Geoscience Reference
In-Depth Information
The ship moving on the dynamical sea surface is described by the theory of
automatic control equations. These equations are extended by hydrophysical cor-
relations re
ecting functional dependencies between the ship moving parameters
and characteristics of sea currents and turbulent
fl
flows. Complete series of equations
describing the ship-sea system dynamics has a set of parameters which determine
the state of this system. Methods for assessment of these parameters developed in
the experimental hydrophysics give in most cases averaged by time and space
values that does not correspond to the demand of ef
fl
cacy and do not give the
possibility to have in full measure the complex database for the ship management in
real time regime, for example, by means of their realization in the autopilot mode.
Speci
cally, this is important in zones of ports where calculation of safety condi-
tions for ship has to be operative.
Remote monitoring methods of sea surface in the aggregate with data processing
algorithms are characterized by responsiveness. The development of these methods
with reference to the sea navigation problems is one of the ecoinformatics tasks
(Krapivin and Thu 2001). The reception of initial information for the calculation of
ship velocity and course basing on the whole data received from navigation systems
and on remote sensing data is considered as experimental ecoinformatics task the
solution of which is realized by the choice of the most reliable information sources
and rational methods for its processing.
Moving or stopping ship is subjected by action of forces formed by complex of
processes taking place into the sea arising of which connects with the wind, tem-
perature gradients, water density variations, gravitation waves etc. Trajectory tasks
of the ship handling are divided into two classes. The
first class has local character
when the operative control of physical processes in the ship-sea system is needed.
These tasks are arisen in the connection with the necessity to prevent the ship
intense heaving or to decrease the yaw angle. In this situation, the measuring remote
sensing system is installed on the ship board. The second class of tasks is connected
with an assessment of sea state on long distances of ship course under information
security for its management systems. Generation of such information is possible by
using satellites,
flying laboratories or coastal systems.
The task is in the regulator design which is located on the ship provides optimal
control of the ship course basing on the receiving information about the sea state
and meteorological parameters. Since environmental parameters during the ship
moving are changing, the regulator must have adaptability function with time
interval that is less time between changes of environmental parameters.
The principal scheme for adaptive regulation of the ship control parameters,
using GIMS, consists in the determination of the ship location and assessment of
discrepancy in forecasting ship course basing on the data from on-board navigation
sensors and radio-navigation satellite systems. Correcting controlling parameters of
the ship moving course are calculated on the base of this discrepancy value. The
ship course warning interval is selected by the navigator depending on the real
situation or is optimized automatically if this decision is not taken.
The synthesis of the ship-sea systemmodel is the base of theGIMS technology use in
sea navigation. This model parameterizes the correlations between physical factors of
fl
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