Optimization method for cabin door retracting and releasing mechanism of unmanned aerial vehicle

Abstract

The invention discloses an optimization method of an unmanned aerial vehicle cabin door retracting and releasing mechanism, which comprises the following steps: S1, carrying out simplified assumption on the unmanned aerial vehicle cabin door retracting and releasing mechanism, and confirming the type of the cabin door retracting and releasing mechanism; s2, determining the type of a connection pair of the cabin door retracting and releasing mechanism of the unmanned aerial vehicle, and obtaining point coordinates required for constructing the cabin door retracting and releasing mechanism; s3, constructing a cabin door folding and unfolding mechanism parameterized model according to the cabin door folding and unfolding mechanism simplified hypothesis and the point coordinates; s4, the gravity load is applied to the gravity centers of all the components; cabin door aerodynamic resistance loads are applied to the center of the cabin door curved surface, and all the loads take effect; s5, according to the minimum length of each component of the cabin door retracting and releasing mechanism, cabin door retracting and releasing angle limitation and cabin door retracting and releasing mechanism point coordinate space limitation, constructing a related constraint function; s6, confirming a target function according to the load requirement of a connecting part which is easy to deform or fail in the cabin door folding and unfolding structure; and S7, optimizing the target function, and determining the overall arrangement of the cabin door retracting and releasing mechanism.

Description

Technical Field

[0001] The invention relates to the field of aviation technology, and in particular to an optimization method for a retractable and deployable mechanism of a cabin door of an unmanned aerial vehicle. Background Art

[0002] As drones are light, fuel-efficient, and easy to maintain, the demand for drones is increasing as they are used in various fields at home and abroad. Various drones have customized space layouts, which means that the door retraction mechanism of drones also needs to be personalized according to their space layout.

[0003] The hatch door retraction mechanism of a drone is usually installed in the limited cabin of the drone, where there are other parts such as landing gear and retraction cylinder, so the spatial layout is greatly restricted. The spatial layout of the hatch door retraction mechanism not only needs to consider that there is no interference with other parts such as landing gear and retraction cylinder in the cabin during the retraction process, but also needs to consider that the retraction load meets the design requirements during the entire retraction process, and the preload requirements when the hatch door is retracted need to be met to a certain extent, which is a difficult problem for the design layout of the hatch door retraction mechanism.

[0004] Conventional door retraction and extension mechanism spatial layout mostly uses three-dimensional digital models to establish associated motion to give priority to non-interference requirements, and then repeatedly adjusts to make the retraction and extension process, retraction and extension load, etc. reach an acceptable range; such a design method is time-consuming and labor-intensive, and it is impossible to consider all constraints in a unified manner. Sometimes after the design is completed, one of the key constraints or design requirements cannot be met. At this time, the design needs to be iterated repeatedly. When one or more design requirements change, the design iteration of the spatial layout needs to confirm whether the design requirements are met by adjusting the digital model, which is not conducive to the rapid update of the spatial layout. Summary of the invention

[0005] In view of the technical problem that the spatial layout design of the unmanned aerial vehicle cabin door retracting and extending mechanism in the prior art is time-consuming, the present invention proposes an optimization method for the unmanned aerial vehicle cabin door retracting and extending mechanism.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for optimizing a door retracting and extending mechanism of a drone cabin comprises the following steps:

[0008] S1: Make simplified assumptions about the door retraction mechanism of the UAV and confirm the type of the door retraction mechanism;

[0009] S2: Confirm the connection sub-category of the UAV door retracting and releasing mechanism, and obtain the point coordinates required for the construction of the door retracting and releasing mechanism;

[0010] S3: Based on the simplified assumptions and point coordinates of the hatch door retracting and extending mechanism, a parameterized model of the hatch door retracting and extending mechanism is constructed;

[0011] S4: Apply gravity load to the center of gravity of all components; apply door aerodynamic drag load to the center of door surface, and set each load to take effect;

[0012] S5: Construct relevant constraint functions according to the minimum length of each component of the door retracting and extending mechanism, the door retracting and extending angle limit, and the point coordinate space limit of the door retracting and extending mechanism;

[0013] S6: Confirm the objective function according to the load requirements of the connection points that are prone to deformation or failure in the door retractable structure;

[0014] S7: Use existing analysis software to optimize the objective function and determine the overall layout of the hatch door retracting and extending mechanism.

