Ship dynamic positioning control method and system for full-water-depth sea area

Abstract

The invention relates to the technical field of ship motion control, and particularly discloses a ship dynamic positioning control method and system for a full-water-depth sea area, and the method comprises the steps: S1, measuring the water depth in real time, and calculating the water depth-to-draft ratio through combining with the ship draft; s2, according to the water depth-to-draft ratio, a water depth self-adaptive ship body dynamic model is updated; s3, calculating real-time optimal control force by utilizing an optimal quadratic index according to the updated water depth self-adaptive ship body dynamic model; and S4, performing dynamic positioning control according to the real-time optimal control force. The dynamic positioning system can be compatible with control requirements of deep water and shallow water operation areas, and the problems of control drift, instability divergence and the like caused by inertia increase, damping increase and thrust loss of a ship body in a shallow water area are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of ship motion control, and particularly relates to a ship dynamic positioning control method and system for the full water depth sea area. Background Technique

[0002] A ship dynamic positioning system is a closed-loop control system that relies on its own propulsion device to automatically resist environmental interferences such as wind, waves, and currents at sea and achieve precise control of the ship's position and heading. Traditional dynamic positioning (DP) systems are usually designed based on deep water dynamics models. After the mass matrix, damping coefficient, and thruster thrust parameters are calibrated through full-scale ship commissioning, they are all fixed values and can maintain good control performance in deep water areas (where the water depth to draft ratio is greater than 3).

[0003] When the ship enters the shallow water area, the following situations will occur: 1. The distance between the seabed and the ship bottom is too small, which hinders the fluid flow around the hull, resulting in a significant increase in the added mass, which can reach 2-3 times that in the deep water area, and the inertial characteristics of the hull change significantly. 2. Due to the limited wave propagation, energy reflection, and breaking, the dissipation increases and the wave-making damping increases; at the same time, the flow velocity between the seabed and the ship bottom increases, and the friction effect is enhanced, and the viscous damping also increases; thus, the ship's fluid damping coefficient shows a non-linear increase, and the thrust required to correct the control error needs to be improved. 3. The thrust loss of the thruster in the shallow water area can reach 40%. Without corresponding compensation, insufficient thrust often occurs. Many factors often lead to the phenomenon of positioning drift or even instability in traditional dynamic positioning control in the shallow water area.

[0004] The Chinese invention patent with the application publication number CN117215318A discloses a dynamic positioning ship control method for water depth changes, including: collecting the damping coefficient and thruster thrust coefficient of the ship under different draft conditions, and constructing the thruster model and low-frequency motion model of the ship. Although this patent calculates the damping coefficient and thruster thrust coefficient respectively under the double draft condition and the triple draft condition, when performing dynamic positioning control calculations, a fixed model is applied, and its damping coefficient and thruster thrust coefficient are still fixed values and cannot be continuously and adaptively adjusted according to the different water depth to draft ratios, making it difficult to adapt to the dynamic positioning control in the shallow water area.

[0005] Currently, traditional dynamic positioning (DP) systems are usually designed based on deep water dynamics models. After the mass matrix, damping coefficient, and thruster thrust parameters are calibrated through full-scale ship identification tests, they are all fixed values, and the controller parameters are also not related to the water depth. When directly applied to the shallow water area, technical defects such as increased hull inertia, increased damping, control drift, and instability divergence caused by thrust loss are likely to occur. Existing dynamic positioning technologies do not consider the application scenarios in shallow water or even extremely shallow waters, and lack an adaptive adjustment and compensation mechanism 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 the existing dynamic positioning technology does not consider the application scenarios in shallow water or even extremely shallow water areas. For this purpose, the present invention provides a ship dynamic positioning control method and system for the entire water depth sea area, defines a dimensionless parameter: the water depth-draft ratio, and gives the correction formulas for the hull inertial mass, damping coefficient, and thruster thrust loss related to it, establishes an adaptive dynamics model of the ship for the entire water depth sea area, and performs dynamic positioning control with adaptive water depth based on real-time water depth measurement. The present invention can enable the dynamic positioning system to be compatible with the control requirements of deep water and shallow water operation areas, and avoid problems such as control drift and instability divergence caused by the increase in hull inertia, damping, and thrust loss in shallow water areas. In the application field of the dynamic positioning system, it has obvious and irreplaceable important engineering practice value different from other methods.

