Study On Course/Speed Control Of Ship With Waterjet Propulsion

With the development of the waterjet propulsion technology and the manufacturing techniques, there are more and more vessels including lots of types using waterjet as engine. Those vessels are used in the military field as well as a wide range of civilian areas applications. So the ship's waterjet propulsion control technology is gradually attracting the attention of the researchers in the field. Used the ship with waterjet propulsion as research object, This paper researches the ship course and speed control technology.Firstly, it studies the waterjet thrust-vector model and ship movment model. After analyzing the thrust factors, get the relation between the thrust and the ship speed vector and power rotate speed on the base of the law of conservation of energy and momentum theorem. Then analyse the effect of the waterjet nozzle angle and deflector to thrust. It gives the waterjet thrust-vector model. After analyzing the characteristic research of vessel dynamical and powe, it gives ship movment model.Secondly, used the waterjet thrust-vector model and ship movment model, analyse the surge force and turning moment lost caused by the change of the nozzle angle and power rotate speed. Get the relationship among the changes of ship motive radius, roll angle, speed and the differences of thrust and waterjet nozzle angle. Then it gives the nozzle angle though restricting the roll angle when ship turns safety.Thirdly, it research the dividable control of course and speed. the system is divided into speed control loop and speed control loop. And deal with the mutual coupling relationship between those systems as system interference, including the characters of nozzle turning and power rotate accommodating. Because they are mismatched uncertain systems, and the backstepping design method that has advantages in uncertain system, so it gives the controller combining the backstepping design method and sliding mode theory that realized the course control. And in speed control, combined the backstepping design method and dynamic inversion, it gives the controller to solve the difficulty of the calculative of the differential coefficient and realize the speed control. Then it research the compositive control of course and speed. Because the speed controller has no coordination with the course controller, so consider the two controllers together, and sum up them to the unified control model. Then discuss the unknown parameters and the limited interference separately, and design the controllers for them. Then design the compositive controller considering two factors together to realize the ship control. Aim at the compositive method of course and speed, and in order to resolve the difficulties to determine design parameters, and the complex differential coefficient of the virtual control value. Adopt sliding mode controller to solve the modeling uncertainties and interference. It decreases the number of the parameters and reduces the difficulties of confirming them. At the same time using integral filter in the dynamic control to reduce the calculative workload of the differential coefficient. At last using neural network to get the waterjet dynamic inversion of the surge force and turning moment, which reduces the system uncertainty of waterjet and advances the model veracity.Finally, it sumes up the work of the thesis and the innovations, and it discusses the next work.