MANEUVER FOR STOPPING THE SHIP IN A SET POINT BY ACTIVE OR PASSIVE BRAKING AND CONCIDERING THE CURRENT

Abstract

The article deals with the use of active or passive braking of a ship to stop it at a given point. To substantiate the relevance of the study, an analysis of the literature on the problem of ensuring the safe maneuvering of ships was carried out, in which the issues of theoretical and experimental studies of the turnability of ships, the adequacy of the existing models of turnability to the real process of turning the ship, as well as the development of a system of autopilot control of the ship's heading using the principles of fuzzy logic were considered. Considerable attention is paid to the development of an information system for simulating the movement of ships with complex dynamic models. The necessary analytical expressions are given that characterize the dependences of the time and the distance traveled to the stop of the ship on the mode of active and passive braking, which are required to solve the problem posed in the work. A formal description of the maneuver for stopping the ship at a given point by active and passive braking is obtained. This description makes it possible to determine the moment of engine stop in case of passive braking or the moment of its reverse – in case of active braking, provided that the ship is following a heading equal to the bearing to a given point. Cases of presence and absence of current in the area of ship maneuver are considered. In the case of the presence of a current, two stages of the ship's movement are considered: from the zero moment of time until the moment of the start of braking, when the speed of the ship is unchanged, and the second stage, from the moment of the start of braking until the stop of the ship, when the speed of the ship decreases. To take into account the flow during braking with an exit to a given point, two methods are proposed. The first one is at a constant flow angle with a lateral displacement relative to the programmed trajectory of motion. And the second – with a variable flow angle at zero displacement relative to it. A successful check of the correctness of the results obtained by simulation computer modeling of maneuvers for stopping the ship at a given point of braking, taking into account the current, has been carried out