Method and system for rov current and wake interference analysis for offshore wind farms

Abstract

The application discloses a ROV ocean current and wake interference analysis method and system for offshore wind farms, comprising the following steps: calculating the tidal current velocity vector of different depths of the ocean current shallow layer, and calculating the wake velocity vector; obtaining the projection velocity component of the tidal current velocity vector of different depths of the ocean current shallow layer; dividing the operation of the ROV into a wake-free influence area, a wake and ocean current direction consistent influence area and a direction opposite influence area; obtaining the projection velocity component of the wake velocity vector; constructing a final velocity calculation relationship formula of the superposition of the ocean current and wake influence according to the projection velocity component; calculating the final velocity of the superposition of the ocean current and wake influence; calculating the relative velocity component of the superposition of the ocean current and wake influence, and updating the relative velocity component in the damping matrix of the kinetic model of the ROV to the relative velocity component of the superposition of the ocean current and wake influence. The application effectively solves the problems of insufficient ocean current modeling dimension, wake disturbance not considered and weak path interference analysis capability in the path interference analysis of the offshore wind farm inspection ROV.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of offshore wind farm inspection, in particular to a ROV ocean current and wake interference analysis method and system for offshore wind farms. BACKGROUND

[0002] The remotely operated vehicle (ROV) plays an important role in the inspection of offshore wind farms. It can dive underwater and conduct a comprehensive inspection of the underwater foundation structure of the wind farm, such as single pile foundation, gravity foundation, etc. At the same time, it can also inspect the laying of underwater cables and check whether the cables are worn, broken, or entangled with foreign objects. Compared with the traditional manual diving inspection method, the ROV has the advantages of high work efficiency, good safety, long-time continuous operation, etc. It can quickly and accurately obtain detailed information of underwater facilities, provide reliable data support for the operation and maintenance personnel of the wind farm, timely discover potential hidden dangers and take measures to repair them, ensure the safe and stable operation of offshore wind farms, reduce operation and maintenance costs, and improve the overall operation efficiency of the wind farm.

[0003] Path planning and motion control of the ROV are the core technologies to ensure the success of the task execution. Due to the existence of complex ocean current interference, irregular obstacle distribution, and dynamic changes of the target in the underwater environment, the path planning needs to have strong environmental perception ability, disturbance resistance and dynamic adjustment ability. Therefore, researchers usually use simulation analysis systems to analyze the path interference before deployment, in order to reduce the risk and cost in actual operation.

[0004] The current path interference analysis mainly has the following common technical bottleneck problems:

[0005] 1. Unable to simulate three-dimensional non-uniform ocean current environment, most systems only support two-dimensional or simplified constant flow model, which is difficult to accurately reflect the three-dimensional ocean current characteristics varying with depth and region in real sea;

[0006] 2. Ignoring the wake disturbance effect, i.e. not considering the wake disturbance caused by target objects or surrounding structures when the ROV approaches the target area, resulting in deviation of the trajectory simulation result from the actual situation;

[0007] 3. Lack of visualization and data output capability for trajectory disturbance, which makes it difficult to assist users in pre-evaluation or path adjustment analysis of specific operation areas;

[0008] In summary, the existing technology has not realized the joint modeling and analysis of three-dimensional ocean current disturbance and target wake effect, and the path feedback mechanism, which limits the path planning accuracy of the offshore wind farm inspection ROV and the engineering reference value of the analysis result in complex underwater environment. SUMMARY

[0009] The first object of the present application is to overcome the deficiencies of the prior art and provide an ROV ocean current and wake interference analysis method for offshore wind farms, which effectively solves the problems of insufficient ocean current modeling dimensions, not considering wake disturbance, and weak path interference analysis capability in the path interference analysis of the remotely operated underwater vehicle for offshore wind farm inspection.

[0010] The second object of the present application is to provide an ROV ocean current and wake interference analysis method system for offshore wind farms.

[0011] The third object of the present application is to provide a non-transitory computer readable medium.

[0012] The fourth object of the present application is to provide a computing device.

[0013] The first object of the present application is achieved by the following technical solutions:

[0014] An ROV ocean current and wake interference analysis method for offshore wind farms, comprising the steps of,

[0015] According to the tidal current velocity vector on the static water surface of the offshore wind farm, the tidal current velocity vector at different depths of the shallow layer of the ocean current is calculated using a power-law model; and the wake velocity vector is calculated according to the tidal current velocity vector on the static water surface of the offshore wind farm;

[0016] A three-dimensional vector model of the ocean current is constructed, the flow direction of the ocean current is decomposed, and the projection velocity components of the tidal current velocity vector at different depths of the shallow layer of the ocean current in the three principal axis directions are obtained;

[0017] According to the influence of the wake, the operation of the remotely operated underwater vehicle (ROV) is divided into a wake-free influence area, a wake and ocean current direction consistent influence area, and a wake and ocean current direction opposite influence area;

[0018] A two-dimensional vector model of the wake is constructed, the flow direction of the wake is decomposed, and the projection velocity components of the wake velocity vector in the X-axis and Y-axis directions are obtained;

