A multimodal pneumatic space exploration robotic arm based on the tristable properties of Kresling origami.

Abstract

This invention discloses a multimodal aerodynamic space exploration robotic arm based on the tristable characteristics of Kresling origami. The robotic arm includes origami units, each containing an airbag. By using Kresling origami as the unit structure, this invention ensures the robotic arm's lightweight design while reducing the interaction forces between the robotic arm and the target object during exploration, thus improving structural reliability and effectively adapting to the special environment of microgravity in space. The origami structure of this invention achieves a third stable state with high stiffness and stability on specific surfaces through the expansion of the airbag inside the unit. This breaks the original deformation mode of Kresling origami, increases bending motion, and allows for programmable control of the airbag's state, enabling the robotic arm to achieve full-circumference bending and diverse motion modes. This effectively improves the ability of continuous robotic arms to perform complex tasks and promotes the development of origami structures in the field of soft robotic space exploration technology.

Description

Technical Field

[0001] This invention relates to a pneumatic space exploration robotic arm, specifically a multimodal pneumatic space exploration robotic arm based on the Kresling origami tristable characteristics, belonging to the field of soft robot space exploration technology. Background Technology

[0002] With the rapid development of science and technology, human exploration of space is increasing. Compared to the methods of extravehicular operation and maintenance by astronauts, space exploration robots are safer and more flexible. Efficient and stable exploration robots are crucial for space activities such as lunar / planetary exploration. Benefiting from the large-scale and mature industrial application of rigid joint-connected robotic arms, traditional space exploration robots mostly use single or multiple traditional robotic arms with rigid joints for operation. However, their rigid connection structure often leads to unnecessary collisions, causing damage to the target object. Furthermore, rigid robotic arms composed of discrete joints have very limited degrees of freedom. Their limitations in dexterity, flexibility, and obstacle avoidance also make it difficult for such rigid machines to meet the requirements of complex tasks. In addition, rigid robotic arms often use end effectors for grasping. Typically, when traditional space exploration robotic arms are applied to target objects with unknown shapes and structural dimensions, the operation process is complex and unreliable. All these drawbacks have prompted us to consider the idea of ​​applying continuum robotic arms to space exploration.

[0003] Origami structures, due to their unfoldable and adjustable folding capabilities, possess mechanical properties that are difficult to achieve with traditional materials. They can change their shape and size in response to external stimuli, achieving various forms of movement. In recent years, they have been widely used in various fields, including deformable structures, origami robots, and biomedical devices. Therefore, this invention focuses on origami robotic arms to explore their feasibility in space exploration and space sampling. Although existing continuous robotic arms have good compliance and human-computer interaction capabilities, they usually rely on multiple complex drive components, which greatly hinders the flexibility of robotic arm operation. The movement of robotic arms is still limited by finite degrees of freedom, such as contraction / extension and unidirectional or bidirectional bending. For the working requirements of some complex environments, robotic arms still need to achieve richer types of movement and lightweight structural components. To date, origami robotic arms have rarely been used in space exploration research, especially in the fields of space sampling or even asteroid sampling, leaving a significant gap. Summary of the Invention

[0004] The purpose of this invention is to provide a multimodal pneumatic space exploration robotic arm based on the Kresling origami tristable characteristics in order to solve at least one of the above-mentioned technical problems.

[0005] The present invention achieves the above objectives through the following technical solution: a multimodal pneumatic space exploration robotic arm based on the Kresling origami tristable characteristics, comprising a robotic arm, the robotic arm comprising several origami units, and an airbag disposed within each origami unit;

[0006] The origami unit is composed of two layers of Kresling origami tubes with the same or opposite chirality and square paper strips spliced ​​together. The square paper strips are connected between the Kresling origami tubes. The origami unit has a cavity inside. The Kresling origami tube has three steady states under the driving force of the cavity and the selective expansion of the air bladder. Furthermore, some inner unit surfaces of the origami unit form special facets by reducing the area of ​​two symmetrical triangles. The air bladder is located on the special facets inside the origami unit and is connected to an external air source.

[0007] As a further embodiment of the present invention: the robotic arm also includes an end effector and an end effector. The end effector is located at the end of the robotic arm and has multiple slots for interference fit with the end venting component. The end effector has multiple protruding cuboids for interference fit with the slots of the end effector and is installed at the bottom of the lower folding unit. The end effector has two through holes.

