A bending and torsion combined soft actuator

Abstract

The present invention provides a bending and twisting combined soft actuator, including a bending and twisting structure, which includes a bending main body, at least two bending units extending outward from the surface of the twisting unit; a top connecting plate, arranged at one end of the bending and twisting structure; a bottom connecting plate, arranged at the other end of the bending and twisting structure; an external air pipe, arranged on the bottom connecting plate; a twisting inner cavity, arranged inside the twisting unit, one end of the twisting inner cavity is closed by the top connecting plate, and the other end is connected to the external air pipe; at least two bending inner cavities are respectively arranged in two bending units, one end of the bending inner cavity is closed by the top connecting plate, and the other end is connected to the external air pipe. By using the present invention, the movement effects of bending and twisting can be achieved simultaneously under the same module, reducing the redundancy of the robot system. At the same time, the structure is simple and can be made in one piece, simplifying the control difficulty of the robot system.

Description

Technical Field

[0001] The invention relates to the field of robot technology, and in particular to a bending and torsion combined soft actuator. Background Art

[0002] In recent years, with the emergence of new materials and the improvement of processing and manufacturing technology, there has been a boom in soft robot research around the world. Soft robots are a new idea in robotics research. Inspired by nature, researchers have begun to explore the design and control of soft robots composed of flexible materials. Modularity has proven practical in soft robots, simplifying control and increasing system redundancy. Soft actuator modules can achieve complex movements with relatively simple control, which has advantages over traditional electromechanical systems. Soft actuator modules are also practical because they are compatible with air pressure and hydraulic pressure generated by various fluids and gases, and have been proven to be a rugged and durable solution for harsh environments.

[0003] Existing software actuation modules can generally only realize bending or twisting movements, but cannot realize bending and twisting movements at the same time in the same module. When bending and twisting movements need to be realized at the same time, the corresponding twisting module and bending module can only be controlled in series, which requires the coordination of the bending cavity and the twisting cavity, which greatly increases the difficulty of control. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a bending-torsion combined soft actuator to solve the technical problem that the existing soft robot module cannot achieve torsion and bending movements in one module at the same time.

[0005] To achieve the above-mentioned and other related purposes, the present invention provides a bending-torsion combined soft actuator, the bending-torsion combined soft actuator comprising:

[0006] A bending and twisting structure, the bending and twisting structure comprising a twisting unit and at least two bending units extending outward from a surface of the twisting unit, and at least two of the bending units are arranged in sequence along the axial direction of the surface of the twisting unit;

[0007] A top connecting plate, arranged at one end of the bending and twisting structure;

[0008] A bottom connecting plate, arranged at the other end of the bending and twisting structure;

[0009] An external air pipe is arranged on the bottom connecting plate;

[0010] A torsion inner cavity is arranged inside the torsion unit, one end of the torsion inner cavity is closed by the top connecting plate, and the other end is connected to the external air pipe;

[0011] At least two curved inner cavities are respectively arranged in the two curved units, one end of the curved inner cavity is closed by the top connecting plate, and the other end is connected to the external air pipe.

[0012] In an optional embodiment, the material of the bending and twisting structure includes elastic material.

[0013] In an optional embodiment, the bent torsion structure includes the torsion unit and a pair of bent units symmetrically extending outward from the surface of the torsion unit; the outer contour line of the radial cross-section of the bent torsion structure includes two major arcs, and the ends of the two major arcs are butted.

[0014] In an optional embodiment, a central limiting column is further provided at the central position of the torsion unit.

[0015] In an optional embodiment, a radial cross-section of the torsional lumen comprises a circle.

[0016] In an optional embodiment, the structure of the bending unit is a wavy non-rotating structure or a corrugated structure.

[0017] In an optional embodiment, a surface of the curved inner cavity away from the torsion unit matches with an outer surface of the corresponding curved unit.

[0018] In an optional embodiment, the bending and twisting structure includes at least three bending units.

[0019] In an optional embodiment, the bending and twisting structure and the top connecting plate are integrally formed, or the top connecting plate and the bending and twisting structure are separately formed and then connected and fixed together.

[0020] In an optional embodiment, the outer surface of the bending unit is further provided with a plurality of arc-shaped protrusions arranged at equal intervals along the axial direction of the bending unit, and the arc-shaped protrusions are perpendicular to the axial direction of the bending unit.

