Engine hood modeling method and related device

Abstract

The embodiment of the invention discloses an engine hood modeling method. The method comprises the steps of determining coordinates of a plurality of feature points of an engine hood modeling surface; the positioning point coordinates of the plurality of positioning points are determined according to the reference point coordinates of the reference point and based on the relative positions of the plurality of positioning points and the reference point, and the positioning point coordinates are relative coordinates of the reference point coordinates; determining a plurality of modeling curve lengths of the engine hood modeling surface according to the coordinates of the plurality of feature points; determining a modeling contour line of the modeling surface of the engine cover in the plurality of modeling curves; according to the modeling contour line, the contour type of the engine hood modeling surface is determined; and modeling the engine hood corresponding to the engine hood modeling surface according to the coordinates of the plurality of feature points of the engine hood modeling surface, the lengths of the plurality of modeling curves and the contour type. The parameters of the modeling surface of the engine hood are represented through the relative relationship among the parameters, so that the modeling surface of the engine hood can be automatically changed according to the established engine hood model during modification, and rapid modeling of the engine hood is realized.

Description

Technical Field

[0001] The present application relates to the technical field of vehicles, and in particular, to a method for modeling an engine hood and related devices. Background Art

[0002] With the diversification of vehicle models, the engine hood of a vehicle, as an important part of vehicle model design, bears the vehicle model and overall appearance functions to meet the market requirements for vehicle models.

[0003] In related technologies, for the modeling of the engine hood of a vehicle, the modeling is mostly based on the shaping surface of the engine hood. The boundary of the engine hood model is defined by the shaping surface of the engine hood, and then the coordinate values corresponding to the feature points are given in the modeling software according to the feature points on the shaping surface. Furthermore, the engine hood is modeled in the modeling software based on the feature points with the given coordinate values.

[0004] However, with the accelerating iteration speed of vehicles, the R & D cycle of the vehicle engine hood is shortened. When the input of the shaping surface of the vehicle engine hood is changed, it is necessary to rebuild the engine hood model, resulting in a large amount of repetitive modeling work, lengthening the R & D cycle of the vehicle engine hood, and not meeting the requirements for rapid modeling of the engine hood. Summary of the Invention

[0005] To solve the above technical problems, the present application provides a method for modeling an engine hood and related devices. By configuring the positional relationships of the feature points on the shaping surface of the engine hood and the length relationships of the curves on the shaping surface of the engine hood, when the shaping surface changes, a new shaping surface can be automatically generated through the positional relationships and length relationships, so as to facilitate rapid modeling of the engine hood through the shaping surface of the engine hood.

[0006] The embodiments of the present application disclose the following technical solutions:

[0007] In a first aspect, the embodiments of the present application disclose a method for modeling an engine hood, and the method includes:

[0008] Determine the coordinates of multiple feature points on the shaping surface of the engine hood; the multiple feature points include a reference point and multiple positioning points, and the positioning point coordinates of the multiple positioning points are determined based on the relative positions of the multiple positioning points and the reference point according to the reference point coordinates of the reference point, and the positioning point coordinates are relative coordinates of the reference point coordinates;

[0009] Determine the shaping curve lengths of multiple shaping curves on the shaping surface of the engine hood according to the coordinates of the multiple feature points;

[0010] Determine the shaping contour line of the shaping surface of the engine hood among the multiple shaping curves;

[0011] Determine the contour type of the shaping surface of the engine hood according to the shaping contour line;

[0012] Model the hood corresponding to the hood styling surface based on the coordinates of multiple feature points, the lengths of multiple styling curves, and the profile types of the hood styling surface to obtain a hood model.

[0013] Optionally, there are at least three of the feature points, and the multiple feature points are not on the same straight line;

[0014] Determining the styling curve lengths of multiple styling curves of the hood styling surface according to the coordinates of the multiple feature points includes:

[0015] Determine a styling coordinate system covering the hood styling surface according to the coordinates of the multiple feature points;

[0016] Determine the styling curve lengths of multiple styling curves of the hood styling surface according to the styling coordinate system.

[0017] Optionally, determining the profile type of the hood styling surface according to the styling contour line includes:

[0018] Determine multiple contour inflection points of the hood styling surface according to the styling contour line;

[0019] Determine the positional relationship between the multiple contour inflection points according to the multiple contour inflection points;

[0020] Determine the profile type of the hood styling surface among multiple preset profile types according to the multiple contour inflection points and the positional relationship.

[0021] Optionally, determining multiple contour inflection points of the hood styling surface according to the styling contour line includes:

[0022] Calculate the first curvature of multiple preset measurement points on the styling contour line according to the styling contour line; multiple of the preset measurement points are pre-arranged on the styling contour line;

[0023] Determine the curvature difference between the first curvature of multiple preset measurement points and the first curvatures of two adjacent preset measurement points among the preset measurement points according to the multiple first curvatures;

[0024] In response to the first curvature being greater than a first curvature threshold and the curvature difference being greater than a first difference threshold, determine the preset measurement point as the contour inflection point.

[0025] Optionally, the method further includes:

[0026] Perform fairing on the styling contour line to obtain a fairing styling contour line;

[0027] Determining the contour type of the hood styling surface according to the styling contour line includes:

[0028] Determining the contour type of the hood styling surface according to the styling fairing contour line.

[0029] Optionally, the method further includes:

[0030] Traversing the model points on the hood model to obtain multiple second curvatures of the multiple model points;

[0031] In response to determining that multiple second curvatures are greater than a second curvature threshold, determining the positions of multiple model points corresponding to the multiple second curvatures among the multiple model points on the hood model;

[0032] Determining a model point region according to the multiple model point positions; the model point region is one or more, and the model point region is a region on the hood model composed of model points adjacent to the model point positions

[0033] Determining the boundary model point coordinates of multiple boundary model points of the adjacent boundary between the model point region and other regions according to the model point region; the other region is the region on the hood model except the model point region;

[0034] Performing interpolation processing on multiple boundary model points.

