An evaluation method for appearance holes in the automotive design stage

Abstract

The present invention discloses a method for evaluating the appearance holes in the automotive design stage, which includes: collecting the appearance holes of several actual vehicles with different sizes as samples, and screening out the acceptable appearance holes; calculating the area sizes of each acceptable appearance hole, and defining the area range of the acceptable appearance holes; in the 3D digital model of the newly designed vehicle, calculating the area sizes of each appearance hole of the newly designed vehicle; judging whether the area sizes of each appearance hole of the newly designed vehicle all fall within the area range of the acceptable appearance holes. If so, the evaluation of the appearance holes of the newly designed vehicle is qualified. In the design stage of the new vehicle, by calculating the area sizes of the appearance holes of the newly designed vehicle and comparing them with the area range of the acceptable appearance holes obtained through real vehicle analysis, a real vehicle-style visual perception evaluation of the appearance holes of the newly designed vehicle is realized, ensuring the appearance refinement of the newly designed vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle appearance evaluation, and particularly relates to an appearance hole evaluation method for a vehicle during the design stage. Background Art

[0002] With the increasing requirements for the refinement of vehicle appearance, the appearance requirements for vehicle part matching have gradually become more detailed. Due to process and styling limitations, the vehicle appearance is assembled and spliced by multiple parts, and the visible holes generated at the splicing of three or more parts are called appearance holes. As Figure 1 and Figure 2 shown, it is a schematic diagram of an appearance hole generated at the splicing of three parts. As Figure 3 shown, it is a schematic diagram of an appearance hole generated at the splicing of four parts.

[0003] The holes formed by the splicing between vehicle appearance sheet metal parts and decorative parts are irregular. In the prior art, there is a lack of a technical solution for evaluating the size of appearance holes, so there is no effective evaluation method. Even in the design stage, the evaluation cannot be carried out, resulting in the neglect of the evaluation of the size of appearance holes during vehicle design. Eventually, the appearance holes of the actual vehicle are too large, the visual perception quality is poor, seriously affecting the refinement of the vehicle appearance and the first impression on consumers. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an appearance hole evaluation method for a vehicle during the design stage, which evaluates the appearance holes of a newly designed vehicle during the design and development stage, so that the area size of the appearance holes is within an acceptable range, and the appearance refinement of the newly designed vehicle is ensured.

[0005] To solve the above technical problem, the present invention provides an appearance hole evaluation method for a vehicle during the design stage, including the following steps:

[0006] Step 1: Collect the appearance holes of several actual vehicles with different sizes as samples, and screen out the acceptable appearance holes;

[0007] Step 2: Calculate the area sizes of the acceptable appearance holes, and delimit the acceptable appearance hole area range;

[0008] Step 3: In the 3D digital model of the newly designed vehicle, calculate the area sizes of the appearance holes of the newly designed vehicle;

[0009] Step 4: Judge whether the area sizes of the appearance holes of the newly designed vehicle all fall within the acceptable appearance hole area range. If so, the appearance hole evaluation of the newly designed vehicle is qualified; if not, the appearance hole evaluation of the newly designed vehicle is unqualified.

[0010] Preferably, in step one, the method for screening acceptable appearance holes includes two ways: manual inspection and instrument inspection. Manual inspection can be carried out by visual inspection or using inspection tools. In addition, the main body of manual inspection is several randomly selected people, and the number of selected people is not less than one hundred. By having multiple people conduct manual inspection on the same sample, the screening result will be more reasonable. Instrument inspection can adopt a set program and use technologies such as machine vision to sort the appearance holes of the actual vehicle.

