ROV ocean current and wake interference analysis method and system for offshore wind plant

Abstract

The invention discloses an ROV ocean current and wake flow interference analysis method and system for an offshore wind plant, and the method comprises the steps: calculating tidal current velocity vectors of different depths of an ocean current shallow layer, and calculating a wake flow velocity vector; obtaining projection velocity components of tidal current velocity vectors of different depths of the ocean current shallow layer; the operation of the ROV is divided into a wake flow-free influence area, a wake flow and ocean current direction consistent influence area and a wake flow and ocean current direction opposite influence area; obtaining a projection velocity component of the wake flow velocity vector; according to the projection velocity component, constructing a final velocity calculation relational expression of the superposed ocean current and wake flow influence; calculating the final speed of the superposed ocean current and wake flow influence; and calculating the relative velocity component of the superposed ocean current and wake flow influence, and updating the relative velocity component in the damping matrix of the dynamical model of the ROV into the relative velocity component of the superposed ocean current and wake flow influence. According to the method, the problems of insufficient ocean current modeling dimension, no consideration of wake flow disturbance, weak path interference analysis capability and the like in offshore wind plant inspection ROV path interference analysis are effectively solved.

Description

Technical Field

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

[0002] Remotely operated underwater vehicles (ROVs) play an important role in the inspection of offshore wind farms. They can penetrate deep underwater to conduct comprehensive inspections of the wind farm's underwater infrastructure (such as monopile foundations, gravity foundations, etc.). At the same time, they can also inspect the laying of underwater cables to check for problems such as wear, breakage, and entanglement with foreign objects. Compared with traditional manual diving inspection methods, ROVs have the advantages of high operating efficiency, good safety, and long-term continuous operation. They can quickly and accurately obtain detailed information on underwater facilities, providing reliable data support for wind farm operation and maintenance personnel, allowing them to promptly identify potential hidden dangers and take measures to repair them, ensuring the safe and stable operation of offshore wind farms, reducing operation and maintenance costs, and improving the overall operational efficiency of wind farms.

[0003] ROV path planning and motion control are core technologies for mission success. Due to the prevalence of uncertainties in underwater environments, such as complex currents, irregularly distributed obstacles, and dynamic target changes, path planning requires strong environmental perception, interference immunity, and dynamic adjustment capabilities. Therefore, researchers often utilize simulation analysis systems to perform path interference analysis before deployment to reduce risks and costs in actual operations.

[0004] Current path interference analysis mainly suffers from the following common technical bottlenecks:

[0005] 1. Unable to simulate three-dimensional non-uniform ocean current environments. Most systems only support two-dimensional or simplified steady-state flow models, making it difficult to accurately reflect the three-dimensional ocean current characteristics that vary with depth and region in the real ocean.

[0006] 2. Ignoring the wake disturbance effect, that is, when the ROV approaches the target area, the wake disturbance caused by the target object or surrounding structures is not considered, which causes the trajectory simulation results to deviate from the actual results;

[0007] 3. The lack of visualization and data output capabilities for trajectory disturbances makes it difficult to assist users in pre-assessing specific operating areas or performing path adjustment analysis;

[0008] In summary, existing technologies have not yet achieved a joint modeling and analysis path feedback mechanism for three-dimensional ocean current disturbances and target wake effects, which limits the path planning accuracy of offshore wind farm inspection ROVs and the engineering reference value of analysis results in complex underwater environments. Summary of the Invention

[0009] The first purpose of the present invention is to overcome the shortcomings of the existing technology 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, failure to consider wake disturbances, and weak path interference analysis capabilities in the path interference analysis of remote-controlled underwater robots for offshore wind farm inspections.

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

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

[0012] A fourth object of the present invention is to provide a computing device.

[0013] The first object of the present invention is achieved through the following technical solutions:

[0014] A method for analyzing ROV ocean current and wake interference for offshore wind farms, comprising the steps of:

[0015] The tidal velocity vectors at different depths in the shallow layer of the ocean current are calculated using a power law model based on the tidal velocity vectors on the still water surface of the offshore wind farm; the wake velocity vectors are calculated based on the tidal velocity vectors on the still water surface of the offshore wind farm;

[0016] Construct a three-dimensional vector model of ocean currents, decompose the current direction, and obtain the projected velocity components of the tidal velocity vector at different depths in the shallow layer of the ocean current in the three main axis directions;

[0017] According to the influence of wake, the operation of remote-controlled underwater robot (ROV) is divided into the area without wake influence, the area with wake influence in the same direction as the ocean current, and the area with wake influence in the opposite direction of the ocean current.

