Modular variable stiffness pneumatic soft actuator and soft robot

Abstract

A modular variable stiffness pneumatic soft actuator, comprising a gas-driven bending member (1), a connecting mechanism (3), a variable stiffness mechanism (4), and a deformation limiting member (2). A cavity is formed inside the gas-driven bending member, and an external independent gas source is communicated with the cavity in the gas-driven bending member. The deformation limiting member is located on one side of the gas-driven bending member, and the connecting mechanism is located on the other side of the deformation limiting member. The variable stiffness mechanism comprises a plurality of variable stiffness members, and one of the plurality of variable stiffness members is mounted on the other side of the connecting mechanism. Further provided is a soft robot. By selecting the variable stiffness mechanism having different equivalent densities, the soft actuator changes the stiffness of the gas-driven soft actuator, achieves a variable stiffness design of the soft robot, and thereby achieves flexible control of the stiffness of the soft robot.

Description

Modular variable stiffness pneumatic soft actuator and soft robot

[0001] The present application claims priority to the Chinese patent application No. 2024107674583, filed on June 14, 2024, and entitled "A modular variable stiffness pneumatic soft actuator and soft robot", the whole content or part of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of soft robot, and particularly relates to a modular variable stiffness pneumatic soft actuator and soft robot. BACKGROUND

[0003] The soft robot is a robot made of elastic material, the body of which is soft and easy to deform under external force. It has good wear resistance and is not easy to damage the workpiece during work. It is necessary to design a soft robot body with excellent performance for the application and development of the soft robot.

[0004] The high flexibility and high environmental adaptability of the soft robot itself enable it to enter a small and limited space to complete a specific work. However, due to the easy deformation of the soft robot material, the carrying capacity and output force of the soft robot are limited in a relatively low range. In order to improve the stiffness of the soft robot while maintaining its flexibility and softness, it is necessary to innovatively design the variable stiffness of the soft robot, which is conducive to the application and development of the soft robot.

[0005] In the current variable stiffness method based on the interaction of the structure before the stiffness change, it can be mainly divided into antagonistic action and blocking action. In the variable stiffness method based on blocking action, the active particle blocking method and the layer blocking method need an additional negative pressure extraction device, which is not conducive to miniaturization and light weight; the passive particle blocking method has limited variable stiffness effect and cannot change the stiffness at will. In the variable stiffness method based on antagonistic action, the existing structure mainly realizes the increase of stiffness to a certain extent by forming the antagonistic action between the structures, and the variable stiffness effect is limited. SUMMARY

[0006] The present application provides a modular variable stiffness pneumatic soft actuator and soft robot to improve the variable stiffness effect of the soft robot.

[0007] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0008] In one aspect, the present application provides a modular variable stiffness pneumatic soft actuator, comprising:

[0009] The gas-driven bending piece is composed of an elastic driving piece and a solid connecting body fixed at the bottom of the elastic driving piece; the elastic driving piece has a cavity formed inside; an external independent gas source is in communication with the cavity inside the elastic driving piece of the gas-driven bending piece; the deformation of the elastic driving piece under the gas pressure is limited by the solid connecting body, so that the gas-driven bending piece is bent under the action of the gas pressure.

[0010] The deformation limiting piece is arranged on the bottom surface of the gas-driven bending piece and is arranged along the length direction of the gas-driven bending piece to limit the elongation of the gas-driven bending piece.

[0011] The connecting mechanism is arranged on the bottom surface of the deformation limiting piece.

[0012] The variable stiffness mechanism includes a plurality of variable stiffness pieces, and the plurality of variable stiffness pieces are selectively installed at the bottom of the connecting mechanism.

[0013] Further, the pneumatic soft actuator further includes a first end fixing mechanism, and the first end fixing mechanism includes two first fixing parts.

[0014] The two first fixing parts are respectively fixedly installed at two ends in the length direction of the gas-driven bending piece, and one of the first fixing parts is provided with a gas hole in communication with the external independent gas source to realize the communication between the external independent gas source and the cavity inside the gas-driven bending piece.

