Blocking variable stiffness structure based on zigzag paper folding, tubular driver and planar driver

Abstract

The invention belongs to the technical field of soft robots, and discloses a blocking variable-stiffness structure based on zigzag paper folding, a tubular driver and a planar driver. Comprising a zigzag paper folding structure, an air bag and an air pipe, the zigzag paper folding structure is formed by folding paperboard in a Z shape and arranged in the air bag, the two ends of the zigzag paper folding structure are fixed to the air bag, and the air pipe is connected with an external air pressure control system. Quick switching between a blocking state and a non-blocking state is achieved by adjusting the air pressure in the air bag, and in the non-blocking state, the structure can be freely bent and stretched; in the blocked state, inter-layer friction increases to prevent stretching while maintaining flexural freedom. The problem of coupling of stretching rigidity and bending rigidity in a traditional blocking technology is solved, and the device has the advantages of being fast in response, high in rigidity adjustment ratio, simple in structure, light in weight and the like. A tubular or planar driver can be embedded into the structure, local rigidity adjustment is achieved through air pressure control, the structure is suitable for the precise movement and complex deformation requirements of the soft robot, and the environmental adaptability and task flexibility are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of soft robots, and particularly relates to a blocking variable stiffness structure, a tubular actuator, and a planar actuator based on zigzag origami. Background Art

[0002] The application of variable stiffness technology in soft robots endows them with environmental adaptability and task flexibility. Soft robots are usually made of highly flexible materials and can adapt to complex and irregular environments. However, this high flexibility also brings the problem of insufficient stiffness, which limits the load capacity and operation accuracy of the robots. By introducing variable stiffness technology, the robots can quickly switch between soft and rigid states, thus possessing both compliance and high load capacity at the same time. Common mechanical structure implementation methods include blocking (locking) mechanisms, that is, blocking the interlayer slip through a layered structure to change the overall stiffness. The advantage of the blocking method is that the structure is simple, easy to implement, has a rapid response, and can significantly improve the tensile stiffness, and is applicable to soft machine systems of different scales. However, the layer blocking technology also faces significant technical problems, the most important of which is the coupling problem of stiffness adjustment, that is, while increasing the tensile stiffness, it inevitably increases the bending stiffness. This coupling effect makes it difficult for soft robots to independently control the tensile and bending performances during the variable stiffness process, thus reducing the controllability and flexibility of the robot structure in complex tasks. In addition, uneven blocking often occurs in the blocking structure, resulting in unstable overall performance, further limiting the accuracy of robot movement. Summary of the Invention

[0003] The purpose of the present invention is to provide a blocking variable stiffness structure, a tubular actuator, and a planar actuator based on zigzag origami to solve the above technical problems.

[0004] To solve the above technical problems, the specific technical solutions of a blocking variable stiffness structure, a tubular actuator, and a planar actuator based on zigzag origami of the present invention are as follows: A blocking variable stiffness structure based on zigzag origami includes a zigzag origami structure, an airbag, and an air tube. The zigzag origami structure is formed by repeatedly folding ordinary cardboard in a Z shape after cutting. The zigzag origami structure is placed in the airbag and fixedly connected to the airbag at both ends. The air tube is fixedly connected to one end of the airbag and connected to an external air pressure control system for adjusting the internal air pressure of the airbag to achieve a rapid switch between blocking and non-blocking states. In the non-blocking state, the zigzag origami structure can be bent and stretched. In the blocking state, the zigzag origami structure cannot be stretched but can be freely bent.

[0005] Further, in the non-blocking state, the pressure in the airbag is 0; in the blocking state, the pressure in the airbag < 0.

[0006] Further, the zigzag origami structure is folded in a Z - shape to form a plurality of zigzag structures, and each zigzag structure partially overlaps, with a folding length of 10 mm.

[0007] Further, the thickness of the cardboard is 0.2 - 0.3 mm.

[0008] Further, both ends of the zigzag origami structure are fixed to the inner parts of both ends of the airbag with glue.

[0009] Further, the material of the airbag is silicone.

[0010] Further, the external dimensions of the airbag are designed according to the zigzag origami structure.

[0011] The present invention also discloses a tubular actuator, which includes the above - mentioned blocking variable - stiffness structure. The blocking variable - stiffness structure is embedded in the inner wall of the tubular soft actuator and is connected to a pneumatic control system through an air pipe. When under negative pressure, the tensile stiffness of the actuator increases, and the bending angle can be precisely controlled. When at zero pressure, the actuator restores its flexibility.

