Construction ship operation parameter optimization method and system based on storm coupling effect

Abstract

The invention discloses a construction ship operation parameter optimization method and system based on the wind wave coupling effect, and belongs to the technical field of construction ships. The multi-body dynamic model comprises a rigid body model constructed based on parameters of a ship body and a hanging object, an elastomer model constructed based on parameters of a hanging rope and a nonlinear spring model constructed based on parameters of a mooring system; the multi-body kinetic equation comprises a translation analysis module and a rotation analysis module based on a rigid body model; the tension analysis module is based on an elastomer model; the nonlinear deformation analysis module is based on a nonlinear spring model; the environment load calculation module is used for firstly calculating the acting force of the environment load on the workboat, and then taking the calculation result as the input of the multi-body dynamic model; the motion response solving module solves the motion response of the multi-body dynamic model through a numerical integration method; the mooring force calculation module calculates tension distribution of each cable based on the motion response and nonlinear characteristics of the mooring system.

Description

Technical Field

[0001] The present invention belongs to the technical field of construction vessels, and particularly relates to an optimization method and system for the operation parameters of construction vessels based on the coupled action of wind and waves. Background Art

[0002] A construction vessel, also known as a floating crane, is a special vessel designed specifically for loading and unloading large goods at ports. This type of vessel is equipped with advanced lifting equipment, and its boom design is divided into two types: fixed and rotary, to adapt to different operation requirements. The lifting capacity of construction vessels usually ranges from several hundred tons to several thousand tons, and can handle various large goods. It should be noted that construction vessels generally do not have the ability of self-navigation, so they usually need the assistance of other tugboats to move. In addition to loading and unloading goods, construction vessels are often used as port engineering vessels to participate in various port construction and maintenance work.

[0003] When performing the hoisting and towing operations of construction vessels, these vessels will inevitably be affected by various complex environmental factors such as wind, waves, and water currents. The combined action of these environmental factors on construction vessels makes the distribution of their motion responses and mooring forces extremely complex and variable. These factors have a direct impact on the safety and efficiency of the operation. Currently, in order to predict the behavior of construction vessels during hoisting and towing operations, it mainly relies on traditional single-degree-of-freedom models or simplified multi-degree-of-freedom models. However, due to the simplified nature of these models, they are often difficult to accurately reflect the multi-body dynamics behavior of construction vessels in actual operations. Especially during hoisting operations, the complex interaction between the suspended object and the hull is often ignored, resulting in a large deviation between the prediction results and the actual working conditions. This deviation not only affects the safety of the operation but also reduces the efficiency of the operation. Therefore, developing more accurate models and prediction technologies is crucial for improving the safety and efficiency of construction vessel operations. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides an optimization method and system for the operation parameters of construction vessels based on the coupled action of wind and waves, which can accurately predict the motion response and the distribution of mooring forces of construction vessels under complex sea conditions, especially considering the interaction between the suspended object and the hull, and provides a more accurate scientific basis for the design and operation of construction vessels.

[0005] To achieve the above invention objective, the first objective of the present invention is to provide an optimization system for the operation parameters of construction vessels based on the coupled action of wind and waves, including: Multi-body dynamics model and multi-body dynamics equations. The multi-body dynamics model includes a rigid body model constructed based on hull and suspended object parameters, an elastic body model constructed based on suspension rope parameters, and a non-linear spring model constructed based on mooring system parameters; the multi-body dynamics equations include a translational analysis module and a rotational analysis module based on the rigid body model; a tension analysis module based on the elastic body model and a non-linear deformation analysis module based on the non-linear spring model. An environmental load calculation module, which first calculates the force exerted by environmental loads on the construction vessel, and then uses 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 by numerical integration. The motion response includes the six-degree-of-freedom motion of the hull and the suspended object and the tension change of the suspension rope. A mooring force calculation module, which calculates the tension distribution of each cable based on the motion response and the non-linear characteristics of the mooring system.

[0006] Preferably, in the translational analysis module, the translational equation is: ; Where M is the rigid body mass matrix; r is the position of the rigid body centroid; F evn is the environmental load; F couple is the coupling force of the suspension rope and the mooring system; F moor is the mooring system tension; t is the time; In the rotational analysis module, the rotational equation is: ; Where I is the rigid body inertia tensor; ω is the angular velocity; T evn is the environmental torque; T couple is the suspension rope torque; T moor is the mooring torque.

