A vehicle exterior styling parameter measurement method and system

Abstract

The present application relates to the technical field of vehicle measurement, in particular to a vehicle outer modeling parameter measurement method and system, comprising: extracting the outer contour of the vehicle according to the side view of the vehicle, and cutting the contour points to divide the outer contour into several regions; simplifying the contour points of the regions; calling the corresponding positioning algorithm to position the contour point positions of different preset vehicle positions in the simplified regions, and calculating the angles according to the contour points of the contour point positions to obtain the angles of the preset vehicle parts as the vehicle outer modeling parameters. The present scheme can quickly and accurately measure the vehicle outer modeling parameters, improve the overall efficiency of the aerodynamic simulation process, and reduce the workload of the user.

Description

Technical Field

[0001] This invention relates to the field of vehicle measurement technology, specifically to a method and system for measuring vehicle exterior styling parameters. Background Technology

[0002] The external styling parameters of a car (such as the shape of the front, the angle of the windows, and the design of the rear) directly determine the airflow characteristics on the vehicle's surface. By optimizing these parameters, air resistance (drag) can be reduced, improving the vehicle's aerodynamic performance, thereby reducing energy consumption and increasing driving range. This has a direct impact on the economy of fuel-powered vehicles, the driving range of new energy vehicles, and the acceleration performance of vehicles. Simultaneously, the external styling design significantly affects the distribution of aerodynamic lift and downforce. A well-designed aerodynamic system can improve vehicle stability at high speeds, reduce wind-blown phenomena, and lower the risk of accidents. For example, by optimizing the window and rear design of SUVs, the "vortex shedding" phenomenon can be reduced, thus improving driving stability.

[0003] In numerical wind tunnel calculations, the AI-based intelligent correction process for turbulence model parameters requires vehicle external shape parameters as input for training the AI ​​model. Existing measurements rely on a large number of PID namings, which increases the time of the entire aerodynamic simulation process and creates unnecessary workload for users.

[0004] Therefore, there is an urgent need for a method and system for measuring vehicle exterior styling parameters, which can quickly and accurately measure vehicle exterior styling parameters, improve the overall efficiency of the aerodynamic simulation process, and reduce the workload of users. Summary of the Invention

[0005] One of the objectives of this invention is to provide a method for measuring vehicle exterior styling parameters, which can quickly and accurately measure vehicle exterior styling parameters, improve the overall efficiency of the aerodynamic simulation process, and reduce the workload of users.

[0006] The basic solution provided by this invention is a method for measuring vehicle exterior styling parameters, comprising the following: S2. Based on the side view of the vehicle, extract the outer contour of the vehicle and cut the outer contour into several regions. S3. Simplify the outline points of the region; S4. For different preset vehicle parts in the simplified area, retrieve the corresponding positioning algorithm to locate the contour points of the angle of the preset vehicle part to be measured, and calculate the angle based on the contour points to obtain the angle of the preset vehicle part as a parameter of the vehicle's external shape.

[0007] Furthermore, S2 includes: S201. Convert the side view to a grayscale image and perform noise reduction processing; S202. Perform edge detection on the denoised grayscale image; S203. Convert the grayscale image after edge detection into a binary image; S204. Extract the vehicle's outer contour from the binary image, and cut the outer contour into several regions.

[0008] Furthermore, the edge detection includes: calculating the gradient and gradient direction of each pixel in the denoised grayscale image, and performing linear interpolation comparison in the gradient direction to retain the pixel with the largest gradient intensity.

[0009] Furthermore, in the side view of the vehicle, the front of the vehicle faces left, and the entire vehicle area is evenly divided into four areas using a cross-division method: the first area, the second area, the third area, and the fourth area.

[0010] Furthermore, the preset vehicle parts include one or more of the following: vehicle hood, front windshield, rear windshield, and rear wheel well; wherein the vehicle hood and front windshield are located in the first region; the rear windshield is located in the third region; and the rear wheel well is located in the fourth region.

[0011] Further, S4 includes: for the first region, calculating the slope between each simplified contour point; Take the two contour points in the first region that are closest to the side of the outer contour in the vertical direction that do not intersect as the contour points of the vehicle hood; The contour point with the largest slope is selected as the contour point of the vehicle's windshield.

