A ship dynamic positioning control method and system for full-depth sea areas

Abstract

The present invention relates to the technical field of ship motion control, and specifically discloses a method and system for dynamic positioning control of ships in all-depth sea areas. The method comprises: S1: measuring the water depth in real time and calculating the depth-to-draft ratio in combination with the ship's draft; S2: updating a depth-adaptive hull dynamics model based on the depth-to-draft ratio; S3: calculating the real-time optimal control force based on the updated depth-adaptive hull dynamics model using an optimized quadratic index; and S4: performing dynamic positioning control based on the real-time optimal control force. The present invention enables the dynamic positioning system to be compatible with the control requirements of both deep-water and shallow-water operating areas, avoiding problems such as control drift and instability divergence caused by increased hull inertia, increased damping, and thrust loss in shallow waters.

Description

Technical Field

[0001] The present invention relates to the technical field of ship motion control, and in particular to a ship dynamic positioning control method and system for full-depth sea areas. Background Art

[0002] A ship's dynamic positioning system is a closed-loop control system that relies on its own propulsion system to automatically resist environmental interference such as wind, waves, and currents at sea, achieving precise control of the ship's position and heading. Traditional dynamic positioning (DP) systems are typically designed based on deepwater dynamics models. Their mass matrix, damping coefficient, and propeller thrust parameters are fixed values ​​after onboard commissioning and calibration, maintaining excellent control performance in deepwater areas (water depth and draft ratio greater than 3).

[0003] When a ship enters shallow waters, the following will occur: 1. The distance between the seabed and the bottom of the ship is too small, which hinders the flow of fluid around the hull, causing the additional mass to increase significantly, up to 2-3 times that of deep water areas, and significantly changing the inertial characteristics of the hull. 2. Due to the limited wave propagation, energy reflection and fragmentation, dissipation increases, and wave damping increases; at the same time, the flow velocity between the seabed and the bottom of the ship increases, the friction effect is enhanced, and the viscous damping also increases; thus, the ship's fluid damping coefficient increases nonlinearly, and the thrust required to correct control errors needs to be improved. 3. The thrust loss of the propeller in shallow waters can reach 40%. Without corresponding compensation, insufficient thrust often occurs. Many factors often cause traditional dynamic positioning control to be prone to positioning drift or even instability in shallow waters.

[0004] A Chinese invention patent application, publication number CN117215318A, discloses a method for controlling a dynamically positioned vessel in varying water depths. The method includes collecting the vessel's damping coefficient and propeller thrust coefficient under different draft conditions, and constructing a propeller model and a low-frequency motion model for the vessel. Although the patent calculates the damping coefficient and propeller thrust coefficient for double and triple draft conditions, it uses a fixed model during dynamic positioning control calculations. The damping coefficient and propeller thrust coefficient remain constant values, preventing continuous adaptive adjustment based on varying water depth-to-draft ratios, making it difficult to adapt to dynamic positioning control in shallow waters.

[0005] Currently, traditional dynamic positioning (DP) systems are typically designed based on deepwater dynamic models. Their mass matrix, damping coefficient, and thruster parameters are fixed values ​​after calibration through onboard ship identification tests. Controller parameters are also uncorrelated with water depth. Direct application in shallow waters can easily lead to technical defects such as control drift and instability caused by increased hull inertia, increased damping, and thrust loss. Existing DP technology fails to consider shallow or even extremely shallow water applications and lacks adaptive adjustment and compensation mechanisms for the hull dynamics model (inertial mass, damping coefficient) and thruster thrust loss. Summary of the Invention

[0006] The present invention aims to solve the problem that existing dynamic positioning technologies do not take into account application scenarios in shallow or even extremely shallow waters. To this end, the present invention provides a method and system for dynamic positioning control of ships in full-depth sea areas, defines a dimensionless parameter: water depth to draft ratio, and provides correction formulas for the hull inertial mass, damping coefficient, and propeller thrust loss related thereto, establishes an adaptive dynamic model of ships in full-depth sea areas, and performs adaptive water depth dynamic positioning control based on real-time water depth measurement. The present invention enables the dynamic positioning system to be compatible with the control requirements of deep and shallow water operating areas, and avoids problems such as control drift, instability divergence, etc. caused by increased hull inertia, increased damping, and thrust loss in shallow waters. In the field of application of dynamic positioning systems, it has important engineering practice value that is significantly different from other methods and is irreplaceable.

