An automatic modeling method for solar module water tanks

Abstract

This invention discloses an automatic modeling method for a solar module water tank, relating to the field of solar module structural modeling technology. The method includes: acquiring the original geometric data of the water tank beneath the solar module, decomposing the bottom planar features and two sidewall curved surface features; establishing initial mesh models for the bottom and sidewalls respectively, and discretizing them into multiple continuous cross-sectional rings along the length of the water tank; collecting contact pressure distribution data of the solar module on the water tank after installation, mapping it to the nodes of each cross-sectional ring, and calculating the vertical deformation displacement of the cross-sectional ring based on the pressure value; converting the vertical displacement into vertical displacements at both ends of the bottom line segment and rotational constraints at the free ends of the sidewall curved segments, using these constraints as boundary conditions to resolve the equilibrium form of each cross-sectional ring; performing radial basis function interpolation on the equilibrium forms of all cross-sectional rings along the length of the water tank to generate a three-dimensional curved surface model of the deformed water tank, and extracting the bottom drainage slope and sidewall opening angle from it.

Description

Technical Field

[0001] This invention relates to the field of solar module structure modeling technology, specifically to an automatic modeling method for solar module water tanks. Background Technology

[0002] Existing methods for modeling solar module drainage systems typically design based on geometric data under ideal, unloaded conditions, treating the drainage system as a rigid structure and ignoring the deformation caused by the contact pressure applied to the drainage system after solar module installation. Some solutions use finite element method (FEM) software to manually build the drainage system model and perform structural analysis, calculating deformation by manually setting boundary conditions and load distribution. However, this manual modeling process is cumbersome, inefficient, and highly dependent on the operator's experience. Furthermore, existing methods struggle to automatically separate the planar features of the drainage system bottom from the curved features of the sidewalls from the original geometric data, and cannot convert discrete cross-sectional ring deformation information into a continuous 3D model showing the actual deformation. Due to the lack of an accurate description of the actual deformation morphology of the drainage system, the extracted bottom drainage slope and sidewall opening angle often deviate from the true values, affecting the drainage performance and structural stability of the solar module. Therefore, how to automatically extract features from the original geometric data of the drainage system and build a deformable discrete model, and how to accurately solve the equilibrium morphology of the deformed drainage system based on the measured contact pressure distribution and generate the overall 3D surface, are pressing issues that need to be addressed in current technology. Summary of the Invention

[0003] This invention aims to solve the problems in existing solar module water tank modeling methods, such as the inability to automatically separate the bottom plane and side wall surface features from the original geometric data, and the lack of accurate calculation of the equilibrium shape after deformation based on the actual contact pressure distribution to generate a continuous three-dimensional surface model.

[0004] The objective of this invention can be achieved through the following technical solutions: This invention provides an automatic modeling method for solar module water tanks, aiming to solve the technical problem of distorted drainage performance evaluation caused by the lack of accurate modeling of the water tank's stress and deformation state after installation in existing technologies. As a technical solution of this invention, the method includes: acquiring the original geometric data of the water tank under the solar module in a stress-free state; decomposing the bottom planar features and the curved surface features of the two sidewalls of the water tank from the original geometric data; establishing initial mesh models of the bottom of the water tank and the two sidewalls based on the bottom planar features and the curved surface features of the two sidewalls, respectively; discretizing the initial mesh models of the bottom of the water tank and the two sidewalls along the length of the water tank into multiple continuous cross-sectional rings, each cross-sectional ring consisting of a bottom line segment and two sidewall curved segments connected end-to-end; collecting contact pressure distribution data applied to the water tank after the solar module is installed; and mapping the contact pressure distribution data to each cross-sectional ring. For each node on the surface ring, the vertical deformation displacement of the cross-section ring is calculated based on the pressure value borne by the node. This vertical deformation displacement is then converted into the vertical displacement of the two ends of the bottom segment and the angular constraints of the free ends of the two sidewall curved segments. Using these constraints as boundary conditions, the equilibrium state of each cross-section ring is re-solved. The re-solved equilibrium states of all cross-section rings are then interpolated radially along the length of the water tank to generate a three-dimensional surface model of the deformed water tank. The bottom drainage slope and sidewall opening angle are extracted from this three-dimensional surface model. This method combines the geometric features under unloaded conditions with the contact pressure distribution, reconstructing the deformation state based on the mechanical equilibrium of the cross-section rings. This accurately reflects the actual deformation of the water tank after the solar module is press-fitted, providing a high-precision geometric basis for extracting the drainage slope and sidewall opening angle, effectively improving the reliability of water tank drainage performance evaluation in photovoltaic systems.

[0005] In a preferred embodiment of the present invention, the specific steps for decomposing the bottom planar features and the curved surface features of the two side walls of the water tank from the original geometric data are as follows: The original geometric data is converted into a three-dimensional point cloud set; the normal vector of the three-dimensional point cloud set is estimated to obtain the normal vector direction of each point; points whose normal vector direction makes an angle less than a preset angle threshold with the vertical direction are removed to form a bottom point cloud subset; this bottom point cloud subset is fitted to the bottom planar features; the remaining points in the three-dimensional point cloud set are clustered into a left point cloud cluster and a right point cloud cluster according to their normal vector directions; the left point cloud cluster and the right point cloud cluster are fitted to the left side wall curved surface features and the right side wall curved surface features, respectively. This method uses the normal vector direction as a discrimination criterion, which can efficiently separate the bottom planar and the two side curved surfaces from the original point cloud, avoiding subjective errors caused by manual intervention, and providing accurate geometric input for the subsequent establishment of the mesh model.

[0006] Furthermore, the specific steps for discretizing the initial mesh model of the bottom of the water tank and the initial mesh models of the two side walls into multiple continuous cross-sectional rings along the length direction of the water tank are as follows: Multiple cutting planes are set along the length direction of the water tank according to a preset step size, each cutting plane being perpendicular to the length direction of the water tank; the intersection line of each cutting plane with the initial mesh model of the bottom of the water tank is calculated to obtain the bottom line segment; the intersection line of each cutting plane with the initial mesh model of the left side wall is calculated to obtain the left side wall curve segment; the intersection line of each cutting plane with the initial mesh model of the right side wall is calculated to obtain the right side wall curve segment; the bottom line segment, left side wall curve segment, and right side wall curve segment located on the same cutting plane are connected end-to-end in sequence to form the cross-sectional ring corresponding to that cutting plane. Using a cutting plane discretization process perpendicular to the length direction allows each cross-sectional ring to independently reflect the cross-sectional geometric features at that location. Simultaneously, the preset step size ensures a balance between the number and accuracy of cross-sectional rings, which is beneficial for the stable execution of subsequent mechanical calculations and interpolation reconstruction.

