Dynamic simulation of ship pilotage process risk based on cloud model

The safety of pilotage operation of ships in tidal ports is significantly affected by tides, and the multi-window pilotage operation is affected by many uncertain risks. In order to carry out effective ship pilotage risk control during multiwindow period, it is necessary to simulate the dynamic ship pilotage risk of multi-period to grasp the evolution law of process risk. Based on the analysis of ship pilotage task scenarios, risk factors in different stages of pilotage process is obtained. By acquiring the subjective and objective factors data of different sampling points in the pilotage process, the cloud model is used to carry out the risk modeling and dynamic simulation of multiperiod ship pilotage process. Aiming at the piloting process of a luxury cruise ship from Yangtze Estuary anchorage to Waigaoqiao designated berth, combining objective data and expert knowledge of sampling points, the risk of the piloting process during six tidal window period ships was simulated. The results show that the risk evolution of the ship piloting process as a whole shows the law of "bathtub curve", the risk of the ship piloting is higher in the initial and berthing period, and the risk value of the ship in the normal navigation stage presents a relatively low stable state. Among the six window periods, the overall risk is the highest in the period of " rapid rising ", and the lowest in the period of "high flat tide" and "low flat tide". The simulation results are consistent with the pilot's cognition of piloting practice.