A deformable lattice shell structure device with adjustable Gaussian curvature

Abstract

The present invention discloses a deformable lattice shell structure device with adjustable Gaussian curvature, which includes a lattice shell structure, a driving mechanism and an actuator. The lattice shell structure is formed by a plurality of flexible links hinged in a plane to form an initial planar configuration. The driving mechanism includes a driving device and a connecting piece. The driving mechanism is connected to the central cross flexible link of the lattice shell structure through the connecting piece, and is used to adjust the angle of the diamond-shaped flexible link, control the overall radial length, induce the buckling of the lattice shell structure, and realize continuous deformation from a plane to one with positive Gaussian curvature or negative Gaussian curvature; the actuator is arranged on the lower surface of the lattice shell structure, and is an array structure formed by a plurality of flexible suction cups arranged circumferentially along the arc flexible link; and is used to fit or contact the target surface after the deformation is completed. The structure has a simple structure, simple drive, and controllable deformation. After integrating a flexible bonding layer or adsorption structure, it can adapt to the needs of fitting complex curved surfaces.

Description

Technical Field

[0001] The present invention belongs to the field of robotics, and relates to the fields of deformable structures, flexible structures, and contour-profiling structures, and in particular to a deformable lattice shell structure device with adjustable Gaussian curvature. Background Art

[0002] Nowadays, in applications such as flexible clamping, complex surface fitting, and soft motion mechanisms, deformable structures need to achieve controllable transformation from compact configurations to spatial surfaces to adapt to diverse target surfaces. Traditional methods mainly rely on shape memory alloys, pneumatic soft drives, or complex multi-link mechanisms. Traditional nickel-titanium alloys are prone to fatigue failure under high-frequency loading. Although new alloys have improved, they still need further optimization. This means that in application scenarios that require frequent movements, the service life of shape memory alloys may be affected, requiring more frequent replacement of parts, increasing usage costs and maintenance workload; pneumatic systems usually involve gas compression, delivery, and discharge processes, which are relatively slow, resulting in insufficient response speed for pneumatic soft drives, making it difficult to meet some application scenarios with high requirements for fast response, such as high-speed motion control or real-time feedback adjustment. The transmission route of the multi-link mechanism is relatively long, which will generate large energy losses 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. For application scenarios with limited space, such as small mechanical equipment or inside robots, they may not be installed and used.

[0003] In response to 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 in existing deformable structures. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a deformable lattice shell structure device with adjustable Gaussian curvature. By adjusting the angle of the diamond-shaped flexible connecting rods, the buckling deformation of the lattice shell is controlled to achieve continuous and controllable transformation from a plane to positive Gaussian curvature (spherical deformation) or negative Gaussian curvature (saddle surface deformation).

[0005] A deformable lattice shell structure device with adjustable Gaussian curvature, comprising:

[0006] A lattice shell structure, wherein a plurality of flexible links are hinged in a plane to form an initial plane configuration, the lattice shell structure includes an outer circular arc flexible link, a central cross flexible link, and a straight flexible link connecting the two;

[0007] A driving mechanism includes a driving device and a connecting member. The driving device is connected to the central cross flexible link of the lattice shell structure through the connecting member, and is used to adjust the angle of the diamond-shaped flexible link to control the overall radial length, thereby inducing the buckling of the lattice shell structure and achieving continuous deformation from a flat surface to a positive Gaussian curvature or a negative Gaussian curvature.

[0008] The actuator is arranged on the lower surface of the lattice shell structure and is an array structure composed of a number of flexible suction cups arranged circumferentially along a circular arc flexible connecting rod; it is used to fit or contact the target surface after the deformation is completed.

[0009] Furthermore, the central cross flexible link is a cross structure in which two links are fixedly connected, or a link structure that can be adjusted independently, which is respectively connected to one or more driving devices for high-degree-of-freedom regional deformation control.