[0021] In an optional embodiment, the torsion unit comprises a hollow cylindrical structure, and a rotating thread protrusion or a rotating thread groove is provided on the inner surface of the torsion unit.

[0022] In an optional embodiment, the rotary thread protrusion includes a multi-thread protrusion; and the rotary thread groove includes a multi-thread groove.

[0023] In an optional embodiment, the multi-threaded protrusions include at least two threaded protrusions that are evenly arranged in the circumferential direction of the inner wall surface of the torsion unit with the central axis of the bending-torsion combined soft actuator as the axis; the multi-threaded grooves include at least two threaded grooves that are evenly arranged in the circumferential direction of the inner wall surface of the torsion unit with the central axis of the bending-torsion combined soft actuator as the axis.

[0024] In an optional embodiment, the rotating thread protrusion and the radial plane of the torsion unit form a preset rotation angle, and the preset rotation angle is greater than 0 and less than 90°.

[0025] The bending and torsion combined soft actuator of the present invention is an elastic structure, does not contain rigid elements, has a simple structure, can be integrally formed, is easy to process and manufacture, and has a large output torque and a high action execution efficiency.

[0026] The bending and twisting combined soft actuator of the present invention can realize bending and twisting movements simultaneously, without the need to control the bending and twisting movements through series connection of different bending modules and twisting modules, thereby reducing the redundancy of the robot structure.

[0027] The bending and twisting combined soft actuator of the present invention can be integrally formed to ensure the stability of the robot joint movement.

[0028] The bending and twisting combined soft actuator of the present invention can be connected in series with a soft manipulator, so as to be used to build a soft robot system platform in combination with a grasping module.

[0029] The bending-torsion combined soft actuator of the present invention has a wide range of applications and can be used in fields with complex environments, such as the deep sea field, the rehabilitation robot field, the minimally invasive surgery field, the rehabilitation medical equipment field, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Shown is a schematic diagram of the three-dimensional structure of the bending and torsion combined soft actuator of the present invention.

[0031] Figure 2 It is a schematic diagram of the three-dimensional structure of the bending-torsion combined soft actuator of the present invention after removing the bottom connecting plate.

[0032] Figure 3 Shown is a right side view of the bending-torsion combined soft actuator of the present invention after the bottom connecting plate is removed.

[0033] Figure 4 The bending and twisting combined with the soft actuator of the present invention is shown along Figure 3 Schematic diagram of the cross section along the AA direction.

[0034] Figure 5It is a three-dimensional structural schematic diagram of a deformation structure of the bending and torsion combined soft actuator of the present invention. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0036] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] See also Figure 1-4 , Figure 1 The three-dimensional structural schematic diagrams of the bending and torsion combined soft actuator of the present invention are shown respectively, Figure 2 The figure shows a three-dimensional structure diagram of the bending-torsion combined soft actuator of the present invention after the bottom connecting plate is removed. Figure 3 Shows Figure 2 Right view of Figure 4 The bending and twisting combined with the soft actuator of the present invention is shown along Figure 3 Schematic diagram of the cross section in the AA direction. Figure 1-4 The bending and twisting soft actuator of the present invention comprises a bending and twisting structure, a top connecting plate 1 and a bottom connecting plate 4 respectively arranged at the two ends of the bending and twisting structure, and an external air pipe arranged on the bottom connecting plate 4. The bending and twisting soft actuator of the present invention can realize the bending and twisting motion effects at the same time under the same module, without the need to control the bending and twisting motions through the series connection of different bending modules and twisting modules, thereby reducing the redundancy of the robot structure.

[0039] See also Figure 1-4 In the present invention, the bending and twisting structure includes a twisting unit 3 and a pair of bending units 2a and 2b symmetrically extending outward from the surface of the twisting unit 3; a twisting inner cavity 31 is arranged inside the twisting unit 3, one end of the twisting inner cavity 31 is closed by the top connecting plate 1, and the other end is connected to the first external air pipe 5; the pair of bending units 2a and 2b are respectively provided with bending inner cavities 22a and 22b, one end of the bending inner cavities 22a and 22b is closed by the top connecting plate 1, and the other end is connected to the second external air pipe 6. The present invention drives the twisting inner cavity 31 and the bending inner cavities 22a and 22b by pressure, and can realize bending and twisting deformation movements of different angles without additional transmission elements.

