Method for forecasting and simulating heaving and pitching motion of series combined ship in regular waves

Abstract

The invention belongs to the technical field of ship attitude forecasting, and particularly discloses a heaving and pitching motion forecasting simulation method of a series combined ship in regular waves, which comprises the following steps: establishing heaving and pitching motion mathematical models of the series combined ship in the regular waves, the heaving and pitching motion mathematical model is used for describing the physical characteristics and the motion law of the series combined ship; resolving the motion mathematical model to obtain heaving and pitching motion historical data of the series combined ship; based on the motion historical data, training a long short-term memory (LSTM) network prediction model; and inputting real-time heaving and pitching motion data of the series combined ship into the trained LSTM prediction model to obtain heaving and pitching motion data of the next moment output by the trained LSTM prediction model. The method can improve the prediction accuracy of heaving and pitching motion of the series combined ship.

Description

Technical Field

[0001] The present application belongs to the technical field of ship attitude prediction, and more specifically, relates to a simulation method for predicting the heave and pitch motion of a series-connected ship in regular waves. Background Art

[0002] With the continued development of marine resources, the role of ships in marine engineering is becoming increasingly prominent. In particular, in offshore operations, maritime transportation, and marine structure construction, ships serve not only as essential means of transportation but also as critical operating platforms. However, while operating at sea, ships are often affected by natural environmental factors such as waves, wind, and currents, particularly heave and pitch motions, which directly impact ship stability and operational efficiency.

[0003] Existing ship motion simulation systems mostly focus on simulating the motion of single-hull vessels. There is no comprehensive solution for predicting the motion of flexibly connected tandem composite vessels, particularly the heave and pitch motions. Due to the unique structural characteristics of flexibly connected tandem composite vessels, their behavior in waves differs significantly from that of single-hull vessels. Consequently, existing ship motion simulation methods have low accuracy in predicting the heave and pitch motions of tandem composite vessels. Summary of the Invention

[0004] In response to the defects of the existing technology, the purpose of this application is to provide a simulation method for predicting the heave and pitch motion of a series-connected ship in regular waves, aiming to solve the problem that the existing ship motion simulation method has low prediction accuracy for the heave and pitch motion of a series-connected ship.

[0005] To achieve the above objectives, in a first aspect, the present application provides a method for predicting and simulating the heave and pitch motion of a tandem-connected ship in regular waves, comprising: Establishing a mathematical model of heaving and pitching motions of a tandem combination ship in regular waves, wherein the mathematical model of heaving and pitching motions is used to describe the physical characteristics and motion laws of the tandem combination ship; Solving the motion mathematical model to obtain historical data of heave and pitch motion of the series-connected ships; Based on the movement history data, a Long Short-Term Memory (LSTM) prediction model is trained; The real-time heaving and pitching motion data of the series-connected ship are input into the trained LSTM prediction model to obtain the heaving and pitching motion data of the next moment output by the trained LSTM prediction model.

[0006] The present application carries out modeling and simulation of the motion of tandem combination ships in regular waves, and establishes a mathematical model of the heaving and pitching motion of tandem combination ships in regular waves. Different from the modeling and simulation of the motion of a single ship, each flexible articulated unit plays the role of transmitting force. By separately calculating the heaving force and pitching moment acting on a single ship, the force acting on the articulated combination of multiple ships in the waves is analyzed, the motion mathematical model is solved in real time, and the obtained motion history data is used to train the LSTM prediction model. Finally, the trained LSTM prediction model is used to predict the motion of the tandem combination ships, thereby improving the prediction accuracy of the heaving and pitching motion of the tandem combination ships.

