A method, device, medium and equipment for analyzing a posture of a rake arm of a trailing suction dredger

Abstract

The embodiment of the application discloses a draghead posture analysis method, device, medium and equipment for a trailing suction dredger, which comprises the following steps: regarding the ship body and the draghead of the trailing suction dredger as rigid bodies, regarding the wave compensator of the trailing suction dredger as a flexible body, regarding the fluid-structure interaction added mass of the ship body and the draghead as the rigid body added mass, and constructing the multi-body system block matrix coupling equation of the trailing suction dredger; obtaining an external load vector acting on the trailing suction dredger; and solving the multi-body system block matrix coupling equation of the trailing suction dredger based on the external load vector to obtain the draghead posture of the trailing suction dredger. The embodiment of the application can improve the analysis accuracy when the draghead posture is analyzed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of dredging engineering, and in particular to a method and device for analyzing the posture of a rake arm of a trailing suction hopper dredger, a medium and equipment. BACKGROUND

[0002] With the deepening of the development of marine resources, the design and performance prediction of deepwater operation equipment become increasingly important. As a key component of the offshore platform, the motion characteristics of the rake arm system directly affect the operation efficiency and equipment safety. In the deepwater dredging operation of the existing trailing suction hopper dredger, the ship body has multiple degrees of freedom, the rake arm is segmented and hinged, the large flow of mud-water two-phase flow and the wave compensator are coupled with each other, which makes it difficult to accurately predict the posture and stress of the suction pipeline. When analyzing the posture of the rake arm, the traditional method usually models the ship body, the rake arm and the fluid separately, and then iterates in a weakly coupled manner. However, the traditional method usually ignores the dynamic response characteristics of the wave compensator, which causes the analysis result of the posture of the rake arm to be insufficient in accuracy. SUMMARY

[0003] The embodiments of the present application provide a method and device for analyzing the posture of a rake arm of a trailing suction hopper dredger, a medium and equipment, which can improve the analysis accuracy when analyzing the posture of the rake arm.

[0004] In a first aspect, the embodiments of the present application provide a method for analyzing the posture of a rake arm of a trailing suction hopper dredger, comprising:

[0005] The ship body and the rake arm of the trailing suction hopper dredger are regarded as rigid bodies, the wave compensator of the trailing suction hopper dredger is regarded as a flexible body, and the added mass of the fluid-structure interaction of the ship body and the rake arm is regarded as the added mass of the rigid body to construct a block matrix coupling equation of a multi-body system of the trailing suction hopper dredger;

[0006] An external load vector acting on the trailing suction hopper dredger is obtained; and

[0007] The block matrix coupling equation of the multi-body system of the trailing suction hopper dredger is solved based on the external load vector to obtain the posture of the rake arm of the trailing suction hopper dredger.

[0008] In a second aspect, the embodiments of the present application provide a device for analyzing the posture of a rake arm of a trailing suction hopper dredger, comprising:

[0009] An equation construction module is configured to regard the ship body and the rake arm of the trailing suction hopper dredger as rigid bodies, regard the wave compensator of the trailing suction hopper dredger as a flexible body, and regard the added mass of the fluid-structure interaction of the ship body and the rake arm as the added mass of the rigid body to construct a block matrix coupling equation of a multi-body system of the trailing suction hopper dredger;

[0010] An external load vector obtaining module is configured to obtain an external load vector acting on the trailing suction hopper dredger; and

[0011] An equation solving module is configured to solve the multi-body system block matrix coupling equation of the trailing suction dredger based on the external load vector to obtain the trailing arm posture of the trailing suction dredger.

[0012] In a third aspect, an electronic device is provided, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the trailing arm posture analysis method of any of the embodiments of the present application when executing the program.

[0013] In a fourth aspect, a computer readable storage medium is provided, which stores a computer program executable on a processor to implement the trailing arm posture analysis method of any of the embodiments of the present application.

[0014] The trailing arm posture analysis method, device, medium and electronic device provided by the embodiments of the present application can improve the analysis accuracy when analyzing the trailing arm posture by taking the ship body and the trailing arm of the trailing suction dredger as rigid bodies, taking the wave compensator of the trailing suction dredger as a flexible body, constructing the multi-body system block matrix coupling equation of the trailing suction dredger by taking the added mass of the fluid-structure interaction of the ship body and the trailing arm as the added mass of the rigid body, then obtaining the external load vector of the trailing suction dredger, solving the multi-body system block matrix coupling equation of the trailing suction dredger based on the external load vector to obtain the trailing arm posture of the trailing suction dredger, comprehensively considering the dynamic response characteristics of the ship body and the wave compensator and the influence of the fluid-structure interaction on the trailing arm posture to simulate the trailing suction dredger, and analyzing and determining the trailing arm posture of the trailing suction dredger based on the simulation result. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0016] Figure 1 is a flowchart of the trailing arm posture analysis method of the trailing suction dredger provided by the embodiments of the present application;

[0017] Figure 2 is another flowchart of the trailing arm posture analysis method of the trailing suction dredger provided by the embodiments of the present application;

[0018] Figure 3 is another flowchart of the trailing arm posture analysis method of the trailing suction dredger provided by the embodiments of the present application;

[0019] Figure 4is a structural schematic view of a rake arm posture analysis device of a trailing suction dredger provided by an embodiment of the present application.

