Single-plane motion flexible mechanical arm

Abstract

The invention provides a single-plane motion flexible mechanical arm which comprises a first folding structure fluid actuator, a second folding structure fluid actuator and a plane restraining mechanism for restraining motion of the first folding structure fluid actuator and the second folding structure fluid actuator in a first plane. The plane constraint mechanism is fixedly connected with the first folding structure fluid actuator and the second folding structure fluid actuator, and the ratio of the extension ratio m of the single-plane motion flexible mechanical arm to the extension ratio n of the first folding structure fluid actuator and the second folding structure fluid actuator is larger than 80%. According to the single-plane motion flexible mechanical arm, in the stretching or bending process, all the folding structure fluid actuators are located in the same plane all the time, and the problem that the shape of the single-plane motion flexible mechanical arm is unstable is solved; the working range capable of being covered by the single-plane motion flexible mechanical arm can be widened, and the moving operation comprehensive performance requirement of the single-plane motion flexible mechanical arm can be met.

Description

Technical Field

[0001] The present application belongs to the technical field of robotic arms, and more specifically, to a single-plane motion flexible robotic arm. Background Art

[0002] In common flexible robotic arm products, the single degree of freedom of rotation, bending or extension of the flexible robotic arm can be achieved by controlling the expansion and contraction of one or more complex-shaped airbags or one or more simple-shaped airbags in combination with rigid structural parts. Since the structural characteristics and processing precision of the flexible airbags used in existing flexible robotic arms determine the non-directionality of the expansion and contraction directions of the flexible airbags themselves, it is difficult to achieve precise control and operation of the flexible robotic arm. It is usually difficult to keep multiple flexible airbags in one plane, and there is a problem that the shape and motion state of the flexible robotic arm are unstable and cannot be precisely controlled and operated. In addition, the existing single-hinge connection structure robotic arm cannot achieve the dual degrees of freedom of expansion and contraction in the plane while maintaining stability.

[0003] When the flexible robotic arm in the existing technology is applied to operating scenarios such as drones and sweeping robots, comprehensive requirements are put forward for the volume, weight, energy consumption and operating range of the flexible robotic arm that are different from those of the traditional fixed-point operation robotic arm. That is, under the premise of ensuring its carrying capacity, the smaller the volume of the flexible robotic arm, the lighter the weight, the lower the energy consumption, and the larger the covered working space, the more conducive to mobile operations.

[0004] However, in the prior art, under the premise of a certain carrying capacity, a complete robotic arm system including control components and drive components cannot simultaneously meet the comprehensive requirements of small size, light weight, low energy consumption and large operating range.

[0005] In addition, controlling the expansion and contraction of a flexible airbag often requires a positive pressure pump or a negative pressure pump to cooperate with the opening and closing of the solenoid valve or the proportional valve. As an elastic part, the flexible airbag can work from a compressed state to a normal state, and then from a normal state to an expanded state; when driven by a positive pressure pump, the flexible airbag's stroke is from a normal state to an expanded state, and when driven by a negative pressure pump, the flexible airbag's stroke is from a normal state to a contracted state. Whether it is driven by positive pressure or negative pressure, the flexible airbag's telescopic characteristics cannot be fully utilized, resulting in a relatively small telescopic range of the flexible airbag and a small operating range of the flexible robotic arm. Summary of the invention

[0006] The purpose of the embodiments of the present application is to provide a single-plane motion flexible robotic arm to solve the technical problems existing in the prior art that the flexible robotic arm has an unstable shape and a small working range during operation.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present application is: to provide a single-plane motion flexible mechanical arm, comprising: a first folding structure fluid actuator, a second folding structure fluid actuator, and a plane constraint mechanism that constrains the motion of the first folding structure fluid actuator and the second folding structure fluid actuator within a first plane, the plane constraint mechanism being fixedly connected to the first folding structure fluid actuator and the second folding structure fluid actuator respectively;

[0008] The first folding structure fluid actuator and the second folding structure fluid actuator can shrink in length when in the first state, so that the single-plane motion flexible mechanical arm is shortened and accommodated in a narrow space; the first folding structure fluid actuator and the second folding structure fluid actuator can extend and / or shrink in length when in the second state, so that the single-plane motion flexible mechanical arm can achieve bending and / or telescopic movement in the first plane;

[0009] The expansion and contraction ratio of the single-plane motion flexible mechanical arm is defined as m, the expansion and contraction ratio of the first folding structure fluid actuator and the second folding structure fluid actuator is defined as n, and the ratio of m to n is greater than 80%.

[0010] Optionally, the first folding structure fluid actuator or the second folding structure fluid actuator comprises a flexible side wall, an opening and two end faces; the flexible side wall and the two end faces together form a cylindrical cavity having a central axis;

[0011] The flexible side wall is designed to include a multi-layer folding structure, each layer of the folding structure has a folding surface, the connection between two adjacent layers of folding surfaces forms a crease surface, and the angle between the adjacent folding surfaces and the crease surface is defined as an intrusion angle θ;

[0012] The first folding structure fluid actuator or the second folding structure fluid actuator has an initial intrusion angle θp in an initial state, and the intrusion angle θ changes between 0° and the initial intrusion angle θp during the compression or extension of the folding structure, wherein the initial intrusion angle θp satisfies 30°≤θp≤45°;

[0013] The folds formed at the connection of each folding surface of two adjacent folding structures are circles with different radii, the radius of the convex part of the first folding structure fluid actuator or the second folding structure fluid actuator in the radial direction is R, and the radius of the concave part is r, and the penetration depth coefficient a of the first folding structure fluid actuator or the second folding structure fluid actuator is defined as a=r / R, and 0.4≤a<0.6;

[0014] The structural coefficient σ of the folding surface satisfies 0.06≤σ≤0.15 and σ=cosθ(1+a) / (2cosθ-1+a);

[0015] It should be noted that a, R, r and their relationship are used to illustrate the relative relationship between the folding penetration depth and the cross-sectional size of the folding unit, and do not mean that the cross-section of the folding unit must be circular or entirely surrounded by arc edges.