[0007] The present invention provides a method for controlling dynamic positioning of a ship in full-depth waters, and the technical solution adopted is as follows: comprising the following steps:

[0008] S1: Real-time measurement of water depth and calculation of water depth to draft ratio based on the ship's draft;

[0009] S2: Update the depth-adaptive hull dynamics model according to the water depth-draft ratio;

[0010] In S2, the change rate of the water depth draft ratio is calculated according to the water depth draft ratio and the currently used water depth draft ratio; when the change rate of the water depth draft ratio exceeds the threshold, the inertial mass matrix and the damping coefficient matrix are calculated, and the water depth adaptive hull dynamics model is updated; otherwise, the inertial mass matrix and the damping coefficient matrix are kept unchanged;

[0011] S3: Based on the updated depth-adaptive hull dynamics model, the optimal control force is calculated using the optimized quadratic index;

[0012] S4: Perform dynamic positioning control based on the real-time optimal control force.

[0013] Furthermore, the threshold is 10%.

[0014] Furthermore, the inertial mass matrix The calculation formula is:

[0015]

[0016] in, is the water depth to draft ratio, is the longitudinal mass of the ship including the additional mass under different water depth conditions, is the transverse mass of the ship including the additional mass under different water depth conditions, is the bow inertia of the ship including the additional mass under different water depth conditions, is the coupled mass of the ship's bow to the transverse direction including the additional mass under different water depth conditions, is the coupled mass of the ship's transverse bow direction including the additional mass under different water depth conditions, is the longitudinal mass of the ship including the additional mass in the infinite water depth area, is the transverse mass of the ship including the additional mass in the infinite water depth area, is the bow inertia of the ship including the additional mass in the infinite water depth area, is the coupled mass of the ship's bow to the transverse direction including the additional mass in the infinite water depth area, is the coupled mass of the ship's transverse direction to the bow including the additional mass in the infinite water depth area, For The relevant first inertial mass matrix correction factor, For The associated second inertial mass matrix correction factor, For The related third inertial mass matrix correction factor, For The associated fourth inertial mass matrix correction factor, For The associated fifth inertial mass matrix correction factor, For The associated sixth inertial mass matrix correction factor, For The related seventh inertial mass matrix correction factor, For The related eighth inertial mass matrix correction factor, For The related ninth inertial mass matrix correction factor, For The associated tenth inertial mass matrix correction factor.

[0017] Furthermore, the damping coefficient matrix The calculation formula is:

[0018]

[0019] in, is the water depth to draft ratio, is the longitudinal damping of the ship under different water depth conditions, is the transverse damping of the ship under different water depth conditions, is the bow damping of the ship under different water depth conditions, is the ship bow-to-transverse coupling damping under different water depth conditions, is the ship's transverse bow coupling damping under different water depth conditions, is the longitudinal damping of the ship in the infinite water depth area, is the transverse damping of the ship in the infinite water depth area, is the bow damping of the ship in the infinite water depth area, is the ship bow-to-transverse coupling damping in infinite water depth area, is the ship's transverse bow coupling damping in the infinite water depth area, is the first damping coefficient matrix correction coefficient, is the second damping coefficient matrix correction coefficient, is the third damping coefficient matrix correction coefficient, is the fourth damping coefficient matrix correction coefficient, is the fifth damping coefficient matrix correction coefficient, is the sixth damping coefficient matrix correction coefficient, is the seventh damping coefficient matrix correction coefficient, is the eighth damping coefficient matrix correction coefficient, is the ninth damping coefficient matrix correction coefficient, is the tenth damping coefficient matrix correction coefficient.

