Deformable reticulated shell structure device with adjustable Gaussian curvature

Abstract

The invention discloses a deformable reticulated shell structure device with adjustable Gaussian curvature, the device comprises a reticulated shell structure, a driving mechanism and an executing mechanism, the reticulated shell structure is an initial plane configuration formed by hinging a plurality of flexible connecting rods in a plane, and the driving mechanism comprises a driving device and a connecting piece; the driving mechanism is connected with a central cross-shaped flexible connecting rod of the latticed shell structure through a connecting piece and is used for adjusting the included angle of the rhombic flexible connecting rod, controlling the overall radial length, triggering buckling of the latticed shell structure and realizing continuous deformation from a plane to a plane with positive Gaussian curvature or negative Gaussian curvature; the executing mechanism is arranged on the lower surface of the latticed shell structure and is of an array structure formed by arranging a plurality of flexible suction cups in the circumferential direction of an arc flexible connecting rod; and the base is used for fitting or contacting with a target surface after deformation is completed. The structure is simple in structure, easy to drive and controllable in deformation, and can meet the fitting requirement of a complex curved surface after being integrated with the flexible fitting layer or the adsorption structure.

Description

Technical Field

[0001] The present invention belongs to the field of robots, and relates to the fields of deformable structures, flexible structures, and profiling structures. Specifically, it relates to a deformable reticulated shell structure device with adjustable Gaussian curvature. Background Art

[0002] Currently, in applications such as flexible clamping, complex surface fitting, and soft body motion mechanisms, deformable structures need to achieve a controllable transformation from a compact configuration to a spatial surface to adapt to diverse target surfaces. Traditional methods mainly rely on shape memory alloys, pneumatic soft body drives, or complex multi-link mechanisms. Traditional nickel-titanium alloys are prone to fatigue failure under high-frequency loading. Although new alloys have some improvements, they still need further optimization. This means that in application scenarios that require frequent actions, the service life of shape memory alloys may be affected, and components need to be replaced more frequently, increasing the usage cost and maintenance workload. Pneumatic systems usually involve processes such as gas compression, transportation, and discharge. These processes are relatively slow, resulting in a slow response speed of pneumatic soft body drives and making it difficult to meet some application scenarios with high requirements for fast response, such as high-speed motion control or real-time feedback regulation. The transmission route of multi-link mechanisms is relatively long, and large energy losses will occur during the transmission process, resulting in reduced transmission efficiency. This not only increases energy consumption but may also affect the working performance and stability of the mechanism. In addition, due to the large number of links, complex multi-link mechanisms usually occupy a large space and may not be installable and usable in application scenarios with limited space, such as small mechanical equipment or inside robots.

[0003] In view of the above problems, there is an urgent need to propose a streamlined and continuously controllable transformation structure to solve the problems of complex control, structural redundancy, and limited adjustment range existing in existing deformable structures. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a deformable reticulated shell structure device with adjustable Gaussian curvature. By adjusting the included angle of the rhombic flexible links, the buckling deformation of the reticulated shell is controlled to achieve continuous and controllable transformation from a plane to a positive Gaussian curvature (spherical deformation) or a negative Gaussian curvature (saddle surface deformation).

[0005] A deformable reticulated shell structure device with adjustable Gaussian curvature, the device comprising: A reticulated shell structure, which is formed by connecting a plurality of flexible links through in-plane hinges to form an initial planar configuration. The reticulated shell structure includes outer circular arc flexible links, central cross flexible links, and straight flexible links connecting the two. The driving mechanism includes a driving device and a connecting member. The driving device is connected to the central cross flexible link of the reticulated shell structure through the connecting member, and is used to adjust the included angle of the diamond flexible links, control the overall radial length, trigger the buckling of the reticulated shell structure, and realize the continuous deformation from a plane to a surface with positive or negative Gaussian curvature; The actuating mechanism is arranged on the lower surface of the reticulated shell structure and is an array structure formed by arranging a plurality of flexible suction cups circumferentially along the arc flexible link; it is used to fit or contact the target surface after the deformation is completed.

[0006] Furthermore, the central cross flexible link is a cross structure fixedly connected in pairs or a link structure that can be independently adjusted, and is respectively connected to one or more driving devices for high-degree-of-freedom regional deformation control.