[0015] Further, the connecting mechanism includes:

[0016] The first connecting piece is fixedly arranged on one side of the deformation limiting piece.

[0017] The second connecting piece is fixedly arranged on one side of the variable stiffness mechanism.

[0018] The second connecting piece is detachably installed on the first connecting piece to facilitate the disassembly of the variable stiffness mechanism.

[0019] Further, the pneumatic soft actuator further includes a second end fixing mechanism, and the second end fixing mechanism includes two second fixing parts.

[0020] The two second fixing parts are respectively fixedly installed at two ends in the length direction of the first connecting piece.

[0021] Further, a plurality of recessed clamping grooves are formed on the bottom surface of the first connecting piece, and a plurality of convex clamping buckles matched with the recessed clamping grooves are formed on the top surface of the second connecting piece.

[0022] The plurality of convex clamping buckles on the second connecting piece are respectively clamped in the plurality of recessed clamping grooves of the first connecting piece, so that one of the variable stiffness pieces of the variable stiffness mechanism is detachably installed on the first connecting piece at the bottom of the gas-driven bending piece by the second connecting piece at the top.

[0023] Further, a plurality of first through holes are formed on the variable stiffness members of the variable stiffness mechanism, and the cross-sectional area of the first through holes gradually decreases until disappearing completely, so that the equivalent densities of the plurality of variable stiffness members are different.

[0024] Further, the gas-driven bending member, the connecting mechanism and the variable stiffness mechanism are made of elastic material, an external independent gas source provides pressurized gas into the cavity of the gas-driven bending member, so that the gas-driven bending member is bent under the action of the pressurized gas; after the pressurized gas is removed, the gas-driven bending member returns to its original state.

[0025] Further, the thickness of the deformation limiting member is 0.05-2mm, and the material is paper or glass fiber or other material that is not easy to be stretched.

[0026] Further, the pneumatic soft actuator further comprises a third end fixing mechanism, and the third end fixing mechanism comprises two third fixing parts.

[0027] The two third fixing parts are respectively fixedly installed at two ends in the length direction of the variable stiffness mechanism.

[0028] Another aspect of the present application also provides a variable stiffness soft robot, which comprises the above-mentioned pneumatic soft actuator and a base, and a plurality of pneumatic soft actuators are installed on the base.

[0029] Further, the number of the pneumatic soft actuators is three, and the three pneumatic soft actuators are arranged in a circle around the central axis of the base; the gas source of the three pneumatic soft actuators on the soft robot comes from an external gas source, and the air pressure in the three pneumatic soft actuators is controlled by three independent gas sources respectively.

[0030] The variable stiffness mechanisms on the three pneumatic soft actuators are installed on the base in a posture facing the central axis of the base.

[0031] Alternatively, the variable stiffness mechanisms on the three pneumatic soft actuators are installed on the base in a posture away from the central axis of the base.

[0032] Alternatively, the variable stiffness mechanisms on the three pneumatic soft actuators are installed on the base in a posture facing and / or away from the central axis of the base.

[0033] Further, the soft robot further comprises a plurality of connecting members and end supports corresponding to the number of the pneumatic soft actuators respectively.

[0034] The base is formed with a connecting portion and a plurality of supporting portions, the base is connected with an external device through the connecting portion, the plurality of supporting portions are arranged around the connecting portion, and the plurality of pneumatic soft actuators are respectively detachably installed on the plurality of supporting portions of the base through the plurality of connecting pieces, so that the pose adjustment of the plurality of pneumatic soft actuators is realized.