[0008] As a further embodiment of the present invention: the robotic arm also includes an intermediate end support and an intermediate end air inlet. The intermediate end support is located at the upper and lower ends of adjacent folding units, and the intermediate end support is interference-fitted with the square paper strip. The intermediate end support is provided with four protruding cuboids and has a circular through hole. The intermediate end air inlet is located between two adjacent folding units and has an external thread and four rectangular slots.

[0009] As a further embodiment of the present invention: the robotic arm also includes an intermediate end connector and a top end connector. The intermediate end connector is located between adjacent folding units and has four rectangular slots. The intermediate end connector also has an internal threaded hole at its center. The top end connector is located at the top of the robotic arm and has four rectangular slots.

[0010] As a further aspect of the invention: the Kresling origami tube is composed of multiple arrays of spatial polygons. The characteristic parameters of each polygon include the number of sides (n), the side lengths of the upper and lower polygons (AB / CD), and two angles (α and β). Each cell constituting the spatial polygon array is formed by splicing two triangles, thus creating two mountain creases (AD / BC) and one valley crease (AC). During the folding process, it exhibits a coupled motion of compression and torsion. The crease length is expressed as:

[0011] L AB =s

[0012]

[0013]

[0014] The circumradius of the upper and lower polygons can be expressed as:

[0015]

[0016] Furthermore, for the first and second steady states, the height h and axial rotation angles (α and β) are used to describe them, specifically including:

[0017] In the parameter selection of the origami unit (1), the rotation angles (α and β) are determined; the projection of point D onto the lower polygon coincides with point B, therefore ∠AOB=γ, BD=OOˊ=h, and the length of h is obtained through △ABD and △ABO:

[0018]

[0019] The structural parameters of the Kresling origami tube include four constants (n, s, α, β) and three variables (γ, h, d). When h is at its maximum value, the Kresling origami tube is in the second steady state. Based on the second steady state, the Kresling origami tube folds downwards to the limit state, that is, when h is at its minimum value, through torsional compression motion, thus forming the first steady state.

[0020] As a further aspect of the present invention, the third steady state of the Kresling origami tube specifically includes:

[0021] Through further twisting and deformation, the valley creases of the Kresling origami tube are transformed into nearly arc-shaped mountain creases. When the Kresling origami tube in the second steady state is further stretched, its valley crease AC will gradually become an arc-shaped mountain crease, and its two sides △ACD and △ABC will almost merge into a tetrahedral unit under this action; at this time, the Kresling origami tube achieves the third stable state with high stiffness characteristics.

[0022] As a further aspect of the present invention: when the Kresling origami tube is in the third stable state, the crease line AC connecting each cell is modeled, and its arc transformation process is modeled; the midpoint of the arc is defined as F, the radius of the arc is defined as Rˊ, the radian angle is defined as γ, the original crease center point is defined as E, the distance between EF is defined as b, and the center of the arc is defined as O", which lies on the plane coinciding with the perpendicular bisector EF and the structural center line OOˊ; therefore, the radius of the arc and the radian angle can be expressed as:

[0023]

[0024]

[0025] Therefore, the length of arc AC is:

[0026]

[0027] In this state, there is a nonlinear force at the crease line AC that promotes the bending effect, increasing the stiffness of the specific unit surface.

[0028] As a further aspect of the present invention: the special facets of the origami unit reduce the area of ​​△ACD and △ABC at the specific unit facets where the airbag needs to be installed, thereby reducing the reaction force of the origami unit on the airbag, thus enhancing the airbag inflation effect and enabling the specific unit facets to better reach the third steady state.

[0029] The beneficial effects of this invention are:

[0030] 1) This invention uses Kresling origami units as the main driving part, which reduces the interaction force between the robotic arm and the target object during the detection process while ensuring the lightweight of the robotic arm, improves the structural reliability, and effectively adapts to special environments such as microgravity in space.

[0031] 2) This invention utilizes airbag-assisted drive to transform part of the plane of the Kresling origami unit from the second steady state to the third steady state. The high stiffness of the third steady state endows the origami unit with better load-bearing capacity and more diverse motion characteristics. The driving force of the inner cavity of the robotic arm and the selective expansion of the airbag realize the multimodal motion of the robotic arm. At the same time, the robotic arm can be equipped with different external working devices according to different task requirements and special working environments, which greatly improves the practicality of the robotic arm. In addition, the programmability of the airbag expansion and contraction state can realize the flexible adjustment of the structural stiffness of the robotic arm.

