A hydrodynamic analysis method and system based on a multi-directional irregular wave spectrum

Abstract

The present invention provides a hydrodynamic analysis method and system based on a multi-directional irregular wave spectrum, which is applicable to the field of hydrodynamic analysis technology. The hydrodynamic analysis method includes multi-directional irregular wave spectrum generation, model construction, frequency domain calculation, time domain calculation, mooring cable motion calculation, integrated solution, and parallel solution. The hydrodynamic analysis system includes a body definition module, a grid generation and inspection module, a solver pre-processing module, an equation group generation module, an equation group integration and separation module, a solver solution module, a solution model opening and saving module, a grid display module, a result display module, and a script processing module. By introducing mooring cable motion calculation, more accurate hydrodynamic analysis results of floating structures are obtained. The hydrodynamic analysis method is then integrated into a computer storage medium. A tree structure is introduced to store calculation equations during the iterative calculation process. The tree structure calculation tasks are distributed to multiple threads to achieve parallel calculation, maximize the utilization of computing resources, and shorten calculation time.

Description

Technical Field

[0001] The present invention relates to a hydrodynamic analysis method and system based on multi-directional irregular wave spectrum, which are applicable to the technical field of hydrodynamic analysis. Background Art

[0002] Hydrodynamic analysis technology uses computer simulation to analyze and predict the response of floating structures. It is widely used in fields such as marine engineering, ship design, and port construction. However, the complexity and uncertainty of the marine environment present significant challenges in its application. Existing hydrodynamic analysis techniques primarily rely on building structural models and utilizing numerical calculation software to analyze the dynamic response of floating structures under varying sea conditions. These techniques typically involve frequency and time domain analysis.

[0003] Existing hydrodynamic analysis techniques can address the forces and dynamic responses of floating structures to a certain extent, but they still have some limitations. First, existing methods often impose strict restrictions on sea conditions, making them incapable of simulating complex, multi-directional, irregular waves. Second, existing methods rarely examine the dynamic characteristics of cables when analyzing the forces and responses of floating structures, ignoring their further impact on the structural response, limiting the accuracy of the calculation results. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems that the existing hydrodynamic analysis technology is insufficient in simulating complex multi-directional irregular waves and ignores the influence of the dynamic characteristics of cables on the response of floating structures. A hydrodynamic analysis method based on multi-directional irregular wave spectrum is provided. At the same time, the method is integrated into a computer storage medium and the iterative calculation process is completed by a computer. The method and system have the advantages of high calculation result accuracy and high calculation efficiency, and can be widely used in the field of hydrodynamic analysis technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A hydrodynamic analysis method based on multi-directional irregular wave spectrum, the specific implementation steps are as follows:

[0007] S101 multi-directional irregular wave spectrum generation;

[0008] The multi-directional irregular spectrum generation includes calculating the multi-directional irregular spectrum by formula (1);

[0009] S(ω,θ)=S(ω)G(ω,θ) (1)

[0010] Where ω is the frequency, θ is the direction angle of the wave, S(ω) is the spectrum, and G(ω,θ) is the directional distribution function;

[0011] S102 model construction;

[0012] The model construction includes detailed meshing of the area below the wetted surface of the floating structure, wherein the mesh type is generated using a unequal step size algorithm according to the required accuracy and computational efficiency;

[0013] S103 frequency domain calculation;

[0014] The frequency domain calculation includes solving the flow field incident potential, radiation potential, and diffraction potential based on potential flow theory and slice theory using multi-directional irregular wave spectrum and constructed models, and determining boundary conditions for these potential flows, and then calculating the fluid's additional mass A(ω), damping coefficient C, and diffraction force F. D (ω) and the radiation force F R (ω);

[0015] S104 time domain calculation;

[0016] The time domain calculation includes the additional mass, damping coefficient, wave force, diffraction force and radiation force calculated based on the frequency domain, and the corresponding time domain diffraction force F is obtained through Fourier transformation. D (t) and radiation force F R (t), calculate the dynamic response of the floating structure under the load of wave force in the time domain according to the motion equation of the floating structure (2);

[0017]