[0007] The present invention provides a ship dynamic positioning control method for the entire water depth sea area, and the technical solutions adopted are as follows: including the following steps: S1: Measure the water depth in real time, and calculate the water depth-draft ratio in combination with the ship draft depth; S2: Update the hull dynamics model with adaptive water depth according to the water depth-draft ratio; In S2, according to the water depth-draft ratio and the currently used water depth-draft ratio, calculate the change rate of the water depth-draft ratio; when the change rate of the water depth-draft ratio exceeds the threshold, calculate the inertial mass matrix and the damping coefficient matrix, and update the hull dynamics model with adaptive water depth; otherwise, keep the inertial mass matrix and the damping coefficient matrix unchanged; S3: According to the updated hull dynamics model with adaptive water depth, use the optimal quadratic form index to calculate the real-time optimal control force; S4: Perform dynamic positioning control according to the real-time optimal control force.

[0008] Further, the threshold is 10%.

[0009] Further, the inertial mass matrix The calculation formula is: Where is the water depth-draft ratio, is the longitudinal mass of the ship including added mass under different water depth conditions, is the transverse mass of the ship including added mass under different water depth conditions, is the yaw inertia of the ship including added mass under different water depth conditions, is the coupling mass of the ship's heading to the transverse including added mass under different water depth conditions, is the coupling mass of the ship's transverse to the heading including added mass under different water depth conditions, is the longitudinal mass of the ship including added mass in the infinite water depth area, is the transverse mass of the ship including added mass in the infinite water depth area, is the yaw inertia of the ship including added mass in the infinite water depth area, is the coupling mass of the ship's heading to transverse in the infinite water depth area including added mass, is the coupling mass of the ship's transverse to heading in the infinite water depth area including added mass, is related to the first correction coefficient of the inertia mass matrix, is related to the second correction coefficient of the inertia mass matrix, is related to the third correction coefficient of the inertia mass matrix, is related to the fourth correction coefficient of the inertia mass matrix, is related to the fifth correction coefficient of the inertia mass matrix, is related to the sixth correction coefficient of the inertia mass matrix, is related to the seventh correction coefficient of the inertia mass matrix, is related to the eighth correction coefficient of the inertia mass matrix, is related to the ninth correction coefficient of the inertia mass matrix, is related to the tenth correction coefficient of the inertia mass matrix.

[0010] Furthermore, the damping coefficient matrix is calculated by the formula: where, is the water depth 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 yaw damping of the ship under different water depth conditions, is the coupling damping of the ship's heading to transverse under different water depth conditions, is the coupling damping of the ship's transverse to heading 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 yaw damping of the ship in the infinite water depth area, is the coupling damping of the ship's heading to the lateral direction in the infinite water depth area, is the coupling damping of the ship's lateral direction to the heading in the infinite water depth area, is the correction coefficient of the first damping coefficient matrix, is the correction coefficient of the second damping coefficient matrix, is the correction coefficient of the third damping coefficient matrix, is the correction coefficient of the fourth damping coefficient matrix, is the correction coefficient of the fifth damping coefficient matrix, is the correction coefficient of the sixth damping coefficient matrix, is the correction coefficient of the seventh damping coefficient matrix, is the correction coefficient of the eighth damping coefficient matrix, is the correction coefficient of the ninth damping coefficient matrix, is the correction coefficient of the tenth damping coefficient matrix.

[0011] Furthermore, the hull dynamics model with water depth adaptability is wherein, is the first derivative of, is the ship position and heading state vector in the earth coordinate system, is the transformation matrix between the earth coordinate system and the hull coordinate system, is the heading, is the first derivative of, is the hull velocity and angular velocity state vector in the hull coordinate system, is the real-time optimal control force, is the inertial mass matrix, is the damping coefficient matrix.