[0020] Furthermore, the depth-adaptive hull dynamics model is

[0021]

[0022] in, for The first derivative of is the ship position and heading state vector in the geodetic coordinate system, is the transformation matrix between the earth coordinate system and the ship coordinate system, is the heading, for The first derivative of is the state vector of the ship velocity and angular velocity in the ship coordinate system, For real-time optimal control, is the inertial mass matrix, is the damping coefficient matrix.

[0023] Furthermore, we optimize the quadratic index for:

[0024]

[0025] in, is the hull position and heading command set by the user, T is the matrix transpose, is the control error penalty matrix, is the energy consumption penalty matrix, and t is the time.

[0026] Furthermore, in S2, when the rate of change of the water depth-draft ratio exceeds a threshold, the thrust performance loss of the propeller is calculated and updated.

[0027] In S4, the thruster thrust performance loss is used as the boundary constraint of the thruster thrust.

[0028] Furthermore, the calculation formula for the thrust performance loss of the propeller is:

[0029]

[0030] in, is the water depth to draft ratio, For the The thrust of each thruster takes into account the thrust loss in shallow water; For the The thrust of a propeller in the infinite water depth area, is the first thrust loss correction coefficient, is the second thrust loss correction factor.

[0031] The present invention also provides a ship dynamic positioning control system for full-depth sea areas, which adopts the following technical solutions: including: a water depth draft ratio calculation module, a parameter update module, a real-time optimal control force calculation module and a thrust distribution module,

[0032] The water depth and draft ratio calculation module is used to measure the water depth in real time and calculate the water depth and draft ratio based on the ship's draft;

[0033] Parameter update module, used to update the depth-adaptive hull dynamics model according to the water depth-draft ratio;

[0034] A real-time optimal control force calculation module is used to calculate the real-time optimal control force based on the updated water depth adaptive hull dynamics model and the optimized quadratic index;

[0035] Thrust distribution module, used for dynamic positioning control based on real-time optimal control force.

[0036] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0037] 1. This invention expresses the ship motion model and propeller thrust model using an exponential decay function. This formulation better captures the characteristics of the out-of-water hull inertial mass, damping coefficient, and propeller thrust loss, which vary dramatically in shallow water (three times the draft or less) and more gradually in deep water (three times the draft or greater). Based on the calibrated model curve, a unified and continuous functional relationship is established between the depth-adaptive hull dynamics model and the key parameter, the water depth-to-draft ratio, effectively avoiding model inaccuracy.

[0038] 2. The present invention can calculate the current inertial mass matrix, damping coefficient matrix and thrust performance loss according to the change of water depth, adaptively construct a hull dynamics model that matches the water depth, and then automatically optimize the controller control parameters and thrust distribution parameters, significantly improving the control accuracy in different waters, especially shallow waters.

[0039] 3. This invention is highly compatible with existing dynamic positioning systems, solving the instability issues often associated with shallow-water dynamic positioning without negatively impacting deep-water dynamic positioning control. It is particularly suitable for dynamically positioned vessels requiring precise positioning control in both deep and shallow waters.

[0040] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 It is a flow chart of the method provided by the present invention.

[0043] Figure 2 This is the control effect-time history diagram of the conventional method.

[0044] Figure 3 This is the control effect-time history diagram of this method.

[0045] Figure 4 This is the control effect-trajectory diagram of the conventional method.

[0046] Figure 5 This is the control effect-trajectory diagram of this method.

[0047] Figure 6 It is a structural block diagram of the system provided by the present invention.

[0048] Reference numerals:

[0049] 1. Water depth and draft ratio calculation module; 2. Parameter update module; 3. Real-time optimal control force calculation module; 4. Thrust distribution module. DETAILED DESCRIPTION

[0050] To make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0051] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0052] The following combination Figures 1 to 6 The present invention is further described in detail, and a method and system for controlling dynamic positioning of a ship in full water depth is described.

[0053] In this embodiment, Figure 1 As shown, a method for controlling dynamic positioning of a ship in full water depth is provided, comprising the following steps:

[0054] S1: Measure the water depth in real time and calculate the water depth to draft ratio based on the ship's draft.

[0055] water depth The ship's draft depth can be obtained by real-time measurement using a water depth sensor. Since it is a known value, the water depth and draft ratio can be calculated. , .

