A design method, device, medium, and drone lip for an unmanned aerial vehicle (UAV).

Abstract

The present invention discloses a design method, device, medium and UAV for the lip of a UAV. The method can obtain the structure of the UAV air inlet entrance, the cabin structure and the aerodynamic requirements of the air inlet, and can determine the Bezier curves of the inner lip and the outer lip respectively on the basis of meeting the aerodynamic performance requirements. This curve can flexibly adjust the shape of the lip, and then generate the profile of the lip along the cross section, and determine the relative position of the lip and the air inlet entrance according to these profiles. In this way, the geometric shape of the lip, especially the thickness and length of the lip, can be accurately controlled, so as to effectively deal with the aerodynamic separation problem caused by the air inlet being installed at the rear of the fuselage; especially the lip far away from the side of the fuselage, through the design of the Bezier curve, its incoming flow angle and aerodynamic characteristics can be optimized, and the aerodynamic separation phenomenon can be reduced, thereby improving the overall performance of the air inlet and the working efficiency of the entire propulsion system.

Description

Technical Field

[0001] The present invention relates to the field of aircraft design, and in particular to a design method, device, medium and unmanned aerial vehicle (UAV) lip. Background Art

[0002] Drones are increasingly being used in a wide range of fields due to their unique advantages such as low cost, low damage, zero casualties, non-contact and high maneuverability. In particular, high-subsonic drones powered by jet engines have become the focus of development in various countries. As the "heart" of drones, jet engines determine their key performance and flight quality.

[0003] The lip of the air inlet is the front end of the UAV's power system, and its design directly affects the performance of the air inlet and the efficiency of the entire propulsion system. Therefore, it is crucial to develop a reliable lip design method. Since the air inlet of a medium- and high-speed UAV is usually installed at the rear of the fuselage, the airflow is guided by the fuselage, resulting in a smaller flow angle at the lip close to the fuselage than at the lip far from the fuselage, which easily causes aerodynamic separation at the lip far from the fuselage.

[0004] Therefore, in order to improve the air intake performance of UAVs, a parametric design method for the variable thickness air intake lip is urgently needed. Summary of the invention

[0005] The purpose of the present invention is to provide a design method, device, medium and drone for the lip of a drone, which can accurately control the geometric shape of the lip, especially the thickness and length of the lip, so as to effectively deal with the aerodynamic separation problem caused by the installation of the air inlet on the rear part of the fuselage; especially the lip away from the side of the fuselage, through the design of Bezier curve, its incoming flow angle and aerodynamic characteristics can be optimized, the aerodynamic separation phenomenon can be reduced, and then the overall performance of the air inlet and the working efficiency of the entire propulsion system can be improved.

[0006] On the one hand, the present application provides a method for designing a lip of a drone, comprising: obtaining an inlet structure of an air inlet of a drone and a cabin structure of the drone; obtaining aerodynamic requirements of the air inlet; determining a first Bezier curve corresponding to an inner lip and a second Bezier curve corresponding to an outer lip according to the aerodynamic requirements, the inlet structure and the cabin structure, wherein the lip of the drone includes the inner lip and the outer lip; determining a profile of a cross-section along the lip according to the first Bezier curve and the second Bezier curve, and determining a relative position of the lip and the air inlet according to the profile of the cross-section along the lip to achieve the design of the lip.

[0007] Optionally, obtaining the inlet structure of the air inlet inlet of the UAV includes: obtaining a cross-sectional curve of the air inlet inlet of the UAV; after obtaining the inlet structure of the air inlet inlet of the UAV, further including: discretizing the cross-sectional curve to obtain a plurality of discrete points corresponding to the cross-sectional curve; determining the position coordinates of each of the discrete points; and determining a first Bezier curve corresponding to the inner lip according to the aerodynamic requirements, the inlet structure and the cabin structure, including: determining the first Bezier curve corresponding to the inner lip according to the aerodynamic requirements and the position coordinates of each of the discrete points.

[0008] Optionally, determining a first Bezier curve corresponding to the inner lip according to the aerodynamic requirements and the position coordinates of each of the discrete points includes: determining the thickness and length of the inner lip according to the aerodynamic requirements; determining a plurality of first control points for generating the first Bezier curve according to the position coordinates of the discrete points and the thickness and length of the inner lip; and generating the first Bezier curve according to the plurality of first control points.