[0010] Furthermore, the in-plane hinge is that each connecting rod forms a hinge link within the plane defined by the hinge rivet, which can rotate but cannot slide; its outer ring is composed of four arc-shaped flexible connecting rods, each segment is a quarter circle, and is hinged by the hinge rivet to form a closed outer ring, with four hinge points located at the two ends of the arc;

[0011] Furthermore, each hinge point of the outer ring is hinged to the central cross flexible link through eight straight flexible links, forming a single or multiple groups of diamond-shaped flexible links in the plane, or other flexible or rigid mechanisms with adjustable length function, including retractable arms, folding rods or parallel multi-rod mechanisms.

[0012] Furthermore, the outer ring connecting rod is in the form of a connecting rod with an arc segment, a straight line segment, a broken line segment, any continuous curvature segmented configuration or an approximate configuration thereof.

[0013] Furthermore, the driving mechanism includes at least one or more combinations of a motor, a servo, and a linear drive, and the connecting piece is an integrally formed fixing frame or a split screw / snap structure for fixing the driving device to the lattice shell structure.

[0014] Furthermore, the actuator includes an adsorption structure, a flexible conforming layer or a rigid contact component, which is used to conform to or contact the target surface after the deformation is completed.

[0015] Specifically, the flexible connecting rods of the lattice shell structure are made of materials including but not limited to highly elastic polymers, composite materials or metal alloys, and some connecting rods break the plane symmetry by adjusting the thickness, material stiffness or local connection mode to guide the deformation direction.

[0016] 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-surface workpieces.

[0017] Specifically, the hinge rivets are made of brass material and are not completely riveted, so as to achieve hinged rotation between the connecting rods and limit slippage.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. Simple structure: clear configuration, light weight, easy to manufacture, suitable for modular assembly;

[0020] 2. Controllable curvature: supports continuous transition from flat to positive and negative Gaussian curvature, with a wide range of deformation;

[0021] 3. Simple drive: complex profiling behavior can be achieved through single-axis drive;

[0022] 4. Wide application: After integrating the actuator, it is suitable for various scenarios such as contoured grippers, pipeline crawling feet, and deformable platforms. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0024] Figure 1 Schematic diagram of the overall structure of the deformable structure of the present invention;

[0025] Figure 2 Schematic diagram of the structure of the lattice shell structure of the present invention (the connection part is omitted);

[0026] Figure 3 Schematic diagram of deformation of the lattice shell structure of the present invention (hinged rivets are omitted);

[0027] Figure 4 Schematic diagram of the drive-lattice shell connection portion of the present invention (bolts and nuts are omitted);

[0028] Figure 5 Schematic diagram of the deformable structure of the present invention with an attached execution structure (suction cup array) and its deformation diagram (the drive, suction cup air circuit, hinged rivets, etc. are omitted);

[0029] Figure numerals: 1-servo; 2-arc flexible link; 3-hinged rivet; 4-central cross flexible link; 5-straight flexible link; 6-suction cup; 7-servo fixing seat; 8-diamond flexible link; 9-diamond flexible link angle. DETAILED DESCRIPTION

[0030] like Figures 1-4 As shown, this embodiment provides a deformable lattice shell structure with adjustable Gaussian curvature, including a lattice shell structure, a driving mechanism and an actuator.

[0031] Grid shell structure: The initial plane configuration is formed by four segments of circular arc flexible links 2, eight segments of straight line flexible links 5 and two pairs of central cross flexible links 4 through in-plane hinged rivets 3. Each link forms a hinge link in the plane defined by the hinged rivet 3, which can rotate but cannot slide. The outer ring is composed of four segments of circular arc flexible links 2, each segment is a quarter circle with a radius of 40mm, and is hinged by hinged rivets 3 to form a closed outer ring. The hinge points are located at both ends of the arc (a total of 4 hinge points). Each hinge point is hinged to the central cross flexible link 4 through eight segments of straight line flexible links 5, forming the following in the plane. Figure 2 The four groups of diamond-shaped flexible links 8 shown are arranged in a cross shape.