[0019] The projection velocity components of the tidal current velocity vector at different depths of the shallow layer of the ocean current and the projection velocity components of the wake velocity vector are combined to construct the final velocity calculation relationship of the superposition of the ocean current and wake influence in each influence area;

[0020] The heading is determined according to the initial position and target position of the ROV, the influence area in which the ROV is located is determined according to the included angle between the heading and the sea current, and then the final velocity of the superposition of the ocean current and wake influence is calculated according to the corresponding final velocity calculation relationship of the superposition of the ocean current and wake influence;

[0021] The relative velocity component of the superimposed ocean current and wake effect is calculated according to the final velocity of the superimposed ocean current and wake effect, and the relative velocity component in the damping matrix of the dynamic model of the ROV is updated to the relative velocity component of the superimposed ocean current and wake effect, so as to complete the analysis of the comprehensive influence of the ocean current wake on the ROV path.

[0022] Further, the tidal current velocity vector at different depths of the ocean current shallow layer is calculated according to the tidal current velocity vector on the calm water surface by using a power law model,

[0023]

[0024] wherein V c is the tidal current velocity vector on the calm water surface, v c,tide (z) is the tidal current velocity vector at a depth of z, z is the distance above the calm water surface, positive upward, d is the water depth, and e is the index.

[0025] Further, the wake velocity vector is calculated according to the tidal current velocity vector on the calm water surface,

[0026] V f = V c (1-△) (2);

[0027] wherein V c is the tidal current velocity vector on the calm water surface, V f is the wake velocity vector, and△ is the wake velocity loss coefficient, the value range of which is determined according to the shape, size and flow direction angle of the obstacle.

[0028] Further, a three-dimensional vector model of the ocean current is constructed, the flow direction of the ocean current is decomposed in the Cartesian space coordinate system, and the projection velocity components of the tidal current velocity vector at different depths of the ocean current shallow layer in three principal axis directions are obtained, and the mathematical expression is:

[0029]

[0030] wherein V current is the component of the simple ocean current velocity, v c,tide (z) is the tidal current velocity vector at a depth of z, β is the angle between the ocean current vector and the ZOX plane of the Cartesian space coordinate system, and α is the angle between the ocean current vector and the XOY plane of the Cartesian space coordinate system, are respectively the projection velocity components of the tidal current velocity vector at different depths of the ocean current shallow layer in the X axis, Y axis and Z axis.

[0031] Further, a two-dimensional vector model of the wake is constructed, the flow direction of the wake is decomposed in the local coordinate system, and the projection velocity components of the wake velocity vector in the X axis and Y axis directions are obtained, and the mathematical expression is:

[0032]

[0033] wherein, V wake is the component of the pure wake velocity, and β is the included angle between the wake vector and the X axis of the body coordinate system of the ROV, are the projection velocity components of the wake velocity vector in the X axis and Y axis directions, respectively.

[0034] Further, the wake-free influence area is not affected by the wake, the wake and the current direction consistent influence area is affected by the wake and the current direction consistent, the wake velocity loss coefficient Δ = 0.5, the wake and the current direction opposite influence area is affected by the wake and the current direction opposite, the wake velocity loss coefficient Δ = 0.3.

[0035] Further, the superimposed current and wake influence final velocity calculation relationship of the wake-free influence area is V final = V current (5);

[0036] wherein, V final is the superimposed current and wake influence final velocity, and V current is the component of the pure current velocity;

[0037] The superimposed current and wake influence final velocity calculation relationship of the wake and current direction consistent influence area is V

[0038]

[0039] wherein, V x , V y , V z are the projection velocity components of the superimposed current and wake influence final velocity in the X axis, Y axis, and Z axis, respectively, are the projection velocity components of the tidal current velocity vector in the X axis, Y axis, and Z axis at different depths of the current shallow layer, respectively, are the projection velocity components of the wake velocity vector in the X axis and Y axis directions, respectively;

[0040] The superimposed current and wake influence final velocity calculation relationship of the wake and current direction opposite influence area is V

[0041]

[0042] Further, the heading of the ROV, i.e. the direction of approaching the target, is determined according to the initial position and target position of the ROV, if the included angle ω between the direction of approaching the target of the ROV and the current is ∈ [-45°, +45°], the ROV is in the wake-free influence area, and then the superimposed current and wake influence final velocity is calculated by formula (5);

[0043] If the included angle ω between the direction of the ROV approaching the target and the ocean current is ω ∈ (45°, 135°) ∪ (225°, -45°), the ROV is in the area where the wake and the ocean current direction are consistent, and then the final speed of the superposition of the ocean current and the wake is calculated by using formula (6);

[0044] If the included angle ω between the direction of the ROV approaching the target and the ocean current is ω ∈ [135°, 225°], the ROV is in the area where the wake and the ocean current direction are opposite, and then the final speed of the superposition of the ocean current and the wake is calculated by using formula (7).

