Improving the navigational preparation of a bridge crew for entering/leaving a port, including activities in case of emergency

Abstract

Statistical analysis of the causes of ship accidents showed that 10 % of accidents are due to the influence of irresistible force, about 15 % are the result of technical imperfection and sudden failure of ship equipment, and the remaining 75 % account for the «human factor» regardless of the cause of the accident. A detailed analysis of the causes of accidents reveals that they are caused by the actions of individuals, dominated by organizational errors by a group of operators in the preparation and execution of the maneuvering control process. At the same time, there is a gap between the complexity of modern equipment and the psychological capabilities of the human operator as an element of the human-machine system. Analysis of accidents in the Bugsky-Dnestrovsky Liman Canal over the past 20 years has shown that 58.5 % of accidents occurred in the dark and under conditions of limited visibility. There were two causes of accidents: grounding and allision, 84.3 %; collisions, 28.8 %. This indicates the insufficient preparation of bridge crews for navigating the canal. This paper has considered a procedure of bridge crew navigation training for planning safe motion coordinates while entering/leaving a port along the trajectory points, as well as actions in case of a pre-emergency and techniques to predict it. The coordinates of the travel points are determined at the intersection of rectilinear segments of the recommended safe rectilinear path on a chart. It is a relevant task to use new methods of planning the path and controlling the movement along it, taking into consideration the area for maneuvering, maneuverable properties of the vessel, as well as external influences, for timely detecting the deviation of parameters from those planned. The calculation of the planned coordinates is performed for the center of gravity of the vessel for the characteristic points of the path of movement (the beginning and end of a turn, the onset of braking) and trajectory points (rectilinear segments of the path through 0.2 cables, and curvilinear sections through 10 degrees). Coordinates of the assigned path are represented in the form of the linear matrices of the path rectilinear and curvilinear sections. The navigational motion control system consists of the devices to automatically determine deviations from planned coordinates and decision support systems to correct deviations detected. The proposed method to plan and control motion was investigated by computer simulation, the test was carried out under natural settings. Their results showed that the calculated optimal assigned trajectory enables accident-free guidance of the center of gravity along the predefined path by ship’s control means and meets the established criteria of optimality. The proposed method could be used in the development of controls for automated vessels and is the only possible one for vessels with unattended operation