Design And Simulation Of 400kN·m Rudder Hydraulic System

The electro-hydraulic steering gear is the most extensive applied in the ship rudder system.Many advantages of the electro-hydraulic steering gear prompt its popularity.Its hydraulic control system is also one of the very important systems of ship motion control.The ship motion characteristics are disturbed by the wind, wave and current flow except for closely related with the dynamic characteristics of rudder system and navigation conditions.So the hydrodynamic load and disturbation of rudder system are very complex when the ship is navigating.The paper founds on the technical requirements of some steering system.The models of steering system and course control system are set up through the design and analysis of steering system.The controllers are designed using the classical PID control theory,and its validity is testified by the simulationsand analysis.Firstly,the composing and state-of-the-art of the steering system are summarized through reading,analyzing and collating the references.The working principle of the steering system is analyzed,as well as the basic technical requirements and choice principles of hydraulic rudder.These are the reference to design the hydraulic rudder system.Secondly,the characteristics of different type rudder and ship type which applicable for are analyzed.Based on the constitution of pump-controlled hydraulic servo rudder system and performance requirements of some ship rudder system,the rudder type and mechanical construction are confirmed.The steering system is calculated and designed,and the hydraulic components are selected.Then the rudder hydraulic system is composed.It's the foundation of modeling and simulation.The displacement control system of the variable displacement pump and steering system are modeled through simplifying the rudder hydraulic control system.The transfer function model of the steering system is set up at the end.On the basis of transfer function model,the linear and nonlinear model of ship handling are set up through the analysis of automatic pilot functions and working principle of the heading control system.Analyzing the external environment disturb when the ship navigating,the model of external environment disturb and heading control system considering the external environment disturb are built.Finally,the displacement control system of variable displacement pump,the steering system and heading control system are designed with the classical PID control theory.And these controllers are testified by the simulations.It's showed through the simulating curves that the precision and stability will be decreased when the disturbance exists.But they will be satisfied with the performance desires when the systems are controlled by the designed PID controllers.