[0035] The present application has the following advantages:

[0036] 1. The present application provides a pneumatic soft actuator, which has the following advantages:

[0037] a. By selecting variable stiffness mechanisms with different equivalent densities, the stiffness of the pneumatic soft actuator can be changed, realizing the variable stiffness design of the pneumatic soft actuator. When the pneumatic soft actuator needs flexible movement and lower load, a variable stiffness mechanism with lower equivalent density is selected, at this time, the pneumatic soft actuator body is lighter and easier to deform; when the pneumatic soft actuator needs higher load capacity and larger output force, a variable stiffness mechanism with higher equivalent density is selected, at this time, the pneumatic soft actuator body has larger stiffness and higher load capacity. By selecting and installing variable stiffness mechanisms with different equivalent densities, the stiffness of the pneumatic soft actuator can be flexibly controlled;

[0038] b. The connecting mechanism on the present application is inspired by the design of mortise and tenon structure, which can be reversibly disassembled;

[0039] c. The present application designs variable stiffness mechanisms with different stiffness by changing the equivalent density of the variable stiffness mechanism; the stiffness of these variable stiffness mechanisms changes with the change of the equivalent density; so that the present application is suitable for a variety of different working environments;

[0040] 2. The present application also provides a variable stiffness soft robot, which can configure its stiffness and load capacity according to the application scene and task requirements. By dynamically selecting variable stiffness mechanisms with different stiffness, the stiffness of the soft robot can be flexibly customized, realizing the adaptation and grasping of different weight loads.

[0041] The soft robot also has the following advantages:

[0042] The grasping radius is adjustable, a plurality of pneumatic soft actuators are respectively installed on a plurality of supporting portions of the base through a plurality of connecting pieces, and the plurality of connecting pieces are respectively detachably installed on the plurality of supporting portions of the base; when facing different diameter grasping objects, the position of the connecting piece can be adjusted to adjust the grasping radius of the soft robot, which enhances the grasping ability of the soft robot.

[0043] The grasping effect can be adjusted, the connecting piece of the soft robot can be flexibly adjusted in the installation direction, when the installation direction of the connecting piece is adjusted, the grasping effect of the pneumatic soft robot will change. According to the use scene, the installation direction of one or more connecting pieces can be adjusted, so that the soft robot can meet various different use scenes. BRIEF DESCRIPTION OF DRAWINGS

[0044] Fig. 1 is a schematic diagram of the overall structure of the pneumatic soft actuator in the application;

[0045] Fig. 2 is a partial sectional view of the pneumatic soft actuator in the application;

[0046] Fig. 3 is a schematic diagram of the structure of the gas-driven bending piece in the application;

[0047] Fig. 4 is an enlarged schematic diagram of the first connecting piece in the application;

[0048] Fig. 5 is an enlarged schematic diagram of the second connecting piece in the application;

[0049] Fig. 6 is an enlarged schematic diagram of the variable stiffness mechanism in the application;

[0050] Fig. 7 is a schematic diagram of the first structure of the soft robot in the embodiment of the application;

[0051] Fig. 8 is a partial enlarged schematic diagram of part A in Fig. 7;

[0052] Fig. 9 is a schematic diagram of the second structure of the soft robot in the embodiment of the application;

[0053] Fig. 10 is a schematic diagram of the structure of the base in the application;

[0054] Fig. 11 is an enlarged view of the bottom view of the connecting piece in the application;

[0055] Fig. 12 is an enlarged view of the isometric view of the connecting piece in the application;

[0056] Fig. 13 is a schematic diagram of the structure of the end support in the application.

[0057] Explanation of reference signs: 1, air driving bending piece; 2, deformation limiting piece; 3, connecting mechanism; 31, first connecting piece; 311, concave clamping groove; 32, second connecting piece; 321, convex buckle; 4, variable stiffness mechanism; 5, first end fixing mechanism; 51, air hole; 52, third fixing hole; 6, second end fixing mechanism; 61, fourth fixing hole; 7, third end fixing mechanism; 71, fifth fixing hole; 8, base; 81, round handle; 82, support; 821, rectangular groove; 822, first fixing hole; 83, square handle; 831, second fixing hole; 9, connecting piece; 91, through groove; 92, first connecting hole; 93, rectangular hole; 94, round hole; 95, second connecting hole; 96, third connecting hole; 10, end support; 101, fourth connecting hole; 102, fifth connecting hole. DETAILED DESCRIPTION

[0058] For the purpose of promoting an understanding of the principles of the application, reference will now be made to the embodiments illustrated in the drawings. It is expressly understood that the drawings are only meant to illustrate preferred embodiments of the application and that the application can take many different forms. In addition, it should be understood that the drawings are not to scale and that the specific dimensions are not to be construed as limiting.