[0007] As a preferred embodiment of the present invention, the specific steps for collecting the contact pressure distribution data applied to the water tank after the solar module is installed are as follows: Multiple pressure sensing patches are arranged on the inner surface of the bottom and the inner surfaces of the two side walls of the water tank in an isoparametric element manner, with each pressure sensing patch corresponding to a grid cell; when the solar module is pressed onto the water tank, the pressure readings of all pressure sensing patches are read, and each pressure reading is assigned to all nodes of the grid cell containing that pressure sensing patch; the average pressure value of all nodes within the same cross-sectional ring along the length of the water tank is taken as the representative pressure value of that cross-sectional ring, and cubic spline smoothing is applied to the representative pressure values ​​of all cross-sectional rings to obtain the contact pressure distribution data. Through the arrangement of isoparametric element patches and the assignment of node values, the pressure data is directly associated with the grid cells, facilitating subsequent mapping to the cross-sectional ring nodes; cubic spline smoothing can eliminate local measurement noise, obtaining a continuous and smooth pressure distribution curve along the length direction, improving the input quality of deformation calculation.

[0008] Further, the specific steps for mapping the contact pressure distribution data to corresponding nodes on each cross-sectional ring are as follows: The contact pressure distribution data is discretely sampled along the length of the water tank to obtain the pressure value at each cutting plane position; for each cross-sectional ring corresponding to a cutting plane, the pressure value at that cutting plane position is evenly distributed to all nodes on the bottom line segment and the two side wall curve segments of that cross-sectional ring; when the number of nodes on the bottom line segment and the two side wall curve segments of the water tank is inconsistent, the inverse distance weighted interpolation method is used to interpolate the pressure value from the existing nodes to the target node. The inverse distance weighted interpolation method uses the following formula to interpolate the pressure value from the existing nodes to the target node:

[0009] in: The pressure interpolation result for the target node is expressed in Pascals. For the first The pressure value of each existing node, in Pascals; For the target node and the first Euclidean distance between existing nodes, in meters; The total number of existing nodes participating in the interpolation is dimensionless; the squaring operations in the denominator and numerator are also dimensionless. This interpolation method is based on distance weighting, which can maintain the continuity of pressure distribution even when the node distribution is uneven, ensuring the reasonable distribution of pressure values ​​of each node on different cross-section rings.

[0010] In a preferred embodiment of the present invention, the specific steps for calculating the vertical deformation displacement of the cross-sectional ring based on the pressure value borne by each node on the cross-sectional ring are as follows: The pressure value borne by each node on the cross-sectional ring is converted into a line-distributed load at that node; the line-distributed load of all nodes is integrated along the curved path of the cross-sectional ring to obtain the total load of the cross-sectional ring; each cross-sectional ring is simplified into a simply supported curved beam model; the vertical deflection in the span of the cross-sectional ring is calculated based on the total load of the cross-sectional ring and the length of the corresponding bottom segment; the vertical deflection in the span of the cross-sectional ring is multiplied by the distance ratio coefficient between each node on the cross-sectional ring and the midpoint of the bottom segment to obtain the vertical deformation displacement of each node. This step transforms the complex spatial pressure distribution into the deflection calculation of a simply supported curved beam, resulting in a clear physical model, high computational efficiency, and providing a preliminary deformation reference for subsequent boundary condition extraction.

[0011] Further, the specific steps for converting the vertical deformation displacement of each cross-section ring into the vertical displacement of the two ends of the bottom segment of the cross-section ring and the rotation constraint conditions of the free ends of the two side wall curved segments are as follows: extract the vertical displacement values ​​of the left and right ends of the bottom segment of the cross-section ring from the vertical deformation displacement of each cross-section ring, and use the vertical displacement values ​​of the left and right ends as the support settlement boundary conditions of the bottom segment of the cross-section ring; for the left side wall curved segment, based on the vertical displacement value of the left end of the bottom segment of the cross-section ring and the bending stiffness of the water tank material... The coefficient is used to calculate the change in angle of the free end of the left wall curve segment relative to the left endpoint of the bottom line segment. This change in angle is then added to the original free end angle of the left wall curve segment to form the angle constraint condition for the left wall curve segment. For the right wall curve segment, the change in angle of the free end of the right wall curve segment relative to the right endpoint of the bottom line segment is calculated based on the vertical displacement value of the right endpoint of the bottom line segment of the cross-section and the bending stiffness coefficient of the water tank material. This change in angle is then added to the original free end angle of the right wall curve segment to form the angle constraint condition for the right wall curve segment. The change in angle of the free end of the left wall curve segment relative to the left endpoint of the bottom line segment is calculated using the following formula:

[0012] in: The change in angle of the free end of the left side wall curve segment relative to the left end point of the bottom line segment is expressed in radians. The elastic modulus of the water tank material is expressed in Pascals. Let be the moment of inertia of the cross-section of the water tank, expressed in meters to the fourth power. This represents the vertical displacement of the left endpoint of the bottom line segment, in meters. The arc length of the left sidewall curve segment is given in meters. This conversion method quantitatively correlates support settlement with sidewall rotation through material mechanics relationships, enabling boundary conditions to accurately reflect the deformation coordination relationship between adjacent components and improving the physical consistency of equilibrium solutions.

[0013] In a preferred embodiment of the present invention, the bending stiffness coefficient of the water tank material is calculated based on the product of the elastic modulus and the moment of inertia of the cross section. This coefficient directly reflects the ability of the water tank cross section to resist bending deformation, providing a material property basis for calculating the change in rotation angle, and ensuring that the boundary conditions are consistent with the actual physical behavior.

[0014] Further, the specific steps for resolving the equilibrium state of each cross-sectional ring using the vertical displacements of the two ends of the bottom line segment and the rotation constraints of the free ends of the two side wall curve segments as boundary conditions are as follows: Discretize the bottom line segment and the two side wall curve segments of each cross-sectional ring into multiple beam elements, each beam element containing two end nodes, each end node having a vertical displacement degree of freedom and a rotation degree of freedom; apply the vertical displacements of the two ends of the bottom line segment as forced boundary conditions to the vertical displacement degrees of freedom of the left and right end nodes of the bottom line segment; apply the rotation constraints of the free ends of the left side wall curve segment as forced boundary conditions to the rotation degrees of freedom of the free end nodes of the left side wall curve segment, and apply the rotation constraints of the free ends of the right side wall curve segment as forced boundary conditions to the rotation degrees of freedom of the free end nodes of the right side wall curve segment; assemble the overall stiffness matrix for all beam elements, and solve the linear equation system after applying the above forced boundary conditions to obtain the updated vertical displacements and updated rotations of all nodes on each cross-sectional ring; reconstruct the equilibrium state of each cross-sectional ring based on the updated vertical displacements and updated rotations. This finite element solution method is based on discrete beam elements and can accurately handle complex boundary conditions. The obtained nodal displacements and rotations are exact solutions that satisfy mechanical equilibrium, providing reliable cross-sectional ring morphology data for subsequent three-dimensional surface reconstruction.