[0009] Optionally, a second Bezier curve corresponding to the outer lip is determined according to the aerodynamic requirements, the inlet structure and the cabin structure, including: determining the thickness and length of the along-section curve of the outer lip according to the aerodynamic requirements and the cabin structure; determining a plurality of second control points for generating the second Bezier curve according to the position coordinates of the discrete points, the thickness and length of the outer lip; and generating the second Bezier curve according to the plurality of second control points.

[0010] Optionally, after determining the position coordinates of each of the discrete points, it also includes: calculating the slope of the cross-sectional curve of the inlet duct inlet at each of the discrete points; determining the relative position of the lip and the inlet duct inlet according to the profile line along the cross-sectional area to achieve the design of the lip, including: rotating the profile line along the cross-sectional area of ​​the lip according to the slope so that the profile line is perpendicular to the cross-sectional area of ​​the inlet duct inlet, and translating to the inlet duct inlet to achieve the design of the lip.

[0011] Optionally, calculating the slope of the cross-sectional curve of the inlet of the air intake duct at each of the discrete points includes: calculating the slope of the cross-sectional curve of the inlet of the air intake duct at each of the discrete points according to a first preset formula; the first preset formula is: ; Among them, X i-1 is the horizontal coordinate of the i-1th discrete point, Z i-1 is the ordinate of the i-1th discrete point, X i+1 is the horizontal coordinate of the i+1th discrete point, Z i+1 is the ordinate of the i+1th discrete point, n is the number of all discrete points, and i is an integer between 1 and n. is the slope corresponding to the i-th discrete point.

[0012] Optionally, the profile of the cross-section along the lip is rotated according to the slope so that the profile is perpendicular to the cross-section of the inlet duct, and is translated to the inlet duct to achieve the design of the lip, including: rotating the profile of the cross-section along the lip according to the slope and the rotation matrix so that the profile is perpendicular to the cross-section of the inlet duct; translating the rotated profile of the cross-section along the lip to the inlet duct according to the first translation matrix and the second translation matrix to achieve the design of the lip;

[0013] The rotation matrix is: ;

[0014] The first translation matrix is: ;

[0015] The second translation matrix is: ;

[0016] ;

[0017] in It is the coordinate data of the rotated profile; It is the coordinate data of the type line before rotation; is the first translation matrix, is the second translation matrix; Rotate is the rotation matrix; (LipCurve x0 , LipCurve z0 ) is the coordinate value of the first discrete point when the type line is sorted counterclockwise.

[0018] On the other hand, the present application provides a device for designing a lip of a drone, comprising: a memory for storing a computer program; and a processor for implementing the steps of the method for designing the lip of a drone as described above when executing the computer program.

[0019] On the other hand, the present application provides a non-volatile storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the method for designing a drone lip as described above are implemented.

[0020] On the other hand, the present application provides a drone, comprising a lip, wherein the structure of the lip is designed according to the drone lip design method as described above.

[0021] The present invention provides a design method, device, medium and drone for the lip of a drone. The method can determine the Bezier curves of the inner lip and the outer lip respectively on the basis of meeting the aerodynamic performance requirements by obtaining the structure of the drone air inlet entrance, the cabin structure and the aerodynamic requirements of the air inlet. Such curves can flexibly adjust the shape of the lip, thereby generating the profile of the lip along the cross section, and determine the relative position of the lip and the air inlet entrance according to these profiles. In this way, the geometric shape of the lip, especially the thickness and length of the lip, can be accurately controlled, so as to effectively deal with the aerodynamic separation problem caused by the air inlet being installed at the rear of the fuselage; especially the lip far away from the side of the fuselage, through the design of the Bezier curve, its incoming flow angle and aerodynamic characteristics can be optimized, and the aerodynamic separation phenomenon can be reduced, thereby improving the overall performance of the air inlet and the working efficiency of the entire propulsion system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A flow chart of a method for designing a lip of a drone provided by the present invention;

[0024] Figure 2 A discrete schematic diagram of an inlet cross-section curve provided by the present invention;

[0025] Figure 3 A schematic diagram of a transition law control curve provided by the present invention;

[0026] Figure 4 A schematic cross-sectional view of a lip of an air inlet provided by the present invention;