[0007] According to a method for predicting and simulating the heave and pitch motion of a series-connected ship in regular waves provided by the present application, establishing a mathematical model of the heave and pitch motion of the series-connected ship in regular waves includes: Establish a mathematical model of the serial combined ship coordinate system and the heave and pitch motion of a single hull in regular waves; Based on the serially combined ship coordinate system, calculating the sum of the bare hull hydrodynamic forces of all hulls, the sum of the bare hull moments of all hulls, the sum of the propeller forces of all hulls, the sum of the propeller moments of all hulls, the sum of the wave forces of all hulls, the sum of the wave moments of all hulls, and the forces and moments of the hinges; Based on the mathematical model of the heaving and pitching motion of the single hull in regular waves, the sum of the bare hull hydrodynamics of all hulls, the sum of the bare hull moments of all hulls, the sum of the propeller forces of all hulls, the sum of the propeller moments of all hulls, the sum of the wave forces of all hulls, the sum of the wave moments of all hulls, and the forces and moments of the hinges, a mathematical model of the heaving and pitching motion of the series combination ship in regular waves is established.

[0008] This application analyzes the forces acting on a hinged assembly of multiple ships in waves by separately calculating the heave force and pitch moment acting on a single ship, and establishes a motion mathematical model to improve the accuracy of the final motion prediction.

[0009] According to a simulation method for predicting the heave and pitch motion of a tandem-combined ship in regular waves provided by the present application, the calculation process of the sum of the wave forces of all hulls and the sum of the wave moments of all hulls includes: Calculate the radiation force, diffraction force and incident waves of a monohull; Based on the radiation force, diffraction force and incident wave of the monohull, the sum of the wave forces of all the hulls and the sum of the wave moments of all the hulls are calculated.

[0010] According to a simulation method for predicting the heave and pitch motion of a tandem-combined ship in regular waves provided by the present application, the LSTM prediction model is trained based on the motion history data, including: Preprocessing the motion history data; Extracting feature data from preprocessed motion history data; Constructing the feature data into a time series format suitable for the LSTM prediction model; Use feature data in a time series format suitable for the LSTM forecasting model to train the LSTM forecasting model.

[0011] This application preprocesses the motion history data to extract features and converts the data into a time series format suitable for the LSTM prediction model, so that the training effect of the LSTM prediction model is better and the final prediction accuracy is improved.

[0012] According to a method for predicting and simulating the heave and pitch motion of a tandem combination ship in regular waves provided by the present application, solving the motion mathematical model to obtain historical data of the heave and pitch motion of the tandem combination ship includes: The motion mathematical model is solved using a fourth-order Runge-Kutta integral to obtain the heave and pitch motion history data of the series-connected ships.

[0013] This application uses the fourth-order Runge-Kutta integral to solve the motion mathematical model to improve the solution accuracy and stability.

[0014] According to a method for predicting and simulating the heave and pitch motion of a tandem-combined ship in regular waves, the present application further includes: The trained LSTM prediction model is evaluated.

[0015] In a second aspect, the present application provides a device for predicting and simulating the heave and pitch motion of a series-connected ship in regular waves, comprising: An establishment module is used to establish a mathematical model of the heave and pitch motion of the series-connected ship in regular waves, wherein the mathematical model of the heave and pitch motion is used to describe the physical characteristics and motion laws of the series-connected ship; A solving module, used for solving the motion mathematical model to obtain the heave and pitch motion history data of the series-connected ship; A training module, configured to train an LSTM prediction model based on the motion history data; The acquisition module is used to input the real-time heaving and pitching motion data of the series-connected ship into the trained LSTM prediction model, and obtain the heaving and pitching motion data of the next moment output by the trained LSTM prediction model.

[0016] In a third aspect, the present application provides an electronic device comprising: at least one memory for storing programs; and at least one processor for executing the programs stored in the memory. When the programs stored in the memory are executed, the processor is used to execute the method for simulating the prediction of the heave and pitch motion of a series-combined ship in regular waves as described in the first aspect or any possible implementation of the first aspect.

[0017] In a fourth aspect, the present application provides a computer-readable storage medium storing a computer program. When the computer program runs on a processor, the processor executes the method for simulating the prediction of the heave and pitch motion of a series-combined ship in regular waves as described in the first aspect or any possible implementation of the first aspect.