[0016] The opening is arranged on the flexible side wall or the end face, and the opening is used to allow the driving fluid to enter and exit the cavity to change the internal and external pressure difference of the cavity and to compress or stretch the folding structure to drive the two end faces of the first folding structure fluid actuator or the second folding structure fluid actuator to be relatively close or far away; to shorten or lengthen the first folding structure fluid actuator or the second folding structure fluid actuator.

[0017] Optionally, the plane restraint mechanism includes a plane telescopic rotation assembly, a first fixed frame, and a second fixed frame;

[0018] The first fixing frame and the second fixing frame are both arranged perpendicular to the first plane, and a plurality of first fixing frames and second fixing frames are alternately arranged along the telescopic direction of the single-plane motion flexible mechanical arm; the first fixing frame and the second fixing frame are both provided with a connecting portion for connecting the first folding structure fluid actuator and the second folding structure fluid actuator; the plane telescopic rotation assembly is connected between adjacent first fixing frames and second fixing frames;

[0019] The plane telescopic rotation assembly comprises a first hinge, a second hinge and a telescopic assembly, wherein the plane telescopic rotation assembly is connected to the first fixing frame via the first hinge, and the plane telescopic rotation assembly is connected to the second fixing frame via the second hinge; the first hinge and the second hinge are connected via the telescopic assembly; the first hinge and the second hinge can approach or move away from each other when the single-plane motion flexible mechanical arm is telescoped and / or bent, and the first rotation axis of the first hinge and the second rotation axis of the second hinge are perpendicular to the first plane;

[0020] The telescopic assembly is arranged in a second plane, and the second plane is parallel to the first plane.

[0021] Optionally, the telescopic assembly includes a first structural member and a second structural member, and the first structural member and the second structural member are hinged by a third rotating shaft, so that the first structural member and the second structural member can rotate relative to each other in a second plane, and the first structural member is connected to the first fixed frame by a first hinge part; the second structural member is connected to the second fixed frame by a second hinge part.

[0022] As another optional technical solution, the telescopic assembly is a telescopic rod with two ends respectively hinged to the first hinge part and the second hinge part.

[0023] As another optional technical solution, the telescopic assembly is provided with a slide groove and / or a slide rail, and the first hinged portion and the second hinged portion are slidably connected to the slide groove and / or the slide rail.

[0024] Optionally, the first folded structure fluid actuator and the second folded structure fluid actuator are provided with a fixing ring that matches the shape of the connecting portion, and the Young's modulus of the material constituting the fixing ring is greater than the Young's modulus of the side wall material of the first folded structure fluid actuator and the second folded structure fluid actuator.

[0025] As another optional technical solution, the radial wall thickness of the fixing ring is greater than the radial wall thickness of the side walls of the first folding structure fluid actuator and the second folding structure fluid actuator.

[0026] Optionally, the fixing ring has a first mating portion and the connecting portion has a second mating portion, one of the first mating portion and the second mating portion has a first positioning portion protruding from the mating surface along the radial direction of the first folded structure fluid actuator or the second folded structure fluid actuator, and the other of the first mating portion and the second mating portion has a second positioning portion recessed from the mating surface along the radial direction of the first folded structure fluid actuator or the second folded structure fluid actuator, and the first positioning portion is embedded in the second positioning portion.

[0027] Optionally, the first folding structure fluid actuator or the second folding structure fluid actuator includes a plurality of folding modules connected in sequence along the axial direction, and the two ends of the folding module respectively have a third matching portion and a fourth matching portion of matching shapes, and one of the third matching portion and the fourth matching portion has a third positioning portion protruding from the mating surface along the axial direction of the first folding structure fluid actuator or the second folding structure fluid actuator, and the other of the third matching portion and the fourth matching portion has a fourth positioning portion recessed from the mating surface along the axial direction of the first folding structure fluid actuator or the second folding structure fluid actuator, and the third positioning portion is embedded in the fourth positioning portion for assembly.

[0028] Optionally, the first fixed frame and the second fixed frame have the same structure, and the first fixed frame or the second fixed frame includes a first mounting frame and a second mounting frame connected to each other, the first mounting frame is provided with a first mounting port, and the second mounting frame is provided with a second mounting port, and the first mounting port and the second mounting port together form an installation space for the first folding structure fluid actuator or the second folding structure fluid actuator.

[0029] Optionally, the telescopic assembly further includes an elastic member connected between the first hinge portion and the second hinge portion; the elastic member is used to provide force in the extension direction to help the flexible robotic arm return to a predetermined length.

[0030] Optionally, when the telescopic assembly includes a hinged first structural member and a second structural member, the elastic member is a torsion spring, the torsion spring is sleeved on the third rotating shaft, the first structural member and the second structural member are both provided with mounting grooves, and two ends of the torsion spring are respectively embedded in the mounting groove of the first structural member and the mounting groove of the second structural member;

[0031] When the pressure difference between the internal air pressure of the first folding structure fluid actuator, the internal air pressure of the second folding structure fluid actuator and the external air pressure is 0, the angle between the first structural member and the second structural member is α, and the angle between the two ends of the torsion spring in the natural state is λ, wherein λ=130°±10°, 0.55λ≤α≤0.75λ.

[0032] The beneficial effects of the single-plane motion flexible robotic arm provided by the present application are: compared with the prior art, the first folding structure fluid actuator and the second folding structure fluid actuator in the single-plane motion flexible robotic arm of the present application are fixedly connected to the plane constraint mechanism, so that the various folding structure fluid actuators of the single-plane motion flexible robotic arm are always in the same plane during the extension or bending process, avoiding the problem of unstable shape of the single-plane motion flexible robotic arm; the extension ratio m of the single-plane motion flexible robotic arm is greater than 80% of the extension ratio n of the first folding structure fluid actuator and the second folding structure fluid actuator, so as to meet the comprehensive performance requirements of the mobile operation of the single-plane motion flexible robotic arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0034] Figure 1 The structure diagram of the single-plane motion flexible mechanical arm provided in the embodiment of the present application applied to the sweeping robot Figure 1 ;

[0035] Figure 2 A schematic diagram of the structure of a planar telescopic rotation assembly provided in an embodiment of the present application;

[0036] Figure 3 A front view of a planar telescopic rotating assembly provided in an embodiment of the present application;

