Undercarriage and unmanned aerial vehicle

Abstract

The undercarriage comprises a first platform, a second platform, a supporting assembly, a topographic measurement unit and / or an attitude detection unit, and the first platform is used for being connected with a fuselage of the unmanned aerial vehicle; the second platform is arranged on the lower side of the first platform; each supporting assembly comprises a supporting leg and a connecting rod mechanism, and each supporting leg is rotationally connected with the second platform; each supporting leg can rotate so that each supporting leg can make contact with the target landing area; angles of revolute pairs of all the connecting rod mechanisms can be adjusted so that the first platform can be horizontally arranged, and the projection of the gravity center of the unmanned aerial vehicle in the gravity direction is located in a target range. According to the landing gear, the angles of the supporting legs can be adjusted according to the terrain of a target landing area, so that the supporting legs are kept in contact with the target landing area; the position and inclination angle of the first platform can be adjusted through the connecting rod mechanism, so that the gravity center of the unmanned aerial vehicle is stable, and complex terrain adaptability and take-off and landing stability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles, and particularly to a landing gear and an unmanned aerial vehicle. Background Art

[0002] Due to its simple structure and flexible control, unmanned aerial vehicles have broad application prospects in many fields such as urban logistics, agricultural plant protection, emergency rescue, surveying and mapping. In related technologies, the landing gear of unmanned aerial vehicles usually adopts a fixed or semi-fixed structure, which is difficult to adapt to takeoff and landing on complex terrains, especially when operating on irregular or dynamic platforms such as building gaps in urban environments, mountainous hills, and ship decks; traditional landing gears have problems of insufficient stability and weak buffering performance, which severely restrict the application range and operation efficiency of unmanned aerial vehicles. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a landing gear that can adjust the angles of the support feet according to the terrain of the target landing area so that each support foot remains in contact with the target landing area; and can adjust the position and inclination angle of the first platform through a linkage mechanism to stabilize the center of gravity of the unmanned aerial vehicle and improve the adaptability to complex terrains and the stability of takeoff and landing.

[0004] The present invention also discloses an unmanned aerial vehicle having the above landing gear

[0005] In a first aspect, an embodiment of the present application provides a landing gear, including:

[0006] A first platform for connecting with the fuselage of the unmanned aerial vehicle;

[0007] A second platform disposed on the lower side of the first platform;

[0008] At least three sets of support components, each support component including a support foot and a linkage mechanism, each support foot being rotatably connected to the second platform; one end of each linkage mechanism is connected to the corresponding support foot, and the other end of each linkage mechanism is connected to the first platform to form a support point;

[0009] The landing gear further includes a terrain measurement unit, the terrain measurement unit being connected to the first platform or the second platform, the terrain measurement unit being configured to obtain terrain information of the target landing area and send it to the control unit for the control unit to calculate the support angles of the support feet according to the terrain information and control each support foot to rotate to the corresponding support angle so that each support foot is in contact with the target landing area; and / or,

[0010] The landing gear further includes an attitude detection unit, which is connected to the first platform. The attitude detection unit is configured to obtain the position information and attitude information of the first platform when the outrigger contacts the target landing area, and send them to the control unit, so that the control unit calculates the target angles of the rotating pairs of the link mechanisms and controls the rotating pairs of the link mechanisms to rotate to the corresponding target angles, so that the first platform is horizontally arranged, and the projection of the center of gravity of the UAV along the direction of gravity is within the target range. The target range is surrounded by connecting the ends of the outriggers away from the second platform in sequence along the circumference.

[0011] The landing gear according to the embodiment of the present invention has at least the following beneficial effects: by the terrain measurement unit, the terrain data is obtained in real time and the support angles of the outriggers are adjusted, and combined with the attitude detection unit to control the angles of the rotating pairs of the link mechanisms, so that the projection of the center of gravity of the UAV is stably within the support area, effectively solving the problems of poor adaptability of the landing gear and center of gravity deviation in complex terrains, and having the advantages of improving the terrain adaptability and attitude stability.

[0012] According to the first aspect, in a possible implementation manner, the terrain information includes terrain three-dimensional point cloud data. The control unit calculates the support angles of the outriggers according to the terrain information and controls the outriggers to rotate to the corresponding support angles, including:

[0013] Analyze the terrain three-dimensional point cloud data and extract terrain feature parameters;

[0014] Calculate the theoretical support area based on the terrain feature parameters;

[0015] According to the coordinate information of the theoretical support area, combined with the structural constraints of each outrigger, solve the target support angles of the outriggers through a multi-objective optimization algorithm

[0016] According to the first aspect, in a possible implementation manner, the control unit calculates the target angles of the rotating pairs of the link mechanisms, including:

[0017] Calculate the target coordinate information of the reference point according to the coordinate information of the contact points of the outriggers with the target landing area; the reference point is the projection position of the center of gravity of the UAV when the first platform is horizontal;

[0018] Calculate the target coordinate information of each support point according to the target coordinate information of the reference point and the structural parameters of the first platform;

[0019] According to the current coordinate information and target coordinate information of each support point, use kinematic inverse solution under the structural parameters of the link mechanism to calculate the target angles of the rotating pairs of the link mechanisms.

