Flexible variable-stiffness humanoid mechanical arm with variable fulcrum

Abstract

The invention discloses a variable-fulcrum flexible variable-stiffness humanoid mechanical arm which comprises a shoulder joint series connection module, a pivot joint series connection module, a pivot joint series connection module, a pivot joint series connection module and a pivot joint series connection module which are connected in sequence, the elbow joint driving module comprises a fourth driving unit and a connecting rod system; the elbow joint elastic input module comprises a guide rail assembly, an elastic assembly and a fixing assembly. The elastic assembly comprises an optical shaft sleeved with a linear bearing and a spring. The guide rail assembly comprises a guide rail, a sliding block assembly and a guide rail rotating shaft. One end of the guide rail is connected with the linear bearing through the sliding block assembly, and the other end is connected to the fixing assembly through the guide rail rotating shaft; the fixing assembly is connected to the connecting rod system and used for bearing power of the connecting rod system. An elbow joint variable stiffness module; and a terminal interaction module. The mechanical arm can achieve flexible variable-stiffness actions with variable fulcrums, provides a new thought for humanoid design, and has a great application prospect.

Description

Technical Field

[0001] The invention provides a flexible and variable-rigidity humanoid mechanical arm with variable fulcrums, belongs to the technical field of robots, and particularly relates to a humanoid mechanical arm. Background Art

[0002] In recent years, with the continuous development of robotics technology, humanoid robotic arms have received more and more attention in the fields of research and application. Compared with traditional industrial robotic arms, humanoid robotic arms have greater potential in application scenarios such as human-computer interaction because of their characteristics that fit the configuration and movement characteristics of human arms. In this scenario, people also have higher requirements for the flexibility of humanoid robotic arms.

[0003] The flexible features of the currently common humanoid robotic arms are mostly achieved by the control algorithms of the motors carried by the robotic arms. Most humanoid robotic arms are still rigid in structure, which leads to certain risks in human-computer interaction scenarios.

[0004] Therefore, there is an urgent need for a flexible and variable-rigidity humanoid robotic arm with a variable fulcrum. Summary of the invention

[0005] In view of the above technical problems, the present invention provides a flexible and variable-rigidity humanoid robotic arm with variable fulcrums.

[0006] The technical solution provided by the present invention is as follows:

[0007] A flexible and variable-rigidity humanoid mechanical arm with a variable fulcrum, comprising:

[0008] A shoulder joint serial module, comprising a first drive unit, a second drive unit and a third drive unit connected in sequence, for realizing rotation with three vertical degrees of freedom;

[0009] An elbow joint drive module, including a fourth drive unit and a connecting rod system;

[0010] The elbow joint elastic input module comprises a guide rail assembly, an elastic assembly and a fixed assembly; the elastic assembly comprises an optical axis with a linear bearing and a spring assembly; the guide rail assembly comprises a guide rail, a first slider assembly and a guide rail rotating shaft; one end of the guide rail is connected to the linear bearing through the first slider assembly, and the other end is connected through the guide rail rotating shaft; the fixed assembly is used to clamp the spring assembly, connect the guide rail assembly through the guide rail rotating shaft and receive external input power;

[0011] The elbow joint variable stiffness module comprises a bracket, a lead screw assembly, a second slider assembly and a variable stiffness driver; the lead screw assembly is fixed in the bracket, and its lead screw nut is connected to the guide rail through the second slider assembly; the variable stiffness driver is used to drive the lead screw; the bracket is movably connected to the fixed assembly; the guide rail rotating shaft is driven by the fixed assembly to make the guide rail rotate around the lead screw nut and drive the first slider assembly to move, thereby making the linear bearing move elastically along the optical axis under the action of the spring;

[0012] The terminal interaction module is used to install interactive components.

[0013] In one possible implementation, the first, second, third and fourth drive units all include SEA drive motors.

[0014] In a possible implementation, the first drive unit includes a first output connector for connecting to the second drive unit; the first output connector is arc-shaped, and is used to achieve vertical rotational freedom of the first drive unit and the second drive unit.

[0015] In a possible implementation, the second drive unit includes a second output connector for connecting to the third drive unit; the second output connector is a straight plate structure to achieve vertical rotational freedom of the second drive unit and the third drive unit.

[0016] In a possible implementation, the connecting rod system includes a connecting rod input plate and a fisheye bearing connecting rod; the fisheye bearing connecting rod is connected to a fixing component.

