Research On Track Of Surface Unmanned Surface Vehicle Based On Pod Propulsion

With the rapid development of the automatic control theory,computer technology and artificial intelligence,USV(Unmanned Surface Vessel)is the inevitable trend of ship development in the future.Although some progresses have been made in the researches of USV at home and abroad,most of these unmanned surface vessels are suitable for marine environments instead of inland waters.The small USV for inland waters,which has the characteristics including small size,high sensitivity,no casualties and etc.,is mainly used for search and rescue,emergency,cruise,measurement and other fields.Track control is the key technology for ship's autonomous navigation and further accomplishment of various tasks.It is very important and practical for the maritime sector to improve the service capability by studying the USV's intelligent track control system and realizing USV's autonomous cruise.Compared with the traditional propeller propulsion method,the pod propulsion has better maneuverability,higher propulsion efficiency.Furthermore,it is more suitable for the ships in inland water due to the smaller demand for layout space.The main research contents and achievements are as follows:(1)the establishment of the non-linear response mathematical model of the USV based pod propulsionIn this paper,the USV named iNav which is developed by our research group has been used for research.Firstly,the non-linear response mathematical model of ship based on pod propulsion with three-degree-of-freedom is established.Then,the parameters are identified by least squares recursive algorithm based on the data of USV's Z-type test and the cyclic test,which is the basis of next researches.(2)the design of the USV's indirect track control algorithm based on bipolar fuzzy controlAutonomous navigation is realized using indirect track control method and the combination of improved LOS guidance algorithm and bipolar fuzzy controlling method.The simulation results and the experimental data show that this controlling method is effective and feasible.(3)the design of the USV's indirect track control algorithm based on the variable universe fuzzy controlIn order to solve the contradiction between control precision and the number of fuzzy rules in fuzzy control,and to simplify the design procedure of controller,a variable universe fuzzy control algorithm based on fuzzy reasoning is used for the small USV's track control.By comparing the simulation results of these two methods on Matlab,it is shown that this method can automatically adjust the input field,at the same time,it can avoid the selection of the scaling factor model and related parameters,reduce the overshoot,so as to accomplish the task of track control.