[0018] In a fifth aspect, the present application provides a computer program product, which, when running on a processor, enables the processor to execute the method for simulating the prediction of the heave and pitch motion of a series-combined ship in regular waves as described in the first aspect or any possible implementation of the first aspect.

[0019] It can be understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0020] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies: The present application carries out modeling and simulation of the motion of tandem combination ships in regular waves, and establishes a mathematical model of the heaving and pitching motion of tandem combination ships in regular waves. Different from the modeling and simulation of the motion of a single ship, each flexible articulated unit plays the role of transmitting force. By separately calculating the heaving force and pitching moment acting on a single ship, the force acting on the articulated combination of multiple ships in the waves is analyzed, the motion mathematical model is solved in real time, and the obtained motion history data is used to train the LSTM prediction model. Finally, the trained LSTM prediction model is used to predict the motion of the tandem combination ships, thereby improving the prediction accuracy of the heaving and pitching motion of the tandem combination ships. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 This is a flow chart of a simulation method for predicting heave and pitch motion of a series-connected ship in regular waves provided by an embodiment of the present application; Figure 2 Schematic diagram of the LSTM prediction model provided in the embodiment of the present application; Figure 3 Schematic diagram of a serially combined ship coordinate system provided in an embodiment of the present application; Figure 4 Schematic diagram of a ship-borne coordinate system with the center of a single ship as the coordinate origin provided by an embodiment of the present application; Figure 5 is a schematic diagram of force transmission of a hinge provided in an embodiment of the present application; Figure 6 is a schematic diagram of a spatial rectangular coordinate system of a hinge provided in an embodiment of the present application; Figure 7 is a schematic diagram of a user interaction interface provided in an embodiment of the present application; Figure 8 1 is a schematic structural diagram of a device for predicting and simulating the heave and pitch motion of a series-connected ship in regular waves provided by an embodiment of the present application; Figure 9 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0024] The term "and / or" as used herein describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. The symbol " / " as used herein indicates that the related objects are in an "or" relationship, for example, A / B means either A or B.

[0025] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0026] In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more, for example, multiple processing units means two or more processing units, etc.; multiple elements means two or more elements, etc.

[0027] Next, combine Figure 1-Figure 7The simulation method for predicting the heave and pitch motion of a series-connected ship in regular waves provided in an embodiment of the present application is introduced.

[0028] Figure 1 FIG. 1 is a flow chart of a simulation method for predicting heave and pitch motion of a series-connected ship in regular waves provided by an embodiment of the present application. Figure 1 As shown, the method includes the following steps: Step 100, establishing a mathematical model of heave and pitch motion of the series-connected ship in regular waves, wherein the mathematical model of heave and pitch motion is used to describe the physical characteristics and motion laws of the series-connected ship; Firstly, a motion mathematical model is established to describe the physical characteristics and motion laws of the series-connected ships.

[0029] Step 110, solving the motion mathematical model to obtain the heave and pitch motion history data of the series-connected ship; Optionally, this application does not limit the solution method.

[0030] Step 120: training an LSTM prediction model based on the historical motion data; The solved historical data of heave and pitch motion of the series combination ship are used to train the LSTM prediction model, and the trained LSTM prediction model is obtained and used to predict the motion state of the series combination ship.

[0031] Figure 2 is a schematic diagram of the LSTM prediction model provided in the embodiment of the present application, such as Figure 2 As shown in the figure, an LSTM prediction model is established and its network architecture is designed, including determining the number of hidden layers and the number of units in each hidden layer. The LSTM prediction model consists of four parts: a forget gate, an input gate, an output gate, and the unit state. When the LSTM neural network receives input, it has three input parameters: the current input value, the previous output value, and the previous unit state. When it outputs, it has two output parameters: the current output value and the current unit state.

[0032] The role of the forget gate determines How much of the cell state needs to be retained until the current moment? The mathematical expression is as follows:

[0033] in, is the vector weight, is the bias vector, the gate will read and Two input values, through the activation function (sigmoid function) controls the output of a value between 0 and 1 to , 0 means completely discard , 1 represents full retention .