[0012] Furthermore, the optimized quadratic form index is: wherein, 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.

[0013] Furthermore, in S2, when the change rate of the water depth to draft ratio exceeds the threshold, calculate and update the thruster thrust performance loss, In S4, the thruster thrust performance loss is used as the boundary constraint of the thruster thrust.

[0014] Furthermore, the calculation formula of the thruster thrust performance loss is: Among them, is the water depth draft ratio, is the th thruster's thrust considering the shallow water thrust loss; is the th thruster's thrust in the infinite water depth area, is the first thrust loss correction coefficient, is the second thrust loss correction coefficient.

[0015] The present invention also provides a ship dynamic positioning control system for the whole water depth sea area, and the adopted technical solution is as follows: 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, The water depth draft ratio calculation module is used to measure the water depth in real time and calculate the water depth draft ratio in combination with the ship's draft depth; The parameter update module is used to update the hull dynamics model adapted to the water depth according to the water depth draft ratio; The real-time optimal control force calculation module is used to calculate the real-time optimal control force by using the optimized quadratic form index according to the updated hull dynamics model adapted to the water depth; The thrust distribution module is used to perform dynamic positioning control according to the real-time optimal control force.

[0016] One or more of the above technical solutions in the embodiments of the present invention have at least one of the following technical effects: 1. The present invention expresses the ship motion model and the thruster thrust model in the form of an exponential decay function. This form can better fit the characteristics that the hull inertia mass, damping coefficient, and thruster thrust loss of the watercraft change violently in the shallow water area (shallower than 3 times the draft) and change gently in the deep water area (deeper than 3 times the draft). Based on the calibrated model curve, a unified and continuous functional relationship between the hull dynamics model adapted to the water depth and the key parameter of the water depth draft ratio is established, effectively avoiding the problem of model inaccuracy.

[0017] 2. The present invention can calculate the current inertia mass matrix, damping coefficient matrix and thrust performance loss according to the water depth change, adaptively construct a hull dynamics model matching the water depth, and then automatically optimize the controller control parameters and thrust distribution parameters, significantly improving the control accuracy in different water areas, especially in the shallow water area.

[0018] 3. The present invention has good compatibility with the original dynamic positioning system. Without negative impact on the dynamic positioning control in the deep water area, it solves the instability problem frequently occurring in the shallow water dynamic positioning. It is especially suitable for dynamic positioning ships with precise positioning control requirements in both deep water areas and shallow water areas.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned by practice of the present invention. Brief Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 is a flowchart of the method provided by the present invention.

[0022] Figure 2 is a control effect-time history diagram of a conventional method.

[0023] Figure 3 is a control effect-time history diagram of this method.

[0024] Figure 4 is a control effect-trajectory diagram of a conventional method.

[0025] Figure 5 is a control effect-trajectory diagram of this method.

[0026] Figure 6 is a structural block diagram of the system provided by the present invention.

[0027] Reference Signs: 1. Water Depth-Draft Ratio Calculation Module; 2. Parameter Update Module; 3. Real-Time Optimal Control Force Calculation Module; 4. Thrust Allocation Module. Detailed Embodiments

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0029] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic expressions of the above terms do 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, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0030] The following will further elaborate on the present invention in conjunction with Figures 1 to 6 to describe a ship dynamic positioning control method and system for the full water depth sea area of the present invention: In this embodiment, as Figure 1 shown, a ship dynamic positioning control method for the full water depth sea area is provided, including the following steps: S1: Measure the water depth in real time and calculate the water depth draft ratio in combination with the ship draft depth.

[0031] The water depth can be obtained by real-time measurement through a water depth sensor. The ship draft depth is a known value, so the water depth draft ratio can be calculated , .

[0032] S2: Update the hull dynamics model with water depth adaptability according to the water depth draft ratio.

[0033] The water depth sensor generally samples at a frequency of 10Hz, and the value of the water depth draft ratio changes very frequently. Therefore, a threshold needs to be set to avoid frequent fluctuations in the model and control output.

