Ship molded line parametric modeling method, storage medium and system

Abstract

The invention belongs to the technical field of ship engineering CAD (computer-aided design) three-dimensional modeling, and particularly relates to a ship molded line parameterization modeling method, a storage medium and a ship molded line parameterization modeling system.The ship molded line parameterization modeling method comprises the steps that point models in three-dimensional modeling are classified and differentially expressed; classifying the line model of the hull molded line, and controlling the geometrical shape of the line model through parameters; based on classification of the point model and the line model, a relevance control mechanism is established, and a three-dimensional line frame is generated through interpolation, fairing and synchronous optimization of the molded line. Based on point and line categories and different parameter relevance, in the overall design stage, molded line three-dimensional modeling is carried out whether the molded line is designed preliminarily or under the condition of existing molded values, and the three-dimensional line frame is generated. The method has the advantages that the molded lines can be quickly created and optimized, the molded lines related to the points can be synchronously modified by modifying and fairing the points or the lines, and preconditions are provided for follow-up construction of the fairing hull molded surface by the molded lines.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D modeling in ship engineering CAD, and specifically relates to a parametric modeling method, storage medium, and system for ship hull lines. Background Art

[0002] In the ship design stage, in order to determine the shape of the hull line, it is necessary to design the ship hull line, and based on this, the optimization design of the ship hull line and the optimization of the general arrangement design plan can be carried out. In recent years, with the rapid development and gradual popularization of computer-aided design, the traditional method of manually designing and optimizing the ship hull line on a drawing board has been completely replaced. Instead, the three-dimensional modeling and optimization modification of the ship hull line are carried out interactively on computer software, which makes the design of the ship hull line more intuitive and efficient. There are many foreign ship hull line design software, and the functions of interactive design and parametric design have been basically realized. However, domestic three-dimensional hull line design software is still in its initial stage, with relatively single functions and unable to meet the diverse design and modification of hull lines. Domestic classification society checking software is more inclined to performance calculation and checking, and has the modeling construction of simple ship hull lines. In the general environment of the country's strong support for the independent research and development of domestic shipbuilding industry software, this patent will combine the characteristics of ship hull lines and three-dimensional spatial relationships to construct a three-dimensional parametric modeling design method for ship hull lines, which can quickly realize the three-dimensional design and optimization modification of ship hull lines. Summary of the Invention

[0003] To solve the problems raised in the above background art, the present invention provides a parametric modeling method, storage medium, and system for ship hull lines.

[0004] To achieve the above object, the first aspect of the present invention provides a parametric modeling method for ship hull lines, which is based on the geometric characteristics of ship hull lines and includes the following steps:

[0005] Step S100, classifying the point models in 3D modeling and expressing them differentially;

[0006] Step S200, classifying the line models of the ship hull line and controlling their geometric shapes through parameters;

[0007] Step S300, based on the classification of the point model and the line model, establishing a correlation control mechanism, and generating a 3D wireframe by interpolation, fairing, and synchronous optimization of the hull line.

[0008] As a technical solution of the present invention, in step S100, the classification and differential expression of the point model include:

[0009] Ordinary points, defined by absolute value coordinates and marked with the first color and the first symbol;

[0010] The knuckle point is located in the knuckle area of ​​the hull line or the transition area of ​​the curved surface and is marked with the second color and the second symbol;

[0011] Tangent points, points tangent to the arc profile, are marked with the third color and third symbol;

[0012] Reference points are generated by referencing the intersection of lines or surfaces, including reference points without type values ​​and reference points with type values, and are marked with the fourth color and the fourth symbol.

[0013] As a technical solution of the present invention, in step S200, the line model classification includes:

[0014] Space lines express the boundary characteristics of the hull shape;

[0015] Transverse section line, the intersection line of the section plane parallel to the mid-station plane and the hull surface;

[0016] Waterline, the intersection of horizontal planes at different heights with the hull surface;

[0017] Longitudinal section line is the intersection line of the sectioning plane parallel to the centerline and the hull surface.