[0040] See also Figure 1-4 In this embodiment, the torsion unit 3 and a pair of bending units 2a and 2b form an "8"-shaped bending torsion structure, and the bending torsion structure can be regarded as being formed by the butt joint of the ends of two major arcs under the profile of the cross section perpendicular to the axial direction (i.e., the radial cross section) (it can be understood that in other examples, the ends of the two major arcs can also be connected by other arcs). Among them, the torsion unit 3 is a hollow cylindrical structure, and the torsion unit 3 is located at the center of the bending torsion structure. The cross section of the torsion inner cavity 31 of the torsion unit 3 in the radial direction can be, for example, circular.

[0041] See also Figure 1-4In this embodiment, a rotating thread protrusion 31 is provided on the inner surface of the torsion unit 3. The rotating thread protrusion 31 can be, for example, a multi-thread thread protrusion, which includes at least two thread protrusions that are evenly arranged on the circumferential direction of the inner surface of the bending unit at equal intervals with the axis of the bending unit as the axis. The tooth shape of the rotating thread protrusion 31 can be, for example, a triangular, trapezoidal, rectangular, serrated or arc thread protrusion; in other words, a rotating thread groove 32 is provided on the inner surface of the torsion unit 3. The rotating thread groove 32 can be, for example, a multi-thread thread groove, which includes at least two thread grooves that are evenly arranged on the circumferential direction of the inner surface of the bending unit at equal intervals with the axis of the bending unit as the axis, and there is a thread groove between two adjacent thread protrusions. The rotating thread protrusion 31 and the radial plane of the torsion unit 3 form a preset rotation angle, and the preset rotation angle is greater than 0 and less than 90°. Preferably, the preset rotation angle can be, for example, greater than or equal to 15° and less than or equal to 45°, such as 15°, 20°, 25°, 30°, 35°, 40°, 45°, etc. It should be noted that the preset rotation angle can be defined as the angle between the thread line of the rotating thread protrusion 31 and the radial plane of the torsion unit 3 after the torsion unit 3 is unfolded along the circumferential surface and the thread line of the rotating thread protrusion 31 is in a straight line.

[0042] It should be noted that the number of thread protrusions of the multi-threaded protrusions may be related to the inner diameter of the torsion inner cavity 31 of the torsion unit 3, and the number of thread protrusions of the multi-threaded protrusions may be positively correlated with the inner diameter of the torsion inner cavity 31 of the torsion unit 3. As an example, when the inner (straight) diameter of the torsion inner cavity 31 is 46 mm, the multi-threaded protrusions include 24 thread protrusions to achieve a better torsion effect. It should be noted that the use of multi-threaded protrusions can avoid the problem of the torsion axis deviating from the axis of the bending torsion combined soft robot module when the torsion is loaded when a single-threaded protrusion is used. The deviation of the torsion axis will affect the performance of the soft robot module.

[0043] See also Figure 1-4In this embodiment, the pair of bending units 2a and 2b are symmetrically arranged on the upper and lower sides of the torsion unit 3, and are defined as the first bending unit 2a and the second bending unit 2b, respectively. The surface of the bending inner cavity of the first bending unit 2a (defined as the first bending inner cavity 22a) / the bending inner cavity of the second bending unit 2b (defined as the second bending inner cavity 22b) away from the torsion unit 3 is parallel to the outer surface of the first bending unit 2a / the second bending unit 2b, that is, the two match each other, so that the wall thickness of the bending unit at this position can be guaranteed to be equal, which is conducive to better control of the bending action of the soft robot module. As an example, the radial cross-section of the first bending inner cavity 22a can be, for example, a figure surrounded by a top arc and its opposite chord, and the top arc is parallel to the outer surface of the first bending unit 2a to ensure that the wall thickness of the first bending unit 2a at the top arc is the same. As an example, the radial cross-section of the second curved inner cavity 22b can be a figure surrounded by a top arc and its chord, and the top arc is parallel to the outer surface of the second curved unit 2b to ensure that the wall thickness of the second curved unit 2b at the top arc is the same.

