A method for calculating the load on moored ships

Abstract

The invention relates to the technical field of moored ships, and in particular to a method for calculating the load of a moored ship. The method comprises: calculating the wind load, the water flow load and the wave load received by a target ship at the last moment according to a wind load calculation formula, a water flow load calculation formula and a wave load estimation formula; measuring the mooring force at the last moment; obtaining the estimated ship force at the last moment according to the wind load, the water flow load, the wave load and the mooring force at the last moment; calculating the ship force at the last moment; judging whether the difference between the estimated ship force at the last moment and the ship force at the last moment is less than or equal to a preset error value; if not, correcting the wave load estimation formula and re-estimating the wave load; if yes, calculating the estimated ship force at the current moment; the invention proposes an accurate moored ship load calculation method, which is helpful to establish a safer and more effective ship mooring system and improve the safety and reliability of the overall operation.

Description

Technical Field

[0001] The present invention relates to the technical field of moored ships, and in particular to a method for calculating the load of a moored ship. Background Art

[0002] The main purpose of ship mooring is to limit the movement of the ship to ensure the safety and smooth progress of the operation. However, in a complex marine environment, one of the challenges faced by ship mooring is how to meet the needs of the operation while avoiding excessive stress on the cables and fenders, which may cause cable breakage or damage to the dock. Traditional mooring systems rely on the restraining force and a certain retractable range provided by the cables, but the sources of external forces that the cables have to resist are complex and diverse, such as wind, waves, and currents. Therefore, when the actual stress conditions of the ship are unknown, the effectiveness and safety of the mooring cables are greatly reduced.

[0003] In dock areas with strong winds, waves and currents, conventional planar layouts usually include bow cables and stern cables, with the addition of transverse cables and reverse cables to improve the load-bearing efficiency of the cables. However, with the increase in the frequency of ship berthing and changes in environmental conditions, the effectiveness of these traditional layouts has been challenged. For these docks that often face extreme conditions, additional mooring equipment may be required to cope with more complex external forces.

[0004] In order to effectively withstand various environmental loads, the best way is to adjust the direction of the cable to the same direction as the external force. However, since the force conditions of the ship are difficult to measure in real time and are complex and changeable, this ideal adjustment method is difficult to achieve in actual operation, lacking sufficient flexibility to adapt to external forces in different directions and mooring points at the dock. Generally, the mooring system should be able to cope with external forces applied from any direction. The most effective strategy is to decompose these external forces into longitudinal and transverse components and calculate how to best withstand these forces. Specifically, some cables should be set longitudinally (such as reverse cables) while others should be set transversely (such as transverse cables) to optimize the force distribution. However, the location and layout of the actual equipment and ships on the dock make this ideal force distribution difficult to achieve. Because the actual force of the ship is difficult to measure directly and difficult to obtain accurately through theoretical calculations. In particular, the estimation of wave loads usually requires long-term data accumulation and statistical analysis of wave height, wave period, and wave direction to obtain reliable results.

[0005] Therefore, there is an urgent need for a calculation method for moored ship loads that can quickly and accurately calculate the forces on moored ships, which will help to establish a safer and more effective ship mooring system and improve the safety and reliability of the overall operation. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a method for calculating the load of a moored ship, which can quickly and accurately calculate the force on the moored ship, help to establish a safer and more effective ship mooring system, and improve the safety and reliability of the overall operation.

