A flapping wing and its manta ray underwater vehicle with non-uniform cubic lattice packing

Abstract

The application discloses a flapping wing and device of non-uniform three-dimensional lattice filling, and relates to the technical field of bionic robots. The flapping wing comprises a whole support frame of the bionic flapping wing, a filler filled in the whole support frame, and a flexible skin covered on the surface of the whole support frame. The whole support frame comprises a central fin plate and a flexible rib plate support frame. The central fin plate is embedded in the flexible rib plate support frame. The flexible rib plate support frame is made of soft material. The filler is a three-dimensional non-uniform lattice body made of flexible material. The lattices in the three-dimensional non-uniform lattice body are arranged non-uniformly. The filler of the three-dimensional non-uniform lattice body is constructed by using an additive manufacturing method. The overall flexibility of the filler can be adjusted by adjusting the distribution position and distribution proportion of the three-dimensional lattices of different sizes, and the passive deformation degree of the whole bionic flapping wing can be adjusted more flexibly.

Description

Technical Field

[0001] This invention relates to the field of biomimetic robot technology, specifically to a flapping wing with non-uniform three-dimensional lattice filling and its manta ray-inspired underwater vehicle. Background Technology

[0002] Manta rays are marine fish that swim by flapping their pectoral fins. Compared to fish that use their tail fins for propulsion, manta rays' flattened bodies provide superior swimming stability, maneuverability, and propulsion efficiency. Their unique gliding-flapping integrated propulsion method has also provided a reference for the development of biomimetic underwater vehicles. Biomimetic underwater vehicles inspired by manta rays possess characteristics such as large payload capacity, stable navigation, high propulsion efficiency, and a wide operating range. They can be applied to scenarios such as marine ranching fish monitoring, wide-area hydrological big data collection, and waterway monitoring.

[0003] As a crucial propulsion mechanism and primary thrust source for manta ray-inspired underwater vehicles, the performance of the biomimetic flapping wing directly impacts the swimming performance of the vehicle. Without considering the influence of motion parameters, the shape and dynamic shape retention capability of the biomimetic flapping wing are critical to improving propulsion performance. Currently, there are two main methods for shape-preserving underwater biomimetic flapping wings. One existing technology discloses a method using a soft material such as silicone for integral casting to achieve shape preservation. The integral casting method achieves good shape preservation in both static and dynamic states, but it significantly increases the overall mass of the biomimetic flapping wing, placing higher demands on its drive mechanism.

[0004] Currently, methods for maintaining the shape of manta ray-inspired flapping wings in both static and dynamic applications are quite limited. Static shape retention typically involves a rigid frame covered with a flexible skin, often made of elastic nylon fabric. The frame is hollow and unfilled, providing good shape retention only in static conditions in air. During underwater movement, the elastic fabric deforms irregularly, and the rigid frame protrudes beyond the coverage of the elastic skin, making dynamic shape retention impossible. Another common dynamic shape retention method involves filling the flapping wings with soft materials like silicone. However, this significantly increases the mass of the flapping wings, posing new requirements for the wing's drive structure design. In conclusion, current shape retention solutions cannot simultaneously address static and dynamic shape retention, as well as lightweight and modular development requirements, thus limiting further improvements in the motion similarity and swimming performance of manta ray-inspired vehicles. Summary of the Invention

[0005] To address the shortcomings in the aforementioned background technology, and primarily to solve the shape retention problem of the flapping wing of the manta ray-inspired underwater vehicle under static and dynamic conditions, a non-uniform three-dimensional lattice-filled flapping wing and its manta ray-inspired underwater vehicle are provided. This flapping wing ensures the lightweight of the biomimetic flapping wing structure by filling the overall support frame of the biomimetic flapping wing with a non-uniform three-dimensional lattice, which is of great significance for improving the propulsion and swimming performance of the manta ray-inspired underwater vehicle.

