Construction ship operation parameter optimization method and system based on wind wave coupling

Abstract

The application discloses a construction ship operation parameter optimization method and system based on wind wave coupling, and belongs to the technical field of construction ships, comprising a multi-body dynamics model and a multi-body dynamics equation, wherein the multi-body dynamics model comprises a rigid body model constructed based on ship body and hoisted object parameters, an elastic body model constructed based on hoisting rope parameters, and a nonlinear spring model constructed based on mooring system parameters; the multi-body dynamics equation comprises a translation analysis module and a rotation analysis module based on the rigid body model; a tension analysis module based on the elastic body model and a nonlinear deformation analysis module based on the nonlinear spring model; an environmental load calculation module, which firstly calculates the force of environmental load on the construction ship, and then takes the calculation result as the input of the multi-body dynamics model; a motion response solving module, which solves the motion response of the multi-body dynamics model through a numerical integration method; and a mooring force calculation module, which calculates the tension distribution of each cable based on the motion response and the nonlinear characteristics of the mooring system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of construction ships, and particularly relates to a construction ship operation parameter optimization method and system based on wind wave coupling. BACKGROUND

[0002] Construction ships, also known as floating cranes, are special vessels designed for handling large cargoes in ports. These ships are equipped with advanced lifting equipment, and their crane booms are designed in fixed or rotating types to meet different operational requirements. The lifting capacity of construction ships usually ranges from hundreds to thousands of tons, enabling them to handle various large cargoes. It is worth noting that construction ships generally do not have self-propulsion capabilities, so they usually need the assistance of other tugboats for movement. In addition to cargo handling, construction ships are often used as port engineering ships to participate in various port construction and maintenance work.

[0003] When performing lifting and towing operations of construction ships, these ships are inevitably affected by various complex environmental factors such as wind, waves, and currents. These environmental factors jointly act on the construction ship, making its motion response and mooring force distribution extremely complex and variable. These factors have a direct impact on the safety and efficiency of the operation. Currently, to predict the behavior of construction ships during lifting and towing operations, traditional single-degree-of-freedom models or simplified multi-degree-of-freedom models are mainly relied on. However, due to the simplified nature of these models, they often fail to accurately reflect the multi-body dynamics behavior of construction ships in actual operations. Especially in lifting operations, the complex interaction between the lifted object and the ship body is often ignored, which leads to a large deviation between the predicted results and the actual working conditions. This deviation not only affects the safety of the operation, but also reduces the efficiency of the operation, so developing more accurate models and prediction techniques is crucial for improving the safety and efficiency of construction ship operations. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art and provides a construction ship operation parameter optimization method and system based on wind wave coupling, which can accurately predict the motion response and mooring force distribution of construction ships in complex sea conditions, especially considering the interaction between the lifted object and the ship body, providing a more accurate scientific basis for the design and operation of construction ships.

[0005] To achieve the above-mentioned application purposes, the first purpose of the present application is to provide a construction ship operation parameter optimization system based on wind wave coupling, which comprises:

[0006] A multi-body dynamics model comprising a rigid body model constructed based on hull and cargo parameters, an elastic body model constructed based on sling parameters, and a nonlinear spring model constructed based on mooring system parameters; and a multi-body dynamics equation comprising a translation analysis module based on the rigid body model, a rotation analysis module based on the rigid body model, a tension analysis module based on the elastic body model, and a nonlinear deformation analysis module based on the nonlinear spring model;

[0007] An environmental load calculation module that first calculates the force of environmental loads on the construction vessel and then uses the calculation results as input to the multi-body dynamics model;

[0008] A motion response solving module that solves the motion response of the multi-body dynamics model by a numerical integration method, the motion response comprising six degrees of freedom motion of the hull and the cargo and tension changes of the slings;

[0009] A mooring force calculation module that calculates the tension distribution of each cable based on the motion response and the nonlinear characteristics of the mooring system.

[0010] Preferably, in the translation analysis module, the translation equation is:

[0011] ;

[0012] wherein, M is a rigid body mass matrix; r is a rigid body mass center position; F evn is an environmental load; F couple is a coupling force of the slings and the mooring system; F moor is a mooring system tension; t is time;

[0013] In the rotation analysis module, the rotation equation is:

[0014] ;

[0015] wherein, I is a rigid body inertia tensor; ω is an angular velocity; T evn is an environmental moment; T couple is a sling moment; T moor is a mooring moment.

[0016] Preferably, in the tension analysis module, the expression of each tension is:

[0017] ;

[0018] wherein, T ( s ) is a tension distribution; h( s,t ) is a positions and time t of displacement; f evn is the resultant external force, including gravity and fluid resistance; p d is the line density of the hanger rope.