[0020] According to a first aspect, in a possible implementation, the link mechanism includes a transfer link and at least two support links. Two adjacent support links are rotatably connected along a first axis. The support link at one end is rotatably connected to the support leg along a second axis; the support link at the other end is rotatably connected to the transfer link along a third axis; the first axis, the second axis, and the third axis are arranged in parallel;

[0021] The transfer link is rotatably connected to the first platform along a fourth axis, and the fourth axis is perpendicular to the first axis.

[0022] According to a first aspect, in a possible implementation, the support leg has a free end, and the support link connected to the support leg has a receiving space with an opening facing the free end. The support leg is configured to: rotate relative to the second platform so that the free end disengages from the receiving space and exposes at the bottom of the second platform, or be received in the receiving space.

[0023] According to a first aspect, in a possible implementation, the first platform includes at least four first load-bearing links, and at least four of the first load-bearing links are rotatably connected end to end to form a polygonal structure; the second platform includes a plurality of second load-bearing links, and a plurality of the second load-bearing links are rotatably connected end to end to form a polygonal structure. The number of the second load-bearing links is the same as the number of the first load-bearing links; the second platform is configured to: adjust the included angle between two adjacent load-bearing links according to the terrain information of the target landing area.

[0024] According to a first aspect, in a possible implementation, the number of the support assemblies is the same as the number of the first load-bearing links. The link mechanisms are connected to the apex angles of the first platform in a one-to-one correspondence, and the support legs are connected to the apex angles of the second platform in a one-to-one correspondence.

[0025] According to a first aspect, in a possible implementation, the number of the support assemblies is the same as the number of the first load-bearing links. The link mechanisms are connected to the apex angles of the first platform in a one-to-one correspondence, and the support legs are connected to the apex angles of the second platform in a one-to-one correspondence.

[0026] According to a first aspect, in a possible implementation, two adjacent first load-bearing links are rotatably connected by a first rotating shaft, and the link mechanism is rotatably connected to the first rotating shaft; or a first adapter is rotatably connected to the first rotating shaft, and the link mechanism is rotatably connected to the first adapter;

[0027] Two adjacent second load-bearing links are rotatably connected by a second rotating shaft, and the support leg is rotatably connected to the second rotating shaft; or a second adapter is rotatably connected to the second rotating shaft, and the support leg is rotatably connected to the second adapter.

[0028] In a third aspect, an embodiment of the present application further provides a drone, which further includes a fuselage and the landing gear according to the second aspect, and the fuselage is connected to the first platform.

[0029] The drone according to the embodiment of the present invention has at least the following beneficial effects: By applying the above landing gear, the terrain measurement unit is used to obtain terrain data in real time and adjust the support angle of the feet, and the attitude detection unit is combined to control the angle of the rotating pair of the link mechanism, so that the center of gravity projection of the drone is stably within the support area, effectively solving the problems of poor adaptability of the landing gear and center of gravity offset in complex terrains, and having the advantages of improving terrain adaptability and attitude stability.

[0030] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the drawings and embodiments, where:

[0032] Figure 1 is a schematic structural diagram of a state of the landing gear in an embodiment of the present invention;

[0033] Figure 2 is a schematic structural diagram of another state of the landing gear in an embodiment of the present invention;

[0034] Figure 3 is a schematic top view structural diagram of a state of the landing gear in an embodiment of the present invention;

[0035] Figure 4 is a schematic top view structural diagram of another state of the landing gear in an embodiment of the present invention.

[0036] Reference numerals:

[0037] 1000, landing gear; 100, first platform; 110, first load-bearing link; 200, second platform; 210, second load-bearing link; 300, support assembly; 310, feet; 320, link mechanism; 321, transfer link; 322, support link; 323, accommodation space; 400, terrain measurement unit; 500, attitude detection unit; 610, first rotating shaft; 620, second rotating shaft; L1, first axis; L2, second axis; L3, third axis; L4, fourth axis. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0039] In the description of the present invention, it should be understood that with respect to the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or positional relationship shown in the accompanying drawings. It is 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 should not be construed as a limitation of the present invention.

[0040] In the description of the present invention, the meaning of several is more than one, the meaning of multiple is more than two, and greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0041] In the description of the present invention, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meaning of the above words in the present invention in combination with the specific content of the technical solution.

[0042] In the description of the present invention, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0043] In the prior art, most of the landing gears of unmanned aerial vehicles adopt fixed or semi-fixed structures. Such structures have problems of poor support stability and insufficient buffering capacity when facing complex terrains such as gaps between urban buildings, mountainous hills, or ship decks. The fixed landing gear cannot automatically adjust the support attitude according to the ground undulation, resulting in easy tilting or slipping of the fuselage during landing. Although the semi-fixed structure can limitedly adjust the support height, it lacks the real-time perception ability of the three-dimensional characteristics of the terrain and is difficult to achieve coordinated leveling of multiple legs. For example, when landing on an uneven rock surface, the traditional landing gear may have one-sided legs suspended or local overload, seriously affecting the landing safety.

[0044] To solve the above problems, the R & D personnel found that the fixed structure could not meet the requirements of adapting to complex terrains, so they turned to explore a dynamic adjustment mechanism. By analyzing the relationship between terrain features and support stability, it was proposed to design the outriggers as multi-degree-of-freedom adjustable structures. To solve the problems of terrain perception and attitude control, a dual feedback system of terrain measurement and attitude detection was introduced. Based on the multi-body dynamics model, the coupling relationship between the outrigger angle and the center of gravity position was established, and finally a closed-loop control system with active terrain adaptation ability was formed.