[0007] The present invention provides a method for calculating the load of a moored ship, comprising the following steps:

[0008] S1. Obtain historical hydrological conditions through the hydrological monitoring system, and calculate the wind load, water flow load and wave load on the target ship at the last moment according to the historical hydrological conditions, wind load calculation formula, water flow load calculation formula and wave load estimation formula;

[0009] S2, measuring the mooring force at the last moment through the cable force detection system;

[0010] S3. Obtain the estimated ship force at the last moment according to the wind load, water flow load, wave load and mooring force at the last moment;

[0011] S4. Obtaining the position of the ship through a ship motion monitoring system;

[0012] S5. Calculate the acceleration of the ship at the last moment according to the position of the ship;

[0013] S6. Calculate the force on the ship at the last moment according to the acceleration of the ship at the last moment;

[0014] S7, determine whether the difference between the estimated ship force at the previous moment and the ship force at the previous moment is less than or equal to the preset error value; if not, correct the wave load estimation formula and return to S1 to re-estimate the wave load; if so, calculate the estimated ship force at the current moment according to the current wind load calculation formula, water flow load calculation formula, wave load estimation formula and mooring force as the ship load at the current moment.

[0015] Furthermore, in S1, the historical hydrological conditions are obtained through the hydrological monitoring system, and the wind load on the target ship at the last moment is calculated according to the historical hydrological conditions and the wind load calculation formula. The calculation formula is as follows:

[0016] ;

[0017] ;

[0018] Among them, F xw represents the lateral component of wind load, F yw represents the longitudinal component of wind load, A xw Indicates the lateral windward area above the water surface of the hull, A yw It represents the longitudinal windward area above the water surface of the hull, v xrepresents the lateral component of wind speed, v y represents the longitudinal component of wind speed, represents the wind pressure unevenness reduction coefficient, Indicates the correction factor for wind pressure height change.

[0019] Furthermore, in S1, the historical hydrological conditions are obtained through the hydrological monitoring system, and the water flow load received by the target ship at the last moment is calculated according to the historical hydrological conditions and the water flow load calculation formula. The calculation formula is as follows:

[0020] ;

[0021] ;

[0022] Among them, F TC represents the lateral component of the flow load, F LC represents the longitudinal component of the water flow load, C TC represents the lateral component coefficient of water flow force, ρ represents the density of water, V c Indicates the average flow velocity within the ship's draft depth, L BP represents the length between vertical lines of the ship, D' represents the average draft corresponding to the loading degree of the ship, θ c Indicates the angle between the water flow direction and the longitudinal axis of the ship, F LCP represents the longitudinal force component caused by form drag, F LCf Represents the longitudinal component of force caused by frictional resistance.

[0023] Furthermore, in S1, the historical hydrological conditions are obtained through the hydrological monitoring system, and the wave load on the target ship at the last moment is calculated according to the historical hydrological conditions and the wave load estimation formula, which specifically includes:

[0024] The estimated lateral force of the wave load on the target ship at the last moment is estimated by the following formula:

[0025] ;

[0026] Among them, F x represents the estimated lateral force, x represents the comprehensive coefficient of lateral wave force, H represents the incident wave height, θ represents the wave incident angle, L represents the length between the ship columns, D represents the ship draft, and a x represents the lateral magnification factor, γ represents the seawater density, and g represents the gravitational acceleration;

[0027] The estimation formula of the estimated longitudinal force of the wave load on the target ship at the last moment is as follows:

[0028] ;

[0029] Among them, F yrepresents the estimated longitudinal force, y represents the comprehensive coefficient of longitudinal wave force, B represents the ship width, a y Represents the longitudinal magnification factor.

[0030] Furthermore, in S3, based on the wind load, water flow load, wave load and mooring force at the previous moment, the estimated ship forces at the previous moment include:

[0031] The estimated lateral force F of the ship at the last moment is obtained by summing the lateral component of the wind load, the lateral component of the water flow load, the estimated lateral force of the wave load and the lateral component of the mooring force at the last moment. x n-1 ';

[0032] The estimated longitudinal force F of the ship at the last moment is obtained by summing the longitudinal component of the wind load, the longitudinal component of the water flow load, the estimated longitudinal force of the wave load and the longitudinal component of the mooring force at the last moment. y n-1 '.

[0033] Furthermore, in S4, obtaining the position of the ship through the ship motion monitoring system includes:

[0034] The point cloud data of the target ship is measured by a 3D laser instrument, and the lateral change value and longitudinal change value of the target ship relative to the initial equilibrium position are determined by analyzing the point cloud data.