[0015] Preferably, in S1, the following simplified assumptions are made for the unmanned aerial vehicle cabin door retracting and extending mechanism, including:

[0016] Assumption 1: The shapes of all components in the UAV door retracting and extending mechanism are replaced by point-line models, ignoring fit and clearance;

[0017] Assumption 2: The coordinates of the connection points of all components in the UAV door retracting and releasing mechanism are the center points of the connection areas;

[0018] Assumption 3: The load applied to the UAV door retraction mechanism is a concentrated force;

[0019] Assumption 4: The retracted and extended state of the landing gear associated with the retractable and extended mechanism of the UAV cabin door has been determined;

[0020] Assumption 5: The aerodynamic drag of the door has been determined.

[0021] Preferably, in S1, types of the door retracting and extending mechanism include a landing gear follower type and an autonomous motion type.

[0022] Preferably, S2 includes:

[0023] S2-1: Establish the Cartesian coordinate system of the UAV door retracting and releasing mechanism: the positive direction of the X axis is from the tail to the nose of the UAV, the positive direction of the Y axis is perpendicular to the X axis and located in the same horizontal plane; the positive direction of the Z axis is the sky direction;

[0024] S2-2: After assembling the hatch door retracting and extending mechanism to the Cartesian coordinate system, the category of the connection pair of the hatch door retracting and extending mechanism is identified, and the required number of points is confirmed based on the category and point overlap.

[0025] Preferably, in S2-2, the number of points required is: 1 point required for the ball joint, 2 points required for the rotation joint, 2 points required for the translation joint, 1 point required for applying a single load, 1 point required for the center of mass of a single component, 2 points for constructing a single cylindrical component, 2 points for constructing a single tie rod component, 3 points for constructing a single triangular prism component, and 2 points for constructing a single rectangular component.

[0026] Preferably, S3 includes:

[0027] S3-1: Form a point coordinate matrix X based on the point coordinates:

[0028]

[0029] In formula (1), x1 represents the x-axis coordinate of the first point; y1 represents the y-axis coordinate of the first point; z1 represents the z-axis coordinate of the first point; n Indicates the x-axis coordinate of the nth point; y n Indicates the y-axis coordinate of the nth point; z n Indicates the z-axis coordinate of the nth point;

[0030] S3-2: parameterize the original point coordinate matrix and determine the design variables DVi, i = 1, 2, ..., 15;

[0031] S3-3: Establish a parametric model based on design variables: Use the design variables of the points to draw regular shapes, and use the points of the connection pairs to establish connection pairs between the various components, so as to perform parametric modeling of the hatch door retraction and extension mechanism.

[0032] Preferably, the S3-2 includes:

[0033] S3-2-1: Identify the related points, and then perform parameterization to determine the design variables DVi, i = 1, 2, ..., 15;

[0034] S3-2-2: Set the valid value range for the design variables:

[0035] DVi+30≥DVi≥DVi-30, i=1,2,...,15 (2)

[0036] In formula (2), DVi represents the i-th design variable.

[0037] Preferably, the S5 includes:

[0038] S5-1: Construct the length constraint function of each component in the hatch retracting and extending mechanism:

[0039]

[0040] In formula (3), g1(X) represents the length constraint function of each component of the door retracting and releasing mechanism; n represents the number of components, L i (X) represents the length of the i-th component; L i,min represents the minimum length of the i-th component;

[0041] S5-2: Construct the angle limit constraint function of the hatch door retracting and extending mechanism:

[0042] g2(X)=θ(X)-θ max ≤0 (4)

[0043] In formula (4), g29X) represents the angle limit constraint function of the door retracting and releasing mechanism; θ(X) represents the door rotation angle; θ max Indicates the maximum rotation angle of the door;

[0044] S5-3: Construct the space restriction constraint function of the hatch door retracting and extending mechanism:

[0045]

[0046] In formula (5), g3(X) represents the space restriction constraint function of the door retracting and releasing mechanism point; m represents the number of contact forces; CONTACT(X) i represents the i-th contact force.

[0047] Preferably, in S5-2, the maximum rotation angle θ of the door max Not greater than 100°, i.e. θ max -100≤0.

[0048] Preferably, in S6, the objective function is:

[0049]

[0050] In formula (6), F 1,x (X), F 1,y (X), F 1,z (X) respectively represent the x-axial force component, y-axial force component and z-axial force component of the connection joint between the landing gear and the door retraction mechanism.