[0045] This application proposes a landing gear, as Figure 1 and Figure 2 shown. In some embodiments, the landing gear 1000 includes a first platform 100, a second platform 200, a support assembly 300, a terrain measurement unit 400, and an attitude detection unit 500. The first platform 100 is used to connect the drone fuselage, and the second platform 200 is located below the first platform 100. The support assembly 300 includes outriggers 310 and a linkage mechanism 320. The outriggers 310 are rotatably connected to the second platform 200; one end of each linkage mechanism 320 is connected to the corresponding outrigger 310, and the other end of each linkage mechanism 320 is connected to the first platform 100 to form a support point. The terrain measurement unit 400 acquires the terrain information of the target landing area and transmits it to the control unit. The target landing area can be the ground, a roof, or a ship deck, etc. The control unit calculates the support angle of the outriggers 310 and controls them to rotate to the corresponding angles so that the outriggers 310 contact the target landing area. The attitude detection unit 500 acquires the position information and attitude information of the first platform 100. The control unit calculates the target angles of the rotating pairs of the linkage mechanism 320 and adjusts the first platform 100 to be horizontally set, and the center of gravity of the drone is projected within the target range enclosed by the outriggers 310.

[0046] Among them, the first platform 100 refers to the basic structure that bears the drone fuselage. The second platform 200 refers to the dynamic adjustment carrier located below the first platform 100. The outriggers 310 in the support assembly 300 refer to the support components that directly contact the target landing area and are connected to the second platform 200 through rotating pairs to fit the undulations of the target landing area. The linkage mechanism 320 refers to the transmission structure that connects the first platform 100 and the outriggers 310. Specifically, a multi-link hinge mechanism can be adopted to adjust the spatial pose of the outriggers 310 by changing the angles of the rotating pairs. The terrain measurement unit 400 refers to the sensor assembly that acquires the three-dimensional terrain data. Specifically, a lidar or a stereo vision system can be adopted to extract the terrain slope and concave-convex feature parameters through point cloud data processing. The attitude detection unit 500 refers to the sensing device that monitors the platform pose. Specifically, a fusion system of an inertial measurement unit and GPS can be adopted to output the three-dimensional coordinates and attitude angle data of the platform in real time.

[0047] Specifically, when the terrain measurement unit 400 scans the landing area, three-dimensional point cloud data containing elevation information is generated. The control unit analyzes the point cloud data to extract slope change features and calculates the required support angles for each leg 310 to avoid suspension or overload. The legs 310 rotate around the second platform 200 according to the instructions to adjust to the target angles, so that the ends of all the legs 310 form stable contact with the target landing area. After the legs 310 contact the target landing area, the attitude detection unit 500 monitors the tilt angle and horizontal displacement of the first platform 100 in real time. The control unit constructs a polygon stable area based on the contact point coordinates of the legs 310 and reversely calculates the target angles of the rotating pairs of each linkage mechanism 320. By driving the adjustment of the rotating pairs of the linkage mechanism 320, the projection of the center of gravity of the UAV on the horizontal plane is always within the polygon area. The terrain measurement and attitude detection form a double closed-loop control, with the former ensuring the physical matching of the legs 310 with the terrain and the latter maintaining the dynamic balance of the center of gravity.

[0048] Through the above technical solutions, when the UAV in this application lands on complex terrain, each leg 310 can actively adapt to the undulation of the target landing area to form a stable support, avoiding the tipping risk caused by unilateral suspension. By adjusting the platform attitude in real time, it is ensured that the center of gravity of the UAV is always within the support area of the legs 310, improving the stability of the dynamic landing process. The coordinated control of terrain measurement and attitude detection realizes the precise matching of the shape of the landing gear 1000 and the terrain features, enhancing the landing reliability on inclined and uneven surfaces. The multi-degree-of-freedom design of the legs 310 and the linkage mechanism 320 enables the landing gear 1000 to cope with terrain changes in different directions, expanding the adaptability of the UAV's operating environment.

[0049] In this embodiment, it is achieved by the signal connection between the landing gear 1000 and the control unit of the UAV. In other embodiments, an independent control unit can also be designed for the landing gear 1000; the control unit can specifically adopt a flight control chip, an embedded computer platform, a PLC (programmable logic controller), etc.; this application does not make any limitations in this regard.

[0050] In some embodiments, the terrain information includes terrain three-dimensional point cloud data. The control unit calculates the support angles of each leg 310 according to the terrain information and controls each leg 310 to rotate to the corresponding support angle, including: analyzing the terrain three-dimensional point cloud data, extracting terrain feature parameters; calculating the theoretical support area based on the terrain feature parameters; according to the coordinate information of the theoretical support area, combined with the structural constraints of each leg 310, solving the target support angles of each leg through a multi-objective optimization algorithm.