[0018] Where m is the mass of the floating body, A ∞ is the additional mass at infinite frequency, X is the displacement of the floating body, the first and second derivatives of X correspond to the velocity and acceleration of the floating body respectively, t is the floating body motion time, K is the hydrodynamic stiffness, R is the velocity pulse function, F is the wave load, including diffraction force and radiation force, F c is the water flow force of the floating body, F w is the wind resistance, F m is the force acting on the mooring rope and the hinge, F e For additional external force;

[0019] S105 calculation of mooring line motion;

[0020] The mooring line motion calculation includes establishing a mooring line motion equation (3);

[0021]

[0022] Where j is the jth section of mooring line, M is the mass, is the acceleration of the mooring line, T is the tension in the line, V is the shear force in the line, W is the weight of the line, and F' is the external hydrodynamic force;

[0023] S106 integrated solution;

[0024] The integrated solution includes the following steps:

[0025] 1) Establish a general structural dynamics equation model,

[0026]

[0027] Where m, c and k are the n×n order mass matrix, damping matrix and stiffness matrix respectively, d and f are the n×1 order additional term matrix and external load matrix respectively;

[0028] 2) According to the preset order of the equations, establish the index calculation function f row (i) and f col (j), f row (i) = s k +i,f col (j) = s k +j,s k Indicates the starting assembly position for storing the kth equation, s k =d1+d2+...+d k-1 , d k-1 is the number of degrees of freedom of the k-1th equation;

[0029] 3) For each cable, according to the preset number of nodes N, a coefficient matrix with 3N degrees of freedom is established, and the nodes are arranged in order from one end of the cable to the other end. The f of the kth node is row (i) = f col (j) = 3k;

[0030] 4) Sub-equation assembly: assemble the matrix elements for each equation.

[0031] M(f row (i),f col (j))=m(i,j) (5)

[0032] C(f row (i),f col (j))=c(i,j) (6)

[0033] K(f row (i),f col (j))=k(i,j) (7)

[0034] D(f row (i),0)=d(i,0) (8)

[0035] F(f row (i),0)=f(i,0) (9)

[0036] Construct the total calculation equation,

[0037]

[0038] 5) Establish a multi-level equation assembly method in a tree structure, and assemble the constructed total equation as a single equation into another total equation;

[0039] 6) Each equation contains multiple nodes, and solves the node positions x; The mooring cable connects the top node to the parent float hydrodynamic equation to achieve real-time solution of the top node boundary condition at each calculation step. x according to the center of gravity x is obtained by coordinate transformation (11);

[0040]

[0041] Where [X, Y, Z] T is the position coordinate of any point, [X g ,Y g ,Z g ] T is the barycentric coordinate, θ x represents the rotation angle around the x-axis, θ y Represents the rotation angle around the y-axis, θ z Indicates the rotation angle around the z-axis;

[0042] 7) Initialize parameters and iteratively solve multi-level equations;

[0043] S107 parallel solution;

[0044] The parallel solution includes assembling all equations into a tree structure, associating two related equations into the same tree node, and each solution includes multiple tree root nodes; according to a preset number of threads, each thread evenly shares the tree root nodes, and solves all equations under the tree root nodes to which the thread belongs;

[0045] Furthermore, in step S101, the frequency spectrum adopts the improved JONSWAP spectrum proposed by Goda, and the directional distribution function adopts the directional distribution function proposed by Longuet-Higgins.

[0046] A hydrodynamic analysis system based on multi-directional irregular wave spectrum, specifically including the following modules:

[0047] 1) Body definition module;

[0048] The body definition module inputs the attached body data to generate a cuboid, a cylinder, or an arbitrary body; selects multiple bodies to generate a collection of multiple body objects, and implements the functions of adding, deleting, modifying, and querying floating bodies;

[0049] 2) Mesh generation and checking module;

[0050] The grid generation and checking module generates grids by using equal-step uniform grid generation and unequal-step grid generation algorithms according to two groups of opposite sides corresponding to the quadrilateral;

[0051] 3) Solver pre-processing module;

[0052] The solver pre-processing module includes grid set generation and solution set generation functions to generate parallel solution set data required for the solution process;

[0053] 4) Equation generation module;

[0054] The equation group generation module includes data input and assembly of a single equation; for a single equation group, a mapping is established from the hydrodynamic equation and the mooring cable equation to the single equation by establishing a mapping method;