[0027] Figure 5 A schematic diagram of the lip deformation of an air inlet provided by the present invention;

[0028] Figure 6 The present invention provides a specific flow chart of a method for designing a lip of a drone. DETAILED DESCRIPTION

[0029] The core of the present invention is to provide a design method, device, medium and drone for the lip of a drone, which can accurately control the geometric shape of the lip, especially the thickness and length of the lip, so as to effectively deal with the aerodynamic separation problem caused by the installation of the air inlet on the rear part of the fuselage; especially the lip away from the side of the fuselage, through the design of Bezier curve, its incoming flow angle and aerodynamic characteristics can be optimized, the aerodynamic separation phenomenon can be reduced, and then the overall performance of the air inlet and the working efficiency of the entire propulsion system can be improved.

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] On the one hand, if Figure 1 As shown, the present application provides a method for designing a lip of a drone, including:

[0032] S11: Acquire the entrance structure of the air intake entrance of the UAV and the cabin structure of the UAV.

[0033] In the design method of the drone lip, this step involves obtaining the inlet structure and cabin structure of the drone. The principle of this process is to first accurately obtain the geometric shape of the inlet and the internal configuration of the cabin to understand its specific structural characteristics. This information usually includes the cross-sectional profile, geometric dimensions, shape of the inlet, and the spatial layout and constraints of the cabin. The structural data of the inlet helps identify the path and force of the airflow in and out of the inlet, while the cabin structural data provides information about space constraints and matching requirements. Through these structural data, it can be ensured that the subsequent design steps can be reasonably adjusted and optimized according to the actual physical conditions, so that the space constraints of the inlet and cabin can be effectively considered when designing the inner and outer lips, ensuring the accuracy and functionality of the lip design. This provides a basis for the Bezier curve design in the subsequent steps, so that the final lip design can match the actual structural conditions and optimize the aerodynamic performance.

[0034] S12: Obtain the aerodynamic requirements of the intake duct entrance.

[0035] In the design method of the UAV lip, this step involves obtaining the aerodynamic requirements of the inlet entrance. The principle of this step is to understand the aerodynamic performance standards that the inlet needs to meet during flight to ensure that the lip design can effectively support the efficiency and performance of the overall propulsion system. Aerodynamic requirements usually include parameters such as airflow velocity, flow rate, pressure distribution, and incoming flow angle at the inlet entrance. These requirements reflect the behavioral characteristics of the airflow in the inlet. For example, for medium and high-speed UAVs, aerodynamic requirements may include specific goals for the uniformity of the inlet airflow, reducing aerodynamic drag, and avoiding aerodynamic separation. By clarifying these aerodynamic performance standards, the geometric shape and size design of the lip can be guided to ensure that the inlet can optimize the airflow guidance, reduce aerodynamic losses, and improve the overall efficiency of the propulsion system under different flight conditions. Accurately obtaining aerodynamic requirements is a key step to ensure that the lip design meets the performance standards, which directly affects the determination of the Bezier curve in the subsequent design and the final functional realization of the lip.

[0036] S13: Determine a first Bezier curve corresponding to the inner lip and a second Bezier curve corresponding to the outer lip according to aerodynamic requirements, inlet structure and cabin structure, wherein the drone lip includes an inner lip and an outer lip.

[0037] In the design method of the lip of a UAV, this step involves determining the first Bezier curve corresponding to the inner lip and the second Bezier curve corresponding to the outer lip according to the aerodynamic requirements, the inlet structure and the cabin structure. The principle of this step is to achieve accurate lip design by converting these structural and aerodynamic requirements into operable geometric curves. First, according to the structure of the inlet and the space limitations of the cabin, the geometric shapes of the inner and outer lips need to be optimized under these constraints. Then, according to the preset aerodynamic requirements, such as optimizing the smoothness of the airflow and reducing fluid resistance, the geometric characteristics of the inner and outer lips are determined, including their thickness, length and their relative position to the inlet. Bezier curves can define and describe the curve shapes of these lips, and meet the requirements of aerodynamic performance by adjusting the control points. In this process, the first Bezier curve of the inner lip and the second Bezier curve of the outer lip respectively represent the geometric characteristics of the inner and outer sides of the lips. The design of these curves can effectively guide the airflow and ensure that the inlet can achieve optimized aerodynamic performance under various flight conditions. Therefore, under the premise of ensuring structural adaptation, the lip can be accurately designed and the aerodynamic characteristics can be optimized, thereby improving the working efficiency of the entire propulsion system.