[0035] Further, in S5, calculating the acceleration of the ship at the last moment according to the position of the ship includes:

[0036] S51, using the current position of the target ship at time n and the position at the previous time n-1, obtain the position of the target ship at The speed of the moment;

[0037] The calculation formula is as follows:

[0038] ;

[0039] ;

[0040] Among them, X n , Y n They represent the lateral change value and longitudinal change value of the target ship’s position at the current time n, respectively. n-1 , Y n-1 They represent the lateral change value and longitudinal change value of the target ship's position at the previous moment n-1, Indicates that the target ship is The horizontal velocity at time, Indicates that the target ship is The longitudinal velocity at the time, Δt represents the time interval;

[0041] S52, using the position of the target ship at the previous moment n-1 and the position at the moment n-2, obtain the position of the target ship at The speed of the moment;

[0042] S53, Use Moment and The speed at time n, and the acceleration at time n-1;

[0043] The calculation formula is as follows:

[0044] ;

[0045] ;

[0046] in, Indicates that the target ship is The horizontal velocity at time, Indicates that the target ship is The longitudinal velocity at time, represents the lateral acceleration of the target ship at time n-1, It represents the longitudinal acceleration of the target ship at time n-1.

[0047] Furthermore, in S6, the force on the ship at the last moment is calculated according to the acceleration of the ship at the last moment, and the calculation formula is as follows:

[0048] F x n-1 =m×a x n-1 ;

[0049] F y n-1 =m×a y n-1 ;

[0050] Among them, F x n-1 Indicates the transverse force of the ship at the last moment, F y n-1 represents the longitudinal force on the ship at the previous moment, and m represents the mass of the target ship.

[0051] Furthermore, in S7, it is determined whether the difference between the estimated ship force at the previous moment and the ship force at the previous moment is less than or equal to a preset error value; if not, the wave load estimation formula is corrected, and the process returns to S1 to re-estimate the wave load; wherein the corrected wave load estimation formula includes: correcting the comprehensive coefficient of the lateral wave force and / or the comprehensive coefficient of the longitudinal wave force.

[0052] The embodiments of the present invention have the following technical effects:

[0053] The present invention combines the actually measured environmental data with the theoretical calculation, estimates the ship force at the last moment through the historical hydrological data, calculates the actual ship force at the last moment by monitoring the ship power data and taking the derivative, compares the ship force calculated at the last moment with the estimated ship force, and iteratively corrects the parameters of the estimation formula, so as to obtain a more accurate estimation formula for the moored ship force, and then calculates the ship force more accurately using the estimation formula; it is helpful to establish a safer and more effective ship mooring system, reduce the uncertainty in operation, improve the safety and reliability of the overall operation, and supplement the calculation method of the total ship force that is currently lacking in the field. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0055] Figure 1 is a flow chart of a method for calculating a moored ship load provided by an embodiment of the present invention;

[0056] Figure 2 It is a logic diagram of a method for calculating a moored ship load provided by an embodiment of the present invention;

[0057] Figure 3 It is a schematic diagram of calculating water flow load of a moored ship provided by an embodiment of the present invention;

[0058] Figure 4 is a schematic diagram of a mooring cable arrangement for a moored ship provided by an embodiment of the present invention;

[0059] Figure 5 It is a structural schematic diagram of a moored ship load calculation system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0061] The embodiment of the present invention provides a method for calculating the load of a moored ship. Figure 1is a flow chart of a method for calculating a moored ship load provided by an embodiment of the present invention. Figure 2 is a logic diagram of a method for calculating a moored ship load provided by an embodiment of the present invention, see Figure 1 and Figure 2 , including:

[0062] S1. Obtain historical hydrological conditions through the hydrological monitoring system, and calculate the wind load, water flow load and wave load on the target ship at the last moment based on the historical hydrological conditions, wind load calculation formula, water flow load calculation formula and wave load estimation formula.