[0034] In this embodiment, a threshold is set. The change rate of the water depth draft ratio is calculated according to the water depth draft ratio. When the change rate of the water depth draft ratio exceeds the threshold, the update of the hull dynamics model with water depth adaptability will be triggered, and the inertial mass matrix and damping coefficient matrix need to be calculated according to the at this time.

[0035] In this embodiment, when the change rate of the water depth draft ratio exceeds the threshold, the thruster thrust performance loss also needs to be updated. This loss is used as the boundary constraint for calculating the thrust of each thruster in step S4.

[0036] Generally speaking, according to the water depth draft ratio and the currently used water depth draft ratio, the change rate of the water depth draft ratio is calculated; when the change rate of the water depth draft ratio exceeds the threshold, the inertia mass matrix, damping coefficient matrix, and thruster thrust performance loss are calculated, and the hull dynamics model with water depth adaptation is updated; when the change rate of the water depth draft ratio does not exceed the threshold, the inertia mass matrix, damping coefficient matrix, and thruster thrust performance loss remain unchanged.

[0037] In this embodiment, the threshold is set to 10%, and the condition for model update can be expressed as: Wherein, is the water depth draft ratio currently used by the hull dynamics model with water depth adaptation.

[0038] Inertia mass matrix Adopts the form of the exponential decay function shown in Equation (1), and the calculation formula is: (1) Wherein, is the water depth draft ratio, is the longitudinal mass of the ship including added mass under different water depth conditions, is the transverse mass of the ship including added mass under different water depth conditions, is the yaw inertia of the ship including added mass under different water depth conditions, is the coupling mass of the ship's heading to the transverse direction including added mass under different water depth conditions, is the coupling mass of the ship's transverse to the heading direction including added mass under different water depth conditions, is the longitudinal mass of the ship including added mass in the infinite water depth area, is the transverse mass of the ship including added mass in the infinite water depth area, is the yaw inertia of the ship including added mass in the infinite water depth area, is the coupling mass of the ship's heading to the transverse direction including added mass in the infinite water depth area, is the coupling mass of the ship's transverse to the heading direction including added mass in the infinite water depth area, is related to the first inertia mass matrix correction coefficient, is related to the second inertia mass matrix correction coefficient, is related to the third inertia mass matrix correction coefficient, is related to the fourth inertia mass matrix correction coefficient, is related to The relevant fifth inertia mass matrix correction coefficient, is the relevant sixth inertia mass matrix correction coefficient, is the relevant seventh inertia mass matrix correction coefficient, is the relevant eighth inertia mass matrix correction coefficient, is the relevant ninth inertia mass matrix correction coefficient, is the relevant tenth inertia mass matrix correction coefficient, where e is the natural base.

[0039] , , , , , , , , , , , , , , are all obtained by calculation after sampling through full-scale ship identification tests. Specifically, at least 3 test areas with different draft ratios are selected for ship acceleration tests, and according to the test results, the above parameters are calculated using Equation (1). In this embodiment, according to the control characteristics of the ship at different water depths, the draft ratios for the full-scale ship identification tests are selected as 1.5 times the draft ratio, 2.5 times the draft ratio, and 3.5 times the draft ratio.

[0040] The damping coefficient matrix adopts the exponential decay function form shown in Equation (2), and the calculation formula is: (2) where is the longitudinal damping of the ship under different water depth conditions, is the lateral damping of the ship under different water depth conditions, is the yaw damping of the ship under different water depth conditions, is the longitudinal-to-lateral coupling damping of the ship's heading under different water depth conditions, is the lateral-to-longitudinal coupling damping of the ship's heading under different water depth conditions, is the longitudinal damping of the ship in the infinite water depth region, is the lateral damping of the ship in the infinite water depth region, is the yaw damping of the ship in the infinite water depth region, is the longitudinal-to-lateral coupling damping of the ship's heading in the infinite water depth region, is the lateral-to-heading coupling damping of the ship in the infinite water depth area, is the correction coefficient of the first damping coefficient matrix, is the correction coefficient of the second damping coefficient matrix, is the correction coefficient of the third damping coefficient matrix, is the correction coefficient of the fourth damping coefficient matrix, is the correction coefficient of the fifth damping coefficient matrix, is the correction coefficient of the sixth damping coefficient matrix, is the correction coefficient of the seventh damping coefficient matrix, is the correction coefficient of the eighth damping coefficient matrix, is the correction coefficient of the ninth damping coefficient matrix, is the correction coefficient of the tenth damping coefficient matrix.