[0038] S14: determining a profile of a cross section along the lip according to the first Bezier curve and the second Bezier curve, and determining a relative position of the lip and an inlet of the air inlet according to the profile of the cross section along the lip, so as to achieve design of the lip.

[0039] In the design method of the lip of the UAV, the principle of this step involves determining the profile of the section along the lip according to the first Bezier curve and the second Bezier curve, and determining the relative position of the lip and the inlet of the air inlet according to these profiles, so as to realize the design of the lip. Specifically, the Bezier curve defines the inner and outer contours of the lip through a set of control points, allowing the designer to accurately control the geometric shape of the lip. In this step, the profile of the section along the lip is first generated by the calculated first Bezier curve and the second Bezier curve, and these profiles describe the shape of the lip at different positions. Through these profiles, the overall profile and geometric characteristics of the lip at the inlet of the air inlet can be depicted. Subsequently, based on these profiles, the actual position of the lip at the inlet of the air inlet is further determined to ensure that it is accurately docked with the inlet of the air inlet. This process takes into account the aerodynamic requirements and structural limitations, optimizes the airflow guidance path, reduces aerodynamic losses, and improves the overall performance of the air inlet through precise geometric definition and position adjustment. Therefore, this step ensures the rationality and effectiveness of the lip design, so that it can meet the expected aerodynamic performance and structural requirements in practical applications.

[0040] In summary, the method for designing the drone lip provided by the present invention can determine the Bezier curves of the inner lip and the outer lip respectively on the basis of meeting the aerodynamic performance requirements by obtaining the structure of the drone air inlet entrance, the cabin structure and the aerodynamic requirements of the air inlet. This curve can flexibly adjust the shape of the lip, thereby generating the profile of the lip along the cross section, and determine the relative position of the lip and the air inlet entrance according to these profiles. In this way, the geometric shape of the lip, especially the thickness and length of the lip, can be accurately controlled, so as to effectively deal with the aerodynamic separation problem caused by the air inlet being installed at the rear of the fuselage; especially the lip far away from the side of the fuselage, through the design of the Bezier curve, its incoming flow angle and aerodynamic characteristics can be optimized, and the aerodynamic separation phenomenon can be reduced, thereby improving the overall performance of the air inlet and the working efficiency of the entire propulsion system.

[0041] Based on the above embodiments: Figure 2 As shown, in an optional embodiment, obtaining the inlet structure of the air inlet inlet of the UAV includes: obtaining the cross-sectional curve of the air inlet inlet of the UAV; after obtaining the inlet structure of the air inlet inlet of the UAV, further including: discretizing the cross-sectional curve to obtain multiple discrete points corresponding to the cross-sectional curve; determining the position coordinates of each discrete point; determining the first Bezier curve corresponding to the inner lip according to aerodynamic requirements, the inlet structure and the cabin structure, including: determining the first Bezier curve corresponding to the inner lip according to the aerodynamic requirements and the position coordinates of each discrete point.

[0042] In this embodiment, the process of obtaining the inlet structure of the drone air inlet inlet includes multiple steps, the first of which is to obtain the cross-sectional curve of the drone air inlet inlet. This cross-sectional curve provides geometric profile information of the air inlet inlet and is the basis for understanding its shape and size. Next, the cross-sectional curve is discretized and converted into multiple discrete points. The purpose of this discrete processing is to decompose the continuous cross-sectional curve into a series of discrete data points for subsequent calculations and analysis. The coordinates of each discrete point determine the geometric features of the cross-sectional curve at a specific position. These discrete points reflect the detailed geometry of the air inlet inlet, so that the design process can correspond to the actual structure more accurately. After determining the position coordinates of the discrete points, the first Bezier curve corresponding to the inner lip is further determined based on these data points as well as the aerodynamic requirements, the inlet structure and the cabin structure.

[0043] In this step, the curve shape of the inner lip can be optimized to meet the needs of airflow guidance and aerodynamic performance by combining the aerodynamic requirements and the coordinates of the discrete points. In this way, it can be ensured during the design process that the shape of the inner lip can effectively adapt to the structural characteristics and aerodynamic requirements of the inlet entrance, thereby achieving efficient intake performance and optimization of the overall propulsion system.