[0020] Figure 5 is a structural schematic view of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to enable persons skilled in the art to better understand the present application, 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 a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative work should belong to the protection scope of the present application.

[0022] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0023] Figure 1 is a flowchart of a rake arm posture analysis method of a trailing suction dredger provided by an embodiment of the present application. The embodiment can be applicable to the scene of deep water dredging operation of a trailing suction dredger. The method can be executed by a deep water dredging operation device of a trailing suction dredger provided by an embodiment of the present application. The device can be realized in the form of software and / or hardware. In a specific embodiment, the device can be integrated in an electronic device, such as a computer, a server, etc. The following embodiments will be described by taking the device integrated in an electronic device as an example. Referring to Figure 1 The method can specifically include the following steps:

[0024] In step 101, the hull and the rake arm of the trailing suction dredger are taken as rigid bodies, the wave compensator of the trailing suction dredger is taken as a flexible body, and the fluid-structure interaction added mass of the hull and the rake arm is taken as rigid body added mass to construct the block matrix coupling equation of the multi-body system of the trailing suction dredger. By constructing the block matrix coupling equation of the multi-body system including the hull, the rake arm and the wave compensator and taking the fluid-structure interaction added mass as rigid body added mass, the dynamic response characteristics of the hull and the wave compensator and the influence of the fluid-structure interaction on the rake arm posture are comprehensively considered to simulate the trailing suction dredger, which can improve the analysis accuracy when the rake arm posture is analyzed based on the block matrix coupling equation of the multi-body system.

[0025] Specifically, in the multi-body coupling system, the rigid body can be understood as a non-deformable component with almost unchanged geometric shape and size, which only makes overall translation or rotation movement; the flexible body can be understood as a deformable component which can be elastically deformed, and its movement needs to consider both the overall rigid body movement and the local deformation; the rigid body added mass can be understood as a virtual mass added to the rigid body by the inertia effect of the surrounding medium (such as fluid) when the rigid body interacts with the medium, which affects the overall inertia characteristics of the system.

[0026] Specifically, the rake arm of the trailing suction dredger described above can include two-section rake arms or three-section rake arms.

[0027] Specifically, when the rake arm of the trailing suction dredger includes three-section rake arms, the upper rake arm and the middle rake arm are fixed at the fixed anchor points on the side of the hull through the corresponding rake arm hanger ropes, and the lower rake arm is connected with a rake head at the end and connected with the wave compensator through a hanger rope.

[0028] Specifically, the lower rake arm can also be connected with the wave compensator in other ways, such as through a hinged connection or a spherical hinge connection.

[0029] Optionally, the process of constructing the block matrix coupling equation of the multi-body system of the trailing suction dredger by taking the hull and the rake arm of the trailing suction dredger as rigid bodies, taking the wave compensator of the trailing suction dredger as a flexible body, and taking the fluid-structure interaction added mass of the hull and the rake arm as rigid body added mass includes:

[0030] establishing the corresponding multi-body system generalized coordinates of the hull, the rake arm and the wave compensator; based on the multi-body system generalized coordinates, establishing the rigid body subsystem equation corresponding to the hull and the rake arm, the flexible body subsystem equation corresponding to the wave compensator and the fluid-structure interaction added mass equation; and based on the rigid body subsystem equation, the flexible body subsystem equation and the fluid-structure interaction added mass equation, constructing the block matrix coupling equation of the multi-body system.

[0031] In step 102, an external load vector acting on the trailing suction dredger is obtained. This step can facilitate solving the block matrix coupling equation of the multi-body system based on the external load vector.

[0032] Specifically, the wave excitation force vector acting on the ship body and the current resistance force vector, and the fluid load mapping vector acting on the rake arm can be obtained, and the wave excitation force vector, the current resistance force vector and the fluid load mapping vector are summed to obtain the external load vector of the rake suction dredger.

[0033] Optionally, the process of obtaining the external load vector of the rake suction dredger comprises: obtaining the wave excitation force vector acting on the ship body and the current resistance force vector, and the fluid load mapping vector, the seabed support force vector and the seabed drag force vector acting on the rake arm, and determining the external load vector of the rake suction dredger based on the wave excitation force vector, the current resistance force vector, the fluid load mapping vector, the seabed support force vector and the seabed drag force vector.

[0034] Specifically, the wave excitation force vector can be calculated by measuring the pressure distribution and motion response of the ship body surface through devices such as pressure sensors and acceleration sensors installed on the ship body.

[0035] Specifically, the current resistance force vector can be determined by directly measuring the resistance of the ship body in the current through resistance measuring devices such as tension sensors installed on the ship body.

[0036] Specifically, based on the Morison theory, the fluid load acting on the rake arm can be divided into drag force and inertia force, and then the drag force and inertia force are mapped to the generalized force of the rake arm to obtain the fluid load mapping vector acting on the rake arm.

[0037] Specifically, when the vertical position of the rake head is lower than the elevation of the seabed, the seabed normal support force corresponding to the seabed support force vector can be calculated based on the following formula:

[0038] (1)

[0039] Wherein, represents the seabed normal support force, represents the vertical position of the rake head, represents the seabed height, represents the seabed contact stiffness, represents the seabed damping coefficient, n represents the nonlinear stiffness index, which can be 1.5.