[0041] 、 、 、 、 、 、 、 、 、 、 、 、 、 、 are all obtained by calculation after sampling through the full-scale ship identification test. Specifically, at least 3 test areas with different draft ratios are selected for the uniform speed test of the ship. According to the test results, the above parameters are calculated using Equation (2). In this embodiment, according to the control characteristics of the ship at different water depths, the draft ratios are selected as 1.5 times the draft, 2.5 times the draft, and 3.5 times the draft.

[0042] The loss of the thruster thrust performance adopts the form of the exponential decay function shown in Equation (3), and the calculation formula is: (3) where, is the thrust of the th thruster considering the shallow water thrust loss; is the thrust of the th thruster in the infinite water depth area, is the first thrust loss correction coefficient, is the second thrust loss correction coefficient, and the two correction coefficients are obtained by calculation after sampling through the full-scale ship identification test.

[0043] In this embodiment, only one threshold is set to determine whether to update the inertia mass matrix, damping coefficient matrix, and thruster thrust performance loss simultaneously. According to the actual usage, three thresholds can also be set to determine whether to update the inertia mass matrix, damping coefficient matrix, and thruster thrust performance loss respectively.

[0044] S3: According to the updated hull dynamics model adapted to water depth, use the optimal quadratic index to calculate the real-time optimal control force.

[0045] The hull dynamics model adapted to water depth is shown in Equation (4): (4) where is the first derivative of , is the ship position and heading state vector in the earth coordinate system, , N is the northward position, E is the eastward position, is the heading, T is the matrix transpose, is the transformation matrix between the earth coordinate system and the hull coordinate system, , , is 's first derivative, is the hull velocity and angular velocity state vector in the hull coordinate system, , is the longitudinal velocity of the hull in the hull coordinate system, is the lateral velocity of the hull in the hull coordinate system, is the angular velocity of the hull in the hull coordinate system, is the real-time optimal control force.

[0046] Transform the hull dynamics model adapted to water depth into the linear time-invariant state space standard form, as shown in Equation (5): (5) where is 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.

[0047] According to Equation (5), set the optimal quadratic index , as shown in Equation (6): (6) where \(t\) is time, is the hull position and heading command set by the user, , is the hull latitude coordinate set by the user, is the hull longitude coordinate set by the user, is the hull heading set by the user, is the control error penalty matrix, is the energy consumption penalty matrix, and both are diagonal matrices, and the weight values can be set and adjusted by the user; represents the control error penalty term, represents the energy consumption penalty term in the control process.

[0048] Preferably, to ensure the control effect in the shallow water area, is designed to be negatively correlated with , is designed to be positively correlated with ; when changes exceed the threshold, both are triggered to be updated.

[0049] Finally, according to Equation (7), the real-time optimal control force that minimizes the optimized quadratic form index is calculated. .

[0050] (7) where is the unique positive definite solution of the Riccati algebraic equation.

[0051] S4: Perform dynamic positioning control according to the real-time optimal control force.

[0052] The thrust allocation module takes as the boundary constraint of the thruster thrust, resolves the optimal control force into the control commands of each thruster, drives the actuator to generate thrust, and controls the motion attitude of the ship. The thrust allocation module is a prior art, and its working process will not be elaborated.

[0053] This method is for the dynamic positioning application in the whole water depth sea area, especially for the dynamic positioning ship with precise positioning control requirements in both deep water area and shallow water area.

[0054] This embodiment takes a small test ship as the test object to verify the effectiveness of this method. The draft of the small test ship is 30 cm, and it is equipped with 4 full-rotation thrusters of the same model.