[0055] 5) Equation system integration and separation module;

[0056] The equation group integration and separation module includes equation group index generation, assembly and separation;

[0057] 6) Solver solution module;

[0058] The solver solution module realizes the functions of monitoring the solution process status and outputting, starting, pausing and restarting;

[0059] 7) Solve model opening and saving module;

[0060] The solution model opening and saving module realizes the opening and saving functions of the grid data of the calculation area and the time history data of the solution process components;

[0061] 8) Grid display module;

[0062] The grid display module performs three-dimensional display of grid point components, grid connections, etc., and includes grid selection and display functions;

[0063] 9) Result display module;

[0064] The result display module includes the result display of any set section of the velocity stress component and the result display of the entire calculation area;

[0065] 10) Script processing module;

[0066] The script processing module includes script generation and execution functions for modules such as body definition, material definition and binding, grid generation and checking, solver pre-processing, solver solution, solution model opening and saving, grid display, and result display; and realizes the functions of creating, deleting, modifying and saving scripts.

[0067] Furthermore, the system also includes a computer-readable storage medium, wherein the computer-readable storage medium includes a stored computer program, and when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute any of the above methods.

[0068] The beneficial effects of the present invention are as follows: by referencing multi-directional irregular wave spectra during frequency domain analysis, dynamic response analysis of floating structures under more complex sea conditions is achieved; by introducing mooring cable motion calculations and then substituting the calculation results into the floating structure for further iterative calculations, more accurate hydrodynamic analysis results of the floating structure can be obtained; the hydrodynamic analysis method is then integrated into a computer storage medium, the entire solution process is completed by a computer, and a tree structure is introduced to store calculation equations during the iterative calculation process, and the tree structure calculation tasks are distributed to multiple threads to achieve parallel calculations, which can maximize the use of computing resources, shorten the calculation time, and complete efficient calculations. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 It is a flow chart of the hydrodynamic analysis method based on multi-directional irregular wave spectrum of the present invention.

[0070] Figure 2 It is a structural diagram of the hydrodynamic analysis system based on multi-directional irregular wave spectrum of the present invention. DETAILED DESCRIPTION

[0071] The following describes in detail specific embodiments of the present invention in conjunction with the accompanying drawings. It should be understood that the specific embodiments provided herein are intended only to illustrate and explain the present invention and are not intended to limit the present invention. It should be noted that many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention may also have other embodiments and variations thereof. Therefore, the scope of protection of the present invention is not limited by the specific embodiments disclosed below.

[0072] Example 1, a hydrodynamic analysis method based on multi-directional irregular wave spectrum, the specific implementation process is as follows:

[0073] S101 multi-directional irregular wave spectrum generation;

[0074] The multi-directional irregular spectrum generation includes calculating the multi-directional irregular spectrum by formula (1);

[0075] S(ω,θ)=S(ω)G(ω,θ) (1)

[0076] Wherein, ω is the frequency, θ is the direction angle of the wave, S(ω) is the spectrum, and G(ω,θ) is the directional distribution function. The spectrum adopts the improved JONSWAP spectrum proposed by Goda, and the directional distribution function adopts the directional distribution function proposed by Longuet-Higgins.

[0077] S102 model construction;

[0078] The model construction includes detailed meshing of the area below the wetted surface of the floating structure, wherein the mesh type is generated using a unequal step size algorithm according to the required accuracy and computational efficiency;

[0079] S103 frequency domain calculation;

[0080] The frequency domain calculation includes solving the flow field incident potential, radiation potential, and diffraction potential based on potential flow theory and slice theory using multi-directional irregular wave spectrum and constructed models, and determining boundary conditions for these potential flows, and then calculating the fluid's additional mass A(ω), damping coefficient C, and diffraction force F. D (ω) and the radiation force F R (ω);

[0081] S104 time domain calculation;

[0082] The time domain calculation includes the additional mass, damping coefficient, wave force, diffraction force and radiation force calculated based on the frequency domain, and the corresponding time domain diffraction force F is obtained through Fourier transformation. D (t) and radiation force F R (t), calculate the dynamic response of the floating structure under the load of wave force in the time domain according to the motion equation of the floating structure (2);

[0083]