[0011] In the above-mentioned appearance hole evaluation method in the automotive design stage, by detecting the appearance holes of different area sizes of the actual vehicle, the range of the area size of the appearance holes acceptable to customers is obtained. Then, in the design stage of the new vehicle, by calculating the area size of the appearance holes of the newly designed vehicle and comparing it with the acceptable range of the appearance hole area, the detection of the appearance holes of the newly designed vehicle is realized, that is, the real vehicle type evaluation is realized. The evaluation is reasonable and accurate. In addition, when the evaluation result is unqualified, the design data can be revised and the improvement plan can be formulated in time, reducing the phenomenon of excessive appearance holes in the later actual vehicle stage, thus saving the cycle and cost of vehicle model development and making the vehicle appearance more delicate.

[0012] As an improvement of the appearance hole evaluation method in the automotive design stage of the present invention, in step three, the method for calculating the area size of the appearance holes of the newly designed vehicle includes the following steps:

[0013] On the same plane, obtain the contour edges of each part at the splicing position.

[0014] Determine the part of each contour edge that forms the appearance hole, and set the two end points of this part as two boundary points.

[0015] Connect the boundary points on two adjacent contour edges in pairs, and enclose a closed appearance hole surface with the contour edges.

[0016] Calculate the area of the appearance hole surface, which is the area size of the appearance hole.

[0017] By making the contour edges of the splicing positions of the parts that form a certain appearance hole on the same plane, and then using the area of the region enclosed by the connection of the boundary points and the contour edges to approximately replace the area of the appearance hole, the complex calculation caused by the irregularity of the appearance hole is simplified, saving the time for analysis and evaluation. In addition, in the 3D design software, the area of the region enclosed by the contour edges can be directly obtained by the software.

[0018] Generally, on the exterior surface of a vehicle, most exterior parts are not absolute planes but have a certain curvature, making the vehicle body more aesthetically pleasing and having better aerodynamics. In the present invention, when analyzing a certain exterior hole, the surfaces at the joints of the parts that are not planes are approximately regarded as a plane for approximate substitution, that is, the parts have a surface plane or an approximate surface plane at the joints. And generally, the joints of the parts forming the same exterior hole basically have a common surface plane or an approximate common surface plane to ensure the flatness of the vehicle's appearance.

[0019] Further, the method for obtaining the contour edges of the parts at their joints on the same plane includes: the section method: make a section, intercept the side surfaces of the joints of the parts forming the exterior hole, and the section edges of the parts on the section are the corresponding contour edges of the parts.

[0020] The contour edges forming the exterior hole are obtained by the section intercepting method. The section is the above-mentioned plane, generally selecting the common surface plane or the approximate common surface plane at the joints of the parts, and then offsetting a certain distance so that it can penetrate through the side surfaces of the joints of the parts, that is, the section contours of the side surfaces of the joints of the parts can be left on the section, which are the corresponding contour edges. On 3D software, the operation is simple and fast, the section is easy to obtain, and the calculation is convenient. Preferably, the section is a plane perpendicular to the height direction of the exterior hole or a plane parallel to the bottom surface of the exterior hole, making the contour edges intercepted by the section more representative and the calculation result closer to the area size of the exterior hole.

[0021] Further, the method for obtaining the contour edges of the parts at their joints on the same plane includes: the projection method: take a projection plane, project the joints of the parts forming the exterior hole onto the projection plane, and the projection edges of the side surfaces of the joints of the parts are the corresponding contour edges of the parts.

[0022] The contour edges forming the exterior hole are obtained by the projection method. The projection plane is the above-mentioned plane, and generally, the common surface plane or the approximate common surface plane at the joints of the parts is also selected. Preferably, the projection plane is a plane perpendicular to the height direction of the exterior hole or a plane parallel to the bottom surface of the exterior hole, making the contour edges on the projection plane more representative and the calculation result closer to the area size of the exterior hole.

[0023] Furthermore, determine the part with the largest surface area among the parts forming the exterior hole, and the section or the projection plane is parallel to the surface plane or the approximate surface plane at the joint of the part with the largest surface area.

[0024] By analyzing and calculating the appearance hole area by using the flat surface or approximate flat surface of the part with the largest surface area, since when people subjectively evaluate the appearance of a vehicle, they are more sensitive to larger appearance surfaces, the analysis result based on the flat surface of this largest surface part is more representative, and the evaluation result is more practically significant.

