RU2501064C2 - Method of controlling ship trajectory - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: method of controlling ship trajectory employs current values of magnitudes and directions of linear velocity vectors $${\overline{\upsilon }}_F$$

of the head F point and $${\overline{\upsilon }}_A$$

stern A point. Vector directions are controlled based on the condition of their constant direction at a given point in a fixed coordinate system X₀0Y₀, specifically the vector $${\overline{\upsilon }}_F$$

during movement is directed towards the final given position of the head point of the ship F_K, and the vector $${\overline{\upsilon }}_A$$

during movement is directed towards the final given position of the stern point of the ship A_K; magnitudes are controlled by estimating the ratios of the given values of each of the magnitudes to the corresponding current values of said magnitudes; a control signal σ is generated from values of differences between current and given values of magnitudes and vector directions $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A.$$

EFFECT: high efficiency of using ship control equipment.

4 cl, 2 dwg

Description

The invention relates to navigation and can be used to automate the control of the trajectory of any type of vessel performing complex maneuvers, in particular with large drift angles.

There is a way to control the ship’s trajectory, for example, in dynamic positioning, which is based on determining the parameters of the aerodynamic force vector acting on the vessel using sensors measuring the direction and speed of the wind, as well as a mathematical model of the vessel, calculating the parameters of the total thrust vector of the propulsion complex of the vessel, the direction of which is opposite to the direction of the aerodynamic force vector, and the module is equal to the aerodynamic force modulus [1], [2], [7].

However, this control method has several disadvantages:

firstly, all external influences, except aerodynamic, are taken into account by the method of successive approximations, which requires the repeated determination of the values of their parameters according to the results of multiple misses when bringing the vessel to a given final position;

secondly, these misses are also possible due to the inadequacy of the mathematical model of the vessel used in the control system, since its parameters are not identified taking into account the current values of the hydrodynamic and aerodynamic parameters of the ship's hull, which tend to change even during the maneuver;

thirdly, repeated misses when reaching the specified end position reduce the efficiency of the ship’s control system, mainly due to the increase in energy costs spent on ensuring the ship reaches the specified final position;

fourthly, in order to ensure safety when performing certain maneuvers (mooring to the berth), the vessel does not fall into the specified final position, this method does not provide for this.

A known method for determining the hydrodynamic parameters of a mathematical model of a vessel’s movement, including the use of two forward F and aft A points with the SNA receivers installed in them to measure the coordinates of these points, determining the kinematic parameters of the vessel’s movement, and continuous identification of the vessel’s mathematical model (Pat . RF №2442718, publ. 02.20.2012). The invention improves the accuracy of predicting the movement of the vessel during maneuvering. This method is closest to the proposed and adopted as a prototype.

The aim of the invention is to increase the safety of the vessel performing complex maneuvers, as well as improving the efficiency of using the ship’s controls and, as a result, saving its energy resources.

и линейной скорости кормовой $${\overline{\upsilon }}_A$$

точек судна, а также их направления. Управление направлениями векторов $${\overline{\upsilon }}_F$$

и $${\overline{\upsilon }}_A$$

осуществляют исходя из условия их постоянной направленности в заданную точку в неподвижной координатной системе X₀0Y₀, а именно, вектор $${\overline{\upsilon }}_F$$

в процессе движения направлен в точку F_к, конечное заданное положение носовой F точки судна, вектор $${\overline{\upsilon }}_A$$

в процессе движения направлен в точку А_к, конечное заданное положение кормовой А точки судна. Управление модулями векторов $${\overline{\upsilon }}_F$$

и $${\overline{\upsilon }}_A$$

осуществляют путем оценки соотношений заданных значений каждого из модулей, рассчитанных методом компьютерного моделирования с использованием идентифицируемой в процессе движения математической модели судна [3], [4], [5], [6], с соответствующими текущими значениями этих модулей, определяемых с помощью акселерометров, установленных в носовой F и кормовой А точках судна.The control is carried out by adjusting the current values of the parameters of the linear velocity vectors of two points spaced along the length of the vessel located in its diametrical plane (DP), conventionally called bow F and stern A (Fig. 1). As adjustable parameters consider the modules of the vectors of the linear velocity of the nasal $${\overline{\upsilon }}_F$$

and linear feed speed $${\overline{\upsilon }}_A$$

points of the vessel, as well as their directions. Vector direction management $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A$$

carried out on the basis of the conditions of their constant directivity to a given point in a fixed coordinate system X ₀ 0Y ₀ , namely, the vector $${\overline{\upsilon }}_F$$

in the process of movement it is directed to the point F _k , the final predetermined position of the bow F of the vessel point, vector $${\overline{\upsilon }}_A$$

in the process of movement it is directed to point A _k , the final predetermined position of the stern A point of the vessel. Managing Vector Modules $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A$$

carried out by evaluating the ratio of the set values of each of the modules calculated by computer simulation using the mathematical model of the ship identified in the process of movement [3], [4], [5], [6], with the corresponding current values of these modules, determined using accelerometers installed in the fore and aft A points of the vessel.