[0006] To achieve the above objectives, the first objective of this invention is to provide a flapping wing with non-uniform three-dimensional lattice filling, comprising:

[0007] Bionic flapping wing integral support frame;

[0008] The filler material is filled within the overall support frame;

[0009] A flexible skin that covers the surface of the overall support frame;

[0010] The overall support frame includes a central fin plate and a flexible rib plate support frame;

[0011] The central fin plate is embedded in the flexible rib support frame;

[0012] The flexible rib support frame is made of a soft material;

[0013] The filler is a three-dimensional non-uniform lattice made of a flexible material;

[0014] The lattice in the three-dimensional non-uniform solid lattice is non-uniformly distributed.

[0015] Preferably, the size of the lattice in the three-dimensional non-uniform solid lattice is arranged from large to small along the direction of the overall support frame.

[0016] Preferably, the three-dimensional non-uniform solid lattice is prepared according to the following steps:

[0017] First, the three-dimensional lattice structure of the entire biomimetic flapping wing is designed and its distribution pattern is determined. The root and leading edge adopt a large lattice with thicker lattice edges and a larger lattice envelope volume. This lattice structure has greater rigidity. The thickness of the lattice edges and the envelope volume are gradually reduced along the trailing edge and wingtip of the flapping wing, that is, the rigidity is gradually reduced.

[0018] Then, the three-dimensional design of the non-uniform three-dimensional lattice structure was completed in the three-dimensional drawing software. To facilitate processing, the non-uniform three-dimensional lattice structure inside the bionic flapping wing was divided into several parts, processed separately, and finally spliced ​​together.

[0019] Finally, a three-dimensional lattice structure was fabricated using 3D printing additive manufacturing technology.

[0020] Among them, 3D printing can use FDM, SLA or Polyjet technology, and the crystal structure can adopt a regular hexahedral or regular tetrahedral crystal structure.

[0021] Preferably, the flexible rib support frame includes:

[0022] The upper and lower strip support plates are set opposite to each other;

[0023] A root support plate is provided between one end of the upper strip support plate and the lower strip support plate along their long sides, and a tip support plate is provided between the other ends; wherein, the distance between the upper strip support plate and the lower strip support plate at the root support plate is greater than the distance between them at the tip support plate.

[0024] Between the upper strip support plate and the lower strip support plate, a plurality of elliptical support ribs are arranged sequentially from the root support plate to the tip support plate; wherein the perimeter of the plurality of elliptical support ribs arranged sequentially from the root support plate to the tip support plate decreases sequentially.

[0025] The major axis of each elliptical support rib is parallel to the upper or lower strip support plate; each elliptical support rib is rotatably connected to both the upper and lower strip support plates.

[0026] More preferably, each of the elliptical support ribs has notches at both ends along its long axis; these notches allow the front and rear edges of the central fin to be inserted, and provide a gap for relative movement between the central fin and each of the elliptical support ribs.

[0027] Preferably, the outer contour surface of the filler is higher than the boundary of the overall support frame, the filler is in clearance fit with the flexible rib support frame, and is fixedly connected to the central fin.

[0028] More preferably, the flexible skin is prepared from a soft material using an integral casting method; the flexible skin is bonded to the contour surface of the filler.

[0029] Preferred options also include:

[0030] Bionic flapping wing fixing bracket;

[0031] A drive device is mounted on the biomimetic flapping wing fixing bracket;

[0032] The drive device is used to drive the central fin plate to swing, and to drive the flexible rib support frame to swing.

[0033] Preferably, the central fin plate adopts the skeletal form of the pectoral fin of a manta ray.