[0025] Further, the determining the part on each contour line that forms the appearance hole and setting the two end points of this part as two boundary points includes:

[0026] If there is a process fillet on the side of the part joint where the appearance hole is formed, extract the two end points corresponding to the process fillet part on the contour line as the boundary points of the corresponding contour line;

[0027] If there is no process fillet on the side of the part joint where the appearance hole is formed, take two points on the contour line of this part on both sides of the appearance hole, so that the distances from these two points to the nearest boundary point on the adjacent part are the shortest, and take these two points as the boundary points of the corresponding contour line.

[0028] Since process fillets are mostly designed at the joints of parts, and process fillets are also the main part of forming appearance holes, using process fillets to determine boundary points can fully enclose the area of appearance holes, and it is simple and quick to use; since there must be at least two parts with process fillets for an appearance hole, for parts without process fillets, it is only necessary to set their own boundary points relying on the boundary points of other adjacent parts.

[0029] Further, the connecting the boundary points on two adjacent contour lines in pairs and enclosing with the contour lines to form a closed appearance hole surface includes:

[0030] According to the principle of the largest area, connect the boundary points on two adjacent contour lines in pairs in sequence, and enclose with the contour lines to form a closed appearance hole surface. When connecting the boundary points, the boundary points are in pairs, each contour line has two boundary points as endpoints, one endpoint is connected to the boundary point corresponding to the adjacent contour line, and the other endpoint is connected to the boundary point corresponding to the other adjacent contour line to form a closed graphic area.

[0031] As another improvement of the appearance hole evaluation method in the vehicle design stage of the present invention, before step two, it also includes: obtaining the 3D digital model of the acceptable appearance hole, so that the same method can be used to calculate the area size of the appearance hole in step two and step three. Although the shape of the appearance hole is irregular, the calculation method is the same, making the acceptable appearance hole area range obtained in step two have higher reference significance for the newly designed vehicle in subsequent step three.

[0032] Furthermore, the method for obtaining the three-dimensional digital model of the acceptable appearance hole includes:

[0033] Use laser scanning to scan the acceptable appearance holes on the actual vehicle to obtain point cloud data;

[0034] Convert the point cloud data into a three-dimensional digital model of the corresponding acceptable appearance hole. By using the method of laser scanning to obtain the appearance holes of the actual vehicle, and then obtaining the three-dimensional digital model of the corresponding appearance holes, and then using the above calculation method for analysis to obtain the area of the appearance holes.

[0035] As another improvement of the appearance hole evaluation method in the automobile design stage of the present invention, the number of parts constituting the appearance hole is at least three. As the number of parts constituting the appearance hole increases, the corresponding range of acceptable appearance hole area becomes larger. The appearance holes of the vehicle are generally formed by splicing three parts, but there are also those formed by four parts. As the number of parts increases, the visual impact of the appearance holes on people decreases, so the range of acceptable appearance hole area becomes larger. In addition, as the number of parts increases, the manufacturing difficulty increases, and the fitting error of the parts also increases. Therefore, a larger splicing allowance is also required, that is, a larger range of acceptable appearance hole area.

[0036] In summary, by using the above appearance hole evaluation method in the automobile design stage, in the vehicle design and development stage, the area of the appearance holes formed by the fitting of the body appearance parts can be calculated, and whether it is acceptable on the actual vehicle can be evaluated, and the revision of the design data and the formulation of the improvement plan can be made in a timely manner, reducing the improvement of product mold repair, design change, etc. due to the defect of too large appearance holes in the later actual vehicle stage, thereby saving the cycle and cost of vehicle model development and ensuring the delicacy of the vehicle appearance. Description of the Drawings

[0037] In the drawings:

[0038] Figure 1 It is a schematic structural diagram of an appearance hole formed by three parts.

[0039] Figure 2 It is another schematic structural diagram of an appearance hole formed by three parts.