[0084] Where m is the mass of the floating body, A ∞ is the additional mass at infinite frequency, X is the displacement of the floating body, the first and second derivatives of X correspond to the velocity and acceleration of the floating body respectively, t is the floating body motion time, K is the hydrodynamic stiffness, R is the velocity pulse function, F is the wave load, including diffraction force and radiation force, F c is the water flow force of the floating body, F w is the wind resistance, F m is the force acting on the mooring rope and the hinge, F e For additional external force;

[0085] S105 calculation of mooring line motion;

[0086] The mooring line motion calculation includes establishing a mooring line motion equation (3);

[0087]

[0088] Where j is the jth section of mooring line, M is the mass, is the acceleration of the mooring line, T is the tension in the line, V is the shear force in the line, W is the weight of the line, and F' is the external hydrodynamic force;

[0089] S106 integrated solution;

[0090] The integrated solution includes the following steps:

[0091] 1) Establish a general structural dynamics equation model,

[0092]

[0093] Where m, c and k are the n×n order mass matrix, damping matrix and stiffness matrix respectively, d and f are the n×1 order additional term matrix and external load matrix respectively;

[0094] 2) According to the preset order of the equations, establish the index calculation function f row (i) and f col (j), f row (i) = s k +i,f col (j) = s k +j,s k Indicates the starting assembly position for storing the kth equation, s k =d1+d2+...+d k-1 , d k-1 is the number of degrees of freedom of the k-1th equation;

[0095] 3) For each cable, according to the preset number of nodes N, a coefficient matrix with 3N degrees of freedom is established, and the nodes are arranged in order from one end of the cable to the other end. The f of the kth node is row (i) = f col (j) = 3k;

[0096] 4) Sub-equation assembly: assemble the matrix elements for each equation.

[0097] M(f row (i),f col (j))=m(i,j) (5)

[0098] C(f row (i),f col (j))=c(i,j) (6)

[0099] K(f row (i),f col (j))=k(i,j) (7)

[0100] D(f row (i),0)=d(i,0) (8)

[0101] F(f row (i),0)=f(i,0) (9)

[0102] Construct the total calculation equation,

[0103]

[0104] 5) Establish a multi-level equation assembly method in a tree structure, and assemble the constructed total equation as a single equation into another total equation;

[0105] 6) Each equation contains multiple nodes, and solves the node positions x; The mooring cable connects the top node to the parent float hydrodynamic equation to achieve real-time solution of the top node boundary condition at each calculation step. x according to the center of gravity x is obtained by coordinate transformation (11);

[0106]

[0107] Where [X, Y, Z] T is the position coordinate of any point, [X g ,Y g ,Z g ] T is the barycentric coordinate, θ x represents the rotation angle around the x-axis, θ y Represents the rotation angle around the y-axis, θ z Indicates the rotation angle around the z-axis;

[0108] 7) Initialize parameters and iteratively solve multi-level equations;

[0109] S107 parallel solution;

[0110] The parallel solution includes assembling all equation groups according to a tree structure. For two related equations, they are associated with the same tree node, and each solution includes multiple root nodes; according to the preset number of threads, each thread is evenly divided into root nodes, and all equations under the root nodes to which the thread belongs are solved.

[0111] Example 2, a hydrodynamic analysis system based on multi-directional irregular wave spectrum, specifically includes the following modules:

[0112] 1) Body definition module;

[0113] The body definition module inputs the attached body data to generate a cuboid, a cylinder, or an arbitrary body; selects multiple bodies to generate a collection of multiple body objects, and implements the functions of adding, deleting, modifying, and querying floating bodies;

[0114] 2) Mesh generation and checking module;

[0115] The grid generation and checking module generates grids by using equal-step uniform grid generation and unequal-step grid generation algorithms according to two groups of opposite sides corresponding to the quadrilateral;

[0116] 3) Solver pre-processing module;

[0117] The solver pre-processing module includes grid set generation and solution set generation functions to generate parallel solution set data required for the solution process;

[0118] 4) Equation generation module;

[0119] The equation group generation module includes data input and assembly of a single equation; for a single equation group, a mapping is established from the hydrodynamic equation and the mooring cable equation to the single equation by establishing a mapping method;

[0120] 5) Equation system integration and separation module;

[0121] The equation group integration and separation module includes equation group index generation, assembly and separation;