[0034] The second objective of this invention is to provide a manta ray-inspired underwater vehicle, comprising the aforementioned flapping wings filled with a non-uniform three-dimensional lattice.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] This invention provides a non-uniform three-dimensional lattice-filled flapping wing, mainly composed of a flexible biomimetic flapping wing overall support frame, a three-dimensional non-uniform lattice filler, and a flexible skin. The overall support frame provides basic support for the biomimetic flapping wing and ensures that it does not affect the active and passive deformation of the biomimetic flapping wing. Based on this, the three-dimensional non-uniform lattice filler is constructed using additive manufacturing to fill the gaps in the overall support frame. The design of the lattice filler surface being higher than the support frame ensures the continuity of the flapping wing's surface during static and dynamic deformation. Compared to a three-dimensional uniform lattice filler, the three-dimensional non-uniform lattice used in this invention is composed of two or more different scales of three-dimensional non-uniform lattices. The overall flexibility of the filler component can be adjusted by regulating the distribution position and proportion of lattices of different scales, thereby allowing for more flexible adjustment of the passive deformation degree of the biomimetic flapping wing. This further improves the motion similarity of the flapping wing during static and dynamic deformation.

[0037] This invention covers the outer surface of the lattice-filled component with a flexible skin, which further enhances the integrity and continuity of the flapping wing's surface during static and dynamic deformation. Improving the integrity and continuity of the flapping wing's surface helps enhance the static and dynamic similarity of the manta ray-inspired vehicle, strengthening its stealth capabilities and environmental adaptability. Simultaneously, it helps improve the propulsion performance and efficiency of the manta ray-inspired vehicle, which is significant for enhancing its swimming performance and operational range. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the overall shape-preserving scheme of the biomimetic flapping wing of the present invention.

[0039] Figure 2 This is a schematic diagram of the overall frame support structure of the biomimetic flapping wing according to an embodiment of the present invention.

[0040] Figure 3 This is a schematic diagram of the flexible rib support frame structure according to an embodiment of the present invention.

[0041] Figure 4 This is a schematic diagram of a three-dimensional non-uniform lattice-filled component according to an embodiment of the present invention.

[0042] Figure 5 This is a schematic diagram of the central fin plate in an embodiment of the present invention.

[0043] Figure 6 This is a schematic diagram of the biomimetic flapping wing flexible skin of an embodiment of the present invention.

[0044] Figure 7 This is a schematic diagram of a non-uniform three-dimensional lattice according to an embodiment of the present invention.

[0045] Explanation of reference numerals in the attached drawings: 1—Bionic flapping wing overall support frame, 2—Bionic flapping wing flexible skin, 3—Filling material, 11—First-stage torsion motor, 12—Second-stage flapping motor, 13—Flexible rib support frame, 14—Central fin, 15—Bionic flapping wing fixing bracket, 16—Second-stage flapping motor output shaft, 17—Central fin adapter fixing plate, 131—First-stage chordal support rib, 132—Second-stage chordal support rib, 133—Third-stage chordal support rib, 134—Fourth-stage chordal support rib, 135—Root support rib, 136—Upper spanwise support rib, 137—Lower spanwise support rib, 138—Slight support rib. Detailed Implementation

[0046] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the present invention.

[0047] This invention provides a flapping wing with non-uniform three-dimensional lattice filling, see [link / reference]. Figures 1-6 As shown, it includes: a biomimetic flapping wing integral support frame 1, filler 3, and flexible skin 2; filler 3 fills the integral support frame; flexible skin 2 covers the surface of the integral support frame; the integral support frame 1 includes a central fin plate 14 and a flexible rib support frame 13; the central fin plate 14 is embedded in the flexible rib support frame 13; the flexible rib support frame 13 is made of a soft material; the filler 3 is a three-dimensional non-uniform solid lattice made of flexible material; the lattice in the three-dimensional non-uniform solid lattice is non-uniformly distributed. The central fin plate 14 adopts the skeletal form of the pectoral fin of a manta ray.

