Automation of vessel slamming avoidance processes

Abstract

The object of the research is the processes of slamming automatic avoidance when the vessel is sailing in a storm. During stormy sailing, the vessel is subjected to external influences from wind and waves, which lead to strong dynamic loads on the hull, increase in heel and trim angles, flooding of the deck. The vessel's speed decreases, its controllability deteriorates. Slamming is one of the most dangerous phenomena in storm sailing. The appearance of slamming depends on many factors: the size and shape of the vessel's hull, the draft of the bow, the state of the sea, the vessel's course and speed. Slamming is characterized by impacts of the bow and the bottom of the vessel's hull against the water when moving towards waves, the length of which is approximately equal to the length of the vessel. Impacts are accompanied by body shaking, due to a sharp increase in the load on the bottom, and a slowly fading vibration. Hydrodynamic shocks on the bottom and general vibration are the reasons for the violation of the local and general strength of the hull. Slamming and other dangers of stormy sailing are the cause of strong psycho-emotional stress of boatmen, contribute to the accumulation of fatigue, which is a prerequisite for accidents. In the article, a method of automatic control of the vessel to prevent slamming was developed. The obtained results are explained by the use of an on-board computer, the construction of a dangerous area of slamming in on-board computer, the use of a gradient method of finding the optimal trajectory in time of the phase point output from the dangerous area, and the maintenance of the optimal trajectory by means of an automatic control system. The use of the developed method allows you to automatically avoid slamming, reduce the influence of the human factor on control processes, reduce crew fatigue, reduce the risks of losing the ship and cargo, and increase the safety of navigation. The developed method can be used on vessels, provided it is integrated into the existing automated system of the on-board computer to solve the problem of automatic avoidance of slamming during stormy sailing