[0019] Preferably, in the non-linear deformation analysis module, the non-linear relationship between the mooring rope tension and the elongation is:

[0020] ;

[0021] ;

[0022] wherein, F moor，i is the mooring rope tension of the nth i rope, Δ L i is the elongation of the nth i rope; k i (Δ L i ) is the non-linear stiffness coefficient; c i is the damping coefficient; m i is the ship body connection point position; n i is the seabed anchor point position; L 0,i is the original length of the rope when not subjected to external force, is the norm of the vector .

[0023] Preferably, the environmental load includes wave load, wind load and flow load; wherein:

[0024] The calculation formula of the wave load is:

[0025] ;

[0026] wherein ，F wave is the wave load, p w is the seawater density; C D is the resistance coefficient; C M is the inertia coefficient; D is the characteristic diameter of the ship body; L is the immersed length; u is the horizontal velocity of the water quality point;

[0027] The calculation formula of the wind load is:

[0028] ;

[0029] wherein ，F wind is the wind load, p a is the air density; C wind is the shape dependent wind drag coefficient; A proj is the wetted surface area of the hull, V wind is the wind velocity;

[0030] The formula for the flow load is:

[0031] ;

[0032] wherein ，F current is the flow load, C current is the flow drag coefficient; A wet is the wetted surface area of the hull, V current is the flow velocity.

[0033] Preferably, in the motion response solving module, the multi-body dynamics equations are converted into a first order ordinary differential equation system, defining a state vector y = [r, v, θ, ω] T The first order ordinary differential equation system is:

[0034] ;

[0035] r is the xyz directional position vector; v is the xyz directional linear velocity vector; θ is the angle of rotation around the xyz axes; ω is the xyz directional angular velocity vector;

[0036] Time discretization is performed using the fourth order Runge-Kutta method:

[0037] The slope is calculated:

[0038] ;

[0039] The state is updated:

[0040] ;

[0041] wherein, k 1 is the slope of the previous time point; k 2 is the t n + hslope of / 2, using k 1's delta prediction; k 3 is at the same intermediate time point t n + h improved slope of / 2, using k 2's delta prediction; k 4 is at the next time point t n + h slope of / 2, using k 3's delta prediction; h is the time step, h <2 / ω max ; ω max is the system maximum frequency; y n is the current state; t n is the current time;

[0042] Rigid body constraint handling is then performed: Euler angles or quaternions are used to avoid singularities; the rotation matrix is orthogonally normalized after state update and the elastic body coupling: the displacement and velocity boundary conditions of the discrete segments of the tethers are updated synchronously with the rigid body connection points.

[0043] Preferably, the mooring force calculation module comprises:

[0044] calculating geometric relations defining the first i root cable hull connection point position m i and the seabed anchor point position n i , the instantaneous length of the cable L i (t) is:

[0045] ;

[0046] where m i ( t ) is the instantaneous position coordinate of the hull connection point i; L i ( t ) is the length of the first i root cable line;

[0047] the elongation is:

[0048] ;

[0049] where Δ L i is the elongation of the first i root cable; is the first iInitial length of the root cable; For the i Current length of the root cable;

[0050] Extension rate:

[0051] ;

[0052] Where, v i ( t ) is the instantaneous linear velocity of the connection point i ;

[0053] Calculate the nonlinear tension, substitute into the nonlinear stiffness model:

[0054] ;

[0055] Where, is the nonlinear tension at time t experienced by the i root cable;

[0056] The nonlinear stiffness is:

[0057] ;

[0058] Where, Δ L yield is the cable yield extension; Δ L i is the extension of the i root cable; k 1,i is the initial linear stiffness of the i root cable at time t; k 2 , i is the initial linear stiffness of the i root cable at time t;

[0059] Dynamic correction, the relationship between cable inertia effect and fluid resistance is:

[0060] ;

[0061] represents the total force experienced by the i root cable;

[0062] represents the nonlinear tension experienced by the i root cable;

[0063] represents the drag coefficient of the cable;

[0064] D represents the cable diameter;

[0065] v rel =v i t i -V current , v rel represents the difference between the tangential velocity of the cable and the flow velocity;

[0066] is the unit vector of the cable direction;

[0067] The cable stress amplitude is:

[0068] Δσ i = F i / A c ;

[0069] wherein, A c is the cross-sectional area of the cable; Δσ i is the stress amplitude of the nth cable; i

[0070] The fatigue life of the cable is:

[0071]

[0072] wherein, is the fatigue life of the nth cable; i C and s are material constants, and the damage is accumulated by the Miner rule.