[0048] This invention draws inspiration from the skeletal-muscle-skin structure of biological pectoral fins, decomposing the biomimetic flapping wing into three components: first, a biomimetic flapping wing overall support frame corresponding to the skeletal structure of biological pectoral fins; second, a three-dimensional non-uniform lattice flapping wing filler corresponding to the muscles of biological pectoral fins; and third, a biomimetic flapping wing flexible skin corresponding to the skin of biological pectoral fins. The overall support frame of the biomimetic flapping wing mainly consists of a rigid central fin plate and a flexible rib support frame. The central fin plate is connected to the output shaft of the biomimetic flapping wing drive motor via flange connections, key connections, spline connections, and threaded connections to ensure no relative rotation or sliding between the central fin plate and the drive motor output shaft. The central fin plate is embedded within the flexible rib support frame, ensuring relative displacement between the central fin plate and the flexible rib support frame. When the biomimetic flapping wing flaps underwater, the curvature of the upper and lower surfaces will differ, further causing different compression and stretching amounts on the upper and lower surfaces. The relative displacement between the central fin plate and the flexible rib support frame can reduce or avoid interference with the deformation of the biomimetic flapping wing, ensuring the continuity of the biomimetic flapping wing's deformation.

[0049] To improve the similarity of the shape and the propulsion efficiency of the biomimetic flapping wing, a flexible skin is covered on the outside of the three-dimensional non-uniform lattice filling component. The flexible skin completely wraps the filling component and the support frame, isolating the internal and external fluids of the biomimetic flapping wing. This can prevent relative flow between the internal and external fluids of the flapping wing and thus avoid affecting the propulsion performance. At the same time, the flexible skin ensures the integrity of the flapping wing's movement.

[0050] In this embodiment, the size of the lattice in the three-dimensional non-uniform solid lattice is arranged from large to small along the direction of the overall support frame 1. The root and leading edge use large lattices with thicker lattice edges and larger lattice envelope volumes. In this embodiment, a regular hexahedral lattice is used.

[0051] In this embodiment, the three-dimensional non-uniform lattice filler is a flexible material with a lattice structure that is a spatially uniform grid with obvious regularity. Adjacent lattices share the same edge. The interior of the three-dimensional non-uniform lattice filler contains a space reserved for the overall support frame and the central fin. The outer contour surface of the three-dimensional non-uniform lattice filler can be adjusted according to the overall shape of the flapping wing, and the outer contour surface is higher than the boundary of the overall support frame. It can move with the flapping wing as a whole under the action of the central fin and the overall support frame, and undergo elastic deformation under the action of fluid.

[0052] Specifically, the three-dimensional non-uniform solid lattice is prepared according to the following steps:

[0053] First, based on the distribution patterns of pectoral fin muscles and skeletal calcification in biological pectoral fins—that is, generally exhibiting a distribution pattern from the leading edge to the trailing edge, and from the wing root to the wingtip, with muscle thickness gradually decreasing and skeletal calcification gradually decreasing—the three-dimensional lattice structure of the entire biomimetic flapping fin was designed, and its distribution pattern was determined. In this embodiment, the root and leading edge use large lattices with thicker lattice edges and larger lattice envelope volumes, while the thickness of the lattice edges and the envelope volume gradually decrease along the trailing edge and wingtip of the flapping fin.

[0054] Then, the 3D design of the non-uniform solid lattice structure was completed in 3D modeling software. To facilitate fabrication, the non-uniform solid lattice structure inside the biomimetic flapping wing was divided into several parts, which were fabricated separately and then finally assembled. See [link / reference] Figure 7 The diagram shows a non-uniform three-dimensional lattice.

[0055] Finally, a three-dimensional lattice structure is fabricated using 3D printing additive manufacturing technology. In this embodiment, Polyjet technology is used, and the lattice adopts a regular hexahedral lattice.

[0056] In this embodiment, the three-dimensional non-uniform lattice filler is fabricated using additive manufacturing and is divided into upper and lower parts for easy assembly. Similarly, the three-dimensional non-uniform lattice filler and the support frame still use a gap fit, but the three-dimensional non-uniform lattice filler and the central fin are fixedly connected. This fit ensures that the motion transmitted from the central fin can be quickly, continuously, and without impact to the surface of the bionic flapping wing, while also ensuring that the support frame does not restrict the active and passive deformation of the bionic flapping wing. In this embodiment, the flapping wing adopts the NACA00 series airfoil, and the external surface of the three-dimensional non-uniform lattice filler component is higher than the overall support frame to ensure the integrity and continuity of the bionic flapping wing in both static and dynamic states.