[0056] S2: Update the depth-adaptive hull dynamics model according to the water depth-draft ratio.

[0057] The water depth sensor is generally sampled at a frequency of 10 Hz, and the value of the water depth draft ratio changes frequently. Therefore, a threshold needs to be set to avoid frequent fluctuations in the model and control output.

[0058] This embodiment sets a threshold value, and calculates the change rate of the water depth draft ratio according to the water depth draft ratio. When the change rate of the water depth draft ratio exceeds the threshold value, the water depth adaptive hull dynamics model update will be triggered. Calculate the inertial mass matrix and the damping coefficient matrix.

[0059] In this embodiment, when the rate of change of the water depth draft ratio exceeds a threshold, the thrust performance loss of the propeller needs to be updated. This loss serves as a boundary constraint for calculating the thrust of each propeller in step S4.

[0060] In general, the change rate of the water depth-draft ratio is calculated based on the water depth-draft ratio and the currently used water depth-draft ratio; when the change rate of the water depth-draft ratio exceeds the threshold, the inertial mass matrix, damping coefficient matrix and propeller thrust performance loss are calculated, and the water depth-adaptive hull dynamics model is updated; when the change rate of the water depth-draft ratio does not exceed the threshold, the inertial mass matrix, damping coefficient matrix and propeller thrust performance loss are kept unchanged.

[0061] In this embodiment, the threshold is set to 10%, and the condition for model update can be expressed as:

[0062]

[0063] in, The water depth to draft ratio currently used for the depth-adaptive hull dynamics model.

[0064] Inertial mass matrix Using the exponential decay function shown in formula (1), the calculation formula is:

[0065] (1)

[0066] in, is the water depth to draft ratio, is the longitudinal mass of the ship including the additional mass under different water depth conditions, is the transverse mass of the ship including the additional mass under different water depth conditions, is the bow inertia of the ship including the additional mass under different water depth conditions, is the coupled mass of the ship's bow to the transverse direction including the additional mass under different water depth conditions, is the coupled mass of the ship's transverse bow direction including the additional mass under different water depth conditions, is the longitudinal mass of the ship including the additional mass in the infinite water depth area, is the transverse mass of the ship including the additional mass in the infinite water depth area, is the bow inertia of the ship including the additional mass in the infinite water depth area, is the coupled mass of the ship's bow to the transverse direction including the additional mass in the infinite water depth area, is the coupled mass of the ship's transverse direction to the bow including the additional mass in the infinite water depth area, For The relevant first inertial mass matrix correction factor, For The associated second inertial mass matrix correction factor, For The related third inertial mass matrix correction factor, For The associated fourth inertial mass matrix correction factor, For The associated fifth inertial mass matrix correction factor, For The associated sixth inertial mass matrix correction factor, For The related seventh inertial mass matrix correction factor, For The related eighth inertial mass matrix correction factor, For The related ninth inertial mass matrix correction factor, For The related tenth inertial mass matrix correction factor, e is a natural base.

[0067] 、 、 、 、 、 、 、 、 、 、 、 、 、 、 All of these parameters are calculated after sampling from a real ship identification test. Specifically, at least three test areas with different draft ratios are selected for ship acceleration tests. Based on the test results, the above parameters are calculated using formula (1). In this embodiment, based on the control characteristics of the ship at different water depths, the draft ratios for the real ship identification test are 1.5 times the draft ratio, 2.5 times the draft ratio, and 3.5 times the draft ratio.