[0045] Further, the relative speed component of the superposition of the ocean current and the wake is calculated according to the final speed of the superposition of the ocean current and the wake and the relative speed component in the damping matrix of the dynamic model of the ROV,

[0046]

[0047] Wherein, X u , Y v , Z w are linear damping coefficients of X, Y and Z axes in the damping matrix of the dynamic model of the ROV, D u1 , D v1 , D w1 are linear damping coefficients of X, Y and Z axes of the superposition of the ocean current and the wake, v is a speed vector, defined as: v = [u, v, w, p, q, r] T , u, v and w are linear speed components, and p, q and r are angular speed components.

[0048] The relative speed component in the damping matrix is updated to the relative speed component of the superposition of the ocean current and the wake, the analysis of the comprehensive influence of the ocean current and the wake on the ROV path is completed, and the damping matrix after updating the component is,

[0049]

[0050] Wherein, K p , M q , N r are rotational damping coefficients of the angular speed direction around X, Y and Z axes.

[0051] The second object of the application is realized by the following technical scheme:

[0052] An ROV ocean current and wake interference analysis system for offshore wind farms is used to realize the ROV ocean current and wake interference analysis method for offshore wind farms described above, comprising,

[0053] An ocean current calculation module is used to calculate the tidal current velocity vector at different depths of the shallow layer of the ocean current according to the tidal current velocity vector on the static water surface of the offshore wind farm by using a power law model.

[0054] a wake flow calculation module configured to calculate a wake flow velocity vector according to a tidal flow velocity vector on a static water surface of the offshore wind farm;

[0055] a current decomposition module configured to construct a three-dimensional vector model of the current, decompose a current flow direction, and obtain a projection velocity component of the tidal flow velocity vector at different depths of the current shallow layer in three principal axis directions;

[0056] a region division module configured to divide a running region of a remotely operated vehicle (ROV) into a wake flow non-influence region, a wake flow and current direction consistent influence region, and a wake flow and current direction opposite influence region according to influences of the wake flow;

[0057] a wake flow decomposition module configured to construct a two-dimensional vector model of the wake flow, decompose a wake flow direction, and obtain a projection velocity component of the wake flow velocity vector in X-axis and Y-axis directions;

[0058] a relationship construction module configured to construct a final velocity calculation relationship of superimposed wake flow and current influences in each influence region respectively according to the projection velocity components of the tidal flow velocity vector at different depths of the current shallow layer and the projection velocity components of the wake flow velocity vector;

[0059] a final velocity calculation module configured to determine a heading according to an initial position and a target position of the ROV, determine an influence region of the ROV according to an included angle between the heading and the current, and then calculate a final velocity of superimposed wake flow and current influences according to the final velocity calculation relationship of superimposed wake flow and current influences corresponding to the influence region;

[0060] a damping matrix updating module configured to calculate a relative velocity component of superimposed wake flow and current influences according to the final velocity of superimposed wake flow and current influences, and update the relative velocity component in a damping matrix of a dynamics model of the ROV to the relative velocity component of superimposed wake flow and current influences.

[0061] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0062] 1. The present application supports three-dimensional complex current environment modeling

[0063] Traditional ROV path interference analysis mostly adopts a two-dimensional constant flow model, which is difficult to simulate a three-dimensional current structure varying with space in a real sea area. The present application introduces a configurable three-dimensional velocity field, so that the user can define the flow rate and direction of the current in different spatial regions, thereby improving the expression ability of the model to a non-uniform environment and providing more actual simulation conditions for path evaluation of the offshore wind farm inspection ROV.

[0064] 2. Introducing a wake flow interference modeling mechanism

[0065] Existing path disturbance analysis generally ignores the wake disturbance faced by remotely operated vehicles (ROVs) when approaching target areas, while the wake has an important influence on trajectory stability and control accuracy. The present application superimposes a wake disturbance field in the target area to simulate the water flow changes caused by the target or surrounding structures, so that the simulated path can reflect the interference effect of the wake on the motion trajectory, which helps to evaluate the robustness of the path planning of offshore wind farm inspection ROVs in the near target area.

[0066] 3. With path disturbance analysis and visualization functions

[0067] The present application supports comparative analysis of paths under different flow fields, and can also be set to display the trajectory change trend in a graphical manner, facilitating user understanding of the influence of interference factors on the path. In addition, trajectory coordinate information and key interference sections can be exported according to actual needs, facilitating subsequent inspection ROV path optimization or use in conjunction with other planning algorithms.

[0068] 4. Wide applicability and simple deployment

[0069] The present application does not rely on dynamic or control models, but focuses on environmental disturbance modeling and trajectory response analysis, and is therefore suitable for early-stage task environment evaluation of inspection ROV path planning, with low deployment cost and gentle learning curve.

[0070] 5. Strong expandability

[0071] The present application not only can simulate and analyze the travel trajectory of a single ROV, but also can cooperate with multiple ROVs, perform linked analysis, and consider the influence of the wake of each ROV on other ROVs on the travel path. BRIEF DESCRIPTION OF DRAWINGS

[0072] Figure 1 Schematic diagram of the disturbance space distribution and its influence mechanism of the two stages of the ROV.

[0073] Figure 2 Schematic diagram of the ocean current vector in the Cartesian space coordinate system.

[0074] Figure 3 Schematic diagram of the wake vector in the ROV body coordinate system.