[0040] Figure 3 It is a schematic structural diagram of an appearance hole formed by four parts.

[0041] Figure 4 It is a schematic cross-section diagram when calculating the area of the appearance hole by the cross-section method of the present invention.

[0042] Figure 5 It is a schematic projection plane diagram when calculating the area of the appearance hole by the projection method of the present invention.

[0043] In the figure, 1, appearance hole surface; 2, boundary point; 3, contour edge Specific embodiments

[0044] The following further describes the specific embodiments of the present invention in conjunction with the accompanying drawings. It should be noted here that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation to the present invention.

[0045] Embodiment 1

[0046] A method for evaluating the appearance holes in the automotive design stage of the present invention includes the following steps:

[0047] Step S10: Collect the appearance holes of several actual vehicles of different sizes as samples, and screen out acceptable appearance holes.

[0048] Optionally, the method for screening out acceptable appearance holes includes two methods: manual detection and instrument detection. Manual detection can be carried out by manual visual inspection and manual gauges. Manual visual inspection directly uses the human eye for observation and visual perception evaluation. Manual gauges can use calipers, special go / no-go gauges, etc. for detection and screening. In addition, the main body of manual detection is several randomly selected people, and the number of selected people is not less than one hundred. By multiple people performing manual detection on the same sample, the screening results are more reasonable. Instrument detection can use a set program and machine vision and other technologies to sort the appearance holes of actual vehicles. On the actual vehicle, directly perform manual detection and evaluation to obtain a sample group of appearance holes acceptable to customers.

[0049] Step S15: Obtain the 3D digital model of the acceptable appearance holes to prepare for calculating the area size of the appearance holes in step S20. The same calculation method on the 3D digital model as in step S30 can be used, so that the acceptable appearance hole area range obtained in step two has higher reference significance for the newly designed vehicle in step three.

[0050] The specific steps for obtaining the 3D digital model of the appearance holes of the actual vehicle are as follows: Use laser scanning to scan the acceptable appearance holes on the actual vehicle to obtain point cloud data; convert the point cloud data into the 3D digital model corresponding to the acceptable appearance holes. Using laser scanning to obtain the appearance holes of the actual vehicle and then obtain the 3D digital model is efficient and fast.

[0051] Step S20: Calculate the area size of each acceptable appearance hole and delimit the acceptable appearance hole area range. If the sample data of the appearance holes of the actual vehicle of different sizes collected is sufficient, the acceptable appearance hole area range can be obtained through the sample group of appearance holes acceptable to customers. Use the maximum value in the sample as the upper limit of the acceptable appearance hole area range, and the lower limit is zero.

[0052] Generally, there are at least three parts that form the appearance holes. As the number of parts forming the appearance holes increases, the corresponding acceptable area range of the appearance holes becomes larger. This is because as the number of parts increases, the visual impact of the appearance holes on people decreases, so the acceptable area range of the appearance holes becomes larger. In addition, as the number of parts increases, the manufacturing difficulty increases and the fitting error of the parts also increases. Therefore, a larger splicing allowance, that is, a larger acceptable area range of the appearance holes, is also required.

[0053] Step S30: In the 3D digital model of the newly designed vehicle, calculate the area sizes of the respective appearance holes of the newly designed vehicle. Analyze the area of the appearance holes at the new vehicle design stage to discover problems as early as possible and make improvements.

[0054] On the appearance surface of the vehicle, most of the appearance parts are not absolute planes but have a certain curvature, making the vehicle body more beautiful and having better streamline. In the present invention, when analyzing a certain appearance hole, the splicing surfaces of the parts that are not planes are approximately regarded as a plane for approximate substitution, that is, the parts have a surface plane or an approximate surface plane at the splicing. And generally, the splicing joints of the respective parts forming the same appearance hole basically have a common surface plane or an approximate common surface plane to ensure the flatness of the vehicle appearance.