[0073] Preferably, the data visualization and optimization module is further included to visualize the calculation results of the motion response and the mooring force, to display the predicted motion trajectory of the ship body and the hoisted object, the change of the hoisting rope tension, and the force distribution of the mooring cable through a graphical interface, and to optimize the mooring scheme and the operation strategy of the construction ship.

[0074] ​​Preferably, the data visualization and optimization module is configured to realize motion visualization verification and optimization by setting up a six-degree-of-freedom non-contact motion measurement system, which is composed of multiple motion capture cameras and acquisition and analysis software. The motion capture cameras complete the task of motion capture by monitoring and tracking specific marker points on the measured object. In order to facilitate processing, some specially designed markers, called "Marker", are usually required to be attached to the key parts of the object. These markers have the functions of reflecting light or actively emitting light. The infrared camera emits invisible infrared light to the marker, which reflects the infrared light, which is captured again by the camera. Thus, the accurate spatial position of the marker point is recorded. The visual system will identify and process these markers. After the system is calibrated, the camera continuously captures the motion of the measured object and saves the image sequence, which is then analyzed and processed to identify the marker points. When the motion capture camera continuously captures at a high enough rate, the data acquisition and analysis software can obtain the motion trajectory and six-degree-of-freedom data of the point from the image sequence. The six-degree-of-freedom motion response data is compared with the motion curve drawn according to the multi-body theory simulation system data to verify the accuracy of the multi-body prediction system data and complete the system optimization work.

[0075] A second object of the present application is to provide a construction vessel operation parameter optimization method based on wind wave coupling, comprising:

[0076] S1, a multi-body dynamics model and a multi-body dynamics equation of the construction vessel are established, the multi-body dynamics model comprises a rigid body model constructed based on hull and hoisted object parameters, an elastic body model constructed based on hoisting rope parameters, and a nonlinear spring model constructed based on mooring system parameters; the multi-body dynamics equation comprises a translation analysis module and a rotation analysis module based on the rigid body model, a tension analysis module based on the elastic body model, and a nonlinear deformation analysis module based on the nonlinear spring model;

[0077] S2, environmental load calculation, first calculate the force of the environmental load on the construction vessel, and then take the calculation result as the input of the multi-body dynamics model;

[0078] S3, the motion response of the multi-body dynamics model is solved by a numerical integration method, the motion response comprises six-degree-of-freedom motion of the hull and the hoisted object and tension change of the hoisting rope;

[0079] S4, the force condition of the mooring system is calculated, and the tension distribution of each cable is calculated based on the motion response and the nonlinear characteristics of the mooring system;

[0080] S5, the data accuracy of the multi-body simulation prediction system is verified by setting up a six-degree-of-freedom non-contact motion measurement system, and optimization suggestions are proposed;

[0081] S6, display the motion response and the calculation result of the mooring force through a graphical interface, and provide a prediction result.

[0082] The application has the advantages and positive effects that:

[0083] The application can accurately predict, verify and optimize the motion response and the distribution of the mooring force of the construction ship under complex sea conditions. Specifically:

[0084] 1. Improve the prediction accuracy:

[0085] The application optimizes the calculation variables of the whole process of the unified motion system by using the multi-body dynamics model and accurately modeling the nonlinear mooring system, and verifies the accuracy of the motion response data of the above multi-body simulation prediction system through the setting of the six-degree-of-freedom non-contact motion measurement system, feeds back to the multi-body theory simulation system to complete the optimization, which can more accurately predict the motion response and the distribution of the mooring force of the construction ship under various complex sea conditions. In particular, the application considers the interaction between the hoisted object and the ship body, which significantly improves the prediction accuracy and provides more reliable data support for the design and operation of the construction ship.

[0086] 2. Optimize the mooring scheme:

[0087] The application integrates data visualization technology and optimization modules, and through these advanced tools, designers can more intuitively analyze and evaluate the mooring scheme of the construction ship. This not only helps to optimize the operation strategy and ensure the safety of the operation process, but also improves the efficiency of the operation, making the operation of the construction ship more accurate and efficient.

[0088] 3. Reduce the test cost:

[0089] The application adopts numerical simulation method, which can replace a large number of physical model tests. In this way, the test cost can be significantly reduced, and the design cycle can be shortened. This not only saves valuable time and resources for the design and construction of the construction ship, but also makes the entire design process more economical and efficient. BRIEF DESCRIPTION OF DRAWINGS

[0090] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0091] Figure 1 It is a front view of the multi-body dynamics model in the embodiments of the application.

