A design method of a double curvature glass surface of a vehicle door

Abstract

The application discloses a design method for a double-curvature glass surface of a vehicle door and belongs to the technical field of passenger vehicle design. The three-point fitting circle method is adopted to generate an optimized axis of a modeling glass surface, the precision of the generated optimized axis in the intermediate process is improved, the requirement of fitting the glass surface can be met more quickly, and the working efficiency is improved. Meanwhile, the axis iterative optimization method is adopted, and after a model is established, the problems of low working efficiency and low precision caused by manual adjustment of parameters are solved.

Description

Technical Field

[0001] This invention belongs to the field of passenger vehicle design technology, specifically relating to a design method for a double-curvature glass surface of a car door. Background Technology

[0002] In vehicle styling development, the styling department provides a digital model of the vehicle's exterior surface. The curved surface of the door glass is often a double-curvature drum-shaped surface, which cannot meet the engineering requirements for glass lifting.

[0003] In existing engineering practices, most methods involve refitting the shaped surface into a helical surface with equal pitch to ensure no movement relative to the guide rail during glass lifting. The commonly used fitting scheme for the equal pitch helical surface generally involves five steps, as follows:

[0004] (1) First, generate the initial axis of the shaped glass surface; (2) Generate the optimized axis of the shaped glass surface; (3) Generate a spiral line using the optimized axis; (4) Extract the outline and generate a spiral surface using the spiral line; (5) Adjust the optimized axis of the spiral line using parameters so that the spiral surface changes with the parameters and fits the shaped glass surface as closely as possible.

[0005] However, the above method has the following shortcomings:

[0006] 1. The method of generating the optimized axis line of the shaped glass surface using the surface normal intersection method has low accuracy;

[0007] 2. The direction of adjustment of the optimized axis using parameters needs to be determined manually, which is time-consuming and labor-intensive. Summary of the Invention

[0008] The purpose of this invention is to provide a design method for a double-curvature glass surface of a car door. It uses a three-point fitting circle method to generate the optimized axis of the shaped glass surface, which solves the problem of low accuracy in generating the optimized axis of the shaped glass surface using the surface normal intersection method. At the same time, it uses an axis iteration optimization method. After establishing the model, the axis can be continuously optimized to achieve the optimal fit of the glass surface, which solves the problems of low work efficiency and low accuracy caused by manual parameter adjustment.

[0009] This invention is achieved through the following technical solution:

[0010] A method for designing a double-curvature glass surface for a car door, specifically including the following steps:

[0011] Step 1: Extract the front and rear boundary lines of glass surface S1, and take three points on each boundary line;

[0012] Step 2: Use the three-point circle method to fit the initial axis Z1 of the modeling surface;

[0013] Step 3: Establish the normal plane of the axis at the midpoint of the front and rear boundary lines, and project the points on the boundary lines onto this normal plane;

[0014] Step 4: Using the projection points on the normal plane, fit the optimized axis of the modeling surface using the three-point circle method;

[0015] Step 5: Project the upper and lower endpoints of the front and rear boundary lines onto the optimized axis line, connect the projection points with the corresponding endpoints, and measure the angle between the upper and lower connecting lines of the front and rear boundary lines, the distance between the projection points, and the length of the upper and lower connecting lines.

[0016] Step 6: Using the optimized axis as the axis, calculate the helix parameters based on the measurement results from the previous step, and establish helices starting from the upper endpoints of the front and rear boundary lines respectively;

[0017] Step 7: Use the three-point circle method to fit the contour line of the glass surface, and sweep the contour line along the two spiral lines to generate the initial fitted glass surface.

[0018] Step 8: Substitute the optimized axis line into the initial axis line from Step 2 above, and automatically perform Steps 2-7 to obtain the optimized fitted glass surface. Repeat the above steps until the lengths of the upper and lower connecting lines of the front and rear boundaries in Step 5 are equal. The fitted glass surface obtained in Step 7 is the final fitted glass surface.

[0019] Furthermore, in step one, three points are taken on each of the boundary lines, namely the two ends and the middle point of the boundary line.

[0020] Furthermore, step two is detailed as follows:

[0021] Circles are fitted based on three points on the front and back boundary lines respectively, and the center of each circle is generated. The initial axis line is generated by connecting the two center points.

[0022] Furthermore, step three is detailed below:

[0023] Establish the normal plane of the axis line described in step three through the midpoint of the front and rear boundary lines, and simultaneously project the two points on the front and rear boundary lines onto the normal plane respectively.