[0015] As a preferred embodiment of the present invention, the specific steps for extracting the bottom drainage slope and side wall opening angle of the deformed water tank from the three-dimensional curved surface model are as follows: extract the spatial coordinates of each point on the center line of the bottom of the water tank from the three-dimensional curved surface model, draw the bottom longitudinal curve with the length direction of the water tank as the abscissa and the height of each point on the center line of the bottom of the water tank as the ordinate, and calculate the angle between the line connecting the two ends of the bottom longitudinal curve and the horizontal plane as the bottom drainage slope; extract the spatial coordinates of each point on the top edge line of the left side wall and the top edge line of the right side wall from the three-dimensional curved surface model, calculate the angle between the line connecting the top edge point of the left side wall and the left end point of the bottom line segment at each cross-section position and the vertical direction as the left side wall opening angle, and calculate the angle between the line connecting the top edge point of the right side wall and the right end point of the bottom line segment at each cross-section position and the vertical direction as the right side wall opening angle; take the average of the left side wall opening angles at all cross-section positions to obtain the left side wall opening angle of the deformed water tank, and take the average of the right side wall opening angles at all cross-section positions to obtain the right side wall opening angle of the deformed water tank. This extraction method is based on the deformed three-dimensional surface model and directly uses geometric coordinates to calculate the drainage slope and opening angle, avoiding the errors caused by ignoring deformation in traditional methods. It can provide accurate optimization basis for the drainage design of photovoltaic modules.

[0016] Further, the specific steps for radial basis function interpolation along the length of the water tank after resolving the equilibrium shape of all cross-sectional rings are as follows: taking the position coordinates of each cutting plane as the center point of the radial basis function, and taking the equilibrium shape of the cross-sectional ring corresponding to each cutting plane as the function value at that center point; using multiple quadratic radial basis functions as the interpolation kernel function, calculating the radial distance between any two center points, and constructing a radial basis function interpolation matrix; solving the radial basis function interpolation matrix to obtain the weight coefficients corresponding to each center point; for any target position along the length of the water tank, obtaining the equilibrium shape of the cross-sectional ring at the target position by weighted summation based on the radial distance between the target position and each center point and the weight coefficients corresponding to each center point; arranging the equilibrium shapes of the cross-sectional rings at all target positions in order along the length of the water tank, and filling the gaps between adjacent cross-sectional rings with quadrilateral meshes to generate a three-dimensional surface model of the water tank after overall deformation. Radial basis function interpolation has the characteristics of global smoothness and arbitrary point interpolation, which enables the transition between discrete cross-section rings to be continuous and natural. The generated three-dimensional surface model not only retains the mechanical equilibrium characteristics of each cross-section ring, but also ensures the smoothness of the overall geometry, thus laying a reliable surface foundation for the accurate extraction of drainage slope and opening angle.

[0017] The beneficial effects of this invention are: This method decomposes the bottom planar features and the curved surface features of the two sidewalls of the water tank from the original geometric data, and establishes initial mesh models for the bottom and sidewalls respectively. These initial mesh models are then discretized into multiple continuous cross-sectional rings along the length of the water tank. This approach automatically distinguishes between the bottom planar point cloud and the sidewall curved surface point cloud using normal vector estimation and clustering methods, avoiding the subjective errors and inefficiencies caused by manual segmentation of geometric features. By discretizing the initial mesh model into cross-sectional rings along the length direction, the three-dimensional geometric information of the water tank is compressed into a series of two-dimensional cross-sectional rings, providing a structured data foundation for subsequent deformation calculations based on these rings. Using this method, the geometric feature extraction and discretization process of the water tank is fully automated, requiring no manual intervention, significantly improving modeling efficiency and repeatability while maintaining the integrity of the original geometric shape. The contact pressure distribution data applied to the water tank after the solar panels are installed is mapped to the nodes of each cross-sectional ring. Based on the node pressure values, the vertical deformation displacement of the cross-sectional ring is calculated. This displacement is then converted into vertical displacement at both ends of the bottom line segment of the cross-sectional ring and rotation constraints at the free ends of the sidewall curved segments. These constraints are used as boundary conditions to resolve the equilibrium state of each cross-sectional ring. Finally, radial basis function interpolation is performed along the length of the water tank to generate a three-dimensional surface model of the entire deformed water tank. This scheme accurately distributes the discrete pressure values ​​measured by the pressure sensing patch to the nodes of each cross-sectional ring through inverse distance weighted interpolation. Vertical deflection is then calculated based on a simply supported curved beam model, which is then converted into support settlement and rotation constraints. The equilibrium state is resolved using finite element beam elements, ensuring the mechanical consistency of the deformation calculation. The radial basis function interpolation method smooths and continues the equilibrium state of the discrete cross-sectional rings along the length, generating a complete three-dimensional surface, thereby extracting the bottom drainage slope and sidewall opening angle that closely approximate the actual deformation state. Compared to traditional schemes based on the assumption of ideal rigidity or manual finite element analysis, this scheme can reflect the non-uniform deformation of the water tank under actual installation pressure, obtain more accurate slope and opening angle parameters, and provide a reliable geometric basis for the drainage design and structural optimization of solar modules. Attached Figure Description

[0018] The invention will now be further described with reference to the accompanying drawings.

[0019] Figure 1 This is a schematic diagram illustrating the working principle of an automatic modeling method for a solar module water tank as described in this invention. Figure 2 This is a flowchart of the mapping between the discretization of the cross-section of the water tank and the pressure distribution; Figure 3 This is a flowchart of tunnel cross-section ring deformation analysis and three-dimensional surface modeling. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides an automatic modeling method for a solar module water tank, comprising: acquiring the original geometric data of the water tank under the solar module in an unloaded state; decomposing the bottom planar features and the curved surface features of the two sidewalls of the water tank from the original geometric data; establishing initial mesh models of the bottom of the water tank and the two sidewalls based on the bottom planar features and the curved surface features of the two sidewalls respectively; discretizing the initial mesh models of the bottom of the water tank and the two sidewalls along the length of the water tank into multiple continuous cross-sectional rings, each cross-sectional ring consisting of a bottom line segment and two sidewall curved segments connected end to end; collecting the contact pressure distribution data applied to the water tank after the solar module is installed; and mapping the contact pressure distribution data to... For each node on the cross-section ring, the vertical deformation displacement of the cross-section ring is calculated based on the pressure value borne by the node. The vertical deformation displacement of each cross-section ring is converted into the vertical displacement of the two ends of the bottom line segment and the rotation constraint conditions of the free ends of the two side wall curve segments. The equilibrium form of each cross-section ring is resolved using the vertical displacement of the two ends of the bottom line segment and the rotation constraint conditions of the free ends of the two side wall curve segments as boundary conditions. The equilibrium forms of all cross-section rings after resolving are interpolated radially along the length of the water tank to generate a three-dimensional surface model of the water tank after overall deformation. The bottom drainage slope and side wall opening angle of the water tank after deformation are extracted from the three-dimensional surface model.