[0017] In a possible implementation, the spring assembly includes a fixed baffle, an optical axis fixing flange and a spring which are connected in sequence; the fixed baffle is connected to the fixing assembly; and elastic assemblies are provided at both ends of the optical axis.

[0018] In one possible implementation, the fixing assembly includes a first fixing ring, a first fixing plate, a second fixing ring and a second fixing plate; the first fixing ring is arranged on the first fixing plate, and the second fixing ring is arranged on the second fixing plate, and the two are symmetrically arranged for clamping the guide rail assembly and the elastic assembly.

[0019] In one possible implementation, the first slider assembly includes a rotating bearing, a slider rotating ring and a first slider connected in sequence; the rotating bearing is connected to one side of the linear bearing; the first slider is placed on a guide rail and can slide along the guide rail; the slider assembly is symmetrically arranged on both sides of the linear bearing.

[0020] In one possible implementation, the screw assembly includes a screw and a screw nut; the screw nut is arranged in the guide rail, between the rotating shaft and the first slider assembly.

[0021] In a possible implementation, the second slider assembly includes a deep groove ball bearing, a flange bearing, and a second slider that are connected in sequence; the deep groove ball bearing is connected to the lead screw nut.

[0022] The beneficial effects of the present invention are as follows:

[0023] 1. The shoulder joint series module of the present invention adopts a three-degree-of-freedom, integrated drive unit with a simple structure and small size;

[0024] 2. The variable stiffness flexible drive joint of the present invention comprises an elastic input module and a variable stiffness module, wherein the elastic input module comprises a guide rail assembly, an elastic assembly and a fixing assembly, and the variable stiffness module comprises a bracket, a lead screw assembly, a second slider assembly and a variable stiffness driver. The flexible variable stiffness adjustment is realized by utilizing the integrated design and synergistic effect of the above two modules;

[0025] 3. The robotic arm of the present invention provides a new idea for humanoid design and has great application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 , Figure 2 A schematic diagram of the structure of a humanoid robotic arm provided in an embodiment of the present invention;

[0027] Figure 3 It is a schematic structural diagram of a shoulder joint series flexible module provided in an embodiment of the present invention;

[0028] Figure 4 It is a structural schematic diagram of an elbow joint driving module provided in an embodiment of the present invention;

[0029] Figure 5 It is a schematic diagram of the structure of the elbow joint elastic input module, the elbow joint variable stiffness module and the terminal interaction module provided in the embodiment of the present invention;

[0030] Figure 6 It is a schematic structural diagram of an elbow joint elastic input module provided in an embodiment of the present invention;

[0031] Figure 7 It is an exploded schematic diagram of the structure of the elbow joint elastic input module provided in an embodiment of the present invention;

[0032] Figure 8 It is a schematic diagram of the structure of the elbow joint variable stiffness module provided in an embodiment of the present invention;

[0033] Fig. 9 An exploded schematic diagram of an elbow joint variable stiffness module structure provided in an embodiment of the present invention;

[0034] Fig.10A top view of the elbow joint variable stiffness module structure provided in an embodiment of the present invention;

[0035] Fig.11 It is a structural schematic diagram of the SEA module provided in an embodiment of the present invention;

[0036] Fig.12 A schematic diagram of the principle of a driving joint provided in an embodiment of the present invention;

