Research Of The Ship Collision Frequency Based On Improved IWRAP Model

As people attach more importance to the safety of navigation of ships and more and more construction of offshore engineering is under planning,it is of more and more importance to quantitatively assess the navigation risk of ships on frequently collide with ships and offshore engineering construction areas.Engineering defines risk as the product of the probability or frequency of unwanted events and the consequences of an accident.The study of ship collision frequency model is the precondition and basis of ship navigation risk assessment,and its accuracy will affect the quantification of ship navigation risk assessment.IWRAP(IALA Waterway Risk Assessment program)model is one of the most widely used and most effective ship collision frequency models.In order to make the model calculation more accurate,IWRAP model is studied in this paper.First of all,the influencing factors of the accident causal coefficient in IWRAP model are analyzed and summarized in order to obtain a scientific method of determination.Secondly,based on the advantages of Feynman model,the IWRAP model is improved by added to modeling of collision frequencies within the same type of vessel under the overtake situation and modeling of collision frequencies between various types of ships with same direction under the situation of encountering in turning point,the IWRAP model more comprehensive in order to model the collision frequency of the ship Calculated more accurately.In this paper,we use the modified IWRAP model to calculate the collision frequency at the intersection of Yangshan Harbor deepwater channel and Jinshan channel outside Yangshan Harbor to verify its accuracy.In this paper,AIS(Automatic Identification System)data of one cross section of Yangshan Harbor Deepwater Channel and two sections of Jinshan Channel from July 2014 to July 2017 were collected and divided into three groups by time.Since July 2014 One year for a group.The improved IWRAP model is used to calculate the annual collision frequency and annual average collision frequency.The accuracy of the model was verified by comparing the actual frequency of collisions in the study waters with the frequency of collisions using the IWRAP model.More accurate ship collision frequency prediction model can improve the accuracy of ship navigation risk quantitative assessment in order to better determine the risk of each waters and to propose countermeasures or provide a more scientific basis for the decision-making of water projects.