[0037] Figure 4 For along Figure 3 The cross-sectional structure diagram along the AA line;

[0038] Figure 5 A rear view of a single-plane motion flexible robotic arm provided in an embodiment of the present application;

[0039] Figure 6 A schematic diagram of the connection structure between the support frame and the planar telescopic rotating assembly provided in an embodiment of the present application;

[0040] Figure 7 for Figure 6 A partial top view of

[0041] Figure 8 A schematic structural diagram of a first folding structure fluid actuator provided in an embodiment of the present application;

[0042] Fig. 9 A front view of a folding module provided in an embodiment of the present application;

[0043] Fig.10 For along Fig. 9 The cross-sectional structure diagram of the middle BB line;

[0044] Fig.11 A schematic diagram of the structure of a second fixing frame provided in an embodiment of the present application;

[0045] Fig.12 A cross-sectional view of a second fixing frame provided in an embodiment of the present application;

[0046] Fig.13 is a cross-sectional structural diagram along the axis of the folded structure fluid actuator;

[0047] Fig.14 A rear view of the dust guide cover provided in the embodiment of the present application;

[0048] Fig.15 For along Fig.14 Cross-sectional structural diagram of the center CC line;

[0049] Fig.16 for Fig.15 D-direction view;

[0050] Fig.17 A pneumatic control schematic diagram provided for an embodiment of the present application;

[0051] Fig.18 A schematic diagram of a partial structure of a plane constraint mechanism provided in an embodiment of the present application;

[0052] Fig.19 A schematic diagram of the structure of a torsion spring provided in an embodiment of the present application;

[0053] Fig. 20 The structure diagram of the single-plane motion flexible mechanical arm provided in the embodiment of the present application applied to the sweeping robot Figure 2 ;

[0054] Fig.21 A schematic diagram of the structure of a fourth plane telescopic rotation assembly provided in an embodiment of the present application;

[0055] Fig. 22 The structure diagram of the single-plane motion flexible mechanical arm provided in the embodiment of the present application applied to the sweeping robot Figure 3 ;

[0056] Fig.23 A schematic diagram of the structure of a fifth plane telescopic rotation assembly provided in an embodiment of the present application;

[0057] Fig.24 A schematic diagram of the partial structure of a fifth plane telescopic rotation assembly provided in an embodiment of the present application;

[0058] Fig.25 Schematic diagram of the activity coverage range of the single-plane motion flexible robotic arm provided in an embodiment of the present application.

[0059] Among them, the reference numerals in the figure are:

[0060] 1a-first folding structure fluid actuator; 1b-second folding structure fluid actuator; 11-folding module; 111-third matching part; 112-fourth matching part; 12-fixing ring; 13-flexible side wall; 131-folding surface; 132-fold; 14-opening; 15-end surface;

[0061] 2-plane telescopic rotation assembly; 2a-first plane telescopic rotation assembly; 2b-second plane telescopic rotation assembly; 2c-third plane telescopic rotation assembly; 2d-fourth plane telescopic rotation assembly; 2e-fifth plane telescopic rotation assembly; 21-first structural member; 211-mounting groove; 212-angle limiting part; 22-second structural member; 23-elastic member; 24-third rotating shaft; 25-first hinge part; 26-second hinge part; 27-telescopic rod; 28-slide groove; 29-slide rail;

[0062] 3-first fixing frame; 31-first cover plate; 32-through hole A; 33-second matching portion A;

[0063] 4-second fixing frame; 41-first mounting frame; 411-first mounting port; 42-second mounting frame; 421-second mounting port; 43-positioning member; 44-through hole B; 45-connecting assembly; 46-second matching portion B; 47-second cover plate; 48-trachea connecting port;

[0064] 5-Roller assembly;

[0065] 6- Pump;

[0066] 7-valve parts;

[0067] 8-Dust suction pipe;

[0068] 9-dust guide cover; 91-flow guide curved surface; 92-dust suction port; 921-equal height section; 922-closed section; 923-flow guide inclined surface; 93-dust collection port; 94-counterweight part;

[0069] 10-Connection socket. DETAILED DESCRIPTION

[0070] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0071] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. 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.

[0072] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0073] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0074] Please also read Figure 1 , Figure 5 , Fig. 20 and Fig. 22 , the single-plane motion flexible robotic arm provided by the embodiment of the present application is now described. The single-plane motion flexible robotic arm includes a first folding structure fluid actuator 1a, a second folding structure fluid actuator 1b, and a plane constraint mechanism that constrains the motion of the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b within a first plane, and the plane constraint mechanism is fixedly connected to the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b, respectively, and is used to implement plane constraints on the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b, so as to avoid the problem of shape instability of the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b during operation.

[0075] See also Fig.25The first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b can shrink in length in the first state, so that the single-plane motion flexible mechanical arm is shortened and accommodated in a narrow space; please refer to Fig.25 When the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b are in the second state, they can extend and / or contract their lengths, so that the single-plane motion flexible robotic arm can achieve bending and / or telescopic motion within the first plane.

[0076] The telescopic ratio of the single-plane motion flexible manipulator is defined as m, the telescopic ratio of the first folding structure fluid actuator and the second folding structure fluid actuator is defined as n, and the ratio of m to n is greater than 80% to meet the comprehensive performance requirements of the mobile operation of the single-plane motion flexible manipulator. The telescopic ratio refers to the ratio of the length when extended to the length when contracted.

[0077] Compared with the prior art, the single-plane motion flexible robotic arm provided by the present application has a first folding structure fluid actuator and a second folding structure fluid actuator in the single-plane motion flexible robotic arm of the present application that are fixedly connected to a plane constraint mechanism, so that each folding structure fluid actuator of the single-plane motion flexible robotic arm is always in the same plane during the extension or bending process, thereby avoiding the problem of unstable shape of the single-plane motion flexible robotic arm; the maximum extension length of the first folding structure fluid actuator and the second folding structure fluid actuator is more than 2.5 times the minimum contraction length, which can greatly improve the working range that the single-plane motion flexible robotic arm can cover, such as Fig.25 As shown, it can meet the comprehensive performance requirements of mobile operations of single-plane motion flexible robotic arms.