[0068] Damping coefficient matrix Using the exponential decay function shown in formula (2), the calculation formula is:

[0069] (2)

[0070] in, is the longitudinal damping of the ship under different water depth conditions, is the transverse damping of the ship under different water depth conditions, is the bow damping of the ship under different water depth conditions, is the ship bow-to-transverse coupling damping under different water depth conditions, is the ship's transverse bow coupling damping under different water depth conditions, is the longitudinal damping of the ship in the infinite water depth area, is the transverse damping of the ship in the infinite water depth area, is the bow damping of the ship in the infinite water depth area, is the ship bow-to-transverse coupling damping in infinite water depth area, is the ship's transverse bow coupling damping in the infinite water depth area, is the first damping coefficient matrix correction coefficient, is the second damping coefficient matrix correction coefficient, is the third damping coefficient matrix correction coefficient, is the fourth damping coefficient matrix correction coefficient, is the fifth damping coefficient matrix correction coefficient, is the sixth damping coefficient matrix correction coefficient, is the seventh damping coefficient matrix correction coefficient, is the eighth damping coefficient matrix correction coefficient, is the ninth damping coefficient matrix correction coefficient, is the tenth damping coefficient matrix correction coefficient.

[0071] 、 、 、 、 、 、 、 、 、 、 、 、 、 、 All of these parameters are calculated after sampling from actual ship identification tests. Specifically, at least three test areas with different draft ratios are selected for ship uniform speed tests. Based on the test results, the above parameters are calculated using Equation (2). In this embodiment, based on the control characteristics of the ship at different water depths, the draft ratios selected are 1.5 times the draft ratio, 2.5 times the draft ratio, and 3.5 times the draft ratio.

[0072] The thrust performance loss of the propeller is calculated using the exponential decay function shown in formula (3):

[0073] (3)

[0074] in, For the The thrust of each thruster takes into account the thrust loss in shallow water; For the The thrust of a propeller in the infinite water depth area, is the first thrust loss correction coefficient, is the second thrust loss correction coefficient. The two correction coefficients are calculated through sampling from the actual ship identification test.

[0075] In this embodiment, only one threshold is set to determine whether to update the inertial mass matrix, damping coefficient matrix, and thrust performance loss simultaneously. Depending on actual usage, three thresholds can also be set to determine whether to update the inertial mass matrix, damping coefficient matrix, and thrust performance loss respectively.

[0076] S3: Based on the updated depth-adaptive hull dynamics model, the real-time optimal control force is calculated using the optimized quadratic index.

[0077] The depth-adaptive hull dynamics model is shown in Equation (4):

[0078] (4)

[0079] in, for The first derivative of is the ship position and heading state vector in the geodetic coordinate system, , N is the north position, E is the east position, is the heading, T is the matrix transpose, is the transformation matrix between the earth coordinate system and the ship coordinate system, , , for The first derivative of is the state vector of the ship velocity and angular velocity in the ship coordinate system, , is the longitudinal velocity of the hull in the hull coordinate system, is the lateral velocity of the ship in the ship coordinate system, is the angular velocity of the ship in the ship coordinate system, For real-time optimal control.

[0080] The depth-adaptive hull dynamics model is transformed into a linear steady-state standard form, as shown in Equation (5):

[0081] (5)

[0082] in, for The first derivative of is the ship motion state vector, , is the system matrix, , is the input matrix, , is the output matrix, , is the identity matrix.

[0083] According to formula (5), set the optimal quadratic index , as shown in formula (6):

[0084] (6)

[0085] Where t is time, The hull position and heading instructions set by the user, , The hull latitude coordinate set by the user, The hull longitude coordinates set by the user, The heading of the ship is set by the user. is the control error penalty matrix, is the energy consumption penalty matrix, and Both are diagonal matrices, and the weights can be adjusted by the user; Characterizes the control error penalty term, Characterizes the energy consumption penalty term of the control process.

[0086] Preferably, in order to ensure the control effect in shallow water area, Designed for There is a negative correlation, Designed for There is a positive correlation; when When the change exceeds the threshold, both are triggered to update.

[0087] Finally, according to formula (7), the optimal quadratic index is calculated. Achieving the minimum real-time optimal control force .

[0088] (7)

[0089] in, is the only positive definite solution to the Riccati algebraic equation.

[0090] S4: Perform dynamic positioning control based on the real-time optimal control force.

[0091] Thrust distribution module As the boundary constraint of the thruster, the optimal control force The calculation is converted into control instructions for each propeller, which drives the actuator to generate thrust and control the ship's motion. The thrust distribution module is an existing technology, and its working process will not be described in detail.