[0012] Furthermore, S4 also includes: for the third region, determining the outline points of the corresponding vehicle parts according to the vehicle model; If the vehicle model is Sedan, delete the contour points whose adjacent slope difference is greater than the first preset slope threshold, and take the contour point with the largest slope among the remaining contour points as the contour point of the rear windshield. If the vehicle model is Estate, delete the contour points whose relative distance between contour points is less than the first preset relative distance, and take the contour point with the largest slope among the remaining contour points as the contour point of the rear windshield.

[0013] Furthermore, S4 also includes: for the fourth region, deleting contour points whose relative distance between contour points is less than a second preset relative distance, calculating the difference in slope between the contour point and its adjacent contour points, and if the difference is negative, determining that the contour point is the contour point of the wheel rear baffle.

[0014] Furthermore, S4 also includes: calculating the corresponding angle based on the gradient between the contour points of the preset vehicle parts located, using the contour points of the preset vehicle parts as vehicle exterior styling parameters.

[0015] The second objective of this invention is to provide a vehicle exterior styling parameter measurement system that can quickly and accurately measure vehicle exterior styling parameters, improve the overall efficiency of the aerodynamic simulation process, and reduce the workload of users.

[0016] The present invention provides a second basic solution: a vehicle exterior styling parameter measurement system for performing the above-mentioned vehicle exterior styling parameter measurement method.

[0017] Beneficial effects: This solution extracts the outer contour of a vehicle using its side view, thus reducing the measurement time and increasing efficiency. It can also extract the outer contours of multiple vehicles in batches. After extracting the outer contour, the contour points are cut to divide the outer contour into several regions. The contour points in each region are simplified by filtering out interfering points and lines, reducing the number of contour points, and retaining the effective contour points to make them more suitable for subsequent analysis or display, reducing subsequent calculation interference, and improving calculation efficiency and accuracy. For different preset vehicle parts within a simplified region, the corresponding positioning algorithm is retrieved to locate the contour points of the preset vehicle parts to be measured. Angle calculations are then performed based on these contour points to obtain the angles of the preset vehicle parts, which serve as parameters for the vehicle's external shape. This completes the measurement of the vehicle's external shape parameters. Using different positioning algorithms for different preset vehicle parts in different regions allows for more accurate and targeted positioning, quickly determining the contour point positions of the preset vehicle locations and subsequently obtaining the angles. Compared to traditional methods, this solution directly measures vehicle external shape parameters from images, resulting in less time consumption, higher efficiency, and the ability to extract contours from multiple vehicles in batches without requiring additional user effort, effectively reducing user workload.

[0018] In summary, this solution can quickly and accurately measure the external styling parameters of vehicles, improve the overall efficiency of the aerodynamic simulation process, and reduce the workload for users. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating an embodiment of a method for measuring vehicle exterior styling parameters according to the present invention. Figure 2 This is a side view of a vehicle in an embodiment of a method for measuring vehicle exterior styling parameters according to the present invention; Figure 3 This is a schematic diagram of the outer contour extracted in an embodiment of a vehicle external styling parameter measurement method of the present invention; Figure 4 This is a simplified outline view of the vehicle hood and windshield in an embodiment of a vehicle exterior styling parameter measurement method of the present invention. Figure 5 This is a simplified outline of the rear windshield in an embodiment of a vehicle exterior styling parameter measurement method of the present invention. Figure 6 This is a simplified outline of the rear wheel arch of a vehicle in an embodiment of a method for measuring vehicle exterior styling parameters according to the present invention. Figure 7 This is a measurement result diagram from an embodiment of a vehicle exterior styling parameter measurement method according to the present invention. Detailed Implementation

[0020] The following detailed description illustrates the specific implementation method: Example 1 This embodiment is basically as shown in the appendix. Figure 1 As shown: A method for measuring the external styling parameters of a vehicle, including the following: S1. Obtain the side view of the vehicle; the color of the vehicle in the obtained side view must have a color difference from the background color; in this embodiment, STAR CCM+ is used to capture the side view of the vehicle, such as... Figure 2 As shown.

