Study On Ship Collision Riskbased On Field Theory

With marine traffic becomes denser and ships turn to bigger, the loss and harm resulted from frequent occurrences of ship collision become more serious. Thus, how to avoid ship collision is one of significant topics in the field of maritime studies around the world. Although the hardware of Vessel Traffic Service has become highly integrate and intelligent, its support for ship collision-avoidance is far away from the level of overall monitoring the ship collision risk. Thus, a improved ship collision risk model is needed to utilize the abundant data resources to achieve the evaluation and overall monitoring of macroscopic ship collision risk at waters.For achieving the purpose above, a ship collision risk model based on space, called ship safety field model, is built by creative introduction of field theory. Firstly, through comparative analysis of studies on ship collision risk, a method which combines curve fitting and model analysis is referenced to structure the ship safety field model. Second-ly, a kernel density clustering algorithm called DENCLUE is used as construction algo-rithm of space function to establish the ship safety field model. The index system of the model includes decisive factors and impact factors.Next, the ship safety field theory is created in reference of electric field theory, including some important indexes, acting and energy theory resulted from theoretical derivation. The theory above can achieve parameter discussion of the ship safety field model, which discovers the analytic relationship between the impact factors and coverage index of model. Then, with systematic and quantitative analysis of impact factors, the non-liner function relation between impact factors and the coverage index of the model is established by radial basis function neural network (RBF network). Therefrom, the quantitative problem of model frontier is solved totally. In the end, the ship safety field are accomplished and applied at specific waters.The result shows that the ship safety field is able to explain ship collision and collision avoidance principle in physical aspect. A ship collision causing theory and collision avoidance decision rule are concluded. The theories above are able to, on the one hand, effectively discover and analyze the collision risk at waters, also reasonably guide the collision avoidance action, especially multi-ship collision avoidance action. On the other hand, these theories can achieve to evaluate ship collision risk of waters. The evaluation result provides scientific basis to marine traffic safety management.