[0040] Specifically, the seabed drag force can be determined based on the dredging depth of the rake suction dredger.

[0041] Specifically, the drag force values at different dredging depths can be determined in advance according to the test results and a depth-drag force mapping table is established, and the process of determining the seabed drag force based on the dredging depth of the rake suction dredger comprises determining the seabed drag force based on the corresponding dredging depth and the depth-drag force mapping table.

[0042] In step 103, the rake arm posture of the cutter suction dredger is solved based on the external load vector and the multi-body system block matrix coupling equation of the cutter suction dredger, thereby obtaining the rake arm posture of the cutter suction dredger. Based on steps 101 and 102, the rake arm posture of the cutter suction dredger is determined by comprehensively considering the dynamic response characteristics of the ship body and the wave compensator and the influence of the fluid-solid interaction on the rake arm posture, so that the analysis accuracy of the rake arm posture is improved.

[0043] Specifically, the ship body motion, the rake arm posture, the rope tension, and the compensator stroke can be obtained by solving the multi-body system block matrix coupling equation of the cutter suction dredger based on the external load vector.

[0044] Specifically, the rake arm posture includes the position parameters, the angle line bundle, and the motion state parameters of each section of the rake arm.

[0045] Optionally, the process of solving the multi-body system block matrix coupling equation of the cutter suction dredger based on the external load vector to obtain the rake arm posture of the cutter suction dredger includes: solving the multi-body system block matrix coupling equation based on the external load vector by using the Newmark β implicit integration method.

[0046] Specifically, the process of solving the multi-body system block matrix coupling equation based on the external load vector by using the Newmark β implicit integration method includes: after each step of integration operation, the joint angle of the rake arm and the rope tension are checked and corrected.

[0047] Specifically, other multi-body system block matrix coupling equations in the prior art can also be used to solve the multi-body system block matrix coupling equation of the cutter suction dredger, such as the iterative solving method.

[0048] The rake arm posture analysis method of the cutter suction dredger provided by the embodiment of the present application will be further introduced below, as shown in FIG. 1. Figure 2 As shown in FIG. 1, step 101 in the embodiment of the present application can include the following steps. Figure 1

[0049] In step 1011, the multi-body system generalized coordinates corresponding to the cutter suction dredger are established based on the six degrees of freedom of the ship body, the rake arm pitch-yaw, and the piston displacement of the wave compensator.

[0050] In a specific example, the multi-body system generalized coordinates can be expressed as:

[0051] , (2)

[0052] wherein, respectively represent the translational displacement of the ship body mass center in the inertial system; respectively represent the pitch, roll, and yaw of the ship body; ​δp, δy, δr respectively represent the pitch, the yaw and the roll of the upper, middle and lower harrow arms; δp, δy, δr respectively represent the pitch, the yaw and the roll of the upper, middle and lower harrow arms;

[0053] In step 1012, the rigid body subsystem equation corresponding to the ship body and the harrow arms, the flexible body subsystem equation corresponding to the wave compensator, the harrow arm hoisting rope constraint equation, the ship body fluid-solid interaction added mass equation, the harrow arm fluid-solid interaction added mass equation and the harrow arm fluid-solid interaction added damping equation are established based on the multi-body system generalized coordinates.

[0054] Specifically, the process of establishing the rigid body subsystem equation corresponding to the ship body includes: establishing the rigid body subsystem equation corresponding to the ship body based on the ship body dry mass matrix, the ship body added mass matrix, the ship body damping matrix, the ship body hydrostatic restoring stiffness matrix and the wave excitation force vector, the sea current resistance vector and the harrow arm reaction force vector.

[0055] Specifically, the rigid body subsystem equation corresponding to the ship body can be expressed as:

[0056] , (3)

[0057] In the formula, δ represents the displacement of the ship body, represents the displacement of the ship body, represents the ship body dry mass matrix, represents the ship body added mass matrix, represents the ship body damping matrix, represents the ship body hydrostatic restoring stiffness matrix, represents the wave excitation force vector, represents the sea current resistance vector, represents the harrow arm reaction force vector.

[0058] Optionally, the process of establishing the rigid body subsystem equation corresponding to the harrow arm includes: for the ith section harrow arm, the rigid body subsystem equation corresponding to the harrow arm is established based on the corresponding upper end hinged moment of inertia, the hinged damping matrix, the hinged stiffness matrix, the tension Lagrange multiplier of the connecting hoisting rope and the fluid load mapping vector.

[0059] Optionally, the rigid body subsystem equation corresponding to the harrow arm includes: the pitch motion equation and the yaw motion equation.

[0060] Specifically, the pitch motion equation can be expressed as:

[0061] , (4)

[0062] The yaw motion equation can be expressed as:

[0063] , (5)

[0064] wherein, and correspond to the pitch angle and the yaw angle of the ith harvester arm; denotes the upper end hinge rotational inertia, , correspond to the pitch motion hinge damping matrix and the yaw motion hinge damping matrix; denotes the mass, denotes the length of the ith harvester arm; and correspond to the pitch motion hinge damping matrix and the yaw motion hinge damping matrix; and correspond to the pitch motion hinge damping matrix and the yaw motion hinge damping matrix; and correspond to the fluid load pitch direction mapping vector and the fluid load pitch direction mapping vector; denotes the tension Lagrange multiplier of the connecting hanger rope, denotes the corresponding force arm.