[0037] In the attached figure: Ⅰ, shoulder joint series flexible module; Ⅱ, elbow joint drive module; Ⅲ, elbow joint elastic input module; Ⅳ, elbow joint variable stiffness module; Ⅴ, end interaction module; 1, arm connection carbon plate; 2, first SEA drive motor; 3, shoulder joint skeleton; 4, first output structure; 5, first output connector; 6, second output structure; 7, second SEA drive motor; 8, third SEA drive motor; 9, second output connector; 10, third output structure; 11, fisheye bearing connecting rod; 12, connecting rod input Plate; 13, first motor fixing frame; 14, shoulder elbow transition connector; 15, fourth SEA drive motor; 16, second motor fixing frame; 17, first fixing ring; 18, first fixing plate; 19, thrust roller bearing I; 20, first guide rail; 21, guide rail rotating shaft; 22, first flange bearing; 23, second guide rail; 24, second flange bearing; 25, second fixing plate; 26, thrust roller bearing II; 27, linear bearing; 28, optical axis; 29, rotating bearing; 30, first spring flange; 31 , spring; 32, second spring rib; 33, optical axis fixing flange; 34, fixed baffle; 35, slider rotating ring; 36, first slider; 41, ball bearing; 42, rib bearing I; 43, first deep groove ball bearing; 44, rib bearing II; 45, second slider; 46, slider rotating shaft; 47, deep groove ball bearing; 48, lead screw nut; 49, lead screw; 50, second deep groove ball bearing; 51, first lead screw end fixing bracket; 52, deep groove ball bearing; 53, axial positioning ring; 54, 485 code Device; 55, slider guide; 56, screw input bracket; 57, second output plate; 58, variable stiffness main and auxiliary motors; 59, second screw end bracket; 60, first output plate; 101, SEA drive motor; 102, connecting transition piece; 103, under the spring frame; 104, on the spring frame; 105, under the drive motor frame; 106, array spring; 107, on the drive motor frame; 108, deep groove ball bearing I; 109, 485 encoder; 110, housing output end; 111, deep groove ball bearing II. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0040] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0041] See also Figure 1 , Figure 2 , which is a flexible and variable stiffness humanoid robot arm with variable fulcrum, comprising:

[0042] A flexible and variable-rigidity humanoid mechanical arm with a variable fulcrum, comprising:

[0043] The shoulder joint serial module I comprises a first drive unit, a second drive unit and a third drive unit connected in sequence, and is used to realize rotation with three vertical degrees of freedom;

[0044] Elbow joint drive module II, including a fourth drive unit and a connecting rod system;

[0045] Elbow joint elastic input module III, including a guide rail assembly, an elastic assembly and a fixed assembly; the elastic assembly includes an optical axis 28 with a linear bearing 27 and a spring assembly; the guide rail assembly includes a guide rail, a first slider assembly and a guide rail rotating shaft 21; one end of the guide rail is connected to the linear bearing 27 through the first slider assembly, and the other end is connected through the guide rail rotating shaft 21; the fixed assembly is used to clamp the spring assembly, connect the guide rail assembly through the guide rail rotating shaft 5 and receive external input power;

[0046] The elbow joint variable stiffness module III comprises a bracket, a lead screw assembly, a second slider assembly and a variable stiffness driver; the lead screw assembly is fixed in the bracket, and its lead screw nut is connected to the guide rail through the second slider assembly; the variable stiffness driver is used to drive the lead screw; the bracket is movably connected to the fixed assembly; the guide rail rotating shaft 21 is driven by the fixed assembly to make the guide rail rotate around the lead screw nut and drive the first slider assembly to move, thereby making the linear bearing 27 elastically move along the optical axis 28 under the action of the spring 31;

[0047] Terminal interaction module IV is used to install interactive components.

[0048] In one possible implementation, the first, second, third and fourth drive units all include SEA drive motors.

[0049] In a possible implementation, the first drive unit includes a first output connector 5 for connecting to the second drive unit; the first output connector 5 is arc-shaped, for achieving vertical rotational freedom of the first drive unit and the second drive unit.

[0050] In a possible implementation, the second drive unit includes a second output connector 9 for connecting to the third drive unit; the second output connector 9 is a straight plate structure to achieve vertical rotational freedom of the second drive unit and the third drive unit.

[0051] For example, see Figure 3 , the first SEA drive motor 2 is fixed to the arm connection carbon plate 1 through the shoulder joint skeleton 3. The first output structure 4 is the output end of the SEA drive motor 2, connected to the first output connector 5. The first output connector 5 is an arc-shaped structure, which is bent toward the second SEA drive motor 7 and connected thereto. Similarly, the second output structure 6 is connected to the third SEA drive motor 8 through the second output connector 9. The rotation directions of the three SEA drive motors are perpendicular to each other to achieve rotation with three degrees of freedom.

[0052] In a possible implementation, the connecting rod system includes a connecting rod input plate 12 and a fisheye bearing connecting rod 11; the fisheye bearing connecting rod 11 is connected to a fixed component.

[0053] For example, see Figure 4 The fourth drive unit includes a first motor fixing frame 13, a shoulder elbow transition connector 14, a fourth SEA drive motor 15 and a second motor fixing frame 16. The fourth SEA drive motor 15 is clamped and fixed by the first motor fixing frame 13 and the second motor fixing frame 16, and the shoulder elbow transition connector 14 is fixed to the fourth SEA drive motor 15 and connected to the output end of the third drive unit. The connecting rod input disc 12 is an annular structure with bolts, which is used to limit the fisheye bearing connecting rod 11.