[0055] In the model calibration stage, the motion model parameters and thrust loss parameters are calibrated in different water depth regions, and the model parameter curves are calculated therefrom. As shown in Table 1.

[0056] Table 1 In the control implementation stage, the environmental wind speed is set to 12 m / s, the wave condition is sea state 4, the flow velocity is 2 knots, the directions of wind, wave and current are all 0°, the heading command is 330°, and in the water depth area that is 1.3 times the draft of the ship, fixed-point positioning comparison tests are carried out by the conventional method (the inertial mass matrix, damping coefficient matrix and propeller thrust performance loss do not change with the water depth to draft ratio) and this method respectively. The results are shown in Table 2, and Figures 2 to 5 。

[0057] Table 2 This embodiment also provides a ship dynamic positioning control system for the full water depth sea area, as Figure 6 shown, the technical solution adopted is as follows: including: a water depth to 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.

[0058] The water depth to draft ratio calculation module 1 is used to measure the water depth in real time and calculate the water depth to draft ratio in combination with the ship draft depth.

[0059] The parameter update module 2 is used to update the hull dynamics model adapted to the water depth according to the water depth to draft ratio. Specifically, according to the water depth to draft ratio and the currently used water depth to draft ratio, calculate the change rate of the water depth to draft ratio; when the change rate of the water depth to draft ratio exceeds the threshold, calculate the inertial mass matrix, damping coefficient matrix and propeller thrust performance loss, and update the hull dynamics model adapted to the water depth according to the inertial mass matrix and damping coefficient matrix. The propeller thrust performance loss is input into the thrust distribution module as the boundary constraint of the propeller thrust; otherwise, keep the inertial mass matrix, damping coefficient matrix and propeller thrust performance loss unchanged.

[0060] The real-time optimal control force calculation module 3 is used to calculate the real-time optimal control force by using the optimized quadratic index according to the updated hull dynamics model adapted to the water depth.

[0061] The thrust distribution module 4 is used to perform dynamic positioning control according to the real-time optimal control force.

[0062] 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate 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 the whole water depth sea area, characterized in that Including the following steps: S1: Measure the water depth in real time and calculate the water depth draft ratio in combination with the ship's draft; S2: Update the hull dynamic model with water depth adaptation according to the water depth draft ratio; In S2, calculate the change rate of the water depth draft ratio 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, calculate the inertia mass matrix and damping coefficient matrix, and update the hull dynamic model with water depth adaptation; otherwise, keep the inertia mass matrix and damping coefficient matrix unchanged; S3: Calculate the real-time optimal control force using the optimal quadratic index according to the updated hull dynamic model with water depth adaptation; S4: Perform dynamic positioning control according to the real-time optimal control force.

2. The ship dynamic positioning control method for the full water depth sea area according to claim 1, wherein The threshold is 10%.