[0018] Construct a two-dimensional wake vector model, decompose the wake flow direction, and obtain the projected velocity components of the wake velocity vector in the X-axis and Y-axis directions;

[0019] Combining the projected velocity components of the tidal velocity vector and the projected velocity components of the wake velocity vector at different depths in the shallow layer of the ocean current, the final velocity calculation relationship of the superimposed ocean current and wake influence in each affected area is constructed respectively;

[0020] The heading is determined based on the initial position and target position of the ROV, the impact area of ​​the ROV is determined based on the angle between the heading and the ocean current, and the final velocity of the superimposed ocean current and wake is calculated based on the corresponding final velocity calculation relationship of the superimposed ocean current and wake;

[0021] The relative velocity component of the superimposed ocean current and wake is calculated based on the final velocity of the superimposed ocean current and wake, and the relative velocity component in the damping matrix of the ROV's dynamic model is updated to the relative velocity component of the superimposed ocean current and wake, completing the analysis of the comprehensive impact of the ocean current and wake on the ROV path.

[0022] Furthermore, the power law model is used to calculate the tidal velocity vectors at different depths in the shallow layer of the ocean current based on the tidal velocity vectors on the still water surface.

[0023]

[0024] Among them, V c is the tidal velocity vector on the still water surface, v c,tide (z) is the tidal velocity vector at depth z, z is the distance above the still water surface, positive is upward, d is the water depth, and e is the exponent.

[0025] Furthermore, the wake velocity vector is calculated based on the tidal velocity vector on the still water surface.

[0026] V f =V c (1-△) (2);

[0027] Among them, V c is the tidal velocity vector on the still water surface, V f is the wake velocity vector, △ is the wake velocity loss coefficient, and its value range is determined according to the shape, size, flow direction and angle of attack of the obstacle.

[0028] Furthermore, a three-dimensional vector model of ocean currents is constructed, and the direction of the ocean currents is decomposed in the Cartesian space coordinate system to obtain the projection velocity components of the tidal velocity vectors at different depths in the shallow layer of the ocean currents in the three main axis directions. The mathematical expression is:

[0029]

[0030] Among them, V current is the component of pure ocean current velocity, v c,tide (z) is the tidal velocity vector at depth 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, They are the projection velocity components of the tidal velocity vector at different depths in the shallow layer of the ocean current on the X-axis, Y-axis, and Z-axis respectively.

[0031] Furthermore, a two-dimensional wake vector model is constructed, and the wake flow direction is decomposed in the local coordinate system to obtain the projected velocity components of the wake velocity vector in the X-axis and Y-axis directions. The mathematical expression is:

[0032]

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

[0034] Furthermore, the wake-free area is not affected by the wake, the wake in the area with the same direction as the ocean current is consistent, and the wake velocity loss coefficient △=0.5. The wake in the area with the opposite direction to the ocean current is opposite to the ocean current, and the wake velocity loss coefficient △=0.3.

[0035] Furthermore, the final velocity calculation relationship between the superimposed ocean current and the wake in the area without wake influence is: V final =V current (5);

[0036] Among them, V final V is the final velocity of the superimposed ocean current and wake, current is the component of pure ocean current velocity;

[0037] The final velocity calculation relationship of the superimposed ocean current and wake in the area of ​​influence with the same direction of wake and ocean current is:

[0038]

[0039] Among them, V x 、V y 、V z are the projected velocity components of the final velocity affected by the superimposed ocean current and wake on the X-axis, Y-axis, and Z-axis, respectively. are the projection velocity components of the tidal velocity vector at different depths in the shallow layer of the ocean current on the X-axis, Y-axis, and Z-axis, respectively. are the projected velocity components of the wake velocity vector in the X-axis and Y-axis directions respectively;

[0040] The final velocity calculation relationship of the superposition of the ocean current and the wake in the area with opposite influence directions is:

[0041]

[0042] Furthermore, the heading of the ROV is determined according to its initial position and target position, that is, the direction of approaching the target. If the angle ω∈[-45°, +45°] between the direction of the ROV approaching the target and the ocean current, the ROV is in the area without wake influence, and then the final velocity under the influence of the superimposed ocean current and wake is calculated using formula (5);

[0043] If the angle ω between the direction of the ROV approaching the target and the ocean current is (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 velocity affected by the superimposed ocean current and wake is calculated using formula (6);

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

[0045] Furthermore, the relative velocity component of the superimposed ocean current and wake is calculated based on the final velocity of the superimposed ocean current and wake and the relative velocity component in the damping matrix of the ROV dynamic model.