[0065] Optionally, the harvester arm comprises an upper harvester arm, a middle harvester arm and a lower harvester arm on which a harvester head is mounted. The upper harvester arm and the middle harvester arm are connected with the fixed anchor point on the side of the ship body through the corresponding harvester arm connecting hanger rope; the lower harvester arm is connected with the wave compensator through the harvester head compensator connecting hanger rope.

[0066] Specifically, the lower harvester arm can be connected with the compensation execution component, such as a piston, of the wave compensator through the harvester head compensator connecting hanger rope.

[0067] Optionally, the harvester arm hanger rope constraint equation comprises an upper-middle harvester arm hanger rope constraint equation and a lower harvester arm hanger rope constraint equation.

[0068] Specifically, the harvester arm hanger rope constraint equation can also be one equation.

[0069] Optionally, the process of establishing the flexible body subsystem equation corresponding to the wave compensator comprises:

[0070] establishing the coupling equation of the wave compensator and the harvester head compensator connecting hanger rope based on the tension Lagrange multiplier of the harvester head compensator connecting hanger rope to obtain the flexible body subsystem equation.

[0071] Specifically, the process of establishing the coupling equation of the wave compensator and the harvester head compensator connecting hanger rope based on the tension Lagrange multiplier of the harvester head compensator connecting hanger rope to obtain the flexible body subsystem equation can comprise: establishing the flexible body subsystem equation based on the compensator piston equivalent mass, the piston stroke, the piston damping, the piston reset stiffness and the tension Lagrange multiplier of the harvester head compensator connecting hanger rope.

[0072] Specifically, the flexible body subsystem equation can be expressed as:

[0073] , (6)

[0074] wherein, represents the equivalent mass of the compensator piston, represents the piston stroke, represents the piston damping, represents the piston restoring stiffness, represents the tension Lagrange multiplier of the rake head compensator connecting sling.

[0075] Optionally, the process of establishing the rake arm sling constraint equation of the rake suction dredger based on the generalized coordinates of the multi-body system comprises: establishing the upper-middle rake arm sling constraint equation based on the corresponding rake arm hinge point position coordinates in the generalized coordinates of the multi-body system and the fixed anchor point coordinates of the corresponding rake arm connecting sling on the ship body side, and the length of the corresponding rake arm connecting sling.

[0076] Specifically, for the ith section of the upper-middle rake arm, the upper-middle rake arm sling constraint equation can be expressed as:

[0077] , (7)

[0078] wherein, represents the rake arm hinge point position coordinates, represents the fixed anchor point coordinates of the corresponding rake arm connecting sling on the ship body side, represents the length of the corresponding rake arm connecting sling.

[0079] Optionally, the process of establishing the rake arm sling constraint equation of the rake suction dredger based on the generalized coordinates of the multi-body system comprises: establishing the lower rake arm sling constraint equation based on the corresponding rake head center position coordinates in the generalized coordinates of the multi-body system and the wave compensator installation base point coordinates, the wave compensator piston stroke variable, and the initial length of the rake head compensator connecting sling.

[0080] Specifically, the lower rake arm sling constraint equation can be expressed as:

[0081] , (8)

[0082] wherein, represents the rake head center position coordinates, represents the wave compensator installation base point coordinates, represents the initial length of the rake head compensator connecting sling, represents the piston stroke.

[0083] Specifically, the ship body fluid-solid interaction additional equation can be expressed as:

[0084] , (9)

[0085] wherein, represents the hull fluid-structure interaction added mass, represents the fluid density, represents the unit velocity potential, represents the normal component, represents the infinitesimal area.

[0086] Optionally, the rake arm fluid-structure interaction added mass equation comprises: a rake arm outer fluid-structure interaction added mass equation and a rake arm inner fluid-structure interaction added mass equation.

[0087] Specifically, the rake arm fluid-structure interaction added mass equation can only comprise one equation.

[0088] Optionally, the process of establishing the rake arm fluid-structure interaction added mass equation comprises: establishing the rake arm outer fluid-structure interaction added mass equation based on the Morison equation.

[0089] Specifically, the fluid load on the rake arm can be divided into drag force and inertia force based on the Morison equation, wherein part of the inertia force can be decomposed into a generalized force term of pure external stimulus independent of the rake arm motion and an added mass force term of reaction water body inertia resistance, wherein the added mass force term can be represented as:

[0090]

[0091] The rake arm fluid-structure interaction added mass equation can be represented as:

[0092] , (10)

[0093] wherein, represents the inertia force, represents the inertia coefficient, and D represents the outer diameter of the rake arm, represents the velocity vector of the rake arm relative to the fluid, represents the rake arm outer fluid-structure interaction added mass.

[0094] Optionally, the process of establishing the rake arm fluid-structure interaction added mass equation comprises: establishing the rake arm inner fluid-structure interaction added mass equation based on the cement two-phase flow model.

[0095] Specifically, the rake arm fluid-structure interaction added damping equation can also be established based on the cement two-phase flow model.