[0051] Among them, the three-dimensional terrain point cloud data refers to the set of three-dimensional coordinates of discrete points on the surface of the target landing area collected by lidar or depth camera. Specifically, point cloud registration algorithms can be used to spatially fuse multiple frames of scan data to form a complete terrain surface model. This data is used to accurately reflect the spatial curvature and undulation characteristics of the terrain, avoiding the defect that traditional two-dimensional height maps cannot represent complex terrains. Terrain feature parameters refer to quantitative indicators such as slope, curvature, and distribution of concave and convex regions extracted from the point cloud data. Specifically, the principal component analysis method can be used to calculate the local surface normal vector, and then the slope and curvature parameters can be deduced. These parameters are used to identify flat areas suitable for support and obstacle areas to be avoided in the terrain. The theoretical support area refers to the terrain sub-area that meets the contact conditions of the feet 310 screened based on the terrain feature parameters. Specifically, by setting slope thresholds and curvature thresholds, the point cloud data can be segmented into candidate support areas and non-support areas, and then the region growing algorithm is used to merge adjacent points to form a continuous support surface. This area is used to ensure that the feet 310 can effectively cover the effective contact range of the terrain after adjustment. The multi-objective optimization algorithm refers to an optimization solution method that simultaneously considers support stability, joint motion range limitations, and energy consumption. Specifically, genetic algorithms or particle swarm algorithms can be used, with the uniformity of the support forces of each foot 310 and the minimization of the total joint rotation angle as the objective function, and the kinematic constraints of the feet 310 as the boundary conditions for iterative solution. This algorithm is used to coordinate the motion parameters of multiple joints and avoid the risk of mechanical interference caused by single-objective optimization.

[0052] Specifically, after the three-dimensional terrain point cloud data is collected by the sensor, the control unit first performs noise reduction and feature extraction on it, and identifies flat areas with low slope and low curvature in the terrain as candidate support areas. Subsequently, based on the position of the UAV's center of gravity and the kinematic model of the feet 310, the set of possible contact points of each foot 310 in the candidate support area is calculated, and the theoretical support area that can form a stable support polygon is screened out. In this process, the maximum deployment angle of the feet 310 and the length limit of the link mechanism 320 are input into the optimization model as constraint conditions. Finally, the multi-objective optimization algorithm is used to solve the target support angle combination that makes the support force distribution the most uniform and the joint driving force the smallest under the premise of satisfying all mechanical constraints, and drive each foot 310 to synchronously adjust to the specified position.

[0053] Through the above technical solutions, the present application can dynamically plan the support positions of the feet 310 according to the three-dimensional terrain data, automatically generate an adjustment plan that meets mechanical constraints under complex terrain conditions, make each foot 310 accurately fit the target landing area, avoid landing failures caused by terrain recognition errors or motion interference, and significantly improve the landing stability of the UAV on dynamic or irregular platforms.

[0054] In some embodiments, the target coordinate information of the reference point is calculated based on the coordinate information of the contact points of each leg 310 with the target landing area. The reference point is the projected position of the center of gravity of the drone when the first platform 100 is horizontal. According to the target coordinate information of the reference point and the structural parameters of the first platform 100, the target coordinate information of each support point is calculated. Based on the current coordinate information and the target coordinate information of each support point, the target angles of the rotating pairs of each link mechanism 320 are obtained by inverse kinematic solution under the structural parameters of the link mechanism 320.

[0055] Among them, the target coordinate information of the reference point refers to the position coordinates of the center of gravity of the drone relative to the first platform 100 in the ideal balanced state. Specifically, it can be realized by combining the coordinate transformation algorithm with the data of the center of gravity position sensor. By converting the three-dimensional space coordinates to the reference coordinate system of the first platform 100, the geometric relationship between the contact points with the target landing area is established. The target coordinate information of the support point refers to the theoretical position coordinates of the connection between each support component 300 and the first platform 100. Specifically, it can be obtained by geometric modeling combined with the platform structural parameters. For example, it can be solved by using the geometric constraint equations of the multi-link mechanism 320. The inverse kinematic solution refers to the process of inversely deriving the joint angles based on the target position. Specifically, it can be realized by iterative calculation using the numerical optimization algorithm combined with the Jacobian matrix to ensure that the angles of each rotating pair meet the motion range limitations of the mechanical structure.

[0056] Specifically, after the terrain measurement unit 400 obtains the coordinates of the contact points of the legs 310 with the target landing area, first, the position of the contact point is converted to the coordinate system of the first platform 100 through the homogeneous coordinate transformation matrix, and the reference coordinates of the center of gravity projection are calculated. Subsequently, according to the polygon structure characteristics of the platform bearing surface, the three-dimensional coordinates that each support point should reach in the balanced state are determined by the method of spatial vector decomposition. Finally, based on the spatial vector difference between the current position and the target position of each support point, the kinematic equation of the link mechanism 320 is established, and the Newton-Raphson iteration method is used to solve the angle adjustment amount of each rotating pair, and precise angle adjustment is realized through the drive of the servo motor.

[0057] This application can accurately compensate for the position deviation of the support points caused by terrain undulation. By mathematical modeling, the center of gravity control requirements are transformed into specific mechanical structure adjustment parameters, ensuring that when the drone lands on complex terrains such as slopes and steps, the center of gravity of the fuselage is always within the support polygon area, avoiding the risk of overturning caused by the center of gravity offset. At the same time, through the inverse kinematic solution algorithm, the coordinated control of the multi-degree-of-freedom mechanism is realized, significantly improving the attitude adjustment accuracy and response speed.

