Hain Tun

Functioning of intellectual systems (IS) a safety of navigation is connected with the continuous control of behaviour of a vessel over a various level of external indignations [1] ? [15]. Alongside with situations which became typical at studying dynamics of a vessel on excitement, there is one more situation connected with continuous deterioration of initial stability. The effect of decrease in stability is to the greatest degree shown at courts with the S-shaped diagram of stability at movement on passing excitement. Presence of such diagram at influence of large packages of irregular waves causes sharp deterioration initial metacentric heights that leads to crankness of a vessel. The phenomenon of crankness is often observed in practice of operation. Cases of the heavy failures connected with sharp deterioration of stability on excitement are known. In experiments with model of cargo steam-ship on irregular excitement the sharp deterioration of stability led crankness of a vessel during passage of top of a wave through it middle has been established. It promoted occurrence of onboard rolling of the big amplitude (up to 30 degris and more), much resonant amplitude exceeding size (nearby 23 degris) at position of a vessel by a log to excitement. On the basis of carried out research it is possible to draw the basic conclusions defining features of dynamics of a vessel in conditions periodically changeable initial metacentric of height. At movement on passing excitement of courts from S-shaped chart stability at the certain values initial metacentric heights the phenomenon of crankness leading occurrence of an extreme situation (an opportunity of overturning owing to displacement of a cargo, etc. factors) is marked. Occurrence and development of an extreme situation is connected with intensive external indignations from packages of large waves in structure of irregular excitement and are defined by features of dynamics of interaction, geometrical and hydrodynamical characteristics of a vessel. Depending on structure run into excitements are possible various modes of oscillatory movement of a vessel on excitement. The first mode represents the three-stable system formed during periodic decrease metacentric of height. The second mode - bistability system, at which vessel tilts on right, or on the left board. The analysis of probability of overturning is carried out by a method functional actions. The lead analysis of data of modelling has allowed to formulate criterium the parities describing occurrence of the considered extreme situation. These data used as the control of dynamics of a vessel over excitement by means of onboard IS, functioning on the basis of the given dynamic measurements, mathematical models and the structured know-ledge base.