и $${\overline{\upsilon }}_A$$

. С помощью акселерометров определяют текущие значения векторов $${\overline{\upsilon }}_F$$

и $${\overline{\upsilon }}_A$$

и полученные данные используют для формирования управляющего сигнала σ для движительно-рулевого комплекса (ДРК) судна. Таким образом, повышение эффективности работы систем управления судном позволяет уменьшить количество пробных выводов судна в заданную конечную позицию и тем самым уменьшить количество циклов работы ДРК судна и, как следствие, соответственно уменьшить энергетические затраты.In the inventive method of controlling the trajectory of the ship, the efficiency of the ship’s control systems is determined by a decrease in the number of attempts to bring the ship to a predetermined final position (i.e., misses). This effect is achieved due to the constant identification of the mathematical model of the vessel (a common feature) and its use to determine the given values of the vector modules $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A$$

. Using accelerometers determine the current values of the vectors $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A$$

and the obtained data is used to generate the control signal σ for the propulsion-steering complex (DRC) of the vessel. Thus, increasing the efficiency of the ship’s control systems makes it possible to reduce the number of test leads of the ship to a given final position and thereby reduce the number of cycles of the ship’s DRC and, consequently, reduce energy costs accordingly.

The essence of the method of controlling the trajectory of the vessel is illustrated by the drawings presented in figures 1, 2, and is as follows.

The given final position of the points F _k , A _k and G _k (center of gravity) (Figs. 1, 2) in the fixed coordinate system X ₀ 0Y ₀ is determined by their coordinates, i.e. F _to (X _0Fk , Y _0Fk ), And _to (X _0Ak , Y _0Ak ), G _to (X _0Gk , Y _0Gk ). The coordinates of the initial position of the points F _n (X _0Fn , Y _0Fn ), A _n (X _0An , Y _0An ) G _n (X _0Gn , Y _0Gn ) are determined using the satellite navigation system (SNA), also determine the current values of the coordinates of these points in the process of maneuvering F (X _0F , Y _0F ), A (X _0A , Y _0A ), G (X _0G , Y _0G ). To determine the coordinates of these points using the SNA, the receivers are installed at two points: bow F and stern A, the coordinates of the third point G are determined by calculating its position relative to bow F and stern A points. If the distance from point F to point G is equal to l _F (Fig. 2), and from point A to point G is equal to l _A , then the current values of the coordinates of point G, taking into account the current values of the coordinates of points F and A, will be equal to:

$$X_{0G}=\left[X_{0F}+\left(l_F/l_A\right)X_{0A}\right]/\left[\mathrm{one}+\left(l_F/l_A\right)\right];\left(\mathrm{one}\right)$$

$$Y_{0G}=\left[Y_{0F}+\left(l_F/l_A\right)Y_{0A}\right]/\left[\mathrm{one}+\left(l_F/l_A\right)\right];\left(2\right)$$

The value of the planned time of the ship’s transition from the initial position to the final position Δt = t _to -t _n (t _n is the time the ship maneuver begins, t _to is the time the ship arrived at the given final position) is determined by computer simulation of the planned maneuver of the ship from the initial position to the final using the identified mathematical model of the vessel and taking into account the parameters characterizing environmental factors in the area of the maneuver. In this case, it is enough to calculate the permissible speed of one point of the vessel, for example, its center of gravity (CT) on the path G _n G _to or any other point on the vessel lying in its DP, according to Fig. 1, for example, the bow point F on the path F _n F _to or feed point A on the way A _n A _to . In the future, the Δt value averaged out of three can be used according to the results of its determination for each of the indicated points.