[0032] 3) This invention uses a pneumatic method, which has higher stability compared to other driving methods and is also adaptable to the space environment. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the multimodal pneumatic space exploration robotic arm of the present invention.

[0034] Figure 2 This is a structural diagram of the multimodal pneumatic space exploration robotic arm of the present invention;

[0035] Figure 3 Kresling's origami unit diagrams with the same / opposite chirality;

[0036] Figure 4 A diagram of a specific faceted structure for airbag-assisted expansion and deformation in a paper-folding unit;

[0037] Figure 5 This is a diagram of Kresling's origami structure.

[0038] Figure 6 A diagram illustrating the third steady-state deformation principle of Kresling origami;

[0039] Figure 7 This is a schematic diagram illustrating an application scenario of the multimodal pneumatic space exploration robotic arm of the present invention;

[0040] Figure 8 This is a schematic diagram of the second application scenario of the multimodal pneumatic space exploration robotic arm of the present invention.

[0041] In the diagram: 1. Origami unit, 2. End fixing piece, 3. End connector, 4. Middle end support piece, 5. Middle end air inlet piece, 6. Middle end connector, 7. Top connector, 8. Airbag. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1, as Figures 1 to 4 As shown, a multimodal pneumatic origami robot arm based on the origami tristable characteristics includes a robot arm, which includes several origami units 1, and an airbag 8 is provided in the origami unit 1;

[0044] The origami unit 1 is composed of two layers of Kresling origami tubes with the same or opposite chirality and square paper strips. The square paper strips are connected between the Kresling origami tubes. The Kresling origami tubes have three steady states through different bending angles. The origami unit 1 has a cavity inside, and the inner side of the origami unit 1 is formed into a special ridge by bending. The airbag 8 is located on the special ridge inside the origami unit 1 and is connected to an external air source. The Kresling origami tubes can realize the basic motion mode of the robotic arm under the positive and negative pressure drive of the air source. At the same time, the presence of the square paper strips facilitates the connection between Kresling origami tubes and the assembly of the origami unit with the assembly components.

[0045] The robotic arm also includes an end effector 2 and an end effector 3. The end effector 2 is located at the end of the robotic arm and has multiple slots that are interference-fitted with the end air vent. It is mainly used to connect with an external air pipe to provide an air source for the robotic arm. It also has multiple fixing holes to fix the entire robotic arm to a specific space exploration machine. The end effector 3 has multiple protruding cuboids that are interference-fitted with the slots of the end effector 2. The end effector 3 is installed at the bottom of the lower folding unit and serves as a connection and fixation. The end effector 3 has two through holes for ventilation.

[0046] The robotic arm also includes an intermediate end support 4 and an intermediate end air inlet 5. The intermediate end support 4 is located at the upper and lower ends of adjacent folding units 1, and the intermediate end support 4 is interference-fitted with the square paper strip to support the folding unit 1. The intermediate end support 4 is provided with four protruding cuboids for interference-fitting with the intermediate end air inlet 5. The intermediate end support 4 has a circular through hole for ventilation. The intermediate end air inlet 5 is located between two adjacent folding units 2, and the intermediate end air inlet 5 has an external thread and four rectangular slots. Its external thread is used for threaded engagement with the intermediate end connector 6, and the slots are used for interference-fitting with the intermediate end support 4 to achieve the functions of ventilation and connection.

[0047] The robotic arm also includes an intermediate end connector 6 and a top end connector 7. The intermediate end connector 6 is located between adjacent folding units 1 and has four rectangular slots for interference fit with the intermediate end support 4. The intermediate end connector 6 also has an internal threaded hole at its center, which can be threaded into the intermediate air intake 5, mainly for connection and ventilation. The top end connector 7 is located at the top of the robotic arm and has four rectangular slots for interference fit with the intermediate end support 4, which can be used to mount an external space detection device.