[0012] The present invention also discloses a planar actuator, which includes the above - mentioned blocking variable - stiffness structure. One or more blocking variable - stiffness structures are installed on the surface of the planar actuator. Through pneumatic control, local stiffness adjustment is realized to complete complex three - dimensional deformation.

[0013] A blocking variable - stiffness structure, a tubular actuator and a planar actuator based on zigzag origami of the present invention have the following advantages: Independent control of tensile and bending stiffness Through the cooperation of the zigzag origami structure and the airbag, the present invention only restricts the tensile stiffness in the blocked state while maintaining the bending freedom, solving the problem of the coupling of tensile and bending stiffness in traditional blocking technologies, and significantly improving the controllability and flexibility of soft robots in complex tasks.

[0014] Fast response and high stability The pneumatic control system is used to realize the switching between the blocked and unblocked states. The response time is short (as low as 0.1 s), and the origami structure is uniformly pressed by negative pressure, avoiding the uneven interlayer slip problem common in traditional blocking technologies and ensuring the stability of the overall performance.

[0015] Simple structure and easy to manufacture The zigzag origami structure is folded from ordinary cardboard, and the airbag is made of silicone. The material cost is low and the processing technology is simple, which is suitable for large - scale production and application.

[0016] High stiffness adjustment ratio In the blocked state, the tensile stiffness can be increased to 10 times the initial value, significantly enhancing the load - carrying capacity of the soft robot. At the same time, it restores flexibility under zero pressure and has strong adaptability.

[0017] Multifunctional Application Expansion This structure can be embedded in a tubular actuator or a planar actuator, and the local stiffness can be adjusted through partitioned pneumatic control, which is suitable for precise bending control (such as robotic arms) or complex three-dimensional deformation (such as bionic robots), expanding the application scenarios of soft robots.

[0018] Lightweight and Energy Saving The lightweight design of the origami structure and the airbag reduces the overall weight, and the stiffness can be adjusted only by switching the air pressure, with low energy consumption, making it suitable for long-term operations.

[0019] In summary, the present invention combines high performance, low cost and wide applicability, providing an innovative solution for the variable stiffness technology in the field of soft robots. Description of the Drawings

[0020] Figure 1 It is a three-dimensional structure schematic diagram of the blocking variable stiffness structure based on zigzag origami of the present invention; Figure 2 It is a planar structure schematic diagram of the blocking variable stiffness structure based on zigzag origami of the present invention; Figure 3 It is a schematic diagram of the tensile state and the bending state in the non-blocking state of the present invention; Figure 4 It is a schematic diagram of the bending state in the blocking state of the present invention; Figure 5 It is a schematic diagram of the tubular actuator structure of the present invention; Figure 6 It is a schematic diagram of the planar actuator structure of the present invention; Explanation of the marks in the figure: 1. Zigzag origami structure; 2. Airbag; 3. Air pipe. Detailed Embodiments

[0021] In order to better understand the purpose, structure and function of the present invention, the following further describes in detail a blocking variable stiffness structure, a tubular actuator and a planar actuator based on zigzag origami of the present invention with reference to the drawings.

[0022] As Figure 1 Figure 2As shown in the figure, a blocking variable stiffness structure based on zigzag origami of the present invention includes a zigzag origami structure 1, an airbag 2, and an air tube 3. The zigzag origami structure 1 is made by cutting ordinary cardboard and folding it repeatedly in a z-shape. The zigzag origami structure 1 is placed in the airbag 2 made of silicone and fixedly connected to the airbag 2 at both ends. The air tube 3 is fixedly connected to one end of the airbag 2 and connected to an external air pressure control system for adjusting the internal air pressure of the airbag 2 to achieve a rapid switch between the blocked and unblocked states. In the unblocked state (i.e., when the pressure is 0), the zigzag origami structure 1 is stretched along with the stretching of the airbag 2. The state after the zigzag origami structure 1 is unfolded is as shown in Figure 3 the figure. At this time, both bending and stretching of the zigzag origami structure 1 can be carried out freely. In the blocked state (i.e., when the pressure <0), the airbag 2 will closely adhere to the zigzag origami structure 1 and generate a pressing force on the zigzag origami structure 1. Under the action of the pressing force, a great deal of friction is generated between each layer of paper, thus preventing the interlayer slip of the zigzag origami structure 1 when subjected to a tensile force and making it impossible to be stretched. As shown in Figure 4 the figure, in the blocked state, when a bending moment is applied, the zigzag origami structure 1 undergoes flexible deformation, and the blocking structure can still bend freely.

