Research And Design Of Straight-line Tracking Control Systems For Underactuated Ship

With the development of shipping business, ports are busier and busier and the requirements for the capabilities of ship control are higher; it needs higher control precision of ship control for dynamic orienting vessels which are used to explore sea oil, geography etc; The main existing ship's control systems include the direction or indirectly route manipulations, whose control performance and structure need approving. So, it is an important study for present main shipping countries to design ship control systems with steady control performance and high control precision by taking into account all the characteristics of the ship control systems.A detailed study on the existing results on the ship control systems design are carried out in thesis, and a straight-route vessel controller design method is proposed based on the underactuation and nonlinear features of the ship control systems. The main work and contribution of the thesis are as follows:1. The present worldwide studies of vessel control systems are introduced. The vessels'6 DOF (degree of freedom) dynamic equation which has the feature of underactuation is analyzed.2. The nonlinear mathematic model with 3 DOF (degree of freedom) for the vessel straight-route tracking control system is established, and grounded the route controller design procedures will based on the obtained system model.3. The underacutation vessel straight-route controller design method is presented based on the Lyapunov method and the backstepping techniques. The proposed method has solved the problem of the limitations that the first rocking angle speed couldn't be zero, and solved the problem of changing rudder usually for traditional vessel control systems and realized the straight-route tracking of vessels effectively.4. According to the hardware architecture of ARM embedding system, the GPS guiding system is introduced to measure the ship' real location information and designed digital vessel automatic rocker; in the design of the system, the multi-control methods with real action, direction and route are proposed by considering the real movements of vessels, also added the safety redundancy for the vessel control system.5. Finally, the work in this thesis is briefly summarized and some remarks on further improvement of the remote experiment system are also presented.