[0057] To further illustrate the overall support frame, the flexible rib support frame 13 includes:

[0058] An upper strip support plate and a lower strip support plate are arranged opposite each other; a root support plate is provided between one end of the upper strip support plate and the lower strip support plate along the long side direction, and a tip support plate is provided between the other ends; wherein, the distance between the upper strip support plate and the lower strip support plate at the root support plate is greater than the distance between the upper strip support plate and the lower strip support plate at the tip support plate;

[0059] Between the upper strip support plate and the lower strip support plate, multiple elliptical support ribs are arranged sequentially from the root support plate to the tip support plate; wherein, the circumference of the multiple elliptical support ribs arranged sequentially from the root support plate to the tip support plate decreases sequentially.

[0060] The major axis of each elliptical support rib is parallel to either the upper or lower strip support plate; each elliptical support rib is rotatably connected to both the upper and lower strip support plates.

[0061] In this embodiment, see Figure 3 As shown, the upper spanning support rib 136 is called the upper strip support plate, the lower spanning support rib 137 is called the lower strip support plate, the root support rib 135 is called the root support plate, the tip support rib 138 is called the tip support plate, and the multiple elliptical support ribs are called multiple chordal support ribs. Among them, from the root support plate to the tip support plate, the first-level chordal support rib 131, the second-level chordal support rib 132, the third-level chordal support rib 133, and the fourth-level chordal support rib 134 are arranged in sequence.

[0062] Each elliptical support rib has notches at both ends along its long axis; these notches allow the front and rear edges of the central fin plate 14 to be inserted, and provide gaps for relative movement between the central fin plate 14 and each elliptical support rib.

[0063] In this embodiment, the central fin 14 and the flexible rib support frame 13 are connected by primary, secondary, tertiary, and quaternary chordal support ribs distributed along the spanwise direction. The central fin is made of a homogeneous rigid material of uniform thickness through machining, while the flexible rib support frame is made of a soft material through machining and additive manufacturing. Each chordal rib has notches at its leading and trailing edges, allowing the leading and trailing edges of the central fin to engage and permitting relative displacement between the central fin and the chordal ribs. When the biomimetic flapping fin flaps underwater, it undergoes passive deformation, resulting in different curvatures on its upper and lower surfaces. Without this relative displacement, the flapping fin's bending deformation would be limited, hindering the improvement of propulsion force and efficiency. Similarly, the flexible rib support frame consists of several spanwise support ribs, chordally support ribs, and root and tip support ribs. The ribs are connected by cylindrical pairs to ensure that they can rotate and slide relative to each other, thus avoiding interference with the passive bending deformation of the bionic flapping wing.

[0064] It should be noted that the gaps in the overall support frame of the biomimetic flapping wing are filled using a three-dimensional non-uniform lattice structure. The overall shape of the filling component, composed of the three-dimensional non-uniform lattice structure, is higher than that of the flexible rib support frame. The biomimetic flapping wing profile is obtained by lofting several standard airfoil sections. The three-dimensional non-uniform lattice filling material ensures the integrity and continuity of the profile when the flapping wing undergoes dynamic deformation. Therefore, the outer contour surface of the filling material 3 is set higher than the boundary of the overall support frame. The filling material 3 is clearance-fitted with the flexible rib support frame 13 and is fixedly connected to the central fin plate 14.

[0065] In this embodiment, the provided flapping fin with non-uniform three-dimensional lattice filling further includes:

[0066] Bionic flapping wing fixing bracket 15; drive device, which is set on the bionic flapping wing fixing bracket 15; the drive device is used to drive the central fin plate 14 to swing, and drive the flexible rib support frame 13 to swing.

[0067] The drive device includes a primary torsion motor 11, which is mounted on the bionic flapping wing fixing bracket 15. A secondary flapping motor 12 is mounted on the output shaft of the primary torsion motor 11. The output shaft 16 of the secondary flapping motor 12 is fixedly connected to the end of the central fin plate 14 near the root support plate by a fixing plate 17. Therefore, the primary torsion motor 11 drives the secondary flapping motor 12 to twist back and forth, and the secondary flapping motor 12 drives the central fin plate 14 to swing up and down.

