Research On Nonlinear Control Of Waterjet Propulsion Surface Unmanned Naval Vessel

Surface unmanned boat of waterjet propulsion as new military platform can be equippedwith sensors,communication equipments and weapons,which has good feature of stealth,flexible operation,autopilot.which can be suited to perform quick detection, latency,manoeuver and other tasks in a variety of harsh environments. If the system is established, itwill remove obstacles at sea and setup a rapid sea lanes in future seawar, which will play anactive role.This dissertation is based on a research project and national natural science foundation ofChina(No:50909026), The thesis sepecifially address heading control, dynamic positioningand trajectory tracking control,which combine the mission of departure, closing to the targetand tracking target.The manoeuvring model of the waterjet propulsion unmanned boat are establish byMMG separation principle. Firstly, the fluid hydrodynamic characteristics are analyzed andhydrodynamic empirical computing formula are discribed. Then the alamarin_jet230of waterpropulsion math model of unmanned boat is also established and tested by comparison withexperimental datum.Finally the three degrees of freedom motion control model of waterjetpropulsion boat is given.In order to solve unknown upper bounds of disturbances, including the loss of the spraywater velocity, the longitudinal velocity and the changes of sea conditions during the mission.A robust adaptive sliding mode control with fuzzy self-tuning control approach is proposedfor ship course control. The parameters of the robust adaptive controller can be tuned byemploying fuzzy rules. The algorithm can be further simplied to a single input fuzzyself-tuning PID controller for easier engineering.The dynamic positioning problem of an underactuated surface vessel is addressed.Adiscontinuous control approach with two stage control laws switched on at given time isproposed based on the stability analysis of the transformed system with the aid of global fastterminal sliding mode method.In order to overcome the the persistent excitation problem indiscontinuous feedback control law, a new cycle time-varying state transformation is proposed,and a time-varying Lyapunov function can be easily to constructed to design a asymptoticstabilization control law for underactuated surface vessel.Trajectory tracking of underactuated surface vessel has proved to be a challengingproblem. After global diffeomorphism and feedback transformations, A curve control lawwithout distburbances is designed by the application of Lyapunov direct method and backstepping strategy. Furthermore, In order to slove constant environmental disturbancesduring tracking, A adaptive robust trajectory tracking control method which is based ondisturbances compensation is proposed.