we show that the proposed controller ensures uniform global asymptotic stability of the desired equilibrium when there are no disturbances. We also show that the closed-loop system is input-to-state stable with respect to matched environmental force and moment disturbances. Finally, we illustrate the performance of the proposed controller through simulations.

Keywords:

• Dynamic positioning
• marine control
• input-to-state stability
• strict Lyapunov functions
• underactuated system
• matched disturbances

Acknowledgements

J.K. and J.F. acknowledge continued support from the Queensland University of Technology (QUT) through the Centre for Robotics.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research is supported as part of a collaboration between the Defence Science and Technology (DST) Group, Australian Department of Defence and the Queensland University of Technology.