[0096] Specifically, the rake arm inner fluid-structure interaction added mass equation and the rake arm fluid-structure interaction added damping equation are as follows.

[0097] Rake arm inner fluid-structure interaction added mass equation:

[0098] , (11)

[0099] The additional damping equation of the rake arm fluid-structure interaction is:

[0100] , (12)

[0101] wherein, represents the additional mass of the fluid-structure interaction in the rake arm, represents an empirical coefficient about 0.6, represents the mixed density, represents the pipe cross-sectional area in the rake arm, L represents the rake arm length, ζ represents the additional damping ratio, and k is the relevant stiffness, represents the additional damping of the rake arm fluid-structure interaction.

[0102] Step 1013, based on the rigid body subsystem equation, the flexible body subsystem equation, the rake arm rope constraint equation, the ship hull fluid-structure interaction additional mass equation, the rake arm fluid-structure interaction additional mass equation, and the rake arm fluid-structure interaction additional damping equation, the multi-body system block matrix coupling equation is established.

[0103] In one specific example, the process of establishing the multi-body system block matrix coupling equation based on the rigid body subsystem equation, the flexible body subsystem equation, the rake arm rope constraint equation, the ship hull fluid-structure interaction additional mass equation, the rake arm fluid-structure interaction additional mass equation, and the rake arm fluid-structure interaction additional damping equation includes: based on the rigid body subsystem equations (3), (4) and (5), the flexible body subsystem equation (6), the rake arm rope constraint equations (7) and (8), the ship hull fluid-structure interaction additional mass equation (9), the rake arm fluid-structure interaction additional mass equations (10) and (11), and the rake arm fluid-structure interaction additional damping equation (12), the above multi-body system block matrix coupling equation is established.

[0104] Specifically, the above multi-body system block matrix coupling equation can be represented as:

[0105] , (13)

[0106] wherein M and K represent the generalized mass matrix and the generalized stiffness matrix determined based on equations (3), (4) and (5),

[0107] , ;

[0108] C represents the generalized damping matrix determined based on equations (3), (4), (5) and (12), ; represents the additional mass matrix determined based on equations (3), (9), (10) and (11), ; , and Corresponding represents the equivalent mass, damping and stiffness of the wave compensator determined based on formula (6); G=∂g / ∂U represents the rake arm sling constraint equation of formula (7) and formula (8); g=[g t1 ,g t2 ,g tc ] T The Jacobian matrix with respect to the generalized coordinates U; represents the unit vector of the wave compensator, which is used to extract the wave compensator piston degree of freedom; λ represents the tension Lagrange multiplier vector of the upper-middle rake arm connecting sling and the rake head compensator connecting sling determined based on formula (4), (6), (7) and (8), λ=[λ t1 ,λ t2 ,λ c ]T is the tension Lagrange multiplier vector of the three slings; represents the external load vector determined based on formula (1), (3), (4) and (5), ; represents the reciprocal of formula (7) and (8), which is a constraint stabilization term.

[0109] The embodiment of the application can improve the accuracy of the simulation of the rake suction dredger, so as to improve the analysis accuracy when analyzing the rake arm posture.

[0110] The rake arm posture analysis method of the rake suction dredger provided by the embodiment of the application will be further introduced below.

[0111] Optionally, as shown in Figure 3 , the process of establishing the rigid body subsystem equation of the rake arm includes:

[0112] Step 1012A, determining the stiffness term of the pitch motion equation based on the maximum allowed pitch angle and the penalty stiffness.

[0113] Specifically, the pitch motion hinged stiffness matrix of the pitch motion equation can be determined based on the following formula , and then the stiffness term is determined based on the hinged stiffness matrix:

[0114] , (14)

[0115] Wherein, represents the pitch angle of the ith section of the rake arm; represents the valve stiffness (typical value 1e6~1e8 N·m / rad); represents the maximum allowed pitch angle; p represents a nonlinear index (which can be 1 or 2).

[0116] Step 1012B, determining the damping term of the pitch motion equation based on the maximum allowed pitch angle, the step function and the impact damping coefficient.

[0117] Specifically, the pitch motion hinge damping matrix of the pitch motion equation can be determined based on the following formula, and the damping term can be determined based on the pitch motion hinge damping matrix:

[0118] (15)

[0119] Wherein, H() represents the step function (if out of limit = 1, otherwise = 0); represents the pitch angle of the ith section of the rake arm; represents the impact damping coefficient (typical value 1e4~1e5 N·m·s / rad).

[0120] Step 1012C, determining the generalized force term of the pitch motion equation based on the tension Lagrange multiplier of the rake arm connecting the sling rope.

[0121] The embodiment of the present application adds the joint physical limiting mechanism and the hinge friction loss in the rigid body subsystem equation corresponding to the rake arm, which can further improve the accuracy of the simulation of the rake suction dredger, thereby further improving the subsequent rake arm posture analysis accuracy.