[0058] In some embodiments, the linkage mechanism 320 includes a transfer link 321 and at least two support links 322. Two adjacent support links 322 are rotatably connected along a first axis L1. The support link 322 at one end is rotatably connected to the support leg 310 along a second axis L2, and the support link 322 at the other end is rotatably connected to the transfer link 321 along a third axis L3. The first axis, the second axis L2, and the third axis L3 are arranged in parallel. The transfer link 321 is rotatably connected to the first platform 100 along a fourth axis L4, and the fourth axis L4 is perpendicular to the first axis L1.

[0059] Among them, the transfer link 321 refers to a transition structure connecting the first platform 100 and the support link 322. Specifically, a hinge structure can be used to realize the rotational connection of the fourth axis L4. The perpendicular arrangement of the fourth axis L4 enables the transfer link 321 to have a rotational degree of freedom in the vertical plane. The support link 322 refers to a rigid rod forming a planar kinematic chain. Specifically, an aluminum alloy pipe can be used to realize the rotational connection of adjacent support links 322 along the first axis L1 through a revolute pair. The composite hinge structure formed by three parallel axes enables the support leg 310 to have the ability to adjust at multiple angles in the plane. The rotational connection between the support leg 310 and the support link 322 along the second axis L2 means that the root of the support leg 310 forms a single-degree-of-freedom hinge with the support link 322 through a pin shaft. Specifically, a bushing structure with a self-lubricating bearing can be used to realize low-friction rotation, enabling the support leg 310 to adjust the pitch angle around the second axis L2. The perpendicular arrangement of the fourth axis L4 between the first platform 100 and the transfer link 321 means that the rotational axes of the two form a spatial orthogonal relationship. Specifically, a cross-axis hinge structure can be used to realize the decoupling of the rotational directions, so that the horizontal adjustment of the support link 322 and the vertical adjustment of the transfer link 321 do not interfere with each other.

[0060] Specifically, the three parallel axes between the support links 322 form a planar kinematic chain, allowing the support leg 310 to swing at multiple angles in the horizontal plane to adapt to the undulation of the target landing area. The transfer link 321 is connected to the first platform 100 through a vertical axis, enabling the entire linkage mechanism 320 to adjust the height in the vertical plane and form the ability to adjust the spatial three-dimensional pose. When the support leg 310 contacts irregular terrain, the planar kinematic chain of the support link 322 adjusts the horizontal projection position of the support leg 310 through the coordinated rotation of the three parallel axes. The rotation of the transfer link 321 along the fourth axis L4 compensates for the height difference in the vertical direction. The two work together to achieve stable contact between the support leg 310 and the target landing area. While ensuring that the movement trajectories of each link are controlled, the composite hinge structure realizes the decoupling control of spatial movement through the orthogonal axis arrangement, maintaining both the structural rigidity of the landing gear 1000 in the deployed state and providing the multi-degree-of-freedom adjustment ability required to cope with terrain mutations.

[0061] This embodiment realizes the precise three-dimensional pose adjustment of the outriggers 310 in complex terrains, enabling each outrigger 310 to independently adapt to the local undulations of the target landing area and ensuring that all support points reliably contact the target landing area simultaneously. The composite hinge structure maintains structural stability while expanding the degrees of freedom of movement, preventing mechanism instability during the multi-degree-of-freedom adjustment process. The system of rotating pairs arranged along orthogonal axes makes the horizontal adjustment and vertical compensation movements independent of each other, avoiding movement interference during multi-directional adjustment in traditional structures and improving the terrain adaptation efficiency.

[0062] In some embodiments, the outrigger 310 has a free end, and the support link 322 connected to the outrigger 310 has a receiving space 323 with an opening facing the free end. The outrigger 310 is configured to rotate relative to the second platform 200 so that the free end disengages from the receiving space 323 and exposes at the bottom of the second platform 200, or is received in the receiving space 323.

[0063] Herein, the free end refers to the end portion of the outrigger 310 away from the rotation connection point with the second platform 200. Specifically, the rotation of the outrigger 310 around the second platform 200 can be realized by means of a hinge, thereby hiding the end of the outrigger 310 in the storage state. The receiving space 323 refers to the cavity structure formed inside the support link 322, which can be specifically realized by a groove or a hollow tubular structure. The opening direction matches the rotation trajectory of the outrigger 310 to ensure that the outrigger 310 can be completely embedded inside the cavity during storage. Being received in the receiving space 323 means that the outrigger 310 adjusts its angle by rotation so that the free end completely enters the cavity inside the support link 322. At this time, the outrigger 310 and the support link 322 form a compact assembly relationship.

[0064] Specifically, the outrigger 310 realizes rotational movement through the rotation connection point with the second platform 200. When the UAV needs to land, the outrigger 310 needs to be deployed. The outrigger 310 rotates outward around the rotation axis, and the free end disengages from the opening of the support link 322 and extends below the second platform 200 to form a support structure. When the UAV is in flight, the outrigger 310 needs to be stored. The outrigger 310 rotates in the reverse direction, and the free end re-enters the cavity inside the support link 322 along the opening direction until the outrigger 310 is completely embedded in the cavity. The opening direction of the support link 322 is consistent with the rotation path of the outrigger 310, so that the end of the outrigger 310 is always wrapped by the cavity during the storage process, avoiding exposure. Through the geometric constraints of the mechanical structure, the outrigger 310 forms a self-locking with the support link 322 in the storage state to prevent accidental deployment due to vibration.