[0022] Example 1: In a specific implementation, the steps for decomposing the bottom planar features and the curved surface features of the two sidewalls of the water tank from the original geometric data are as follows: The original geometric data is converted into a three-dimensional point cloud set. The three-dimensional point cloud set consists of several three-dimensional points, each containing x, y, and z coordinate information in space. Normal vector estimation is performed on the three-dimensional point cloud set to obtain the normal vector direction of each point. Principal component analysis is used for normal vector estimation. For each point in the three-dimensional point cloud set, a neighborhood point set within a preset radius is selected, the covariance matrix of the neighborhood point set is calculated, and the eigenvalues ​​and eigenvectors of the covariance matrix are solved. The eigenvector corresponding to the smallest eigenvalue is taken as the normal vector direction of that point.

[0023] In specific implementation, points whose normal vector direction and the vertical direction form an angle less than a preset threshold are removed to form a bottom point cloud subset. The vertical direction is defined as the gravity direction, i.e., the positive z-axis direction. The preset angle threshold is set to 30 degrees. For each point in the 3D point cloud set, the angle between the normal vector direction and the vertical direction is calculated. If the angle is less than 30 degrees, the point is assigned to the bottom point cloud subset. The bottom point cloud subset is fitted to a bottom plane feature. The fitting uses the least squares method. The coordinates of all points in the bottom point cloud subset are substituted into the plane equation z = ax + by + c, and the parameters a, b, and c are solved to minimize the sum of the squared distances of all points to the plane, thus obtaining the bottom plane feature.

[0024] In specific implementation, the remaining points in the 3D point cloud set are clustered into a left point cloud cluster and a right point cloud cluster according to the normal vector direction. The remaining points refer to the points remaining after removing the bottom point cloud subset from the 3D point cloud set. The K-means clustering algorithm is used for clustering, with the normal vector direction of each remaining point as the classification feature. The number of clusters is set to 2, corresponding to the left and right walls respectively. The left and right point cloud clusters are obtained through iterative calculation. The left and right point cloud clusters are then fitted to the left and right wall surface features respectively. Both the left and right wall surface features are fitted with quadratic surfaces, with the surface equation z=a0+a1*x+a2*y+a3*x²+a4*y²+a5*x*y. The coordinates of all points in the left point cloud cluster are solved using the least squares method to obtain the parameters of the left wall surface feature. Similarly, the coordinates of all points in the right point cloud cluster are solved using the least squares method to obtain the parameters of the right wall surface feature.

[0025] Example 2: In specific implementation, refer to Figure 2The specific steps for discretizing the initial mesh model of the bottom of the water tank and the initial mesh models of the two side walls into multiple continuous cross-sectional rings along the length of the water tank are as follows: Multiple cutting planes are set along the length of the water tank at a preset step size, each cutting plane perpendicular to the length of the water tank. The preset step size is set to 0.05 meters, and the value of the preset step size is based on the mesh resolution requirements along the length of the water tank, ensuring that the spacing between adjacent cutting planes can capture the geometric changes of the water tank. The intersection line of each cutting plane with the initial mesh model of the bottom of the water tank is calculated to obtain the bottom line segment; the intersection line of each cutting plane with the initial mesh model of the left side wall is calculated to obtain the left side wall curve segment; and the intersection line of each cutting plane with the initial mesh model of the right side wall is calculated to obtain the right side wall curve segment. The intersection lines are obtained by substituting the equations of the cutting planes into the triangular elements of the initial mesh model and performing linear interpolation. Connect the bottom line segment, the left side wall curve segment, and the right side wall curve segment located on the same cutting plane end to end in sequence to form a cross-sectional ring corresponding to the cutting plane. The two ends of the bottom line segment are connected to the lower ends of the left side wall curve segment and the right side wall curve segment, respectively. The upper ends of the left side wall curve segment and the upper ends of the right side wall curve segment are free ends.

[0026] In the specific implementation, the steps for collecting the contact pressure distribution data applied to the water tank after the solar modules are installed are as follows: Multiple pressure sensing patches are arranged on the inner surface of the bottom and the inner surfaces of the two side walls of the water tank using an isoparametric element method, with each pressure sensing patch corresponding to a grid cell. The isoparametric element method refers to dividing the inner surface of the water tank into grid cells consistent with the initial grid model, with a pressure sensing patch placed at the center of each grid cell. When the solar modules are pressed onto the water tank, the pressure readings of all pressure sensing patches are read, and each pressure reading is assigned to all nodes of the grid cell containing that pressure sensing patch. Each grid cell contains multiple nodes, and each node receives the same pressure reading as that grid cell. The average pressure value of all nodes within the same cross-sectional ring along the length of the water tank is taken as the representative pressure value of that cross-sectional ring. Cubic spline smoothing is applied to the representative pressure values ​​of all cross-sectional rings to obtain the contact pressure distribution data. The cubic spline smoothing uses natural boundary conditions, and the smoothed pressure value sequence is obtained by solving a tridiagonal system of equations.

[0027] In specific implementation, the steps for mapping the contact pressure distribution data to corresponding nodes on each cross-sectional ring are as follows: The contact pressure distribution data is discretely sampled along the length of the water tank to obtain the pressure value at each cutting plane position. The discrete sampling is obtained by taking values ​​from the pressure curve smoothed by a cubic spline at the cutting plane position. For each cross-sectional ring corresponding to a cutting plane, the pressure value at that cutting plane position is evenly distributed to all nodes on the bottom segment and the two sidewall curve segments of that cross-sectional ring. When the number of nodes on the bottom segment and the two sidewall curve segments of the water tank is inconsistent, the inverse distance weighted interpolation method is used to interpolate the pressure value from the existing nodes to the target node. The inverse distance weighted interpolation method uses the following formula to interpolate the pressure value from the existing nodes to the target node:

[0028] in: The pressure interpolation result for the target node is expressed in Pascals. For the first The pressure value of each existing node, in Pascals; For the target node and the first Euclidean distance between existing nodes, in meters; The total number of existing nodes participating in the interpolation is dimensionless; the squaring operations in the denominator and numerator are dimensionless. Existing nodes refer to nodes on the bottom line segment and the two sidewall curve segments of the cross-section ring that originally had pressure values ​​assigned to them. Target nodes refer to nodes on the cross-section ring that require additional pressure values. Total number of existing nodes participating in the interpolation. The value is the number of all existing nodes on the cross-section ring. When the Euclidean distance between the target node and an existing node is less than 0.001 meters, the pressure value of the existing node is directly assigned to the target node to avoid numerical instability caused by the denominator approaching zero.