[0059] It should be noted that when an element is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or indirectly on or connected to the other element by way of one or more other elements. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element by way of one or more other elements.

[0060] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, merely describe the orientation in the drawings in which the application is shown and do not limit the application therto. The application can be implemented in any orientation.

[0061] In addition, the terms "first", "second", and the like, do not denote any quantity or importance, but rather are used to distinguish one element from another, and are not meant to limit the application. Thus, a feature defined with "first" or "second" can include one or more of the features. In the description of the application, the meaning of "a plurality" is two or more, unless otherwise expressly specified.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. The use herein of the terms "and / or" includes a set of one or more associated listed items.

[0063] It should also be noted that the same reference signs are used in all the drawings for the same or similar parts or components, and for the same components in the embodiments of the present application, only one of the components or parts may be labeled with a reference sign in the drawings, and it should be understood that the reference sign is applicable to other identical components or parts.

[0064] Referring to FIGS. 1-2, the present application provides a modular variable stiffness pneumatic soft actuator, comprising:

[0065] The gas-driven bending member 1 is composed of an elastic driving member and a solid connecting body fixed to the bottom of the elastic driving member; the elastic driving member has a cavity formed therein, and an external independent gas source is in communication with the cavity in the elastic driving member of the gas-driven bending member 1; the deformation of the elastic driving member under gas pressure is limited by the solid connecting body, so that the gas-driven bending member 1 bends under the action of gas pressure.

[0066] The deformation limiting member 2 is arranged on the bottom surface of the gas-driven bending member 1 to limit the elongation of the gas-driven bending member 1.

[0067] The connecting mechanism 3 is arranged on the bottom surface of the deformation limiting member 2.

[0068] The variable stiffness mechanism 4 includes a plurality of variable stiffness members, and the plurality of variable stiffness members are selectively installed at the bottom of the connecting mechanism 3.

[0069] In some embodiments, referring to FIGS. 1 and 2, the pneumatic soft actuator further comprises a first end fixing mechanism 5, and the first end fixing mechanism 5 includes two first fixing parts.

[0070] The two first fixing parts are respectively fixedly installed at two ends in the length direction of the gas-driven bending member 1, and one of the first fixing parts is provided with a gas hole 51, which is in communication with the external independent gas source to realize the communication between the external independent gas source and the cavity in the gas-driven bending member 1.

[0071] In some embodiments, referring to FIGS. 2, 4 and 5, the connecting mechanism 3 includes:

[0072] The first connecting member 31 is fixedly arranged on one side of the deformation limiting member 2.

[0073] The second connecting member 32 is fixedly arranged on one side of the variable stiffness mechanism 4, and is detachably mounted on the first connecting member 31 to facilitate disassembly of the variable stiffness mechanism. In some embodiments, a plurality of recessed clamping grooves 311 are formed on the bottom surface of the first connecting member 31, and a plurality of protruding buckles 321 adapted to the recessed clamping grooves 311 are formed on the top surface of the second connecting member 32.

[0074] The plurality of protruding buckles 321 on the second connecting member 32 are clamped in the plurality of recessed clamping grooves 311 of the first connecting member 31, so that one of the variable stiffness members of the variable stiffness mechanism 4 is detachably mounted on the first connecting member 31 at the bottom of the gas-driven bending member 1 by the second connecting member 32 at the top.

[0075] In some embodiments, referring to FIGS. 1 and 2, the pneumatic soft actuator further comprises a second end fixing mechanism 6, which includes two second fixing parts.

[0076] The two second fixing parts are fixedly mounted on the two ends in the length direction of the first connecting member 31. In some embodiments, referring to FIGS. 1 and 6, a plurality of first through holes are formed on at least part of the variable stiffness members of the variable stiffness mechanism 4, and the cross-sectional areas of the first through holes on the plurality of variable stiffness members gradually decrease until completely disappear, so that the equivalent densities of the plurality of variable stiffness members are different.