[0007] Furthermore, the in-plane hinge connection is that each link forms a hinge connection within the plane defined by the hinge rivets, and can rotate but cannot slide; its outer ring is composed of four arc flexible links, each of which is a quarter circle, and forms a closed outer ring through hinge rivets, and the four hinge points are located at both ends of the arc; Furthermore, each hinge point of the outer ring is hinged to the central cross flexible link through eight straight flexible links, and forms a single-group or multi-group diamond flexible link-shaped arrangement within the plane, or is other flexible or rigid mechanisms with the function of adjustable length, including telescopic arms, folding rods or parallel multi-rod mechanisms.

[0008] Furthermore, the outer ring link is in the form of a link with an arc segment, a straight segment, a broken line segment, an arbitrary continuously curved segmented configuration or an approximate configuration thereof.

[0009] Furthermore, the driving mechanism is realized by including at least one or a combination of a motor, a servo, a linear actuator, etc., and the connecting member is an integrally formed fixing frame or a split screw / catch structure for fixing the driving device on the reticulated shell structure.

[0010] Furthermore, the actuating mechanism includes an adsorption structure, a flexible fitting layer or a rigid contact component for performing the operation of fitting or contacting the target surface after the deformation is completed.

[0011] Specifically, the flexible links of the reticulated shell structure are made of materials including but not limited to high-elastic polymers, composite materials or metal alloys, and some links break the plane symmetry by adjusting the thickness, material stiffness or local connection method to guide the deformation direction.

[0012] Specifically, the suction cup is made of rubber material, and realizes the adsorption function through a negative pressure system, and is suitable for grasping spherical or saddle-shaped workpieces.

[0013] Specifically, the articulated rivet is made of brass material and is not fully riveted to achieve the articulated rotation between the connecting rods and limit the slippage.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. Simple structure: Clear configuration, light weight, easy to manufacture, and suitable for modular assembly; 2. Curvature controllable: Support continuous transition from plane to positive and negative Gaussian curvatures, with a wide deformation range; 3. Simple drive: Complex profiling behavior can be achieved through single-axis drive; 4. Wide application: After integrating the actuator, it is applicable to various scenarios such as profiling grippers, pipeline crawling feet, deformable platforms, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below in conjunction with the drawings and embodiments: Figure 1 It is a schematic diagram of the overall structure of the deformable structure of the present invention; Figure 2 It is a schematic diagram of the reticulated shell structure of the present invention (the connection part has been omitted); Figure 3 It is a deformation schematic diagram of the reticulated shell structure of the present invention (the articulated rivets have been omitted); Figure 4 It is a schematic diagram of the drive-reticulated shell connection part of the present invention (the bolts and nuts have been omitted); Figure 5 It is a schematic diagram of the deformable structure of the present invention with an attached actuator (suction cup array) and its deformation schematic diagram (parts such as the drive, suction cup air circuit, and articulated rivets have been omitted); Reference numerals: 1 - servo motor; 2 - arc flexible connecting rod; 3 - articulated rivet; 4 - central cross flexible connecting rod; 5 - linear flexible connecting rod; 6 - suction cup; 7 - servo motor fixing seat; 8 - diamond flexible connecting rod; 9 - included angle of diamond flexible connecting rod. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] As Figures 1-4 shown, this embodiment provides a deformable reticulated shell structure with adjustable Gaussian curvature, including a reticulated shell structure, a drive mechanism, and an actuator.

[0017] Latticed shell structure: An initial planar configuration is formed by four arc-shaped flexible connecting rods 2, eight straight-line flexible connecting rods 5, and two central cross-shaped flexible connecting rods 4 through in-plane articulated rivets 3. Each connecting rod forms a hinge connection within the plane defined by the articulated rivets 3, capable of rotating but not sliding. The outer ring is composed of four arc-shaped flexible connecting rods 2, each being a quarter circle with a radius of 40 mm. They are articulated through articulated rivets 3 to form a closed outer ring, and the articulation points are located at both ends of the arc (a total of 4 articulation points). Each articulation point is articulated with the central cross-shaped flexible connecting rod 4 through eight straight-line flexible connecting rods 5, forming a cross-shaped layout composed of four groups of diamond-shaped flexible connecting rods 8 as shown in Figure 2 the figure.

[0018] In this embodiment, to enhance the deformation ability, all flexible connecting rods (i.e., arc-shaped flexible connecting rods 2, central cross-shaped flexible connecting rods 4, and straight-line flexible connecting rods 5) are made of polylactic acid (PLA, Young's modulus is about 3 GPa), and their shapes are all sheet structures with a cross-sectional width greater than the height. The cross-sectional shape is rectangular (width 6.5 mm, height 0.5 mm). However, this design does not limit the specific material, nor the cross-sectional ratio and shape, and can also be adjusted according to the actual space layout and load requirements. In addition, the connecting rods in this embodiment are not limited to straight lines and arcs, and can also be in the form of broken lines, any continuously curved segmented configurations, or approximate configurations of connecting rods, which are used to adapt to different configuration and deformation path requirements, and can still achieve continuous conversion from a plane to a space curved surface. The diameter of the articulated rivet 3 is 2 mm, made of brass material, and is not fully riveted to achieve articulated rotation between the connecting rods and limit sliding.