[0034] The role of the input gate determines How much new data needs to be saved to the cell state , the mathematical expression is as follows:

[0035] in, and is the vector weight, and is the bias vector, and the gate requires two steps to achieve the new cell state , the first step is to calculate Decide what information needs to be updated and then calculate the current state , the second step is to calculate the new unit state at the current moment .

[0036] The function of the output gate is to control the unit state How much needs to be output to , the mathematical expression is as follows:

[0037] in, is the vector weight, is the bias vector, and the gate is activated by the activation function Determine unit status The output part of , then by Determine the final output value .

[0038] In step 130, the real-time heave and pitch motion data of the series-connected ship are input into the trained LSTM prediction model to obtain the heave and pitch motion data of the next moment output by the trained LSTM prediction model.

[0039] The trained LSTM prediction model is used to predict the heave and pitch motion of new input heave and pitch data.

[0040] The present application provides a method for predicting and simulating the heaving and pitching motions of a series-assembled ship in regular waves, carries out modeling and simulation of the motion of the series-assembled ship in regular waves, and establishes a mathematical model of the heaving and pitching motions of the series-assembled ship in regular waves. Unlike the modeling and simulation of the motion of a single ship, each flexible articulated unit plays the role of transmitting force. By separately calculating the heaving force and pitching moment exerted on a single ship, the force exerted on the articulated combination of multiple ships in the waves is analyzed, the motion mathematical model is solved in real time, and the obtained motion history data is used to train an LSTM prediction model. Finally, the trained LSTM prediction model is used to predict the motion of the series-assembled ship, thereby improving the prediction accuracy of the heaving and pitching motions of the series-assembled ship.

[0041] In some embodiments, step 100 specifically includes: Step 1001, establishing a mathematical model of the heave and pitch motion of a series combined ship coordinate system and a single hull in regular waves; Step 1002: Calculate the sum of the bare hull hydrodynamic forces of all hulls, the sum of the bare hull moments of all hulls, the sum of the propeller forces of all hulls, the sum of the propeller moments of all hulls, the sum of the wave forces of all hulls, the sum of the wave moments of all hulls, and the forces and moments of the hinges based on the serial combined ship coordinate system. Step 1003, based on the mathematical model of the heave and pitch motion of a single hull in regular waves, the sum of the bare hull hydrodynamics of all hulls, the sum of the bare hull moments of all hulls, the sum of the propeller forces of all hulls, the sum of the propeller moments of all hulls, the sum of the wave forces of all hulls, the sum of the wave moments of all hulls, and the forces and moments of the hinges, a mathematical model of the heave and pitch motion of the series combination ship in regular waves is established.

[0042] Figure 3 This is a schematic diagram of the serial combination ship coordinate system provided by the embodiment of the present application, such as Figure 3 As shown, the serially coupled ships (combinations) are flexibly connected, and the geometric center of the serially coupled ships is used as the coordinate origin of the serially coupled ships' coordinate system.

[0043] Calculating the wave forces acting on a tandem-assembled vessel in waves is a complex process that requires consideration of multiple factors, including wave characteristics, hull geometry, hull physical properties, and the interaction between the hull and the waves. Furthermore, the forces acting on the assembly in regular waves must be considered. Since the assembly is linked by hinges, it cannot be treated as a single rigid body. Therefore, the forces acting on each hull can be calculated separately, taking into account the role of the hinges in force transmission.

[0044] Figure 4 This is a schematic diagram of a ship-borne coordinate system provided by an embodiment of the present application with the center of a single ship as the coordinate origin, such as Figure 4As shown in the figure, a ship-borne coordinate system with the center of a single ship as the coordinate origin and a spatial rectangular coordinate system of each hinged member are established, and then a mathematical model of the heave and pitch motion of a single hull in regular waves is established as follows:

[0045] in, +1 for the +1 ship, For ships quality, For ships z Directional additional mass, It is a ship exist z The heave acceleration in the direction It is a ship Around y The pitch angular acceleration in the direction, is the moment of inertia about the y-axis, is the additional moment of inertia about the y-axis, For bare hull hydrodynamics, is the propeller force, is the wave force, is the vertical force from ship i transmitted by the flexible hinge, is the bare hull moment, is the propeller torque, is the wave moment, Z is the component of the resultant force acting on the center of gravity in the z-axis direction, M is the y-axis component of the resultant moment about the center of gravity, and g is the acceleration due to gravity.