[0029] Example 3: In specific implementation, the steps for calculating the vertical deformation displacement of the cross-sectional ring based on the pressure value borne by each node on the cross-sectional ring are as follows: (See...) Figure 3The pressure value borne by each node on the cross-section ring is converted into a line distributed load at that node. The total load of the cross-section ring is obtained by integrating the line distributed loads of all nodes along the curved path of the cross-section ring. The line distributed load is obtained by multiplying the pressure value of each node by the length influence coefficient corresponding to that node. The length influence coefficient is calculated based on the curved distance between adjacent nodes on the cross-section ring, and the length influence coefficient corresponding to each node is half of the sum of the arc lengths between that node and its preceding and following adjacent nodes. The integral of the curved path is performed using the composite trapezoidal method, summing segment by segment along the curved direction of the cross-section ring. Each cross-section ring is simplified as a curved beam model with simply supported ends. The vertical deflection at mid-span of the cross-section ring is calculated based on the total load of the cross-section ring and the length of the bottom line segment corresponding to the cross-section ring. The vertical deflection at mid-span is calculated using the deflection formula for a simply supported beam under uniformly distributed load in mechanics of materials. The total load is considered as a uniformly distributed load, and the load intensity is the total load divided by the length of the bottom line segment. The formula for calculating the deflection at mid-span is:

[0030] in: Vertical deflection at mid-span, in meters; The uniformly distributed load intensity is expressed in Newtons per meter. This is the length of the bottom line segment, in meters; This refers to the elastic modulus of the sink material, measured in Pascals. It is determined based on the actual material properties of the sink; for aluminum alloy sinks... Values Pascal; Let be the moment of inertia of the water tank cross-section, expressed in meters to the fourth power. It is calculated based on the cross-sectional dimensions of the water tank. For a rectangular cross-section, ,in For the cross-sectional width, The vertical deflection of the cross-section is multiplied by the distance ratio coefficient between each node on the cross-section and the midpoint of the bottom segment to obtain the vertical deformation displacement of each node. The distance ratio coefficient is determined as follows: For nodes on the bottom segment, the distance ratio coefficient is calculated based on the ratio of the horizontal distance between the node and the midpoint of the bottom segment to half the length of the bottom segment. The closer the node is to the midpoint of the bottom segment, the closer the distance ratio coefficient is to 1; the closer the node is to the endpoint of the bottom segment, the closer the distance ratio coefficient is to 0. For nodes on the sidewall curved segment, the distance ratio coefficient is calculated based on the ratio of the distance between the vertical projection position of the node and the vertical projection point corresponding to the midpoint of the bottom segment to the total height of the sidewall curved segment. The closer the node is to the top of the sidewall, the larger the distance ratio coefficient is, but it does not exceed 1.2.

[0031] In specific implementation, the steps for converting the vertical deformation displacement of each cross-section ring into the vertical displacement of the two ends of the bottom segment of the cross-section ring and the rotation constraint conditions of the free ends of the two sidewall curved segments are as follows: Extract the vertical displacement values ​​of the left and right ends of the bottom segment of the cross-section ring from the vertical deformation displacement of each cross-section ring, and use these vertical displacement values ​​as the support settlement boundary conditions for the bottom segment of the cross-section ring. The vertical displacement value of the left end of the bottom segment is denoted as... The unit is meters; the vertical displacement of the right endpoint of the bottom line segment is denoted as... The unit is meters, directly taken from the vertical deformation displacement of the left and right end nodes of the bottom segment of the cross-section ring. For the left side wall curve segment, the change in rotation angle of the free end of the left side wall curve segment relative to the left end of the bottom segment is calculated based on the vertical displacement value of the left end of the bottom segment of the cross-section ring and the bending stiffness coefficient of the water tank material. This change in rotation angle is added to the original free end rotation angle of the left side wall curve segment to form the rotation angle constraint condition of the left side wall curve segment. The bending stiffness coefficient of the water tank material is calculated based on the product of the elastic modulus of the water tank and the moment of inertia of the cross section, i.e., the bending stiffness coefficient. The unit is Newton-square meter. The change in angle of rotation of the free end of the left side wall curved segment relative to the left end point of the bottom line segment is calculated by the following formula:

[0032] in: The change in angle of the free end of the left side wall curve segment relative to the left end point of the bottom line segment is expressed in radians. This is the elastic modulus of the water tank material, measured in Pascals, with a range of values ​​of [value missing]. Pascal to Pascal, the specific value is selected based on the actual material of the sink; Let be the moment of inertia of the cross-section of the water tank, expressed in meters to the fourth power, with a range of values ​​of . The fourth power of meters The fourth power of the meter is calculated based on the specific dimensions of the water tank's cross-section. This is the vertical displacement value of the left endpoint of the bottom line segment, in meters, ranging from 0 meters to 0.05 meters, determined by the actual deformation. The arc length of the left sidewall curve segment, in meters, ranges from 0.02 meters to 0.2 meters, determined by the geometry of the water tank sidewall, and is calculated through the cumulative arc length between nodes on the left sidewall curve segment. For the right sidewall curve segment, the change in angle of the free end of the right sidewall curve segment relative to the right end of the bottom segment is calculated based on the vertical displacement value of the right endpoint of the bottom segment of the cross-section and the bending stiffness coefficient of the water tank material. This change in angle is added to the original free end angle of the right sidewall curve segment to form the angle constraint condition of the right sidewall curve segment. The change in angle of the free end of the right sidewall curve segment relative to the right end of the bottom segment is calculated using the following formula:

[0033] in: The change in angle of the free end of the right side wall curve segment relative to the right end of the bottom line segment is expressed in radians. This represents the vertical displacement of the right endpoint of the bottom line segment, in meters. The arc length of the right wall curve segment is in meters. Its range of values ​​is the same as that of the left wall curve segment and is determined by the geometric dimensions of the right wall curve segment. and The parameter values ​​are the same as those in the formula for the left side wall. The original free end rotation angle of the left side wall curve segment is initially set to 0 radians, meaning the angle between the free end of the left side wall curve segment and the horizontal direction is 0 when undeformed; the original free end rotation angle of the right side wall curve segment is also initially set to 0 radians. The added rotation angle constraint for the left side wall curve segment is that the rotation angle value of the free end of the left side wall curve segment is equal to the original free end rotation angle plus... The right side wall curve segment rotation constraint condition is that the rotation angle value of the free end of the right side wall curve segment is equal to the original free end rotation angle plus... .

[0034] Example 4: In specific implementation, the steps for resolving the equilibrium state of each cross-sectional ring using the vertical displacement of the two ends of the bottom line segment and the rotation constraints of the free ends of the two side wall curved segments as boundary conditions are as follows: The bottom line segment and the two side wall curved segments of each cross-sectional ring are discretized into multiple beam elements. Each beam element contains two end nodes, and each end node has vertical displacement and rotation degrees of freedom. The beam elements are Euler-Bernoulli beam elements. The length of each beam element is determined according to the node spacing on the curved segment. For the bottom line segment, the bottom line segment is divided into equal parts... Individual beam elements, With a value of 10, the bottom line segment is evenly divided into 10 segments, resulting in 11 nodes and forming 10 beam elements; for the left side wall curve segment, the left side wall curve segment is equally divided into Individual beam elements, The value is set to 8, and the left wall curve segment is evenly divided into 8 segments, resulting in 9 nodes and forming 8 beam elements; for the right wall curve segment, the right wall curve segment is equally divided into Individual beam elements, The value is set to 8, and the right side wall curve segment is evenly divided into 8 segments, resulting in 9 nodes and forming 8 beam elements. The bottom line segment, the left side wall curve segment, and the right side wall curve segment share nodes at their intersections; that is, the left end node of the bottom line segment and the lower end node of the left side wall curve segment are the same node, and the right end node of the bottom line segment and the lower end node of the right side wall curve segment are the same node. Each beam element contains two end nodes, and each end node has two degrees of freedom: vertical displacement and rotation. Therefore, each beam element has 4 degrees of freedom: vertical displacement of the left end node, rotation of the left end node, vertical displacement of the right end node, and rotation of the right end node.