[0032] In this embodiment, in order to enhance the deformation capacity, all flexible links (i.e., the arc flexible link 2, the central cross flexible link 4, and the straight flexible link 5) are made of polylactic acid (PLA, Young's modulus of about 3 GPa), and are shaped like a sheet with a cross-sectional width greater than the height, with a rectangular cross-sectional shape (6.5 mm wide, 0.5 mm high). However, this design does not limit the specific material, nor does it limit the cross-sectional proportions and shapes, 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 arc shapes, but can also be in the form of broken line segments, any continuous curvature segmented configuration, or its approximate configuration, to adapt to different configurations and deformation path requirements, and can still achieve continuous conversion from plane to spatial curved surface deformation. The diameter of the hinged rivet 3 is 2 mm, and it is made of brass. It is not fully riveted to achieve hinged rotation between the connecting rods and limit slippage.

[0033] In this embodiment, a single set of diamond-shaped flexible links 8 is arranged in the radial direction to achieve a simple structure and rapid response to deformation control. In other implementations, it can also be replaced with multiple sets of diamond-shaped flexible links, or other composite structures with adjustable scales to meet application requirements of different complexity and control accuracy.

[0034] Drive mechanism: The drive mechanism is realized by using at least one or more combinations of a motor, a servo 1, and a linear actuator. The connecting piece is an integrated fixing frame or a split screw / clip structure, which is used to fix the drive device to the lattice shell structure. The details are as follows:

[0035] A steering gear 1 (model: MG90S, torque 2.0 kg / cm) is used to directly control the angle 9 of the diamond-shaped flexible link, so that the radial dimension inside the lattice shell structure changes, realizing continuous deformation control.

[0036] This embodiment is driven by a steering gear 1, which provides torque to drive the central cross flexible link 4 to rotate, so that the diamond flexible link angle 9 changes. Figure 4The illustrated, one-piece servo mounting bracket 7, made of polylactic acid and 3 mm thick, is used to connect one of the central cross-shaped flexible links 4. In practice, the servo mounting bracket 7 can also be a split design, connected via screws or snaps. The servo's rocker arm is secured to the other central cross-shaped flexible link 4 via two M2 screws. As the servo rotates, the rocker arm rotates relative to the servo's main body, causing the included angle 9 of the four diamond-shaped flexible links to change.

[0037] In this embodiment, the central cross-shaped flexible links 4 are interconnected and driven by a single servo 1, simplifying control and installation. However, in other implementations, the central cross-shaped flexible links 4 can be separated into independent units, each connected to two independent actuators, to achieve higher degrees of freedom in regionalized deformation control.

[0038] Deformation process: The angle 9 of each set of diamond-shaped flexible links corresponds to the radial length in the direction in which it is located, thereby adjusting the curvature state of the entire link. The steering gear 1 drives the central cross flexible link 4 to rotate in both directions, so that the angle 9 of the diamond-shaped flexible link changes, causing the radial length in each direction to expand and contract, and controlling the overall curvature state of the lattice shell (such as Figure 3 The specific deformation process is as follows:

[0039] The initial state of the lattice shell is as follows Figure 1 In the plane configuration shown, the included angle of the diamond-shaped flexible link is about 45°, the radial dimension of each set of diamond-shaped flexible links is about 40 mm, and the overall lattice shell structure size is about 85 mm × 85 mm;

[0040] Positive Gaussian curvature deformation: When the rhombus flexible link angle 9 is reduced to α (α = 20°), the corresponding radial length increases to about 90mm, and the lattice shell produces positive Gaussian curvature deformation, forming Figure 5 The spherical configuration shown in the upper part (the minimum radius of curvature is about 60 mm);

[0041] Negative Gaussian curvature deformation: When the rhombus flexible link angle 9 increases to about β (β = 70°), its corresponding radial length decreases to about 70mm, and the lattice shell produces negative Gaussian curvature deformation, forming Figure 5 The saddle configuration is shown in the lower half.

