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Method for determination of crosswise hydrodynamic force and its moment in ship complex maneuvering Invention relates to control over ship course in complex maneuvering at mooring, dynamic position or drifting. Proposed method consists in that prior to performing complex maneuvering, ship rotates under effects of active control means, for example, lateral thrusting propeller. Note here that ship angular ω and spinning moment Mpr produced by lateral thrusting propeller are calculated. Angular speed ω and spinning moment Mpr are used to define hydrodynamic factor c2 and transverse component of hydrodynamic force Yβ, formed at ship hull in its motion with the help of log and formula: Yβ=Cyβ0,5ρυ2Fdp, here C yβ≅c2, ρ is water bulk density; υ is ship linear speed; Fdp is reduced area of centerline buttock. |
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Method of defining ship mathematical model hydrodynamic parameters Invention relates to navigation and can be used for forecasting ship manoeuvres. Proposed method comprises application of ship motion mathematical model and two fore and aft points F and A points, respectively, spaced apart over the centre plane length, Defining current coordinates of ship motion kinematic parameters in moving coordinate system ZX0Y to define current hydrodynamic parameters of ship mathematical model and to execute computer simulation of the basis of the latter. Moving coordinate system ZX0Y is related to the ship. Acceleration transducers are used to define in real time the current magnitudes of lengthwise, crosswise and angular accelerations of fore and aft points F (wfx1, Wfy1, ε) and A (wax1, Way1, ε) in fixed coordinate system X101Y1. Said magnitudes are used to define current magnitudes of ship motion kinematic parameters. |
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Determination method for dynamic parameters of marine movement mathematical model FIELD: ship navigation. SUBSTANCE: invention refers to ship navigation and can be used for forecasting the ship movements in the course of maneuvering. The fore and backward points are conditionally used. The fore and backwards points are located on the centerline plane of the ship. On a real time basis the coordinates of the fore and backward points are measured. Measurement of the coordinates is fulfilled with the help of the static shear stress receivers and with differential corrections. On the basis of the coordinate measurement results the current values of kinematic movement parameters are determined: linear speeds of the fore F (υf) and backward A (υa) points and their longitudinal (υfx, υax) and lateral (υfy, υay) components in the moving coordinates ZX0Y connected with the ship; longitudinal centre of the rotation (x0) in the moving coordinates ZX0Y connected with the ship; projection of the linear speed vector in the centre of gravity on the y axis 0Y (υy); linear speed of the ship centre of gravity (υ); curvature of the gravity path (R); angular rate of the ship (ω). The obtained results are used for calculation of the current values of the dynamic parameters of the marine movement mathematical model. On the basis of the mathematical model computer modeling is performed in order to forecast the ship movements in the course of maneuvering. EFFECT: improvement of the accuracy of forecasting of the ship movements in the course of maneuvering on the basis of an adequate mathematical model of its travel. 3 cl, 1 dwg |
Another patent 2531326.