[0068] In this embodiment, the flexible skin 2 is prepared by integral casting of soft material; the flexible skin 2 is bonded to the contour surface of the filler 3.

[0069] The flexible skin 2 is fabricated from a soft material using a monolithic casting method. In this embodiment, the flexible skin is made of silicone. After assembling the overall support frame and the three-dimensional non-uniform lattice filling component, an organic solvent is used to bond the flexible skin to the three-dimensional non-uniform lattice filling component, ensuring no relative movement. This ensures that there are no dislocations during the movement of this embodiment, maintaining the integrity and continuity of the flapping wing surface. It also reduces friction on the flexible skin, improving its durability and service life. Therefore, to improve the similarity of the biomimetic flapping wing's shape and its propulsion efficiency, a flexible skin is applied to the outside of the three-dimensional non-uniform lattice filling component. The flexible skin completely encloses the filling component and the support frame, isolating the internal and external fluids of the biomimetic flapping wing. This prevents relative flow between the internal and external fluids, thus avoiding any impact on propulsion performance. Simultaneously, the flexible skin ensures the overall integrity of the flapping wing's movement.

[0070] In summary, the non-uniform three-dimensional lattice-filled flapping wing provided by this invention mainly consists of a biomimetic flapping wing integral support frame 1, a biomimetic flapping wing flexible skin 2, and a three-dimensional non-uniform three-dimensional lattice filler 3. Further, the biomimetic flapping wing integral support frame 1 comprises a primary torsion motor 11, a secondary flapping motor 12, a flexible elastic rib support frame 13, a central fin plate 14, a biomimetic flapping wing fixing bracket 15, a secondary flapping motor output shaft 16, and a central fin plate adapter fixing plate 17. Further, the flexible elastic rib support frame 13 comprises a primary chordal support rib 131, a secondary chordal support rib 132, a tertiary chordal support rib 133, a quaternary chordal support rib 134, a root support rib 135, an upper spanwise support rib 136, a lower spanwise support rib 137, and a tip support rib 138.

[0071] Combination Figures 2-6 The specific implementation process of this scheme is described as follows: The biomimetic flapping wing overall support frame 1 plays two roles in the implementation process: first, it provides power for the movement of the biomimetic flapping wing; second, it serves as the basic skeleton of the biomimetic flapping wing, providing a fixed foundation for the flexible skin 2 and the three-dimensional non-uniform lattice filling component 3. Regarding the power driving the biomimetic flapping wing, this embodiment uses a series drive structure composed of a primary torsion motor 11 and a secondary flapping motor 12. The primary torsion motor and the secondary flapping motor can rotate independently, and the power is output to the central fin plate 14 via the output shaft 16 of the secondary flapping motor. The central fin plate 14 and the output shaft 16 of the secondary flapping motor are connected by a central fin plate adapter fixing plate 17. The central fin plate fixing plate and the output shaft of the secondary flapping motor are connected by a key, and the central fin plate is connected to the central fin plate via a flange, ensuring no relative rotation between the central fin plate and the output shaft of the secondary flapping motor.

[0072] The present invention provides a manta ray-inspired underwater vehicle, comprising flapping wings filled with the aforementioned non-uniform three-dimensional lattice.

[0073] This invention proposes a biomimetic flapping wing shape-preserving scheme, which not only solves the problem of maintaining the shape of the flapping wing of the manta ray-inspired underwater vehicle under static and dynamic conditions, but also ensures the lightweight of the biomimetic flapping wing structure. This is of great significance for improving the propulsion and swimming performance of the manta ray-inspired underwater vehicle.

[0074] This invention describes preferred embodiments and their effects. However, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to include both the preferred embodiments and all changes and modifications falling within the scope of this invention.

