The Study About The Basic Design Of Small-sized Unmanned Surface Vehicles Used For Offshore Monitoring

The ocean covers more than 70% of the earth's surface and contains about 90% of life forms on the earth.They are one of the main sources of food,employment and economic income,as well as potential sources of unknown biological and mineral resources and sustainable energy.In the process of human development and sustainable utilization of marine resources,marine monitoring technology is an indispensable mean.The development of marine monitoring technology is of great significance.Traditional marine monitoring means include ship navigation,satellite remote sensing,coastal monitoring,ocean buoys and so on.However,each method has its own limitations.In recent years,with the rapid development of control technology,navigation and positioning technology,small-sized unmanned surface vehicle,USV,has become a major research focus of ocean monitoring technology.However,the offshore marine environment is complex,and due to its own scale,small-sized USVs themselves are prone to large scale movement in waves.This brings great difficulties to the design of small unmanned ship.At present,most of the research on small unmanned ship at home and abroad focuses on the measurement and control system,and the research on hull design is less.In order to solve this problem,this paper chooses the coastal small unmanned ship for ocean monitoring as the research object and carries out the basic design.The specific work includes:Firstly,this paper summarizes the research status of USV and related design theories at home and abroad,introducing several commercial USV products at home and abroad,and clarifying the shortcomings of current research.Secondly,the plan of USV is selected and designed in this paper.Referring to the existing excellent unmanned ship products and related research results at home and abroad,the main dimension parameters of hull are selected from the point of view of safety,economy and transportation;Several common hull design forms are summarized and compared from the point of view of hydrodynamic performance,with emphasis on the analysis of motion performance and resistance.The design with excellent performance is selected as the paper.The design scheme and the selection of sensors and hull materials were carried out by consulting the specifications.Thirdly,the motion performance of a small-sized USV in waves is analyzed and studied in detail.The motion response of USV with different layout schemes and spacing between hulls is calculated and analyzed by numerical calculation method,and the influence of layout parameters and spacing between hulls on the motion performance of unmanned ship is obtained.The motion response of unmanned ship in working and living sea conditions is calculated and analyzed,and the motion response of unmanned ship at different speeds and under different wave directions are given.Limit speeds under sea condition and survival sea condition are also recommended.Finally,the hydrostatic and stability curves of unmanned surveillance ship are obtained by using the method of variable displacement calculation,and the stability of unmanned ship at large dip angle is checked from the basic stability principle.The resistance performance of unmanned ship is predicted by using slender body theory,and the economic speed of unmanned ship under different working conditions is selected according to the results.