[0019] In the radial direction of this embodiment, a single group of diamond-shaped flexible connecting rods 8 is arranged to achieve simple structure and rapid response deformation control. In other implementations, it can also be replaced by multiple groups of diamond-shaped flexible connecting rod arrangements, or other adjustable-scale composite structures to meet the application requirements of different complexities and control precisions.

[0020] Drive mechanism: The drive mechanism is realized by using at least one or a combination of motors, servo motors 1, and linear drivers. The connecting piece is a structure of an integrally formed fixing frame or a split screw / buckle, which is used to fix the driving device to the latticed shell structure. Specifically as follows: One servo motor 1 (model: MG90S, torque 2.0 kg / cm) is used to directly control the included angle 9 of the diamond-shaped flexible connecting rod, so that the internal radial dimension of the latticed shell structure changes, realizing continuous deformation control.

[0021] This embodiment uses a servo motor 1 to drive. The servo motor 1 provides torque to drive the central cross-shaped flexible connecting rod 4 to rotate, so that the included angle 9 of the diamond-shaped flexible connecting rod changes. The drive mechanism described in this embodiment uses as shown in Figure 4The integrally formed servo fixing base 7 shown, made of polylactic acid with a thickness of 3 mm, is used to connect one of the central cross flexible linkages 4. In practical applications, the servo fixing base 7 can also adopt a split design and be connected through structures such as screws or snaps. The rocker arm of the servo 1 is fixed to the other central cross flexible linkage 4 by two M2 screws. When the servo 1 rotates, a relative rotation angle is generated between its rocker arm and the servo 1 body, thereby causing changes in the angles 9 of the four groups of rhombic flexible linkages.

[0022] In this embodiment, the central cross flexible linkage 4 adopts a cross linkage structure that is fixedly connected to each other and driven by a single servo 1, which is convenient for simplifying control and installation. However, in other implementation schemes, the central cross flexible linkage 4 can also be divided into independent units and connected to two independent drivers respectively to achieve regional deformation control with higher degrees of freedom.

[0023] Deformation process: Each group of rhombic flexible linkage angle 9 corresponds to the radial length in its corresponding direction, thereby adjusting the curvature state of the overall linkage. By driving the central cross flexible linkage 4 to rotate bidirectionally by the servo 1, the rhombic flexible linkage angle 9 is changed, causing the radial lengths in all directions to expand and contract, and controlling the overall curvature state of the reticulated shell (as Figure 3 shown). The specific deformation process is as follows: In the initial state, the reticulated shell is in the planar configuration as shown in Figure 1 , the rhombic flexible linkage angle 9 is about 45°, the dimension of each group of rhombic flexible linkages in the radial direction is about 40 mm, and the overall dimension of the reticulated shell structure is about 85 mm × 85 mm; Positive Gaussian curvature deformation: When the rhombic flexible linkage angle 9 decreases to α (α = 20°), its corresponding radial length increases to about 90 mm, and the reticulated shell generates positive Gaussian curvature deformation, forming the spherical configuration shown in the upper half of Figure 5 (the minimum radius of curvature is about 60 mm); Negative Gaussian curvature deformation: When the rhombic flexible linkage angle 9 increases to about β (β = 70°), its corresponding radial length decreases to about 70 mm, and the reticulated shell generates negative Gaussian curvature deformation, forming the saddle surface configuration shown in the lower half of Figure 5 .

[0024] Arbitrary angle regulation: By precisely controlling the rotation angle of the servo 1, the rhombic angle 9 can be continuously adjusted within the range of 20° to 70°, and the radial length and curvature state of the reticulated shell can stay in any intermediate state, realizing continuous deformation regulation from the planar configuration to positive Gaussian curvature (spherical surface) or negative Gaussian curvature (saddle surface).

[0025] In the case of ideal symmetry, the reticulated shell may buckle in any direction after being stressed. To achieve the uniqueness and controllability of the deformation direction, the structural properties of some connecting rods (section shape, material stiffness, pre-bending angle, etc.) or the local connection method can be changed to break the plane symmetry and guide the structure to deform in a specified direction.