[0051] In summary, due to the adoption of the above technical solution, compared with the prior art, the present invention has at least the following beneficial effects:

[0052] The present invention saves time and calculation cost for the initial layout design of the door retracting and extending mechanism, provides a guarantee for the rapid iteration of the layout of the door retracting and extending mechanism, and simplifies the load analysis and motion state analysis of the door retracting and extending mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1Schematic diagram of an optimization method for a drone door retracting and extending mechanism according to an exemplary embodiment of the present invention.

[0054] Figure 2 It is a schematic diagram of a parameterized model of a hatch door retracting and extending mechanism according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0055] The present invention is further described in detail below in conjunction with the examples and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0056] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0057] like Figure 1 As shown, the present invention provides an optimization method for a drone cabin door retracting and extending mechanism, which specifically includes the following steps:

[0058] S1: Make simplified assumptions about the UAV door retraction and extension mechanism, and confirm the type of door retraction and extension mechanism, including landing gear follow-up type and autonomous motion type.

[0059] In this embodiment, the following simplified assumptions are made for the drone door retracting and extending mechanism, including:

[0060] Assumption 1: The shapes of all components in the UAV door retracting and extending mechanism are replaced by point-line models, ignoring irrelevant parameters such as fit and clearance;

[0061] Assumption 2: The coordinates of the connection points of all components in the UAV door retracting and releasing mechanism are the center points of the connection areas;

[0062] Assumption 3: The load applied to the UAV door retraction mechanism is a concentrated force;

[0063] Assumption 4: The retracted and extended state of the landing gear associated with the retractable and extended mechanism of the UAV cabin door has been determined;

[0064] Assumption 5: The aerodynamic drag of the door has been determined.

[0065] In this embodiment, different optimization strategies are determined according to the type of the door retracting and extending mechanism. The autonomous motion type means that the door retracting and extending mechanism is not connected to the landing gear, and the landing gear retraction and extension and the door retracting and extending mechanism are respectively completed by two sets of independent driving mechanisms; the landing gear follower type means that the door retracting and extending mechanism is connected to the landing gear and must move in coordination with the retraction or extension of the landing gear, and the door retracting and extending state is restricted by the state of the landing gear.

[0066] Therefore, the landing gear follower type only needs to set one drive function to realize the retraction and extension of the landing gear and the door at the same time. Since the autonomous motion type door retraction and extension mechanism does not move simultaneously with the retraction and extension of the landing gear, generally, the landing gear is in a fully retracted state during the entire process from the door being fully retracted to being fully extended, and the landing gear is not lowered until the door is fully lowered; therefore, the autonomous motion type needs to set two drive functions to realize the retraction and extension of the landing gear and the door respectively, and the landing gear can only be lowered after the door is fully lowered.

[0067] S2: Confirm the connection sub-category of the UAV door retracting and extending mechanism, obtain the point coordinates required for the construction of the door retracting and extending mechanism, the relevant performance limitations of the door retracting and extending mechanism, and the operating conditions (including load and working status).

[0068] In this embodiment, a Cartesian coordinate system of the drone door retracting and releasing mechanism is established: from the tail to the nose of the drone is the positive direction of the X axis, and the direction perpendicular to the X axis and located in the same horizontal plane is the positive direction of the Y axis; the sky direction is the positive direction of the Z axis;

[0069] In this embodiment, after the hatch door retracting and extending mechanism is assembled to the correct Cartesian coordinate system, the category of the connecting pair of the hatch door retracting and extending mechanism is identified, and the number of points required is confirmed by the category and the point overlap (reusable points, thereby reducing the point setting): 1 point is required for the ball pair, 2 points are required for the rotation pair, and 2 points are required for the translation pair; in addition to the points required for the connecting pair, other points include 1 point required for single load application, 1 point required for the center of mass of a single component, 2 points for constructing a single cylindrical component, 2 points for constructing a single tie rod component, 3 points for constructing a single triangular prism component, 2 points for constructing a single rectangular component, etc.

[0070] S3: Based on the simplified assumptions and point coordinates of the hatch door retracting and extending mechanism, a parametric model of the hatch door retracting and extending mechanism is constructed.

[0071] In this embodiment, a parameterized model of the door retracting and extending mechanism is constructed based on the simplified assumption of the door retracting and extending mechanism in S1 and the point coordinates of the door retracting and extending mechanism in S2 (which can be determined by assumption 2), and can be updated autonomously according to the adjustment of the point coordinates.