[0092] Figure 2A mooring top view for a multi-body dynamics model in an embodiment of the present application;

[0093] Figure 3 An environmental load calculation flowchart in an embodiment of the present application;

[0094] Figure 4 A motion response solving flowchart in an embodiment of the present application;

[0095] Figure 5 A mooring force calculation flowchart in an embodiment of the present application;

[0096] Figure 6 A total calculation flowchart in an embodiment of the present application;

[0097] Figure 7 A six-degree-of-freedom non-contact motion measurement system arrangement in an embodiment of the present application;

[0098] Figure 8 A data visualization and optimization interface schematic in an embodiment of the present application. DETAILED DESCRIPTION

[0099] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0100] Please refer to Figures 1 to 8 ,

[0101] A first embodiment is a construction vessel operation parameter optimization system based on wind wave coupling, comprising:

[0102] A multi-body dynamics model and a multi-body dynamics equation, the multi-body dynamics model comprising a rigid body model constructed based on hull and hoist parameters, an elastic body model constructed based on hoist rope parameters, and a nonlinear spring model constructed based on mooring system parameters; the multi-body dynamics equation comprising a translation analysis module and a rotation analysis module based on the rigid body model, a tension analysis module based on the elastic body model, and a nonlinear deformation analysis module based on the nonlinear spring model;

[0103] In this embodiment, the hull 1, the boom 2, and the hoist 3 are modeled as rigid bodies, the hoist rope 4 is modeled as an elastic body, and the mooring system is modeled as a nonlinear spring system. Through the multi-body dynamics equation, the interaction between the hull, the hoist, and the hoist rope is described, especially the influence of the hoist on the hull motion.

[0104] The multi-body dynamics equation is as follows:

[0105] Rigid body motion equation (ship body and sling load)

[0106] The core of the translation analysis module is the translation equation, the expression of which is:

[0107]

[0108] where, M is the rigid body mass matrix; r is the position of the center of mass of the rigid body; F env is the environmental load (wind, wave, current); F couple is the coupling force of the sling and mooring system; F moor is the mooring system tension; t is the time.

[0109] The core of the rotation analysis module is the rotation equation, the expression of which is:

[0110]

[0111] where, I is the rigid body inertia tensor; ω is the angular velocity; T env is the environmental moment; T couple is the sling moment; T moor is the mooring moment.

[0112] Sling dynamics equation (elastic body)

[0113] The sling is modeled as an elastic body model, and the tension analysis module uses a piecewise discrete method, and each piece of tension satisfies:

[0114]

[0115] where, T s is the tension distribution, which is related to the strain , is the strain, EA is the tensile stiffness; h( s, t ) is the displacement of the sling at position s and time t ; f env is the resultant external force, including gravity and fluid resistance; p d is the linear density of the sling.

[0116] Boundary conditions: the two ends of the sling are connected to the ship body and the sling load respectively, and must satisfy the displacement compatibility requirement.

[0117] ​The core of the nonlinear deformation analysis module is the mooring system equation (nonlinear spring), and the nonlinear relationship between the mooring cable tension and elongation is as follows:

[0118]

[0119] ;

[0120] in, F moor，i For the first i The mooring cable tension of the root cable, Δ L i For the first i The elongation of the cable; k i (Δ L i ) represents the nonlinear stiffness coefficient; c i m is the damping coefficient; i The location of the hull connection point; n i This indicates the location of the seabed anchor point; L 0,i The original length of the cable when it is not subjected to external force. For vectors The norm of .

[0121] The environmental load calculation module first calculates the forces exerted by the environmental load on the construction vessel, and then uses the calculation results as input for the multibody dynamics model.

[0122] Please see Figure 3 The environmental load calculation module aims to assess the impact of environmental factors such as wind, waves, and currents on construction vessels. Environmental loads include wave loads, wind loads, and current loads; wave loads are calculated based on potential flow theory, wind loads are calculated using empirical formulas, and current loads are calculated through fluid dynamics simulations. The calculated environmental load data will serve as input parameters for the multibody dynamics model. Environmental loads encompass wave forces, wind forces, and current forces, which are calculated separately and then superimposed.

[0123] Wave force (potential flow theory) uses the Morison equation to calculate wave loads:

[0124] ;

[0125] in ，F wave For wave loads, p w The density of seawater; C D The drag coefficient is approximately 0.7-1.2. C Mis the inertia coefficient (about 1.5-2.0); D is the hull characteristic diameter, L is the submerged length; u is the water quality point horizontal velocity.

[0126] The expression of the wind load is:

[0127] ;

[0128] where ，F wind is the wind load, p a =1.225 kg / m 3 (Air density); C wind is the shape-dependent wind drag coefficient (about 0.8-1.2 for the hull); A proj is the windward projected area of the hull; V wind is the wind speed;

[0129] The expression of the flow load (simplified formula for CFD simulation) is:

[0130]

[0131] where ，F current is the flow load, C current is the flow drag coefficient (about 0.1-0.3); A wet is the wet surface area of the hull; V current is the flow speed.