[0035] Optionally, the hood styling surface is an axisymmetric figure, and the reference point is located on the axis of symmetry of the hood styling surface.

[0036] In a second aspect, an embodiment of the present application discloses a hood modeling device, and the device includes:

[0037] A coordinate determination unit, configured to determine the coordinates of multiple feature points of the hood styling surface; the multiple feature points include a reference point and multiple positioning points, and the positioning point coordinates of the multiple positioning points are determined based on the relative positions of the multiple positioning points and the reference point according to the reference point coordinates of the reference point, and the positioning point coordinates are relative coordinates of the reference point coordinates;

[0038] A curve length determination unit, configured to determine the styling curve lengths of multiple styling curves of the hood styling surface according to the coordinates of the multiple feature points;

[0039] A styling contour line determination unit, configured to determine the styling contour line of the hood styling surface among the multiple styling curves;

[0040] A contour type determination unit, configured to determine the contour type of the hood styling surface according to the styling contour line;

[0041] A modeling unit, configured to model the hood corresponding to the hood styling surface according to the coordinates of multiple feature points, the lengths of multiple styling curves, and the profile types of the hood styling surface, so as to obtain a hood model.

[0042] Optionally, there are at least three of the feature points, and the multiple feature points are not on the same straight line;

[0043] The curve length determination unit is further configured to:

[0044] Determine a styling coordinate system covering the hood styling surface according to the coordinates of the multiple feature points;

[0045] Determine the styling curve lengths of multiple styling curves of the hood styling surface according to the styling coordinate system.

[0046] Optionally, the profile type determination unit is further configured to:

[0047] Determine multiple contour inflection points of the hood styling surface according to the styling contour line;

[0048] Determine the positional relationship between the multiple contour inflection points according to the multiple contour inflection points;

[0049] Determine the profile type of the hood styling surface from multiple preset profile types according to the multiple contour inflection points and the positional relationship.

[0050] Optionally, the profile type determination unit is further configured to:

[0051] Calculate the first curvature of multiple preset measurement points on the styling contour line according to the styling contour line; the multiple preset measurement points are arranged on the styling contour line in advance;

[0052] Determine the curvature difference between the first curvature of the multiple preset measurement points and the first curvature of two adjacent preset measurement points of the preset measurement points according to the multiple first curvatures;

[0053] In response to the first curvature being greater than a first curvature threshold and the curvature difference being greater than a first difference threshold, determine the preset measurement point as the contour inflection point.

[0054] Optionally, the device further includes:

[0055] A fairing processing unit, configured to perform fairing processing on the styling contour line to obtain a fairing styling contour line;

[0056] The profile type determination unit is further configured to:

[0057] Determine the profile type of the hood styling surface according to the fairing styling contour line.

[0058] Optionally, the device further includes:

[0059] A second curvature acquisition unit configured to traverse model points on the hood model to obtain multiple second curvatures of the multiple model points;

[0060] A model point position determination unit configured to, in response to determining that multiple second curvatures are greater than a second curvature threshold, determine the positions of multiple model points corresponding to the multiple second curvatures among the multiple model points on the hood model;

[0061] A model point area determination unit configured to determine a model point area according to the multiple model point positions; the model point area is one or more, and the model point area is an area on the hood model composed of model points adjacent to the model point positions

[0062] A boundary determination unit configured to determine the boundary model point coordinates of multiple boundary model points of an adjacent boundary between the model point area and other areas according to the model point area; the other area is an area on the hood model other than the model point area;

[0063] An interpolation unit configured to perform interpolation processing on the multiple boundary model points.

[0064] Optionally, the hood styling surface is an axisymmetric figure, and the reference point is located on the axis of symmetry of the hood styling surface.

[0065] In a third aspect, an embodiment of the present application discloses a computer device, which includes a processor and a memory:

[0066] The memory is configured to store program code and transmit the program code to the processor;

[0067] The processor is configured to execute the hood modeling method according to the instructions in the program code as described in the first aspect and any optional item of the first aspect.

[0068] In a fourth aspect, an embodiment of the present application discloses a computer-readable storage medium, which is configured to store a computer program, and the computer program is configured to execute the hood modeling method as described in the first aspect and any optional item of the first aspect when executed by a processor.

[0069] As can be seen from the above technical solution, the coordinates of multiple feature points on the hood styling surface are determined; the multiple feature points include a reference point and multiple positioning points, and the positioning point coordinates of the multiple positioning points are determined based on the relative positions of the multiple positioning points and the reference point according to the reference point coordinates of the reference point, and the positioning point coordinates are relative coordinates of the reference point coordinates; according to the coordinates of the multiple feature points, the styling curve lengths of multiple styling curves on the hood styling surface are determined; the styling contour line of the hood styling surface is determined among the multiple styling curves; according to the styling contour line, the contour type of the hood styling surface is determined; according to the coordinates of the multiple feature points on the hood styling surface, the multiple styling curve lengths, and the contour type, the hood corresponding to the hood styling surface is modeled to obtain a hood model. The relative coordinates are used to represent the coordinates of each positioning point on the hood styling surface based on the reference point, and then the styling curve lengths are calculated through the relative relationships between the coordinates. That is to say, the styling curve lengths are also represented in a relative manner, and parameters such as the positioning point coordinates and the styling curve lengths have an associated relationship. When the input of the styling surface of the vehicle hood is changed, only the reference point and the relative position relationship between the reference point and the positioning points need to be changed, and all the parameters of the entire hood styling surface will be changed accordingly, thereby improving the hood modeling speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0071] Figure 1 It is a flowchart of a hood modeling method provided by an embodiment of the present application;

[0072] Figure 2 It is a dimensional marking diagram of a hood styling surface provided by an embodiment of the present application;

[0073] Figure 3 It is a diagram of several preset contour types in a hood modeling method provided by an embodiment of the present application;

[0074] Figure 4 It is a flowchart of a contour type judgment method in a hood modeling method provided by an embodiment of the present application;

[0075] Figure 5 It is a structural block diagram of a hood modeling device provided by an embodiment of the present application;

[0076] Figure 6 It is a structural block diagram of a computer device for hood modeling provided by an embodiment of the present application. Detailed implementation manners

[0077] To enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments.