[0048] Airbag 8, located on a special ridge inside origami unit 1, such as Figure 4 As shown, its main function is to assist the expansion and deformation of the origami unit 1, which has tristable characteristics, to achieve the switching between the first two stable states and the third stable state of a specific unit surface in Kresling origami, thereby adjusting the structural stiffness and enabling a specific surface to reach the third stable state with high stiffness and stability. The special facets of the origami unit are shown below. Figure 4 As shown, the areas of △ACD and △ABC are reduced at the specific unit surface where the airbag needs to be installed, thereby reducing the reaction force of the origami unit 1 on the airbag 8, thus enhancing the airbag inflation effect and enabling the specific unit surface 1 to better reach the third steady state.

[0049] Under the positive and negative pressure drive of the air source, the internal chamber of the origami unit 1 can realize the contraction and torsion motion modes of the entire robotic arm. At the same time, by utilizing the Kresling origami tristable characteristics and using the airbag 8 for auxiliary drive, a high and low stiffness difference is achieved on the surface of a specific origami unit, thus realizing the bending motion mode of the robotic arm.

[0050] Example 2, in addition to all the technical features included in Example 1, also includes: Figure 5 As shown, a multimodal pneumatic origami robot arm based on the tristable characteristics of origami is presented. Kresling origami consists of multiple arrays of spatial polygons, with key characteristic parameters including the number of sides (n), the side lengths of the upper and lower polygons (AB / CD), and two angles (α and β). Each cell is formed by piecing together two triangles, thus creating two mountain creases (AD / BC) and one valley crease (AC). During the folding process, it exhibits coupled compression and torsion motions, and the crease length can be expressed as:

[0051] L AB =s

[0052]

[0053]

[0054] The circumradius of the upper and lower polygons can be expressed as:

[0055]

[0056] In this invention, the height h and axial rotation angles (α and β) are used to describe the state of the Kresling origami unit. In the parameter selection of the origami unit, α = 46° and β = 46°. The projection of point D onto the lower polygon almost coincides with point B; therefore, ∠AOB = γ and BD = OOˊ = h. Figure 5 As shown, the length of h can be obtained from △ABD and △ABO.

[0057]

[0058] This reveals the mapping relationship between the height and twist angle of the origami unit. In general, the structural parameters of Kresling origami mainly include four constants (n, s, α, β) and three variables (γ, h, d). Figure 5The Kresling origami shown is in its second steady state when its ultimate stretching (h) reaches its maximum value. Torsional compression can be achieved by using a negative pressure air source, folding the origami downwards to its ultimate state. The first steady state is formed when the Kresling origami is compressed to its minimum value (h). Based on the ultimate stretching and torsional motion modes achievable by Kresling origami, the double-layered Kresling origami tubes with the same or opposite chirality described below can also achieve these two basic motion modes.

[0059] The origami unit 1, serving as the main driving component of the multimodal pneumatic space exploration robotic arm of this invention, is composed of two layers of Kresling origami tubes with the same or opposite chirality and square paper strips. This invention features two origami units, which can be equipped with Kresling origami tubes of different chirality according to different motion requirements, thereby achieving different motion modes. Specifically, under the positive and negative drive of the internal air source, the upper layer of the double-layered, opposite-chirality origami unit 1 twists in opposite directions to the lower layer, canceling out the twist angles and thus achieving pure telescopic motion. Figure 3 As shown in the right figure, in the double-layered origami unit 1 with opposite chirality, driven by negative air pressure, the upper origami tube twists to the left and the lower origami tube twists to the right, with the twist angles canceling each other out, achieving a pure contraction motion. In the double-layered origami unit 1 with the same chirality, driven by positive and negative air pressure within the cavity, the upper and lower layers twist in the same direction, and the twist angles cannot cancel each other out, thus achieving a coupled motion of extension and twisting. Figure 3 As shown in the left figure, under the negative pressure of the air source, the upper and lower folding tubes of the double-layered origami unit 1 with the same chirality both twist to the right. The twist angles cannot cancel each other out, thus achieving the coupled motion of contraction and twisting.

