A Study On Ship Collision Avoidance Decision-making Based On Collision Risk Index

In the process of globalization, maritime transport has made a great contribution, while the number of ships at sea is rising, so the ship encounter rate will increase, and the probability of ship collision accidents will also increase, followed by the loss of life, property and the marine environment. Implementation of ship automatic collision avoidance, not only can reduce the impact of human factors, but also can avoid collision accidents to some extent. The ship collision avoidance decision-making is the key step for automatic collision avoidance. In this paper, we do some in-depth researches in the ship collision avoidance decision-making based on the model of ship collision risk index. The ship collision avoidance decision-making is the key of the automatic collision avoidance. After the paper has deeply researched it based on the model of the ship collision risk index, establish the model of ship collision avoidance decision-making. Details are as follows:(1) In the existing collision avoidance mathematical model for altering course, considering the handling characteristics of the ship, calculate the transfer, the advance and the target ship’s displacement during the process of altering operation and then get the value of DCPA when finished altering.(2) Establish membership function for DCPA and TCPA. Analysis the papers about the domain, the point of last minute action and the Arena, decide the boundary values of DCPA and TCPA. The boundary values of DCPA are the DCPA when finished altering at the point of last minute action and the safe distance of approach; the boundary values of TCPA are the TCPA when the ship come to the point of last minute action and the TCPA when the distance between the two ships is the Arena.(3) Analysis the papers about the ship collision risk index. Set the DCPA and TCPA for the fundamental variable quantity, and then establish ship collision risk index model.(4) Establish the mathematical model of ship collision avoidance for altering course. Using revised ship domain of Goodwin to calculate the safe distance of approaching (SDA); take SDA as DCPA when finished action, and then set up the relationship between the action time and the range of altering course; determine the distance between the two vessels to take action and the angle to alter.(5) Establish the ship collision avoidance decision-making system based on the ship’s collision risk index, in the platform of MATELAB 2010b. To put to test for head-on situation, overtaking situation and crossing situation, the results confirm that his system is effective and practical.