[0078] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, which is only a way of distinguishing objects with the same attributes when describing the embodiments of this application.

[0079] With the continuous development of vehicle technology, the market's demand for vehicle model diversification is getting higher and higher. Enterprises need to develop new vehicle models in a shorter cycle to seize the market. As an important part of the vehicle model style, the vehicle hood needs to be designed with a variety of vehicle hoods at the design end to meet the market's demand for diversified vehicle models.

[0080] The components of the vehicle hood mainly include an outer panel, an inner panel, a hinge, a reinforcement plate, etc. During the design process of the vehicle hood, the modeling surface of the vehicle hood needs to be input into modeling software such as Computer Aided Design (CAD) to fix the boundary of the hood to be pre-designed. Then, within the fixed boundary, each component of the vehicle hood is modeled to achieve the overall modeling of the hood.

[0081] In the related art, the modeling of the hood is mostly carried out by setting absolute coordinate points. For example, assuming that the coordinates of a certain point on the hood modeling surface are (30, 50), and the coordinates of another point are (60, 50), the distance between the two coordinate points is 30. During the modeling process of the hood, these two points are introduced into the modeling software through the coordinate values, and the distance between the two points is also introduced into the modeling software as a definite length. The same method is used for other coordinate points, straight lines, and curves on the hood modeling surface to complete the modeling of the hood.

[0082] However, this modeling method can only achieve one-time hood modeling for a single hood modeling surface. That is to say, once the hood modeling surface is changed, it is necessary to re-model the hood in the modeling software according to the changed hood modeling surface, resulting in a large amount of repetitive modeling work, reducing the modeling efficiency of the vehicle hood, and affecting the design cycle of the vehicle hood.

[0083] To solve the above technical problems, the present application provides a method for modeling the engine hood of a vehicle. By using the method of representing relative coordinates and relative lengths, based on the relative positions of the reference point and the positioning points, the coordinates of the feature points on the modeling surface of the engine hood and the curve lengths of the modeling curves are represented. When changes occur to the modeling surface of the engine hood, only the feature points where changes occur in the already built engine hood model and the relative positions of the reference point and one or some of the positioning points need to be changed, and the other parts are automatically generated according to the relative coordinates and relative lengths, thereby generating a new engine hood model and improving the modeling efficiency of the vehicle engine hood.

[0084] Next, in conjunction with the accompanying drawings, a method for modeling an engine hood provided by an embodiment of the present application will be introduced.

[0085] Please refer to Figure 2 , Figure 2 which is a dimension marking diagram of the modeling surface of the engine hood provided by an embodiment of the present application. As shown in Figure 2 , it shows the left half of the modeling surface of the engine hood. Its X-axis is the axis of symmetry of the modeling surface of the engine hood, and the Y-axis is the tangent line at the bottom of the modeling surface of the engine hood. In the general modeling process, since the modeling surface of the engine hood is mostly an axisymmetric figure, in order to simplify the modeling process, only the part on one side of the axis of symmetry is modeled, and the part on the other side of the axis of symmetry is directly obtained through the axisymmetric process of the already modeled part. In each of the embodiments shown in the specification of the present application, a method for modeling an engine hood provided by an embodiment of the present application is introduced by modeling one side of the axis of symmetry of the axisymmetric modeling surface of the engine hood. Of course, for the modeling of the engine hood corresponding to the modeling surface of the vehicle engine hood of other regular or irregular figures, this method can also be implemented by modeling the engine hood as a whole according to the overall modeling surface of the engine hood, which will not be elaborated hereinafter.

[0086] Since there are significant differences in the position, size, modeling contour, surface characteristics, etc. of the modeling surface of the engine hood in different vehicle models or different design stages of the same vehicle model, during the modeling process of the engine hood, the above-mentioned various part parameters need to be introduced into the modeling software, and then the modeling of the engine hood is realized based on these parameters.

[0087] Please refer to Figure 1 , Figure 1 which is a flowchart of a method for modeling an engine hood provided by an embodiment of the present application.

[0088] S101: Determine the coordinates of multiple feature points on the modeling surface of the engine hood.

[0089] Among them, the multiple feature points include a reference point and multiple positioning points. The positioning point coordinates of the multiple positioning points are determined based on the relative positions of the multiple positioning points and the reference point according to the reference point coordinates of the reference point, and the positioning point coordinates are the relative coordinates of the reference point coordinates.

[0090] Please combine with Figure 2 , and the intersection points of each solid line marked with black dots in Figure 2 are the feature points of the hood styling surface. The positioning of the hood styling surface can be achieved through multiple feature points. In Figure 2 Among the multiple feature points shown, the lower right corner point, that is, point P, is used as the reference point of the hood styling surface, and the other feature points are the positioning points of the hood styling surface.

[0091] In some possible implementation manners of the embodiments of the present application, for the convenience of calculating the coordinates of the positioning points, a coordinate system can be expanded with point P as the coordinate origin, that is, the coordinates of point P are (Y min , X min ). Extend in the X and Y directions, and the intersection points of these two extension lines with the tangents at the uppermost end and the leftmost end of the hood styling surface are respectively denoted as X max and Y max , that is, the maximum values in the X and Y directions.

