The complex dynamic characteristics and changeable marine environment pose great challenges to the design of the unmanned underwater vehicle (UUV) controller. In practical application, the parameter of the controller will be fixed after frequent manual debugging, which is unable to adapt to the changes of the environment during the control. In view of the above problems, a parameter adaptive S-plane control method based on the reinforcement learning is proposed referring to the adaptive control idea. The adaptive control method is used to optimize and automatically tune the controller parameter under different environments. This method is trained by Q-learning algorithm. The optimal mapping between the input status and output action is sought through the self-learning mechanism of Q-learning. Simulation results show that the proposed method can adjust the controller parameter in real time with excellent control effect and environment adaptability.

The ship integrated power system combines the conventional propulsion system and power system in the form of electrical energy, representing the development of the ship power system. However, the harmonic wave, one of the main issues affecting the power quality of the ship integrated power system, will be generated by large amount of non-linear and power-electronic devices due to the greatly increasing electrical load on board. The reasons for the generation of the harmonic waves are firstly analyzed, and the possible hazards caused by the harmonic waves are then presented. Finally, several commonly used harmonic wave control methods are summarized, mainly including source suppression and system compensation. Simulation results and engineering application cases are presented to demonstrate the effectiveness of the main harmonic wave control methods. It can provide references for harmonic control of the ship integrated power system.

The components of the multi-point mooring system are analyzed and selected according to the characteristics of the ship type and the operation sea area, in order to meet the design requirement of refitting a LNG carrier to a FSRU and to ensure the safety of the follow-up operation of the FSRU. A time-domain coupling analysis is carried out for the refitted mooring system under the environments of wind, wave and current by using the mooring calculation software, resulting in the maximum force and maximum displacement of the mooring line and anchor under the various operation conditions. The results show that the refitted mooring line and anchor can meet the engineering requirement, and the hull can meet the strength requirement due to the better controlled hull displacement. The relevant conclusions can also provide references for the design of other similar projects.

Anchor system design will directly affect the navigation safety of ships. The high holding power (HHP) anchor is optimal choice because of its small weight and large grasping force. The characteristics of the different types of HHP anchors are compared. The anchor system design of the different types of HHP anchors is then analyzed for a bulk carrier. The design is finally verified by anchor pulling simulation. It can provide reference for the anchor system design of other large ships.