[0132] The motion response solving module solves the motion response of the multi-body dynamics model by a numerical integration method, the motion response including six-degree-of-freedom motion of the hull and the suspended object and tension change of the sling;

[0133] Please refer to Figure 4 , the motion response solving module converts the multi-body dynamics equation into a first-order ordinary differential equation (ODE): define the state vector y=[r,v,θ,ω] T , the first-order ordinary differential equation is:

[0134]

[0135] r is xyz a directional position vector; v is xyz a directional linear velocity vector; θ is an angle of rotation around the xyz axis; and ω is xyz a directional angular velocity vector.

[0136] The fourth-order Runge-Kutta method (RK4) is used for time discretization:

[0137] The slope is calculated:

[0138]

[0139] The state is updated:

[0140]

[0141] where, k 1 is the slope at the previous time point; k 2 is the slope at the intermediate time point t n + h / 2 using the incremental prediction of k 1; k 3 is the improved slope at the same intermediate time point t n + h / 2 using the incremental prediction of k 2; k 4 is the slope at the next time point t n + h using the incremental prediction of k 3; h is the time step, h <2 / ω max ; ω max is the highest frequency of the system; y n is the current state; t n is the current time.

[0142] After that, rigid body constraints are handled: Euler angles or quaternions are used to avoid singularities; the rotation matrix is orthogonally normalized after updating the state, and the elastic body coupling: the displacement and velocity boundary conditions of the rigid body connection points of the discrete segments of the sling are updated synchronously.

[0143] The motion response solving module aims to solve the motion response problem in the multi-body dynamics model. This module uses numerical integration techniques (such as the Runge-Kutta method) to analyze the multi-body dynamics equations, thereby obtaining the motion response data of the construction ship in complex sea conditions. These data cover the six degrees of freedom motion of the ship body and the suspended objects— including lateral movement, longitudinal movement, vertical lifting, lateral swing, longitudinal inclination, and rotational motion— as well as the tension changes of the slings.

[0144] The mooring force calculation module calculates the tension distribution of each cable based on the motion response and the nonlinear characteristics of the mooring system. The mooring force calculation module aims to evaluate the force condition of the mooring system. By considering the motion response of the ship and the nonlinear characteristics of the mooring system, this module can calculate the tension distribution of each mooring cable, especially for the maximum tension of the mooring cable and its fatigue life.

[0145] Please refer to Figure 5 , the mooring force calculation process is as follows:

[0146] The mooring force calculation module calculates the tension distribution of each cable based on the motion response and the nonlinear characteristics of the mooring system. The mooring force calculation module aims to evaluate the force condition of the mooring system. By considering the motion response of the ship and the nonlinear characteristics of the mooring system, this module can calculate the tension distribution of each mooring cable, especially for the maximum tension of the mooring cable and its fatigue life. r b , speed v b ) and the nonlinear characteristics of the mooring system;

[0147] Step 1: Geometric relationship calculation, assuming that the first i root cable connects the ship point position m i and the seabed anchor point position n i , the instantaneous length L i (t) of this cable is:

[0148]

[0149] m i ( t ) is the instantaneous position coordinate of the ship connection point; i L i t ) is the length of the first cable line of the ship; i

[0150] The elongation is:

[0151]

[0152] Δ L i is the elongation of the first cable; i is the initial length of the first cable; is the present length of the first cable. The elongation rate is: i i

[0153]

[0154] where, v i t ) is the instantaneous linear velocity of the connection point (derived from the ship motion); i ​​​​​​​​

[0155] Step 2: Nonlinear tension calculation, substitute nonlinear stiffness model:

[0156]

[0157] where, is the nonlinear tension of the i-th cable at time t; i

[0158] Nonlinear stiffness example:

[0159]

[0160] where, Δ L yield is the cable yield elongation; Δ L i is the elongation of the i-th cable; i k 1,i is the initial linear stiffness of the i-th cable i at time t; k 2 , i is the initial linear stiffness of the i-th cable i at time t.

[0161] Step 3: Dynamic correction, considering cable inertia effect and fluid resistance:

[0162]

[0163] is the total force on the i-th cable; i

[0164] is the nonlinear tension of the i-th cable; i is the drag coefficient of the cable;

[0165] is the cable diameter;

[0166] D

[0167] v rel =v i t i -V current , v rel is the difference between the cable tangential velocity and the flow velocity;

[0168] ​​​​​​is the unit vector of the cable direction;

[0169] Step 4: the cable stress amplitude is

[0170] Δσ i = F i / A c

[0171] wherein, A c is the cross-sectional area of the cable; Δσ i is the stress amplitude of the nth cable. i

[0172] The fatigue life of the cable is

[0173]

[0174] wherein, is the fatigue life of the nth cable; i C and s are material constants, and the damage is accumulated by the Miner rule.