Given that all points should be viewed in a predetermined end position at the same time, to determine the set of initial values modules vectors linear velocities dots G, F, A, namely, υ _gH, υ _FH, υ _An use dependence

$$\Delta t=\left(G_n{G}_{\mathrm{to}}/\upsilon G_n\right)=\left(F_n{F}_{\mathrm{to}}/{\upsilon }_{Fn}\right)=\left(A_n{A}_{\mathrm{to}}/\upsilon A_n\right),\left(3\right)$$

where from:

$$\upsilon G_n=G_n{G}_{\mathrm{to}}/\Delta t;{\upsilon }_{\text{F}}{}_{\text{n}}=F_n{F}_{\mathrm{to}}/\Delta t;\upsilon {\text{A}}_{\text{n}}=A_n{A}_{\mathrm{to}}/\Delta t.\left(\mathrm{four}\right)$$

и $${\overline{\upsilon }}_A$$

корректируют исходя из условия равенства их нулю в момент выхода точек F и А в заданное конечное положение F_к и А_к соответственно. Для этого определяют прогнозируемое время выхода точек (F, A, G) в планируемое конечное положение (F_к, А_к, G_к) и вычитанием значения текущего времени из значения прогнозируемого времени рассчитывают временной интервал, необходимый для уменьшения скоростей движения точек F и А до нулевого значения. Методом компьютерного моделирования с использованием идентифицированной математической модели судна определяют заданные на данный момент времени значения модулей векторов скоростей $${\overline{\upsilon }}_F$$

и $${\overline{\upsilon }}_A$$

.In the process of the vessel's movement to the final position, the given values of the modules of vectors $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A$$

correct on the basis of the condition that they are equal to zero at the moment the points F and A exit at a given final position F _k and A _k, respectively. To do this, determine the predicted time for the points (F, A, G) to reach the planned end position (F _k , A _k , G _k ) and by subtracting the current time from the predicted time, calculate the time interval necessary to reduce the speeds of the points F and A to zero. By the method of computer simulation using the identified mathematical model of the vessel, the values of the moduli of velocity vectors specified at a given time are determined $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A$$

.

, $$F\left({\overline{\upsilon }}_F\right)$$

и $$A\left({\overline{\upsilon }}_A\right)$$

в начале маневра и в течение всего периода его выполнения определяют из условия постоянной направленности соответствующего вектора в соответствующую конечную точку. Например, в процессе движения судна из начального положения в конечное отклонение вектора скорости точки $$F\left({\overline{\upsilon }}_F\right)$$

от линии, соединяющей текущее положение точки F и ее конечное положение F_к, должно иметь нулевое значение. В процессе выполнения маневра ведут постоянный пересчет заданных значений направлений векторов $${\overline{\upsilon }}_G$$

, $${\overline{\upsilon }}_F$$

, $${\overline{\upsilon }}_A$$

.The given directions of the point velocity vectors $$G\left({\overline{\upsilon }}_G\right)$$

, $$F\left({\overline{\upsilon }}_F\right)$$

and $$A\left({\overline{\upsilon }}_A\right)$$

at the beginning of the maneuver and throughout the entire period of its execution, it is determined from the condition of constant directivity of the corresponding vector to the corresponding endpoint. For example, in the process of a ship moving from its initial position to the final deviation of the point velocity vector $$F\left({\overline{\upsilon }}_F\right)$$

from the line connecting the current position of point F and its final position F _to , should have a zero value. In the course of the maneuver, they constantly recalculate the given values of the directions of the vectors $${\overline{\upsilon }}_G$$

, $${\overline{\upsilon }}_F$$

, $${\overline{\upsilon }}_A$$

.

и $${\overline{\upsilon }}_A$$

определяют с помощью акселерометров, установленных в точках F и А соответственно, при этом учитывают текущее значение курса судна ψ. Акселерометры измеряют продольные и поперечные линейные ускорения точек F(w_xF, w_yF) и A(w_xA, w_yA), а величины текущих значений модулей (υ_F, υ_A) и направлений (φ_F, φ_A) линейных скоростей точки F и точки А (фиг.2) рассчитывают на основании очевидных соотношений:Current values of modules and directions of vectors $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A$$

determined using accelerometers installed at points F and A, respectively, while taking into account the current value of the ship ψ. Accelerometers measure the longitudinal and transverse linear accelerations of the points F (w _xF , w _yF ) and A (w _xA , w _yA ), and the magnitudes of the current values of the modules (υ _F , υ _A ) and directions (φ _F , φ _A ) of linear speeds of the point F and points A (FIG. 2) are calculated based on the obvious relationships:

where β _F , β _A are the current values of the drift angles at points F and A, respectively.

и $${\overline{\upsilon }}_A$$

The magnitude of the control signal σ transmitted to the propulsion-steering complex of the vessel is formed from the magnitudes of the differences between the current and given values of both the modules and the directions of the vectors $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A$$

$$\sigma =k_{\upsilon F}\left({\upsilon }_{Ft}-{\upsilon }_{Fs}\right)+k_{\upsilon \mathrm{BUT}}\left({\upsilon }_{\mathrm{BUT}t}-{\upsilon }_{\mathrm{BUT}s}\right)+k_{\varphi F}\left({\varphi }_{Ft}-{\varphi }_{Fs}\right)+k_{\varphi A}\left({\varphi }_{At}-{\varphi }_{\mathrm{BUT}s}\right)\left(\mathrm{fifteen}\right)$$

here υ _Ft , υ _At , φ _Ft , φ _At , υ _Fз , υ _Aз , φ _Fз , φ _Az are the current (index "t") and given (index "h") values of the modules and directions of the velocity vectors of points F and A ; k _υF , k _υA , k _φF , k _φA are the gains.