[0078] The shapes of the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b can be selected according to needs. In some embodiments of the present application, since the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b have the same structure, both are bellows-shaped flexible airbag structures, the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b are referred to as folding structure fluid actuators below.

[0079] In another embodiment of the present application, please refer to Figures 3 to 5 The first folding structure fluid actuator 1a or the second folding structure fluid actuator 1b comprises a flexible side wall 13, an opening 14 and two end surfaces 15; the flexible side wall 13 and the two end surfaces 15 together form a cylindrical cavity having a central axis;

[0080] See also Fig. 9 and Fig.10The flexible side wall 13 is designed to include a multi-layer folding structure, and the cross-sectional contour line shape of the multi-layer folding structure in the axial direction is a cos curve shape, which can reduce the stress / strain concentration of the first folding structure fluid actuator 1a or the second folding structure fluid actuator 1b during the folding or stretching process, especially under the extreme state (compressed to the shortest and stretched to the longest), optimize the working conditions of the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b, reduce the requirements for the materials of the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b under certain loads and strokes, and extend the service life of the folding structure fluid actuator.

[0081] See also Fig. 9 and Fig.10 Each layer of the folding structure has a folding surface 131, and the connection between two adjacent layers of folding surfaces 131 forms a crease surface, and the angle between the adjacent folding surfaces 131 and the crease surface is defined as an intrusion angle θ;

[0082] The first folding structure fluid actuator 1a or the second folding structure fluid actuator 1b has an initial intrusion angle θp in the initial state, and the intrusion angle θ varies between 0° and the initial intrusion angle θp during compression or extension of the folding structure, wherein the initial intrusion angle θp satisfies 30°≤θp≤45°; by setting a favorable initial intrusion angle range, the folding structure can be advantageously caused to have a smaller strain during the deformation process, or the strain distribution can be made more uniform.

[0083] As a preferred embodiment of the present application, the range of the initial intrusion angle θp is 38°≤θp≤42°.

[0084] See also Fig.10 The fold 132 formed at the connection of each folding surface 131 of the adjacent two-layer folding structure is a circle with different radii. The radius of the circle at the protrusion along the radial direction of the first folding structure fluid actuator 1a or the second folding structure fluid actuator 1b is R, and the radius of the circle at the recess is r. The penetration depth coefficient a of the first folding structure fluid actuator 1a or the second folding structure fluid actuator 1b is defined as a=r / R, and 0.4≤a<0.6; since the folding structure fluid actuator has the characteristic of small strain as a flexible robotic arm muscle, the penetration depth coefficient a can be basically a constant during the deformation process of the folding structure fluid actuator.

[0085] When designing the folding structure, the structural coefficient σ of the folding surface 131 satisfies 0.06≤σ≤0.15 and σ=cosθ(1+a) / (2cosθ-1+a).

[0086] As a preferred embodiment of the present application, the range of the penetration depth coefficient a is 0.4≤a<0.55.

[0087] See also Fig.10 The opening 14 is arranged on the flexible side wall 13 or the end face 15, and the opening 14 is used to allow the driving fluid to enter and exit the cavity to change the internal and external pressure difference of the cavity and to compress or stretch the folding structure to drive the two end faces of the folding structure fluid actuator to be relatively close or far away; to shorten or lengthen the folding structure fluid actuator.

[0088] As a preferred embodiment of this application, please refer to Fig.10 The opening 14 is arranged on the end surface 15, the driving fluid is gas, and each folding structure fluid actuator is extended and retracted under the action of the negative pressure pump, thereby making the single-plane motion flexible robotic arm extend and retract or bend.

[0089] In another embodiment of the present application, please refer to Figure 1 , Figure 6 , Fig. 20 and Fig. 22 , the plane constraint mechanism includes a plane telescopic rotation component 2, a first fixed frame 3 and a second fixed frame 4;

[0090] The first fixed frame 3 and the second fixed frame 4 are both arranged perpendicular to the first plane, and multiple first fixed frames 3 and second fixed frames 4 are alternately arranged along the telescopic direction of the single-plane motion flexible robotic arm; in some embodiments of the present application, the first fixed frame 3 and the second fixed frame 4 have the same structure, and the first fixed frame 3 and the second fixed frame 4 are both provided with a connecting portion for connecting the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b; the plane telescopic rotation assembly 2 is connected between adjacent first fixed frames 3 and second fixed frames 4.

[0091] In another embodiment of the present application, the connecting portion has a dimension less than 2 times the wall thickness of the folded structure fluid actuator in the axial direction of the corresponding position of the first folded structure fluid actuator 1a or the second folded structure fluid actuator 1b connected thereto, and extends along the outer peripheral contour of the fluid actuator in the plane direction perpendicular to the axis of the first folded structure fluid actuator connected thereto. Under the condition that the connection strength of the connecting portion is met, the connecting portion can be a full circle ring, a semicircular ring or other connecting structure extending along the outer peripheral contour of the folded structure fluid actuator.

[0092] As a preferred embodiment of the present application, the connecting portion is a full-circle ring structure, and the outer peripheral surface of the folded structure fluid actuator is arranged in contact with the inner peripheral surface of the connecting portion, such as Fig.11 and Fig.13 shown.

[0093] In another embodiment of the present application, please refer to Figure 1 , Figure 8 , Fig.11 and Fig.13The first folded structure fluid actuator 1a and the second folded structure fluid actuator 1b are provided with a fixing ring 12 which matches the shape of the connecting part. The Young's modulus of the material constituting the fixing ring 12 is greater than the Young's modulus of the side wall material of the first folded structure fluid actuator 1a and the second folded structure fluid actuator 1b, that is, the Young's modulus of the fixing ring 12 is greater than the Young's modulus of the flexible side wall 13, which can enhance the structural strength of the fixing ring 12 and meet the fixed matching requirements with the connecting part.

[0094] In another embodiment of the present application, the radial wall thickness of the fixing ring 12 is greater than the radial wall thickness of the side walls of the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b, that is, the radial thickness of the fixing ring 12 is greater than the radial thickness of the flexible side wall 13, which can enhance the structural strength of the fixing ring 12 and meet the fixed matching requirements with the connecting part.

