Drift Model For Free-form Object At Sea

With the development of economy and the prosperity of shipping industry, the scale of seagoing vessels in China has gotten sharp rise not only in quantity but also in tonnage, the number of people engaged in shipping transportation increases rapidly and sea activities are ever more frequent simultaneously. Now marine transport has become the main type of shipping transport in our country’s foreign trade. However, the complicated and varied marine environment often leads to the happening of perils, which will threaten the safety of lives and property and causes incalculable marine environmental pollution. How to fix the position or region of distress targets quickly and accurately is the key in successful rescue. This thesis will start by analyzing factors that influence the draft of free objects at sea, managing for building models of free objects at sea, to provide theoretical basis and reference for rescue unit making decision, then improve sea rescue efficiency.This paper simplifies objects’motion as superposition of general currents and wind-induced drift motion on the basis of analyzing factors that influence the draft of free objects at sea. There are many factors that have influence on object drift, including wind, current, wind current, the type of flotage and the ratio of immersion and so on, but primarily are wind, current,wind current and tidal stream. When establishing drift model, assuming knowing last distress position of the drift object, influencing factors are decomposed into component U (X-axis) and the north-south component of V (Y axis)and using the integral equation can be calculated drifting objects coordinate at any time. Finally, crafting programming to build drift trajectory model, and use the GUI function of Matlab to write a demonstrating computer interface about drift trajectory model of flotage at sea, realizing drift model’s function visualization.This paper verify preliminary the drift model by living example happened in Bohai Bay, the final result basically corresponds with physical truth, showing that the searching area determining model at sea built in my thesis can mainly meet the demand of searching and rescuing at sea.