[0060] like Figures 5 to 6 It can be seen that when the Kresling origami in the second steady state is further stretched, its straight valley crease AC will gradually stretch outward and become an arc-shaped mountain crease. The two sides △ACD and △ABC will also almost merge into a tetrahedral unit under this action. At this time, the Kresling origami enters a third stable state with high stiffness. In this invention, the valley crease of a specific unit face is stretched outward to form a mountain crease using the airbag 8 inflation assistance, thereby achieving the third steady state. In this state, a nonlinear force exists at the crease line AC that promotes bending, increasing the stiffness of the specific unit face. This increased unit face stiffness will create a stiffness difference in a specific part of the robotic arm, thereby adding a completely new bending motion. The bending direction is the direction directly opposite to the specific facet assisted by the airbag 8 inflation assistance.

[0061] The origami unit 1 in this invention is a double-layered cylindrical shape, with each layer resembling an octagonal prism. To better explain the function of this invention, the facets defined below are surfaces composed of two identical symmetrical triangles. Furthermore, the relative positions of the first and second facets within each origami tube are consistent and have no special significance. Figure 4 As shown, the special facets defined in this invention refer to facets with reduced areas of two triangles, while the specificity of a specific unit facet refers to the characteristics of its position. If the first facet is used as a specific unit facet, the first facet will increase its stiffness when the airbag 8 expands, thereby achieving bending. Compared with the original folding tube, the area of ​​the two symmetrical and identical triangles on the unit facet used to install the airbag 8 is reduced, which reduces the reaction force of the folding unit 1 on the airbag 8, thereby enhancing the expansion effect of the airbag 8 and enabling the specific unit surface to better reach the third steady state.

[0062] For origami unit 1, when the airbag 8 on a specific facet inflates, and the origami tube is driven by negative pressure from the air source, the specific facet will reach a high-stiffness third steady state. Its structural stiffness will be greater than that of other facets in the same layer. Therefore, the origami tube in this layer will bend in the direction directly opposite the specific facet while contracting axially. Specifically, when the first facet reaches the high-stiffness third steady state, due to the difference in stiffness, the origami will bend in the direction of the fifth facet directly opposite the first facet. Similarly, by sequentially inflating the airbags to make the specific facets at different positions reach the high-stiffness third steady state, the origami unit can bend in different directions under negative pressure from the air source. This breaks the limitation of the traditional robotic arm on the degree of freedom. The programmable control of the state of the airbag 8 can also realize full-circumference bending motion.

[0063] Preferably, the origami unit 1 employs a double-layered origami tube with opposite chirality, such as... Figure 3 As shown in the right figure, when driven by negative air pressure, a pure contraction motion is achieved; when driven by positive air pressure, a pure extension motion is achieved.

[0064] Preferably, the origami unit 1 employs a double-layered origami tube with opposite chirality, such as... Figure 3 As shown in the right figure, driven by positive and negative air pressure, the upper paper tube switches from compression to tension, while the lower paper tube switches from tension to compression, thus achieving pure torsional motion.

[0065] Preferably, the origami unit 1 uses a double-layered origami tube with the same chirality, such as... Figure 3 The left figure shows that when the air source is driven by negative pressure, it achieves a coupled motion of contraction and torsion; when the air source is driven by positive pressure, it achieves a coupled motion of stretching and torsion.

[0066] Preferably, when specific facets at the same position on both the upper and lower layers of the origami tube of the origami unit 1 are switched to the third steady state by the expansion of the auxiliary airbag 8, and the positive pressure of the air source is saturated, pure bending motion can be achieved. The bending direction is the direction of the facet directly opposite the specific facet. Selecting specific facets at different positions to switch to the third steady state can achieve bending motion in multiple directions.

[0067] Preferably, the origami unit 1 employs a double-layered origami tube with opposite chirality, such as... Figure 3 As shown in the right figure, when specific facets at the same position on the upper and lower layers of the origami tube are switched to the third steady state by the expansion of the auxiliary airbag 8, when the air source is driven by negative pressure, the contraction and bending coupled motion is realized; when the air source is driven by positive pressure, the stretching and bending coupled motion is realized. The bending direction is the direction that the specific facet is facing. Selecting specific facets at different positions to switch to the third steady state can realize bending motion in multiple directions.

[0068] Preferably, the origami unit 1 employs a double-layered origami tube with opposite chirality, such as... Figure 3 As shown in the right figure, under the positive and negative pressure drive of the air source, the upper folding tube switches from compression to tension. At the same time, the upper specific edge is switched to the third steady state through the expansion of the auxiliary airbag 8, while the lower folding tube switches from tension to compression. This can realize the coupling motion of torsion and bending. The bending direction is the direction that the specific edge is facing. Selecting the specific edge at different positions to switch to the third steady state can realize bending motion in multiple directions.

