Research On Intelligent Decision-Making For Collision Avoidance In Multi-Ship Encounters

With the development of intelligent ship technology,ship intelligent collision avoidance technology has become the key to research.In the practice of ship collision avoidance,multiship encounters are common and complex,and fast and effective decision-making for collision avoidance is an important guarantee for the safe navigation of ships.This study takes the multi-ship encounters situation as the research object,considers the requirements of the International Regulations for Preventing Collisions at Sea(COLREGs)and good seamanship for collision avoidance actions,simulates the collision avoidance logic of seafarers,and uses the fast optimization ability of the optimization algorithm to establish a multi-ship encounters intelligent collision avoidance decision-making model,which meets the needs of real-time collision avoidance.The main work is as follows.(a)A simplified model of the multi-ship encounters situation is proposed.According to the collision avoidance logic of avoiding a group of ships,simulating the intelligence of seafarers,the concept of Group Ship is proposed.Using the cluster analysis method,the single target ships with similar course,speed,distance and bearing attributes are clustered into a group ship,and the model of the group ship is established.Based on the dynamic clustering analysis method,a simplified model of the multi-ship encounters situation is established to realize the dynamic simplification of the multi-ship encounters situation,reduce the number of calculation targets in the decision-making optimization algorithm,and improve the efficiency of ship collision avoidance decision-making.(b)A course alteration action matrix model is proposed.In addition to considering overtaking,head-on situation and crossing situation,the encounter situations in Rule 18(Responsibilities between vessels)and Rule 19(Conduct of vessels in restricted visibility)are also included in the study.The requirements of COLREGs and the good seamanship for collision avoidance actions are modeled,the intelligence of seafarers to judge the course alteration direction is simulated,and a multi-ship encounters course alteration action matrix model is proposed.The course alteration action matriecs in sight of one another and not in sight of one anohter are established respectively,and combined with the requirements of Rule 8(Action to avoid collision),the range of candidate solutions of the decision-making optimization algorithm is determined.The decision-making conforms to the COLREGs and good seamanship,and the decision-making efficiency is further improved.(c)The intelligent optimization algorithm of ship collision avoidance decision-making is studied.Based on artificial physics optimization(APO)algorithm,a decision-making model for ship collision avoidance is established,which is used for course alteration action and speed alteration action.Based on social emotional optimization algorithm(SEOA),a decision-making model for course alteration collision avoidance is established.A deterministic optimization algorithm DOA(Deterministic optimization algorithm)is proposed,and a DOA-based ship course alteration collision avoidance decision-making model is established.The simulation results show that the intelligent optimization algorithm APO algorithm and SEOA can be used for collision avoidance decision-making,and DOA is recommended for collision avoidance decision-making because of its higher efficiency.(d)A multi-ship encounters intelligent collision avoidance decision-making model is established.A dynamic monitoring and evaluation mechanism is introduced,the collision avoidance logic of the seafarers is simulated,and an intelligent collision avoidance decisionmaking model for multi-ship encounters is established.According to the category of the target ship’s action change(type A or type B),the necessity of updating the collision avoidance decision is judged,and a series of unnecessary collision avoidance actions of the own ship are avoided.Dynamic collision avoidance decisions comply with the COLREGs and in line with ship collision avoidance practices.The simulation results show that the decision-making method is reasonable and feasible.(e)The engineering practicability of the decision-making model is verified.Based on the V.Dragon 5000 ship handling simulator platform,the validity of the decision-making model is verified and analyzed.The results show that the research results can be used for ship collision avoidance practice.The multi-ship encounters intelligent collision avoidance decision-making model proposed in this study is reasonable,feasible,safe and effective.It expands new ideas for the research of ship intelligent collision avoidance technology,and has good engineering practical value.