Burmaka I. Development of the theory and methods of external vessel’s operation in a situation of a risk of collision

The paper describes the principles of forming of vessels’ collision avoidance of elementary group of vessels, based on the principle of process control of vessel divergence, methods of assessment of close-quarters situation, choice of divergence maneuver and domain form of inappropriate positions. The possibility of forming of three types of domains is shown: the domain of invalid data of courses of the elementary group of vessels, the domain of invalid data of speeds of the elementary group of vessels, the domain of invalid data of courses of one vessel and speeds of another vessel. The analytical description of the system of prevention of vessels’ collision has been conducted, where the domain of round form is used. The analytical expressions of three types of domains limits of invalid data has been obtained. Computer algorithms of forming and graphic display of all types of domains has been developed, their use for the choice of safe strategy of vessel divergence by the change of parameters of motion of both vessels is shown. The processed questions of taking into account of vessels’ dynamics and navigational dangers at forming of domains of invalid data of motion parameters and calculation of their scopes with the application of different dynamic models of turning motion of the vessel taking into account their inertia-stopping characteristics. The method of taking into account the navigational dangers has been obtained at the choice of divergence maneuver by the domains of invalid data of vessels’ motion parameters, which foresees the change of course of one or both vessels. The cases of dangerous close-quarters situation of a group of more than two vessels and methods of choosing safe divergence maneuver in such cases are considered in the paper. The question of determination of the optimum vector of external operation of a group of vessels which dangerously approach by the minimum alteration of their courses is explored. The collision prevention of ships whose domains have elliptical, rectangular and complex forms, are investigated in paper and analytical expressions for maximum allowed distance of approach from the parameters of the approach situation and of safe domain forms are obtained. The procedure of the domain formation of invalid data of vessels’ motion is developed and collision prevention using elliptical and complex domains. In completion of paper the results of verification of accuracy of the dissertation paper results represented, for which the simulation computer program consisting of two basic modules which provide the choice of divergence maneuver by one of the developed methods for a given situation of dangerous close-quarters situation and reproduction of the chosen divergence maneuver, resulting in the conclusion about its accuracy was designed. Keywords: safety of navigation, prevention of vessels’ collision, external operation, analytical methods of prevention of vessels’ collision, vessels’ divergence maneuvers with the common change of their motion parameters, domains of invalid data.