Adaptive sliding mode control for autonomous surface vessel

An adaptive sliding mode control law is presented and simulation is done for trajectory tracking of an underactuated autonomous surface vessel. The control law is developed by introducing two second order sliding surfaces, first in terms of surge tracking errors and the second in terms of lateral motion tracking errors. The resulting adaptive sliding mode control law guarantees the uniform ultimate boundedness of position tracking. The position and speed of the surface vessel need to measured. Several simulations are performed where the vessel follows straight-line trajectory and various kinds of disturbances exerted through the simulation.