[0044] See also Figure 1-4 In this embodiment, a plurality of first arc-shaped protrusions 21a are arranged on the outer surface of the first bending unit 2a at equal intervals along the axial direction of the first bending unit 2a, and the first arc-shaped protrusions 21a are perpendicular to the axial direction of the first bending unit 2a. The cross-section of the first arc-shaped protrusions 21a may be, for example, a triangle, a trapezoid, a rectangle, a sawtooth or a circular arc, and may be other suitable shapes; a plurality of second arc-shaped protrusions 21b are arranged on the outer surface of the second bending unit 2b at equal intervals along the axial direction of the second bending unit 2b, and the second arc-shaped protrusions 21b are perpendicular to the axial direction of the second bending unit 2b, and the cross-section of the second arc-shaped protrusions 21b may be, for example, a triangle, a trapezoid, a rectangle, a sawtooth or a circular arc, and may be other suitable shapes. As an example, Figure 1 and 2 As shown, the first arc-shaped protrusion 21a and the second arc-shaped protrusion 21b are symmetrical structures (in some embodiments, they can also be asymmetrical structures).

[0045] It should be noted that the structures of the first bending unit 2a and the second bending unit 2b are Figure 1-4In addition to the structure shown, the structure of the first bending unit 2a and the second bending unit 2b can also be, for example, a wavy non-rotating body structure or a corrugated structure; when the structure of the first bending unit 2a and the second bending unit 2b is a wavy non-rotating body structure, the outer wall of the bending unit 2a / 2b is composed of a peak structure and a trough structure arranged at intervals along the axial direction of the bending-torsion combined soft actuator; when the structure of the first bending unit 2a and the second bending unit 2b is a corrugated structure, the outer wall of the bending unit 2a / 2b can, for example, be composed of a plurality of corrugated sections arranged in sequence along the axial direction of the bending-torsion combined soft robot module.

[0046] See also Figure 2 and 4 In this embodiment, a central limiting column 7 is further provided at the central position of the torsion unit 3, which serves to enhance rigidity and overload protection; an intermediate through hole (not shown in the figure) of the bottom connecting plate 4, the central limiting column 7 and the top connecting plate 1 can be formed in the central limiting column 7 in sequence, so that when connected in series with other grasping modules, it can also serve to place a connecting airway and other communication equipment; it can be understood that the intermediate through hole of the central limiting column 7 can also be used as a channel for accommodating fingers or limbs, so that the bending and torsion combined with soft brake can be used as a rehabilitation device for fingers or limbs.

[0047] In the present invention, please refer to Figure 1 and Figure 2 and 4 The top connecting plate 1 and the bending and twisting structure may be integrally formed, or the top connecting plate 1 and the bending and twisting structure may be formed separately, and then the two may be fixedly connected together by gluing, binding or the like.

[0048] In the present invention, please refer to Figure 1 , the shape of the bottom connecting plate 4 matches the end shape of the bending torsion structure, and also has an "8"-shaped outer contour. A plurality of first external air pipes 5 and at least two second external air pipes 6 are arranged on the bottom connecting plate 4, the first external air pipe 5 is connected to the torsion inner cavity 31, at least one of the second external air pipes 6 is connected to one of the pair of bending inner cavities 22a, 22b, and the number of the first external air pipes 5 and the second external air pipes 6 can be adjusted as needed. As an example, the first external air pipe 5 may include, for example, 4, which are evenly arranged on the surface of the bottom connecting plate 4 along the circumferential direction, and the fluid can be uniformly filled into or extracted from the torsion inner cavity 31 at the same time through the 4 first external air pipes 5 to improve the torsion control accuracy of the soft robot module. As an example, the second external air pipe 6 may include, for example, 2, which are respectively connected to the first bending inner cavity 22a and the second bending inner cavity 22b.

[0049] See also Figure 1-4 In the present invention, the material of the bending and torsion structure may be, for example, an elastic material, so that bending and torsion may occur more easily under loading; the material of the top connecting plate 1 and the bottom connecting plate 4 may be, for example, an elastic material or a non-axially stretchable material.