[0095] When manufacturing the fixing ring 12 , a material with higher strength or a larger radial thickness should be used as much as possible to meet the structural strength requirement of the fixing ring 12 .

[0096] In another embodiment of the present application, along the length direction of the folded structure fluid actuator, the folded structure fluid actuator has at least two fixing rings 12, and the fixing rings 12 are integrally formed with the folded structure fluid actuator, which can simplify the preparation process of the folded structure fluid actuator.

[0097] In another embodiment of the present application, please refer to Fig.13 The fixing ring 12 has a first matching portion, and the connecting portion has a second matching portion. One of the first matching portion and the second matching portion has a first positioning portion protruding from the matching surface along the radial direction of the folding structure fluid actuator, and the other of the first matching portion and the second matching portion has a second positioning portion recessed from the matching surface along the radial direction of the folding structure fluid actuator. The first positioning portion is embedded in the second positioning portion to achieve a limited connection between the fixing ring 12 and the connecting portion to prevent the fixing ring 12 from falling off the connecting portion.

[0098] As a preferred embodiment of the present application, the connecting portion of the first fixing frame 3 has a second matching portion A33, and the connecting portion of the second fixing frame 4 has a second matching portion B46. The second matching portion A33 and the second matching portion B46 have the same structure, which is conducive to simplifying the types of parts production.

[0099] In another embodiment of the present application, see Figure 8 , Fig. 9 , Fig.10 and Fig.13The first folding structure fluid actuator 1a or the second folding structure fluid actuator 1b comprises a plurality of folding modules 11 connected in sequence along the axial direction, and the two ends of the folding module 11 respectively have a third matching portion 111 and a fourth matching portion 112 of matching shapes, and one of the third matching portion 111 and the fourth matching portion 112 has a third positioning portion protruding from the matching surface along the axial direction of the folding structure fluid actuator, and the other of the third matching portion 111 and the fourth matching portion 112 has a fourth positioning portion recessed from the matching surface along the axial direction of the folding structure fluid actuator, and the third positioning portion is embedded in the fourth positioning portion for assembly. The folding structure fluid actuator is obtained by connecting a plurality of folding modules 11 with the same structure, which simplifies the BOM table and facilitates product design and production.

[0100] In another embodiment of the present application, the first positioning portion is arranged on the connecting portion, and the second positioning portion is arranged on the fixing ring 12; the folding module 11 is spliced ​​at the recess of the second positioning portion, which can reduce the number of small grooves that are difficult to process on a single workpiece and reduce the processing difficulty.

[0101] In another embodiment of the present application, please refer to Figure 6 , Fig.11 , Fig.12 and Fig.13 The first fixing frame 3 and the second fixing frame 4 have the same structure. The second fixing frame 4 is taken as an example for structural description. The second fixing frame 4 includes a first mounting frame 41 and a second mounting frame 42 connected to each other. The first mounting frame 41 is provided with a first mounting port 411, and the second mounting frame 42 is provided with a second mounting port 421. The first mounting port 411 and the second mounting port 421 together form an installation space for the folding structure fluid actuator, and the connecting portion is arranged inside the installation space.

[0102] In another embodiment of the present application, please refer to Fig.12 The first mounting frame 41 and the second mounting frame 42 are detachably connected via a connecting assembly 45, so that the folding structure fluid actuator can be easily placed in the installation space of the first fixing frame 3 and the second fixing frame 4 for installation.

[0103] In another embodiment of the present application, the first fixing frame 3 or the second fixing frame 4 further includes a positioning member 43, which is connected to the first mounting frame 41 and the second mounting frame 42 respectively to ensure the relative positioning accuracy between the first mounting frame 41 and the second mounting frame 42.

[0104] As a preferred embodiment of the present application, the first mounting bracket 41 and the second mounting bracket 42 are centrally symmetrical parts of the same shape, which can simplify the BOM (Bill of Material) table and facilitate product design and production.

[0105] In another embodiment of the present application, the first folding structure fluid actuator 1a has the same structure as the second folding structure fluid actuator 1b, the opening 14 is arranged on the end surface 15, and the first cover plate 31 and the second cover plate 47 are respectively arranged at both ends of the first folding structure fluid actuator 1a or the second folding structure fluid actuator 1b; an air pipe connecting port 48 is provided on the first cover plate 31 or the second cover plate 47, and is connected to the negative pressure pump through the air pipe connecting port 48 to realize the driving of the folding structure fluid actuator.

[0106] In another embodiment of the present application, the first cover plate 31 is disposed on the first fixing frame 3 or the second fixing frame 4 at one end of the folding structure fluid actuator, and the second cover plate 47 is disposed on the first fixing frame 3 or the second fixing frame 4 at the other end of the folding structure fluid actuator.

[0107] As a preferred embodiment of this application, please refer to Figure 6 The first cover plate 31 is disposed on the first fixing frame 3 at one end of the folding structure fluid actuator, and the second cover plate 47 is disposed on the second fixing frame 4 at the other end of the folding structure fluid actuator.

[0108] In another embodiment of the present application, please refer to the figure, the plane telescopic rotation assembly 2 includes a first hinge 25, a second hinge 26 and a telescopic assembly, the plane telescopic rotation assembly 2 is connected to the first fixing frame 3 through the first hinge 25, and the plane telescopic rotation assembly 2 is connected to the second fixing frame 4 through the second hinge 26; the first hinge 25 and the second hinge 26 are connected through the telescopic assembly; the first hinge 25 and the second hinge 26 can be close to or away from each other when the single-plane motion flexible mechanical arm is telescoped and / or bent, and the first rotation axis of the first hinge 25 and the second rotation axis of the second hinge 26 are perpendicular to the first plane;

[0109] The telescopic assembly is arranged in a second plane, and the second plane is parallel to the first plane, so that the multiple folding structure fluid actuators always telescope or bend in the first plane under the constraint of the plane constraint mechanism.