[0072] S3-1: In this embodiment, the variable parameters in the point coordinates are set as design variables to form a point coordinate matrix X, as shown in Table 1.

[0073]

[0074] In formula (1), x1 represents the x-axis coordinate of the first point; y1 represents the y-axis coordinate of the first point; z1 represents the z-axis coordinate of the first point; n Indicates the x-axis coordinate of the nth point; y n Indicates the y-axis coordinate of the nth point; z n Indicates the z-axis coordinate of the nth point.

[0075] Table 1. Point coordinates

[0076]

[0077]

[0078] S3-2: Parameterize the original point coordinate matrix and determine the design variables.

[0079] S3-2-1: Identify the related points, then parameterize and determine the design variables.

[0080] In this embodiment, the associated points include points with symmetrical relationships, coplanar relationships, colinear relationships, etc. These points need to be identified in advance before parameterization in order to simplify the number of parameterized variables.

[0081] In this embodiment, the point coordinates in Table 1 are parameterized to obtain design variables DVi, i=1, 2, ..., 15, as shown in Table 2.

[0082] Table 2. Design variables determination

[0083]

[0084]

[0085] S3-2-2: Set the valid value range for the design variables.

[0086] According to the landing gear system structure and rapid update iteration, the valid value range of the design variables is set as follows: the point coordinates must satisfy the requirement that a certain avoidance space can be maintained in the cabin space during the entire movement of the landing gear system. The set points are used to draw regular shapes such as rectangles, triangular prisms, cylinders, etc. to simplify the modeling of the landing gear system.

[0087] In this embodiment, comprehensive table 2 can set the range of design variables.

[0088] DVi+30≥DVi≥DVi-30, i=1,2,...,15 (2)

[0089] In formula (2), DVi represents the i-th design variable.

[0090] S3-3: Establish a parametric model based on design variables.

[0091] Use the set design variables to draw regular shapes such as cuboids, triangular prisms, cylinders, etc. to perform parametric modeling of the landing gear system. For example, the tie rod can be replaced by a cylinder, and the connection points are used to establish connection pairs between the various components. Figure 2 As shown, 1 is a landing gear, 2, 3, 4, 5 are the first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod of the door mechanism, and 6 is a door.

[0092] S4: Apply gravity load to the center of gravity of all components (landing gear, first link, second link, third link, fourth link, door, etc.); apply door aerodynamic drag load to the center of the door surface, and set the effectiveness of each load.

[0093] Among them, the gravity load is always effective, and the aerodynamic drag load of the hatch includes the celestial load F y , heading load F x and the lateral load F z , are set as functions related to the angle θ(X) of the door rotation.

[0094] S5: Construct relevant constraint functions according to the minimum length of each component of the door retracting and extending mechanism, the door retracting and extending angle limit, and the point coordinate space limit of the door retracting and extending mechanism.

[0095] In this embodiment, the minimum length of each component of the door retracting mechanism, the angle limit of the door retracting structure, and the spatial limit of the point coordinates of the door retracting mechanism are converted into constraint functions g1(X), g2(X), and g3(X) to limit the effective values ​​of the design variables, wherein the minimum length limit of each component of the door retracting mechanism depends on the design requirements of the door retracting mechanism, the angle limit of the door retracting structure depends on the landing gear layout requirements, and the point coordinate space limit depends on the space limit of the cabin layout of the UAV door retracting mechanism.

[0096] S5-1: Construct the length constraint function of each component in the hatch door retracting and extending mechanism: Each component is affected by the structural characteristics and has a minimum length restriction, namely:

[0097]

[0098] In formula (3), g1(X) represents the length constraint function of each component of the door retracting and releasing mechanism; n represents the number of components, L i (X) represents the length of the i-th component; L i,min Indicates the minimum length of the i-th component.

[0099] For example, the minimum length limit of each connecting rod:

[0100] The distance between point 3 and point 4 is greater than 20 mm:

[0101] 20-DISTANCE(POINT3,POINT4)≤0;

[0102] The distance between point 4 and point 5 is greater than 13 mm:

[0103] 13-DISTANCE(POINT4,POINT5)≤0;

[0104] The distance between point 3 and point 4 is greater than 20 mm:

[0105] 20-DISTANCE(POINT3,POINT4)≤0;

[0106] The distance between point 4 and point 6 is greater than 90 mm:

[0107] 90-DISTANCE(POINT4,POINT6)≤0;

[0108] The distance between point 6 and point 7 is greater than 13 mm:

[0109] 13-DISTANCE(POINT6,POINT7)≤0;

[0110] The distance between point 7 and point 8 is greater than 20 mm:

[0111] 20-DISTANCE(POINT7,POINT8)≤0.