[0050] During operation, when the torsion inner cavity 31 of the torsion unit 3 is filled with fluid (the fluid may be, for example, gas, liquid or other fluid capable of actuating deformation), the torsion unit 3 begins to expand, and its main body extends in a direction perpendicular to the distribution of the rotating thread protrusions 31. Due to the strain difference generated by the rotating thread protrusions 31 structure under the pressurized state, the torsion motion is deflected according to the arrangement of the rotating thread protrusions 31. When the first bending inner cavity 22a is filled with fluid, the first arc-shaped protrusion 21a provided on the outer surface of the first bending unit 2a will limit the expansion of the first bending unit 2a, so that the bending torsion structure soft brake is bent downward as a whole; and when the second bending inner cavity 22b is filled with fluid, the second arc-shaped protrusion 21b provided on the outer surface of the second bending unit 2b will limit the expansion of the second bending unit 2b, so that the bending torsion structure soft brake is bent upward as a whole. When fluid is simultaneously filled into the torsion inner cavity 31 and any one of the bending inner cavities 31 (the first bending inner cavity 22a or the second bending inner cavity 22b), the bending-twisting structure soft brake can generate both bending and twisting.

[0051] See also Figure 5 The present invention also introduces another soft brake with bending and torsion structure. Figure 1-4 Compared with the structure shown in FIG. 1 , the number of bending units is three or more. For details, please refer to Figure 5The bending and twisting structure includes a twisting unit 3 and three bending units 2a, 2b, and 2c extending outward from the surface of the twisting unit 3, and the three bending units 2a, 2b, and 2c are arranged in sequence along the circumferential direction of the surface of the twisting unit 3; a twisting inner cavity 31 is arranged inside the twisting unit 3, one end of the twisting inner cavity 31 is closed by the top connecting plate 1, and the other end is connected to the first external air pipe 5; the three bending units 2a, 2b, and 2c are respectively provided with bending inner cavities 22a, 22b, and 22c, one end of the bending inner cavity 22a, 22b, and 22c is closed by the top connecting plate 1, and the other end is connected to the second external air pipe 6. On the outer surface of the bending unit 2a / 2b / 2c, there are provided a plurality of arc-shaped protrusions 21a / 22b / 22c arranged at equal intervals along the axial direction of the bending unit 2a / 2b / 2c, the arc-shaped protrusions 21a / 22b / 22c are perpendicular to the axial direction of the bending unit 2a / 2b / 2c, and the cross-section of the arc-shaped protrusions 21a / 22b / 22c can be, for example, a triangle, a trapezoid, a rectangle, a sawtooth or a circular arc, and can be other suitable shapes. When the number of bending units in the bending torsion structure soft brake is greater than or equal to three, the bending torsion structure soft brake can achieve omnidirectional bending movement.

[0052] The bending and torsion combined soft actuator of the present invention is an elastic structure, does not contain rigid elements, has a simple structure, can be integrally formed, is easy to process and manufacture, and has a large output torque and a high efficiency of action execution. The bending and torsion combined soft actuator of the present invention can realize bending and torsion movements at the same time, without the need to control the bending and torsion movements through series connection of different bending modules and torsion modules, thereby reducing the redundancy of the robot structure. The bending and torsion combined soft actuator of the present invention can be integrally formed to ensure the stability of the robot joint movement. The bending and torsion combined soft actuator of the present invention can be connected in series with a soft manipulator, so as to be used to build a soft robot system platform in combination with a grasping module. The bending and torsion combined soft actuator of the present invention has a wide range of applications and can be used in fields with complex environments, such as the deep sea field, the rehabilitation robot field, the minimally invasive surgery field, the rehabilitation medical equipment field, etc.

[0053] It should be noted that in the present invention, in addition to the structures of the above embodiments one to three, the bending unit may also be in other shapes, such as a wave crest structure of a rectangle, a cone, etc., or a bending unit of a fiber-constrained structure, etc.

[0054] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

[0055] In the description herein, many specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of the specific details or with other devices, systems, components, methods, components, materials, parts, etc. In other cases, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0056] References throughout this specification to "one embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention, and not necessarily in all embodiments. Thus, various appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout this specification do not necessarily refer to the same embodiment. In addition, the particular features, structures, or characteristics of any specific embodiment of the invention may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the invention described and illustrated herein may be possible in light of the teachings herein and are to be considered part of the spirit and scope of the invention.

[0057] It should also be understood that one or more of the elements shown in the figures may also be implemented in a more separate or more integrated manner, or even removed because they are inoperable in certain circumstances or provided because they may be useful depending on the application.

[0058] In addition, unless otherwise explicitly indicated, any marking arrows in the drawings should be regarded as exemplary only and not limiting. In addition, unless otherwise indicated, the term "or" used herein is generally intended to mean "and / or". In the case where the term is not clear because it is anticipated that the ability to separate or combine is provided, the combination of components or steps will also be regarded as indicated.