[0024] Furthermore, step four is detailed below:

[0025] Using two projection points on the front and back boundary lines and the midpoints on the front and back boundary lines respectively, circles are fitted and new circle centers are generated. An optimized axis line is generated by connecting the two new circle center points.

[0026] Furthermore, step five is detailed below:

[0027] Project the upper and lower endpoints of the front and rear boundary lines onto the optimized axis line. Connect the projection points with the corresponding endpoints to obtain two radius lines. Then measure the angle between the two radius lines corresponding to the front and rear boundary lines, the length of the two radius lines, and the distance between the projection points.

[0028] Furthermore, step six is ​​detailed below:

[0029] Using the optimized axis as the helix axis and the upper endpoint of the back boundary line as the starting point, the helix H1 is generated with a pitch of (360° * the distance L7 between the projections of the upper and lower endpoints of the back boundary line onto the optimized axis) / the angle A1 between the two radii corresponding to the back boundary line. Using the optimized axis as the helix axis and the upper endpoint of the front boundary line as the starting point, the helix H2 is generated with a pitch of (360° * the distance L7 between the projections of the upper and lower endpoints of the back boundary line onto the optimized axis) / the angle A1 between the two radii corresponding to the back boundary line.

[0030] Furthermore, step seven is detailed below:

[0031] Take the midpoint of the lower boundary line of the glass surface in step one, fit an arc based on the lower endpoints of the front and rear boundary lines and the midpoint of the lower boundary line, use this arc as the contour line, and use the two spiral lines obtained in step six as guide lines to sweep and generate the fitted glass surface Q1.

[0032] Furthermore, step eight is detailed below:

[0033] Using the optimized axis Z2 as input instead of the initial axis Z1, a new optimized axis Z3 is generated. Then, the new optimized axis Z3 is used as input instead of the optimized axis Z2 to generate the latest optimized axis Z4. This process is repeated iteratively until the lengths of the two radius lines corresponding to the front and rear boundary lines are equal in terms of the required accuracy, i.e., L3 = L4 and L5 = L6. At this point, the glass surface Q1 will follow the parameter optimization accordingly and automatically achieve the best fit with the shaped glass surface S1.

[0034] Furthermore, the deviation between the glass surface Q1 obtained in step eight and the shaped glass surface S1 is within 0.2 mm.

[0035] Compared with the prior art, the advantages of the present invention are as follows:

[0036] The present invention discloses a design method for a double-curvature glass surface of a car door. It uses a three-point fitting circle method to generate the optimized axis of the shaped glass surface, which improves the accuracy of generating the optimized axis in the intermediate process, and can achieve the requirement of fitting the glass surface more quickly, thereby improving work efficiency. At the same time, it adopts an axis iterative optimization method, which solves the problems of low work efficiency and low accuracy caused by manual parameter adjustment after model establishment. Attached Figure Description

[0037] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0038] Figure 1 This is a flowchart illustrating a method for designing a double-curvature glass surface for a car door according to the present invention.

[0039] Figure 2 This is a schematic diagram of step one of the design methods for a double-curvature glass surface of a car door according to the present invention;

[0040] Figure 3 This is a schematic diagram of step two of the design method for a double-curvature glass surface of a car door according to the present invention;

[0041] Figure 4 This is a schematic diagram of step three of the design method for a double-curvature glass surface of a car door according to the present invention;

[0042] Figure 5 This is a schematic diagram of step four of the design method for a double-curvature glass surface of a car door according to the present invention;

[0043] Figure 6 This is a schematic diagram of steps five and six of the design method for a double-curvature glass surface of a car door according to the present invention;

[0044] Figure 7 This is a schematic diagram of step seven of the design method for a double-curvature glass surface of a car door according to the present invention; Detailed Implementation

[0045] To clearly and completely describe the technical solution and its specific working process of the present invention, the specific embodiments of the present invention are as follows, in conjunction with the accompanying drawings:

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0048] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0049] Example 1

[0050] like Figure 1 The diagram shown is a flowchart illustrating a method for designing a double-curvature glass surface for a car door according to this embodiment. The design method specifically includes the following steps:

[0051] Step 1: Extract the front and back boundary lines of the glass surface, and take three points on each boundary line;

[0052] Step 2: Use the three-point circle method to fit the initial axis of the modeling surface;

[0053] Step 3: Establish the normal plane of the axis at the midpoint of the front and rear boundary lines, and project the points on the boundary lines onto this normal plane;

[0054] Step 4: Using the projection points on the normal plane, fit the optimized axis of the modeling surface using the three-point circle method;

[0055] Step 5: Project the upper and lower endpoints of the front and rear boundary lines onto the optimized axis line, connect the projection points with the corresponding endpoints, and measure the angle between the upper and lower connecting lines of the front and rear boundary lines, the distance between the projection points, and the length of the upper and lower connecting lines.