[0035] In specific implementation, the vertical displacements of the two endpoints of the bottom line segment are applied as forced boundary conditions to the vertical displacement degrees of freedom of the left and right endpoints of the bottom line segment. The vertical displacement degree of freedom of the left endpoint of the bottom line segment is assigned the value of the vertical displacement of the left endpoint of the bottom line segment obtained from Example 3. The vertical displacement degree of freedom of the right end node of the bottom line segment is assigned the value of the vertical displacement of the right end point of the bottom line segment obtained from Example 3. The rotational constraint condition of the free end of the left wall curve segment is applied as a forced boundary condition to the rotational degree of freedom of the free end node of the left wall curve segment, and the rotational constraint condition of the free end of the right wall curve segment is applied as a forced boundary condition to the rotational degree of freedom of the free end node of the right wall curve segment. The rotational degree of freedom of the free end node of the left wall curve segment is assigned the value as the original free end rotation angle of the left wall curve segment plus the value obtained from Example 3. The original free end rotation angle of the left wall curve segment was set to 0 radians, therefore the rotational degree of freedom of the free end node of the left wall curve segment was assigned a value of Radius; the angular degree of freedom of the free end node of the right side wall curve segment is assigned the value as the original free end rotation angle of the right side wall curve segment plus the value obtained from Example 3. The original free end rotation angle of the right wall curve segment was set to 0 radians, therefore the angular degree of freedom of the free end node of the right wall curve segment was assigned a value of radian.

[0036] In practical implementation, the overall stiffness matrix is ​​assembled for all beam elements. After applying the aforementioned forced boundary conditions, the linear equations are solved to obtain the updated vertical displacement and updated rotation angle of all nodes on each section ring. The assembly process of the overall stiffness matrix is ​​as follows: For each beam element, the element stiffness matrix is ​​calculated based on the geometric and material parameters of the beam element. The element stiffness matrix adopts the standard Euler-Bernoulli beam element stiffness matrix formula, and the calculation formula is as follows:

[0037] in: is the element stiffness matrix, which is dimensionless and has units of Newtons per meter; The elastic modulus of the water tank material is expressed in Pascals, and its value is the same as that in Example 3. Similarly, for aluminum alloy water tanks, take Pascal; Let be the moment of inertia of the water tank cross-section, expressed in meters to the fourth power, and its value is the same as in Example 3. The same applies; it is calculated based on the cross-sectional dimensions of the water tank. The length of the beam element is in meters, determined by the segment length of the bottom line segment or the curved segment of the side wall. The element stiffness matrices of all beam elements are assembled according to the nodal degrees of freedom numbering to form the overall stiffness matrix. The order of the overall stiffness matrix is ​​the total number of nodes multiplied by the number of degrees of freedom of each node. The total number of nodes is the sum of the number of nodes on the bottom line segment, the left side wall curve segment, and the right side wall curve segment, minus the number of duplicate nodes at intersections. There are nodes, and the total degrees of freedom are... The forced boundary conditions include the vertical displacement degrees of freedom of the left end node of the bottom line segment, the vertical displacement degrees of freedom of the right end node of the bottom line segment, the rotation degrees of freedom of the free end node of the left side wall curve segment, and the rotation degrees of freedom of the free end node of the right side wall curve segment, for a total of four degrees of freedom being forcibly assigned values. When applying the forced boundary conditions, the large number method is used, multiplying the diagonal elements of the global stiffness matrix corresponding to the degrees of freedom of the forced boundary conditions by a large number (e.g., ...). The load terms for the corresponding degrees of freedom in the overall load matrix are set to large numbers multiplied by the forced displacement value. The overall load matrix consists of external loads acting on each node, including equivalent nodal forces generated by the pressure mapped to the nodes in Example 2. These equivalent nodal forces are obtained by converting distributed loads into equivalent nodal force vectors. The distributed loads on each beam element are converted into element equivalent nodal forces according to the equivalent nodal force formula, and then assembled into the overall load matrix. After applying boundary conditions, the linear equation system is solved. ,in For all nodes, there are unknown displacement vectors, including vertical displacement and rotation. This represents the overall load matrix after applying boundary conditions. The linear equations are solved using Gaussian elimination to obtain the updated vertical displacements and rotations of all nodes on each cross-section ring.

[0038] In practice, the equilibrium shape of each cross-sectional ring is reconstructed based on the updated vertical displacement and the updated rotation angle. The updated vertical displacement of each node is superimposed onto its original vertical coordinates in the initial mesh model to obtain the spatial position of the deformed node. The updated rotation angle of each node is used as the change in the inclination angle of the curve tangent at that node to adjust the geometric direction of the curve segment. Based on the deformed spatial positions of all nodes, a cubic spline interpolation method is used to generate continuous deformed curves on the bottom line segment, the left side wall curve segment, and the right side wall curve segment. The three curve segments are connected end to end in sequence to form the equilibrium shape of the resolved cross-sectional ring.

[0039] Example 5: In specific implementation, the steps for radial basis function interpolation along the length of the water tank after resolving the equilibrium state of all cross-sectional rings are as follows: The position coordinates of each cutting plane are taken as the center point of the radial basis function, and the equilibrium state of the cross-sectional ring corresponding to each cutting plane is taken as the function value at that center point. The position coordinates of the cutting plane are one-dimensional coordinates along the length of the water tank, denoted as... The unit is meters, and the value range is from the starting coordinate to the ending coordinate along the length of the water tank. The equilibrium shape of the cross-section ring includes the deformed spatial coordinates of all nodes on the cross-section ring. For each node, its spatial coordinates include a horizontal coordinate, a horizontal coordinate, and a vertical coordinate, where the horizontal coordinate is the same as the coordinate along the length of the water tank. Consistent, the horizontal coordinates and vertical coordinates are used as the function value vector at the center point.

[0040] In practice, multiple quadratic radial basis functions are used as the interpolation kernel function to calculate the radial distance between any two center points, thus constructing the radial basis function interpolation matrix. The expression for the multiple quadratic radial basis functions is as follows: ,in For the first The center point and the first The Euclidean distance between the center points, in meters, is calculated using the following formula: ; The shape parameter, in meters, ranges from 0.01 to 0.1 meters, specifically set to 0.05 meters. This value of 0.05 meters ensures that the radial basis function produces a smooth and non-singular interpolation result within the spacing between adjacent cutting planes (preset step size of 0.05 meters). The total number of center points is... The total number of center points is equal to the number of cutting planes set along the length of the water tank. According to Embodiment 2, cutting planes are set along the length of the water tank at a preset step size of 0.05 meters. Assuming the length of the water tank is 2 meters, then... The value is 41. Radial basis function interpolation matrix. for A square matrix, the first element in the matrix is... Line 1 Column elements are .