[0046] Figure 5 This is a schematic diagram of the hinge force transmission provided by the embodiment of the present application, the vertical force from the i ship transmitted by the flexible hinge like Figure 5 shown.

[0047] The hydrodynamic force on the bare hull is composed of inertial hydrodynamic force and viscous hydrodynamic force, and the moment on the bare hull is composed of inertial moment and viscous moment. The inertial hydrodynamic force and moment of the bare hull are calculated as follows:

[0048] Where, 、 、 is the additional mass, is the ship's forward speed, is the ship's transverse speed, is the ship's rolling angular velocity, is the ship's pitching angular velocity, is the ship's bow angular velocity, is the ship's heaving speed, is the ship's heaving acceleration, is the ship's pitching angular acceleration, 、 、 is the additional moment of inertia, 、 、 are the forces and moments acting on the ship, with subscript represents the inertial hydrodynamic force and moment.

[0049] Assuming the ship is sailing straight ahead at a constant speed, =0, =0, the inertial hydrodynamic force and moment of the bare hull are calculated as follows:

[0050] Ship heave additional mass and pitch additional moment of inertia It can be calculated according to the following formula:

[0051] Where, C w is the waterplane coefficient, C p is the prismatic coefficient, is the ratio of ship's breadth to draft, is the waterplane coefficient, is the prismatic coefficient, is the waterline length of the ship, For the quality of the ship.

[0052] With speed 、 It can be calculated by the following formula:

[0053]

[0054] Where, is the ship speed, is the encounter frequency, 、 are the heave damping coefficient and additional mass coefficient of the cross-section, 、 Cross-sections representing the bow and stern of a ship.

[0055] The expressions of viscous hydrodynamic forces and moments in the pitch and heave directions are as follows:

[0056] Where, is the heave velocity, is the pitch angle; is the pitch angular velocity, is the pitch angular acceleration, is the heave acceleration, and each term in the formula is solved by the following formula:

[0057]

[0058] Where, 、 are the damping coefficient and additional mass coefficient of the cross-section, is the ratio of the amplitude at infinity to the amplitude of the column's heaving motion, C is the dimensionless hydrodynamic mass at the slice section, B is the section width, 、 Representing the bow and stern cross-sections, HL represents the viscous hydrodynamic forces and moments.

[0059] The sum of the bare hull hydrodynamic forces and moments for all hulls is calculated as:

[0060] Since the propellers are arranged symmetrically on the left and right, the propeller force and torque have an effect on the forward, sway and bow motions, but have little effect on the pitch and heave of the ship in waves and can be ignored, so the propeller force and torque are both 0.

[0061] For hulls connected by hinges, the force transmission of the hinges needs to be considered. Hinges allow the transmission of force but not the transmission of torque.

[0062] Figure 6 is a schematic diagram of the spatial rectangular coordinate system of the hinge provided in the embodiment of the present application, such as Figure 6 As shown, the hinge i transfers the force to the next square ship i+1, and then decomposes it on the square ship i+1 to obtain the vertical force on the square ship i+1. The hinge only transfers the vertical force and longitudinal force to the square ship, and does not transfer the pitching moment, so the moment of the hinge is 0.

[0063] Since the hinge transmits force and the moment constraint is free, the vertical force on the hinge is the resultant of the vertical forces on the upper hull, then:

[0064]

[0065] The mathematical model of the heave and pitch motion of the tandem combined ship in regular waves can be obtained:

[0066] In some embodiments, the calculation process of the sum of the wave forces of all hulls and the sum of the wave moments of all hulls includes: Calculate the radiation force, diffraction force and incident waves of a monohull; Based on the radiation force, diffraction force and incident wave of the monohull, the sum of the wave forces on all hulls and the sum of the wave moments on all hulls are calculated.