[0122] Figure 4 is a structural diagram of the rake arm posture analysis device of the rake suction dredger provided by the embodiment of the present application, which is suitable for executing the rake arm posture analysis method of the rake suction dredger provided by the embodiment of the present application. As shown in Figure 4 , the device can specifically include:

[0123] The equation construction module 401 is configured to construct the multi-body system block matrix coupling equation of the rake suction dredger by taking the ship body and the rake arm of the rake suction dredger as rigid bodies, taking the wave compensator of the rake suction dredger as a flexible body, and taking the fluid-structure interaction added mass of the ship body and the rake arm as rigid body added mass. By constructing the multi-body system block matrix coupling equation including the ship body, the rake arm and the wave compensator, and taking the fluid-structure interaction added mass as the rigid body added mass, the dynamic response characteristics of the ship body and the wave compensator and the influence of the fluid-structure interaction on the rake arm posture are comprehensively considered to simulate the rake suction dredger, which can improve the analysis accuracy when the rake arm posture is analyzed based on the multi-body system block matrix coupling equation.

[0124] Optionally, the equation construction module 401 can be specifically configured to: establish a multi-body system generalized coordinate of the trailing suction dredger based on a six-degree-of-freedom of a hull of the trailing suction dredger, a rake arm pitch-yaw, and a piston displacement of a wave compensator; establish a rigid body subsystem equation of the hull and the rake arm, a flexible body subsystem equation of the wave compensator, a rake arm hoisting rope constraint equation, a hull fluid-structure interaction added mass equation, a rake arm fluid-structure interaction added mass equation, and a rake arm fluid-structure interaction added damping equation based on the multi-body system generalized coordinate; and construct a multi-body system block matrix coupling equation based on the rigid body subsystem equation, the flexible body subsystem equation, the rake arm hoisting rope constraint equation, the hull fluid-structure interaction added mass equation, the rake arm fluid-structure interaction added mass equation, and the rake arm fluid-structure interaction added damping equation.

[0125] Optionally, the rigid body subsystem equation of the rake arm includes a pitch motion equation and a yaw motion equation, and the equation construction module 401 can be specifically configured to: determine a stiffness term of the pitch motion equation based on a maximum allowed pitch angle and a penalty stiffness; determine a damping term of the pitch motion equation based on the maximum allowed pitch angle, a step function, and an impact damping coefficient; and determine a generalized force term of the pitch motion equation based on a tension Lagrange multiplier of a rake arm connecting hoisting rope.

[0126] Optionally, the rake arm includes an upper rake arm, a middle rake arm, and a lower rake arm on which a rake head is mounted; the upper rake arm and the middle rake arm are connected to fixed anchor points on a side of the hull through corresponding rake arm connecting hoisting ropes; the lower rake arm is connected to the wave compensator through a rake head compensator connecting hoisting rope; and the rake arm hoisting rope constraint equation includes an upper-middle rake arm hoisting rope constraint equation and a lower rake arm hoisting rope constraint equation.

[0127] Optionally, the equation construction module 401 can be specifically configured to: establish a coupling equation of the wave compensator and the rake head compensator connecting hoisting rope based on a tension Lagrange multiplier of the rake head compensator connecting hoisting rope to obtain the flexible body subsystem equation.

[0128] Optionally, the equation construction module 401 can be specifically configured to: establish the upper-middle rake arm hoisting rope constraint equation based on corresponding rake arm hinge point position coordinates in the multi-body system generalized coordinate, fixed anchor point coordinates of corresponding rake arm connecting hoisting ropes on the side of the hull, and lengths of the corresponding rake arm connecting hoisting ropes; and establish the lower rake arm hoisting rope constraint equation based on corresponding rake head center position coordinates in the multi-body system generalized coordinate, wave compensator mounting base point coordinates, a wave compensator piston stroke variable, and an initial length of the rake head compensator connecting hoisting rope.

[0129] Optionally, the rake arm fluid-structure interaction added mass equation includes an outer rake arm fluid-structure interaction added mass equation and an inner rake arm fluid-structure interaction added mass equation.

[0130] Optionally, the equation establishing module 401 can be specifically configured to establish a rake arm outflow fluid-structure interaction added mass equation based on the Morison equation, and establish a rake arm inflow fluid-structure interaction added mass equation based on a cement two-phase flow model.

[0131] The external load vector acquisition module 402 is configured to acquire an external load vector acting on the rake suction dredger. The external load vector can be used to solve the multi-body system block matrix coupling equation.

[0132] Optionally, the external load vector acquisition module 402 can be specifically configured to acquire a wave excitation force vector and a sea current resistance vector acting on the ship body, and a fluid load mapping vector, a seabed support force vector and a seabed drag force vector acting on the rake arm, and determine the external load vector of the rake suction dredger based on the wave excitation force vector, the sea current resistance vector, the fluid load mapping vector, the seabed support force vector and the seabed drag force vector.

[0133] The equation solving module 403 is configured to solve the multi-body system block matrix coupling equation of the rake suction dredger based on the external load vector to obtain the rake arm posture of the rake suction dredger.

[0134] Optionally, the equation solving module 403 can be specifically configured to solve the multi-body system block matrix coupling equation based on the external load vector by using the Newmark method. The dynamic response characteristics of the ship body and the wave compensator and the influence of the fluid-structure interaction on the rake arm posture can be comprehensively considered by combining the module 401 and the module 402 to determine the rake arm posture of the rake suction dredger, and the analysis accuracy of the rake arm posture can be improved.

[0135] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional modules is exemplified, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. The specific working process of the above described functional modules can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0136] The embodiment of the present application also provides an electronic device, which comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the rake arm posture analysis method of the rake suction dredger provided by any of the above embodiments when executing the program.