[0046]

[0047] Among them, X u 、Y v 、Z w are the linear damping coefficients of the X, Y, and Z axes in the damping matrix of the ROV dynamic model, D u1 、D v1 、D w1 are the linear damping coefficients of the X, Y, and Z axes due to the influence of the superimposed ocean current and wake, respectively. v is the velocity vector, defined as: v = [u, v, w, p, q, r] T , u, v, w are linear velocity components, p, q, r are angular velocity components;

[0048] Update the relative velocity component in the damping matrix to the relative velocity component with the superimposed ocean current and wake effects, and complete the analysis of the comprehensive impact of ocean current and wake on the ROV path. The damping matrix after the updated components is:

[0049]

[0050] Among them, K p 、M q 、N r are the rotational damping coefficients in the angular velocity directions around the X, Y, and Z axes, respectively.

[0051] The second object of the present invention is achieved by the following technical solutions:

[0052] An ROV ocean current and wake interference analysis system for offshore wind farms, used to implement the above-mentioned ROV ocean current and wake interference analysis method for offshore wind farms, comprising:

[0053] The ocean current calculation module is used to calculate the tidal velocity vectors at different depths in the shallow layer of the ocean current using a power law model based on the tidal velocity vectors on the still water surface of the offshore wind farm;

[0054] A wake calculation module is used to calculate the wake velocity vector based on the tidal velocity vector on the still water surface of the offshore wind farm;

[0055] The ocean current decomposition module is used to construct a three-dimensional vector model of ocean currents, decompose the direction of ocean currents, and obtain the projected velocity components of the tidal velocity vectors at different depths in the shallow layer of the ocean currents in the three main axis directions;

[0056] The area division module is used to divide the operating area of ​​the remote-controlled underwater robot ROV into an area without wake influence, an area with wake influence in the same direction as the ocean current, and an area with wake influence in the opposite direction to the ocean current according to the influence of the wake;

[0057] The wake decomposition module is used to construct a two-dimensional wake vector model, decompose the wake flow direction, and obtain the projected velocity components of the wake velocity vector in the X-axis and Y-axis directions;

[0058] A relationship building module is used to combine the projected velocity components of the tidal velocity vector and the projected velocity components of the wake velocity vector at different depths in the shallow layer of the ocean current to respectively build a final velocity calculation relationship for the superimposed ocean current and wake influence in each affected area;

[0059] The final velocity calculation module is used to determine the heading according to the initial position and target position of the ROV, determine the affected area of ​​the ROV according to the angle between the heading and the ocean current, and then calculate the final velocity of the superimposed ocean current and wake according to the corresponding final velocity calculation relationship of the superimposed ocean current and wake;

[0060] The damping matrix update module is used to calculate the relative velocity component affected by the superimposed ocean current and wake according to the final velocity affected by the superimposed ocean current and wake, and update the relative velocity component in the damping matrix of the ROV dynamic model to the relative velocity component affected by the superimposed ocean current and wake.

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

[0062] 1. This invention supports three-dimensional complex ocean current environment modeling

[0063] Traditional ROV path interference analysis mostly uses a two-dimensional constant flow model, which is difficult to simulate the spatially varying three-dimensional ocean current structure in real waters. This invention introduces a configurable three-dimensional velocity field, allowing users to define the velocity and direction of ocean currents in different spatial regions. This improves the model's ability to represent heterogeneous environments and provides more realistic simulation conditions for offshore wind farm inspection ROV path assessment.

[0064] 2. Introducing wake interference modeling mechanism

[0065] Existing path interference analyses generally ignore the wake disturbances faced by remote-controlled underwater vehicles (ROVs) as they approach a target area, which significantly impacts trajectory stability and control accuracy. This new method superimposes a wake disturbance field over the target area to simulate the water flow changes caused by the target or surrounding structures. This allows the simulated path to reflect the effect of the wake on the motion trajectory, helping to evaluate the robustness of path planning for offshore wind farm inspection ROVs near the target area.

[0066] 3. Path interference analysis and visualization capabilities

[0067] This method supports comparative analysis of paths under different flow field settings and can be configured to graphically display trajectory trends, helping users understand the impact of interference factors on the path. Furthermore, trajectory coordinate information and key interference sections can be exported based on actual needs, facilitating subsequent inspection ROV path optimization or integration with other planning algorithms.

[0068] 4. Wide applicability and easy deployment

[0069] The present invention does not rely on dynamics or control models, but focuses on environmental interference modeling and trajectory response analysis. Therefore, it is suitable for mission environment assessment in the early stage of inspection ROV path planning, with low deployment cost and a flat learning curve.