[0042] Arbitrary angle control: By precisely controlling the rotation angle of the servo 1, the diamond angle 9 can be continuously adjusted within the range of 20° to 70°. The radial length and curvature state of the lattice shell can remain in any intermediate state, realizing continuous deformation control from a plane configuration to positive Gaussian curvature (spherical surface) or negative Gaussian curvature (saddle surface).

[0043] Under ideal symmetry, a lattice shell can buckle in any direction when subjected to stress. To achieve unique and controllable deformation direction, the structural properties of some connecting rods (cross-sectional shape, material stiffness, pre-bend angle, etc.) or local connection methods can be modified to break the plane symmetry and guide the structure to deform in a specific direction.

[0044] Actuator: This embodiment further incorporates an actuator for functional interaction with the target surface after deformation. The actuator is located on the lower surface of the lattice shell and comprises an array of eight flexible suction cups 6 (12 mm diameter) arranged circumferentially along the arc-shaped flexible connecting rod 2. The suction cups 6 are made of rubber and utilize a negative pressure system to achieve suction, making them suitable for gripping workpieces with spherical or saddle-shaped surfaces.

[0045] 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 bonding layer, or a rigid contact component to achieve gripping or support, meeting the stable bonding requirements under different working conditions.

[0046] Furthermore, the structure supports connection with other structures through hinges, snaps or magnets to form a large-scale deformable structure, which is suitable for complex surface fitting or multi-legged robot applications.

[0047] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A deformable lattice shell structure device with adjustable Gaussian curvature, characterized in that: The device includes: A lattice shell structure, wherein a plurality of flexible links are hinged in a plane to form an initial planar configuration, the lattice shell structure includes an outer ring link, a central cross flexible link, and a linear flexible link connecting the two; A driving mechanism includes a driving device and a connecting member. The driving device is connected to the central cross flexible link of the lattice shell structure through the connecting member, and is used to adjust the angle of the diamond-shaped flexible link to control the overall radial length, thereby inducing the buckling of the lattice shell structure and achieving continuous deformation from a flat surface to a positive Gaussian curvature or a negative Gaussian curvature. The actuator is arranged on the lower surface of the lattice shell structure and is an array structure composed of a number of flexible suction cups arranged circumferentially along a circular arc flexible connecting rod; it is used to fit or contact the target surface after the deformation is completed.

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

3. The deformable lattice shell structure device with adjustable Gaussian curvature according to claim 1, characterized in that: The in-plane hinge is that each connecting rod forms a hinge link within the plane defined by the hinge rivet, which can rotate but cannot slide; its outer ring is composed of four arc flexible connecting rods, each segment 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 deformable lattice shell structure device with adjustable Gaussian curvature according to claim 3, characterized in that: Each hinge point of the outer ring is hinged to the central cross flexible link through eight straight flexible links, forming a single group or multiple groups of diamond-shaped flexible links in a plane.

5. The deformable lattice shell structure device with adjustable Gaussian curvature according to claim 1, characterized in that: The connecting piece is an integrally formed fixing frame or a split screw / clip structure, which is used to fix the driving device on the lattice shell structure.

6. The Gaussian curvature controllable deformable lattice shell structure device according to claim 1, characterized in that: The flexible connecting rods of the lattice shell structure are made of materials including but not limited to highly elastic polymers and metal alloys. Some connecting rods break the plane symmetry by adjusting the thickness, material stiffness or local connection mode to guide the deformation direction.

7. The deformable lattice shell structure device with adjustable Gaussian curvature according to claim 1, characterized in that: The suction cup is made of rubber material and realizes adsorption function through a negative pressure system, and is suitable for grasping spherical or saddle surface workpieces.

8. The deformable lattice shell structure device with adjustable Gaussian curvature according to claim 3, characterized in that: The hinge rivets are made of brass and are not completely riveted, so as to realize hinge rotation between the connecting rods and limit slippage.

Images