[0055] The method for calculating the area on the digital model of the appearance hole includes the following steps:

[0056] Step a: On the same plane, obtain the contour edges of the respective parts at the splicing, including the following two methods:

[0057] ① Section method: Make a section to intercept the side surfaces of the splicing of the respective parts forming the appearance hole. The section edges of the respective parts on the section are the corresponding contour edges of the parts.

[0058] Obtain the contour edges forming the appearance hole through the section intercepting method. The section is the above-mentioned plane. Generally, select the common surface plane or the approximate common surface plane of the splicing of the respective parts, and then offset a certain distance so that it can penetrate through the side surfaces of the splicing of the respective parts, that is, the section contours of the side surfaces of the splicing of the respective parts can be left on the section, which are the corresponding contour edges. This method is simple and fast to operate on 3D software, easy to obtain the section, and convenient for calculation.

[0059] ② Projection method: Take a projection plane and project the splicing of the respective parts forming the appearance hole onto this projection plane. The projection edges of the side surfaces of the splicing of the respective parts are the corresponding contour edges of the parts.

[0060] The contour edges forming the appearance hole are obtained by the projection method. The projection plane is the above-mentioned plane, and the projection plane is generally selected as the common surface plane or approximate common surface plane at the joint of each part.

[0061] Optionally, the cross-section or the projection plane can also be a plane perpendicular to the height direction of the appearance hole or a plane parallel to the bottom surface of the appearance hole, so that the contour edges on the projection plane are more representative and the calculation result is closer to the area size of the appearance hole.

[0062] In addition, determine the part with the largest surface area among the parts forming the appearance hole, and the cross-section or the projection plane is parallel to the surface plane or approximate surface plane at the joint of the part with the largest surface area. Analyze and calculate the area of the appearance hole using the surface plane or approximate surface plane at the joint of the part with the largest surface area. Since when people subjectively evaluate the appearance of a vehicle, they are more sensitive to larger appearance surfaces, the analysis result based on the surface plane of this largest surface part is more representative and the evaluation result is more meaningful in reality.

[0063] Step b: Determine the part of each contour edge used to form the appearance hole, and set the two endpoints of this part as two boundary points. Specifically, it includes:

[0064] ① If there is a process fillet on the side of the joint of the parts forming the appearance hole, extract the two endpoints corresponding to the process fillet part on the contour edge as the boundary points of the corresponding contour edge;

[0065] ② If there is no process fillet on the side of the joint of the parts forming the appearance hole, take two points on the contour edge of this part on both sides of the appearance hole, so that the distances from these two points to the nearest boundary point on the adjacent part are the shortest, and take these two points as the boundary points of the corresponding contour edge.

[0066] Since process fillets are mostly designed at the joints of parts, and process fillets are also the main part forming the appearance hole, using process fillets to determine boundary points can fully enclose the area of the appearance hole, and it is simple and quick to use; since there must be at least two parts with process fillets for an appearance hole, for parts without process fillets, set their own boundary points relying on the boundary points of other adjacent parts.

[0067] Step c: Connect the boundary points on two adjacent contour edges in pairs, and enclose with the contour edges to form a closed appearance hole surface;

[0068] According to the principle of the largest area, the boundary points on two adjacent contour edges are sequentially connected in pairs, and a closed appearance hole surface is formed by enclosing with the contour edges. When connecting the boundary points, the boundary points are paired one by one. Each contour edge has two boundary points as endpoints. One endpoint is connected to the corresponding boundary point of the adjacent contour edge, and the other endpoint is connected to the corresponding boundary point of another adjacent contour edge to form a closed graphic area.

[0069] Step d: Calculate the area of the appearance hole surface, which is the area size of the appearance hole.

[0070] Step S40: Determine whether the area sizes of the appearance holes of the newly designed vehicle all fall within the acceptable range of the appearance hole area. If so, the evaluation of the appearance holes of the newly designed vehicle is qualified; if not, the evaluation of the appearance holes of the newly designed vehicle is unqualified.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the scope of its protection. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that after reading the present invention, various changes, modifications or equivalent replacements can still be made to the specific implementation manners of the invention, but these changes, modifications or equivalent replacements are all within the scope of the protection of the pending claims of the invention.