[0018] As a technical solution of the present invention, in step S300, the relevance control mechanism includes:

[0019] Define the local curvature characteristics of a single profile by cutting in angle, cutting out angle and arc radius;

[0020] Establish reference relationships between lines through logical conditions, including intersections within specific ranges and intersections between two lines.

[0021] As a technical solution of the present invention, in step S300, a parameter optimization method is also included, including the following steps:

[0022] Step S301, based on the initial three-dimensional wireframe constructed by the space lines, the space lines and the generated cross-section lines, water lines and longitudinal sections are interpolated, smoothed and synchronously optimized;

[0023] Step S302, based on the optimized transverse section line, waterline, longitudinal section line and space line, the lines of the hull surface change area are interpolated, created and encrypted, and the relevant lines are optimized simultaneously to form a smooth 3D wireframe of the hull lines.

[0024] As a technical solution of the present invention, the logical condition includes at least one of the following forms:

[0025] Specific range intersection, the position of the reference point is defined by "referenced line name / coordinate axis=value";

[0026] The intersection point of two lines is defined by "referenced line A name / referenced line B name".

[0027] As a technical solution of the present invention, the fairing optimization includes:

[0028] When modifying the cutting-in angle or cutting-out angle of a single point, automatically adjust the curvature parameters of the associated fair curve;

[0029] When adjusting the arc radius of the line model, synchronously update the intersection positions of adjacent waterlines and longitudinal sections;

[0030] Detect the curvature continuity and modify the fair curve with differences for the fair curve that does not meet the set continuity.

[0031] As a technical solution of the present invention, for the non-profile value reference point, directly reference the intersection points of other lines or surfaces without attaching profile value parameters;

[0032] For the profile value reference point, attach profile value coordinates on the basis of referencing the intersection point to forcibly constrain the shape of the fair curve.

[0033] The second aspect of the present invention proposes a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the above method is implemented.

[0034] The third aspect of the present invention proposes a parametric modeling system for ship fair curves, including:

[0035] A user interaction module for inputting ship fair curve parameters and modification instructions;

[0036] A data processing module for executing the above method;

[0037] A visualization module for real-time displaying a three-dimensional wireframe and the optimization result.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] Based on the point, line categories and different parameter association relationships, in the overall design stage, whether it is the preliminary design fair curve or the three-dimensional modeling of the fair curve in the case of existing profile values, the fair curve can be quickly created and optimized. By modifying or fairing the point or line, the fair curve related to this point can be synchronously modified, providing a prerequisite for constructing a fair ship hull surface for the subsequent fair curve. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic flow chart of the modeling method of the present invention;

[0041] Figure 2 It is a flow chart of the parameter optimization method in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] The present invention designs methods for the attributes of basic elements such as three-dimensional space points and lines in three-dimensional software, and precisely expresses special points, ordinary points, special lines, and ordinary lines in the ship hull form by category. In this way, the basic element model data can be classified and processed, making the modeling well-organized, clear, and better for creating, managing, modifying, and optimizing the model data. A logical method is designed to establish the association relationship between points and lines, and between lines and lines, laying a certain foundation for subsequent parametric modeling and form optimization.

[0044] As Figure 1-2 shown. A method for parametric modeling of ship hull form provided by the first aspect of the present invention, based on the geometric characteristics of the ship hull form, includes the following steps:

[0045] Step S100, classifying the point models in three-dimensional modeling and expressing them differentially.

[0046] Specifically, the classification and differential expression of the point models include:

[0047] Ordinary points are defined by absolute value coordinates and marked with a first color and a first symbol; corner points are located in the corner area or the surface transition area of the ship hull form and are marked with a second color and a second symbol; tangent points are points tangent to the arc-shaped line and are marked with a third color and a third symbol; reference points are generated through the intersection points of reference lines or surfaces, including non-profile reference points and profile reference points, and are marked with a fourth color and a fourth symbol. The non-profile reference points directly reference the intersection points of other lines or surfaces without additional profile parameters; the profile reference points are appended with profile coordinates on the basis of referencing the intersection points to forcibly constrain the shape of the form.