[0044] In an optional embodiment, a first Bezier curve corresponding to the inner lip is determined according to aerodynamic requirements and the position coordinates of each discrete point, including: determining the thickness and length of the inner lip according to the aerodynamic requirements; determining multiple first control points for generating the first Bezier curve according to the position coordinates of the discrete points, the thickness and length of the inner lip; and generating the first Bezier curve according to the multiple first control points.

[0045] In this embodiment, the process of determining the first Bezier curve corresponding to the inner lip according to the aerodynamic requirements and the position coordinates of each discrete point involves several steps. First, according to the aerodynamic requirements, the designer needs to determine the thickness and length of the inner lip. These parameters are to ensure that the inner lip can meet specific aerodynamic performance requirements, such as optimizing the guidance of airflow and reducing aerodynamic drag. After determining the thickness and length, the geometric shape of the inner lip needs to be further defined by the coordinates of the discrete points. The discrete points provide specific data of the cross-sectional curve of the inlet of the air inlet at a specific position, so that the designer can accurately capture the geometric characteristics of the inlet. Based on the position coordinates of these discrete points and the thickness and length of the inner lip, a plurality of first control points are generated. These control points are the key parameters of the Bezier curve, which define the shape and curvature of the curve. Through these control points, the designer can construct the first Bezier curve of the inner lip. The Bezier curve has high flexibility and can accurately describe the geometric shape of the inner lip and meet the requirements of aerodynamic performance. Finally, through the Bezier curve generated by these first control points, the designer can accurately describe the contour of the inner lip, thereby achieving precise control over its shape and ensuring that the aerodynamic performance of the inlet and the efficiency of the overall system are optimized.

[0046] In an optional embodiment, a second Bezier curve corresponding to the outer lip is determined according to aerodynamic requirements, an inlet structure, and a cabin structure, including: determining the thickness and length of the along-section curve of the outer lip according to the aerodynamic requirements and the cabin structure; determining a plurality of second control points for generating the second Bezier curve according to the position coordinates of discrete points, the thickness and length of the outer lip; and generating the second Bezier curve according to the plurality of second control points.

[0047] In this embodiment, the process of determining the second Bezier curve corresponding to the outer lip according to the aerodynamic requirements, the inlet structure and the cabin structure includes several steps. First, the thickness and length of the cross-sectional curve along the outer lip need to be determined according to the aerodynamic requirements and the cabin structure. These parameters determine the geometric shape and size of the outer lip, thereby affecting the guidance of the airflow and the overall aerodynamic performance. The determination of the thickness and length must meet the aerodynamic performance requirements, such as reducing resistance and improving airflow distribution, while also adapting to the space limitations of the cabin. Next, based on the position coordinates of the known discrete points, these discrete points reflect the cross-sectional shape of the inlet entrance, and the geometric characteristics of the outer lip can be derived through these discrete points. Combined with the thickness and length of the outer lip, multiple second control points for generating the second Bezier curve are determined. These control points define the specific shape of the outer lip, allowing the Bezier curve to flexibly describe its curve profile. Finally, the second Bezier curve is generated using these second control points, which accurately depicts the profile and geometric characteristics of the outer lip.

[0048] This approach allows the design of the outer lip to be optimized while meeting aerodynamic performance and cabin structure requirements, thereby improving the overall efficiency of the inlet and the performance of the propulsion system.

[0049] In an optional embodiment, after determining the position coordinates of each discrete point, it also includes: calculating the slope of the cross-sectional curve of the inlet duct inlet at each discrete point; determining the relative position of the lip and the inlet duct inlet according to the profile line along the cross-sectional area to achieve the design of the lip, including: rotating the profile line of the cross-sectional area of ​​the lip according to the slope so that the profile line is perpendicular to the cross-sectional area of ​​the inlet duct inlet, and translating to the inlet duct inlet to achieve the design of the lip.