[0065] Through the above technical scheme, the present application can effectively reduce the overall volume of the landing gear 1000 in the stowed state, and avoid damage to the support leg 310 due to exposure during transportation or flight; when the support leg 310 is deployed, it can directly break away from the cavity constraint through rotational movement, shorten the response time, and adapt to the support requirements of different terrains; the cavity of the support link 322 and the support leg 310 form a self-locking structure to ensure stability in the stowed state.

[0066] In some embodiments, please refer to Figure 3 and Figure 4 The first platform 100 includes at least four first bearing links 110, which are connected by end-to-end rotation to form a polygonal structure; the second platform 200 includes multiple second bearing links 210, which are connected by end-to-end rotation to form a polygonal structure, and the number of second bearing links 210 is consistent with the number of first bearing links 110; the second platform 200 is configured to adjust the angle between two adjacent bearing links according to the terrain information of the target landing area.

[0067] Among them, the first bearing link 110 refers to a rigid rod constituting the frame of the first platform 100, which is connected by rotating head and tail to form a polygonal structure, which can be specifically realized by hinge or shaft connection, and the overall shape of the platform is changed by changing the angle between each link. The second bearing link 210 refers to the frame rod of the second platform 200 corresponding to the first platform 100, and the number is the same as the first bearing link 110, forming a polygonal structure that can be adjusted in linkage, and the coordinated deformation of the upper and lower platforms can be realized by a synchronous drive device. Adjusting the angle between adjacent bearing links refers to dynamically controlling the rotation angle of the connection between adjacent second bearing links 210 according to the three-dimensional data of the terrain, which can be specifically realized by using a servo or a linear motor to drive the shaft, and the polygonal contour of the second platform 200 is changed by adjusting the angle.

[0068] Specifically, the polygonal structure of the first platform 100 is connected by the rotation of each first bearing link 110 to form a plane frame that can be unfolded or folded, providing a deformation basis for the overall structure. The second platform 200 uses the same number of second bearing links 210 to construct a corresponding polygonal frame, and by controlling the rotation angle between adjacent links, the second platform 200 can actively adjust its own shape according to the undulating characteristics of the terrain. After the terrain measurement unit 400 obtains the three-dimensional point cloud data of the target landing area, the control unit analyzes the curvature, slope and concave-convex features of the target landing area, calculates the angle required to be adjusted at each connection of the second platform 200, and drives the actuator to drive the second bearing link 210 to rotate around the rotating axis, so that the polygonal structure of the second platform 200 is deformed into a geometric shape that matches the terrain. Through the linkage adjustment of the upper and lower platforms, the positional relationship between the contact points of the support leg 310 and the target landing area can be adjusted to achieve adaptive fitting of the landing gear 1000 to complex terrain.

[0069] The present application further proposes a landing gear 1000 structure, wherein the number of support assemblies 300 is consistent with the number of first load-bearing links 110 , the link mechanisms 320 are connected one-to-one to the top corners of the first platform 100 , and the support legs 310 are connected one-to-one to the top corners of the second platform 200 .

[0070] Among them, the number of support assemblies 300 is consistent with the number of first load-bearing links 110, which means that each side of the polygonal frame corresponds to an independent support unit, for example, the four-bar linkage 320 corresponds to four groups of support assemblies 300. This configuration enables each structural node to obtain independent driving capabilities, avoiding uneven distribution of supporting forces. Among them, the connection at the top corner means that the linkage 320 is installed at the turning point of the polygonal platform, and can be specifically installed by the combination of the rotating shaft and the corner reinforcement structure. This layout transfers the load to the geometric node with the greatest structural strength, effectively preventing deformation caused by stress concentration. Among them, the corresponding connection between the support leg 310 and the top corner of the second platform 200 means that the pivot point of each support leg 310 is located at the polygonal corner point of the second platform 200, for example, connected at the platform corner by a universal joint. This design enables the support leg 310 to form the maximum support span when it is unfolded, while ensuring that the deformation of the second platform 200 can be fed back to the support leg 310 angle adjustment in real time through the rotating shaft mechanism.

[0071] Specifically, when the drone lands on an inclined ground, the first platform 100 transfers the load to the support assembly 300 through the link mechanism 320 at the apex. Since each apex is provided with an independent support assembly 300, the second platform 200 can automatically adjust the angles of the feet 310 at each corner during the unfolding process of the feet 310 according to the terrain undulation. For example, in a quadrilateral platform, the four feet 310 correspond to the four corners of the platform respectively. When the terrain is uneven, each foot 310 performs differential angle compensation according to the position of the corresponding corner, so that the second platform 200 forms a support surface matching the terrain curvature. Through the mapping relationship of apex to apex, the torque borne by the first platform 100 can be evenly distributed to each foot 310, avoiding local overload.

[0072] Taking the first platform 100 and the second platform 200 as a quadrilateral platform as an example for illustration, the link mechanisms 320 of the two support assemblies 300 located at the diagonals are arranged collinearly with the rotation axis of the first platform 100, and the link mechanisms 320 of the two support assemblies 300 located at two adjacent apexes are arranged perpendicular to the rotation axis of the first platform 100.