[0063] Specifically, the wind load on the target ship at the last moment is calculated using the following formula:

[0064] ;

[0065] ;

[0066] Among them, F xw represents the lateral component of wind load, F yw represents the longitudinal component of wind load, A xw Indicates the lateral windward area above the water surface of the hull, A yw It represents the longitudinal windward area above the water surface of the hull, v x represents the lateral component of wind speed, v y represents the longitudinal component of wind speed, represents the wind pressure unevenness reduction coefficient, Indicates the correction factor for wind pressure height change.

[0067] Figure 3 : is a schematic diagram of calculating the water flow load of a moored ship provided by an embodiment of the present invention. Referring to the figure, the water flow load received by the target ship at the last moment is calculated, and the calculation formula is as follows:

[0068] ;

[0069] ;

[0070] Among them, F TC represents the lateral component of the flow load, F LC represents the longitudinal component of the water flow load, C TC represents the lateral component coefficient of water flow force, ρ represents the density of water, V c Indicates the average flow velocity within the ship's draft depth, L BP represents the length between vertical lines of the ship, D' represents the average draft corresponding to the loading degree of the ship, θ c Indicates the angle between the water flow direction and the longitudinal axis of the ship, F LCPrepresents the longitudinal force component caused by form drag, F LCf Represents the longitudinal component of force caused by frictional resistance.

[0071] Furthermore, the calculation formula of the longitudinal force generated by the shape resistance is as follows:

[0072] ;

[0073] Among them, C LCP represents the longitudinal shape resistance coefficient of the ship, and B represents the ship's width;

[0074] The calculation formula of the longitudinal force generated by friction resistance is as follows:

[0075] ;

[0076] Among them, C LCf represents the friction resistance coefficient of the hull, and S represents the surface area below the waterline of the ship.

[0077] Furthermore, the calculation formula of the hull friction resistance coefficient is as follows:

[0078] ;

[0079] ;

[0080] ;

[0081] Where Re is the Reynolds number of the water flow acting on the ship, ΔC LCf Indicates the hull roughness correction factor, L WL Indicates the length of the ship's waterline, C b represents the ship's square coefficient, v represents the kinematic viscosity coefficient of water, and B represents the ship's width.

[0082] Calculate the wave load on the target ship at the last moment, including:

[0083] The estimated lateral force of the wave load on the target ship at the last moment is estimated by the following formula:

[0084] ;

[0085] Among them, F x represents the estimated lateral force, x represents the comprehensive coefficient of lateral wave force, H represents the incident wave height, θ represents the wave incident angle, L represents the length between the ship columns, D represents the ship draft, and a x represents the lateral magnification factor, γ represents the seawater density, and g represents the gravitational acceleration;

[0086] The estimation formula of the estimated longitudinal force of the wave load on the target ship at the last moment is as follows:

[0087] ;

[0088] Among them, F y represents the estimated longitudinal force, y represents the comprehensive coefficient of longitudinal wave force, B represents the ship width, a y Represents the longitudinal magnification factor.

[0089] Furthermore, the comprehensive coefficient of the transverse wave force and the comprehensive coefficient of the longitudinal wave force are dimensionless numbers. Preferably, the comprehensive coefficient of the transverse wave force can be preset to 0.05, and the comprehensive coefficient of the longitudinal wave force can be preset to 0.05.

[0090] Furthermore, the calculation formula of the lateral magnification factor is as follows:

[0091] ;

[0092] Among them, T x represents the rolling period of the ship, T represents the wave period, μ x represents the lateral damping coefficient;

[0093] The calculation formula of the longitudinal magnification factor is as follows:

[0094] ;

[0095] Among them, T y represents the pitch period of the ship, μ y represents the longitudinal damping coefficient.