[0092] At this time, based on this coordinate system, a certain fixed distance can be used as the unit distance, and the coordinates of each positioning point are relative coordinates given based on the reference point P and the unit distance. For example: assuming the reference distance is a, Figure 2 in the upper right positioning point in , the distance in the X direction from the reference point P is 4a, and the distance in the Y direction is 0, then the coordinates of this positioning point are (0, 4a); the coordinates of other positioning points can also be obtained in the same way, so as to determine the relative coordinates of each positioning point on the hood styling surface in the form of relative coordinates based on the reference point.

[0093] The coordinates of the positioning points are represented by relative coordinates. When one or some of the positioning points change, the previously set relative coordinates can be changed according to the positional relationship between the new positioning point and the positioning point before the change to obtain the new positioning point, so that there is no need to reset the position of the positioning point.

[0094] S102: Determine the lengths of multiple styling curves of the hood styling surface according to the coordinates of multiple feature points.

[0095] Among them, the lengths of the styling curves include the lengths of the curves that can reflect the hood features on the outline and inside of the hood styling surface.

[0096] After the coordinates of the feature points are all determined, the lengths of the styling curves can be obtained from the coordinates of the feature points. Of course, the lengths of the styling curves are also represented in the form of relative lengths. For example, according to Figure 2 shown and the above implementation manners, the lengths of the styling curves can be obtained by mathematical methods such as curve integration according to the coordinate system with point P as the origin and a as the unit distance.

[0097] Of course, the length of the styling curve can also be set relatively according to the relationship between different styling curves. In some possible implementation manners of the embodiment of the present application, during the modeling process of the engine hood, for example, it is necessary to model the lock reinforcement plate and the front beam of the inner panel. Since the lock reinforcement plate is installed inside the front beam of the inner panel, the width of the lock reinforcement plate is directly related to the width of the front beam of the inner panel. If the width of the lock reinforcement plate is W s , and the width of the front beam of the inner panel is W, during the modeling process of a certain engine hood, the relationship between the width of the lock reinforcement plate and the width of the front beam of the inner panel is W s =W - 2. That is to say, when the width of the front beam of the inner panel changes, the width of the lock reinforcement plate also changes accordingly, so as to achieve the matching of the lock reinforcement plate with the changed width of the front beam of the inner panel.

[0098] Similar to the relative coordinates used to represent the positioning point coordinates, the length of the styling curve is represented by a relative length. When a certain part of the engine hood styling surface changes, for example, the position of a certain feature point changes. According to the foregoing, the relative coordinates of this feature point can be quickly changed based on the aforementioned coordinate system, and the related styling curve can also be quickly obtained by using a mathematical method for calculating the curve length based on the coordinates of the changed feature point; for another example, when the size of the entire engine hood styling surface shrinks, the lengths of the various styling curves can also be proportionally reduced according to the shrinking ratio of the engine hood styling surface size, so that when the engine hood styling surface changes, it can be automatically corrected according to the already built engine hood model to obtain a new engine hood model without manual re-modeling.

[0099] S103: Determine the styling contour line of the engine hood styling surface among multiple styling curves.

[0100] Since the modeling of the engine hood is relatively complex and there are many styling curves included in the engine hood, it is necessary to determine the styling contour line among multiple styling curves at this time, so as to determine the specific type of the engine hood styling surface through the styling contour line.

[0101] The styling contour line is the outer contour line of the engine hood styling surface. Similarly, taking Figure 2 as an example, Figure 2 the solid line between the shown feature points is the styling contour line of the engine hood styling surface.

[0102] In some possible implementation manners of this embodiment, the styling contour line of the engine hood styling surface can be extracted through the curve extraction function in the 3D CAD modeling software to obtain the styling contour line.

[0103] S104: Determine the contour type of the engine hood styling surface according to the styling contour line.

[0104] Among them, the contour type is a representation method for the specific shape of the hood styling surface. Please refer to Figure 3 , Figure 3 which are several preset contour type diagrams in a hood modeling method provided by an embodiment of the present application. In some possible implementation manners of the embodiment of the present application, based on the aforementioned obtained feature points and the length of the styling contour line, it is possible to perform matching among the four preset contour types A, B, C, and D shown in Figure 3 to obtain the preset contour type that best matches the current hood styling surface. Of course, the contour type is not limited to these four. For diverse vehicle models, more preset contour types need to be added for use in hood modeling.

[0105] S105: Model the hood corresponding to the hood styling surface based on the coordinates of multiple feature points of the hood styling surface, the lengths of multiple styling curves, and the contour type to obtain a hood model.

[0106] At this point, based on the above-obtained various parameters, the hood styling surface can be introduced into the modeling software, and then the hood can be modeled according to the marked hood styling surface. Of course, in the same manner as above, according to the hood styling surface, other relevant parts of the hood corresponding to the hood styling surface can also be modeled through the modeling software to achieve hood modeling, and the various parameters of the hood are also related by relative numerical values. When a certain part is changed, other related parts can also be quickly changed accordingly.

[0107] In order to provide a targeted method for obtaining feature points for different hood styling surfaces to simplify the calculation of feature point coordinates, based on the above embodiment, further, the feature points are at least three, and the multiple feature points are not on the same straight line;

[0108] The determining of the styling curve lengths of multiple styling curves of the hood styling surface according to the coordinates of the multiple feature points includes:

[0109] Determine a styling coordinate system covering the hood styling surface according to the coordinates of the multiple feature points;

[0110] Determine the styling curve lengths of multiple styling curves of the hood styling surface according to the styling coordinate system.