[0075] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A flapping wing with non-uniform three-dimensional lattice filling, characterized in that, include: Bionic flapping wing integral support frame (1); Filler (3), which is filled within the integral support frame; A flexible skin (2) is wrapped around the surface of the overall support frame; The overall support frame (1) includes a central fin plate (14) and a flexible rib support frame (13). The central fin plate (14) is embedded in the flexible rib support frame (13), and there is a relative displacement between the central fin plate (14) and the flexible rib support frame (13); The flexible rib support frame (13) is made of a soft material; The filler (3) is a three-dimensional non-uniform lattice made of a flexible material; The lattice in the three-dimensional non-uniform solid lattice is non-uniformly distributed; The size of the lattice in the three-dimensional non-uniform solid lattice is arranged from large to small along the direction of the overall support frame (1); The outer contour surface of the filler (3) is higher than the boundary of the overall support frame. The filler (3) is in clearance fit with the flexible rib support frame (13) and is fixedly connected to the central fin plate (14). The flexible skin (2) is made of soft material by integral casting; the flexible skin (2) is bonded to the contour surface of the filler (3).

2. The flapping wing with non-uniform three-dimensional lattice filling according to claim 1, characterized in that, The three-dimensional non-uniform solid lattice is prepared according to the following steps: First, the three-dimensional lattice structure of the entire biomimetic flapping wing is designed and its distribution pattern is determined. The root and leading edge adopt a large lattice with thicker lattice edges and a larger lattice envelope volume. This lattice structure has greater rigidity. The thickness of the lattice edges and the envelope volume are gradually reduced along the trailing edge and wingtip of the flapping wing, that is, the rigidity is gradually reduced. Then, the three-dimensional design of the non-uniform three-dimensional lattice structure was completed in the three-dimensional drawing software. To facilitate processing, the non-uniform three-dimensional lattice structure inside the bionic flapping wing was divided into several parts, processed separately, and finally spliced ​​together. Finally, a three-dimensional lattice structure was fabricated using 3D printing additive manufacturing technology. Among them, 3D printing uses FDM, SLA or Polyjet technology, and the crystal structure adopts a regular hexahedral or regular tetrahedral crystal structure.

3. The flapping wing with non-uniform three-dimensional lattice filling according to claim 1, characterized in that, The flexible rib support frame (13) includes: The upper and lower strip support plates are set opposite to each other; A root support plate is provided between one end of the upper strip support plate and the lower strip support plate along their long sides, and a tip support plate is provided between the other ends; wherein, the distance between the upper strip support plate and the lower strip support plate at the root support plate is greater than the distance between them at the tip support plate. Between the upper strip support plate and the lower strip support plate, a plurality of elliptical support ribs are arranged sequentially from the root support plate to the tip support plate; wherein the circumference of the plurality of elliptical support ribs arranged sequentially from the root support plate to the tip support plate decreases sequentially. The major axis of each elliptical support rib is parallel to the upper or lower strip support plate; each elliptical support rib is rotatably connected to both the upper and lower strip support plates.

4. The flapping wing with non-uniform three-dimensional lattice filling according to claim 3, characterized in that, Each of the elliptical support ribs has a notch at both ends along its long axis; the notch allows the front and rear edges of the central fin plate (14) to be inserted, and leaves a gap for relative movement between the central fin plate (14) and each of the elliptical support ribs.

5. The flapping wing with non-uniform three-dimensional lattice filling according to claim 1, characterized in that, Also includes: Bionic flapping wing fixing bracket (15); A drive unit is mounted on the bionic flapping wing fixing bracket (15); The drive device is used to drive the central fin plate (14) to swing and drive the flexible rib support frame (13) to swing.

6. The flapping wing with non-uniform three-dimensional lattice filling according to claim 1, characterized in that, The central fin plate (14) adopts the skeletal form of the pectoral fin of a manta ray.

7. A manta ray-inspired underwater vehicle, characterized in that, The flapping wings include those with non-uniform three-dimensional lattice filling as described in any one of claims 1 to 6.

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