[0073] Among them, the collinear arrangement means that the rotation axes of the two link mechanisms 320 are located on the same straight line, and a symmetric support frame is formed through the axis coincidence layout to enhance the torsional stiffness of the landing gear 1000. Among them, the perpendicular arrangement means that the rotation axes of two adjacent groups of link mechanisms 320 form an orthogonal relationship, and this feature ensures the decoupling of movements in different directions through the axis orthogonal constraint, preventing spatial interference when multiple linkages are in motion.

[0074] Specifically, by setting the rotation axes of the two groups of link mechanisms 320 located at the diagonals to be collinear, the landing gear 1000 forms a symmetric support structure in the X-axis and Y-axis directions, so that the feet 310 on both sides of the drone can adjust the angles synchronously during landing, maintaining the symmetry of the center of gravity projection. The rotation axes of two adjacent groups of link mechanisms 320 are perpendicular, so that each foot 310 forms an orthogonal movement direction in the horizontal plane. When encountering an inclined terrain, the feet 310 in different directions can independently adjust the support angles without overlapping movement trajectories, thus eliminating the common movement interference problem of multi-degree-of-freedom mechanisms. Thus, while maintaining a symmetric layout, the four support assemblies 300 achieve the independence of movements in all directions through the orthogonal axis configuration, ultimately improving the attitude adjustment accuracy and structural stability of the landing gear 1000 in complex terrains.

[0075] In some embodiments, please refer to Figures 2 to 4, two adjacent first load-bearing linkages 110 are rotatably connected by a first rotating shaft 610, the linkage mechanism 320 is rotatably connected to the first rotating shaft 610, or the first rotating shaft 610 is rotatably connected with a first adapter, and the linkage mechanism 320 is rotatably connected to the first adapter; two adjacent second load-bearing linkages 210 are rotatably connected by a second rotating shaft 620, the support feet 310 are rotatably connected to the second rotating shaft 620, or the second rotating shaft 620 is rotatably connected with a second adapter, and the support feet 310 are rotatably connected to the second adapter.

[0076] Among them, the first rotating shaft 610 refers to the rotating component connecting two adjacent first load-bearing linkages 110, which can be specifically implemented by a pin shaft or a hinge structure, and is used to realize the relative rotation between the load-bearing linkages, providing rotational freedom for the adjustment of the polygonal structure of the first platform 100. The second rotating shaft 620 refers to the rotating component connecting two adjacent second load-bearing linkages 210, which can be specifically implemented by a rotating shaft with bearings, and is used to support the shape adjustment of the second platform 200 and at the same time provide a rotating fulcrum for the support feet 310. The first adapter refers to the connecting component attached to the first rotating shaft 610, which can be specifically implemented by an adapter block with mounting holes, and is used to increase the connection freedom between the linkage mechanism 320 and the rotating shaft, avoiding motion interference. The second adapter refers to the connecting component attached to the second rotating shaft 620, which can be specifically implemented by a U-shaped bracket, and is used to provide a multi-angle mounting position for the support feet 310 to adapt to the support angle requirements under different terrains.

[0077] Specifically, on the first platform 100, two adjacent first load-bearing linkages 110 are connected by a first rotating shaft 610 to form an adjustable polygonal frame. At this time, the linkage mechanism 320 can be directly connected to the first rotating shaft 610 to synchronously adjust its own angle following the rotation of the rotating shaft; or indirectly connected through the first adapter, so that the linkage mechanism 320 can still maintain an independent motion trajectory when the load-bearing linkages rotate. On the second platform 200, the support feet 310 can be directly connected to the second rotating shaft 620 to realize linkage angle adjustment based on the polygonal deformation of the second platform 200; or connected through the second adapter, so that the support feet 310 can obtain additional rotational freedom during the deformation of the second platform 200. This dual connection method enables the support assembly 300 to not only perform collaborative adjustment based on the overall shape change of the platform, but also achieve local fine adjustment through the additional freedom of the adapter, thus balancing the uniformity of the support point distribution and the flexibility of angle adjustment under complex terrains.

[0078] The present application further provides a drone, which includes a fuselage and a landing gear 1000, and the fuselage is connected to a first platform 100. Among them, the first platform 100 refers to a rigid connection interface for carrying the fuselage of the drone, and specifically, it can be implemented by an aluminum alloy frame combined with a multi-directional hinge mechanism. Its polygonal structure design allows for deformation compensation when stressed. The terrain measurement unit 400 refers to a detection module integrating a lidar or a binocular vision sensor, and specifically, it can adopt a configuration integrating a millimeter-wave radar and an inertial measurement unit to generate three-dimensional point cloud data by scanning the curvature characteristics of the target landing area. The support assembly 300 refers to an adjustable load-bearing structure including a support leg 310 and a multi-link mechanism 320. Specifically, it can adopt a parallel four-link mechanism 320 with four rotating pairs, and a pressure sensor is arranged at the end of the support leg 310 to feedback the contact state in real time. The attitude detection unit 500 refers to an inertial navigation system composed of a gyroscope and an accelerometer, and specifically, it can adopt a MEMS sensor array to judge the spatial pose of the platform by solving Euler angle data.