[0111] In some possible implementation manners of the embodiment of the present application, in combination with Figure 2 , taking the reference point P as the coordinate origin, a coordinate system in the X and Y directions is established, and the styling curve can be obtained according to this coordinate system. In an actual application, through a 3D CAD modeling software such as CATIA software, the extreme points in the X and Y directions of the input styling surface can be obtained and recorded as Y min , Xmin and X max and Y max and respectively construct dimension marking lines in the X and Y directions based on these four extreme points, that is, establish a modeling coordinate system among the four extreme points to ensure that the modeling coordinate system can cover the hood modeling surface. After the modeling coordinate system is determined, the lengths of multiple modeling curves on the hood modeling surface covered by the modeling coordinate system can be obtained according to the modeling coordinate system.

[0112] Through the above method of establishing the coordinate system, different coordinate systems can be established according to different hood modeling surfaces, so as to simplify the calculation of the modeling curve length, improve the calculation speed of the modeling curve length, and enhance the hood modeling efficiency.

[0113] When determining the contour type based on the modeling contour line, the contour type can be determined by using the contour inflection points as features. Based on the above embodiments, further, according to the modeling contour line, determine the contour type of the hood modeling surface, including:

[0114] Determine multiple contour inflection points of the hood modeling surface according to the modeling contour line;

[0115] Determine the positional relationship between multiple contour inflection points according to multiple contour inflection points;

[0116] Determine the contour type of the hood modeling surface among multiple preset contour types according to multiple contour inflection points and the positional relationship.

[0117] Among them, the contour inflection point can be the intersection of different modeling contour lines, or the point where the curvature of the modeling contour line is less than a certain characteristic value.

[0118] Among them, the positional relationship between the contour inflection points can determine the specific shape of the hood modeling surface. Please refer back to Figure 3 , in Figure 3 , for example Figure 3 A has 5 contour inflection points, while Figure 3 B has 4 contour inflection points. The different numbers of their contour inflection points result in different specific shapes of their hood modeling surfaces; for another example Figure 3 C and Figure 3 B also have 4 contour inflection points, but their positional relationships of the contour inflection points are different, which also results in different specific shapes of their hood modeling surfaces. Different hood modeling surfaces correspond to different subsequent hood modeling, and also correspond to different vehicle models during actual vehicle modeling.

[0119] Of course, for the specific shape of the hood modeling surface, when the length or distribution of the modeling contour line is different, there will also be other preset contour types.

[0120] In the process of determining the above-mentioned contour type, it is necessary to first determine the contour inflection points on the modeling contour line. Therefore, in order to obtain the contour inflection points quickly and efficiently, based on the above embodiments, further, according to the modeling contour line, a plurality of contour inflection points of the hood modeling surface are determined, including:

[0121] According to the modeling contour line, calculate the first curvature of a plurality of preset measurement points on the modeling contour line; the plurality of preset measurement points are pre-arranged on the modeling contour line;

[0122] According to the plurality of first curvatures, determine the curvature difference between the plurality of preset measurement points and the first curvatures of two adjacent preset measurement points of the preset measurement points;

[0123] In response to the first curvature being greater than the first curvature threshold and the curvature difference being greater than the first difference threshold, determine the preset measurement point as a contour inflection point.

[0124] In some possible implementation manners of the embodiments of the present application, the preset measurement points may be evenly distributed on the modeling contour line, and the distance may be set to 1 mm. Calculate the first curvature at each preset measurement point. Since the greater the curvature, the greater the degree of bending at this point, and the greater the probability that there are contour inflection points at this point and its neighborhood.

[0125] Furthermore, take the difference between the first curvatures of the preset measurement point and its adjacent preset measurement points to obtain the curvature difference. The greater the curvature difference, that is, the greater the difference in the degree of bending of the preset measurement point compared to the degree of bending of its adjacent preset measurement points. When the difference in the degree of bending of a certain preset measurement point and the degrees of bending of its two adjacent preset measurement points on the left and right is too large, it means that the curves on both sides of the preset measurement point are relatively smooth, and the degree of bending of the preset measurement point is large, thus proving that the preset measurement point is the contour inflection point.

[0126] Regarding the calculation of the curvature and the comparison between the curvature and the curvature threshold, it can be compared by calculating the radius of curvature and setting the radius of curvature threshold. At this time, the smaller the radius of curvature of a certain preset measurement point, the greater the curvature of this point, which also means that the greater the degree of bending at this point, and the more likely this point is a contour inflection point.

[0127] Please refer to Figure 4 , Figure 4 which is a flowchart of a method for judging the contour type in a hood modeling method provided by an embodiment of the present application. This method is based on Figure 3 the four preset contour type diagrams shown. The determined contour types included in the steps respectively correspond to the preset contour type diagrams shown as A, B, C, or D in Figure 3 . This method includes S401 - S414:

[0128] S401: Determine the modeling contour line;

[0129] S402: Smooth the contour line of the shape;

[0130] S403: Arrange n preset measurement points at intervals of 1 mm on the smoothed contour line of the shape;

[0131] S404: Calculate the curvature of each preset measurement point, and successively calculate the curvature difference between two adjacent preset measurement points;

[0132] S405: Mark the points with a curvature difference of 0;

[0133] S406: Determine whether the curvature difference of the preset measurement point is greater than the preset difference threshold; if yes, go to S408; if no, go to S407;

[0134] S407: Determine that this preset measurement point is not an inflection point;

[0135] S408: Determine all preset measurement points with a curvature difference greater than the preset difference threshold as inflection points, and record the number of inflection points; if the number of inflection points is 5, go to S409; if the number of inflection points is 4, go to S410; if the number of inflection points is 3, go to S411;

[0136] S409: Determine the contour type as Type A;

[0137] S410: Calculate the horizontal distance and vertical distance between two inflection points below the hood shape surface;

[0138] S411: Determine the contour type as Type D;

[0139] S412: Determine whether the horizontal distance is greater than the vertical distance; if yes, go to S413; if no, go to S414;

[0140] S413: Determine the contour type as Type B;

[0141] S414: Determine the contour type as Type C.