[0041] In practice, the radial basis function interpolation matrix is ​​solved to obtain the weight coefficients corresponding to each center point. For each variable to be interpolated (e.g., node horizontal coordinates or node height coordinates), a system of linear equations is established. ,in Let be the weight coefficient vector, with dimension . ; This is a vector of function values ​​for the variable at each center point, with dimension . The linear equations are solved using the LU decomposition method to obtain the weight coefficient vector. For any target location along the length of the water tank, the cross-sectional ring equilibrium shape at that target location is obtained by weighted summation based on the radial distance between the target location and each center point, and the weighting coefficient corresponding to each center point. The target location is denoted as... The unit is meters, and the value ranges to any position along the length of the water tank. Calculate the radial distance between the target position and each center point. Substituting the values ​​into the radial basis functions yields the interpolation basis function values. Then the interpolation result of the variable at the target location is: ,in For the first The weight coefficients corresponding to each center point are then used. The above interpolation is applied to all node coordinate variables to obtain the equilibrium shape of the complete cross-sectional ring at the target location.

[0042] In the specific implementation, the equilibrium shapes of the cross-sectional rings at all target locations are arranged sequentially along the length of the water tank. Quadrilateral meshes are used to fill the spaces between adjacent cross-sectional rings to generate a three-dimensional surface model of the deformed water tank. The target locations are selected by uniformly sampling at 0.01-meter intervals along the length of the water tank to obtain a series of target locations. For each pair of adjacent target locations, the corresponding equilibrium shape of the cross-sectional rings is obtained. Nodes with the same number on the two cross-sectional rings are connected by straight line segments, and quadrilateral mesh units are generated between the corresponding curve segments of the two adjacent cross-sectional rings. Each quadrilateral mesh unit consists of four adjacent nodes on two adjacent cross-sectional rings, and each quadrilateral mesh unit contains four vertices. All quadrilateral mesh units are arranged sequentially along the length of the water tank to form a three-dimensional surface model of the deformed water tank.

[0043] In specific implementation, the steps for extracting the bottom drainage slope and sidewall opening angle of the deformed water tank from the three-dimensional curved surface model are as follows: Extract the spatial coordinates of each point on the centerline of the bottom of the water tank from the three-dimensional curved surface model. Draw a longitudinal curve of the bottom with the length of the water tank as the abscissa and the height of each point on the centerline of the bottom of the water tank as the ordinate. The centerline of the bottom is defined as the centerline of the bottom of the water tank in the transverse direction. For each cross-sectional ring, the bottom midpoint is the midpoint of the bottom line segment, and its spatial coordinates are obtained by linear interpolation of the coordinates of the two endpoints of the bottom line segment. Calculate the angle between the line connecting the two endpoints of the longitudinal curve of the bottom and the horizontal plane as the bottom drainage slope. The two endpoints of the longitudinal curve of the bottom are the bottom midpoints at the starting and ending positions along the length of the water tank, respectively. Let the height of the bottom midpoint at the starting position be... The unit is meters, and the height of the bottom midpoint of the termination position is... The unit is meters, and the length of the water tank is... The unit is meters, then the bottom drainage slope The unit is degrees.

[0044] In specific implementation, the spatial coordinates of each point on the top edge line of the left side wall and the top edge line of the right side wall are extracted from the three-dimensional curved surface model. The top edge line of the left side wall is the line connecting the free end nodes of the left side wall curved segment in each cross-sectional ring, and the top edge line of the right side wall is the line connecting the free end nodes of the right side wall curved segment in each cross-sectional ring. The angle between the line connecting the top edge point of the left side wall and the left endpoint of the bottom line segment at each cross-sectional position and the vertical direction is calculated as the opening angle of the left side wall. Let the spatial coordinates of the top edge point of the left side wall at a certain cross-sectional position be... The spatial coordinates of the left endpoint of the bottom line segment are Then the opening angle of the left side wall The unit is degrees. Calculate the angle between the line connecting the top edge point of the right side wall and the right endpoint of the bottom line segment at each cross-section location and the vertical direction as the opening angle of the right side wall. Let the spatial coordinates of the top edge point of the right side wall at a certain cross-section location be... The spatial coordinates of the right endpoint of the bottom line segment are Then the opening angle of the right side wall The unit is degrees. The left wall opening angle after tank deformation is obtained by averaging the left wall opening angles at all cross-sectional locations, and the right wall opening angle after tank deformation is obtained by averaging the right wall opening angles at all cross-sectional locations. The total number of cross-sectional locations is the number of target locations, denoted as . The average opening angle of the left side wall Average opening angle of the right side wall .

[0045] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A method for automatically modeling the water tank of a solar module, characterized in that, include: Obtain the original geometric data of the water tank under the solar panel in an unloaded state, and decompose the bottom planar features and the curved surface features of the two side walls of the water tank from the original geometric data; Based on the bottom planar features and the curved surface features of the two sidewalls, an initial mesh model of the bottom of the water tank and an initial mesh model of the two sidewalls are established respectively. The initial mesh model of the bottom of the water tank and the initial mesh model of the two sidewalls are discretized into multiple continuous cross-sectional rings along the length of the water tank. Each cross-sectional ring is composed of a bottom line segment and two sidewall curved segments connected end to end. Collect contact pressure distribution data applied to the water tank after the solar panel is installed, map the contact pressure distribution data to the corresponding node on each cross-sectional ring, and calculate the deformation displacement of the cross-sectional ring in the vertical direction based on the pressure value borne by the node on each cross-sectional ring. The vertical deformation displacement of each cross-section ring is converted into the vertical displacement of the two ends of the bottom line segment in the cross-section ring and the rotation constraint conditions of the free ends of the two side wall curve segments. The equilibrium state of each cross-section ring is resolved using the vertical displacement of the two ends of the bottom line segment and the rotation constraint conditions of the free ends of the two side wall curve segments as boundary conditions. After resolving all cross-sectional rings, the equilibrium shape is interpolated radially along the length of the water tank using basis functions to generate a three-dimensional surface model of the water tank after overall deformation. The bottom drainage slope and side wall opening angle of the water tank after deformation are extracted from the three-dimensional surface model.

2. The automatic modeling method for a solar module water tank according to claim 1, characterized in that, The specific steps for decomposing the bottom planar features and the curved surface features of the two sidewalls of the water tank from the original geometric data are as follows: The original geometric data is converted into a three-dimensional point cloud set, and the normal vector of each point is estimated by performing normal vector estimation on the three-dimensional point cloud set. Points whose normal vector direction and the vertical direction make an angle less than a preset angle threshold are removed to form a bottom point cloud subset, and the bottom point cloud subset is fitted to a bottom plane feature. The remaining points in the three-dimensional point cloud set are clustered into a left point cloud cluster and a right point cloud cluster according to the normal vector direction. The left point cloud cluster and the right point cloud cluster are then fitted with left wall surface features and right wall surface features, respectively.