[0092] This method is aimed at dynamic positioning applications in all water depths, especially for dynamically positioned vessels that require precise positioning control in both deep and shallow waters.

[0093] In this embodiment, a small test vessel is used as the test object to verify the effectiveness of the method. The small test vessel has a draft of 30 cm and is equipped with four azimuth thrusters of the same model.

[0094] During the model calibration phase, the motion model parameters and thrust loss parameters were obtained by calibrating the model in different water depths, and the model parameter curve was calculated based on these parameters, as shown in Table 1.

[0095] Table 1

[0096]

[0097] In the control implementation phase, the ambient wind speed is set to 12m / s, the wave is level 4 sea state, the current speed is 2 knots, the wind, wave and current are all 0°, the heading instruction is 330°, and in the water depth of 1.3 times the draft of the ship, the conventional method (inertial mass matrix, damping coefficient matrix and propeller thrust performance loss do not change with the water depth and draft ratio) and the present method are used to carry out the fixed-point positioning comparison test. The results are shown in Table 2 and Table 2. Figures 2 to 5 .

[0098] Table 2

[0099]

[0100] This embodiment also provides a ship dynamic positioning control system for full-depth sea areas, such as Figure 6As shown, the adopted technical solution is as follows: including: a water depth draft ratio calculation module 1, a parameter update module 2, a real-time optimal control force calculation module 3 and a thrust distribution module 4.

[0101] The water depth and draft ratio calculation module 1 is used to measure the water depth in real time and calculate the water depth and draft ratio in combination with the draft of the ship.

[0102] Parameter Update Module 2 is used to update the depth-adaptive hull dynamics model based on the depth-draft ratio. Specifically, the rate of change of the depth-draft ratio is calculated based on the depth-draft ratio and the currently used depth-draft ratio. When the rate of change of the depth-draft ratio exceeds a threshold, the inertial mass matrix, damping coefficient matrix, and propeller thrust performance loss are calculated. The depth-adaptive hull dynamics model is updated based on the inertial mass matrix and damping coefficient matrix. The propeller thrust performance loss is input into the thrust allocation module as a boundary constraint for the propeller thrust. Otherwise, the inertial mass matrix, damping coefficient matrix, and propeller thrust performance loss remain unchanged.

[0103] The real-time optimal control force calculation module 3 is used to calculate the real-time optimal control force based on the updated water depth adaptive hull dynamics model and the optimized quadratic index.

[0104] The thrust distribution module 4 is used to perform dynamic positioning control according to the real-time optimal control force.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A ship dynamic positioning control method for full-depth sea areas, characterized in that: The following steps are involved: S1: Real-time measurement of water depth and calculation of water depth to draft ratio based on the ship's draft; S2: Update the depth-adaptive hull dynamics model according to the water depth-draft ratio; In S2, the change rate of the water depth draft ratio is calculated according to the water depth draft ratio and the currently used water depth draft ratio; When the rate of change of the water depth-draft ratio exceeds a threshold, the inertial mass matrix and the damping coefficient matrix are calculated and the depth-adaptive hull dynamics model is updated; otherwise, the inertial mass matrix and the damping coefficient matrix remain unchanged. Inertial mass matrix The calculation formula is: in, is the water depth to draft ratio, is the longitudinal mass of the ship including the additional mass under different water depth conditions, is the transverse mass of the ship including the additional mass under different water depth conditions, is the bow inertia of the ship including the additional mass under different water depth conditions, is the coupled mass of the ship's bow to the transverse direction including the additional mass under different water depth conditions, is the coupled mass of the ship's transverse bow direction including the additional mass under different water depth conditions, is the longitudinal mass of the ship including the additional mass in the infinite water depth area, is the transverse mass of the ship including the additional mass in the infinite water depth area, is the bow inertia of the ship including the additional mass in the infinite water depth area, is the coupled mass of the ship's bow to the transverse direction including the additional mass in the infinite water depth area, is the coupled mass of the ship's transverse direction to the bow including the additional mass in the infinite water depth area, For The relevant first inertial mass matrix correction factor, For The associated second inertial mass matrix correction factor, For The relevant third inertial mass matrix correction factor, For The associated fourth inertial mass matrix correction factor, For The associated fifth inertial mass matrix correction factor, For The associated sixth inertial mass matrix correction factor, For The related seventh inertial mass matrix correction factor, For The related eighth inertial mass matrix correction factor, For The related ninth inertial mass matrix correction factor, For The associated tenth inertial mass matrix correction factor; S3: Based on the updated depth-adaptive hull dynamics model, the optimal control force is calculated using the optimized quadratic index; S4: Perform dynamic positioning control based on the real-time optimal control force.