[0175] A six-degree-of-freedom non-contact motion measurement system is set up to realize motion visualization verification and optimization, which is composed of multiple motion capture cameras and data acquisition and analysis software. The motion capture camera completes the task of motion capture by monitoring and tracking specific marker points on the measured object. In order to facilitate processing, some specially designed marker balls, called "Marker", are usually required to be attached to the key parts of the object. These markers have the functions of reflecting light or actively emitting light. The infrared camera emits invisible infrared light to the marker, which reflects the infrared light, and the camera captures it again. In this way, the accurate spatial position of the marker point is recorded. The visual system will identify and process these markers. After the system is calibrated, the camera continuously shoots the motion of the measured object and saves the image sequence, and then analyzes and processes it to identify the marker points. When the motion capture camera continuously shoots at a high enough rate, the data acquisition and analysis software can obtain the motion trajectory and six-degree-of-freedom data of the point from the image sequence. By comparing the data results of the multi-body theory prediction system and the visual measurement system, the accuracy of the method can be verified and optimized.

[0176] Data visualization and optimization module, please refer to Figure 7 ​​, 3D dynamic model view displays the trajectory of the vessel / hoisting object movement. The real-time attitude indicator is used to show the 6-DOF motion attitude of the current object. The mooring force distribution radar chart displays the tension of the root cable, including the tension of cable 1 (red bar), the tension of cable 2 (gray bar), the tension of cable 3 (orange bar), and the tension of cable 4 (green bar). The time series curve includes three charts, which respectively show the changes of the construction vessel roll, pitch and heave with time. The optimization suggestion panel suggests adjusting the cable pretension and recommends the operation window period. The alarm indication area marks the areas that need special attention for structural safety. This module aims to graphically display the calculation results of the motion response and the mooring force, and provide corresponding optimization suggestions. Through the graphical interface, the motion trajectory of the vessel and the hoisting object, the change of the sling tension, the force distribution of the mooring cable, and other information are displayed to assist the designer in optimizing the mooring scheme and operation strategy of the construction vessel.

[0177] In a second embodiment, a construction vessel operation parameter optimization method based on wind wave coupling is provided, comprising:

[0178] S1, a multi-body dynamics model and a multi-body dynamics equation of the construction vessel are established, the multi-body dynamics model includes a rigid body model constructed based on the parameters of the vessel and the hoisting object, an elastic body model constructed based on the parameters of the sling, and a nonlinear spring model constructed based on the parameters of the mooring system; the multi-body dynamics equation includes a translation analysis module and a rotation analysis module based on the rigid body model, a tension analysis module based on the elastic body model, and a nonlinear deformation analysis module based on the nonlinear spring model;

[0179] In this embodiment, the multi-body dynamics model is constructed according to the actual size and operation condition of the construction vessel. The vessel and the hoisting object are modeled as rigid bodies, the sling is modeled as an elastic body, and the mooring system is modeled as a nonlinear spring system.

[0180] S2, the environmental load is calculated, the force of the environmental load on the construction vessel is calculated first, and then the calculation result is taken as the input of the multi-body dynamics model;

[0181] S3, the motion response of the multi-body dynamics model is solved by a numerical integration method, the motion response includes the 6-DOF motion of the vessel and the hoisting object and the tension change of the sling;

[0182] S4, the force condition of the mooring system is calculated, the tension distribution of each cable is calculated based on the motion response and the nonlinear characteristics of the mooring system;

[0183] S5, the data accuracy of the multi-body simulation prediction system is verified by setting a 6-DOF non-contact motion measurement system, and optimization suggestions are proposed;

[0184] S6, display the calculation results of the motion response and the mooring force through a graphical interface, and provide prediction results.

[0185] The present application first applies the multi-body dynamics theory to the prediction of the lifting and towing motion response of the construction ship, which is an innovative method that particularly considers the interaction between the lifted object and the ship body. Compared with traditional single-degree-of-freedom or simplified multi-degree-of-freedom models, the present application can more accurately reflect the complex dynamics behavior of the construction ship in actual operation, thereby providing more accurate theoretical support for engineering design and operation.

[0186] In the present application, a nonlinear spring system is used to simulate the force characteristics of the mooring cable, which can more realistically reflect the tension changes of the mooring cable under actual working conditions. In particular, for the prediction of the maximum tension and fatigue life of the mooring cable, the present application provides more accurate calculation results, which is of great significance to ensure the safety and reliability of the mooring system of the construction ship.

[0187] The present application adopts a combination of potential flow theory, empirical formula and fluid dynamics simulation to accurately calculate the effects of environmental loads such as wind, wave and current on the construction ship. Through this comprehensive calculation method, the accuracy of the motion response prediction can be ensured, providing a scientific basis for the design and operation of the construction ship.