[0075] Figure 4 Schematic diagram of the three regions divided according to the influence of the wake.

[0076] Figure 5 Schematic diagram of the distribution of the wake. DETAILED DESCRIPTION

[0077] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, 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 some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0078] Embodiment 1

[0079] The thruster module serves as an actuator interface, which is responsible for converting the instructions of each thruster into a six-degree-of-freedom force / torque vector τ acting on the ROV. This module can calculate the resultant force and torque generated by all thrusters according to the thruster configuration model, taking into account their position, orientation, and operating characteristics. The output τ vector is then used by the dynamics module to update the motion dynamics of the ROV, thereby completing the simulation loop.

[0080] Firstly, the dynamics model of the ROV is established based on the Newton-Euler equation, which has the general form:

[0081]

[0082] where M represents the inertia matrix, including the mass inertia and added mass inertia, C(v) represents the Coriolis force and centrifugal force matrix, D(v) represents the damping matrix, represents the resistance encountered by the ROV during motion, G(η) represents the resultant force of gravity and buoyancy, τ represents the external input control torque, v represents the velocity vector, defined as: v = [u, v, w, p, q, r] T , u, v, w represent linear velocities, and p, q, r represent angular velocity components, denotes the derivative of the velocity vector v with respect to time;

[0083] The inertia matrix M = M R + M A is composed of two parts, M R represents the inertia term composed of the rigid body mass and the moment of inertia, and M A represents the fluid added mass matrix, which takes into account the inertial effects caused by the interaction between the robot and the water;

[0084]

[0085] The complete form is as follows: A body coordinate system is adopted, with its origin set at the center of mass (CoG) of the carrier, the x-axis pointing forward, the y-axis pointing to the right, and the z-axis pointing downward, following the standard right-hand coordinate system convention. Where m represents the mass, I z represents the moment of inertia about the z-axis, and I xdenotes the moment of inertia around the x-axis, I y denotes the moment of inertia around the y-axis, and denote the additional mass coefficients in the three degrees of freedom directions, respectively.

[0086] The Coriolis force and centrifugal force matrix C(v) is:

[0087]

[0088] The damping matrix D(v) reflects the damping effect of the water medium on the motion, which can be divided into two parts: linear damping D lin and nonlinear damping D nonlin (the quadratic term of velocity):

[0089] D lin = diag(X u ,Y v ,Z w ,K p ,M q ,N r )

[0090] D nonlin = diag(X |u| |u|,Y |v| |v|,Z |w| |w|,K |p| |p|,M |q| |q|,N |r| |r|)

[0091] D(v) = D lin + D nonlin

[0092] where X u , Y v , Z w denote the linear damping coefficients of the X, Y, Z axes, respectively, K p , M q , N r denote the linear damping coefficients in the rotation direction around the x, y, z three axes, respectively. The relevant parameters can be obtained through computational fluid dynamics (CFD) simulation or experimental calibration.

[0093] The gravity and buoyancy matrix G(η) represents the force / torque vector caused by gravity and buoyancy, which is a function of the attitude vector η, and reflects the restoring force caused by gravity and buoyancy under attitude change:

[0094]

[0095] where, θ represents the pitch angle, represents the rotation around the Y axis, φ represents the yaw angle, represents the rotation around the z axis, W represents the weight of the underwater vehicle, the unit is Newton, B represents the buoyancy acting on the vehicle, the unit is Newton; x g , y g , z g represent the coordinates of the center of mass in the body coordinate system, x b , y b , z b represent the coordinates of the center of buoyancy in the body coordinate system, η=[x,y,z,φ,θ,ψ] T , including the position and attitude of the vehicle in six degrees of freedom.

[0096] In order to establish the dynamic model of the remote control underwater robot, several simplifying assumptions and physical constraints are introduced in the embodiment. First, the remote control underwater robot is modeled as a rigid body, and its structural deformation in the motion process is ignored. Second, the surrounding fluid is assumed to be incompressible and uniform medium, so that the classical fluid dynamics theory can be applied. Third, the sea current is regarded as an external disturbance with constant speed, and its influence is taken into account in the path planning and control framework. Finally, in order to reduce the calculation complexity and focus on the core dynamic characteristics of the remote control underwater robot, the current model does not consider the internal disturbance caused by the propeller, including the influence of high-speed rotation of the propeller on the fluid environment.

[0097] Based on the above theory, the embodiment provides an ROV ocean current and wake flow interference analysis method for offshore wind farms, comprising the steps of,

[0098] S1, first, the complete motion trajectory of the ROV from the starting position 1 to the target position 2 is systematically analyzed, and the running process of the ROV is divided into a single ocean current interference region in the first stage (only large-scale background ocean current exists in this region, which has a continuous and stable disturbance force on the ROV) and an ocean current wake flow superimposed interference region 3 in the second stage (the region is simultaneously affected by the mixed region of background ocean current and wake flow), The mixed disturbance environment usually appears when approaching the structure such as obstacle, target or fixed platform, accompanied by complex hydrodynamic factors such as turbulence, vortex and local pressure gradient, which significantly changes the attitude response and trajectory planning strategy of the ROV. The schematic diagram of the disturbance space distribution and its influence mechanism of the above two stages is shown in Figure 1 .