[0070] 5. Strong scalability

[0071] The present invention can not only simulate and analyze the trajectory of a single ROV, but also cooperate with multiple ROVs to conduct linkage analysis and consider the impact of the wake of each ROV on other ROVs on the travel path. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 Schematic diagram of the spatial distribution of disturbances and their impact mechanisms in the two stages of ROV.

[0073] Figure 2 Schematic diagram of ocean current vector in 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 wake.

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

[0077] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0078] Example 1:

[0079] The thruster module serves as the actuator interface, converting commands from individual thrusters into a six-degree-of-freedom (DOF) force / torque vector τ acting on the remotely operated underwater vehicle (ROV). Based on the thruster configuration model, this module calculates the resulting force and torque generated by all thrusters, taking into account their position, orientation, and operating characteristics. The output τ vector is then used by the dynamics module to update the ROV's kinematic dynamics, completing the simulation loop.

[0080] First, the dynamic model of ROV is established based on the Newton-Euler equation, and its general form is:

[0081]

[0082] Where M is the inertia matrix, including the inertia of its own mass and the inertia of the added mass, C(v) is the Coriolis force and centrifugal force matrix, D(ν) is the damping matrix, which represents the resistance encountered by the remote-controlled underwater robot (ROV) during movement, G(η) is the resultant force of gravity and buoyancy, τ is the external input control torque, and v is the velocity vector, which is defined as: v = [u, v, w, p, q, r] T , u, v, w represent linear velocity, p, q, r represent angular velocity components, represents the time derivative of the velocity vector ν;

[0083] Inertia matrix M = M R +M A It consists of two parts, M R Represents the inertia term consisting of the rigid body mass and rotational inertia, M A represents the fluid added mass matrix, which takes into account the inertial effect caused by the interaction between the robot and the water body;

[0084]

[0085] The complete form is as follows: A body coordinate system is used, with its origin set at the center of mass (CoG) of the carrier, the x-axis facing forward, the y-axis facing starboard, and the z-axis facing downward, following the standard right-hand coordinate system convention. z represents the moment of inertia around the z-axis, I xrepresents the moment of inertia around the x-axis, I y represents the moment of inertia around the y-axis, and Represent the additional mass coefficients in the three degrees of freedom directions respectively.

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

[0087]

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

[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] Among them, X u ,Y v ,Z w Represents the linear damping coefficients of the X, Y, and Z axes, K p ,M q ,N r The linear damping coefficients in the rotational directions around the x, y, and z axes are 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. It is a function of the attitude vector η and reflects the restoring force caused by gravity and buoyancy under attitude changes:

[0094]

[0095] Where θ is the pitch angle, which represents the rotation around the Y axis; φ is the yaw angle, which represents the rotation around the z axis; W is the weight of the underwater vehicle, in Newtons; B is the buoyancy acting on the vehicle, in Newtons; x g 、y g 、z g Represents the coordinates of the center of mass in the body coordinate system, x b 、y b 、z b represents 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 spacecraft in six degrees of freedom.

[0096] To facilitate the establishment of a dynamic model for a remote-controlled underwater robot, this embodiment introduces several simplifying assumptions and physical constraints. First, the remote-controlled underwater robot is modeled as a rigid body, and its structural deformation during motion is ignored. Second, the surrounding fluid is assumed to be an incompressible and uniform medium, so that classical fluid dynamics theory can be applied. Third, the ocean current is regarded as an external disturbance with a constant speed, and its influence is incorporated into the path planning and control framework. Finally, to reduce computational complexity and focus on the core dynamic characteristics of the remote-controlled underwater robot, the current model does not consider the internal disturbance caused by the propeller, including the impact of the high-speed rotation of the propeller on the fluid environment.

[0097] Based on the above theory, this embodiment provides an ROV ocean current and wake interference analysis method for offshore wind farms, including the following steps:

[0098] S1. First, a systematic analysis is conducted on the complete motion trajectory of the ROV from the starting position 1 to the target position 2. According to the spatial distribution of the actual hydrodynamic interference of the offshore wind farm, the operation process of the ROV is divided into the first stage of the single ocean current interference area (in this area, there are only large-scale background ocean currents, which produce continuous and stable disturbance force on the ROV) and the second stage of the ocean current wake superposition interference area 3 (this area is controlled by the mixed area of ​​the background ocean current and the wake flow at the same time). This mixed disturbance environment usually occurs when approaching obstacles, targets or fixed platforms and other structures, accompanied by complex hydrodynamic factors such as turbulence, vortices and local pressure gradients, which significantly change the attitude response and trajectory planning strategy of the ROV. The schematic diagram of the spatial distribution of disturbances and their influencing mechanisms in the above two stages is shown as follows: Figure 1 shown.