[0077] In some embodiments, referring to FIGS. 1 and 2, the pneumatic soft actuator further comprises a third end fixing mechanism 7, which includes two third fixing parts.

[0078] The two third fixing parts are fixedly mounted on the two ends in the length direction of the variable stiffness mechanism 4.

[0079] In some embodiments, the gas-driven bending member 1, the connecting mechanism 3, and the variable stiffness mechanism 4 are all made of elastic material. An external independent gas source provides pressurized gas into the cavity of the gas-driven bending member 1, so that the gas-driven bending member 1 is bent under the action of the pressurized gas. After the pressurized gas is removed, the gas-driven bending member 1 returns to its original state.

[0080] In some embodiments, the thickness of the deformation limiting member 2 is 0.05-2 mm, and the material thereof is paper or glass fiber, which is not easy to be stretched.

[0081] The working principle of the pneumatic soft actuator is as follows:

[0082] The air-driven bending piece 1 is made of elastic material, and is composed of an elastic driving piece and a solid connecting body fixed to the bottom of the elastic driving piece; the elastic driving piece has a cavity formed therein, and the cavity is connected to an external independent air source through an air hole 51 of an end fixing mechanism 5; the solid connecting body fixed to the bottom of the elastic driving piece connects the bottoms of the various deformation units of the elastic driving piece together; the deformation of the elastic driving piece under air pressure is limited by the solid connecting body, so that the air-driven bending piece 1 is bent under the action of air pressure; due to the material properties of the air-driven bending piece 1, the deformation of the air-driven bending piece 1 will disappear after the air pressure load is removed, and the air-driven bending piece 1 will restore to the original state;

[0083] Through the joint action of the air-driven bending piece 1, the deformation limiting structure 2, the connecting structure 3 and the variable stiffness mechanism 4, the pneumatic soft actuator is bent under the action of air pressure; under the action of positive pressure, the pneumatic soft actuator is bent to the side where the deformation limiting structure 2, the connecting structure 3 and the variable stiffness mechanism 4 are distributed; under the action of negative pressure, the bending direction is opposite.

[0084] The bending angle of the pneumatic soft actuator is related to the air pressure value of the compressed gas in the cavity of the air-driven bending piece 1, and the compressed gas is independently controlled by an external air pressure source; the bending angle of the pneumatic soft actuator is also related to the stiffness of the variable stiffness mechanism 4; when the equivalent density of the variable stiffness mechanism is low, the stiffness is small, the pneumatic soft actuator is more easily deformed, and the bending angle is larger; when the equivalent density of the variable stiffness mechanism is high, the stiffness is large, the pneumatic soft actuator is not easily deformed, and the bending angle is small;

[0085] The pneumatic soft actuator has the following advantages:

[0086] I. By selecting the variable stiffness mechanism 4 with different equivalent densities, the stiffness of the pneumatic soft actuator can be changed, and the variable stiffness design of the pneumatic soft actuator can be realized; when the pneumatic soft actuator needs flexible movement and lower load, the variable stiffness mechanism 4 with lower equivalent density is selected, and at this time, the pneumatic soft actuator body formed has lighter mass and is easily deformed; when the pneumatic soft actuator needs higher load capacity and larger output force, the variable stiffness mechanism 4 with higher equivalent density is selected, and at this time, the pneumatic soft actuator body formed has larger stiffness and higher load capacity; by selecting and installing the variable stiffness mechanism 4 with different equivalent densities, the stiffness of the pneumatic soft actuator can be flexibly controlled;

[0087] II. The connecting mechanism 3 on the present application is designed inspired by the mortise and tenon structure, and the connecting mechanism 3 can be reversibly disassembled and assembled;

[0088] Thirdly, the variable stiffness mechanism 4 with different stiffness is designed by changing the equivalent density of the variable stiffness mechanism 4; the stiffness of the variable stiffness mechanism changes with the change of the equivalent density; so that the application is suitable for different working environments;

[0089] Another aspect of the application also provides a variable stiffness soft robot, comprising the above-mentioned pneumatic soft actuator and the base 8; the plurality of pneumatic soft actuators are installed on the base 8.