[0079] Through the above technical solutions, the present application enables the drone to automatically match the spacing of balcony guardrails when landing between buildings, adapt to the uneven rock surface when taking off and landing on mountains, and compensate for the displacement deviation caused by the hull sway in real time when operating on the ship deck. Through the deep integration of the landing gear 1000 and the flight control system, the static stability of the drone after landing on complex terrain is improved, the uniformity of the landing impact load distribution is improved, and the structural deformation amount under heavy load is controllable, effectively expanding its application boundaries in emergency rescue and special transportation scenarios.

[0080] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge scope of those of ordinary skill in the art. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A landing gear, characterized in that, Comprising: A first platform for connecting to the fuselage of a drone; A second platform provided on the lower side of the first platform; At least three sets of support components, each support component including a support leg and a linkage mechanism, each support leg being rotatably connected to the second platform; one end of each linkage mechanism is connected to the corresponding support leg, and the other end of each linkage mechanism is connected to the first platform to form a support point; The landing gear further includes a terrain measurement unit, the terrain measurement unit being connected to the first platform or the second platform, the terrain measurement unit being configured to obtain terrain information of a target landing area and send it to a control unit for the control unit to calculate the support angles of the support legs according to the terrain information and control each support leg to rotate to the corresponding support angle so that each support leg contacts the target landing area; And / or, The landing gear further includes an attitude detection unit, the attitude detection unit being connected to the first platform, the attitude detection unit being configured to obtain the position information and attitude information of the first platform when the support legs contact the target landing area and send it to the control unit for the control unit to calculate the target angles of the rotating pairs of the linkage mechanisms and control the rotating pairs of the linkage mechanisms to rotate to the corresponding target angles so that the first platform is horizontally arranged and the projection of the center of gravity of the drone along the direction of gravity is within a target range, the target range being surrounded by connecting the ends of the support legs away from the second platform in sequence along the circumferential direction.

2. The landing gear according to claim 1, characterized in that, The terrain information includes terrain three-dimensional point cloud data, and the control unit calculating the support angles of the support legs according to the terrain information and controlling each support leg to rotate to the corresponding support angle includes: Analyzing the terrain three-dimensional point cloud data to extract terrain feature parameters; Calculating a theoretical support area based on the terrain feature parameters; According to the coordinate information of the theoretical support area, combined with the structural constraints of each support leg, solving the target support angles of each support leg through a multi-objective optimization algorithm.

3. The landing gear according to claim 1, characterized in that, The control unit calculating the target angles of the rotating pairs of the linkage mechanisms includes; Calculating the target coordinate information of a reference point according to the coordinate information of the contact points of each support leg with the target landing area; the reference point is the projection position of the center of gravity of the drone when the first platform is horizontal; Calculating the target coordinate information of each support point according to the target coordinate information of the reference point and the structural parameters of the first platform; According to the current coordinate information and target coordinate information of each support point, using inverse kinematics to find the target angles of the rotating pairs of the linkage mechanisms under the structural parameters of the linkage mechanism.

4. The landing gear according to claim 1, characterized in that The linkage mechanism includes a transfer link and at least two support links, adjacent two support links being rotatably connected along a first axis, and the support link at one end being rotatably connected to the support leg along a second axis; The support link at the other end is rotatably connected to the transfer link along a third axis; the first axis, the second axis and the third axis are arranged in parallel; The transfer link is rotatably connected to the first platform along a fourth axis, and the fourth axis is perpendicular to the first axis.

5. The landing gear according to claim 4, characterized in that, The outrigger has a free end, and the support link connected to the outrigger has a receiving space with an opening facing the free end. The outrigger is configured to rotate relative to the second platform so that the free end disengages from the receiving space and exposes at the bottom of the second platform, or is received in the receiving space.

6. The landing gear according to claim 1, characterized in that, The first platform includes at least four first load-bearing links, and the at least four first load-bearing links are rotatably connected end to end to form a polygonal structure; the second platform includes a plurality of second load-bearing links, and the plurality of second load-bearing links are rotatably connected end to end to form a polygonal structure. The number of the second load-bearing links is the same as the number of the first load-bearing links; the second platform is configured to adjust the angle between two adjacent load-bearing links according to the terrain information of the target landing area.

7. The landing gear according to claim 6, characterized in that, The number of the support assemblies is the same as the number of the first load-bearing links. The link mechanisms are respectively connected to the apex angles of the first platform, and the outriggers are respectively connected to the apex angles of the second platform.

8. The landing gear according to claim 7, characterized in that, The number of the support assemblies is four. The link mechanisms of the two support assemblies located diagonally are collinear with the rotation axis of the first platform; the link mechanisms of the two support assemblies located at two adjacent apex angles are perpendicular to the rotation axis of the first platform.

9. The landing gear according to claim 7, characterized in that, Two adjacent first load-bearing links are rotatably connected by a first rotating shaft, and the link mechanism is rotatably connected to the first rotating shaft; or the first rotating shaft is rotatably connected with a first adapter, and the link mechanism is rotatably connected to the first adapter. Two adjacent second load-bearing links are rotatably connected by a second rotating shaft, and the outrigger is rotatably connected to the second rotating shaft; or the second rotating shaft is rotatably connected with a second adapter, and the outrigger is rotatably connected to the second adapter.

10. A drone, characterized in that, It includes a fuselage and the landing gear according to any one of claims 1 to 9, and the fuselage is connected to the first platform.

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