[0099] Assuming that the ocean current is unidirectional, the power law model is used to calculate the tidal velocity vector at different depths in the shallow layer of the ocean current based on the tidal velocity vector on the still water surface of the offshore wind farm. The formula of the power law model is:

[0100]

[0101] Among them, V c is the tidal velocity vector on the still water surface, v c,tide (z) is the tidal velocity vector at depth z, z is the distance above the still water surface, positive upward, d is the water depth (takes a positive value), and e is the exponent, usually e = 1 / 7;

[0102] The wake velocity vector is calculated based on the tidal velocity vector on the still water surface of the offshore wind farm.

[0103] V f =V c (1-△) (2);

[0104] Among them, V f is the wake velocity vector, △ is the wake velocity loss coefficient, which is used to characterize the deceleration effect of the wake velocity compared to the free stream velocity. This parameter mainly depends on factors such as the geometric configuration characteristics of the upstream obstacle and the flow field blockage rate. The value range is determined by the shape, size, and flow direction angle of attack of the obstacle, and varies from 0.2 to 0.7.

[0105] S2. Construct a three-dimensional vector model of ocean currents and decompose the direction of ocean currents in the Cartesian 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 follows: Figure 2 As shown in the figure, combined with the principle of spherical coordinate transformation, the projection velocity components of the tidal velocity vector at different depths in the shallow layer of the ocean current in the three main axis directions are obtained, and its mathematical expression is:

[0106]

[0107] Among them, V current is the component of pure ocean current velocity, v c,tide (z) is the tidal velocity vector at depth 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, They are the projection velocity components of the tidal velocity vector at different depths in the shallow layer of the ocean current on the X-axis, Y-axis, and Z-axis respectively.

[0108] S3. In actual tests, we found that the distribution of the wake area 7 is roughly as follows Figure 5 As shown, the operating area of ​​the remote control underwater robot ROV is divided into three areas according to the influence of the wake, as shown in Figure 4 As shown, there is no wake influence area 4, the wake influence area 5 is consistent with the direction of the ocean current, and the wake influence area 6 is opposite to the direction of the ocean current.

[0109] S4, construct a two-dimensional vector model of the wake, such as Figure 3As shown in the figure, in the wake interference area, due to the significant angle between the flow direction of the wake and the main coordinate axis, it is necessary to perform vector decomposition analysis on it. Figure 2 and Figure 3 From the geometric structure of the wake, it can be clearly seen that there is an angle β between the main direction of the wake and the X-axis of the ROV body coordinate system. This angle is the angle between the ocean current and the XOY plane (or the dual angle of its projection direction). The wake direction is decomposed in the local coordinate system to obtain the projection velocity components of the wake velocity vector in the X-axis and Y-axis directions. Its mathematical expression is:

[0110]

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

[0112] S5. Analyze the superimposed influence of ocean currents and wakes in the three regions. The area without wake influence is not affected by wakes. The direction of the wake is consistent with that of the ocean current in the influence region, and the wake velocity loss coefficient is △=0.5. The direction of the wake is opposite to that of the ocean current in the influence region, and the wake velocity loss coefficient is △=0.3. Combine the projection velocity components of the tidal velocity vector at different depths in the shallow layer of the ocean current and the projection velocity components of the wake velocity vector to construct the final velocity calculation relationship of the superimposed ocean current and wake influence in each influence region, where:

[0113] The calculation relationship between the final velocity of the superimposed ocean current and the wake in the area without wake influence is:

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

[0115] Among them, V final V is the final velocity of the superimposed ocean current and wake, current is the component of pure ocean current velocity;

[0116] The final velocity calculation relationship of the superimposed ocean current and wake in the area of ​​influence with the same direction of wake and ocean current is:

[0117]

[0118] Among them, V x 、V y 、V z are the projected velocity components of the final velocity affected by the superimposed ocean current and wake on the X-axis, Y-axis, and Z-axis, respectively. are the projection velocity components of the tidal velocity vector at different depths in the shallow layer of the ocean current on the X-axis, Y-axis, and Z-axis, respectively. are the projected velocity components of the wake velocity vector in the X-axis and Y-axis directions respectively;

[0119] The final velocity calculation relationship of the superposition of the ocean current and the wake in the area with opposite influence directions is:

[0120]

[0121] S6. Determine the heading based on the initial position and target position of the ROV, determine the affected area of ​​the ROV based on the angle between the heading and the ocean current, and then calculate the final velocity of the superimposed ocean current and wake based on the corresponding final velocity calculation relationship of the superimposed ocean current and wake. Specifically, perform the following operations:

[0122] According to the initial position and target position of the ROV, its heading, that is, the direction of approaching the target, is determined. If the angle ω∈[-45°, +45°] between the direction of the ROV approaching the target and the ocean current, the ROV is in the area without wake influence, and then the final velocity under the influence of the superimposed ocean current and wake is calculated using formula (5);

[0123] If the angle ω between the direction of the ROV approaching the target and the ocean current is (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 velocity affected by the superimposed ocean current and wake is calculated using formula (6);

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

[0125] S7. Calculate the relative velocity component of the superimposed ocean current and wake based on the final velocity of the superimposed ocean current and wake, and update the relative velocity component in the damping matrix of the ROV's dynamic model to the relative velocity component of the superimposed ocean current and wake, completing the analysis of the comprehensive impact of the ocean current and wake on the ROV path. Specifically, perform the following operations:

[0126] The relative velocity components of the superimposed ocean current and wake are calculated based on the final velocity of the superimposed ocean current and wake and the relative velocity components in the damping matrix of the ROV's dynamic model.

[0127]

[0128] Among them, X u 、Y v 、Z ware the linear damping coefficients of the X, Y, and Z axes in the damping matrix of the ROV dynamic model, D u1 、D v1 、D w1 are the linear damping coefficients of the X, Y, and Z axes due to the influence of the superimposed ocean current and wake, respectively. v is the velocity vector, defined as: v = [u, v, w, p, q, r] T , u, v, w are linear velocity components, p, q, r are angular velocity components;

[0129] Update the relative velocity component in the damping matrix to the relative velocity component with the superimposed ocean current and wake effects, and complete the analysis of the comprehensive impact of ocean current and wake on the ROV path. The damping matrix after the updated components is:

[0130]

[0131] Among them, K p 、M q 、N r are the rotational damping coefficients in the angular velocity directions around the X, Y, and Z axes, respectively.

[0132] This embodiment requires at least two sections of simulation analysis. The first section is from the starting point to 2 meters away from the end point. This section only considers the impact of ocean currents on the ROV's direction of travel. The second section starts from the end point of the first simulation analysis and ends at the final end point. This section requires a classified discussion to consider the combined impact of ocean currents and wakes on the ROV's path.

[0133] Example 2:

[0134] This 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 an offshore wind farm described in Example 1, including:

[0135] The ocean current calculation module is used to calculate the tidal velocity vectors at different depths in the shallow layer of the ocean current using a power law model based on the tidal velocity vectors on the still water surface of the offshore wind farm;

[0136] A wake calculation module is used to calculate the wake velocity vector based on the tidal velocity vector on the still water surface of the offshore wind farm;

[0137] The ocean current decomposition module is used to construct a three-dimensional vector model of ocean currents, decompose the direction of ocean currents, and obtain the projected velocity components of the tidal velocity vectors at different depths in the shallow layer of the ocean currents in the three main axis directions;

[0138] The area division module is used to divide the operating area of ​​the remote-controlled underwater robot ROV into an area without wake influence, an area with wake influence in the same direction as the ocean current, and an area with wake influence in the opposite direction to the ocean current according to the influence of the wake;

[0139] The wake decomposition module is used to construct a two-dimensional wake vector model, decompose the wake flow direction, and obtain the projected velocity components of the wake velocity vector in the X-axis and Y-axis directions;

[0140] A relationship building module is used to combine the projected velocity components of the tidal velocity vector and the projected velocity components of the wake velocity vector at different depths in the shallow layer of the ocean current to respectively build a final velocity calculation relationship for the superimposed ocean current and wake influence in each affected area;

[0141] The final velocity calculation module is used to determine the heading according to the initial position and target position of the ROV, determine the affected area of ​​the ROV according to the angle between the heading and the ocean current, and then calculate the final velocity of the superimposed ocean current and wake according to the corresponding final velocity calculation relationship of the superimposed ocean current and wake;

[0142] The damping matrix update module is used to calculate the relative velocity component affected by the superimposed ocean current and wake according to the final velocity affected by the superimposed ocean current and wake, and update the relative velocity component in the damping matrix of the ROV dynamic model to the relative velocity component affected by the superimposed ocean current and wake.

[0143] Example 3

[0144] This embodiment provides a non-transitory computer-readable medium storing instructions. When the instructions are executed by a processor, the ROV ocean current and wake interference analysis method for an offshore wind farm described in Example 1 is executed.

[0145] The non-transitory computer-readable medium in this embodiment can be a disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a USB flash drive, a mobile hard disk, or other media.