3. A ship dynamic positioning control method for the full water depth sea area according to claim 1, characterized in that, Inertial mass matrix The calculation formula is as follows: wherein, is the water depth draft ratio, is the longitudinal mass of the ship including added mass under different water depth conditions, is the transverse mass of the ship including added mass under different water depth conditions, is the yaw inertia of the ship including added mass under different water depth conditions, is the coupling mass of the ship's heading to the transverse including added mass under different water depth conditions, is the coupling mass of the ship's transverse to the heading including added mass under different water depth conditions, is the longitudinal mass of the ship including added mass in the infinite water depth region, is the transverse mass of the ship including added mass in the infinite water depth region, is the yaw inertia of the ship including added mass in the infinite water depth region, is the coupling mass of the ship's heading to the transverse including added mass in the infinite water depth region, is the coupling mass of the ship's transverse to the heading including added mass in the infinite water depth region, is the first inertia mass matrix correction coefficient related to is the second inertia mass matrix correction coefficient related to is the third inertia mass matrix correction coefficient related to is the fourth inertia mass matrix correction coefficient related to is the fifth inertia mass matrix correction coefficient related to is the sixth inertia mass matrix correction coefficient related to is the seventh inertia mass matrix correction coefficient related to is the eighth inertia mass matrix correction coefficient related to is the ninth inertia mass matrix correction coefficient related to is the tenth inertia mass matrix correction coefficient related to is the tenth inertia mass matrix correction coefficient related to is the tenth inertia mass matrix correction coefficient related to is the tenth inertia mass matrix correction coefficient related to is the tenth inertia mass matrix correction coefficient related to is the tenth inertia mass matrix correction coefficient related to is the tenth inertia mass matrix correction coefficient related to is the tenth inertia mass matrix correction coefficient related to is the tenth inertia mass matrix correction coefficient related to is the tenth inertia mass matrix correction coefficient related to is the tenth inertia mass matrix correction coefficient related to 4. A ship dynamic positioning control method for the full water depth sea area according to claim 1, characterized in that Damping coefficient matrix The calculation formula is as follows: wherein, is the water depth draft ratio, is the longitudinal damping of the ship under different water depth conditions, is the lateral damping of the ship under different water depth conditions, is the yaw damping of the ship under different water depth conditions, is the coupling damping of the ship's heading to lateral under different water depth conditions, is the coupling damping of the ship's lateral to heading under different water depth conditions, is the longitudinal damping of the ship in the infinite water depth region, is the lateral damping of the ship in the infinite water depth region, is the yaw damping of the ship in the infinite water depth region, is the coupling damping of the ship's heading to lateral in the infinite water depth region, is the coupling damping of the ship's lateral to heading in the infinite water depth region, is the correction coefficient of the first damping coefficient matrix, is the correction coefficient of the second damping coefficient matrix, is the correction coefficient of the third damping coefficient matrix, is the correction coefficient of the fourth damping coefficient matrix, is the correction coefficient of the fifth damping coefficient matrix, is the correction coefficient of the sixth damping coefficient matrix, is the correction coefficient of the seventh damping coefficient matrix, is the correction coefficient of the eighth damping coefficient matrix, is the correction coefficient of the ninth damping coefficient matrix, is the correction coefficient of the tenth damping coefficient matrix.

5. A ship dynamic positioning control method for the whole water depth sea area according to any one of claims 1, characterized in that The hull dynamic model with water depth adaptation is Among them, is the first derivative of, the ship position and heading state vector in the geodetic coordinate system, the transformation matrix between the geodetic coordinate system and the ship body coordinate system, is the heading, is the first derivative of, the ship body velocity and angular velocity state vector in the ship body coordinate system, the real-time optimal control force, the inertial mass matrix, the damping coefficient matrix.

6. The method for controlling the dynamic positioning of a ship for the full water depth sea area according to claim 5, characterized in that, Optimal quadratic form index is as follows: Among them, is the hull position and heading command set for the user, T is the matrix transpose, is the control error penalty matrix, is the energy consumption penalty matrix, and t is the time.

7. A ship dynamic positioning control method for the full water depth sea area according to claim 1, characterized in that In S2, when the change rate of the water depth draft ratio exceeds the threshold, calculate and update the thruster thrust performance loss, In S4, the thruster thrust performance loss is used as the boundary constraint of the thruster thrust.

8. A ship dynamic positioning control method for the full water depth sea area according to claim 7, characterized in that The calculation formula of the thruster thrust performance loss is: in, is the water depth to water 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.

9. A ship dynamic positioning control system for the full water depth sea area, characterized in that For implementing a ship dynamic positioning control method for the full water depth sea area as described in any one of claims 1 to 8, 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, The water depth draft ratio calculation module is used to measure the water depth in real time and calculate the water depth draft ratio in combination with the ship's draft; The parameter update module is used to update the hull dynamic model with water depth adaptation according to the water depth draft ratio; The real-time optimal control force calculation module is used to calculate the real-time optimal control force using the optimal quadratic index according to the updated hull dynamic model with water depth adaptation; The thrust distribution module is used to perform dynamic positioning control according to the real-time optimal control force.

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