[0048] As an example, the point models in three-dimensional overall design software can be divided into various types according to their functional characteristics and are expressed using different shape symbols and different colors. The expression of the point models is shown in Table 1 below:

[0049] Table 1

[0050]

[0051] According to the position of the three-dimensional space points on the ship hull surface and the curve characteristics of the passing points, these point model shapes can be expressed individually or superimposed, and the geometric space characteristics of the points can be intuitively reflected through the color and shape of the points.

[0052] Step S200, classifying the line model of the hull lines and controlling its geometric shape through parameters.

[0053] Specifically, the line model categories include: spatial lines, which express the boundary characteristics of the hull shape; transverse lines, which are the intersection lines of the cutting plane parallel to the mid-plane and the hull surface; waterlines, which are the intersection lines of horizontal planes at different heights and the hull surface; longitudinal lines, which are the intersection lines of the cutting plane parallel to the midline plane and the hull surface.

[0054] More specifically, the hull lines are divided into four categories according to their characteristics: space lines, cross-section lines, water lines, and longitudinal sections. These lines are used to express the shape of the hull. The space line is a boundary curve that reflects the boundary characteristics of the hull shape. The cross-section line reflects the lateral position of the hull, the waterline reflects the horizontal position of the hull, and the longitudinal section line reflects the longitudinal position of the hull. These line models are expressed in a specified language (the following table takes English and abbreviations as examples, and does not limit the present invention in any way), and then displayed in different colors, which is more convenient. The line model expression is specifically shown in Table 2 below:

[0055] Table 2

[0056]

[0057]

[0058] At the same time, for the shape control of the line passing point, there are three parameters to control the shape of the hull line: entry angle, type value coordinates, cut-out angle, reference object, and arc radius. Taking the cross-section line as an example, the specific hull line parameters are expressed in the following Table 3:

[0059] Table 3

[0060] Cut-in angle Y value Z value Cut-out angle Cited object Arc radius 0 0 CL 0.5 0 0 0.536 0 0 FBL

[0061] The cut-in angle and cut-out angle reflect the curvature of the curve at that point. The cut-in angle expresses the curvature of the profile when it enters the point, and the cut-out angle expresses the starting curvature of the profile at the point. The arc radius expresses that the profile is an arc line and an arc radius at the point. The angle values ​​of the cut-in angle and the cut-out angle represent the angle with the positive axis direction of the corresponding coordinate axis, with the counterclockwise direction being positive and the clockwise direction being negative. The corresponding angle column can be in the default state or in the free angle form. Among them, the angle expression method is as shown in Table 4:

[0062] Table 4

[0063]

[0064] The referenced object can be an intersection point within a specific range, an intersection point on a line, etc. The reference relationship between lines mainly establishes an intersection relationship under certain conditions, such as S6 / X = 3.2, CL / X > 35, CL / X = ~3.2, etc. Specifically, as shown in Table 5 below:

[0065] Table 5

[0066]

[0067] During the modeling process of the hull lines, there are intersection relationships among four types of lines: the hull space line, the transverse section line, the waterline, and the longitudinal section line. The hull lines need to form a three-dimensional wireframe with intersection relationships in three-dimensional space. Through these intersecting three-dimensional relationships, the lines can be quickly interpolated, modified, intersected, and deleted to adjust the shape of the hull surface. Therefore, in the lines, according to this reference relationship, the lines can be divided into reference lines and referenced lines. For example, if curve M references a point on curve N, then curve M is the reference line and curve N is the referenced line.