[0112] S5-2: Construct the angle limit constraint function of the door retracting mechanism: When the door is lowered to the maximum angle, it needs to maintain a certain avoidance distance from the fuselage skin. For the convenience of calculation, the avoidance distance limit is converted into the limit of the maximum rotation angle of the door, that is:

[0113] g2(X)=θ(X)-θ max ≤0 (4)

[0114] In formula (4), g2(X) represents the angle limit constraint function of the door retracting and releasing mechanism; θ(X) represents the door rotation angle; θ max Indicates the maximum rotation angle of the door.

[0115] In this embodiment, the maximum rotation angle of the door shall not be greater than 100°:

[0116] θ max -100≤0.

[0117] S5-3: Construct the point space restriction constraint function of the door retracting mechanism: The layout of the door retracting mechanism is restricted by the point space, and it must not interfere with the point space and maintain a certain avoidance distance during the entire retracting process. For this reason, the point space constraint is transformed: the point space is reduced so that the reduced point space and the original point space always maintain the avoidance distance requirement, and the reduced point space is contacted with the various components of the door retracting mechanism; in addition, since there are many moving parts in the door retracting mechanism, contact constraints need to be established between the moving parts and between the moving parts and the landing gear; the final constraint function is:

[0118]

[0119] In formula (5), g3(X) represents the space restriction constraint function of the door retracting and releasing mechanism point; m represents the number of contact forces; CONTACT(X) i represents the i-th contact force.

[0120] S6: Determine the relevant objective function according to the loads on the connections that are prone to deformation or failure in the door retractable structure.

[0121] In this embodiment, the connection with the largest load is the connection between the landing gear and the door retracting mechanism, so the connection load F1 between the landing gear and the door retracting mechanism is taken as the objective function, that is:

[0122]

[0123] In formula (6), Q represents the objective function; F 1,x (X), F 1,y (X), F 1,z (X) represent the x-axial force component, y-axial force component and z-axial force component of the connection between the landing gear and the door retraction mechanism.

[0124] S7: Use existing analysis software (ADAMS / ANSYS MOTION / LMS VIRTUAL LAB / NASTRAN / ABAQUS) to optimize the objective function, that is, optimize the points required to construct the hatch door retracting and extending mechanism, and finally optimize the overall layout of the hatch door retracting and extending mechanism.

[0125] In this embodiment, the constructed parameterized model is also simulated, and the results are shown in Table 3:

[0126] Table 3. Point matrix update table

[0127]

[0128]

[0129] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A method for optimizing the retractable mechanism of a UAV cabin door, characterized in that: The specific steps include: S1: Make simplified assumptions about the door retraction mechanism of the UAV and confirm the type of the door retraction mechanism; S2: Confirm the connection sub-category of the UAV door retracting and releasing mechanism, and obtain the point coordinates required for the construction of the door retracting and releasing mechanism; S3: Based on the simplified assumptions and point coordinates of the hatch door retracting and extending mechanism, a parameterized model of the hatch door retracting and extending mechanism is constructed; S4: Apply gravity load to the center of gravity of all components; apply door aerodynamic drag load to the center of door surface, and set each load to take effect; S5: Construct relevant constraint functions according to the minimum length of each component of the door retracting and extending mechanism, the door retracting and extending angle limit, and the point coordinate space limit of the door retracting and extending mechanism; S6: Confirm the objective function according to the load requirements of the connection points that are prone to deformation or failure in the door retractable structure; S7: Use existing analysis software to optimize the objective function and determine the overall layout of the hatch door retracting and extending mechanism.

2. The optimization method of the unmanned aerial vehicle door retracting and extending mechanism according to claim 1, characterized in that: In S1, the following simplified assumptions are made for the UAV door retraction and extension mechanism, including: Assumption 1: The shapes of all components in the UAV door retracting and extending mechanism are replaced by point-line models, ignoring fit and clearance; Assumption 2: The coordinates of the connection points of all components in the UAV door retracting and releasing mechanism are the center points of the connection areas; Assumption 3: The load applied to the UAV door retraction mechanism is a concentrated force; Assumption 4: The retracted and extended state of the landing gear associated with the retractable and extended mechanism of the UAV cabin door has been determined; Assumption 5: The aerodynamic drag of the door has been determined.