[0146] Example 4

[0147] This 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 ROV current and wake interference analysis method for offshore wind farms described in Example 1 is implemented.

[0148] The computing device described in this embodiment may be an embedded host, a desktop computer, a laptop computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal devices with a processor function.

[0149] The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes based on the technical solution and invention concept of the present invention within the scope disclosed by the present invention, which falls within the scope of protection of the present invention.

Claims

1. A method for analyzing ROV ocean current and wake interference for offshore wind farms, characterized in that: Including steps, The tidal velocity vectors at different depths in the shallow layer of the ocean current are calculated using a power law model based on the tidal velocity vectors on the still water surface of the offshore wind farm; the wake velocity vectors are calculated based on the tidal velocity vectors on the still water surface of the offshore wind farm; Construct a three-dimensional vector model of ocean currents, decompose the current direction, and obtain the projected velocity components of the tidal velocity vector at different depths in the shallow layer of the ocean current in the three main axis directions; According to the influence of wake, the operation of remote-controlled underwater robot (ROV) is divided into the area without wake influence, the area with wake influence in the same direction as the ocean current, and the area with wake influence in the opposite direction of the ocean current. Construct a two-dimensional wake vector model, decompose the wake flow direction, and obtain the projected velocity components of the wake velocity vector in the X-axis and Y-axis directions; Combining the projected velocity components of the tidal velocity vector and the projected velocity components of the wake velocity vector at different depths in the shallow layer of the ocean current, the final velocity calculation relationship of the superimposed ocean current and wake influence in each affected area is constructed respectively; The heading is determined based on the initial position and target position of the ROV, the impact area of ​​the ROV is determined based on the angle between the heading and the ocean current, and the final velocity of the superimposed ocean current and wake is calculated based on the corresponding final velocity calculation relationship of the superimposed ocean current and wake; The relative velocity component of the superimposed ocean current and wake is calculated based on the final velocity of the superimposed ocean current and wake, and the relative velocity component in the damping matrix of the ROV's dynamic model is updated to the relative velocity component of the superimposed ocean current and wake, completing the analysis of the comprehensive impact of the ocean current and wake on the ROV path.

2. The ROV ocean current and wake interference analysis method for offshore wind farms according to claim 1, characterized in that: The power law model is used to calculate the tidal velocity vectors at different depths in the shallow layer of the ocean current based on the tidal velocity vectors on the still water surface. Among them, V c is the tidal velocity vector on the still water surface, v c,tide (z) is the tidal velocity vector at depth z, z is the distance above the still water surface, positive is upward, d is the water depth, and e is the exponent.

3. The ROV ocean current and wake interference analysis method for offshore wind farms according to claim 1, characterized in that: Calculate the wake velocity vector based on the tidal velocity vector on the still water surface, V f =V c (1-△) (2); Among them, V c is the tidal velocity vector on the still water surface, V f is the wake velocity vector, △ is the wake velocity loss coefficient, and its value range is determined according to the shape, size, flow direction and angle of attack of the obstacle.

4. The ROV ocean current and wake interference analysis method for offshore wind farms according to claim 1, characterized in that: A three-dimensional vector model of ocean currents is constructed, and the direction of the ocean currents is decomposed in the Cartesian space coordinate system to obtain the projection velocity components of the tidal velocity vectors at different depths in the shallow layer of the ocean currents in the three main axis directions. The mathematical expression is: Among them, V current is the component of pure ocean current velocity, v c,tide (z) is the tidal velocity vector at depth 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 the projection velocity components of the tidal velocity vector at different depths in the shallow layer of the ocean current on the X-axis, Y-axis, and Z-axis respectively.

5. The ROV ocean current and wake interference analysis method for offshore wind farms according to claim 1, characterized in that: Construct a two-dimensional wake vector model, decompose the wake flow direction in the local coordinate system, and obtain the projection velocity components of the wake velocity vector in the X-axis and Y-axis directions. The mathematical expression is: Among them, V wake is the component of the pure wake velocity, β is the angle between the wake vector and the X-axis of the ROV's body coordinate system, are the projection velocity components of the wake velocity vector in the X-axis and Y-axis directions, respectively.

6. The ROV ocean current and wake interference analysis method for offshore wind farms according to claim 1, characterized in that: The area without wake influence is not affected by the wake. The direction of the wake is consistent with that of the ocean current in the influence area, and the wake velocity loss coefficient △=0.

5. The direction of the wake is opposite to that of the ocean current in the influence area, and the wake velocity loss coefficient △=0.

3.