[0023] Example 1: Fabrication and assembly of the zigzag origami structure 1 Material preparation: Select cardboard with a thickness of 0.2 - 0.3 mm and cut it into long strips according to the designed dimensions.

[0024] Folding process: Fold the cardboard in a Z-shape to form multiple zigzag structures, with each zigzag structure partially overlapping, and the folding length is 10 mm.

[0025] Fixing treatment: After folding, fix both ends with glue to ensure that the spacing between the zigzag structures is uniform.

[0026] Example 2: Fabrication and integration of the airbag 2 Mold design: Design a silicone airbag mold according to the outer dimensions of the zigzag origami structure 1, and reserve an air tube interface.

[0027] Airbag forming: Inject liquid silicone into the mold and form a flexible airbag after curing.

[0028] Assembly: Place the zigzag origami structure 1 into the airbag 2 and fix both ends by gluing to ensure that the zigzag origami structure 1 fits closely to the inner walls at both ends of the airbag 2.

[0029] Example 3: Application of the blocking variable stiffness structure Integration of the tubular actuator: As shown in Figure 5 the figure, embed the blocking variable stiffness structure of the present invention into the inner wall of the tubular soft actuator and connect it to the air pressure control system through the air tube 3.

[0030] Operation: When under negative pressure, the tensile stiffness of the actuator increases, and the bending angle can be precisely controlled; when under zero pressure, the actuator restores its flexibility.

[0031] Integration of planar actuators: As Figure 6 shown, one or more blocking variable stiffness structures of the present invention are installed on the surface of the planar actuator.

[0032] Operation: Through zonal air pressure control, local stiffness adjustment is achieved to complete complex three-dimensional deformation.

[0033] Example 4: Optimization of air pressure control parameters Blocking threshold: When the air pressure is lower than 0 kPa, the origami structure is completely blocked, and the tensile stiffness is increased to 10 times the initial value.

[0034] Response time: The air pressure switching can be completed within 0.1 second, which is suitable for dynamic task scenarios.

[0035] It can be understood that the present invention is described by some embodiments. Those skilled in the art know that without departing from the spirit and scope of the present invention, various changes or equivalent replacements can be made to these features and embodiments. Additionally, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. A blocking variable stiffness structure based on zigzag origami, characterized in that: It includes a zigzag origami structure (1), an airbag (2) and a trachea (3). The zigzag origami structure (1) is formed by repeatedly folding ordinary cardboard cut according to the Z shape. The zigzag origami structure (1) is placed in the airbag (2) and fixedly connected to both ends of the airbag (2). The trachea (3) is fixedly connected to one end of the airbag (2) and connected to an external air pressure control system for adjusting the internal air pressure of the airbag (2) to achieve a rapid switch between the blocked and unblocked states. In the unblocked state, the zigzag origami structure (1) can be bent and stretched. In the blocked state, the zigzag origami structure (1) cannot be stretched but can be freely bent.

2. The blocking variable stiffness structure based on zigzag origami according to claim 1, wherein In the unblocked state, the pressure in the airbag (2) is 0. In the blocked state, the pressure in the airbag (2) < 0.

3. The blocking variable stiffness structure based on zigzag origami according to claim 1, characterized in that, The zigzag origami structure (1) is folded in a Z shape to form a plurality of zigzag structures, and each zigzag structure partially overlaps, with a folding length of 10 mm.

4. The blocking variable stiffness structure based on zigzag origami according to claim 1, characterized in that: The thickness of the cardboard is 0.2 - 0.3 mm.

5. The blocking variable stiffness structure based on zigzag origami according to claim 1, characterized in that, Both ends of the zigzag origami structure (1) are internally fixed to both ends of the airbag (2) with glue.

6. The blocking variable stiffness structure based on zigzag origami according to claim 1, characterized in that The material of the airbag (2) is silica gel.

7. The blocking variable stiffness structure based on zigzag origami according to claim 1, wherein The external dimension of the airbag (2) is designed according to the zigzag origami structure (1).

8. A tubular driver, characterized in that, It includes the blocked variable stiffness structure according to any one of claims 1 - 7. The blocked variable stiffness structure is embedded in the inner wall of a tubular soft actuator and connected to an air pressure control system through a trachea (3). When under negative pressure, the tensile stiffness of the actuator increases, and the bending angle can be precisely controlled. When at zero pressure, the actuator restores flexibility.

9. A planar driver, characterized in that, It includes the blocked variable stiffness structure according to any one of claims 1 - 7. One or more blocked variable stiffness structures are installed on the surface of a planar actuator, and through air pressure control, local stiffness adjustment is achieved to complete complex three - dimensional deformation.

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