Claims

1. An evaluation method for the appearance holes in the automotive design stage, characterized in that It includes the following steps: Step 1: Collect the appearance holes of actual vehicles of several different sizes as samples, and screen out the acceptable appearance holes; Step 2: Calculate the area sizes of the acceptable appearance holes, and delimit the area range of the acceptable appearance holes; Step 3: In the 3D digital model of the newly designed vehicle, calculate the area sizes of the appearance holes of the newly designed vehicle; Step 4: Judge whether the area sizes of the appearance holes of the newly designed vehicle all fall within the area range of the acceptable appearance holes. If so, the evaluation of the appearance holes of the newly designed vehicle is qualified; if not, the evaluation of the appearance holes of the newly designed vehicle is unqualified; In Step 3, the method for calculating the area sizes of the appearance holes of the newly designed vehicle includes the following steps: On the same plane, obtain the contour edges of each part at the splicing position; Determine the part of each contour edge that forms the appearance hole, and set the two end points of this part as two boundary points; Connect the boundary points on two adjacent contour edges in pairs, and enclose with the contour edges to form a closed appearance hole surface; Calculate the area of the appearance hole surface, which is the area size of the appearance hole; The determining the part of each contour edge that forms the appearance hole and setting the two end points of this part as two boundary points includes: If there is a process fillet on the side of the part splicing position that forms the appearance hole, extract the two end points corresponding to the process fillet part on the contour edge as the boundary points of the corresponding contour edge; If there is no process fillet on the side of the part splicing position that forms the appearance hole, take two points on the contour edge of the part on both sides of the appearance hole, so that the distances from these two points to the nearest boundary point on the adjacent part are the shortest, and take these two points as the boundary points of the corresponding contour edge.

2. The appearance hole evaluation method in the automotive design stage according to claim 1, characterized in that The method for obtaining the contour edges of each part at the splicing position on the same plane includes: Section method: Make a section, intercept the side of the splicing position of each part that forms the appearance hole, and the section edges of each part on the section are the contour edges of the corresponding parts; Or Projection method: Take a projection plane, project the splicing position of each part that forms the appearance hole onto this projection plane, and the projection edges of the side of the splicing position of each part are the contour edges of the corresponding parts.

3. The appearance hole evaluation method in the automotive design stage according to claim 2, wherein Determine the part with the largest surface area among the parts that form the appearance hole, and the section or the projection plane is parallel to the surface plane or approximate surface plane of the splicing position of the part with the largest surface area.

4. A method for evaluating the appearance holes in the automotive design stage according to claim 1, characterized in that The connecting the boundary points on two adjacent contour edges in pairs and enclosing with the contour edges to form a closed appearance hole surface includes: According to the principle of the largest area, connect the boundary points on two adjacent contour edges in pairs in sequence, and enclose with the contour edges to form a closed appearance hole surface.

5. The appearance hole evaluation method in the automotive design stage according to claim 1, wherein, Before Step 2, it also includes: Obtaining the 3D digital model of the acceptable appearance hole.

6. The appearance hole evaluation method in the automotive design stage according to claim 5, characterized in that, The method for obtaining the 3D digital model of the acceptable appearance hole includes: Use laser to scan the acceptable appearance holes on the actual vehicle to obtain point cloud data; Convert the point cloud data into the 3D digital model corresponding to the acceptable appearance hole.

7. A method for evaluating the appearance holes in the automotive design stage according to claim 1, characterized in that In Step 1, the method for screening out the acceptable appearance holes includes two screening methods: manual detection and instrument detection.

8. The appearance hole evaluation method in the automotive design stage according to claim 1, wherein The number of parts forming the appearance holes is at least three. As the number of parts forming the appearance holes increases, the corresponding acceptable area range of the appearance holes becomes larger.

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