[0096] Furthermore, the calculation formula of the lateral damping coefficient is as follows:

[0097] ;

[0098] Where W represents the actual displacement of the ship, W f Indicates the ship's full load displacement;

[0099] The calculation formula of the longitudinal damping coefficient is as follows:

[0100] ;

[0101] Specifically, the damping coefficient is calculated based on experience. For important projects, the damping coefficient also needs to be corrected in order to find a more reasonable comprehensive coefficient and damping coefficient. In some embodiments, correction content for the damping coefficient may also be added.

[0102] S2. Measure the mooring force at the last moment through the cable force detection system.

[0103] In some embodiments, Figure 4FIG. 1 is a schematic diagram of a mooring cable arrangement for a moored vessel provided in an embodiment of the present invention. Figure 4 , is the cable number (for example, the first cable is A1B1, the second cable is A2B2, ..., and so on). The force on each cable is measured by a cable force meter. The direction of the force is along the cable. According to the angle between each cable and the ship, the transverse and longitudinal force components of each cable are calculated. Then, the transverse force components of all cables are summed up to obtain the transverse component of the mooring force, and the longitudinal force components of all cables are summed up to obtain the longitudinal component of the mooring force.

[0104] S3. According to the wind load, current load, wave load and mooring force at the previous moment, the estimated force on the ship at the previous moment is obtained.

[0105] Specifically, the estimated lateral force F of the ship at the last moment is obtained by summing the lateral component of the wind load, the lateral component of the water flow load, the estimated lateral force of the wave load, and the lateral component of the mooring force at the last moment. x n-1 ';

[0106] The estimated longitudinal force F of the ship at the last moment is obtained by summing the longitudinal component of the wind load, the longitudinal component of the water flow load, the estimated longitudinal force of the wave load and the longitudinal component of the mooring force at the last moment. y n-1 '.

[0107] In some embodiments, when the ship is docked, it will also be affected by the fender force exerted by the shore. The fender force of the ship can be calculated based on the deformation-force curve of the fender. At this time, the estimated force of the ship at the previous moment is obtained based on the wind load, water flow load, wave load, mooring force and fender force of the ship at the previous moment.

[0108] Furthermore, the deformation-stress curve of the fender is a curve graph, which is drawn by simulating the impact of a ship berthing through special testing equipment, increasing the load and recording the deformation value. The horizontal axis is the deformation percentage of the fender, and the vertical axis is the fender reaction force. The deformation can be measured by the sensor, and the corresponding reaction force will also act on the ship through interaction.

[0109] It should be noted that the addition here is not a simple numerical addition, but a vector addition with a direction, and the force here is a process force, which studies the force during the movement of the ship.

[0110] S4. Obtain the position of the ship through the ship motion monitoring system.

[0111] Specifically, the point cloud data of the target ship is measured by a 3D laser instrument, and the lateral change value X and the longitudinal change value Y of the target ship relative to the initial equilibrium position are determined by analyzing the point cloud data. The initial equilibrium position is a state in calm waters where the ship remains stationary or does not move significantly without the action of wind, waves, or currents, and the subsequent change values ​​are based on the initial equilibrium position as the reference position.

[0112] S5. Calculate the acceleration of the ship at the last moment according to the position of the ship.

[0113] Specifically include:

[0114] S51, using the current position of the target ship at time n and the position at the previous time n-1, obtain the position of the target ship at The speed of the moment;

[0115] The calculation formula is as follows:

[0116] ;

[0117] ;

[0118] Among them, X n , Y n They represent the lateral change value and longitudinal change value of the target ship’s position at the current time n, respectively. n-1 , Y n-1 They represent the lateral change value and longitudinal change value of the target ship's position at the previous moment n-1, Indicates that the target ship is The horizontal velocity at time, Indicates that the target ship is The longitudinal velocity at a certain moment, Δt represents the time interval.

[0119] S52, using the position of the target ship at the previous moment n-1 and the position at the moment n-2, obtain the position of the target ship at The speed at the moment; the calculation method is the same as S51.