[0007] Preferably, in the tension analysis module, the expression of each segment of tension is: ; Where T ( s ) is the tension distribution; h( s, t ) is the displacement of the suspension rope at position s and time t ; f evn is the resultant of external forces, including gravity and fluid resistance; ρ d is the linear density of the suspension rope.

[0008] Preferably, in the non-linear deformation analysis module, the non-linear relationship between the mooring cable tension and the elongation is: ; ; where F moor，i is the mooring cable tension of the i th cable, and Δ L i is the elongation of the i th cable; k i (Δ L i ) is the non-linear stiffness coefficient; c i is the damping coefficient; m i is the position of the hull connection point; n i is the position of the seabed anchor point; L 0,i is the original length of the cable when not subjected to external force, is the norm of the vector .

[0009] Preferably, the environmental loads include wave loads, wind loads, and current loads; where: The calculation formula for wave loads is: ; where ，F wave is the wave load, ρ w is the seawater density; C D is the drag coefficient; C M is the inertia coefficient; D is the characteristic diameter of the hull; L is the immersed length; u is the horizontal velocity of the water particle; The calculation formula for wind loads is: ; where ，F wind is the wind load, ρ a is the air density; C wind is the shape-related wind resistance coefficient; A proj is the windward projected area of the hull; V wind is the wind speed; The calculation formula for current loads is: ; Wherein ，F current is the flow load, C current is the flow resistance coefficient; A wet is the wetted surface area of the hull, V current is the flow velocity.

[0010] Preferably, in the motion response solving module, the multi-body dynamics equation is converted into a system of first-order ordinary differential equations, and the state vector y =[r,v,θ,ω] T is defined, and the system of first-order ordinary differential equations is: ; r is the x, y, z direction position vector; v is the x, y, z direction linear velocity vector; θ is the angle of rotation about the xyz axis; ω is the x, y, z direction angular velocity vector; The fourth-order Runge-Kutta method is used for time discretization: Calculate the slope: ; Update the state: ; Wherein, k 1 is the slope at the previous time point; k 2 is the slope at the intermediate time point t n + h / 2, predicted using the increment of ‌k 1; k 3 is the improved slope at the same intermediate time point t n + h / 2, predicted using the increment of ‌k 2; ‌k 4 is the slope at the next time point t n + h predicted using the increment 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; Subsequently, rigid body constraint processing is performed: Euler angles or quaternions are used to avoid singularities; after updating the state, the rotation matrix is orthonormalized, and for elastomer coupling: the displacement and velocity boundary conditions of the discrete segments of the suspension ropes and the connection points of the rigid bodies are updated synchronously.

[0011] Preferably, the mooring force calculation module includes: Calculate the geometric relationship and define the position m of the connection point of the i ith cable to the hull i and the position n of the seabed anchor point i . The instantaneous length L i l(t) of this cable is: ; where m i ( t ) is the instantaneous position coordinate of the connection point i of the hull; L i l t ( i ) is the length of the ith cable of the hull; The elongation is: ; where Δ L i l i is the elongation of the ith cable; l i 0 is the initial length of the ith cable; i l is the current length of the ith cable; ; where v i v t ( i ) is the instantaneous linear velocity of the connection point Calculate the nonlinear tension and substitute it into the nonlinear stiffness model: ; where T i is the nonlinear tension of the ith cable at time t; The nonlinear stiffness is: ; where Δ L yield l L i l i is the elongation of the ith cable; k 1,i ki The root cable Initial linear stiffness at time k 2 , i is the i root cable Initial linear stiffness at time Dynamic correction, the relationship between the cable inertia effect and the fluid resistance is: ; represents the total force on the i root cable; represents the non - linear tension on the i root cable; represents the drag coefficient of the cable; D represents the cable diameter; v rel =v i t i -V current , v rel represents the difference between the tangential velocity of the cable and the flow velocity; is the unit vector in the cable direction; The stress amplitude of the cable is: Δσ i = F i / A c ; where, A c is the cross - sectional area of the cable; Δσ i represents the stress amplitude of the i root cable; The fatigue life of the cable is:

[0012] where, represents the fatigue life of the i root cable; C and s are material constants, and cumulative damage is calculated by the Miner criterion.