[0054] Specifically, the first motor fixing bracket 13 is a flange plate for matching the motor.

[0055] Specifically, the second motor fixing frame 16 includes a motor wrapping portion and a connecting portion; the motor wrapping portion is an arc-shaped surface for wrapping and supporting the motor; the connecting portion is a flat plate with a circular groove, for supporting the motor wrapping portion and connecting the elbow joint elastic input module III.

[0056] In one possible implementation, Figure 5-6As shown, the spring assembly includes a fixed baffle 34, an optical axis fixing flange 33 and a spring 31 which are connected in sequence; the fixed baffle 34 is connected to the fixing assembly; and spring assemblies are provided at both ends of the optical axis 28.

[0057] Furthermore, a first spring rib 30 and a second spring rib 32 are provided at both ends of the spring 31 .

[0058] Furthermore, the spring 31 is in a compressed state during the entire movement process.

[0059] It can be understood that the two compression springs 31 stabilize the linear bearing 27 in the center position; the compression spring is always in a compressed state, and is provided with two spring retaining edges 30 and 32 to prevent it from deviating from the axial position; the central optical axis 28 not only plays a directional role for the linear bearing 27, but also guides the spring to ensure that the two compression springs will not cause the compression rod to become unstable when subjected to pressure.

[0060] In one possible implementation, the fixing assembly includes a first fixing ring 17, a first fixing plate 18, a second fixing ring 25 and a second fixing plate; the first fixing ring 17 is arranged on the first fixing plate 18, and the second fixing ring 25 is arranged on the second fixing plate, and the two are symmetrically arranged for clamping and fixing the guide rail assembly and the elastic assembly.

[0061] See also Figure 7 The first fixing ring 17 and the second fixing ring 25 are flanges. The first fixing plate 18 and the second fixing ring 25 are fan-shaped structures, with a round hole matching the fixing ring in the wide part, a connecting plate for connecting the fixing baffle 34 is arranged on the end surface perpendicular to the fan surface, and a hole is opened in the narrow part for installing the guide rail shaft 21.

[0062] In one possible implementation, the first slider assembly includes a rotating bearing 29, a slider rotating ring 35 and a slider 36 connected in sequence; the rotating bearing 29 is connected to one side of the linear bearing 27, and the slider 36 is placed on the guide rail and can slide along the guide rail; the slider assembly is symmetrically arranged on both sides of the linear bearing 27.

[0063] Specifically, the guide rail includes a track and a protective shell, and the track is placed in the protective shell.

[0064] Specifically, the guide rail shaft 21 forms a stable and movable connection with the first fixing ring 17 and the second fixing ring 25 through the thrust roller bearing I19, the first flange bearing 21, the second flange bearing 24 and the thrust roller bearing II 26.

[0065] In one possible implementation, the bracket is a square frame, one end of which is movably connected to the fixing assembly through axial fit.

[0066] For details, see Figure 8 and Fig. 9 The bracket includes a first output plate 60, a second output plate 57, a first screw end fixing frame 51, a screw input fixing frame 56 and a second screw end fixing frame 59. The first output plate 60 and the second output plate 57 are supported by the first screw end fixing frame 51, the screw input fixing frame 56 and the second screw end fixing frame 59 to form a square frame structure. The first screw end fixing frame 51 and the screw input fixing frame 56 are used to fix the screw 49, and the screw input fixing frame 56 and the second screw end fixing frame 59 are used to fix the variable stiffness driver.

[0067] Specifically, the one end is connected to the fixed assembly through axial cooperation in the following manner: a second deep groove ball bearing 52 , an axial positioning ring 53 and a 485 encoder 54 are provided to realize a movable connection between the bracket and the fixed assembly.

[0068] It should be noted that Figure 5-9 In the figure, the guide rail assembly is involved in both figures in order to better show the structure and connection relationship. In fact, the guide rail assembly belongs to the elastic input module. Similarly, the ball bearing 41, the flange bearing I 42 and the flange bearing II 44 are actually the same set of components as the thrust roller bearing II 26, the second flange bearing 24 and the first flange bearing 22.

[0069] In a possible implementation, the screw assembly includes a screw 49 and a screw nut 48; the screw nut 48 is disposed in the guide rail and is located between the guide rail rotating shaft 21 and the first slider assembly.