[0067] First calculate the radiation force of the monohull When a ship is heaving and pitching with the waves, the velocity potential in the flow field can be obtained by superimposing three velocity potentials, among which the radiation potential caused by the ship's own motion around it is , radiation potential The pressure change caused by , the pressure is integrated along the boundary of the cross section to obtain the fluid force acting on the cross section. U The radiation force on the slices of a sailing ship It can be expressed as:

[0068] Then calculate the diffraction force , the diffraction potential caused by the reflection of the waves by the hull , diffraction potential The pressure change caused by , the pressure is integrated along the boundary of the cross section to obtain the fluid force acting on the cross section. U The diffraction force on the slice of a sailing ship It can be expressed as:

[0069] Where, is the wave frequency, is the damping coefficient of the corresponding slice, is the additional mass of the slice, is the vertical motion acceleration of the ship's cross section.

[0070] Then calculate the incident wave , incident potential The pressure change caused by , the pressure is integrated along the boundary of the cross section to obtain the fluid force acting on the cross section. U The incident wave on the slice of a sailing ship is It can be expressed as:

[0071] in, is the amplitude of the incident wave, i.e. the height of the wave, is the incident angle of the wave, that is, the angle between the wave propagation direction and the ship's sailing direction, is the waterline width of the corresponding cross section.

[0072] By integrating the three forces on each slice along the length of the ship, we can obtain the fluid force generated by the heaving of the hull when the ship is performing heaving and pitching motion:

[0073] Similarly, in the heave and pitch motion, the pitch angle when the bow tilts is is a positive value. Therefore, at this time, by integrating along the length of the ship, we can obtain the hydrodynamic moment on the hull:

[0074] in, is the longitudinal coordinate of the ship coordinate system. The negative sign represents that when the hull tilts forward, the moment generated is negative.

[0075] The wave forces of all hulls are synthesized to obtain the sum of the wave forces acting on the entire series combined ship:

[0076] The wave moments of all hulls are synthesized to obtain the sum of the wave moments of the entire series-connected ship:

[0077] In some embodiments, step 120 specifically includes: Step 1201, pre-processing the motion history data; The obtained ship heave and pitch motion history data are cleaned and normalized to remove noise and standardize the data.

[0078] Step 1202, extracting feature data from the pre-processed motion history data; Feature data that helps with prediction is extracted from the historical data of the ship's heave and pitch motion. The feature data may include heave value, pitch angle, etc.

[0079] Step 1203, constructing the feature data into a time series format suitable for the LSTM prediction model; Step 1204 , using the feature data in a time series format suitable for the LSTM prediction model, train the LSTM prediction model.

[0080] Optionally, feature data in a time series format suitable for the LSTM prediction model is used to optimize the LSTM prediction model network parameters through an error back propagation algorithm.

[0081] In some embodiments, step 110 specifically includes: The fourth-order Runge-Kutta integral is used to solve the mathematical model of motion and obtain the historical data of heave and pitch motion of the series-connected ships.

[0082] The principle of the fourth-order Runge-Kutta integration is to transform the dynamic equation into a system of first-order differential equations, such as using = and = As an intermediate variable. Apply the Runge-Kutta integral formula for time stepping:

[0083] Double counting 、 、 .

[0084] Update variables:

[0085] in, represents the function on the right side of the differential equation, is the time step, subscript Indicates the current step, Indicates the next step.

[0086] In some embodiments, the method further comprises: Evaluate the trained LSTM prediction model.

[0087] The accuracy and reliability of the prediction model are evaluated by comparing it with the actual measurement data.

[0088] Figure 7 is a schematic diagram of a user interaction interface provided by an embodiment of the present application, such as Figure 7 As shown, in one embodiment of the present application, a user interaction interface is designed to enhance user experience and make the system easier to use and more efficient, including: 1. Parameter input: Provides users with an interactive input interface, allowing users to enter or modify the physical parameters of the ship, such as hull size, mass, moment of inertia, etc.