[0013] Preferably, it further includes a data visualization and optimization module, which visually displays the calculation results of the motion response and the mooring force, and displays the predicted motion trajectories of the hull and the suspended object, the changes in the sling tension, and the force distribution of the mooring cables through a graphical interface, so as to optimize the mooring plan and operation strategy of the construction ship.

[0014] Preferably, 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 cameras and acquisition and analysis software. The motion capture cameras complete the motion capture task by monitoring and tracking specific landmark points on the object to be measured. For easy processing, it is usually required to attach some special marker balls to the key parts of the object, called "Markers". These Markers have the functions of reflecting light or emitting light actively. The infrared camera emits invisible infrared light and irradiates it on the marker, and the marker will reflect the infrared light, which is captured by the camera again, so that the accurate spatial position of the marker point is recorded. The vision system will identify and process these markers. After the system is calibrated, the camera continuously shoots the actions of the object to be measured and saves the image sequence, and then analyzes and processes it to identify the marker points. When the motion capture cameras continuously shoot at a high enough rate, the data acquisition and analysis software can obtain the motion trajectory and six-degree-of-freedom data of this point from the image sequence. Compare the motion curves drawn according to the obtained six-degree-of-freedom motion response data and the data of the multi-body theory simulation system to verify the accuracy of the multi-body prediction system data and complete the system optimization work.

[0015] The second object of the present invention is to provide a method for optimizing the operation parameters of a construction ship based on the coupled action of wind and waves, including: S1. Establish a multi-body dynamics model and multi-body dynamics equations of the construction ship. The multi-body dynamics model includes a rigid body model constructed based on the hull and suspended object parameters, an elastic body model constructed based on the sling parameters, and a nonlinear spring model constructed based on the mooring system parameters; the multi-body dynamics equations include a translational analysis module and a rotational 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. S2. Calculate the environmental load. First, calculate the force exerted by the environmental load on the construction ship, and then use the calculation result as the input of the multi-body dynamics model. S3. Solve the motion response of the multi-body dynamics model by numerical integration methods. The motion response includes the six-degree-of-freedom motion of the hull and the suspended object and the change in the tension of the sling. S4. Calculate the force condition of the mooring system, and calculate the tension distribution of each cable based on the motion response and the nonlinear characteristics of the mooring system. S5. Verify the data accuracy of the multi-body 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 responses and mooring forces through a graphical interface, and provide prediction results.

[0016] The advantages and positive effects of this application are as follows: The present invention can accurately predict, verify, and optimize the motion responses of a construction vessel and the distribution of mooring forces under complex sea conditions. Specifically: 1. Improve prediction accuracy: By applying a multi-body dynamics model and accurately modeling the non-linear mooring system, the present invention optimizes the calculation variables throughout the unified motion system. By setting up a six-degree-of-freedom non-contact motion measurement system to verify the accuracy of the motion response data of the above multi-body simulation prediction system and feeding back to the multi-body theoretical simulation system for optimization, it can more accurately predict the motion responses and mooring force distributions of the construction vessel under various complex sea conditions. In particular, the present invention takes into account the interaction between the suspended object and the hull, and this careful consideration significantly improves the prediction accuracy, providing more reliable data support for the design and operation of the construction vessel.

[0017] 2. Optimize the mooring plan: The present invention integrates data visualization technology and an optimization module. Through these advanced tools, designers can more intuitively analyze and evaluate the mooring plan of the construction vessel. This not only helps to optimize the operation strategy and ensure the safety of the operation process, but also improves the operation efficiency, making the operation of the construction vessel more accurate and efficient.

[0018] 3. Reduce test costs: The present invention uses numerical simulation methods, and the application of this technology can replace a large number of physical model tests. In this way, it can significantly reduce test costs and shorten the design cycle. This not only saves valuable time and resources for the design and construction of the construction vessel, but also makes the entire design process more economical and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. Figure 1 The front view of the multi-body dynamics model in the embodiment of the present invention; Figure 2 The mooring top view of the multi-body dynamics model in the embodiment of the present invention; Figure 3 It is the flowchart of environmental load calculation in the embodiment of the present invention; Figure 4 It is the flowchart of motion response solution in the embodiment of the present invention; Figure 5 It is the flowchart of mooring force calculation in the embodiment of the present invention; Figure 6 It is the overall calculation flowchart in the embodiment of the present invention; Figure 7 It is the layout diagram of the six-degree-of-freedom non-contact motion measurement system in the embodiment of the present invention; Figure 8 It is the schematic diagram of the data visualization and optimization interface in the embodiment of the present invention. Specific implementation manners