[0090] In some embodiments, the number of the pneumatic soft actuators is three, and the three pneumatic soft actuators are arranged on the base 8 in a circumferential array around the central axis of the base 8; the gas source of the three pneumatic soft actuators on the soft robot comes from an external gas source, and the air pressure in the three pneumatic soft actuators is controlled by three independent gas sources respectively; by controlling the air pressure in the three pneumatic soft actuators respectively, the deformation effects of the three pneumatic soft actuators can be equal or not. Such flexible combination enriches the grasping effect of the soft robot.

[0091] Referring to FIG. 7, the first structure of the soft robot, the variable stiffness mechanism 4 on the three pneumatic soft actuators is installed on the base 8 in a posture facing the central axis of the base 8; under the action of positive pressure, the design can make the pneumatic soft actuator bend inward, and the bending direction is toward the central axis of the base 8, in this state, the three pneumatic soft actuators can realize the enveloping grasping effect from the outside to the inside; under the action of negative pressure, the bending direction is opposite.

[0092] Referring to FIG. 9, the second structure of the soft robot, the variable stiffness mechanism 4 on the three pneumatic soft actuators is installed on the base 8 in a posture away from the central axis of the base 8; under the action of positive pressure, the design can make the pneumatic soft actuator bend outward, and the bending direction is away from the central axis of the base 8, in this state, the three pneumatic soft actuators can realize the inside supporting grasping effect from the inside to the outside. Under the action of negative pressure, the bending direction is opposite.

[0093] The third structure of the soft robot, the variable stiffness mechanism 4 on the three pneumatic soft actuators is installed on the base 8 in a posture facing and / or away from the central axis of the base 8. Under the action of positive pressure, the design can make the pneumatic soft actuator bend inward and / or outward, and the bending direction is toward and / or away from the central axis of the base 8, in this state, it is more suitable for grasping irregular-shaped objects. Under the action of negative pressure, the bending direction is opposite.

[0094] Referring to FIG. 10, the base 8 is formed with a connecting portion and a plurality of supporting portions, the base 8 is connected with external equipment through the connecting portion, and the plurality of supporting portions are arranged around the connecting portion. The plurality of pneumatic soft actuators are respectively detachably mounted on the plurality of supporting portions of the base 8 through the plurality of connecting pieces 9, so as to realize the pose adjustment of the plurality of pneumatic soft actuators.

[0095] Referring to FIGS. 11 to 13, in some embodiments, the soft robot further comprises a plurality of connecting pieces 9 and end supports 10 corresponding to the number of pneumatic soft actuators respectively;

[0096] Specifically, the base 8 plays a role of connecting components of the soft robot and is connected with external equipment through the connecting portion. In the embodiment, the connecting portion is a round handle 81 and a square handle 83 with a second fixing hole 831 opened in the upper portion of the round handle 81, but is not limited thereto, and can be other different structures. The base 8 is distributed below with three supporting portions uniformly distributed at an interval of 120° in the circumferential direction. In the embodiment, the supporting portion is a support 82, and the structure of the supporting portion is not limited thereto, and can be other different structures. A rectangular slot 821 is opened in the middle of each support 82, and the air pipe on the independent air source can pass through the middle of the rectangular slot 821. A plurality of first fixing holes 822 are opened on both sides of each support 82 at equal intervals; through the first fixing holes 822 and the first connecting holes 92 opened on the connecting piece 9, the detachable fixing of the support 82 and the connecting piece 9 can be realized.