[0142] Since in the subsequent process of hood modeling, it is necessary to model the inner panel main beam with a roughly same contour trend of the shape contour line, at this time, it is necessary to process the shape contour line so that the shape contour serves as the guiding line for inner panel main beam modeling. Therefore, based on the above embodiments, further, the method further includes:

[0143] Smooth the shape contour line to obtain a smoothed shape contour line;

[0144] Determine the contour type of the hood shape surface according to the shape contour line, including:

[0145] Determine the contour type of the hood shape surface according to the smoothed shape contour line.

[0146] Among them, a fairing curve is a smooth and fluent curve, that is, a curve with a small degree of curvature change, few mutations or curvature jump points.

[0147] In some possible implementation manners of the embodiments of the present application, the styling contour line can be fairing processed through relevant commands of 3D modeling software. For example, the styling contour line can be extracted through the curve extraction command in CATIA software, and then the extracted styling contour line can be fairing processed through the curve smooth command in the dialog box; the styling contour line can also be fairing processed through the fairing command in the Shape module to make the curve fairing.

[0148] By fairing processing the curve, it is convenient for the subsequent inner panel main beam to be modeled based on the hood styling surface.

[0149] To facilitate the inner panel modeling in the subsequent modeling process of the hood, based on the above embodiments, further, the method further includes:

[0150] Traverse the model points on the hood model to obtain multiple second curvatures of multiple model points;

[0151] In response to determining that the multiple second curvatures are greater than the second curvature threshold, determine the multiple model point positions of the multiple model points corresponding to the multiple second curvatures on the hood model;

[0152] According to the multiple model point positions, determine the model point regions; there are one or more model point regions, and the model point regions are regions on the hood model composed of adjacent model points of the model point positions

[0153] According to the model point regions, determine the boundary model point coordinates of multiple boundary model points of the adjacent boundaries between the model point regions and other regions; the other regions are regions on the hood model other than the model point regions;

[0154] Perform interpolation processing on the multiple boundary model points.

[0155] Since when performing inner panel modeling in the hood modeling process, the surface trend of its plate surface needs to be consistent with the hood styling surface, therefore, some edge line features of the hood styling surface need to be processed so that the inner panel can be modeled based on the input hood styling surface in the subsequent hood modeling process. In the traditional technology, engineers need to manually process the hood styling surface through the modeling software, remove the edge line feature regions on the hood model, and then repair the removed parts to make the entire hood model complete.

[0156] However, when modeling the hood through different hood styling surfaces, the surface features of the hood model are all inconsistent, which makes it necessary for engineers to manually process in different ways for different hood styling surfaces, and it is impossible to unify the ridge feature processing method.

[0157] To solve the above technical problems, in the steps of hood modeling in the embodiments of the present application, the ridge feature is eliminated by the method of point cloud reconstruction.

[0158] First, model points are determined on the hood model. In some possible implementation manners, by assigning point cloud data to the model points, the positions of all points on the model can be determined according to the coordinate system established based on the foregoing reference points. Then, curvature analysis is performed on each model point assigned with point cloud data to obtain the second curvature of each model point.

[0159] Among them, the assigned point cloud data can be the serial number marks of each point in the X and Y directions. For example, for a certain model point N, its coordinate in the X direction is X i , and its coordinate in the Y direction is Y j , then the coordinate of this point is (X i , Y j ). Then, relevant commands of 3D modeling software are used. For example, the secondary development technology in CATIA software is used to write a function program for the mathematical method of curvature calculation. Through this function program, multiple model points on the hood model are traversed to calculate the second curvatures of multiple model points.

[0160] Since the ridge feature is mostly a feature on a line rather than a feature of an isolated model point, it is necessary to determine the model point region where the model point is located to obtain the specific position of the ridge feature on the hood model.

[0161] Based on the above implementation manner, after obtaining multiple second curvatures, the model points with the second curvature greater than the second curvature threshold are extracted. Similar to the comparison with the first curvature, here, the curvature radius of the model point can also be compared with a preset curvature radius threshold. For example, the curvature radius threshold can be set to 8 mm. If the curvature radius is less than the curvature radius threshold, it is determined that the curvature of the model point is large. At this time, according to the coordinates located for each model point before, the adjacent model points on the hood model are determined through the coordinates, and then the region composed of the model points with large curvature and adjacent to each other is defined as the model point region, that is, the region with ridge features that needs to be repaired.

[0162] After determining the model point area, it is also necessary to obtain the boundary of the model point area to achieve precise processing of the edge line features. At this time, through the coordinates assigned to the model points above, traverse the located model point area. Specifically, use the modeling software to find the coordinates of the model points with the maximum and minimum values in the X and Y directions in each row and each column of the model point area respectively. For example, for a row in the X direction passing through a located model point area, its Y coordinates are already determined, then find the points with the maximum and minimum coordinates in the X direction on this row in the model point area. These two model points are the boundary model points of the model point area. The method for finding the boundary model points of the model point area for a column in the Y direction is similar to the above method. After the traversal is completed, the boundary line of the model point area can be obtained, which is the dividing line between the model point area and the non-model point area on the hood model.

[0163] After that, interpolation processing is performed on the obtained boundary model points to make the model area blend with the non-model area, thereby removing the edge line features of the model area. In some possible implementation manners of this embodiment, bilinear interpolation operations can be performed on the Y coordinate values of the boundary model points obtained in the X direction, and at the same time, bilinear interpolation operations can be performed on the X coordinate values of the boundary model points obtained in the Y direction. The interpolation can be obtained based on the coordinates of other points adjacent to the boundary model points to combine new coordinate points, and then a new hood modeling surface is reconstructed according to the new coordinate points.