To improve the accuracy of determining the values predicted by computer simulation and the parameters necessary for generating a control signal and, ultimately, to increase the safety of maneuvering, it is necessary throughout the entire maneuvering process to continuously identify the mathematical model of the vessel using known methods [3], [4], [5], [6].

Literature

1. Barakhta A.V., Yudin Yu.I. The structure and principles of dynamic positioning systems: Murmansk, Vestnik MSTU, vol. 12, No. 2, 2009. p. 255-258.

2. Petrov Yu.P., Chervyakov VV Stabilization systems for drilling ships. L .: Shipbuilding, 216 p., 1985 (Technique for the development of the ocean).

3. Yudin Yu.I. Using the maximum principle for parametric identification of a mathematical model of a ship / S.V. Pashentsev, Yu.I. Yudin // Science and technology of transport. - 2006. - No. 2. - S. 100-107.

4. Yudin Yu.I. Identification of parameters of a simulator model of tanker movement / Yu.I. Yudin, G.I. Martyuk // Navigation safety management and training of marine specialists SSN, 2004: materials of the 4th international conf. (Kaliningrad, June 9-10, 2004) / BFFSA. - Kaliningrad, 2004 .-- S.154-159.

5. Yudin Yu.I. Identification of the ship model - the most important element of the safety management of navigation / Yu.I. Yudin, RG Stepakhno // Management of safety of navigation and training of marine specialists: SSN, 2002: materials of the 3rd international. conf. (Kaliningrad, November 27-29, 2002) / BFFSA. - Kaliningrad, 2003 .-- S.274-283.

6. Eikhof P. Fundamentals of identification of control systems / P. Eikhof. - M.: Mir, 1975 .-- 432 p.

7. Operator Manual Kongsberg Simrad SDP. Dynamic Positioning System (Rel. 4.0 Update 5), p. 492, 2003.

Claims (4)

1. A method of controlling the vessel’s trajectory, including the use of two forward F and aft A points with the SNA receivers installed in them for measuring the coordinates of these points and based on them determining the parameters of the vessel’s movement, continuous identification of the mathematical model of the vessel, which differs by using the current values of the moduli and directions of the linear velocity vectors $${\overline{\upsilon }}_F$$

nasal F points and $${\overline{\upsilon }}_A$$

A feed point, while the direction of the vectors is controlled based on the condition of their constant directivity to a given point in a fixed coordinate system X ₀ 0Y ₀ , namely the vector $${\overline{\upsilon }}_F$$

in the process of movement directed to the final predetermined position of the bow of the ship point F _to , vector $${\overline{\upsilon }}_A$$

during movement, point A _{k is} directed to the final predetermined position of the stern point of the vessel, the modules are controlled by evaluating the ratios of the set values of each of the modules with the corresponding current values of these modules, form a control signal σ for the propulsion-steering complex from the values of the differences of the current and set values of the modules and directions of vectors $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A$$

. 2. The method according to claim 1, characterized in that the set values of the modules of vectors $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A$$

calculated by computer simulation using a mathematical model of the ship identified in the process of movement. 3. The method according to claim 1, characterized in that the current values of the vectors $${\overline{\upsilon }}_F$$

and $${\overline{\upsilon }}_A$$

determined using accelerometers installed in the fore and aft A points of the vessel. 4. The method according to claim 1, characterized in that the control signal is determined by the formula:
$$\sigma =k_{\upsilon F}\left({\upsilon }_{Ft}-{\upsilon }_{Fs}\right)+k_{\upsilon \mathrm{BUT}}\left({\upsilon }_{\mathrm{BUT}t}-{\upsilon }_{\mathrm{BUT}s}\right)+k_{\varphi F}\left({\varphi }_{Ft}-{\varphi }_{Fs}\right)+k_{\varphi A}\left({\varphi }_{At}-{\varphi }_{\mathrm{BUT}s}\right)$$

where
υ _Ft , υ _At , φ _Ft , φ _At - current values of the modules and directions of the velocity vectors of points F and A,
υ _{Fz, Az} υ, φ _Fz, φ _Az setpoints moduli and directions of the vectors F and A velocity points,
k _υF , k _υA , k _φF , k _φA are the gains.

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