Modeling And Simulation On Controllable Pitch Propeller Propulsion Plant Of Offshore Engineering Vessel

In this paper,the "offshore oil 681" ship was taken as the research object.Then its propulsion system was modular modeled and optimized by using the Matlab/Simulink as modeling and simulation platform.The paper attempts to introduce Active Disturbance Rejection Control(ADRC)into the control of ship propulsion system,which could improve the control quality and control accuracy effectively,especially in harsh environments.ADRC inherits and develops the advantages of the classic PID control and compensates for its inherent defects.It is a viable implementation plan to control the speed of main propulsion diesel engine and pitch angle.First,the mathematical model of the ship propulsion system is established.The characteristics of ship-machine-propeller coordination are analyzed and the system model is simplified reasonably according to the ship technical documentation.The simplified model of the system include the diesel engine system,the propeller subsystem,mathematical model of the thruster,control system model and external disturbance model.Secondly,design and implement the main engine governor and pitch regulator after researching the theory and algorithm of ADRC.In-depth study the implementation and function of the three main part of ADRC,which are tracking differentiator,extended state observer,nonlinear state error feedback and achieved by S-function.Then,design the governor and pitch regulator based on ADRC according to their working characteristics and control characteristics respectively.Finally,the main controller of marine propulsion system is designed and implemented based on the basic theory of fuzzy control and the parameters of the fuzzy controller are optimized by particle swarm optimization(PSO).The simulation of the speed of the ship is carried out.And the experimental results showed that the fuzzy controller optimized by PSO is better than the conventional fuzzy controller in terms of immunity and fastness which can improve the maneuverability of the offshore engineering ship greatly.