[0097] A through slot 91 is opened on the connecting piece 9, the support 82 on the base 8 passes through the middle of the through slot 91, and a first connecting hole 92 matched with the first fixing hole 822 on the support 82 is opened on both sides of the through slot 91, so as to realize the detachable fixing of the connecting piece 9 on the support 82 of the base 8. A rectangular hole 93 is opened on the top of the connecting piece 9, and a round hole 94 is opened in the middle of the connecting piece 9. In the working process of the soft robot, the air pipe providing the air source passes through the top rectangular hole 93 of the connecting piece 9, the rectangular slot 821 in the middle of the support 82 of the base 8, and the middle round hole 94 of the connecting piece 9, and is connected to the air hole 51 on the end fixing mechanism 5 to realize the communication of the air source and the pneumatic soft actuator. The connecting piece 9 is detachably fixed with the pneumatic soft actuator below. The second connecting hole 95 and the third connecting hole 96 are opened below the connecting piece 9, the third fixing hole 52 is opened on the first end fixing mechanism 5, the fourth fixing hole 61 is opened on the second end fixing mechanism 6, the third fixing hole 52 and the fourth fixing hole 61 are matched with the second connecting hole 95 on the connecting piece 9. The fifth fixing hole 71 is opened on the third end fixing mechanism 7. The fifth fixing hole 71 is matched with the third connecting hole 96 on the connecting piece 9. Through the detachable fixing of the third fixing hole 52, the fourth fixing hole 61 and the second connecting hole 95, and the detachable fixing of the fifth fixing hole 71 and the third connecting hole 96, the detachable fixing of the pneumatic soft actuator and the connecting piece 9 can be realized.

[0098] The fourth connecting hole 101 and the fifth connecting hole 102 are arranged on both sides of the end support 10, the fourth connecting hole 101 is detachably matched and fixed with the third fixing hole 52 and the fourth fixing hole 61, and the fifth connecting hole 102 is detachably matched and fixed with the fifth fixing hole 71, so as to realize detachable fixing of the pneumatic soft actuator and the end support 10.

[0099] The working principle of the soft robot is as follows:

[0100] After the soft robot is filled with the pressurized gas, the pneumatic soft actuator is bent under the action of the pressurized gas, and the bending angle is further increased with the increase of the gas pressure. By controlling the gas pressure of each actuator, the deformation of the soft robot is controlled, so that the soft robot completes the task of grabbing and the like. When facing loads of different weights, pneumatic soft actuators of different stiffnesses are selected and their gas pressures are controlled, so as to realize the grabbing of the soft robot to target objects of different weights.

[0101] The soft robot also has the following advantages:

[0102] The grabbing radius is adjustable, a plurality of pneumatic soft actuators are respectively installed on a plurality of supports 72 of the base 7 through a plurality of connecting pieces 8, and the plurality of connecting pieces 8 are respectively installed on the plurality of supports 72 of the base 7 in a detachable manner; when facing grabbing objects of different diameters, the positions of the connecting pieces 8 can be adjusted to adjust the grabbing radius of the soft robot, which enhances the grabbing capacity of the soft robot.

[0103] The grabbing effect is adjustable, the connecting piece 8 of the soft robot can be flexibly adjusted in the installation direction, and when the installation direction of the connecting piece 8 is adjusted, the grabbing effect of the pneumatic soft robot will change. According to the use scene, the installation direction of one or more connecting pieces 8 can be adjusted, so that the soft robot meets a plurality of different use scenes.

[0104] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Moreover, the technical solutions of each embodiment of the present application can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A modular variable-stiffness pneumatic soft actuator, characterized in that, The utility model relates to a kind of pneumatic soft actuators, comprising: Air-driven bending piece (1) is composed of elastic driving element and solid connection body fixed at the bottom of elastic driving element;The inside of elastic driving element is formed with cavity, and the cavity in the inside of elastic driving element on air-driven bending piece (1) is communicated with external independent gas source;The deformation of elastic driving element under gas pressure is limited by solid connection body, so that air-driven bending piece (1) is bent under the action of gas pressure; Deformation limiting member (2) is arranged on the bottom surface of air-driven bending piece (1), to limit the elongation of air-driven bending piece (1); Connecting mechanism (3) is arranged on the bottom surface of deformation limiting member (2); Variable stiffness mechanism (4) comprises a plurality of variable stiffness members, and the plurality of variable stiffness members are selectively installed at the bottom of connecting mechanism (3).