[0122] 6) Solver solution module;

[0123] The solver solution module realizes the functions of monitoring the solution process status and outputting, starting, pausing and restarting;

[0124] 7) Solve model opening and saving module;

[0125] The solution model opening and saving module realizes the opening and saving functions of the grid data of the calculation area and the time history data of the solution process components;

[0126] 8) Grid display module;

[0127] The grid display module performs three-dimensional display of grid point components, grid connections, etc., and includes grid selection and display functions;

[0128] 9) Result display module;

[0129] The result display module includes the result display of any set section of the velocity stress component and the result display of the entire calculation area;

[0130] 10) Script processing module;

[0131] The script processing module includes script generation and execution functions for modules such as body definition, material definition and binding, grid generation and checking, solver pre-processing, solver solution, solution model opening and saving, grid display, and result display; and realizes the functions of creating, deleting, modifying and saving scripts.

[0132] In this embodiment, the system further includes a computer-readable storage medium, wherein the computer-readable storage medium includes a stored computer program, and when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute any of the above methods.

[0133] In summary, the present invention is based on a hydrodynamic analysis method and system of multi-directional irregular wave spectra, which realizes the dynamic response analysis of floating structures under more complex sea conditions, and obtains more accurate hydrodynamic analysis results of floating structures by introducing mooring cable motion calculations. Then, the hydrodynamic analysis method is integrated into a computer storage medium, and a tree structure is introduced to store calculation equations in the iterative calculation process. The tree structure calculation tasks are distributed to multiple threads to realize parallel calculation, maximize the utilization of computing resources, and shorten the calculation time. This method and system have the advantages of high calculation result accuracy and high calculation efficiency, and can be widely used in the field of hydrodynamic analysis technology.

[0134] It should be understood that the above embodiments are one or more embodiments of the present invention, and there are many other embodiments and variations thereof based on the present invention; the variations and modifications made by ordinary technicians in this industry through the present invention without making groundbreaking innovations all fall within the scope of protection of the present invention.

Claims

1. A hydrodynamic analysis method based on multi-directional irregular wave spectrum, characterized in that It includes the following seven steps: S101 multi-directional irregular wave spectrum generation; The multi-directional irregular spectrum generation includes calculating the multi-directional irregular spectrum by formula (1); S(ω,θ)=S(ω)G(ω,θ) (1) Where ω is the frequency, θ is the direction angle of the wave, S(ω) is the spectrum, and G(ω,θ) is the directional distribution function; S102 model construction; The model construction includes detailed meshing of the area below the wetted surface of the floating structure, wherein the mesh type is generated using a unequal step size algorithm according to the required accuracy and computational efficiency; S103 frequency domain calculation; The frequency domain calculation includes solving the flow field incident potential, radiation potential, and diffraction potential based on potential flow theory and slice theory using multi-directional irregular wave spectrum and constructed models, and determining boundary conditions for these potential flows, and then calculating the fluid's additional mass A(ω), damping coefficient C, and diffraction force F. D (ω) and the radiation force F R (ω); S104 time domain calculation; The time domain calculation includes the additional mass, damping coefficient, wave force, diffraction force and radiation force calculated based on the frequency domain, and the corresponding time domain diffraction force F is obtained through Fourier transformation. D (t) and radiation force F R (t), calculate the dynamic response of the floating structure under the load of wave force in the time domain according to the motion equation of the floating structure (2); Where m is the mass of the floating body, A ∞ is the additional mass at infinite frequency, X is the displacement of the floating body, the first and second derivatives of X correspond to the velocity and acceleration of the floating body respectively, t is the floating body motion time, K is the hydrodynamic stiffness, R is the velocity pulse function, F is the wave load, including diffraction force and radiation force, F c is the water flow force of the floating body, F w is the wind resistance, F m is the force acting on the mooring rope and the hinge, F e For additional external force; S105 calculation of mooring line motion; The mooring line motion calculation includes establishing a mooring line motion equation (3); Where j is the jth section of mooring line, M is the mass, is the acceleration of the mooring line, T is the tension in the line, V is the shear force in the line, W is the weight of the line, and F' is the external hydrodynamic force; S106 integrated solution; The integrated solution includes the following steps: 1) Establish a general structural dynamics equation model, Where m, c and k are the n×n order mass matrix, damping matrix and stiffness matrix respectively, d and f are the n×1 order additional term matrix and external load matrix respectively; 2) According to the preset order of the equations, establish the index calculation function f row (i) and f col (j), f row (i) = s k +i,f col (j) = s k +j,s k Indicates the starting assembly position for storing the kth equation, s k =d1+d2+...+d k-1 , d k-1 is the number of degrees of freedom of the k-1th equation; 3) For each cable, according to the preset number of nodes N, a coefficient matrix with 3N degrees of freedom is established, and the nodes are arranged in order from one end of the cable to the other end. The f of the kth node is row (i) = f col (j) = 3k; 4) Sub-equation assembly: assemble the matrix elements for each equation. M(f row (i),f col (j))=m(i,j) (5) C(f row (i),f col (j))=c(i,j) (6) K(f row (i),f col (j))=k(i,j) (7) D(f row (i),0)=d(i,0) (8) F(f row (i),0)=f(i,0) (9) Construct the total calculation equation, 5) Establish a multi-level equation assembly method in a tree structure, and assemble the constructed total equation as a single equation into another total equation; 6) Each equation contains multiple nodes, and solves the node positions x; The mooring cable connects the top node to the parent float hydrodynamic equation to achieve real-time solution of the top node boundary condition at each calculation step. x according to the center of gravity x is obtained by coordinate transformation (11); Where [X, Y, Z] T is the position coordinate of any point, [X g ,Y g ,Z g ] T is the barycentric coordinate, θ x represents the rotation angle around the x-axis, θ y Represents the rotation angle around the y-axis, θ z Indicates the rotation angle around the z-axis; 7) Initialize parameters and iteratively solve multi-level equations; S107 parallel solution; The parallel solution includes assembling all equation groups according to a tree structure. For two related equations, they are associated with the same tree node, and each solution includes multiple root nodes; according to the preset number of threads, each thread is evenly divided into root nodes, and all equations under the root nodes to which the thread belongs are solved.