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Please refer to Figures 1 to 8 , The first embodiment, an operation parameter optimization system for a construction ship based on the coupling action of wind and waves, includes: A multi-body dynamics model and multi-body dynamics equations. The multi-body dynamics model includes a rigid body model constructed based on the hull and load parameters, an elastic body model constructed based on the sling parameters, and a non-linear spring model constructed based on the mooring system parameters; the multi-body dynamics equations include a translational analysis module and a rotational analysis module based on the rigid body model, a tension analysis module based on the elastic body model, and a non-linear deformation analysis module based on the non-linear spring model. In this embodiment, the hull 1, the boom 2, and the load 3 are respectively modeled as rigid bodies, the sling 4 is modeled as an elastic body, and the mooring system is modeled as a non-linear spring system. Through the multi-body dynamics equations, the interactions between the hull, the load, and the sling are described, especially the influence of the load on the hull motion.

[0022] The multi-body dynamics equations are as follows: Rigid body motion equations (hull and load) The core of the translational analysis module is the translational equation, and the expression of the translational equation is:

[0023] Wherein, M is the rigid body mass matrix; r is the position of the rigid body centroid; Fenv is the environmental load (wind, wave, current); F couple is the coupling force of the suspension rope and the mooring system; F moor is the mooring system tension; t is time.

[0024] The core of the rotation analysis module is the rotation equation, and the expression of the rotation equation is:

[0025] where, I is the rigid body inertia tensor; ω is the angular velocity; T env is the environmental torque; T couple is the suspension rope torque; T moor is the mooring torque.

[0026] Suspension rope dynamics equation (elastic body) The suspension rope is modeled as an elastic body model, and the tension analysis module adopts a segmented discrete method. The tension of each segment satisfies:

[0027] where, T ( s ) is the tension distribution, related to the strain ( , is the strain, EA is the tensile stiffness); h( s, t ) is the displacement of the suspension rope at position s and time t ; f env is the resultant external force, including gravity and fluid resistance; ρ d is the linear density of the suspension rope.

[0028] Boundary condition: The two ends of the suspension rope are connected to the hull and the suspended load respectively, and the displacement coordination requirement must be satisfied.

[0029] The core of the non-linear deformation analysis module is the mooring system equation (non-linear spring). The non-linear relationship between the mooring cable tension and the elongation is:

[0030] ; where, F moor，i is the mooring cable tension of the i th mooring cable, Δ L i is the elongation of the i th mooring cable; k i (Δ Li ) is the non-linear stiffness coefficient; c i is the damping coefficient; m i is the position of the hull connection point; n i is the position of the seabed anchor point; L 0,i The original length of the cable when not subjected to external force, is the vector norm of.

[0031] The environmental load calculation module first calculates the force exerted by the environmental load on the construction ship, and then uses the calculation result as the input of the multi-body dynamics model; Please refer to Figure 3 , the environmental load calculation module aims to evaluate the influence of environmental factors such as wind, waves, and currents on the construction ship. Environmental loads include wave loads, wind loads, and current loads; among them, the calculation of wave loads is based on potential flow theory, the calculation of wind loads is based on empirical formulas, and the calculation of current loads is achieved through hydrodynamic simulation. The calculated environmental load data will be used as the input parameters of the multi-body dynamics model. Environmental loads cover wave forces, wind forces, and current forces, and are comprehensively superimposed after separate calculations.

[0032] Wave force (potential flow theory) uses the Morison equation to calculate wave loads: ; Where ，F wave is the wave load, ρ w is the seawater density; C D is the drag coefficient (about 0.7 - 1.2); C M is the inertia coefficient (about 1.5 - 2.0); D is the hull characteristic diameter, L is the immersed length; u is the horizontal velocity of the water particle.

[0033] The expression of wind load is: ; Where ，F wind is the wind load, ρ a = 1.225 kg / m 3 (air density); C wind is the shape-related wind resistance coefficient (about 0.8 - 1.2 for the hull); A proj is the windward projected area of the hull; Vwind is the wind speed; The expression of the flow load (simplified formula for CFD simulation) is:

[0034] where ，F current is the flow load, C current is the flow resistance coefficient (about 0.1 - 0.3); A wet is the wetted surface area of the hull; V current is the flow velocity.