[0021] S2. Based on the side view of the vehicle, extract the outer contour of the vehicle and cut the outer contour into several regions. The specific processing procedure is as follows: S201. Convert the side view to a grayscale image and perform noise reduction processing; wherein the noise reduction processing is as follows: use Gaussian kernel filtering to remove noise points, generate a 3x3 Gaussian kernel matrix, and perform Gaussian blur processing on the processed grayscale image to reduce noise; S202. Perform edge detection on the denoised grayscale image. Edge detection includes: calculating the gradient and gradient direction of each pixel in the denoised grayscale image, and performing linear interpolation comparison in the gradient direction to retain the pixel with the largest gradient intensity, thereby making the edges sharper and clearer. While retaining the real edges of the image, unimportant edge details are removed. S203. Convert the grayscale image after edge detection into a binary image; S204. Extract the vehicle's outer contour from the binary image, such as... Figure 3 As shown, the outer contour is cut to divide the outer contour of the vehicle area into several regions; in this embodiment, the vehicle area is evenly divided into four regions using a cross-shaped division method, namely the first region, the second region, the third region, and the fourth region, which in this embodiment correspond to the upper left region, the lower left region, the upper right region, and the lower right region.

[0022] S3. Simplify the outline points of the region; Specifically, in this embodiment, the Douglas-Peucker algorithm is used to simplify the region contour points; by sorting, sampling, removing off-points, and calculating the median, the contour points are effectively processed to make them more suitable for subsequent analysis or display; the Douglas-Peucker algorithm returns a simplified list of contour points and a list of original contour points.

[0023] Correspondingly, such as Figure 4-6 The figures shown are simplified outlines of the vehicle's hood, windshield, rear windshield, and rear wheel wells. S4. For different preset vehicle parts in the simplified area, retrieve the corresponding positioning algorithm to locate the contour points of the preset vehicle parts to be measured, and calculate the angle based on the contour points to obtain the angle of the preset vehicle parts as the vehicle's external shape parameters. Each area has a corresponding preset vehicle part, i.e., a preset vehicle part, such as the windshield of the vehicle, in the upper left area (first area). However, each area has many contour points, so it is necessary to further locate the position of the angle to be measured. Therefore, the angle position is determined by locating the contour points, and then the angle is calculated. The preset vehicle parts include, but are not limited to, one or more of the following: vehicle hood, windshield, rear windshield, and rear wheel well; wherein the vehicle hood and windshield are located in the first area; the rear windshield is located in the third area; and the rear wheel well is located in the fourth area; in this embodiment, there are no preset vehicle parts in the second area; in other embodiments, preset vehicle parts can be set in each area as needed. Specifically, for the first region, i.e. the upper left region, the slope between each simplified contour point is calculated, such as: k=abs((contour_up_rear[i-1,1] - contour_up_rear[i,1]) / (contour_up_rear[i-1, 0]-contour_up_rear[i,0])); The two contour points closest to the non-intersecting outer contours in the vertical direction within the first region are taken as the positions of the vehicle's hood; that is, the two leftmost contour points of the vehicle are taken as the contour points of the vehicle's hood. And the contour points already used as the positions of the vehicle's hood... Exclude the contour points that have already been used as the location of the vehicle's hood, and take the contour point with the largest slope as the contour point of the vehicle's windshield. For the third region, namely the upper right region, determine the outline points of the corresponding vehicle parts according to the vehicle model; If the vehicle model is a Sedan (fastback model), delete the contour points whose adjacent slope difference is greater than the first preset slope threshold, and take the contour point with the largest slope among the remaining contour points as the contour point of the rear windshield; where the adjacent slope difference is the difference between the slope of the contour point and the previous contour point and the slope of the contour point and the next contour point. For example, the slope between contour point 2, contour point 1 and contour point 2 and the slope between contour point 2 and contour point 3 are the difference, and the difference is calculated in a loop. If the vehicle model is Estate (straight-back model), delete the contour points whose relative distance between contour points is less than the first preset relative distance, and take the contour point with the largest slope among the remaining contour points as the contour point of the rear windshield; where the relative distance between contour points is the distance between contour points. For the fourth region, namely the lower right region, delete contour points whose relative distance between contour points is less than the second preset relative distance, calculate the difference in slope between the contour point and the adjacent contour point, and if the difference is negative, determine that the contour point is the contour point of the wheel rear panel. The positions of the preset vehicle parts (i.e., contour points) are located based on the changes in slope. The corresponding angles are calculated based on the gradient between the contour points of the preset vehicle parts, and are used as vehicle exterior styling parameters. In this embodiment, the positions of the vehicle hood, windshield, rear windshield, and rear wheel arches are located based on the changes in slope between the contour points of the preset vehicle parts. The corresponding angles are calculated based on the slope between the located contour points. For example: degree_rear_glass=np.degrees(np.arctan(k)); Correspondingly, preset angles for vehicle components include: the angle of the hood, the angle of the windshield, the tilt angle of the rear windshield, and the angle of the rear wheel wells. The acquired angles are then compiled into a table and output, such as... Figure 7 As shown.