[0089] 2. Wave condition setting: The design interface allows users to set wave characteristics, including wave height, period, wavelength and wave direction.

[0090] 3. Simulation control: including starting, pausing, stopping and resetting the simulation process.

[0091] 4. Result display: Graphically display the simulation results, including the time history of heave value and pitch angle, as well as corresponding charts and animations.

[0092] 5. Data import and export: allows users to import historical data for model training, or export simulation results for further analysis.

[0093] 6. Model configuration: Users can configure the parameters of the LSTM model, such as network structure, number of training iterations, etc.

[0094] 7. Help and documentation: Provide help information, instructions and system documentation to facilitate users to learn and use the system.

[0095] Figure 8 FIG. 1 is a structural diagram of a device for predicting the heave and pitch motion of a series-connected ship in regular waves provided by an embodiment of the present application. Figure 8 As shown, the system includes a building module 810, a solving module 820, a training module 830 and an acquisition module 840, wherein: Establishing module 810, for establishing a mathematical model of heaving and pitching motion of the series-connected combination ship in regular waves, the heaving and pitching motion mathematical model is used to describe the physical characteristics and motion laws of the series-connected combination ship; A solving module 820 is used to solve the motion mathematical model to obtain the heave and pitch motion history data of the series-connected ships; A training module 830 is used to train an LSTM prediction model based on motion history data; The acquisition module 840 is used to input the real-time heave and pitch motion data of the series-connected ship into the trained LSTM prediction model, and obtain the heave and pitch motion data of the next moment output by the trained LSTM prediction model.

[0096] Based on the method in the above embodiment, Figure 9 An example of a physical structure diagram of an electronic device is shown below. Figure 9 As shown, an embodiment of the present application provides an electronic device, which may include: a processor 910, a communication interface 920, a memory 930, and a communication bus 940, wherein the processor 910, the communication interface 920, and the memory 930 communicate with each other via the communication bus 940. The processor 910 can call the logic instructions in the memory 930 to execute the simulation method for predicting the heave and pitch motion of a series-connected ship in regular waves in the above embodiment.

[0097] Furthermore, the logic instructions in the aforementioned memory 930 can be implemented in the form of software functional units and, when sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the portion that contributes to the prior art, or the portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method for predicting and simulating the heave and pitch motion of a series-connected ship in regular waves, as described in various embodiments of the present application.

[0098] Based on the method in the above embodiment, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the simulation method for predicting the heave and pitch motion of a series-connected ship in regular waves in the above embodiment.

[0099] Based on the method in the above embodiment, an embodiment of the present application provides a computer program product. When the computer program product runs on a processor, the processor executes the simulation method for predicting the heave and pitch motion of a series-connected ship in regular waves in the above embodiment.

[0100] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0101] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC.

[0102] The above embodiments can be implemented in whole or in part through software, hardware, firmware, or any combination thereof. When implemented using software, they can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, the computer program instructions fully or partially produce the processes or functions described in the embodiments of this application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted via the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer, or a data storage device such as a server or data center that integrates one or more available media. The available medium can be magnetic media (e.g., floppy disk, hard disk, tape), optical media (e.g., DVD), or semiconductor media (e.g., solid-state drive (SSD)).

[0103] It will be understood that the various numerical numbers involved in the embodiments of the present application are merely distinctions for the convenience of description and are not intended to limit the scope of the embodiments of the present application.

[0104] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for predicting the heave and pitch motion of a series-connected ship in regular waves, characterized in that: include: Establishing a mathematical model of heaving and pitching motions of a tandem combination ship in regular waves, wherein the mathematical model of heaving and pitching motions is used to describe the physical characteristics and motion laws of the tandem combination ship; Solving the motion mathematical model to obtain historical data of heave and pitch motion of the series-connected ships; Based on the movement history data, a long short-term memory network (LSTM) prediction model is trained; The real-time heaving and pitching motion data of the series-connected ship are input into the trained LSTM prediction model to obtain the heaving and pitching motion data of the next moment output by the trained LSTM prediction model.