7. The ROV ocean current and wake interference analysis method for offshore wind farms according to claim 1, characterized in that: The calculation relationship between the superimposed ocean current and the final velocity of the wake-free area is: V final =V current (5); Among them, V final V is the final velocity of the superimposed ocean current and wake, current is the component of pure ocean current velocity; The final velocity calculation relationship of the superimposed ocean current and wake in the area of ​​influence with the same direction of wake and ocean current is: Among them, V x 、V y 、V z are the projected velocity components of the final velocity affected by the superimposed ocean current and wake on the X-axis, Y-axis, and Z-axis, respectively. are the projection velocity components of the tidal velocity vector at different depths in the shallow layer of the ocean current on the X-axis, Y-axis, and Z-axis, respectively. are the projected velocity components of the wake velocity vector in the X-axis and Y-axis directions respectively; The final velocity calculation relationship of the superposition of the ocean current and the wake in the area with opposite influence directions is:

8. The ROV ocean current and wake interference analysis method for offshore wind farms according to claim 7, characterized in that: According to the initial position and target position of the ROV, its heading, that is, the direction of approaching the target, is determined. If the angle ω∈[-45°, +45°] between the direction of the ROV approaching the target and the ocean current, the ROV is in the area without wake influence, and then the final velocity under the influence of the superimposed ocean current and wake is calculated using formula (5); If the angle ω between the direction of the ROV approaching the target and the ocean current is (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 velocity affected by the superimposed ocean current and wake is calculated using formula (6); If the angle ω∈[135°, 225°] between the direction of the ROV approaching the target and the ocean current, the ROV is in the area where the wake and the ocean current are in opposite directions, and then the final velocity affected by the superimposed ocean current and wake is calculated using formula (7).

9. The ROV ocean current and wake interference analysis method for offshore wind farms according to claim 1, characterized in that: The relative velocity components of the superimposed ocean current and wake are calculated based on the final velocity of the superimposed ocean current and wake and the relative velocity components in the damping matrix of the ROV's dynamic model. Among them, X u 、Y v 、Z w are the linear damping coefficients of the X, Y, and Z axes in the damping matrix of the ROV dynamic model, D u1 、D v1 、D w1 are the linear damping coefficients of the X, Y, and Z axes due to the influence of the superimposed ocean current and wake, respectively. v is the velocity vector, defined as: v = [u, v, w, p, q, r] T , u, v, w are linear velocity components, p, q, r are angular velocity components; Update the relative velocity component in the damping matrix to the relative velocity component with the superimposed ocean current and wake effects, and complete the analysis of the comprehensive impact of ocean current and wake on the ROV path. The damping matrix after the updated components is: Among them, K p 、M q 、N r are the rotational damping coefficients in the angular velocity directions around the X, Y, and Z axes, respectively.

10. An ROV ocean current and wake interference analysis system for offshore wind farms, characterized in that: The method for analyzing the interference between ROV ocean current and wake for an offshore wind farm according to any one of claims 1 to 9 comprises: The ocean current calculation module is used to calculate the tidal velocity vectors at different depths in the shallow layer of the ocean current using a power law model based on the tidal velocity vectors on the still water surface of the offshore wind farm; A wake calculation module is used to calculate the wake velocity vector based on the tidal velocity vector on the still water surface of the offshore wind farm; The ocean current decomposition module is used to construct a three-dimensional vector model of ocean currents, decompose the direction of ocean currents, and obtain the projected velocity components of the tidal velocity vectors at different depths in the shallow layer of the ocean currents in the three main axis directions; The area division module is used to divide the operating area of ​​the remote-controlled underwater robot ROV into an area without wake influence, an area with wake influence in the same direction as the ocean current, and an area with wake influence in the opposite direction to the ocean current according to the influence of the wake; The wake decomposition module is used to construct a two-dimensional wake vector model, decompose the wake flow direction, and obtain the projected velocity components of the wake velocity vector in the X-axis and Y-axis directions; A relationship building module is used to combine the projected velocity components of the tidal velocity vector and the projected velocity components of the wake velocity vector at different depths in the shallow layer of the ocean current to respectively build a final velocity calculation relationship for the superimposed ocean current and wake influence in each affected area; The final velocity calculation module is used to determine the heading according to the initial position and target position of the ROV, determine the affected area of ​​the ROV according to the angle between the heading and the ocean current, and then calculate the final velocity of the superimposed ocean current and wake according to the corresponding final velocity calculation relationship of the superimposed ocean current and wake; The damping matrix update module is used to calculate the relative velocity component affected by the superimposed ocean current and wake according to the final velocity affected by the superimposed ocean current and wake, and update the relative velocity component in the damping matrix of the ROV dynamic model to the relative velocity component affected by the superimposed ocean current and wake.

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