[0026] Actuator: In this embodiment, an actuator is further provided for functional interaction with the target surface after deformation. The actuator is arranged on the lower surface of the reticulated shell and is an array structure formed by 8 flexible suction cups 6 (diameter 12 mm) arranged circumferentially along the arc-shaped flexible connecting rod 2. The suction cup 6 is made of rubber material and realizes the adsorption function through a negative pressure system, which is suitable for grasping spherical or saddle-shaped workpieces.

[0027] In specific applications such as pipeline crawling, flexible clamping, and closed sealing, the actuator can be in the form of an adsorption structure, a flexible fitting layer, or a rigid contact component to achieve grasping or support, meeting the stable fitting requirements under different working conditions.

[0028] Furthermore, the structure supports connection with other structures through hinge, snap or magnetic attraction methods to form a large-scale deformable structure, which is suitable for complex curved surface fitting or multi-legged robot applications.

[0029] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A deformable reticulated shell structure device with adjustable Gaussian curvature, characterized in that, The device includes: A reticulated shell structure, which is composed of several flexible linkages hinged in a plane to form an initial planar configuration. The reticulated shell structure includes outer ring linkages, a central cross-shaped flexible linkage, and linear flexible linkages connecting the two; A driving mechanism, including a driving device and a connecting member. The driving device is connected to the central cross-shaped flexible linkage of the reticulated shell structure through the connecting member, and is used to adjust the included angle of the diamond-shaped flexible linkages, control the overall radial length, cause the reticulated shell structure to buckle, and realize continuous deformation from a plane to a surface with positive or negative Gaussian curvature; An actuating mechanism, which is arranged on the lower surface of the reticulated shell structure and is an array structure formed by arranging several flexible suction cups circumferentially along the arc-shaped flexible linkages; it is used to fit or contact the target surface after the deformation is completed.

2. The deformable reticulated shell structure device with adjustable Gaussian curvature according to claim 1, characterized in that The central cross-shaped flexible linkage is a cross structure fixedly connected in pairs, or a linkage structure that can be independently adjusted, and is respectively connected to one or more driving devices for high-degree-of-freedom regional deformation control.

3. The deformable reticulated shell structure device with adjustable Gaussian curvature according to claim 1, characterized in that, The in-plane hinge is that each linkage forms a hinge connection within the plane defined by the hinge rivets, and can rotate but not slip; its outer ring is composed of four arc-shaped flexible linkages, each of which is a quarter circle, and is hinged by hinge rivets to form a closed outer ring, and the four hinge points are located at both ends of the arc.

4. The device of a deformable reticulated shell structure with adjustable Gaussian curvature according to claim 3, characterized in that Each hinge point of the outer ring is hinged to the central cross-shaped flexible linkage through eight linear flexible linkages, forming a single-group or multi-group diamond-shaped flexible linkage arrangement in the plane, or other flexible or rigid mechanisms with the function of adjustable length, including telescopic arms, folding rods, or parallel multi-link mechanisms.

5. The deformable reticulated shell structure device with adjustable Gaussian curvature according to claim 1, characterized in that, The outer ring linkages are in the form of arc segments, straight line segments, broken line segments, any continuous curvature segmented configuration, or their approximate configurations.

6. The device of the deformable reticulated shell structure with adjustable Gaussian curvature according to claim 1, characterized in that The driving mechanism is realized by using at least one or a combination of motors, servos, and linear drivers. The connecting member is an integrally formed fixing bracket or a split screw / snap structure for fixing the driving device on the reticulated shell structure.

7. The deformable reticulated shell structure device with adjustable Gaussian curvature according to claim 1, characterized in that The actuating mechanism includes an adsorption structure, a flexible fitting layer, or a rigid contact component, which is used to perform the operation of fitting or contacting the target surface after the deformation is completed.

8. The deformable reticulated shell structure device with adjustable Gaussian curvature according to claim 1, characterized in that The flexible linkages of the reticulated shell structure are made of materials including but not limited to high-elastic polymers, composite materials, or metal alloys. Some linkages break the plane symmetry by adjusting the thickness, material stiffness, or local connection method to guide the deformation direction.

9. The deformable reticulated shell structure device with adjustable Gaussian curvature according to claim 1, characterized in that, The suction cups are made of rubber materials and realize the adsorption function through a negative pressure system, and are adapted to grasp spherical or saddle-shaped workpieces.

10. The device of a deformable reticulated shell structure with adjustable Gaussian curvature according to claim 1, characterized in that, The hinge rivets are made of brass materials and are not fully riveted to realize the hinge rotation between the linkages and limit the slip.

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