2. The method for predicting and simulating the heave and pitch motion of a tandem-connected ship in regular waves according to claim 1, characterized in that: The method of establishing a mathematical model of heave and pitch motion of a series-connected ship in regular waves includes: Establish a mathematical model of the serial combined ship coordinate system and the heave and pitch motion of a single hull in regular waves; Based on the serially combined ship coordinate system, calculating the sum of the bare hull hydrodynamic forces of all hulls, the sum of the bare hull moments of all hulls, the sum of the propeller forces of all hulls, the sum of the propeller moments of all hulls, the sum of the wave forces of all hulls, the sum of the wave moments of all hulls, and the forces and moments of the hinges; Based on the mathematical model of the heaving and pitching motion of the single hull in regular waves, the sum of the bare hull hydrodynamics of all hulls, the sum of the bare hull moments of all hulls, the sum of the propeller forces of all hulls, the sum of the propeller moments of all hulls, the sum of the wave forces of all hulls, the sum of the wave moments of all hulls, and the forces and moments of the hinges, a mathematical model of the heaving and pitching motion of the series combination ship in regular waves is established.

3. The method for predicting and simulating the heave and pitch motion of a tandem-connected ship in regular waves according to claim 2 is characterized in that: The calculation process of the sum of the wave forces of all hulls and the sum of the wave moments of all hulls includes: Calculate the radiation force, diffraction force and incident waves of a monohull; Based on the radiation force, diffraction force and incident wave of the monohull, the sum of the wave forces of all the hulls and the sum of the wave moments of all the hulls are calculated.

4. The method for predicting and simulating the heave and pitch motion of a tandem-connected ship in regular waves according to claim 1, characterized in that: The training of the LSTM prediction model based on the motion history data includes: Preprocessing the motion history data; Extracting feature data from preprocessed motion history data; Constructing the feature data into a time series format suitable for the LSTM prediction model; Use feature data in a time series format suitable for the LSTM forecasting model to train the LSTM forecasting model.

5. The method for predicting and simulating the heave and pitch motion of a tandem-connected ship in regular waves according to claim 1, characterized in that: The step of solving the motion mathematical model to obtain the heave and pitch motion history data of the series-connected ship comprises: The motion mathematical model is solved using a fourth-order Runge-Kutta integral to obtain the heave and pitch motion history data of the series-connected ships.

6. The method for predicting and simulating the heave and pitch motion of a tandem-connected ship in regular waves according to claim 1, characterized in that: The method further comprises: The trained LSTM prediction model is evaluated.

7. A device for predicting and simulating the heave and pitch motion of a series-connected ship in regular waves, characterized in that: include: An establishment module is used to establish a mathematical model of the heave and pitch motion of the series-connected ship in regular waves, wherein the mathematical model of the heave and pitch motion is used to describe the physical characteristics and motion laws of the series-connected ship; A solving module, used for solving the motion mathematical model to obtain the heave and pitch motion history data of the series-connected ship; A training module, configured to train an LSTM prediction model based on the motion history data; The acquisition module is used to input the real-time heaving and pitching motion data of the series-connected ship into the trained LSTM prediction model, and obtain the heaving and pitching motion data of the next moment output by the trained LSTM prediction model.

8. An electronic device, characterized in that: include: at least one memory for storing a computer program; At least one processor is used to execute the program stored in the memory. When the program stored in the memory is executed, the processor is used to execute the simulation method for predicting the heave and pitch motion of a series-connected ship in regular waves as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is run on a processor, the processor is caused to execute the method for simulating the prediction of the heave and pitch motion of a series-connected ship in regular waves according to any one of claims 1 to 6.

10. A computer program product, characterized in that When the computer program product is run on a processor, the processor is caused to execute the method for simulating the prediction of the heave and pitch motion of a series-connected ship in regular waves according to any one of claims 1 to 6.

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