[0137] The embodiment of the present application also provides a computer readable medium having a computer program stored thereon, and the program is executed by a processor to implement the rake arm posture analysis method of the rake suction dredger provided by any of the above embodiments.

[0138] The embodiment of the present application further provides a computer program product comprising a computer program which, when executed by a processor, implements the rake arm posture analysis method of the trailing suction dredger as any of the embodiments of the present application.

[0139] Reference will now be made to the following description Figure 5 which shows a schematic diagram of a computer system 500 suitable for implementing the electronic device of the embodiments of the present application. Figure 5 The electronic device shown is merely an example and should not impose any limitation on the functions and usage range of the embodiments of the present application.

[0140] As shown in Figure 5 , the computer system 500 comprises a central processing unit (CPU) 501 which can perform various appropriate actions and processes according to programs stored in a read-only memory (ROM) 502 or programs loaded from a storage portion 508 into a random access memory (RAM) 503. In the RAM 503, various programs and data required for the operation of the system 500 are also stored. The CPU 501, the ROM 502 and the RAM 503 are connected to each other through a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0141] The following components are connected to the I / O interface 505: an input portion 506 comprising a keyboard, a mouse, etc.; an output portion 507 comprising a display such as a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage portion 508 comprising a hard disk, etc.; and a communication portion 509 comprising a network interface card such as a LAN card, a modem, etc. The communication portion 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to the I / O interface 505 as necessary. A removable media 511 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc. is mounted on the drive 510 as necessary so that a computer program read therefrom is installed into the storage portion 508 as necessary.

[0142] In particular, the processes described above with reference to the flowcharts can be implemented as a computer software program according to the embodiments disclosed in the present application. For example, the embodiments disclosed in the present application comprise a computer program product comprising a computer program carried on a computer readable medium, the computer program containing program codes for executing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network by the communication portion 509 and / or installed from the removable media 511. When the computer program is executed by the central processing unit (CPU) 501, the above-mentioned functions defined in the system of the present application are performed.

[0143] It should be noted that the computer-readable medium shown in the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may, for example, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or component, or any combination of the above. More specific examples of computer-readable storage media can include, but are not limited to, an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device or component. In the present application, the computer-readable signal medium can include a data signal carried in a baseband or as a part of a carrier wave, which carries computer-readable program code. Such a propagated data signal can take various forms, including but not limited to an electromagnetic signal, an optical signal or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than the computer-readable storage medium, which can send, propagate or transmit a program for use by or in conjunction with an instruction execution system, device or component. The program code contained on the computer-readable medium can be transmitted by any suitable medium, including but not limited to wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0144] The flowcharts and block diagrams in the drawings illustrate the possible implementation architectures, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowcharts or block diagrams can represent a module, a program segment or a part of code containing one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur in different order than that shown in the drawings. For example, two blocks that are shown in succession can actually be executed substantially in parallel, and sometimes in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams or flowcharts, and the combination of blocks in the block diagrams or flowcharts, can be implemented by a dedicated hardware-based system that performs the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0145] The modules and / or units described in the embodiments of the present application can be implemented by software, or by hardware, or by a combination of software and hardware. The described modules and / or units can also be arranged in a processor, for example, can be described as: a processor includes an equation construction module, an external load vector acquisition module, and an equation solving module. Among them, the name of the module does not constitute a limitation of the module itself in some cases.

[0146] As another aspect, the present application also provides a computer readable medium, which can be included in the device described in the above embodiments, or can exist independently without being assembled into the device. The computer readable medium carries one or more programs, when the one or more programs are executed by the device, the device includes: constructing a block matrix coupling equation of a multi-body system of the trailing suction dredger, taking the ship body and the rake arm of the trailing suction dredger as a rigid body, taking the wave compensator of the trailing suction dredger as a flexible body, and taking the fluid-structure interaction added mass of the ship body and the rake arm as the rigid body added mass; acquiring an external load vector acting on the trailing suction dredger; and solving the block matrix coupling equation of the multi-body system of the trailing suction dredger based on the external load vector to obtain the rake arm posture of the trailing suction dredger.

[0147] The specific embodiments described above do not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can occur depending on design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method of analyzing a posture of a rake arm of a trailing suction dredger, characterized by, The method comprises the following steps: a multi-body system block matrix coupling equation of the trailing suction hopper dredger is constructed by taking the ship body and the rake arm of the trailing suction hopper dredger as rigid bodies, taking the wave compensator of the trailing suction hopper dredger as a flexible body, and taking the fluid-structure interaction added mass of the ship body and the rake arm as the rigid body added mass; an external load vector acting on the trailing suction hopper dredger is obtained; and a rake arm posture of the trailing suction hopper dredger is obtained by solving the multi-body system block matrix coupling equation of the trailing suction hopper dredger based on the external load vector.