[0110] In another embodiment of the present application, please refer to Figure 2 , Figure 3 , Figure 4 and Figure 6 The telescopic assembly includes a first structural member 21 and a second structural member 22. The first structural member 21 and the second structural member 22 are hinged via a third rotating shaft 24, so that the first structural member 21 and the second structural member 22 can rotate relative to each other in a second plane. The first structural member 21 is connected to the first fixed frame 3 via a first hinge portion 25; the second structural member 22 is connected to the second fixed frame 4 via a second hinge portion 26.

[0111] As a preferred embodiment of the present application, the first hinged portion 25 and the first structural member 21 are integrated into one structure, and the second hinged portion 26 and the second structural member 22 are integrated into one structure, so that the telescopic assembly is compact and easy to manufacture.

[0112] In another embodiment of the present application, please refer to Fig. 20 and Fig.21 The telescopic component is a telescopic rod 27 connected to the first hinge part 25 and the second hinge part 26 at both ends respectively; when the single-plane motion flexible robotic arm is telescopic, the telescopic rods of the two fourth-plane telescopic rotation components 2d connected to the same first fixed frame 3 and the second fixed frame 4 have the same degree of telescopic extension; when the single-plane motion flexible robotic arm is bent, the telescopic rods of the two fourth-plane telescopic rotation components 2d connected to the same first fixed frame 3 and the second fixed frame 4 have different degrees of telescopic extension.

[0113] In another embodiment of the present application, please refer to Fig. 22 , Fig.23 and Fig.24 The telescopic assembly has a slide groove 28 and / or a slide rail 29 , and the first hinge part 25 and the second hinge part 26 are slidably connected to the slide groove 28 and / or the slide rail 29 .

[0114] As a preferred embodiment of the present application, the telescopic assembly of the fifth plane telescopic rotation assembly 2e includes a first slider and a second slider, the first slider has two sliding grooves 28, which are respectively used to slide with the first hinge part 25 and the second slider, the top of the second slider has a slide rail 29 for cooperating with the first slider, and the bottom of the second slider has a sliding groove 28 for cooperating with the second hinge part 26. When the first fixed frame 3 and the second fixed frame 4 are close to or away from each other, the length of the telescopic assembly is changed by the relative sliding between the components.

[0115] In another embodiment of the present application, please refer to Figure 4 The telescopic assembly also includes an elastic member 23, which is connected between the first hinge portion 25 and the second hinge portion 26; the elastic member 23 is used to provide force in the extension direction to help the flexible robotic arm return to a predetermined length.

[0116] In another embodiment of the present application, please refer to Figure 4 and Fig.19 In the case where the telescopic assembly includes a hinged first structure member 21 and a second structure member 22, the elastic member 23 is a torsion spring, and the torsion spring is sleeved on the third rotating shaft 24. The first structure member 21 and the second structure member 22 are both provided with mounting grooves 211, and the two ends of the torsion spring are respectively embedded in the mounting grooves 211 of the first structure member 21 and the mounting grooves 211 of the second structure member 22.

[0117] When the pressure difference between the internal air pressure and the external air pressure of the folding structure fluid actuator is 0, the angle between the first structural member 21 and the second structural member 22 is α, and the angle between the two ends of the torsion spring in the natural state is λ, wherein λ=130°±10°, 0.55λ≤α≤0.75λ, so that the torsion spring is in a compressed state when the pressure difference between the internal air pressure and the external air pressure of the folding structure fluid actuator is 0. In the absence of negative pressure drive, the folding structure fluid actuator will stretch under the action of the torsion spring, thereby increasing the telescopic ratio of the folding structure fluid actuator and expanding the working range that the single-plane motion flexible robotic arm can cover.

[0118] In another embodiment of the present application, please refer to Figure 1 , Figure 6 , Figure 7 and Fig.18 , when the telescopic assembly includes a hinged first structure member 21 and a second structure member 22, the first end of the first structure member 21 is hinged to the first end of the second structure member 22 through a third rotating shaft 24 to form a V-shaped structure;

[0119] The second end of the first structural member 21 is hinged to the first fixing frame 3 via a first hinged portion 25, and the second end of the second structural member 22 is hinged to the second fixing frame 4 via a second hinged portion 26;

[0120] The axis of the single-plane motion flexible manipulator is defined as b. In the same plane telescopic rotation assembly 2, the first rotation axis and the second rotation axis are located on the same side of b, and the third rotation axis 24 is located on the opposite side of the first rotation axis and the second rotation axis;

[0121] See also Figure 7 On both sides of the first plane, the first fixed frame 3 and the second fixed frame 4 are connected by two relatively arranged first plane telescopic rotating components 2a and second plane telescopic rotating components 2b. When the internal air pressure of each folding structure fluid actuator is the same, the projection positions of the third rotating shafts 24 of the two relatively arranged plane telescopic rotating components on the first plane are c and c' respectively, and the projection of the axis b of the single-plane motion flexible robotic arm on the first plane is b', and c and c' are symmetrically arranged about b'; on the same side of the first plane, adjacent first plane telescopic rotating components 2a and third plane telescopic rotating components 2c are staggered. When the internal air pressure of each folding structure fluid actuator is the same, the projection positions of the third rotating shafts 24 of the two adjacently arranged plane telescopic rotating components on the first plane are c and d respectively, and c and d are respectively located on both sides of b', and the first fixed frame 3 and the second fixed frame 4 can be evenly connected through the plane telescopic rotating component 2.

[0122] In another embodiment of the present application, please refer to Figure 5The projection position of the first rotating axis in the first hinge part 25 or the second rotating axis in the second hinge part 26 on the first plane is e, and the projection position of the second rotating axis in the second hinge part 26 on the first plane is f. The distance L from e or f to b' is configured to satisfy the following relationship: L≥1 / 6B, B is the width of the single-plane motion flexible robotic arm, which can make the angle between the first structural member 21 or the second structural member 22 and the adjacent fixed frame as small as possible in the retracted state, so as to reduce the minimum length of the single-plane motion flexible robotic arm.

[0123] In another embodiment of the present application, please refer to Fig.18 The first structural member 21 and the second structural member 22 have the same length, and the length D is configured to satisfy the following relationship: D≤2 / 3B, which can avoid the first structural member 21 and the second structural member 22 from interfering with other components when the single-plane motion flexible robotic arm contracts.