[0188] In order to make the user more intuitively understand the calculation results of the motion response and the mooring force, the present application displays these data through a graphical interface. In addition, the present application also provides optimization suggestions to help designers optimize the mooring scheme and operation strategy of the construction ship, thereby improving the safety and efficiency of the operation and ensuring the smooth progress of the lifting operation.

[0189] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When all or part of the embodiments are implemented in the form of a computer program product, the computer program product includes one or more computer instructions. When the computer program instructions are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable systems. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through a wired (such as coaxial cable, optical fiber, digital subscriber line (DSL) or wireless (such as infrared, wireless, microwave, etc.)) way. 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, data center, etc. integrated with one or more available media sets. The available media can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (SSD)) and the like.

[0190] The above description is only the preferred embodiment of the present application, and it should be pointed out that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A system for optimizing the operational parameters of construction vessels based on wind-wave coupling, characterized in that, include: The multibody dynamics model and multibody dynamics equations are provided. The multibody dynamics model includes a rigid body model based on the parameters of the hull and the suspended object, an elastic body model based on the parameters of the hoisting rope, and a nonlinear spring model based on the parameters of the mooring system. The multibody dynamics equations include a translational analysis module and a rotational analysis module based on the rigid body model. Tension analysis module based on elastic body model and nonlinear deformation analysis module based on nonlinear spring model; The environmental load calculation module first calculates the forces exerted by the environmental load on the construction vessel, and then uses the calculation results as input for the multibody dynamics model. The motion response solution module solves the motion response of the multibody dynamics model through numerical integration. The motion response includes the six degrees of freedom motion of the hull and the suspended load, as well as the tension change of the suspension rope. The mooring force calculation module calculates the tension distribution of each cable based on motion response and the nonlinear characteristics of the mooring system.

2. The construction vessel operation parameter optimization system based on wind-wave coupling as described in claim 1, characterized in that, In the translational analysis module, the translational equation is: ； in, M Let the mass matrix be the rigid body mass matrix. r The location of the center of mass of the rigid body; F evn For environmental load; F couple For the coupling force between the hoisting rope and the mooring system; F moor For the mooring system pull; t For time; In the rotation analysis module, the rotation equation is: ； in, I For rigid body inertia tensor; ω T is the angular velocity; evn For environmental torque; T couple T is the torque of the hoisting rope. moor This is the mooring torque.

3. The construction vessel operation parameter optimization system based on wind-wave coupling as described in claim 2, characterized in that, In the tension analysis module, the expression for each tension segment is: ； in, T ( s ) represents the tension distribution; h( s,t (This refers to the position of the suspension rope) s and time t displacement; f evn The resultant force of external forces, including gravity and fluid resistance; ρ d This refers to the linear density of the suspension rope.

4. The construction vessel operation parameter optimization system based on wind-wave coupling as described in claim 3, characterized in that, In the nonlinear deformation analysis module, the nonlinear relationship between mooring cable tension and elongation is as follows: ； ； in, F moor，i For the first i The mooring cable tension of the root cable, Δ L i For the first i The elongation of the cable; k i (Δ L i ) represents the nonlinear stiffness coefficient; c i m is the damping coefficient; i The location of the hull connection point; n i This indicates the location of the seabed anchor point; L 0,i This is the original length of the cable when it is not subjected to external force. For vectors The norm of .

5. The construction vessel operation parameter optimization system based on wind-wave coupling as described in claim 4, characterized in that, The environmental loads include wave loads, wind loads, and flow loads; wherein: The formula for calculating wave load is: ； in ，F wave For wave loads, ρ w The density of seawater; C D This is the drag coefficient; C M The inertia coefficient; D The characteristic diameter of the hull; L The length of the water immersion; u The horizontal velocity of the water particles; The formula for calculating wind load is: ； in ，F wind For wind load, ρ a air density; C wind Shape-dependent drag coefficient; A proj The windward projected area of ​​the ship's hull; V wind Wind speed; The formula for calculating flow load is: ； in ，F current For flow load, C current The flow resistance coefficient; A wet This represents the wetted surface area of ​​the ship's hull. V current is the flow velocity.