[0099] Assuming that the ocean current is a one-way flow, the tidal current velocity vector at different depths in the shallow layer is calculated according to the tidal current velocity vector on the static water surface of the offshore wind farm, and the formula of the power law model is:

[0100]

[0101] Wherein, V c is the tidal current velocity vector on the static water surface, v c,tide (z) is the tidal current velocity vector at the depth of z, z is the distance above the static water surface, positive upward, d is the water depth, (positive value), e is the exponential, usually e = 1 / 7;

[0102] According to the tidal current velocity vector on the static water surface of the offshore wind farm, the wake velocity vector is calculated,

[0103] V f = V c (1-△) (2);

[0104] Wherein, V f is the wake velocity vector, △ is the wake velocity loss coefficient, which is used to describe the deceleration effect of the wake velocity compared with the free flow velocity, which mainly depends on the geometric configuration characteristics of the upstream obstacle and the flow field blockage rate, etc., the value range is determined according to the shape, size and flow direction angle of the obstacle, and changes in the range of 0.2 to 0.7.

[0105] S2, construct the ocean current three-dimensional vector model, decompose the ocean current direction in the Cartesian space coordinate system, assume that the overall direction of the ocean current vector in space can be represented by the angle β between it and the ZOX plane and the angle α between it and the XOY plane, as shown in Figure 2 , combined with the principle of spherical coordinate transformation, the projection velocity components of the tidal current velocity vector at different depths of the ocean current shallow layer in three principal axes are obtained, and the mathematical expression is:

[0106]

[0107] Wherein, V current is the component of simple ocean current velocity, v c,tide (z) is the tidal current velocity vector at the depth of z, β is the angle between the ocean current vector and the ZOX plane of the Cartesian space coordinate system, α is the angle between the ocean current vector and the XOY plane of the Cartesian space coordinate system, are respectively the projection velocity components of the tidal current velocity vector at different depths of the ocean current shallow layer in X axis, Y axis and Z axis.

[0108] S3, in the actual test, we found that the distribution of the wake area 7 is roughly as shown in Figure 5 , therefore, according to the influence of the wake, the operation area of the remotely operated vehicle ROV is divided into three areas, as shown in Figure 4 , which are respectively the wake-free area 4, the wake and ocean current direction consistent area 5 and the wake and ocean current direction opposite area 6.

[0109] S4, construct a two-dimensional vector model of the wake, as shown in Figure 3As shown, in the wake interference area, due to the significant angle between the flow direction of the wake and the main coordinate axis, it needs to be analyzed by vector decomposition. Figure 2 With Figure 3 the geometric structure, it can be determined that there is an angle β between the main flow direction of the wake and the X axis of the ROV body coordinate system, which is the angle between the current and the XOY plane (or the dual angle of the projection direction), the wake flow direction is decomposed in the local coordinate system, and the projection velocity components of the wake velocity vector in the X axis and Y axis directions are obtained, and the mathematical expression is:

[0110]

[0111] Among them, V wake is the component of the simple wake velocity, β is the angle between the wake vector and the X axis of the ROV body coordinate system, V final and V current are the projection velocity components of the wake velocity vector in the X axis and Y axis directions, respectively.

[0112] S5, analyze the superposition of the three areas of ocean current and wake, the wake-free area is not affected by the wake, the wake and the ocean current direction consistent influence area, the wake and the ocean current direction consistent, the wake velocity loss coefficient Δ=0.5, the wake and the ocean current direction opposite influence area, the wake and the ocean current direction opposite, the wake velocity loss coefficient Δ=0.3, combined with the projection velocity components of the tidal current velocity vector at different depths in the shallow layer of the ocean current and the projection velocity components of the wake velocity vector, the final velocity calculation relationship of the superposition of the ocean current and the wake in each influence area is constructed, wherein,

[0113] The final velocity calculation relationship of the superposition of the ocean current and the wake in the wake-free area is,

[0114] V final = V current (5);

[0115] Among them, V final is the final velocity of the superposition of the ocean current and the wake, and V current is the component of the simple ocean current velocity.

[0116] The final velocity calculation relationship of the superposition of the ocean current and the wake in the wake and ocean current direction consistent influence area is,

[0117]

[0118] Among them, V x , V y , and V z are the projection velocity components of the final velocity of the superposition of the ocean current and the wake in the X axis, Y axis, and Z axis, respectively. respectively are the projection velocity components of the tidal current velocity vector in the X axis, Y axis and Z axis respectively, respectively are the projection velocity components of the wake velocity vector in the X axis and Y axis respectively;

[0119] The final velocity calculation relationship of the superimposed ocean current and wake influence in the wake and ocean current direction opposite influence area is,

[0120]

[0121] S6, determine the heading according to the initial position and target position of the ROV, determine the influence area of the ROV according to the included angle between the heading and the sea current, and then calculate the final velocity of the superimposed ocean current and wake influence according to the corresponding final velocity calculation relationship of the superimposed ocean current and wake influence; The following operations are specifically performed:

[0122] Determine the heading of the ROV according to the initial position and target position of the ROV, that is, the direction of approaching the target, if the included angle ω between the direction of approaching the target of the ROV and the sea current is ω ∈ [-45°, +45°], the ROV is in the wake-free influence area, and then the final velocity of the superimposed ocean current and wake influence is calculated by formula (5);

[0123] If the included angle ω between the direction of approaching the target of the ROV and the sea current is ω ∈ (45°, 135°) ∪ (225°, -45°), the ROV is in the wake and ocean current direction consistent influence area, and then the final velocity of the superimposed ocean current and wake influence is calculated by formula (6);

[0124] If the included angle ω between the direction of approaching the target of the ROV and the sea current is ω ∈ [135°, 225°], the ROV is in the wake and ocean current direction opposite influence area, and then the final velocity of the superimposed ocean current and wake influence is calculated by formula (7).

[0125] S7, calculate the relative velocity component of the superimposed ocean current and wake influence according to the final velocity of the superimposed ocean current and wake influence, and update the relative velocity component in the damping matrix of the dynamic model of the ROV to the relative velocity component of the superimposed ocean current and wake influence, complete the analysis of the comprehensive influence of the ocean current and wake on the ROV path; The following operations are specifically performed:

[0126] Calculate the relative velocity component of the superimposed ocean current and wake influence according to the final velocity of the superimposed ocean current and wake influence and the relative velocity component in the damping matrix of the dynamic model of the ROV,

[0127]

[0128] Wherein, X u , Y v , Z wLinear damping coefficients of X, Y, Z axes in the damping matrix of the kinetic model of the ROV, respectively u1 v1 w1 Linear damping coefficients of X, Y, Z axes superimposed with the influence of ocean current and wake, respectively, v is a velocity vector, defined as: v = [u, v, w, p, q, r] T u, v, w are linear velocity components, and p, q, r are angular velocity components.

[0129] The relative velocity components in the damping matrix are updated to the relative velocity components superimposed with the influence of ocean current and wake, the analysis of the comprehensive influence of ocean current and wake on the ROV path is completed, and the damping matrix after updating the components is,

[0130]

[0131] K p M q N r Rotational damping coefficients around the angular velocity directions of X, Y, and Z axes, respectively.

[0132] This embodiment needs to perform at least two simulation analyses, the first segment is from the starting point to 2m away from the end point, only the influence of ocean current on the traveling direction of the ROV is considered, and the second segment is from the end point of the first segment simulation analysis to the final end point, and the comprehensive influence of ocean current and wake on the ROV path needs to be considered.

[0133] Embodiment 2:

[0134] The embodiment provides an ROV ocean current and wake interference analysis system for an offshore wind farm, which is used to implement the ROV ocean current and wake interference analysis method for the offshore wind farm in the embodiment 1, and includes,

[0135] An ocean current calculation module is configured to calculate the tidal current velocity vectors at different depths of the shallow layer of the ocean current according to the tidal current velocity vector on the static water surface of the offshore wind farm by using a power law model;

[0136] A wake calculation module is configured to calculate a wake velocity vector according to the tidal current velocity vector on the static water surface of the offshore wind farm;

[0137] An ocean current decomposition module is configured to construct an ocean current three-dimensional vector model, decompose the ocean current flow direction, and obtain the projection velocity components of the tidal current velocity vectors at different depths of the shallow layer of the ocean current in three main axis directions;

[0138] A region division module is configured to divide the operation region of the remotely operated vehicle (ROV) into a wake-free influence region, a wake and ocean current direction consistent influence region, and a wake and ocean current direction opposite influence region according to the influence of the wake; ​​

[0139] a wake flow decomposition module, configured to construct a two-dimensional vector model of the wake flow, decompose the wake flow direction, and obtain a projection velocity component of the wake velocity vector in the X-axis and Y-axis directions;

[0140] a relationship construction module, configured to construct a final velocity calculation relationship of the superimposed ocean current and wake flow influence in each influence area by combining the projection velocity components of the tidal velocity vector at different depths of the ocean current shallow layer and the projection velocity components of the wake velocity vector;

[0141] a final velocity calculation module, configured to determine a heading according to an initial position and a target position of the ROV, determine an influence area in which the ROV is located according to an included angle between the heading and the ocean current, and then calculate a final velocity of the superimposed ocean current and wake flow influence according to the corresponding final velocity calculation relationship of the superimposed ocean current and wake flow influence;

[0142] a damping matrix updating module, configured to calculate a relative velocity component of the superimposed ocean current and wake flow influence according to the final velocity of the superimposed ocean current and wake flow influence, and update the relative velocity component in a damping matrix of the dynamic model of the ROV to the relative velocity component of the superimposed ocean current and wake flow influence.

[0143] Embodiment 3

[0144] The embodiment provides a non-transitory computer readable medium storing instructions, when the instructions are executed by a processor, the method for analyzing ocean current and wake flow interference of an ROV of an offshore wind farm in embodiment 1 is executed.

[0145] The non-transitory computer readable medium in the embodiment can be a disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a U disk, a mobile hard disk, and the like.