[0124] In another embodiment of the present application, please refer to Figure 2 , Figure 3 and Figure 4 The first structural member 21 and the second structural member 22 are both provided with an angle limiting portion 212. This can avoid extrusion interference between components, optimize the working condition of the telescopic assembly, and extend the service life of the telescopic assembly.

[0125] In another embodiment of the present application, a roller assembly 5 is provided on both the first fixing frame 3 and the second fixing frame 4. The roller assembly 5 is in contact with the working surface, thereby reducing the friction between the single-plane motion flexible robot arm and the working surface, thereby optimizing the working condition, reducing power consumption, and extending the service life.

[0126] In another embodiment of the present application, please refer to Fig.17 The single-plane motion flexible mechanical arm also includes a pump 6 and a valve 7. The first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b are connected to the pump 6 through independent drive branches, respectively. The first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b are connected to the atmosphere through pressure relief branches, respectively. The drive branch and the pressure relief branch are both provided with valves 7. The telescopic rotation action in a single plane that can only be achieved by a more complex system in the prior art is realized by a simple drive device and actuator, which has the effects of reducing weight and compressing volume, reducing power consumption, simplifying control logic, etc., and at the same time reduces the software and hardware requirements of the control part, and has obvious advantages in the subdivided field of mobile operations.

[0127] As a preferred embodiment of the present application, the pump 6 is a negative pressure pump, the valve element 7 is a solenoid valve, and a barometer is also provided in the drive branch for real-time detection of the air pressure.

[0128] See also Figure 1 , Fig.14, Fig.15 , Fig.16 , Fig. 20 and Fig. 22 The present application also provides a sweeping robot, including the single-plane motion flexible robotic arm in the above-mentioned embodiment, the sweeping robot also includes a vacuum cleaner body, a vacuum tube 8, a dust hood 9 and a connecting seat 10, the connecting seat 10 is connected between the second fixed frame 4 located at one end of the single-plane motion flexible robotic arm and the vacuum cleaner body; the axis of the vacuum tube 8 is parallel to the axis of the first folding structure fluid actuator 1a or the second folding structure fluid actuator 1b, the first folding structure fluid actuator 1a and the second folding structure fluid actuator 1b are symmetrically arranged about the vacuum tube 8; the first fixed frame 3 is provided with a through hole A32 for the vacuum tube 8 to pass through, the second fixed frame 4 is provided with a through hole B44 for the vacuum tube 8 to pass through, the first end of the vacuum tube 8 is connected to the dust hood 9, and the second end of the vacuum tube 8 is connected to the vacuum cleaner body; it is used to transmit the debris and dust collected by the dust hood 9 to the dust collecting component of the vacuum cleaner body.

[0129] See also Fig.14 , Fig.15 and Fig.16 The dust guide hood 9 includes a guide curved surface 91, a dust suction port 92 and a dust collecting port 93. The dust suction port 92 and the dust collecting port 93 are smoothly connected through the guide curved surface 91, which reduces unnecessary turbulence during dust suction and forms a smoother flow path, so that the airflow formed by the suction can better act on the sucked object instead of being dissipated in the corners and bends inside the flow path.

[0130] When in working state, the angle between the dust suction port 92 and the first plane is 0° to 45°, so as to facilitate the suction of debris and dust on the working surface;

[0131] See also Fig.16 The dust suction port 92 includes an equal height section 921 and a closed section 922. The two closed sections 922 are connected to both sides of the equal height section 921. In the width direction of the dust suction port 92, the height of the closed section 922 is gradually reduced from the center to the end of the dust suction port 92.

[0132] As a preferred embodiment of the present application, the contour shape of the closed section 922 is semicircular, which can reduce the airflow resistance at the corners of the suction port 92.

[0133] The edge of the dust suction port has a guide slope 923 , and the guide slope 923 is smoothly connected to the guide curved surface 91 , so as to facilitate debris and dust to enter the guide curved surface 91 and the dust collection port 93 .

[0134] In another embodiment of the present application, please refer to Fig.14A counterweight portion 94 is provided on the dust guide cover 9; the number of the counterweight portion 94 is one or more, and one or more counterweight portions 94 are symmetrically arranged about the central axis of the dust guide cover 9, which can prevent the dust guide cover 9 from tilting up during dust collection and affecting the working effect of the sweeping robot.

[0135] The present application also provides a flexible manipulator, which includes the single-plane motion flexible manipulator arm described in the above embodiment. One end of the single-plane motion flexible manipulator arm is connected to an actuator, and can be applied to equipment such as drones. The single-plane motion flexible manipulator arm cooperates with the actuator to perform operations.

[0136] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A single-plane motion flexible robotic arm, characterized by: It comprises a first folding structure fluid actuator, a second folding structure fluid actuator and a plane constraint mechanism for constraining the movement of the first folding structure fluid actuator and the second folding structure fluid actuator within a first plane, wherein the plane constraint mechanism is fixedly connected to the first folding structure fluid actuator and the second folding structure fluid actuator respectively; The first folding structure fluid actuator and the second folding structure fluid actuator can shrink in length when in the first state, so that the single-plane motion flexible mechanical arm is shortened and accommodated in a narrow space; The first folding structure fluid actuator and the second folding structure fluid actuator can extend and / or contract their lengths when in the second state, so that the single-plane motion flexible mechanical arm can achieve bending and / or telescopic motion within the first plane; The expansion and contraction ratio of the single-plane motion flexible mechanical arm is defined as m, the expansion and contraction ratio of the first folding structure fluid actuator and the second folding structure fluid actuator is defined as n, and the ratio of m to n is greater than 80%.