[0024] This solution can quickly and accurately measure the external shape parameters of vehicles, improve the overall efficiency of the aerodynamic simulation process, and reduce the workload of users.

[0025] This embodiment also provides a vehicle exterior styling parameter measurement system, which employs the above-described vehicle exterior styling parameter measurement method, including: The acquisition module is used to obtain the side view of the vehicle; The measurement module is used to extract the outer contour of the vehicle based on the side view of the vehicle, and cut contour points to divide the outer contour into several regions. It is also used to simplify the outline points of a region; It is also used to locate the contour points of the angle of the preset vehicle part to be measured for different preset vehicle parts in the simplified area by calling the corresponding positioning algorithm, and to calculate the angle based on the contour points to obtain the angle of the preset vehicle part as a parameter of the vehicle's external shape.

[0026] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for measuring vehicle exterior styling parameters, characterized in that, Based on the side view of the vehicle, the outer contour of the vehicle is extracted and cut into several regions, including: in the side view of the vehicle with the front facing left, the entire vehicle area is evenly divided into four regions using the cross division method, namely the first region, the second region, the third region and the fourth region. Simplify the outline points of the region; For different preset vehicle parts in the simplified area, the corresponding positioning algorithm is retrieved to locate the contour points of the angle of the preset vehicle part to be measured, and the angle is calculated based on the contour points to obtain the angle of the preset vehicle part as a parameter of the vehicle's external shape. The preset vehicle parts include one or more of the following: vehicle hood, windshield, rear windshield, and rear wheel well; wherein the vehicle hood and windshield are located in the first region; the rear windshield is located in the third region; and the rear wheel well is located in the fourth region. The step of locating the contour point positions of different preset vehicle parts in the simplified region by calling the corresponding positioning algorithm includes: for the first region, calculating the slope between each contour point; Take the two contour points in the first region that are closest to the side of the outer contour in the vertical direction that do not intersect as the contour points of the vehicle hood; The contour point with the largest slope is taken as the contour point of the windshield; For the third region, determine the outline points of the corresponding vehicle parts based on the vehicle model; If the vehicle model is Sedan, delete the contour points whose adjacent slope difference is greater than the first preset slope threshold, and take the contour point with the largest slope among the remaining contour points as the contour point of the rear windshield. If the vehicle model is Estate, delete the contour points whose relative distance between contour points is less than the first preset relative distance, and take the contour point with the largest slope among the remaining contour points as the contour point of the rear windshield. For the fourth region, delete contour points whose relative distance between them is less than the second preset relative distance, calculate the difference in slope between the contour point and its adjacent contour point, and if the difference is negative, determine that the contour point is the contour point of the vehicle's rear wheel arch.

2. The method for measuring vehicle exterior styling parameters according to claim 1, characterized in that, The process involves extracting the vehicle's outer contour based on its side view, cutting the outer contour, and dividing it into several regions, including: The side view is converted to grayscale and then denoised. Edge detection is performed on the denoised grayscale image; Convert the grayscale image after edge detection into a binary image; Extract the vehicle's outer contour from the binary image, and cut the outer contour into several regions.

3. The method for measuring vehicle exterior styling parameters according to claim 2, characterized in that, The edge detection includes: calculating the gradient and gradient direction of each pixel in the denoised grayscale image, performing linear interpolation comparison in the gradient direction, and retaining the pixel with the largest gradient intensity.

4. The method for measuring vehicle exterior styling parameters according to claim 1, characterized in that, The angle calculation based on the contour points includes: calculating the corresponding angle based on the gradient between the contour points of the preset vehicle parts, using the contour points of the preset vehicle parts as the vehicle exterior styling parameters.

5. A vehicle exterior styling parameter measurement system, characterized in that, The method for measuring vehicle exterior styling parameters according to any one of claims 1-4 includes: The acquisition module is used to obtain the side view of the vehicle; The measurement module is used to extract the outer contour of the vehicle based on the side view of the vehicle, and cut contour points to divide the outer contour into several regions. It is also used to simplify the outline points of a region; It is also used to locate the contour points of the angle of the preset vehicle part to be measured for different preset vehicle parts in the simplified area by calling the corresponding positioning algorithm, and to calculate the angle based on the contour points to obtain the angle of the preset vehicle part as a parameter of the vehicle's external shape.

Images