[0146] Embodiment 4

[0147] The embodiment provides a computing device, including a processor and a memory for storing a program executable by the processor, when the processor executes the program stored in the memory, the method for analyzing ocean current and wake flow interference of an ROV of an offshore wind farm in embodiment 1 is implemented.

[0148] The computing device in the embodiment can be an embedded host, a desktop computer, a notebook computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal devices with processor functions.

[0149] The above merely describes preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent substitutions or changes within the scope disclosed by the present application, according to the technical solution and inventive concept of the present application, and such substitutions or changes shall also fall within the protection scope of the present application.

Claims

1. A method of ROV current and wake interference analysis for offshore wind farms, characterized in that, comprising the steps of According to the tidal current velocity vector on the static water surface of the offshore wind farm, the tidal current velocity vector at different depths of the ocean current shallow layer is calculated by using the power law model; and the wake velocity vector is calculated according to the tidal current velocity vector on the static water surface of the offshore wind farm; A three-dimensional vector model of the ocean current is constructed to decompose the flow direction of the ocean current, and the projection velocity components of the tidal current velocity vector at different depths of the ocean current shallow layer in three principal axis directions are obtained; According to the influence of the wake, the operation of the remotely operated vehicle (ROV) is divided into a wake-free influence area, a wake and ocean current direction consistent influence area, and a wake and ocean current direction opposite influence area; A two-dimensional vector model of the wake is constructed to decompose the flow direction of the wake, and the projection velocity components of the wake velocity vector in the X-axis and Y-axis directions are obtained; The projection velocity components of the tidal current velocity vector at different depths of the ocean current shallow layer and the projection velocity components of the wake velocity vector are combined to construct the final velocity calculation relationship of the superimposed ocean current and wake influence in each influence area; The heading of the ROV is determined according to the initial position and target position of the ROV, the influence area of the ROV is determined according to the included angle between the heading and the sea current, and then the final velocity of the superimposed ocean current and wake influence is calculated according to the corresponding final velocity calculation relationship of the superimposed ocean current and wake influence. The final velocity of the superimposed ocean current and wake influence is calculated according to the relative velocity component of the superimposed ocean current and wake influence, and the relative velocity component in the damping matrix of the dynamics model of the ROV is updated to the relative velocity component of the superimposed ocean current and wake influence, thereby completing the analysis of the comprehensive influence of the ocean current and wake on the ROV path.

2. A method of ROV current and wake interference analysis for offshore wind farms according to claim 1, characterized in that, According to the tidal current velocity vector on the static water surface of the offshore wind farm, the tidal current velocity vector at different depths of the ocean current shallow layer is calculated by using the power law model, where V c is the tidal current velocity vector on the water surface, v c,tide (z) is the tidal current velocity vector at depth z, z is the distance above the water surface, positive upwards, d is the water depth, and e is an exponent.

3. The method of ROV current and wake interference analysis for offshore wind farms according to claim 1, characterized in that, According to the tidal current velocity vector on the static water surface of the offshore wind farm, the tidal current velocity vector at different depths of the ocean current shallow layer is calculated by using the power law model, V f = V c (1 - Δ) (2); Where V c is the tidal current velocity vector on the water surface, V f is the wake velocity vector, and Δ is the wake velocity loss coefficient, the value range of which is determined according to the shape, size, and flow direction angle of the obstacle.

4. The method of ROV current and wake interference analysis for offshore wind farms of claim 1, wherein, A three-dimensional vector model of the ocean current is constructed to decompose the flow direction of the ocean current in the Cartesian space coordinate system, and the projection velocity components of the tidal current velocity vector at different depths of the ocean current shallow layer in three principal axis directions are obtained, and the mathematical expression is: where V current is the component of the simple current velocity, v c,tide (z) is the tidal current velocity vector at depth z, β is the angle between the current vector and the ZOX plane of the Cartesian coordinate system, and α is the angle between the current vector and the XOY plane of the Cartesian coordinate system, are the projection velocity components of the tidal current velocity vector at different depths in the shallow layer of the current on the X-axis, Y-axis, and Z-axis, respectively.

5. The method of ROV current and wake interference analysis for offshore wind farms according to claim 1, characterized in that, A two-dimensional vector model of the wake is constructed to decompose the flow direction of the wake in the local coordinate system, and the projection velocity components of the wake velocity vector in the X-axis and Y-axis directions are obtained, and the mathematical expression is: where V wake is the component of the simple wake velocity, β is the angle between the wake vector and the X-axis of the body coordinate system of the ROV, are the projection velocity components of the wake velocity vector in the X-axis and Y-axis directions, respectively.

6. The method of ROV current and wake interference analysis for offshore wind farms of claim 1, wherein, The wake-free influence area is not affected by the wake, the wake and ocean current direction consistent influence area is consistent with the direction of the ocean current, the wake velocity loss coefficient Δ = 0.5, and the wake and ocean current direction opposite influence area is opposite to the direction of the ocean current, the wake velocity loss coefficient Δ = 0.

3.

