Research on nonlinear model predictive control technology for ship dynamic positioning system

As an excellent technology, model predictive control has become a more pleasing and popular research topic. In order to solve the higher precision control problem for the nolinear, uncertained and strong-coupled ship dynamic positioning system, this paper introduces the nonlinear model predictive control (NMPC) technology into this system based on lots of foregoing work about its linear application. Firstly, a 3 degree of freedom nonlinear mathematic model of dynamic position ship is established based on ship dynamics. Secondly, the model is simplified according to the demand of design of the controller. Then, in terms of the concept of the lie notation, a nonlinear model predictive controller is designed based on NMPC theory. The controller is judged to be a Positive definite one. Finally, a simulation experiment is carried out and the simulation results show that the designed NMPC controller is effective and satisfactorily for ship dynamic positioning system.