2. The trailing suction hopper dredger boom posture analysis method according to claim 1, characterized in that, The method for constructing the multi-body system block matrix coupling equation of the trailing suction hopper dredger by taking the ship body and the rake arm of the trailing suction hopper dredger as rigid bodies, taking the wave compensator of the trailing suction hopper dredger as a flexible body, and taking the fluid-structure interaction added mass of the ship body and the rake arm as the rigid body added mass comprises the following steps: a corresponding multi-body system generalized coordinate of the trailing suction hopper dredger is established based on the six degrees of freedom of the ship body, the rake arm pitch-yaw, and the piston displacement of the wave compensator; a corresponding rigid body subsystem equation of the ship body and the rake arm, a corresponding flexible body subsystem equation of the wave compensator, a rake arm hoisting rope constraint equation, a ship body fluid-structure interaction added mass equation, a rake arm fluid-structure interaction added mass equation, and a rake arm fluid-structure interaction added damping equation are established based on the multi-body system generalized coordinate; and the multi-body system block matrix coupling equation is constructed based on the rigid body subsystem equation, the flexible body subsystem equation, the rake arm hoisting rope constraint equation, the ship body fluid-structure interaction added mass equation, the rake arm fluid-structure interaction added mass equation, and the rake arm fluid-structure interaction added damping equation.

3. The trailing suction hopper dredger boom posture analysis method according to claim 2, characterized in that, The rigid body subsystem equation corresponding to the rake arm comprises a pitch motion equation and a yaw motion equation. The method for establishing the rigid body subsystem equation corresponding to the rake arm comprises the following steps: a stiffness term of the pitch motion equation is determined based on a maximum allowable pitch angle and a penalty stiffness; a damping term of the pitch motion equation is determined based on a maximum allowable pitch angle, a step function, and an impact damping coefficient; and a generalized force term of the pitch motion equation is determined based on a tension Lagrange multiplier of a rake arm connecting hoisting rope.

4. The trailing suction hopper dredger rake arm posture analysis method according to claim 2, wherein the rake arm comprises an upper rake arm, a middle rake arm, and a lower rake arm provided with a rake head; the upper rake arm and the middle rake arm are connected with fixed anchor points on the ship body side through corresponding rake arm connecting hoisting ropes; and the lower rake arm is connected with the wave compensator through a rake head compensator connecting hoisting rope; the rake arm hoisting rope constraint equation comprises an upper-middle rake arm hoisting rope constraint equation and a lower rake arm hoisting rope constraint equation; the method for establishing the flexible body subsystem equation corresponding to the wave compensator comprises the following steps: a coupling equation of the wave compensator and the rake head compensator connecting hoisting rope is established based on a tension Lagrange multiplier of the rake head compensator connecting hoisting rope to obtain the flexible body subsystem equation; the method for establishing the rake arm hoisting rope constraint equation of the trailing suction hopper dredger based on the multi-body system generalized coordinate comprises the following steps: an upper-middle rake arm hoisting rope constraint equation is established based on the position coordinates of corresponding rake arm hinges in the multi-body system generalized coordinate, the fixed anchor point coordinates of corresponding rake arm connecting hoisting ropes on the ship body side, and the lengths of the corresponding rake arm connecting hoisting ropes. The lower rake arm rope constraint equation is established based on corresponding rake head center position coordinates in the multi-body system generalized coordinates, wave compensator installation base point coordinates, wave compensator piston stroke variables, and initial lengths of rake head compensator connecting halyards.

5. The trailing suction hopper dredger boom posture analysis method according to claim 2, characterized in that, The rake arm fluid-structure interaction additional mass equation includes an outer rake arm fluid-structure interaction additional mass equation and an inner rake arm fluid-structure interaction additional mass equation. The rake arm fluid-structure interaction additional mass equation is established by: The outer rake arm fluid-structure interaction additional mass equation is established based on the Morison equation; and The inner rake arm fluid-structure interaction additional mass equation is established based on a cement two-phase flow model.

6. The trailing suction hopper dredger boom posture analysis method according to claim 1, characterized in that, The external load vector acting on the rake suction dredger is obtained by: The wave excitation force vector and the sea current resistance vector acting on the ship body, the fluid load mapping vector, the seabed support force vector, and the seabed drag force vector acting on the rake arm are obtained, and the external load vector of the rake suction dredger is determined based on the wave excitation force vector, the sea current resistance vector, the fluid load mapping vector, the seabed support force vector, and the seabed drag force vector.

7. The trailing suction hopper dredger boom posture analysis method according to claim 1, characterized in that, The multi-body system block matrix coupling equation of the rake suction dredger is solved based on the external load vector by: The multi-body system block matrix coupling equation is solved based on the external load vector by using the Newmark method.

8. A device for analyzing a posture of a rake arm of a trailing suction dredger, characterized in that, The method comprises: An equation construction module is configured to construct the multi-body system block matrix coupling equation of the rake suction dredger by taking the ship body and the rake arm of the rake suction dredger as rigid bodies, taking the wave compensator of the rake suction dredger as a flexible body, and taking the fluid-structure interaction additional mass of the ship body and the rake arm as rigid body additional mass; An external load vector obtaining module is configured to obtain an external load vector acting on the rake suction dredger; and An equation solving module is configured to solve the multi-body system block matrix coupling equation of the rake suction dredger based on the external load vector to obtain the rake arm posture of the rake suction dredger.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to implement the rake arm posture analysis method of the rake suction dredger as claimed in any one of claims 1 to 7.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the rake arm posture analysis method of the rake suction dredger as claimed in any one of claims 1 to 7.

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