Investigation Of Model Predictive Control On Waterjet Propulsion Vessels

Compared with propeller vessels,water-jet propulsion vessels have great advantages in maneuverability,rapidity and maneuverability.Today,the main direction of vessels’ research is to accomplish higher performance of water-jet propulsion vessels.In the other countries,water-jet propulsion technology and research started earlier than domestic researches,thus they have more technological advantages,especially in the domain of water-jet propulsion control system.In this paper,based on two coordinates and the MMG maneuverability equation,the control model of water-jet propulsion vessels is established.Experimental data and theoretical models are applied to identify formulas of vessels’ resistance,and the foreseeing map regression formula used to calculate the hydrodynamic coefficients is introduced.Finally,simulation results of vessels’ maneuverability experiment,turning test,are presented and vessels’ maneuverability is analyzed.The water-jet propulsion control system,including steering system and reversing system,is introduced,and the transfer function models of each parts are established through mechanism analysis.Subsequently,the transfer function model of water-jet propulsion control system is established.The parameters of the transfer function model are obtained by parameter identification.Considering about the condition of the real system,the multiple input and output and the trajectory design,a nonlinear MPC controller has been designed.In order to testify its effectiveness,a comparison about MPC and PID has been presented.It demonstrates that the MPC controller outperform the PID controller in set time and tracking accuracy.In order to obtain better control performance of the basic control layer,this paper designs a model predictive controller with an inner loop observer.In order to prove its tracking accuracy and anti-disturbance characteristics,the controller is compared with the PID controller.The comparison results show that the predictive controller outperformances the PID controller in tracking accuracy and anti-interference ability.In order to realize the connection between the motion control layer and the actuator layer in the ship control system,this paper introduces a power based thrust distribution strategy and then applied the strategy into the controller outputs.The thesis’ s subject is the motion control of water-jet vessel,including control of motion model,control of actuator and trust distribution.