[0068] Step S300, based on the classification of the point model and the line model, establish an association control mechanism to generate a three-dimensional wireframe by interpolating, fairing, and synchronously optimizing the lines. The association control mechanism includes: defining the local curvature characteristics of a single line through the cut-in angle, cut-out angle, and arc radius; establishing the reference relationship between lines through logical conditions, including intersection points within a specific range and intersection points of two lines. Among them, the logical conditions include: for intersection points within a specific range, the position of the reference point is defined by "referenced line name / coordinate axis = value"; for intersection points of two lines, the intersection point of two lines is defined by "referenced line A name / referenced line B name". The fairing optimization includes: when modifying the cut-in angle or cut-out angle of a single point, automatically adjusting the curvature parameters of the associated lines; when adjusting the arc radius of the line model, synchronously updating the intersection positions of adjacent waterlines and longitudinal section lines; detecting the curvature continuity and performing interpolation modification on the lines that do not meet the set continuity.

[0069] The parameter optimization method includes the following steps:

[0070] Step S301, based on the initial three-dimensional wireframe constructed by the space line, interpolate, fair, and synchronously optimize the space line and the generated transverse section line, waterline, and longitudinal section line; Step S302, according to the optimized transverse section line, waterline, longitudinal section line, and space line, perform interpolation creation and densification on the lines in the hull surface change area, and synchronously optimize the relevant lines to form a fair three-dimensional wireframe of the hull lines.

[0071] Specifically, the overall design software performs the hull line modeling process as follows:

[0072] Based on the given offset values of the spatial line segments, the coordinate values of ordinary points are formed, and these ordinary points are used to construct spatial lines (such as the centerline, stern closure line, deck edge line, maximum cross-section line, flat bottom line, flat side line, knuckle line, etc.). Then, the spatial lines are modified and optimized to reflect the hull shape characteristics. By using the existing spatial lines and the given offset values of some cross-sections, the cross-section lines at each station of the hull surface are constructed in sequence, and then the cross-section lines are modified and optimized to reflect the hull shape characteristics. By using the existing spatial lines, cross-section lines and the given offset values of some waterlines, the waterlines at different heights of the hull surface are constructed in sequence. According to the fairness of the waterlines, the waterlines are optimized and modified, and the corresponding cross-section lines and spatial lines are synchronously modified. Then, the waterlines are further modified and optimized to reflect the hull shape characteristics. By using the existing spatial lines, cross-section lines, waterlines and the given offset values of some longitudinal section lines, the longitudinal section lines with different widths of the hull surface are constructed in sequence. According to the fairness of the cut longitudinal section lines, the longitudinal section lines are optimized and modified, and the waterlines, longitudinal section lines and spatial lines are synchronously optimized. Based on the existing spatial lines, cross-section lines, waterlines and longitudinal section lines, the lines in the changing area of the hull surface are interpolated and densified, and the relevant lines are synchronously optimized to form a fair three-dimensional wireframe of the hull lines.

[0073] In summary, based on the above point and line categories and different parameter correlation relationships, in the overall design stage, whether it is the preliminary design lines or the three-dimensional modeling of the lines in the case of existing offset values, the lines can be quickly created and optimized. By modifying and fairing the points or lines, the lines related to the point can be synchronously modified, providing a prerequisite for constructing a fair hull surface for the subsequent lines.

[0074] To better understand the present invention, it will be further described below with specific embodiments.

[0075] Embodiment 1, parametric modeling of hull lines:

[0076] Create ordinary points (coordinates X = 0, Y = 0, Z = 0, color 1, symbol 〇) in the software interface;

[0077] Generate a fair curve based on the cutting-in angle (30°), cutting-out angle (45°) and arc radius (5m) of the cross-section line S1;

[0078] Use the intersection point of the waterline WL1000 and the cross-section line S1 as the knuckle point (color 2, symbol ◇);

[0079] Generate the longitudinal section line BL1000 by interpolation and synchronously optimize it with the waterline and cross-section line to form a three-dimensional wireframe.

[0080] Embodiment 2, optimization of hull lines:

[0081] Modify the cutting-in angle of the flat bottom line FBL (adjust from 30° to 40°), and the associated cross-section line is automatically updated;

[0082] Adjust the arc radius of the fold line KN1 (increase from 3 m to 5 m), and the system automatically adjusts the intersection points of adjacent waterlines and longitudinal sections;

[0083] Verify the curvature continuity of the optimized hull lines through a fairness check tool.

