Research on positioning operation control method of J-lay vessel

Ship mathematical model and environmental disturbance model of a J-lay vessel are built, the model of pipe horizontal forces and moment acting on the ship is built by catenary theory. In order to avoid the ship´s high frequency motion component disturbing the closed-loop control system, passive nonlinear observer is applied to estimate the vessel´s low frequency variables during positioning process. Ship positioning operation controller is designed by the acceleration feedback and PID control strategy with pipeline action as feedforward term. Simulation results are used exclusively to demonstrate the observer and controller with established model for J-lay vessel.