[0070] In a possible implementation, the second slider assembly includes a deep groove ball bearing 47, a slider rotating shaft 46 and a second slider 45 connected in sequence; the deep groove ball bearing 47 is connected to a lead screw nut 48. In a possible implementation, the variable stiffness flexible drive joint further includes an interaction module.

[0071] Furthermore, the variable stiffness drive includes variable stiffness main and auxiliary motors 38 .

[0072] Furthermore, the interaction module includes a dexterous hand or a gripper.

[0073] For details, see Fig.10 In the variable stiffness main and auxiliary motors, the main motor is used to drive the screw assembly, and the auxiliary motor is used to drive the interactive module.

[0074] Specifically, the variable stiffness main and auxiliary motors are two RoboMaster M3508 motors arranged in parallel.

[0075] In one possible implementation, see Fig.11The SEA driver module includes a SEmotor SETZ90 series motor produced by Shenzhen Xiaoxiang Electric Technology Co., Ltd., which is specifically composed of six linear tension spring arrays 106 forming a hexagonal layout, and the two ends of the tension spring are respectively fixed between the upper spring frame 104 and the lower spring frame 103 by bolts, and the lower spring frame is fixedly connected to the output end of the drive motor 101 through a connecting transition piece; the lower spring frame is then concentrically matched with the lower spring frame through a deep groove ball bearing Ⅰ108; the adjacent two petals of the upper and lower spring frames form an angle of 60 degrees in a balanced state; the six tension springs are installed between the two spring frames in a pre-tensioned state, and the upper spring frames are limited by a structural limit. A torsion angle of up to ±15 degrees offset from the equilibrium position is formed between the lower two spring frames, and the selected tension spring is always guaranteed to be in a stretched state within this torsion range; the large end of the encoder is fixed on the upper spring frame, and the output shaft of the 485 encoder 109 is fixed on the lower spring frame through a D-shaped shaft hole, so the encoder is used to record the torsion angle between the upper and lower spring frames; the output shaft is fixedly connected to the upper spring frame, and forms a concentric fit with the drive motor frame 107 through a deep groove ball bearing II 111; finally, the output end is fixed to the external connector through bolts to form a complete transmission chain of torque.

[0076] The following describes the movement principle of the robot arm based on its structure described in this embodiment.

[0077] The shoulder joint series module I realizes the rotation of three vertical degrees of freedom through the rotation of the SEA motor. In the elbow joint drive module II, the SEA motor drives the fisheye bearing connecting rod 11 to rotate, and the output end of the fisheye bearing connecting rod 11 drives the first fixed ring 17 to rotate, and then drives the guide rail to rotate through the guide rail rotating shaft 21. In the elbow joint elastic input module III, two compression springs 31 stabilize the linear bearing 27 in the center position. Fig.12 , when no force is applied initially, the linear bearing 11 and the first slider 20 at point C are at equilibrium at point O, and the lead screw nut 48 and the second slider 45 at point B also fall on the center line AO. In the figure, the guide rail and the lead screw are initially in an overlapping state. When an external force torque τ is applied to this structure, the entire system will be twisted as shown in the figure, and the overall twist angle is Under the action of torque, the guide rail, driven by the guide rail shaft 21 (point A), will rotate around point B (screw nut 48) at an angle of α. The other end, point C (linear bearing 11), will provide axial thrust to the spring system, compress the spring, and store energy for the elastic system. In the elbow joint variable stiffness module IV, the auxiliary motor of the variable stiffness module drives the ball screw to change the preload of the compression spring to achieve variable stiffness adjustment.

[0078] Fig.12 In, l OCrepresents the relative compression of the elastic system, ρ represents the effective length of the variable stiffness of the ball screw input, and λ represents the end length of the guide rail lever, which will produce a small change when the system is twisted and is a variable.

[0079] When the variable stiffness flexible actuated joint (VSA) deflects, its initial potential energy and the changed potential energy are expressed as:

[0080]

[0081] The double compression spring system can be regarded as two parallel springs, and the resulting stiffness is 2k. VSA0 Assume that the initial elastic potential energy of the elastic system is 0 in the initial state, E VSAs It is expressed as the torsion angle of VSA is In this case, the elastic potential energy stored in VSA.

[0082] The first-order derivative of the total elastic potential energy stored in the VSA with respect to the torsion angle is the output torque of the system, and the second-order derivative is the torsional stiffness of the VSA. The torque and stiffness expressions of the VSA are as follows:

[0083]

[0084] Among them, τ VSAex represents the torque of VSA, k VSAex Represents the stiffness of the VSA.