6. The construction vessel operation parameter optimization system based on wind-wave coupling as described in claim 5, characterized in that, In the motion response solution module, the multibody dynamics equations are transformed into a system of first-order ordinary differential equations, and the state vector is defined. y =[r,v,θ,ω] T The system of first-order ordinary differential equations is as follows: ； r is xyz Direction and position vector; v is xyz Directional linear velocity vector; θ is the angle of rotation about the xyz axis; ω is... xyz Direction angular velocity vector; Time discretization is performed using the fourth-order Runge-Kutta method: Calculate the slope: ； Update status: ； in, k 1 represents the slope at the previous time point; k 2 is the intermediate time point. t n + h The slope of / 2, using k Incremental prediction of 1; k 3 is at the same intermediate time point t n + h / 2 improved slope, using k Incremental prediction of 2; k 4 represents the next time point. t n + h The slope, using k Incremental prediction of 3; h For time step, h <2 / ω max ; ω max This is the highest frequency of the system. y n This is the current state; t n The current time; Then, rigid body constraints are applied: Euler angles or quaternions are used to avoid singularities; after updating the state, the orthogonal normalized rotation matrix and elastic body coupling are implemented: the displacement and velocity boundary conditions of the discrete segments of the suspension rope and the connection points of the rigid body are updated synchronously.

7. The construction vessel operation parameter optimization system based on wind-wave coupling as described in claim 6, characterized in that, The mooring force calculation module includes: Computational geometric relations, defining the first i Location of the cable connection point on the hull (m) i and the location of the seabed anchor point n i The instantaneous length of the cable L i (t) is: ； Where, m i ( t () represents the instantaneous position coordinates of the hull connection point i; L i ( t ) is the hull number i Length of the cable line; Elongation is: ； Where, Δ L i For the first i The elongation of the cable; For the first i The initial length of the cable; For the first i The current length of the cable; Elongation rate: ； in, v i ( t ) is the connection point i The instantaneous linear velocity; Calculate the nonlinear tension and substitute it into the nonlinear stiffness model: ； in, To indicate the first i The nonlinear tension experienced by the cable at time t; The nonlinear stiffness is: ； Where, Δ L yield Δ is the yield elongation of the cable. L i For the first i The elongation of the cable; k 1,i For the first i root cable Initial linear stiffness; k 2 , i For the first i root cable Initial linear stiffness; Dynamic correction: The relationship between cable inertia and fluid resistance is as follows: ； Indicates the first i The total force acting on the cable; Indicates the first i The nonlinear tension experienced by the cable; Indicates the resistance coefficient of the cable; D Indicates the diameter of the cable; v rel =v i t i -V current , v rel This represents the difference between the tangential velocity of the cable and the flow velocity. The unit vector representing the direction of the cable; The cable stress amplitude is: Board i = F i / A c ; in, A c Δσ is the cross-sectional area of ​​the cable. i To indicate the first i The stress amplitude of the cable; The fatigue life of the cable is: in, Indicates the first i The fatigue life of the cable; C and s is a material constant, and the damage is accumulated using the Miner criterion.

8. The construction vessel operation parameter optimization system based on wind-wave coupling according to any one of claims 1-7, characterized in that: It also includes a data visualization and optimization module, which visualizes the calculation results of motion response and mooring force, and displays the predicted motion trajectory of the hull and the hoisted object, the change of hoisting rope tension, and the force distribution of mooring cables through a graphical interface, so as to optimize the mooring scheme and operation strategy of the construction vessel.

9. The construction vessel operation parameter optimization system based on wind-wave coupling as described in claim 8, characterized in that: The data visualization and optimization module sets up a six-degree-of-freedom non-contact motion measurement system to realize motion visualization verification and optimization. It consists of multiple motion capture lenses and acquisition and analysis software. The motion capture lenses complete the motion capture task by monitoring and tracking the markers on the measured object.

10. A method for optimizing the operational parameters of construction vessels based on wind-wave coupling, characterized in that, include: S1. Establish the multibody dynamics model and multibody dynamics equations of the construction vessel. The multibody dynamics model includes a rigid body model constructed based on the parameters of the hull and the hoisted object, an elastic body model constructed based on the parameters of the hoisting rope, and a nonlinear spring model constructed based on the parameters of the mooring system. The multibody dynamics equations include translational and rotational analysis modules based on the rigid body model, tension analysis modules based on the elastic body model, and nonlinear deformation analysis modules based on the nonlinear spring model. S2. Environmental load calculation: First, calculate the force of the environmental load on the construction vessel, and then use the calculation results as input for the multibody dynamics model. S3. Solve the motion response of the multibody dynamics model by numerical integration method. The motion response includes the six degrees of freedom motion of the hull and the suspended object, as well as the tension change of the suspension rope. S4. Calculate the force conditions of the mooring system. Based on the motion response and nonlinear characteristics of the mooring system, calculate the tension distribution of each cable. S5. Verify the data accuracy of the multibody simulation prediction system by setting up a six-degree-of-freedom non-contact motion measurement system, and propose optimization suggestions; S6. Display the calculation results of motion response and mooring force through a graphical interface, and provide prediction results.

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