3. The automatic modeling method for a solar module water tank according to claim 2, characterized in that, The specific steps for discretizing the initial mesh model at the bottom of the water tank and the initial mesh models of the two side walls into multiple continuous cross-sectional rings along the length of the water tank are as follows: Multiple cutting planes are set along the length of the water tank according to a preset step size, and each cutting plane is perpendicular to the length of the water tank. The bottom line segment is obtained by calculating the intersection line of each cutting plane with the initial mesh model of the bottom of the tank; the left wall curve segment is obtained by calculating the intersection line of each cutting plane with the initial mesh model of the left side wall; and the right wall curve segment is obtained by calculating the intersection line of each cutting plane with the initial mesh model of the right side wall. Connect the bottom line segment, the left side wall curve segment, and the right side wall curve segment located on the same cutting plane in sequence to form the cross-sectional ring corresponding to the cutting plane.

4. The automatic modeling method for a solar module water tank according to claim 3, characterized in that, The specific steps for collecting the contact pressure distribution data applied to the water tank after the solar panel is installed are as follows: Multiple pressure sensing patches are arranged in an isoparametric manner on the inner surface of the bottom of the water tank and the inner surfaces of the two side walls. Each pressure sensing patch corresponds to a grid cell. When the solar panels are pressed onto the water tank, read the pressure readings of all pressure sensor patches and assign each pressure reading to all nodes of the grid cell where the pressure sensor patch is located. The average pressure value of all nodes in the same cross-sectional ring along the length of the water tank is taken as the representative pressure value of that cross-sectional ring. The contact pressure distribution data is obtained by performing cubic spline smoothing on the representative pressure values ​​of all cross-sectional rings.

5. The automatic modeling method for a solar module water tank according to claim 4, characterized in that, The specific steps for mapping the contact pressure distribution data to the corresponding nodes on each cross-sectional ring are as follows: The contact pressure distribution data is discretely sampled along the length of the water tank to obtain the pressure value at each cutting plane position. For each section ring corresponding to a cutting plane, the pressure value at the location of the cutting plane is evenly distributed to all nodes of the bottom line segment and the two side wall curve segments of the section ring; When the number of nodes on the bottom line segment and the two side wall curve segments of the water tank is inconsistent, the pressure value is interpolated from the existing nodes to the target node using the inverse distance weighted interpolation method.

6. The automatic modeling method for a solar module water tank according to claim 5, characterized in that, The specific steps for calculating the vertical deformation displacement of the cross-sectional ring based on the pressure value borne by the nodes on each cross-sectional ring are as follows: The pressure value borne by each node on the cross-section ring is converted into a line distributed load at that node. The total load of the cross-section ring is obtained by integrating the line distributed loads of all nodes along the curve path of the cross-section ring. Each cross-section ring is simplified as a curved beam model with simple support at both ends. The vertical deflection at the mid-span of the cross-section ring is calculated based on the total load on the cross-section ring and the length of the bottom line segment corresponding to the cross-section ring. Multiply the vertical deflection at the mid-span of the cross section by the proportionality coefficient of the distance between each node on the cross section and the midpoint of the bottom line segment to obtain the vertical deformation displacement of each node.

7. The automatic modeling method for a solar module water tank according to claim 6, characterized in that, The specific steps for converting the vertical deformation displacement of each cross-section ring into the vertical displacement of the two ends of the bottom line segment in the cross-section ring and the rotation constraint conditions of the free ends of the two side wall curved segments are as follows: Extract the vertical displacement values ​​of the left and right ends of the bottom segment of each cross-section ring from the vertical deformation displacement of each cross-section ring, and use the vertical displacement values ​​of the left and right ends as the support settlement boundary conditions of the bottom segment of the cross-section ring. For the left side wall curved segment, the change in the rotation angle of the free end of the left side wall curved segment relative to the left end of the bottom line segment is calculated based on the vertical displacement value of the left end of the bottom line segment of the cross section and the bending stiffness coefficient of the water tank material. The change in rotation angle is then added to the original free end rotation angle of the left side wall curved segment to form the rotation angle constraint condition of the left side wall curved segment. For the right side wall curved segment, the change in rotation angle of the free end of the right side wall curved segment relative to the right end of the bottom line segment is calculated based on the vertical displacement value of the right end of the bottom line segment of the cross section and the bending stiffness coefficient of the water tank material. The change in rotation angle is then added to the original free end rotation angle of the right side wall curved segment to form the rotation angle constraint condition of the right side wall curved segment.

8. The automatic modeling method for a solar module water tank according to claim 7, characterized in that, The bending stiffness coefficient of the water tank material is calculated based on the product of the elastic modulus and the moment of inertia of the cross section of the water tank.

9. The automatic modeling method for a solar module water tank according to claim 7, characterized in that, The specific steps for resolving the equilibrium state of each cross-section ring using the vertical displacement of the two ends of the bottom line segment and the rotation constraints of the free ends of the two side wall curved segments as boundary conditions are as follows: The bottom line segment and two side wall curved segments of each cross section ring are discretized into multiple beam elements. Each beam element contains two end nodes, and each end node has vertical displacement degree of freedom and rotation degree of freedom. The vertical displacements of the two ends of the bottom line segment are applied as forced boundary conditions to the vertical displacement degrees of freedom of the left and right end nodes of the bottom line segment. The rotation constraint condition of the free end of the left wall curve segment is applied as a forced boundary condition to the rotation degree of freedom of the free end node of the left wall curve segment, and the rotation constraint condition of the free end of the right wall curve segment is applied as a forced boundary condition to the rotation degree of freedom of the free end node of the right wall curve segment. Assemble the overall stiffness matrix for all beam elements, and solve the linear equations after applying the above-mentioned forced boundary conditions to obtain the updated vertical displacement and updated rotation angle of all nodes on each cross section ring. Reconstruct the equilibrium form of each cross section ring based on the updated vertical displacement and updated rotation angle.

10. The automatic modeling method for a solar module water tank according to claim 1, characterized in that, The specific steps for extracting the bottom drainage slope and side wall opening angle of the deformed water tank from the three-dimensional curved surface model are as follows: The spatial coordinates of each point on the center line of the bottom of the water tank are extracted from the three-dimensional curved surface model. The bottom longitudinal curve is drawn with the length of the water tank as the abscissa and the height of each point on the center line of the bottom of the water tank as the ordinate. The angle between the line connecting the two ends of the bottom longitudinal curve and the horizontal plane is calculated as the bottom drainage slope. The spatial coordinates of each point on the top edge line of the left side wall and the spatial coordinates of each point on the top edge line of the right side wall are extracted from the three-dimensional curved surface model. The angle between the line connecting the top edge point of the left side wall and the left endpoint of the bottom line segment at each cross-section position and the vertical direction is calculated as the opening angle of the left side wall. The angle between the line connecting the top edge point of the right side wall and the right endpoint of the bottom line segment at each cross-section position and the vertical direction is calculated as the opening angle of the right side wall. The average of the left side wall opening angles at all cross-sectional locations is used to obtain the left side wall opening angle after the water tank is deformed. The average of the right side wall opening angles at all cross-sectional locations is used to obtain the right side wall opening angle after the water tank is deformed.

Images