[0120] S53, Use Moment and The speed at time n, and the acceleration at time n-1;

[0121] The calculation formula is as follows:

[0122] ;

[0123] ;

[0124] in, Indicates that the target ship is The horizontal velocity at time, Indicates that the target ship is The longitudinal velocity at time, represents the lateral acceleration of the target ship at time n-1, It represents the longitudinal acceleration of the target ship at time n-1.

[0125] S6. Calculate the force on the ship at the last moment based on the acceleration of the ship at the last moment.

[0126] Specifically, the calculation formula is as follows:

[0127] F x n-1 =m×a x n-1 ;

[0128] F y n-1 =m×a y n-1 ;

[0129] Among them, F x n-1 Indicates the transverse force of the ship at the last moment, F y n-1 represents the longitudinal force on the ship at the previous moment, and m represents the mass of the target ship.

[0130] S7, determine whether the difference between the estimated ship force at the previous moment and the ship force at the previous moment is less than or equal to the preset error value; if not, correct the wave load estimation formula and return to S1 to re-estimate the wave load; if so, calculate the estimated ship force at the current moment according to the current wind load calculation formula, water flow load calculation formula, wave load estimation formula and mooring force as the ship load at the current moment.

[0131] Specifically, compare F x n-1 and F x n-1 'Whether the difference between them is greater than or equal to the preset threshold, F y n-1 and F y n-1 'Whether the difference between them is greater than or equal to a preset threshold. For example, the preset threshold can be set to 5%.

[0132] If there is a difference greater than or equal to the preset threshold, the comprehensive coefficient of the transverse wave force and / or the comprehensive coefficient of the longitudinal wave force is corrected. x n-1 and F x n-1 ' is greater than or equal to the preset threshold, then the comprehensive coefficient of lateral wave force is corrected. yn-1 and F y n-1 ' is greater than or equal to the preset threshold, then the comprehensive coefficient of lateral wave force is corrected. x n-1 and F x n-1 ' is greater than or equal to the preset threshold, and F y n-1 and F y n-1 If the difference between the two is greater than or equal to the preset threshold, the comprehensive coefficient of the transverse wave force and the comprehensive coefficient of the longitudinal wave force are corrected, and the wave load of the target ship is re-estimated according to the corrected comprehensive coefficient of the transverse wave force and / or the comprehensive coefficient of the longitudinal wave force, and then the estimated force of the ship at the previous moment is recalculated until F x n-1 and F x n-1 ' is less than the preset threshold, and F y n-1 and F y n-1 ' is less than the preset threshold value, the estimated force of the ship at the current moment is calculated according to the wind load calculation formula, water flow load calculation formula, wave load estimation formula and mooring force at this time, and the ship load at the current moment is obtained.

[0133] The present invention combines the actually measured environmental data with the theoretical calculation, estimates the ship force at the last moment through the historical hydrological data, calculates the actual ship force at the last moment by monitoring the ship power data and taking the derivative, compares the ship force calculated at the last moment with the estimated ship force, and iteratively corrects the parameters of the estimation formula, so as to obtain a more accurate estimation formula for the moored ship force, and then calculates the ship force more accurately using the estimation formula; it is helpful to establish a safer and more effective ship mooring system, reduce the uncertainty in operation, improve the safety and reliability of the overall operation, and supplement the calculation method of the total ship force that is currently lacking in the field.

[0134] The embodiment of the present invention provides a system for calculating the load of a moored ship. Figure 5 is a schematic diagram of a moored ship load calculation system provided by an embodiment of the present invention, see Figure 5 The system is used to implement the above-mentioned calculation method of a moored ship load, and the system includes the following modules:

[0135] The load calculation module is used to obtain historical hydrological conditions through the hydrological monitoring system, and calculate the wind load, water flow load and wave load on the target ship at the last moment according to the historical hydrological conditions, wind load calculation formula, water flow load calculation formula and wave load estimation formula;

[0136] A mooring force acquisition module is used to measure the mooring force at the last moment through a mooring force detection system;