7. The method of ROV current and wake interference analysis for offshore wind farms according to claim 1, characterized in that, The final velocity calculation relationship of the superimposed ocean current and wake influence in the wake-free influence area is V final = V current (5); where V final is the final velocity with the superimposed current and wake effects, V current is the component of the pure current velocity; The final velocity calculation relationship of the superimposed ocean current and wake influence in the wake and ocean current direction consistent influence area is wherein Vx, Vy, Vz are the velocity components of the final velocity in the X, Y, Z axes, respectively, x , Vy, Vz are the velocity components of the tidal current velocity vector in the X, Y, Z axes, respectively, y , Vy, Vz are the velocity components of the wake velocity vector in the X, Y, Z axes, respectively, z , Vy, Vz are the velocity components of the final velocity in the X, Y, Z axes, respectively, , Vy, Vz are the velocity components of the tidal current velocity vector in the X, Y, Z axes, respectively, , Vy, Vz are the velocity components of the wake velocity vector in the X, Y, Z axes, respectively, The final velocity calculation relationship of the superimposed ocean current and wake influence in the wake and ocean current direction opposite influence area is 8. A method of ROV current and wake interference analysis for offshore wind farms according to claim 7, characterized in that, The heading of the ROV is determined according to the initial position and target position of the ROV, the influence area of the ROV is determined according to the included angle between the heading and the sea current, and then the final velocity of the superimposed ocean current and wake influence is calculated according to the corresponding final velocity calculation relationship of the superimposed ocean current and wake influence. The final velocity of the superimposed ocean current and wake influence is calculated according to the relative velocity component of the superimposed ocean current and wake influence, and the relative velocity component in the damping matrix of the dynamics model of the ROV is updated to the relative velocity component of the superimposed ocean current and wake influence, thereby completing the analysis of the comprehensive influence of the ocean current and wake on the ROV path. If the included angle ω between the direction of the ROV approaching the target and the ocean current is ω ∈ (45°, 135°) ∪ (225°, -45°), the ROV is in the area where the wake and the ocean current are in the same direction, and then the final speed of the superposition of the ocean current and the wake is calculated by using formula (6); If the included angle ω between the direction of the ROV approaching the target and the ocean current is ω ∈ [135°, 225°], the ROV is in the area where the wake and the ocean current are in opposite directions, and then the final speed of the superposition of the ocean current and the wake is calculated by using formula (7).

9. The method of ROV current and wake interference analysis for offshore wind farms of claim 1, wherein, According to the final speed of the superposition of the ocean current and the wake and the relative speed component in the damping matrix of the dynamic model of the ROV, the relative speed component of the superposition of the ocean current and the wake is calculated, wherein X u , Y v , Z w are linear damping coefficients of X, Y, Z axes in the damping matrix of the dynamic model of the ROV, D u1 , D v1 , D w1 are linear damping coefficients of X, Y, Z axes superimposed with the influence of ocean current and wake, v is a velocity vector, defined as: v = [u, v, w, p, q, r] T , u, v, w are linear velocity components, and p, q, r are angular velocity components; The relative speed component in the damping matrix is updated to the relative speed component of the superposition of the ocean current and the wake, the analysis of the comprehensive influence of the ocean current and the wake on the ROV path is completed, and the damping matrix after the component is updated is where K p , M q , N r are the rotational damping coefficients in the direction of the angular velocity around the X, Y, Z axes, respectively.

10. A ROV current and wake interference analysis system for an offshore wind farm, characterized in that, The ROV ocean current and wake interference analysis method for the offshore wind farm of any one of claims 1-9 is used to realize, The ocean current calculation module is used to calculate the tidal current velocity vector at different depths of the ocean current shallow layer according to the tidal current velocity vector on the static water surface of the offshore wind farm by using a power law model; The wake calculation module is used to calculate the wake velocity vector according to the tidal current velocity vector on the static water surface of the offshore wind farm; The ocean current decomposition module is used to construct an ocean current three-dimensional vector model, decompose the ocean current flow direction, and obtain the projection speed components of the tidal current velocity vector at different depths of the ocean current shallow layer in three principal axis directions; The area division module is used to divide the operation area of the remotely operated vehicle (ROV) into a wake-free influence area, a wake and ocean current consistent influence area, and a wake and ocean current opposite influence area according to the influence of the wake; The wake decomposition module is used to construct a wake two-dimensional vector model, decompose the wake flow direction, and obtain the projection speed components of the wake velocity vector in the X-axis and Y-axis directions; The relationship construction module is used to construct the final speed calculation relationship of the superposition of the ocean current and the wake in each influence area in combination with the projection speed components of the tidal current velocity vector at different depths of the ocean current shallow layer and the projection speed components of the wake velocity vector; The final speed calculation module is used to determine the heading according to the initial position and the target position of the ROV, determine the influence area of the ROV according to the included angle between the heading and the ocean current, and then calculate the final speed of the superposition of the ocean current and the wake according to the corresponding final speed calculation relationship of the superposition of the ocean current and the wake. The damping matrix updating module is used to calculate the relative speed component of the superposition of the ocean current and the wake according to the final speed of the superposition of the ocean current and the wake, and update the relative speed component in the damping matrix of the dynamic model of the ROV to the relative speed component of the superposition of the ocean current and the wake.

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