2. The hydrodynamic analysis method based on multi-directional irregular wave spectrum according to claim 1, characterized in that: In step S101 , the frequency spectrum adopts the improved JONSWAP spectrum proposed by Goda, and the directional distribution function adopts the directional distribution function proposed by Longuet-Higgins.

3. A hydrodynamic analysis system based on multi-directional irregular wave spectrum, characterized by Contains the following modules: 1) Body definition module; The body definition module inputs the attached body data to generate a cuboid, a cylinder, or an arbitrary body; selects multiple bodies to generate a collection of multiple body objects, and implements the functions of adding, deleting, modifying, and querying floating bodies; 2) Mesh generation and checking module; The grid generation and checking module generates grids by using equal-step uniform grid generation and unequal-step grid generation algorithms according to two groups of opposite sides corresponding to the quadrilateral; 3) Solver pre-processing module; The solver pre-processing module includes grid set generation and solution set generation functions to generate parallel solution set data required for the solution process; 4) Equation generation module; The equation group generation module includes data input and assembly of a single equation; for a single equation group, a mapping is established from the hydrodynamic equation and the mooring cable equation to the single equation by establishing a mapping method; 5) Equation system integration and separation module; The equation group integration and separation module includes equation group index generation, assembly and separation; 6) Solver solution module; The solver solution module realizes the functions of monitoring the solution process status and outputting, starting, pausing and restarting; 7) Solve model opening and saving module; The solution model opening and saving module realizes the opening and saving functions of the grid data of the calculation area and the time history data of the solution process components; 8) Grid display module; The grid display module performs three-dimensional display of grid point components, grid connections, etc., and includes grid selection and display functions; 9) Result display module; The result display module includes the result display of any set section of the velocity stress component and the result display of the entire calculation area; 10) Script processing module; The script processing module includes script generation and execution functions for modules such as body definition, material definition and binding, mesh generation and checking, solver pre-processing, solver solution, solution model opening and saving, mesh display, and result display; Implement the functions of creating, deleting, modifying and saving scripts.

4. The hydrodynamic system based on multi-directional irregular wave spectrum according to claim 2, characterized in that: The invention comprises a computer-readable storage medium, wherein the computer-readable storage medium comprises a stored computer program, and when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 3.

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