[0056] Step 6: Using the optimized axis as the axis, calculate the helix parameters based on the measurement results from the previous step, and establish helices starting from the upper endpoints of the front and rear boundary lines respectively;

[0057] Step 7: Use the three-point circle method to fit the contour line of the glass surface, and sweep the contour line along the two spiral lines to generate the initial fitted glass surface.

[0058] Step 8: Substitute the optimized axis line into the initial axis line from Step 2 above, and automatically perform Steps 2-7 to obtain the optimized fitted glass surface. Repeat the above steps until the lengths of the upper and lower connecting lines of the front and rear boundaries in Step 5 are equal. The fitted glass surface obtained in Step 7 is the final fitted glass surface.

[0059] Example 2

[0060] This embodiment provides a method for designing a double-curvature glass surface for a vehicle door, which specifically includes the following steps:

[0061] Step 1: Extract the front boundary line L1 and the back boundary line L2 of the glass surface S1, and extract the two endpoints P1, P2 and the midpoint P3 on the front boundary line; similarly, extract the two endpoints P4, P5 and the midpoint P6 on the back boundary line; as shown... Figure 2 As shown.

[0062] Step 2: Fit a circle using points P1, P2, and P3 and generate center C1; fit a circle using points P4, P5, and P6 and generate center C2; and generate the initial axis Z1 based on the line connecting the two center points, as shown below. Figure 3 As shown.

[0063] Step 3: Draw a plane S2 perpendicular to the axis Z1 through point P3; draw a plane S3 perpendicular to the axis Z1 through point P6; project points P1 and P2 onto S2 to obtain projection points TP1 and TP2; project points P4 and P5 onto S3 to obtain projection points TP4 and TP5, as follows. Figure 4 As shown.

[0064] Step 4: Fit a circle using points TP1, TP2, and P3 and generate the center C3; fit a circle using points TP4, TP5, and P6 and generate the center C4; and generate the optimized axis Z2 based on the line connecting the two center points, as shown below. Figure 5 As shown.

[0065] Step 5: Project P1 and P2 onto the optimized axis Z2 to obtain projection points TZ1 and TZ2. Connect these projection points with the corresponding points P1 and P2 to obtain radius lines L3 and L4, respectively. Project P4 and P5 onto the optimized axis Z2 to obtain projection points TZ4 and TZ5. Connect these projection points with the corresponding points P4 and P5 to obtain radius lines L5 and L6, respectively. The length of the line connecting TZ4 and TZ5 is L7, and the angle between the lines connecting radius lines L5 and L6 is A1. Figure 6 As shown.

[0066] Step 6: Using the optimized axis Z2 as the helix axis, starting from P4, and with a helix pitch of 360° x L7 / A1, generate helix H1; using the optimized axis Z2 as the helix axis, starting from P1, and with a helix pitch of 360° x L7 / A1, generate helix H2, as follows. Figure 6 As shown.

[0067] Step 7: Take P7 as the midpoint of the lower boundary line of glass surface S1. Fit an arc L8 based on points P2, P5, and P7. Use L8 as the contour line and H1 and H2 as guide lines to sweep and generate the fitted glass surface Q1. See details. Figure 7 .

[0068] Step 8: Use the optimized axis Z2 to replace the initial axis Z1 as input to generate the optimized axis Z3. Then use the optimized axis Z3 to replace the optimized axis Z2 as input to generate the optimized axis Z4. Iterate and optimize in this way until L3 = L4 and L5 = L6 at the required accuracy. At this time, the glass surface Q1 will follow the parameter optimization accordingly and automatically achieve the best fit with the shaped glass surface S1, with a deviation within 0.2mm. Generally, three iterations are enough to make the radius lines equal at an accuracy of 0.001mm, thus completing the optimization purpose.