[0069] Preferably, the origami unit 1 uses a double-layered origami tube with the same chirality, such as... Figure 3 As shown in the left figure, when the air source drives the paper tubes at the same position and the specific edges on the upper and lower layers of the paper tubes are switched to the third steady state by the expansion of the auxiliary airbag 8, the coupled movements of extension, torsion, and bending can be realized. The bending direction is the direction of the edge that the specific edge is facing. Selecting specific edges at different positions to switch to the third steady state can realize bending movements in multiple directions.

[0070] Preferably, when multiple origami units 1 are connected in series, various motion couplings can be achieved, thereby diversifying the motion modes of the robotic arm. This invention, while maintaining a compact and lightweight structure, enriches the motion modes of the robotic arm and significantly improves its operational flexibility in the harsh and complex environment of space.

[0071] Preferably, the motion modes realized based on the single-segment origami unit 1 can be extended to two-segment origami units, i.e., this invention, according to the principle of shape consistency. This enables the multimodal pneumatic space exploration robotic arm of this invention to achieve multimodal motion under the driving force of the central chamber and the selective expansion of the airbag. Among these, multi-directional bending motion is rare in traditional space exploration robotic arms. Furthermore, the motion modes achievable based on the single-segment origami unit can be extended to robotic arms composed of multiple origami units. The motion analysis method is the same as that for the single-segment origami unit, but the analysis steps are more complex and are not described here.

[0072] When the specific facet airbags 8 in the Kresling origami tube are all inflated, the origami unit 1 as a whole is in a third stable state with high stiffness, and the entire robotic arm is also in a third stable state with high stiffness stability, exhibiting high stiffness stability characteristics and high load-bearing capacity at the end.

[0073] Example 3, in addition to all the technical features in Example 1, also includes: a multimodal pneumatic origami robotic arm based on the tristable characteristics of Kresling origami. It uses a Kresling origami unit 1 as the main driving component, ensuring the robotic arm's lightweight design while reducing the interaction force between the robotic arm and the target object during exploration, improving structural reliability, and effectively adapting to special environments such as microgravity in space. Simultaneously, the top connector 8 of the robotic arm can be equipped with different external working devices according to different mission requirements. For complex and variable asteroid surface environments, traditional space exploration devices face difficulties in deep exploration. This invention can equip the top with a miniature probe camera. Relying on the variability of structural stiffness and the diversity of motion modes, it continuously achieves coupling of movements such as extension, bending, and torsion, extending the miniature probe camera into the complex and variable environment. Utilizing the multi-directional bending characteristics of the robotic arm, it completes multi-directional perspective exploration tasks, greatly improving the practicality of the robotic arm. Meanwhile, for small, loose samples on the surface of space, the robotic arm's top connector can be equipped with different types of pneumatic grippers and sampling devices to grasp and sample samples of different shapes from asteroid surfaces, greatly reducing damage to the sample as a whole during the sampling process. For example... Figures 7 to 8 As shown, the end ventilation component 1 of the present invention can be mounted on different probe motion machines to provide diverse motion actions and multi-directional probe perspectives, thereby assisting the probe machines in efficiently completing space exploration missions.

[0074] This invention features an airbag-assisted spatial exploration robotic arm. Under the positive and negative pressure drive of the air source, the internal chamber of the origami unit can realize the contraction and torsion motion modes of the entire robotic arm. At the same time, by utilizing the Kresling origami tristable characteristics and using airbag-assisted drive, a high-low stiffness difference is achieved on the surface of a specific origami unit, thus realizing the bending motion mode of the robotic arm.