2. A method for controlling dynamic positioning of a ship in full water depth according to claim 1, characterized in that: The threshold is 10%.

3. The method for controlling dynamic positioning of a ship in full water depth as claimed in claim 1, characterized in that: Damping coefficient matrix The calculation formula is: in, is the water depth to draft ratio, is the longitudinal damping of the ship under different water depth conditions, is the transverse damping of the ship under different water depth conditions, is the bow damping of the ship under different water depth conditions, is the ship bow-to-transverse coupling damping under different water depth conditions, is the ship's transverse bow coupling damping under different water depth conditions, is the longitudinal damping of the ship in the infinite water depth area, is the transverse damping of the ship in the infinite water depth area, is the bow damping of the ship in the infinite water depth area, is the ship bow-to-transverse coupling damping in infinite water depth area, is the ship's transverse bow coupling damping in the infinite water depth area, is the first damping coefficient matrix correction coefficient, is the second damping coefficient matrix correction coefficient, is the third damping coefficient matrix correction coefficient, is the fourth damping coefficient matrix correction coefficient, is the fifth damping coefficient matrix correction coefficient, is the sixth damping coefficient matrix correction coefficient, is the seventh damping coefficient matrix correction coefficient, is the eighth damping coefficient matrix correction coefficient, is the ninth damping coefficient matrix correction coefficient, is the tenth damping coefficient matrix correction coefficient.

4. A method for controlling dynamic positioning of a ship in full water depth according to any one of claims 1, characterized in that: The depth-adaptive hull dynamics model is in, for The first derivative of is the ship position and heading state vector in the geodetic coordinate system, is the transformation matrix between the earth coordinate system and the ship coordinate system, For the heading, for The first derivative of is the state vector of the ship velocity and angular velocity in the ship coordinate system, For real-time optimal control, is the inertial mass matrix, is the damping coefficient matrix.

5. The method for controlling dynamic positioning of a ship in full water depth as claimed in claim 4, characterized in that: Optimizing quadratic indicators for: in, is the hull position and heading command set by the user, T is the matrix transpose, is the control error penalty matrix, is the energy consumption penalty matrix, and t is the time.

6. The method for controlling dynamic positioning of a ship in full water depth as claimed in claim 1, characterized in that: In S2, when the rate of change of the water depth draft ratio exceeds the threshold, the thrust performance loss of the propeller is calculated and updated. In S4, the thruster thrust performance loss is used as the boundary constraint of the thruster thrust.

7. A method for controlling dynamic positioning of a ship in full water depth as claimed in claim 6, characterized in that: The calculation formula for the thrust performance loss of the propeller is: in, is the water depth to draft ratio, For the The thrust of each thruster takes into account the thrust loss in shallow water; For the The thrust of a propeller in the infinite water depth area, is the first thrust loss correction coefficient, is the second thrust loss correction factor.

8. A ship dynamic positioning control system for full-depth sea areas, characterized by: The method is used to execute a full-depth ship dynamic positioning control method according to any one of claims 1 to 7, comprising: a water depth draft ratio calculation module, a parameter update module, a real-time optimal control force calculation module, and a thrust distribution module. The water depth and draft ratio calculation module is used to measure the water depth in real time and calculate the water depth and draft ratio based on the ship's draft; Parameter update module, used to update the depth-adaptive hull dynamics model according to the water depth-draft ratio; A real-time optimal control force calculation module is used to calculate the real-time optimal control force based on the updated water depth adaptive hull dynamics model and the optimized quadratic index; Thrust distribution module, used for dynamic positioning control based on real-time optimal control force.

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