[0069] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0070] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0071] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for designing a double-curvature glass surface for a car door, characterized in that, Specifically, the steps include the following: Step 1: Extract the front and rear boundary lines of glass surface S1, and take three points on each boundary line; Step 2: Use the three-point circle method to fit the initial axis Z1 of the modeling surface; Step 3: Establish the normal plane of the axis at the midpoint of the front and rear boundary lines, and project the points on the boundary lines onto this normal plane; Step 4: Using the projection points on the normal plane, fit the optimized axis of the modeling surface using the three-point circle method; Step 5: Project the upper and lower endpoints of the front and rear boundary lines onto the optimized axis line, connect the projection points with the corresponding endpoints, and measure the angle between the upper and lower connecting lines of the front and rear boundary lines, the distance between the projection points, and the length of the upper and lower connecting lines. Step 6: Using the optimized axis as the axis, calculate the helix parameters based on the measurement results from the previous step, and establish helices starting from the upper endpoints of the front and rear boundary lines respectively; Step 7: Use the three-point circle method to fit the contour line of the glass surface, and sweep the contour line along the two spiral lines to generate the initial fitted glass surface. Step 8: Substitute the optimized axis line into the initial axis line from Step 2 above, and automatically perform Steps 2-7 to obtain the optimized fitted glass surface. Repeat the above steps until the lengths of the upper and lower connecting lines of the front and rear boundaries in Step 5 are equal. The fitted glass surface obtained in Step 7 is the final fitted glass surface.

2. The method for designing a double-curvature glass surface for a car door as described in claim 1, characterized in that, In step one, three points are taken on each of the boundary lines, namely the two ends and the middle point of the boundary line.

3. The method for designing a double-curvature glass surface for a car door as described in claim 1, characterized in that, Step two is as follows: Circles are fitted based on three points on the front and back boundary lines respectively, and the center of each circle is generated. The initial axis line is generated by connecting the two center points.

4. The method for designing a double-curvature glass surface for a car door as described in claim 1, characterized in that, Step three is as follows: Establish the normal plane of the axis line described in step three through the midpoint of the front and rear boundary lines, and simultaneously project the two points on the front and rear boundary lines onto the normal plane respectively.

5. The method for designing a double-curvature glass surface for a car door as described in claim 1, characterized in that, Step four is as follows: Using two projection points on the front and back boundary lines and the midpoints on the front and back boundary lines respectively, circles are fitted and new circle centers are generated. An optimized axis line is generated by connecting the two new circle center points.

6. The method for designing a double-curvature glass surface for a car door as described in claim 1, characterized in that, Step five is as follows: Project the upper and lower endpoints of the front and rear boundary lines onto the optimized axis line. Connect the projection points with the corresponding endpoints to obtain two radius lines. Then measure the angle between the two radius lines corresponding to the front and rear boundary lines, the length of the two radius lines, and the distance between the projection points.

7. The method for designing a double-curvature glass surface for a car door as described in claim 1, characterized in that, Step six is ​​as follows: Using the optimized axis as the helix axis and the upper endpoint of the back boundary line as the starting point, the helix H1 is generated with a pitch of (360° * the distance L7 between the projections of the upper and lower endpoints of the back boundary line onto the optimized axis) / the angle A1 between the two radii corresponding to the back boundary line. Using the optimized axis as the helix axis and the upper endpoint of the front boundary line as the starting point, the helix H2 is generated with a pitch of (360° * the distance L7 between the projections of the upper and lower endpoints of the back boundary line onto the optimized axis) / the angle A1 between the two radii corresponding to the back boundary line.

8. The method for designing a double-curvature glass surface for a car door as described in claim 1, characterized in that, Step seven is as follows: Take the midpoint of the lower boundary line of the glass surface in step one, fit an arc based on the lower endpoints of the front and rear boundary lines and the midpoint of the lower boundary line, use this arc as the contour line, and use the two spiral lines obtained in step six as guide lines to sweep and generate the fitted glass surface Q1.

9. The method for designing a double-curvature glass surface for a car door as described in claim 1, characterized in that, Step eight is as follows: Using the optimized axis Z2 as input instead of the initial axis Z1, a new optimized axis Z3 is generated. Then, the new optimized axis Z3 is used as input instead of the optimized axis Z2 to generate the latest optimized axis Z4. This process is repeated iteratively until the lengths of the two radius lines corresponding to the front and rear boundary lines are equal in terms of the required accuracy. At this point, the glass surface Q1 will follow the parameter optimization accordingly and automatically achieve the best fit with the shaped glass surface S1.

10. The method for designing a double-curvature glass surface for a car door as described in claim 9, characterized in that, The deviation between the glass curved surface Q1 obtained in step eight and the shaped glass surface S1 is within 0.2mm.

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