[0137] The ship force estimation module is connected with the load calculation module and the mooring force acquisition module, and is used to obtain the estimated ship force at the last moment according to the wind load, water flow load, wave load and mooring force at the last moment;

[0138] A ship motion monitoring module is used to obtain the position of the ship through a ship motion monitoring system;

[0139] The ship force calculation module is connected to the ship motion monitoring module and is used to calculate the acceleration of the ship at the last moment according to the position of the ship; and calculate the ship force at the last moment according to the acceleration of the ship at the last moment;

[0140] The formula correction module is connected to the ship force estimation module and the ship force calculation module, and is used to determine whether the difference between the estimated ship force at the previous moment and the ship force at the previous moment is less than or equal to the preset error value; if not, the wave load estimation formula is corrected and the wave load is re-estimated; if so, the estimated ship force at the current moment is calculated according to the current wind load calculation formula, water flow load calculation formula, wave load estimation formula and mooring force as the ship load at the current moment.

[0141] It should be noted that the terms used in the present invention are only for describing specific embodiments, rather than limiting the scope of the present application. As shown in the present specification, unless the context clearly indicates an exception, the words "one", "a", "a kind of" and / or "the" do not specifically refer to the singular, but may also include the plural. The terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of more restrictions, the elements defined by the sentence "include one..." do not exclude the presence of other identical elements in the process, method or device including the elements.

[0142] It should also be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0143] 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 replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the load of a moored ship, characterized in that: The steps include: S1. Obtain historical hydrological conditions through a hydrological monitoring system, and calculate the wind load, water flow load and wave load on the target ship at the last moment according to the historical hydrological conditions, wind load calculation formula, water flow load calculation formula and wave load estimation formula; S2, measuring the mooring force at the last moment through the cable force detection system; S3. Obtain the estimated ship force at the last moment according to the wind load, water flow load, wave load and mooring force at the last moment; S4. Obtaining the position of the ship through a ship motion monitoring system; S5. Calculate the acceleration of the ship at the last moment according to the position of the ship; S6. Calculate the force on the ship at the last moment according to the acceleration of the ship at the last moment; S7, determining whether the difference between the estimated force on the ship at the last moment and the force on the ship at the last moment is less than or equal to a preset error value; If not, the wave load estimation formula is modified and the process returns to S1 to re-estimate the wave load; If so, the estimated force on the ship at the current moment is calculated according to the current wind load calculation formula, water flow load calculation formula, wave load estimation formula and mooring force as the ship load at the current moment.

2. A method for calculating the load of a moored ship according to claim 1, characterized in that: In S1, the historical hydrological conditions are obtained through the hydrological monitoring system, and the wind load on the target ship at the last moment is calculated according to the historical hydrological conditions and the wind load calculation formula. The calculation formula is as follows: ； ； Among them, F xw represents the lateral component of wind load, F yw A represents the longitudinal component of wind load. xw Indicates the lateral windward area above the water surface of the hull, A yw It represents the longitudinal windward area above the water surface of the hull, v x represents the lateral component of wind speed, v y represents the longitudinal component of wind speed, represents the wind pressure unevenness reduction coefficient, Indicates the correction factor for wind pressure height change.

3. A method for calculating a moored ship load according to claim 1, characterized in that: In S1, the historical hydrological conditions are obtained through the hydrological monitoring system, and the water flow load received by the target ship at the last moment is calculated according to the historical hydrological conditions and the water flow load calculation formula. The calculation formula is as follows: ； ； Among them, F TC represents the lateral component of the flow load, F LC represents the longitudinal component of the water flow load, C TC represents the lateral component coefficient of water flow force, ρ represents the density of water, V c Indicates the average flow velocity within the ship's draft depth, L BP represents the length between vertical lines of the ship, D' represents the average draft corresponding to the loading degree of the ship, θ c Indicates the angle between the water flow direction and the longitudinal axis of the ship, F LCP represents the longitudinal force component caused by form resistance, F LCf Represents the longitudinal component of force caused by frictional resistance.