[0050] In this optional embodiment, after determining the position coordinates of each discrete point, it is first necessary to calculate the slope of the cross-sectional curve of the inlet of the air inlet at each discrete point. The principle of this step is that the slope provides the tangent direction of the cross-sectional curve at each discrete point, that is, the local slope information of the curve. These slope data are crucial for the subsequent lip design because they determine how the profile of the cross-sectional profile of the lip along the way is docked with the geometric shape of the inlet of the air inlet. The process of calculating the slope is usually implemented by a difference method or a fitting method to ensure that the slope value can accurately reflect the actual change of the cross-sectional curve. Next, according to the calculated slope, the cross-sectional profile of the lip along the way is rotated so that it is perpendicular to the cross-sectional profile of the inlet of the air inlet. This rotation ensures that the design of the lip matches the inlet geometry of the air inlet, thereby optimizing the guidance of the airflow and reducing the aerodynamic drag. After the rotation is completed, the profile needs to be translated to the inlet of the air inlet to ensure that the position of the lip is docked with the actual position of the inlet of the air inlet. This process enables the designed lip to be effectively combined with the inlet of the air inlet in actual installation to ensure smooth entry of the airflow. Through these steps, a precise lip design can be achieved that meets aerodynamic performance requirements and optimizes the efficiency of the overall propulsion system.

[0051] In an optional embodiment, calculating the slope of the cross-sectional curve of the inlet of the air intake duct at each discrete point includes: calculating the slope of the cross-sectional curve of the inlet of the air intake duct at each discrete point according to a first preset formula;

[0052] The first preset formula is: ; Among them, X i-1 is the horizontal coordinate of the i-1th discrete point, Z i-1 is the ordinate of the i-1th discrete point, X i+1 is the horizontal coordinate of the i+1th discrete point, Z i+1 is the ordinate of the i+1th discrete point, n is the number of all discrete points, and i is an integer between 1 and n. is the slope corresponding to the i-th discrete point.

[0053] In an optional embodiment, the profile of the cross section of the lip is rotated according to the slope so that the profile is perpendicular to the cross section of the inlet duct, and is translated to the inlet duct to achieve the design of the lip, including: rotating the profile of the cross section of the lip according to the slope and the rotation matrix so that the profile is perpendicular to the cross section of the inlet duct; translating the rotated profile of the cross section to the inlet duct according to the first translation matrix and the second translation matrix to achieve the design of the lip;

[0054] The rotation matrix is: ;

[0055] The first translation matrix is: ;

[0056] The second translation matrix is: ;

[0057] ;

[0058] Among them, LipCurve1 is the coordinate data of the line after rotation; LipCurve is the coordinate data of the line before rotation; Tran1 is the first translation matrix, Tran2 is the second translation matrix; Rotate is the rotation matrix; (LipCurve x0 , LipCurve z0 ) is the coordinate value of the first discrete point when the type line is sorted counterclockwise.

[0059] In a specific embodiment, Figure 6 As shown, the steps of the design method of the drone lip are as follows:

[0060] (1) Extract the inlet duct inlet cross-section curve, discretize it into a point set consisting of n points (1, 2, 3, ..., i-1, i, i+1, ..., n), and sort them counterclockwise according to their inlet duct inlet position coordinates, and calculate the slope of the curve at each discrete point. The calculation formula is the same as the first preset formula above.

[0061] (2) Determine the height H of the inner lip according to the aerodynamic requirements of the drone in , and its length L in .

[0062] (3) Based on the position coordinates of the inlet entrance section, the inner lip contraction ratio and the inner lip length, the first control point of the first Bezier curve for generating the inner lip is arranged, and the curve adjustment variable M is introduced. in 、N in ; Use the discrete points on the inlet section curve as the first control point of the first Bezier curve for each inner lip along the way , arrange the second control point ; Arrange the third control point , arrange the fourth control point ;in The value range is (0, 1). The value range is (0, 1), and the transition rule can be expressed as: , where z is the ordinate of the transition line between two adjacent control points, and x is the abscissa of the transition line between two adjacent control points. The transition curve is as follows: Figure 3 As shown, C is the control parameter of the Bezier curve ( Figure 3 The values ​​of C are -3, 0, and 3 respectively, which can optimize the inner lip profile while determining the inner lip length and thickness to better meet the lip design requirements.

[0063] (4) Generate the first Bezier curve according to the control points generated above. This design method uses a cubic Bezier curve with four first control points to design the lip. The first Bezier curve is generated by a linear combination of the Bernstein basis function and the four first control points: The formula of the nth-order first Bezier curve with (n+1) control points is as follows:

[0064] ;

[0065] Among them, Pi is the i-th first control point, The Bernstein basis function can be expressed as:

[0066] ;

[0067] Then the cubic Bezier curve can be expressed as:

[0068] ;

[0069] This method generates the inner lip profile .