[0059] As used in the description herein and throughout the claims that follow, "a", "an", and "the" include plural references unless otherwise indicated. Likewise, as used in the description herein and throughout the claims that follow, the meaning of "in" includes "in" and "on" unless otherwise indicated.

[0060] The above description of the illustrated embodiments of the present invention (including that described in the Abstract) is not intended to be exhaustive or to limit the present invention to the precise form disclosed herein. Although specific embodiments of the present invention and examples of the present invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention as will be recognized and appreciated by those skilled in the art. As noted, these modifications may be made to the present invention in accordance with the above description of the embodiments described herein, and these modifications will be within the spirit and scope of the present invention.

[0061] Systems and methods have been generally described herein as details that aid in understanding the present invention. In addition, various specific details have been given to provide an overall understanding of embodiments of the present invention. However, those skilled in the relevant art will recognize that embodiments of the present invention may be practiced without one or more of the specific details, or may be practiced using other devices, systems, accessories, methods, components, materials, parts, etc. In other cases, well-known structures, materials, and / or operations are not specifically shown or described in detail to avoid confusion with various aspects of embodiments of the present invention.

[0062] Thus, although the invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are intended within the foregoing disclosure, and it should be understood that in some cases, some features of the invention will be employed without the corresponding use of other features without departing from the scope and spirit of the proposed invention. Thus, many modifications may be made to adapt a particular environment or material to the essential scope and spirit of the invention. The invention is not intended to be limited to the specific terms used in the claims below and / or the specific embodiments disclosed as the best mode contemplated for carrying out the invention, but the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Thus, the scope of the invention will be determined solely by the appended claims.

Claims

1. A bending-torsion combined soft actuator, characterized in that: The bending and torsion combined soft actuator comprises: A bending and twisting structure, the bending and twisting structure comprising a twisting unit and at least two integrally formed bending units extending outwardly from an outer surface of the twisting unit, and the bending units are arranged axially along the surface of the twisting unit; A top connecting plate, arranged at one end of the bending and twisting structure; A bottom connecting plate, arranged at the other end of the bending and twisting structure; An external air pipe is arranged on the bottom connecting plate; A torsion inner cavity is arranged inside the torsion unit, one end of the torsion inner cavity is closed by the top connecting plate, and the other end is connected to the external air pipe; At least two curved inner cavities are respectively arranged in the two curved units, one end of the curved inner cavity is closed by the top connecting plate, and the other end is connected to the external air pipe; Wherein, the torsion unit comprises a hollow cylindrical structure, and a rotating thread protrusion is arranged on the inner surface of the torsion unit; the rotating thread protrusion comprises a multi-thread protrusion.

2. The bending-torsion combined soft actuator according to claim 1, characterized in that: The material of the bending and twisting structure includes elastic material.

3. The bending-torsion combined soft actuator according to claim 1, characterized in that: The bending torsion structure comprises the torsion unit and a pair of bending units symmetrically extending outward from the surface of the torsion unit; the outer contour line of the radial cross section of the bending torsion structure comprises two major arcs, and the ends of the two major arcs are butted.

4. The bending-torsion combined soft actuator according to claim 1, characterized in that: The bending-twisting structure includes at least three bending units.

5. The bending-torsion combined soft actuator according to claim 1, characterized in that: The surface of the curved inner cavity away from the twisting unit matches the outer surface of the corresponding bending unit.

6. The bending-torsion combined soft actuator according to claim 1, characterized in that: The bending and twisting structure and the top connecting plate are integrally formed, or the top connecting plate and the bending and twisting structure are separately formed and then connected and fixed together.

7. The bending-torsion combined soft actuator according to claim 1, characterized in that: The outer surface of the bending unit is further provided with a plurality of arc-shaped protrusions arranged at equal intervals along the axial direction of the bending unit, and the arc-shaped protrusions are perpendicular to the axial direction of the bending unit.

8. The bending-torsion combined soft actuator according to claim 1, characterized in that: The bending unit includes a wave-shaped non-rotating structure or a corrugated structure.

9. The bending-torsion combined soft actuator according to claim 1, characterized in that: The multi-threaded protrusions include at least two threaded protrusions which are evenly arranged on the circumferential direction of the inner wall surface of the torsion unit with equal spacing around the central axis of the bending and torsion combined soft actuator.

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