4. A method for calculating the load of a moored ship according to claim 1, characterized in that: In S1, historical hydrological conditions are obtained through a hydrological monitoring system, and the wave load on the target ship at the last moment is calculated according to the historical hydrological conditions and a wave load estimation formula, which specifically includes: The estimated formula for the estimated lateral force of the wave load on the target ship at the last moment is as follows: ； Among them, F x represents the estimated lateral force, x represents the comprehensive coefficient of lateral wave force, H represents the incident wave height, θ represents the wave incident angle, L represents the length between the ship columns, D represents the ship draft, and a x represents the lateral magnification factor, γ represents the seawater density, and g represents the gravitational acceleration; The estimation formula of the estimated longitudinal force of the wave load on the target ship at the last moment is as follows: ； Among them, F y represents the estimated longitudinal force, y represents the comprehensive coefficient of longitudinal wave force, B represents the ship's width, a y Represents the longitudinal magnification factor.

5. A method for calculating the load of a moored ship according to claim 1, characterized in that: In S3, based on the wind load, water flow load, wave load and mooring force at the previous moment, the estimated ship force at the previous moment is obtained, including: The estimated lateral force F of the ship at the last moment is obtained by summing the lateral component of the wind load, the lateral component of the water flow load, the estimated lateral force of the wave load and the lateral component of the mooring force at the last moment. x n-1 '; The estimated longitudinal force F of the ship at the last moment is obtained by summing the longitudinal component of the wind load, the longitudinal component of the water flow load, the estimated longitudinal force of the wave load and the longitudinal component of the mooring force at the last moment. y n-1 '.

6. A method for calculating the load of a moored vessel according to claim 5, characterized in that: In S4, obtaining the position of the ship through the ship motion monitoring system includes: The point cloud data of the target ship is measured by a 3D laser instrument, and the lateral change value and longitudinal change value of the target ship relative to the initial equilibrium position are determined by analyzing the point cloud data.

7. A method for calculating the load of a moored ship according to claim 6, characterized in that: In S5, calculating the acceleration of the ship at the last moment according to the position of the ship includes: S51, using the current position of the target ship at time n and the position at the previous time n-1, obtain the position of the target ship at The speed of the moment; The calculation formula is as follows: ； ； Among them, X n , Y n They represent the lateral change value and longitudinal change value of the target ship’s position at the current time n, respectively. n-1 , Y n -1 They represent the lateral change value and longitudinal change value of the target ship's position at the previous moment n-1, Indicates that the target ship is The horizontal velocity at time, Indicates that the target ship is The longitudinal velocity at the time, Δt represents the time interval; S52, using the position of the target ship at the previous moment n-1 and the position at the moment n-2, obtain the position of the target ship at The speed of the moment; S53, Use Moment and The speed at time n, and the acceleration at time n-1; The calculation formula is as follows: ； ； in, Indicates that the target ship is The horizontal velocity at time, Indicates that the target ship is The longitudinal velocity at time, represents the lateral acceleration of the target ship at time n-1, It represents the longitudinal acceleration of the target ship at time n-1.

8. A method for calculating the load of a moored ship according to claim 7, characterized in that: In S6, the force on the ship at the last moment is calculated according to the acceleration of the ship at the last moment, and the calculation formula is as follows: F x n-1 =m×a x n-1 ; F y n-1 =m×a y n-1 ; Among them, F x n-1 Indicates the transverse force of the ship at the last moment, F y n-1 represents the longitudinal force on the ship at the previous moment, and m represents the mass of the target ship.

9. A method for calculating a moored ship load according to claim 1, characterized in that: In S7, it is determined whether the difference between the estimated force on the ship at the last moment and the force on the ship at the last moment is less than or equal to a preset error value; If not, the wave load estimation formula is modified, and the process returns to S1 to re-estimate the wave load; wherein the modified wave load estimation formula includes: modifying the comprehensive coefficient of the lateral wave force and / or the comprehensive coefficient of the longitudinal wave force.

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