[0070] (5) According to the structure and aerodynamic requirements of the UAV, determine the thickness H of each outer lip section along the way. out And length L out .

[0071] (6) Determine the second control point of the second Bezier curve for generating the outer lip, and arrange the control point P0 of the first outer lip out =P3 in ; Arrange the control points of the second outer lip ; Arrange the third control point ; Arrange the fourth control point , , is the ordinate of the i-th discrete point on the inlet cross section, where The value range is (0, 1). The value range is (0, 1); and is the control parameter of the second Bezier curve, which can optimize the inner lip profile while determining the length and thickness of the outer lip.

[0072] (7) Generate the outer lip profile using the same steps as in step (4).

[0073] (8) The inner lip and outer lip profiles are spliced ​​together. Since the inner and outer lips generated by the above lip curve generation method are in 0 intersects, and is twice continuous at the intersection, so the inner and outer lips can be directly spliced, that is: ; The cross section generated after splicing is as follows Figure 4 shown.

[0074] (9) Rotate the profiles of each lip to make them perpendicular to the cross-sectional curve of the inlet. This process is completed by the rotation matrix and translation matrix mentioned above to complete the design of the lip. The result is as follows: Figure 5 shown.

[0075] In summary, the design method provided in this application can not only meet the basic aerodynamic requirements of the lip, but also be better connected with the cabin and the air inlet of the subsonic UAV to make a smooth transition; and by modifying the relevant parameters, the shape and size of each cross-section of the lip can be controlled; and the design requirements of the variable thickness lip of medium and high speed subsonic UAVs can be met.

[0076] On the other hand, the present application provides a design device for a drone lip, comprising: a memory for storing a computer program; a processor for implementing the steps of the above-mentioned drone lip design method when executing the computer program. For an introduction to the drone lip design device, please refer to the above-mentioned embodiment, and the present application will not repeat it here.

[0077] On the other hand, the present application provides a non-volatile storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned method for designing the lip of a drone are implemented. For the introduction of the non-volatile storage medium, please refer to the above-mentioned embodiment, and the present application will not repeat it here.

[0078] On the other hand, the present application provides a drone, including a lip, wherein the structure of the lip is designed according to the above-mentioned drone lip design method. For the introduction of the drone, please refer to the above-mentioned embodiment, and the present application will not repeat it here.

[0079] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0080] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for designing a lip of a drone, characterized in that: include: Acquire an inlet structure of an air inlet of a UAV and a cabin structure of the UAV; Obtaining aerodynamic requirements of the air inlet; Determine a first Bezier curve corresponding to an inner lip and a second Bezier curve corresponding to an outer lip according to the aerodynamic requirements, the inlet structure and the cabin structure, wherein the drone lip includes the inner lip and the outer lip; Determine a profile of a cross section along the lip according to the first Bezier curve and the second Bezier curve, and determine a relative position of the lip and the inlet of the air inlet according to the profile of the cross section along the lip, so as to achieve design of the lip; The inlet structure of the air inlet includes the geometric shape of the air inlet and the internal configuration of the cabin, the geometric shape includes the cross-sectional profile, geometric dimensions and shape of the air inlet of the air inlet, the internal configuration of the cabin includes the spatial layout and restriction conditions of the cabin; the aerodynamic requirements include parameters reflecting the behavior characteristics of the airflow in the air inlet; Determining a first Bezier curve corresponding to the inner lip and a second Bezier curve corresponding to the outer lip according to the aerodynamic requirements, the inlet structure and the cabin structure, including: Determine the thickness and length of the inner lip according to the aerodynamic requirements and the inlet structure, and determine a first Bezier curve corresponding to the inner lip according to the thickness and length of the inner lip; Determine the thickness and length of the cross-sectional curve along the outer lip according to the aerodynamic requirements and the cabin structure, and determine the second Bezier curve corresponding to the outer lip according to the thickness and length of the cross-sectional curve along the outer lip; The relative position of the lip and the inlet of the air inlet is determined according to the profile of the longitudinal section to achieve the design of the lip, including: The profile line of the longitudinal section of the lip is rotated so that the profile line is perpendicular to the section of the inlet of the air inlet and is translated to the inlet of the air inlet to realize the design of the lip.

