Trajectory tracking control during offshore pipe-lay operation based on back-stepping sliding mode method

Pipe-lay operation is an important special operation coordinated with dynamic positioning system in ocean engineering, with trajectory tracking of pipe-laying being a kind of special uncertain nonlinear system output tracking issue. The relation of the desired trajectories of pipe and vessel was discussed firstly. The kinematic and dynamic model for the vessel and pipe forces was developed then. The back-stepping sliding mode method was adopted to design the controller in two steps with the sufficient condition of the stability given based on the Lyapunov function. The validity of the designed controller was certified by a case for simulation. An available method for describing and realizing the similar output tracking control was offered.