[0084] A computer-readable storage medium provided in the second aspect of the present invention stores a computer program, and when the program is executed by a processor, the above method is implemented.

[0085] A ship hull line parameterized modeling system provided in the third aspect of the present invention includes:

[0086] A user interaction module for inputting ship hull line parameters and modification instructions; a data processing module for executing the above method; and a visualization module for real-time display of 3D wireframes and optimization results.

[0087] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A parametric modeling method for ship lines, characterized in that Based on the geometric characteristics of ship lines, the following steps are included: Step S100, classifying point models in three-dimensional modeling and expressing them differently; Step S200, classifying the line model of the hull line and controlling its geometric shape through parameters; Step S300: Based on the classification of the point model and the line model, a correlation control mechanism is established to generate a three-dimensional wireframe by interpolation, smoothing and synchronous optimization of the line.

2. The parametric modeling method for ship lines according to claim 1, characterized in that In step S100, the classification and differential expression of the point model includes: Ordinary points are defined by absolute coordinates and marked with the first color and the first symbol; The knuckle point is located in the knuckle area of ​​the hull line or the transition area of ​​the curved surface and is marked with the second color and the second symbol; Tangent points, points tangent to the arc profile, are marked with the third color and third symbol; Reference points are generated by referencing the intersection of lines or surfaces, including reference points without type values ​​and reference points with type values, and are marked with the fourth color and the fourth symbol.

3. A parametric modeling method for ship hull lines according to claim 1, characterized in that, In step S200, the line model classification includes: Space lines express the boundary characteristics of the hull shape; Transverse section line, the intersection line of the section plane parallel to the mid-station plane and the hull surface; Waterline, the intersection of horizontal planes at different heights with the hull surface; Longitudinal section line is the intersection line of the sectioning plane parallel to the centerline and the hull surface.

4. A parametric modeling method for ship lines according to claim 3, characterized in that In step S300, the relevance control mechanism includes: Define the local curvature characteristics of a single profile by cutting in angle, cutting out angle and arc radius; Establish reference relationships between lines through logical conditions, including intersections within specific ranges and intersections between two lines.

5. A parametric modeling method for ship lines according to claim 4, characterized in that In step S300, a parameter optimization method is also included, including the following steps: Step S301, based on the initial three-dimensional wireframe constructed by the space lines, the space lines and the generated cross-section lines, water lines and longitudinal sections are interpolated, smoothed and synchronously optimized; Step S302, based on the optimized transverse section line, waterline, longitudinal section line and space line, the lines of the hull surface change area are interpolated, created and encrypted, and the relevant lines are optimized simultaneously to form a smooth 3D wireframe of the hull lines.

6. A parametric modeling method for ship lines according to claim 4, characterized in that The logical condition includes at least one of the following forms: Specific range intersection, the position of the reference point is defined by "referenced line name / coordinate axis=value"; The intersection point of two lines is defined by "referenced line A name / referenced line B name".

7. A parametric modeling method for ship lines according to claim 5, characterized in that The smoothing optimization includes: When modifying the entry or exit angle of a single point, the curvature parameters of the associated profile are automatically adjusted; When adjusting the arc radius of the line model, the intersection position of the adjacent waterline and longitudinal section line is updated synchronously; The curvature continuity is checked and the differential modification is performed on the profile that does not meet the set continuity.

8. A parametric modeling method for ship lines according to claim 2, characterized in that The non-type value reference point directly references the intersection of other lines or surfaces without adding a type value parameter; The reference point with type value has type value coordinates added to the reference intersection point, so as to forcibly constrain the shape of the type line.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

10. A parametric modeling system for ship hull lines, characterized in that, include: User interaction module, used to input ship line parameters and modification instructions; A data processing module, configured to execute the method according to any one of claims 1 to 8; Visualization module, used to display 3D wireframe and optimization results in real time.

Images