2. The pneumatic soft body effector of claim 1, wherein, It further comprises a first end fixing mechanism (5), and the first end fixing mechanism (5) comprises two first fixing parts. The two first fixing parts are respectively fixedly installed at two ends in the length direction of air-driven bending piece (1), and a gas hole (51) is formed in one of the first fixing parts, so as to communicate the gas hole (51) with the external independent gas source, thereby realizing the communication between the external independent gas source and the cavity in air-driven bending piece (1).

3. The pneumatic soft body effector of claim 2, wherein, The connecting mechanism (3) comprises: A first connecting member (31) is fixedly arranged on one side of the deformation limiting member (2); A second connecting member (32) is fixedly arranged on one side of the variable stiffness mechanism (4), and the second connecting member (32) is detachably installed on the first connecting member (31), so as to facilitate the disassembly of the variable stiffness mechanism.

4. The pneumatic soft body effector of claim 3, wherein, A plurality of recessed clamping grooves (311) are formed in the bottom surface of the first connecting member (31), and a plurality of convex clamping buckles (321) are formed in the top surface of the second connecting member (32) and are matched with the recessed clamping grooves (311); The plurality of convex clamping buckles (321) on the second connecting member (32) are respectively clamped in the plurality of recessed clamping grooves (311) of the first connecting member (31), so as to detachably install one of the variable stiffness members of the variable stiffness mechanism (4) on the first connecting member (31) at the bottom of air-driven bending piece (1) by the second connecting member (32) at the top.

5. The pneumatic soft body effector of claim 1, wherein, A plurality of first through holes are formed in at least part of the variable stiffness members of the variable stiffness mechanism (4), and the cross-sectional areas of the first through holes in the plurality of variable stiffness members gradually decrease until completely disappear, so that the equivalent densities of the plurality of variable stiffness members are different.

6. The pneumatic soft body effector of claim 1, wherein, The thickness of the deformation limiting member (2) is 0.05-2 mm, and the material of the deformation limiting member (2) is paper or glass fiber.

7. The pneumatic soft body effector of claim 1, wherein, The utility model further comprises a third end fixing mechanism (7), and the third end fixing mechanism (7) comprises two third fixing parts. The two third fixing parts are respectively fixedly installed at two ends in the length direction of the variable stiffness mechanism (4).

8. A variable-stiffness soft robotic device, comprising: The utility model comprises a plurality of pneumatic soft actuators according to any one of claims 1-7 and a base (8), and the plurality of pneumatic soft actuators are installed on the base (8).

9. The soft robotic body of claim 8, wherein, The number of the pneumatic soft actuators is three, and the three pneumatic soft actuators are arranged in a circle around the central axis of the base (8) on the base (8); the gas source of the three pneumatic soft actuators on the soft robot comes from an external gas source, and the gas pressures in the three pneumatic soft actuators are respectively controlled by three independent gas sources. The variable stiffness mechanism (4) on the three pneumatic soft actuators is installed on the base (8) in a posture facing the central axis of the base (8); Or, the variable stiffness mechanism (4) on the three pneumatic soft actuators is installed on the base (8) in a posture facing away from the central axis of the base (8); Or, the variable stiffness mechanism (4) on the three pneumatic soft actuators is installed on the base (8) in a posture facing and / or facing away from the central axis of the base (8).

10. The soft robotic body of claim 9, wherein, A plurality of connecting members (9) and end supports (10) corresponding to the number of pneumatic soft actuators are also included; The base (8) is formed with a connecting portion and a plurality of supporting portions, the base (8) is connected with external equipment through the connecting portion, the plurality of supporting portions are arranged around the connecting portion, and the plurality of pneumatic soft actuators are respectively detachably installed on the plurality of supporting portions of the base (8) through the plurality of connecting members (9), so as to realize the pose adjustment of the plurality of pneumatic soft actuators.

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