[0035] The motion response solving module solves the motion response of the multi - body dynamics model through numerical integration methods. The motion response includes the six - degree - of - freedom motion of the hull and the suspended object and the tension change of the suspension rope; Please refer to Figure 4 , the motion response solving module converts the multi - body dynamics equation into a system of first - order ordinary differential equations (ODE): Define the state vector y = [r, v, θ, ω] T , the system of first - order ordinary differential equations is:

[0036] r is the x, y, z direction position vector; v is the x, y, z direction linear velocity vector; θ is the angle of rotation about the xyz axes; ω is the x, y, z direction angular velocity vector.

[0037] Time discretization is carried out using the fourth - order Runge - Kutta method (RK4): Calculate the slope:

[0038] Update the state:

[0039] 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, predicted using the increment of ‌k 1; k 3 is the improved slope at the same intermediate time point t n + h / 2, predicted using the increment of ‌k 2; ‌k 4 is the slope at the next time point tn + h‌ The slope of, using ‌k Increment prediction of 3; h is the time step, h <2 / ω max ; ω max is the system's highest frequency; y n is the current state; t n is the current time.

[0040] After that, rigid body constraint processing is carried out: Use Euler angles or quaternions to avoid singularities; Orthonormalize the rotation matrix after updating the state and elastomer coupling: Synchronously update the displacement and velocity boundary conditions at the connection points between the discrete segments of the suspension ropes and the rigid body.

[0041] 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, and then obtains the motion response data of the construction ship under complex sea conditions. These data cover the six-degree-of-freedom motion of the hull and the suspended items - including lateral movement, longitudinal movement, vertical lifting, lateral swaying, longitudinal tilting, and rotational motion - as well as the tension changes in the suspension ropes.

[0042] The mooring force calculation module calculates the tension distribution of each cable based on the motion response and the non-linear characteristics of the mooring system. The mooring force calculation module aims to evaluate the force condition of the mooring system. By considering the hull motion response and the non-linear characteristics of the mooring system, this module can calculate the tension distribution of each mooring cable, especially accurately evaluate the maximum tension of the mooring cable and its fatigue life.

[0043] Please refer to Figure 5 , the mooring force calculation process is as follows: The mooring force calculation module calculates the tension distribution of each cable based on the hull motion response (displacement r b , velocity v b ) and the non-linear characteristics of the mooring system; Step 1: Geometric relationship calculation, assuming the position m i of the connection point between the i th cable and the hull and the position n i of the seabed anchor point, the instantaneous length L i (t) of this cable is:

[0044] m i ( t) is the instantaneous position coordinate of the hull connection point i ; L i ( t ) is the length of the i th cable of the hull; The elongation is:

[0045] Δ L i is the elongation of the i th cable; is the initial length of the i th cable; is the current length of the i th cable. The elongation rate is:

[0046] Among them, v i ( t ) is the instantaneous linear velocity of the connection point i (derived from the hull movement); Step 2: Nonlinear tension calculation, substituting into the nonlinear stiffness model:

[0047] Among them, represents the nonlinear tension of the i th cable at time t; Nonlinear stiffness example:

[0048] Among them, Δ L yield is the yield elongation of the cable; Δ L i is the elongation of the i th cable; k 1,i is the initial linear stiffness of the i th cable at; k 2 , i is the initial linear stiffness of the i th cable at.

[0049] Step 3: Dynamic correction, considering the cable inertia effect and fluid resistance:

[0050] represents the total force on the i th cable; Indicates the i nonlinear tension on the nth cable; Indicates the resistance coefficient of the cable; D Indicates the cable diameter; v rel =v i t i -V current , v rel Indicates the difference between the tangential velocity of the cable and the flow velocity; Is the unit vector in the cable direction; Step 4: The cable stress amplitude is: Δσ i = F i / A c Where, A c Is the cross-sectional area of the cable; Δσ i Indicates the i stress amplitude of the nth cable.

[0051] The fatigue life of the cable is:

[0052] Where, Indicates the i fatigue life of the nth cable; C and s Are material constants, and cumulative damage is calculated by the Miner criterion.