[0075] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0076] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A multi-modal aerodynamic space exploration robotic arm based on Kresling origami tri-stable characteristics, comprising a robotic arm, characterized in that: The robotic arm includes several origami units (1), and each origami unit (1) is equipped with an airbag (8). The origami unit (1) is composed of two layers of Kresling origami tubes with the same or opposite chirality and square paper strips. The square paper strips are connected between the Kresling origami tubes. The origami unit (1) has a cavity inside. The Kresling origami tube has three steady states under the driving force of the cavity and the selective expansion of the air bladder. A portion of the inner unit surface of the origami unit (1) forms a special facet by reducing the area of ​​two symmetrical triangles. The air bladder (8) is located on the special facet inside the origami unit (1) and is connected to an external air source. The third steady state of the Kresling origami tube specifically includes: Through further twisting and deformation, the Kresling origami tube transforms the flat valley crease into an almost arc-shaped mountain crease. When the Kresling origami tube in the second steady state is further stretched, its valley crease AC will gradually become an arc-shaped mountain crease, and its two sides △ACD and △ABC will almost merge into a tetrahedral unit under this action; at this time, the Kresling origami tube achieves the third stable state with high stiffness characteristics. When the Kresling origami tube is in its third stable state, the crease line AC connecting each cell is used to model its arc transformation process. The midpoint of the arc is defined as F, the radius as Rˊ, the radian angle as γ, the original crease center point as E, the distance between E and F as b, and the center of the arc as O", which lies on the plane coinciding with the perpendicular bisector EF and the structural centerline OOˊ. Therefore, the radius and radian angle can be expressed as: ； ； Therefore, the length of arc AC is: ； In this state, there is a nonlinear force at the crease line AC that promotes the bending effect and increases the stiffness of the specific unit surface; The special facet of the origami unit (1) reduces the area of ​​△ACD and △ABC at the specific unit face where the airbag (8) needs to be installed, thereby reducing the reaction force of the origami unit (1) on the airbag (8) and thus strengthening the expansion effect of the airbag (8) so that the specific unit face can better reach the third steady state. Here, the special facet refers to the facet with reduced area of ​​the two triangles, and the specific of the specific unit facet refers to the characteristics of the position. If one of the facets is taken as the specific unit facet, the facet will increase the stiffness when the airbag (8) expands, thereby achieving bending.

2. The multi-modal pneumatic space exploration robotic arm of claim 1, wherein: The robotic arm also includes an end-fixed component (2) and an end-connector (3). The end-fixed component (2) is located at the end of the robotic arm and has multiple slots for interference fit with the end-ventilator. The end-connector (3) has multiple protruding cuboids for interference fit with the slots of the end-fixed component (2) and is installed at the bottom of the lower folding unit. The end-connector (3) has two through holes.

3. The multi-modal pneumatic space exploration robotic arm of claim 1, wherein: The robotic arm also includes an intermediate end support (4) and an intermediate end air inlet (5). The intermediate end support (4) is located at the upper and lower ends of adjacent folding units (1), and the intermediate end support (4) is interference-fitted with a square paper strip. The intermediate end support (4) is provided with four protruding cuboids and has a circular through hole. The intermediate end air inlet (5) is located between two adjacent folding units (1) and has an external thread and four rectangular slots.

4. The multimodal pneumatic space exploration robotic arm according to claim 1, characterized in that: The robotic arm also includes an intermediate end connector (6) and a top end connector (7). The intermediate end connector (6) is located between adjacent folding units (1), and the intermediate end connector (6) has four rectangular slots and an internal threaded hole at the center. The top end connector (7) is located at the top of the robotic arm and has four rectangular slots.

5. The multimodal pneumatic space exploration robotic arm according to claim 1, characterized in that: The Kresling origami tube is composed of multiple arrays of spatial polygons. Each polygon's characteristic parameters include the number of sides (n), the side lengths of the upper and lower polygons (AB / CD), and two angles (α and β). Each cell of the spatial polygon array is formed by piecing together two triangles, creating two mountain creases (AD / BC) and one valley crease (AC). During folding, it exhibits coupled compression and torsion movements. The crease length is expressed as: ； ； ； The circumradius of the upper and lower polygons can be expressed as: ； Furthermore, for the first and second steady states, the height h and axial rotation angles (α and β) are used for description, specifically including: In the parameter selection of origami unit (1), the rotation angles (α and β) are determined; the projection of point D onto the lower polygon coincides with point B, therefore ∠AOB=γ, BD=OOˊ=h, and the length of h is obtained through △ABD and △ABO: ； The structural parameters of the Kresling origami tube include four constants (n, s, α, β) and three variables (γ, h, d). When h is at its maximum value, the Kresling origami tube is in the second steady state. Based on the second steady state, the Kresling origami tube folds downwards to the limit state through torsional compression motion, that is, when h is at its minimum value, thus forming the first steady state.

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