[0164] Through the above method, the processing of the surface features of the hood model can be realized, such as removing the edge line features in the surface features, so that the subsequent inner panel can be modeled based on the hood modeling surface.

[0165] Please refer to Figure 5 , Figure 5 which is a structural block diagram of a hood modeling device provided by an embodiment of the present application. The device includes:

[0166] A coordinate determination unit 510 for determining the coordinates of multiple feature points of the hood modeling surface; the multiple feature points include a reference point and multiple positioning points, and the positioning point coordinates of the multiple positioning points are determined based on the relative positions of the multiple positioning points and the reference point according to the reference point coordinates of the reference point, and the positioning point coordinates are relative coordinates of the reference point coordinates;

[0167] A curve length determination unit 520 for determining the modeling curve lengths of multiple modeling curves of the hood modeling surface according to the coordinates of the multiple feature points;

[0168] A modeling contour line determination unit 530 for determining the modeling contour line of the hood modeling surface among the multiple modeling curves;

[0169] A contour type determination unit 540, configured to determine the contour type of the hood modeling surface according to the modeling contour line;

[0170] A modeling unit 550, configured to model the hood corresponding to the hood modeling surface according to the coordinates of multiple feature points of the hood modeling surface, the lengths of multiple modeling curves, and the contour type, to obtain a hood model.

[0171] As a possible implementation manner, the feature points are at least three, and the multiple feature points are not on the same straight line;

[0172] The curve length determination unit is further configured to:

[0173] Determine a modeling coordinate system covering the hood modeling surface according to the coordinates of the multiple feature points;

[0174] Determine the modeling curve lengths of multiple modeling curves of the hood modeling surface according to the modeling coordinate system.

[0175] As a possible implementation manner, the contour type determination unit is further configured to:

[0176] Determine multiple contour inflection points of the hood modeling surface according to the modeling contour line;

[0177] Determine the positional relationship between the multiple contour inflection points according to the multiple contour inflection points;

[0178] Determine the contour type of the hood modeling surface from multiple preset contour types according to the multiple contour inflection points and the positional relationship.

[0179] As a possible implementation manner, the contour type determination unit is further configured to:

[0180] Calculate the first curvature of multiple preset measurement points on the modeling contour line according to the modeling contour line; the multiple preset measurement points are pre-arranged on the modeling contour line;

[0181] Determine the curvature difference between the first curvature of the multiple preset measurement points and the first curvatures of two preset measurement points adjacent to the preset measurement point according to the multiple first curvatures;

[0182] In response to the first curvature being greater than a first curvature threshold and the curvature difference being greater than a first difference threshold, determine the preset measurement point as the contour inflection point.

[0183] As a possible implementation manner, the device further includes:

[0184] A fairing processing unit for fairing the shaping contour line to obtain a shaped fairing contour line;

[0185] The contour type determination unit is further configured to:

[0186] Determine the contour type of the hood shaping surface according to the shaped fairing contour line.

[0187] As a possible implementation, the device further includes:

[0188] A second curvature acquisition unit for traversing the model points on the hood model to obtain multiple second curvatures of the multiple model points;

[0189] A model point position determination unit for determining the positions of multiple model points corresponding to the multiple second curvatures on the hood model in response to determining that the multiple second curvatures are greater than a second curvature threshold;

[0190] A model point region determination unit for determining a model point region according to the multiple model point positions; the model point region is one or more, and the model point region is a region on the hood model composed of adjacent model points of the model point positions

[0191] A boundary determination unit for determining the boundary model point coordinates of multiple boundary model points of the adjacent boundary between the model point region and other regions according to the model point region; the other region is the region on the hood model except the model point region;

[0192] An interpolation unit for performing interpolation processing on the multiple boundary model points.

[0193] As a possible implementation, the hood shaping surface is an axisymmetric figure, and the reference point is located on the axis of symmetry of the hood shaping surface.

[0194] As can be seen from the above technical solution, the coordinates of multiple feature points on the hood styling surface are determined; the multiple feature points include a reference point and multiple positioning points, and the positioning point coordinates of the multiple positioning points are determined based on the relative positions of the multiple positioning points and the reference point according to the reference point coordinates of the reference point, and the positioning point coordinates are relative coordinates of the reference point coordinates; according to the coordinates of the multiple feature points, the styling curve lengths of multiple styling curves on the hood styling surface are determined; the styling contour line of the hood styling surface is determined from the multiple styling curves; according to the styling contour line, the contour type of the hood styling surface is determined; according to the coordinates of the multiple feature points on the hood styling surface, the multiple styling curve lengths and the contour type, the hood corresponding to the hood styling surface is modeled to obtain a hood model. The relative coordinates are used to represent the coordinates of each positioning point on the hood styling surface based on the reference point, and then the styling curve lengths are calculated through the relative relationships between the coordinates. That is to say, the styling curve lengths are also represented in a relative manner, and parameters such as the positioning point coordinates and the styling curve lengths have an associated relationship. When the input of the styling surface of the vehicle hood is changed, only the reference point and the relative position relationship between the reference point and the positioning points need to be changed, and all the parameters of the entire hood styling surface will be changed accordingly, thereby improving the hood modeling speed.

[0195] Please refer to Figure 6 , Figure 6 which is a structural block diagram of a computer device for hood modeling provided by an embodiment of the present application. The computer device includes a processor 610 and a memory 620:

[0196] The memory 620 is used to store program codes and transmit the program codes to the processor 610;

[0197] The processor 610 is used to execute the hood modeling method as described in any one of the above embodiments according to the instructions in the program codes.

[0198] An embodiment of the present application also discloses a computer-readable storage medium, which is used to store a computer program, and the computer program is used to execute the hood modeling method as described in any one of the above embodiments when executed by a processor.