[0053] Set up a six - degree - of - freedom non - contact motion measurement system to achieve motion visualization verification and optimization. It consists of multiple motion capture cameras and acquisition and analysis software, etc. The motion capture cameras complete the task of motion capture by monitoring and tracking specific landmark points on the object to be measured. For easy processing, it is usually required to attach some special marker balls, called "Markers", 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 and irradiates it on the marker. The marker will reflect the infrared light, and the camera captures it again, thus recording the accurate spatial position of the marker point. The vision system will identify and process these markers. After the system is calibrated, the camera continuously shoots the actions of the object to be measured and saves the image sequence, and then analyzes and processes it to identify the marker points. When the motion capture camera shoots continuously at a high enough rate, the data acquisition and analysis software can obtain the motion trajectory and six - degree - of - freedom data of this point from the image sequence. By comparing the data results of the multi - body theory prediction system and the visualization measurement system, the accuracy of this method can be verified and optimized.

[0054] For the data visualization and optimization module, please refer to Figure 7 , the 3D dynamic model view shows the motion trajectory lines of the hull / lifted object, indicating the trajectory of the hull or lifted object. The real - time attitude indicator is used to display the six - degree - of - freedom motion attitude of the current object. The mooring force distribution radar chart shows the tension of the root cables, namely 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, respectively showing the changes of the roll, pitch, and heave of the construction hull over time. The optimization suggestion panel suggests adjusting the cable pretension and recommending the operation window period. The alarm indication area marks the areas that require special attention for structural safety. This module aims to graphically display the calculation results of the motion response and mooring force and provide corresponding optimization suggestions. Through the graphical interface, it shows information such as the motion trajectory of the hull and the lifted load, the variation of the sling tension, and the force distribution of the mooring cables, to assist designers in optimizing the mooring plan and operation strategy of the construction ship.

[0055] The second embodiment, a method for optimizing the operation parameters of a construction ship based on the coupled action of wind and waves, includes: S1. Establish a multi - body dynamics model and multi - body dynamics equations of the construction ship. The multi - body dynamics model includes a rigid - body model constructed based on the hull and lifted - object parameters, an elastic - body model constructed based on the sling parameters, and a non - linear spring model constructed based on the mooring - system parameters. The multi - body dynamics equations include a translational analysis module and a rotational analysis module based on the rigid - body model, a tension analysis module based on the elastic - body model, and a non - linear deformation analysis module based on the non - linear spring model; In this embodiment, a multi-body dynamics model is constructed based on the actual dimensions and operating conditions of the construction vessel. Among them, the hull and the suspended load are modeled as rigid bodies, the suspension cable is modeled as an elastic body, and the mooring system is modeled as a non-linear spring system.

[0056] S2. Calculate the environmental loads. First, calculate the forces exerted by the environmental loads on the construction vessel, and then use the calculation results as the input to the multi-body dynamics model. S3. Solve the motion responses of the multi-body dynamics model through numerical integration methods. The motion responses include the six-degree-of-freedom motions of the hull and the suspended object, as well as the tension changes of the suspension ropes. S4. Calculate the forces on the mooring system. Based on the motion responses and the non-linear characteristics of the mooring system, calculate the tension distributions of each cable. S5. Verify the data accuracy of the multi-body simulation prediction system by setting up a six-degree-of-freedom non-contact motion measurement system, and put forward optimization suggestions. S6. Display the calculation results of the motion responses and the mooring forces through a graphical interface, and provide prediction results.

[0057] The present invention applies the multi-body dynamics theory to the prediction of the motion responses of the construction vessel during hoisting and towing for the first time. This innovative method particularly considers the interaction between the suspended object and the hull. Compared with the traditional single-degree-of-freedom or simplified multi-degree-of-freedom models, the present invention can more accurately reflect the complex dynamic behaviors of the construction vessel during actual operations, thereby providing more precise theoretical support for engineering design and operation.

[0058] In the present invention, a non-linear spring system is used to simulate the force characteristics of the mooring cables. This method can more realistically reflect the tension changes of the mooring cables under actual working conditions. Especially for the prediction of the maximum tension and fatigue life of the mooring cables, the present invention provides more accurate calculation results, which is of great significance for ensuring the safety and reliability of the mooring system of the construction vessel.

