Early Warning For Collision Risk Of Ships In Construction Waters

With the water construction projects increasingly,the safety of ship navigation in construction navigable waters has attracted more attention from all walks of life.As restricted waters,compared with other ordinary waters,ships sailing in construction waters often face higher collision risk.In order to ensure the ships navigate in construction waters more safely,this paper explores and studies the early warning method of collision accidents of single ship in construction waters,and puts forward the early warning method of ship collision risk in construction waters based on the prediction of ship navigation behavior and the assessment of ship collision risk.The specific research work is as follows:(1)Summarize and analyze the collision risks of ship navigating in the construction waters,and through consulting domestic and foreign literature on early warning of water traffic safety,combine with the early warning theory,detennine the early warning process and range for collision risk of ship navigating in construction waters.(2)According to the early warning process,determine the prediction model of ship's navigation behavior firstly.The real AIS data of ship is used as data source to predict the four indexes,including course over ground,speed over ground,longitude and latitude.On the basis of the traditional Extreme Learning Machine prediction model,the sampling period is automatically adjusted by adding the threshold of ship's steering and shifting in the new model,so as to improve the prediction accuracy during the ship's navigation state changing.Compare with the common forecasting methods,it is proved that the forecasting effect of new model is better and the forecasting error meets the requirements of the early warning model.(3)According to the characteristics of navigable environment in construction waters,select the appropriate ship domain model.On this basis,taking the minimum encounter distance,the shortest encounter time,the ship speed ratio,the relative distance and the relative direction as the risk assessment indicators of collision,establish the risk assessment model of ship collision,and set the ship collision risk degree as the early warning value,and formulate the early warning criteria formulated.(4)Through the numerical example to prove the early warning model of ship collision risk in construction waters.Based on platform of MATLAB,design the static state and various encounter situation and conduct simulation.The experimental results show that the model can accurately predict the risk degree between ships and obstacles,which indicates that the model proposed in this paper has certain feasibility and validity.