[0199] It can be understood that this method can be applied to a processing device, which is a processing device capable of performing motion control. For example, it can be a terminal device or a server with motion control functions. This method can be independently executed by a terminal device or a server, or can be applied to a network scenario where a terminal device and a server communicate, and is executed in cooperation with the terminal device and the server. Among them, the terminal device can be a device such as a computer or a mobile phone. The server can be understood as an application server or a Web server. In actual deployment, the server can be an independent server or a cluster server.

[0200] Those of ordinary skill in the art can understand that all or part of the steps for implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps including the above method embodiments; and the foregoing storage medium can be at least one of the following media: read-only memory (abbreviation: ROM), RAM, magnetic disk, or optical disc, etc., various media that can store program codes.

[0201] It should be noted that the various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the device and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple. For the relevant parts, reference can be made to the partial description of the method embodiments. The device and system embodiments described above are only illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0202] As described above, this is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An engine hood modeling method, characterized in that, the method includes: Determine the coordinates of multiple feature points on the modeling surface of the engine hood; the multiple feature points include a reference point and multiple positioning points, and the positioning point coordinates of the multiple positioning points are determined based on the relative positions of the multiple positioning points and the reference point according to the reference point coordinates of the reference point, and the positioning point coordinates are relative coordinates of the reference point coordinates; Determine the modeling curve lengths of multiple modeling curves on the modeling surface of the engine hood according to the coordinates of the multiple feature points; Determine the modeling contour line of the modeling surface of the engine hood among the multiple modeling curves; Determine the contour type of the modeling surface of the engine hood according to the modeling contour line; Model the engine hood corresponding to the modeling surface of the engine hood according to the coordinates of multiple feature points, multiple modeling curve lengths and contour type of the modeling surface of the engine hood to obtain an engine hood model.

2. The method according to claim 1, characterized in that, there are at least three of the feature points, and the multiple feature points are not on the same straight line; The determining the modeling curve lengths of multiple modeling curves on the modeling surface of the engine hood according to the coordinates of the multiple feature points includes: Determine a modeling coordinate system covering the modeling surface of the engine hood according to the coordinates of the multiple feature points; Determine the modeling curve lengths of multiple modeling curves on the modeling surface of the engine hood according to the modeling coordinate system.

3. The method according to claim 1, characterized in that, The determining the contour type of the modeling surface of the engine hood according to the modeling contour line includes: Determine multiple contour inflection points on the modeling surface of the engine hood according to the modeling contour line; Determine the positional relationship between the multiple contour inflection points according to the multiple contour inflection points; Determine the contour type of the modeling surface of the engine hood among multiple preset contour types according to the multiple contour inflection points and the positional relationship.

4. The method according to claim 3, characterized in that, The determining multiple contour inflection points on the modeling surface of the engine hood according to the modeling contour line includes: Calculate the first curvature of multiple preset measurement points on the modeling contour line according to the modeling contour line; multiple of the preset measurement points are arranged on the modeling contour line in advance; Determine the curvature difference between the first curvature of multiple preset measurement points and the first curvature of two adjacent preset measurement points of the preset measurement points according to the multiple first curvatures; In response to the first curvature being greater than a first curvature threshold and the curvature difference being greater than a first difference threshold, determine the preset measurement point as the contour inflection point.

5. The method according to claim 1, characterized in that, the method further includes: Perform fairing on the modeling contour line to obtain a fairing contour line; The determining the contour type of the modeling surface of the engine hood according to the modeling contour line includes: Determine the contour type of the modeling surface of the engine hood according to the fairing contour line.

6. The method according to claim 1, characterized in that, the method further includes: Traverse the model points on the engine hood model to obtain multiple second curvatures of the multiple model points; In response to determining that a plurality of the second curvatures are greater than a second curvature threshold, determine the positions of a plurality of model points corresponding to the plurality of the second curvatures on the hood model; Determine a model point region according to the positions of the plurality of model points; the model point region is one or more, and the model point region is a region on the hood model composed of adjacent model points of the model point positions Determine the boundary model point coordinates of a plurality of boundary model points of an adjacent boundary between the model point region and other regions according to the model point region; the other region is a region on the hood model other than the model point region; Perform interpolation processing on the plurality of boundary model points.

7. The method according to any one of claims 1-6, wherein, The hood styling surface is an axisymmetric figure, and the reference point is located on the axis of symmetry of the hood styling surface.

8. A hood modeling device, wherein, The device includes: A coordinate determination unit for determining the coordinates of a plurality of feature points of the hood styling surface; the plurality of feature points include a reference point and a plurality of positioning points, and the positioning point coordinates of the plurality of positioning points are determined based on the relative positions of the plurality of positioning points and the reference point according to the reference point coordinates of the reference point, and the positioning point coordinates are relative coordinates of the reference point coordinates; A curve length determination unit for determining the styling curve lengths of a plurality of styling curves of the hood styling surface according to the coordinates of the plurality of feature points; A styling contour line determination unit for determining the styling contour line of the hood styling surface among the plurality of styling curves; A contour type determination unit for determining the contour type of the hood styling surface according to the styling contour line; A modeling unit for modeling the hood corresponding to the hood styling surface according to the coordinates of a plurality of feature points, a plurality of styling curve lengths and the contour type of the hood styling surface to obtain a hood model.

9. A computer device, wherein, The computer device includes a processor and a memory: The memory is used for storing program codes and transmitting the program codes to the processor; The processor is used for executing the hood modeling method according to any one of claims 1-7 according to the instructions in the program codes.

10. A computer-readable storage medium, wherein, The computer-readable storage medium is used for storing a computer program, and the computer program is used for executing the hood modeling method according to any one of claims 1-7 when being executed by a processor.

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