[0059] The present invention adopts a method combining potential flow theory, empirical formulas and hydrodynamic simulations to accurately calculate the actions of environmental loads such as wind, waves and currents on the construction vessel. 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 vessel.

[0060] In order to enable users to more intuitively understand the calculation results of the motion responses and the mooring forces, the present invention displays these data through a graphical interface. In addition, the present invention also provides optimization suggestions to help designers optimize the mooring plan and operation strategy of the construction vessel, thereby improving the safety and efficiency of the operation and ensuring the smooth progress of the lifting operation.

[0061] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When 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 the computer program instructions are loaded or executed on a computer, the processes or functions described in the embodiments of the present invention are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable systems. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more integrated available media. The available medium may be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid-state disk (SSD)).

[0062] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An operation parameter optimization system for construction ships based on the coupled action of wind and waves, characterized in that Comprising: A multi-body dynamics model and multi-body dynamics equations. The multi-body dynamics model includes a rigid body model constructed based on hull and suspended object parameters, an elastic body model constructed based on sling parameters, and a non-linear spring model constructed based on mooring system parameters; the multi-body dynamics equations include a translational analysis module and a rotational analysis module based on the rigid body model; A tension analysis module based on the elastic body model and a non-linear deformation analysis module based on the non-linear spring model; An environmental load calculation module, which first calculates the acting force of the environmental load on the construction ship, and then uses 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 by means of numerical integration. The motion response includes the six-degree-of-freedom motion of the hull and the suspended object and the tension change of the sling; A mooring force calculation module, which calculates the tension distribution of each cable based on the motion response and the non-linear characteristics of the mooring system.

2. The construction ship operation parameter optimization system based on the coupling action of wind and waves according to claim 1, wherein In the translational analysis module, the translational equation is: ； Among them, M is the rigid body mass matrix; r is the position of the rigid body's center of mass; F evn is the environmental load; F couple is the coupling force of the suspension rope and the mooring system; F moor is the mooring system tension; t is the time; In the rotational analysis module, the rotational equation is: ； Among them, I is the rigid body inertia tensor; ω is the angular velocity; T evn is the environmental torque; T couple is the suspension rope torque; T moor is the mooring torque.

3. The construction ship operation parameter optimization system based on the coupled action of wind and waves according to claim 2, characterized in that, In the tension analysis module, the expression of the tension of each section is: ； Among them, T ( s ) is the tension distribution; h( s,t ) is the displacement of the suspension rope at position s and time t ; f evn is the resultant external force, including gravity and fluid resistance; ρ d is the linear density of the suspension rope.

4. The construction ship operation parameter optimization system based on the coupling action of wind and waves according to claim 3, characterized in that, In the non-linear deformation analysis module, the non-linear relationship between the mooring cable tension and the elongation is: ； ； Among them, F moor，i is the mooring cable tension of the i th cable, and Δ L i is the elongation of the i th cable; k i (Δ L i ) is the non - linear stiffness coefficient; c i is the damping coefficient; m i is the position of the hull connection point; n i is the position of the seabed anchor point; L 0,i is the original length of the cable when no external force is applied, is the norm of the vector .

5. The construction ship operation parameter optimization system based on the coupling action of wind and waves according to claim 4, characterized in that, The environmental load includes wave load, wind load and current load; among them: The calculation formula of the wave load is: ； Among them ，F wave is the wave load, ρ w is the seawater density; C D is the drag coefficient; C M is the inertia coefficient; D is the characteristic diameter of the hull; L is the immersed length; u is the horizontal velocity of the water particle; The calculation formula of the wind load is: ； Among them ，F wind is the wind load, ρ a is the air density; C wind is the shape-related wind resistance coefficient; A proj is the windward projected area of the hull; V wind is the wind speed; The calculation formula of the current load is: ； Among them ，F current is the flow load, C current is the flow resistance coefficient; A wet is the wetted surface area of the hull, V current is the flow velocity.