3. The optimization method of the unmanned aerial vehicle cabin door retracting and extending mechanism according to claim 1, characterized in that: In S1, the types of the door retracting and extending mechanisms include a landing gear follower type and an autonomous motion type.

4. The optimization method of the unmanned aerial vehicle door retracting and extending mechanism according to claim 1, characterized in that: The S2 includes: S2-1: Establish the Cartesian coordinate system of the UAV door retracting and releasing mechanism: the positive direction of the X axis is from the tail to the nose of the UAV, the positive direction of the Y axis is perpendicular to the X axis and located in the same horizontal plane; the positive direction of the Z axis is the sky direction; S2-2: After assembling the hatch door retracting and extending mechanism to the Cartesian coordinate system, the category of the connection pair of the hatch door retracting and extending mechanism is identified, and the required number of points is confirmed based on the category and point overlap.

5. The optimization method of the unmanned aerial vehicle cabin door retracting and extending mechanism according to claim 4, characterized in that: In S2-2, the number of points required is: 1 point required for the ball joint, 2 points required for the rotation joint, 2 points required for the translation joint, 1 point required for applying a single load, 1 point required for the center of mass of a single component, 2 points for constructing a single cylindrical component, 2 points for constructing a single tie rod component, 3 points for constructing a single triangular prism component, and 2 points for constructing a single rectangular component.

6. The optimization method of the unmanned aerial vehicle cabin door retracting and extending mechanism according to claim 1, characterized in that: The S3 includes: S3-1: Form a point coordinate matrix X based on the point coordinates: In formula (1), x1 represents the x-axis coordinate of the first point; y1 represents the y-axis coordinate of the first point; z1 represents the z-axis coordinate of the first point; n Indicates the x-axis coordinate of the nth point; y n Indicates the y-axis coordinate of the nth point; z n Indicates the z-axis coordinate of the nth point; S3-2: parameterize the original point coordinate matrix and determine the design variables DVi, i = 1, 2, ..., 15; S3-3: Establish a parametric model based on design variables: Use the design variables of the points to draw regular shapes, and use the points of the connection pairs to establish connection pairs between the various components, so as to perform parametric modeling of the hatch door retraction and extension mechanism.

7. The optimization method of the unmanned aerial vehicle cabin door retracting and extending mechanism according to claim 6, characterized in that: The S3-2 includes: S3-2-1: Identify the related points, and then perform parameterization to determine the design variables DVi, i = 1, 2, ..., 15; S3-2-2: Set the valid value range for the design variables: DVi+30≥DVi≥DVi-30, i=1,2,...,15 (2) In formula (2), DVi represents the i-th design variable.

8. The method for optimizing the door retracting and extending mechanism of a drone as claimed in claim 1, characterized in that: The S5 includes: S5-1: Construct the length constraint function of each component in the hatch retracting and extending mechanism: In formula (3), g1(X) represents the length constraint function of each component of the door retracting and releasing mechanism; n represents the number of components, L i (X) represents the length of the i-th component; L i,min represents the minimum length of the i-th component; S5-2: Construct the angle limit constraint function of the hatch door retracting and extending mechanism: g2(X)=θ(X)-θ max ≤0 (4) In formula (4), g2(X) represents the angle limit constraint function of the door retracting and releasing mechanism; θ(X) represents the door rotation angle; θ max Indicates the maximum rotation angle of the door; S5-3: Construct the space restriction constraint function of the hatch door retracting and extending mechanism: In formula (5), g3(X) represents the space restriction constraint function of the door retracting and releasing mechanism point; m represents the number of contact forces; CONTACT(X) i represents the i-th contact force.

9. The optimization method of the unmanned aerial vehicle cabin door retracting and extending mechanism according to claim 8, characterized in that: In S5-2, the maximum rotation angle of the door is θ max Not greater than 100°, i.e. θ max -100≤0.

10. The method for optimizing the door retracting and extending mechanism of a drone as claimed in claim 1, characterized in that: In S6, the objective function is: In formula (6), F 1,x (X), F 1,y (X), F 1,z (X) respectively represent the x-axial force component, y-axial force component and z-axial force component of the connection joint between the landing gear and the door retraction mechanism.

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