2. The single-plane motion flexible robotic arm according to claim 1, characterized in that: The first folding structure fluid actuator or the second folding structure fluid actuator comprises a flexible side wall, an opening and two end faces; the flexible side wall and the two end faces together form a cylindrical cavity having a central axis; The flexible side wall is designed to include a multi-layer folding structure, each layer of the folding structure has a folding surface, the connection between two adjacent layers of folding surfaces forms a crease surface, and the angle between the adjacent folding surfaces and the crease surface is defined as an intrusion angle θ; The first folding structure fluid actuator or the second folding structure fluid actuator has an initial intrusion angle θp in an initial state, and the intrusion angle θ varies between 0° and the initial intrusion angle θp during compression or extension of the folding structure, wherein the initial intrusion angle θp satisfies 30°≤θp≤45°; The folds formed at the connection of each folding surface of two adjacent folding structures are circles with different radii, the radius of the convex part of the first folding structure fluid actuator or the second folding structure fluid actuator in the radial direction is R, and the radius of the concave part is r, and the penetration depth coefficient a of the first folding structure fluid actuator or the second folding structure fluid actuator is defined as a=r / R, and 0.4≤a<0.6; The structural coefficient σ of the folding surface satisfies 0.06≤σ≤0.15 and σ=cosθ(1+a) / (2cosθ-1+a); The opening is arranged on the flexible side wall or on the end face, and the opening is used to allow the driving fluid to enter and exit the cavity to change the internal and external pressure difference of the cavity and to compress or stretch the folding structure to drive the two end faces of the first folding structure fluid actuator or the second folding structure fluid actuator to be relatively close or far away; to shorten or lengthen the first folding structure fluid actuator or the second folding structure fluid actuator.

3. The single-plane motion flexible robotic arm according to claim 1, characterized in that: The plane restraint mechanism comprises a plane telescopic rotation assembly, a first fixing frame and a second fixing frame; The first fixing frame and the second fixing frame are both arranged perpendicular to the first plane, and a plurality of the first fixing frames and the second fixing frames are alternately arranged along the telescopic direction of the single-plane motion flexible mechanical arm; the first fixing frame and the second fixing frame are both provided with a connecting portion for connecting the first folding structure fluid actuator and the second folding structure fluid actuator; the plane telescopic rotation assembly is connected between adjacent first fixing frames and second fixing frames; The plane telescopic rotation assembly includes a first hinge, a second hinge and a telescopic assembly, the plane telescopic rotation assembly is connected to the first fixed frame through the first hinge, and the plane telescopic rotation assembly is connected to the second fixed frame through the second hinge; the first hinge and the second hinge are connected through the telescopic assembly; the first hinge and the second hinge can approach or move away from each other when the single-plane motion flexible mechanical arm is telescoped and / or bent, and the first rotation axis of the first hinge and the second rotation axis of the second hinge are perpendicular to the first plane; The telescopic assembly is arranged in a second plane, and the second plane is parallel to the first plane.

4. The single-plane motion flexible robotic arm according to claim 3, characterized in that: The telescopic assembly includes a first structural member and a second structural member, the first structural member and the second structural member are hinged via a third rotating shaft, so that the first structural member and the second structural member can rotate relative to each other in a second plane, the first structural member is connected to the first fixing frame via the first hinged portion; the second structural member is connected to the second fixing frame via the second hinged portion; Alternatively, the telescopic assembly is a telescopic rod with two ends respectively connected to the first hinged portion and the second hinged portion; Alternatively, the telescopic assembly has a slide groove and / or a slide rail, and the first hinged portion and the second hinged portion are slidably connected to the slide groove and / or the slide rail.

5. The single-plane motion flexible robotic arm according to claim 3, characterized in that: The first folding structure fluid actuator and the second folding structure fluid actuator are provided with a fixing ring that matches the shape of the connecting portion, and the Young's modulus of the material constituting the fixing ring is greater than the Young's modulus of the side wall material of the first folding structure fluid actuator and the second folding structure fluid actuator; Alternatively, the radial wall thickness of the fixing ring is greater than the radial wall thickness of the side walls of the first folding structure fluid actuator and the second folding structure fluid actuator.

6. The single-plane motion flexible robotic arm according to claim 5, characterized in that: The fixing ring has a first mating portion, and the connecting portion has a second mating portion. One of the first mating portion and the second mating portion has a first positioning portion protruding from the mating surface along the radial direction of the first folding structure fluid actuator or the second folding structure fluid actuator, and the other of the first mating portion and the second mating portion has a second positioning portion recessed from the mating surface along the radial direction of the first folding structure fluid actuator or the second folding structure fluid actuator, and the first positioning portion is embedded in the second positioning portion.

7. The single-plane motion flexible robotic arm according to claim 1, characterized in that: The first folding structure fluid actuator or the second folding structure fluid actuator includes a plurality of folding modules connected in sequence along the axial direction, and the two ends of the folding module respectively have a third matching portion and a fourth matching portion with matching shapes, and one of the third matching portion and the fourth matching portion has a third positioning portion protruding from the matching surface along the axial direction of the first folding structure fluid actuator or the second folding structure fluid actuator, and the other of the third matching portion and the fourth matching portion has a fourth positioning portion recessed from the matching surface along the axial direction of the first folding structure fluid actuator or the second folding structure fluid actuator, and the third positioning portion is embedded in the fourth positioning portion for assembly.

8. The single-plane motion flexible robotic arm according to claim 7, characterized in that: The first fixing frame and the second fixing frame have the same structure. The first fixing frame or the second fixing frame includes a first mounting frame and a second mounting frame connected to each other. The first mounting frame is provided with a first mounting port, and the second mounting frame is provided with a second mounting port. The first mounting port and the second mounting port together form an installation space for the first folding structure fluid actuator or the second folding structure fluid actuator.

9. The single-plane motion flexible mechanical arm according to claim 4, characterized in that: The telescopic assembly also includes an elastic member connected between the first hinge part and the second hinge part; the elastic member is used to provide force in the extension direction to help the flexible robotic arm return to a predetermined length.

10. The single-plane motion flexible mechanical arm according to claim 9, characterized in that: When the telescopic assembly includes a hinged first structural member and a second structural member, the elastic member is a torsion spring, the torsion spring is sleeved on the third rotating shaft, the first structural member and the second structural member are both provided with mounting grooves, and the two ends of the torsion spring are respectively embedded in the mounting groove of the first structural member and the mounting groove of the second structural member; When the pressure difference between the internal air pressure of the first folding structure fluid actuator, the internal air pressure of the second folding structure fluid actuator and the external air pressure is 0, the angle between the first structural member and the second structural member is α, and the angle between the two ends of the torsion spring in the natural state is λ, wherein λ=130°±10°, 0.55λ≤α≤0.75λ.

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