6. The construction ship operation parameter optimization system based on the coupling action of wind and waves according to claim 5, wherein In the motion response solving module, the multi-body dynamics equations are converted into a system of first-order ordinary differential equations, and the state vector y = [r, v, θ, ω] T is defined, and the system of first-order ordinary differential equations is as follows: ； r is xyz the direction position vector; v is xyz the direction linear velocity vector; θ is the angle of rotation about the xyz axes; ω is xyz the direction angular velocity vector; Time discretization is carried out using the fourth-order Runge-Kutta method: Calculate the slope: ； Update the state: ； Among them, k 1 is the slope at the previous time point; k 2 is the t n + h slope of / 2, predicted using the increment of ‌k 1; k 3 is the slope at the same intermediate time point t n + h / 2, predicted using the increment of ‌k 2; ‌k 4 is the slope at the next time point t n + h , predicted using the increment 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; After that, rigid body constraint processing is carried out: Euler angles or quaternions are used to avoid singularities; the rotation matrix is orthonormalized after updating the state, and elastic body coupling: the displacement and velocity boundary conditions of the connection points between the discrete sections of the sling and the rigid body are updated synchronously.

7. The construction ship operation parameter optimization system based on the coupled action of wind and waves according to claim 6, characterized in that, The mooring force calculation module includes: Calculate the geometric relationship and define the i position m of the connection point between the hull and the first cable i and the position n of the seabed anchor point i , the instantaneous length of the cable L i (t) is: ； where m i ( t ) is the instantaneous position coordinate of the hull connection point i; L i ( t ) is the length of the i th cable of the hull; The elongation is: ； Among them, Δ L i is the elongation of the i th cable; is the initial length of the i th cable; is the current length of the i th cable; The elongation rate: ； Among them, v i ( t ) is the connection point i of the instantaneous linear velocity; Calculate the non-linear tension and substitute it into the non-linear stiffness model: ； Among them, to represent the non-linear tension of the i th cable at time t; The non-linear stiffness is: ； where, Δ L yield is the yield elongation of the cable; Δ L i is the elongation of the i th cable; k 1,i is the initial linear stiffness of the i th cable at this time; k 2 , i is the initial linear stiffness of the i th cable at this time; Dynamic correction, the relationship between the cable inertia effect and the fluid resistance is: ； Indicates the i total force on the Indicates the i nonlinear tension on the Indicates the drag coefficient of the cable; D represents the cable diameter; v rel =v i t i -V current , v rel represents the difference between the tangential velocity of the cable and the flow velocity; is the unit vector in the cable direction; The cable stress amplitude is: Δσ i = F i / A c ; Among them, A c is the cross-sectional area of the cable; Δσ i represents the i stress amplitude of the nth cable; The fatigue life of the cable is: in, Indicates i Fatigue life of cables; C and s is a material constant, and the damage is accumulated by Miner's criterion.

8. The operation parameter optimization system for a construction ship based on the coupling action of wind and waves according to any one of claims 1-7, characterized in that: It also includes a data visualization and optimization module, which visually displays the calculation results of the motion response and the mooring force, and displays the predicted motion trajectories of the hull and the suspended object, the tension change of the sling, and the force distribution of the mooring cables through a graphical interface, and optimizes the mooring plan and operation strategy of the construction ship.

9. The construction ship operation parameter optimization system based on the coupling action of wind and waves according to 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, which consists of multiple motion capture cameras and acquisition and analysis software. The motion capture cameras complete the task of motion capture by monitoring and tracking the marker points on the measured object.

10. An optimization method for the operation parameters of a construction ship based on the coupled action of wind and waves, characterized in that, Comprising: S1. Establish a multi-body dynamics model and multi-body dynamics equations of the construction ship. The multi-body dynamics model includes a rigid body model constructed based on hull and suspended object parameters, an elastic body model constructed based on sling parameters, and a non-linear spring model constructed based on mooring system parameters; the multi-body dynamics equations include a translational analysis module and a rotational analysis module based on the rigid body model, a tension analysis module based on the elastic body model, and a non-linear deformation analysis module based on the non-linear spring model; S2. Environmental load calculation. First, calculate the forces exerted by environmental loads on the construction vessel, and then use the calculation results as the input to the multi-body dynamics model; S3. Solve the motion responses of the multi-body dynamics model through numerical integration methods. The motion responses include the six-degree-of-freedom motions of the hull and the suspended object, as well as the tension changes in the suspension ropes; S4. Calculate the forces on the mooring system, and calculate the tension distributions of each cable based on the motion responses and the non-linear characteristics of the mooring system; S5. Verify the data accuracy of the multi-body 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 the motion responses and the mooring forces through a graphical interface, and provide prediction results.

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