2. The method for designing the lip of a drone as claimed in claim 1, characterized in that: Obtaining the inlet structure of the air inlet of the UAV, including: Obtaining a cross-sectional curve of an air inlet entrance of the UAV; After obtaining the inlet structure of the air inlet of the UAV, the method further includes: Performing discretization on the cross-sectional curve to obtain a plurality of discrete points corresponding to the cross-sectional curve; Determine the position coordinates of each of the discrete points; Determining a first Bezier curve corresponding to the inner lip according to the aerodynamic requirements, the inlet structure, and the cabin structure includes: According to the aerodynamic requirements and the position coordinates of each of the discrete points, a first Bezier curve corresponding to the inner lip is determined.

3. The method for designing the lip of a drone as claimed in claim 2, characterized in that: Determining a first Bezier curve corresponding to the inner lip according to the aerodynamic requirements and the position coordinates of each discrete point includes: Determining a plurality of first control points for generating the first Bezier curve according to the position coordinates of the discrete points, the thickness and the length of the inner lip; The first Bezier curve is generated according to the first control points.

4. The method for designing the lip of a drone as claimed in claim 2, characterized in that: Determining a second Bezier curve corresponding to the outer lip according to the aerodynamic requirements, the inlet structure, and the cabin structure includes: Determining a plurality of second control points for generating the second Bezier curve according to the position coordinates of the discrete points, the thickness and the length of the outer lip; The second Bezier curve is generated according to the plurality of second control points.

5. The method for designing the lip of a drone according to any one of claims 2 to 4, characterized in that: After determining the position coordinates of each discrete point, the method further includes: Calculating the slope of the cross-sectional curve of the inlet of the air intake duct at each of the discrete points; The relative position of the lip and the inlet of the air inlet is determined according to the profile of the longitudinal section to achieve the design of the lip, including: The profile of the cross section of the lip is rotated according to the slope so that the profile is perpendicular to the cross section of the inlet and is translated to the inlet to achieve the design of the lip.

6. The method for designing the lip of a drone as claimed in claim 5, characterized in that: Calculating the slope of the cross-sectional curve of the inlet port at each discrete point includes: Calculating the slope of the cross-sectional curve of the inlet of the air intake duct at each discrete point according to a first preset formula; The first preset formula is: ； Among them, X i-1 is the horizontal coordinate of the i-1th discrete point, Z i-1 is the ordinate of the i-1th discrete point, X i+1 is the horizontal coordinate of the i+1th discrete point, Z i+1 is the ordinate of the i+1th discrete point, n is the number of all discrete points, and i is an integer between 1 and n. is the slope corresponding to the i-th discrete point.

7. The method for designing the lip of a drone as claimed in claim 6, characterized in that: The profile of the cross section of the lip is rotated according to the slope so that the profile is perpendicular to the cross section of the inlet and translated to the inlet to achieve the design of the lip, including: Rotating the profile of the cross section of the lip according to the slope and the rotation matrix so that the profile is perpendicular to the cross section of the inlet; According to the first translation matrix and the second translation matrix, the profile of the rotated longitudinal section is translated to the inlet of the air inlet to realize the design of the lip; The rotation matrix is: ； The first translation matrix is: ; The second translation matrix is: ; ； in It is the coordinate data of the rotated profile; It is the coordinate data of the type line before rotation; is the first translation matrix, is the second translation matrix; Rotate is the rotation matrix; ( LipCurve x0 , LipCurve z0 ) is the coordinate value of the first discrete point when the type line is sorted counterclockwise.

8. A design device for the lip of a drone, characterized in that: include: Memory for storing computer programs; A processor is used to implement the steps of the method for designing the lip of a drone as described in any one of claims 1 to 7 when executing a computer program.

9. A non-volatile storage medium, characterized in that: The non-volatile storage medium stores a computer program, and when the computer program is executed by the processor, the steps of the method for designing the lip of a drone as described in any one of claims 1 to 7 are implemented.

10. A drone, characterized in that: It comprises a lip, the structure of which is designed according to the design method for the lip of a drone as described in any one of claims 1-7.

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