[0085] The stiffness analytical expression of VSA variable stiffness flexible actuator is:

[0086]

[0087] Among them, l OC Indicates the spring compression stroke, l AO Indicates the distance of the linear bearing at the initial position of the guide shaft.

[0088] The above description is only a preferred specific implementation manner of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the scope of protection of the invention.

Claims

1. A flexible and variable stiffness humanoid robot arm with variable fulcrum, characterized in that: Includes the following connected in sequence: A shoulder joint serial module, comprising a first drive unit, a second drive unit and a third drive unit connected in sequence, for realizing rotation with three vertical degrees of freedom; An elbow joint drive module, including a fourth drive unit and a connecting rod system; The elbow joint elastic input module comprises a guide rail assembly, an elastic assembly and a fixed assembly; the elastic assembly comprises an optical axis with a linear bearing and a spring assembly; the guide rail assembly comprises a guide rail, a first slider assembly and a guide rail rotating shaft; one end of the guide rail is connected to the linear bearing through the first slider assembly, and the other end is connected through the guide rail rotating shaft; the fixed assembly is used to clamp the spring assembly, connect the guide rail assembly through the guide rail rotating shaft and receive external input power; The elbow joint variable stiffness module comprises a bracket, a lead screw assembly, a second slider assembly and a variable stiffness driver; the lead screw assembly is fixed in the bracket, and its lead screw nut is connected to the guide rail through the second slider assembly; the variable stiffness driver is used to drive the lead screw; the bracket is movably connected to the fixed assembly; the guide rail rotating shaft is driven by the fixed assembly to make the guide rail rotate around the lead screw nut and drive the first slider assembly to move, thereby making the linear bearing move elastically along the optical axis under the action of the spring; The terminal interaction module is used to install interactive components.

2. The flexible and variable stiffness humanoid robot arm with variable pivot points according to claim 1, characterized in that: The first, second, third and fourth drive units all include SEA drive motors.

3. The flexible and variable stiffness humanoid robot arm with variable pivot points according to claim 1, characterized in that: The first driving unit comprises a first output connecting member for connecting with the second driving unit; the first output connecting member is arc-shaped, for realizing vertical rotational freedom of the first driving unit and the second driving unit.

4. The flexible and variable stiffness humanoid robot arm with variable pivot points according to claim 1, characterized in that: The second driving unit includes a second output connecting member for connecting to the third driving unit; the second output connecting member is a straight plate structure to achieve vertical rotational freedom of the second driving unit and the third driving unit.

5. The flexible and variable stiffness humanoid robot arm with variable pivot points according to claim 1, characterized in that: The connecting rod system includes a connecting rod input plate and a fisheye bearing connecting rod; the fisheye bearing connecting rod is connected to a fixed component.

6. The flexible and variable stiffness humanoid robot arm with variable pivot points according to claim 1, characterized in that: The spring assembly comprises a fixed baffle, an optical axis fixing flange and a spring which are connected in sequence; the fixed baffle is connected to the fixing assembly; and elastic assemblies are arranged at both ends of the optical axis.

7. The flexible and variable stiffness humanoid robot arm with variable pivot points according to claim 1, characterized in that: The fixing assembly includes a first fixing ring, a first fixing plate, a second fixing ring and a second fixing plate; the first fixing ring is arranged on the first fixing plate, and the second fixing ring is arranged on the second fixing plate, and the two are symmetrically arranged for clamping the guide rail assembly and the elastic assembly.

8. The flexible and variable stiffness humanoid robot arm with variable pivot points according to claim 1, characterized in that: The first slider assembly includes a rotating bearing, a slider rotating ring and a first slider connected in sequence; the rotating bearing is connected to one side of the linear bearing; the first slider is placed on the guide rail and can slide along the guide rail; the slider assembly is symmetrically arranged on both sides of the linear bearing.

9. The flexible and variable stiffness humanoid robot arm with variable pivot points according to claim 1, characterized in that: The lead screw assembly comprises a lead screw and a lead screw nut; the lead screw nut is arranged in the guide rail, between the rotating shaft and the first slider assembly.

10. The flexible and variable stiffness humanoid robot arm with variable pivot points according to claim 1, characterized in that: The second slider assembly includes a deep groove ball bearing, a flange bearing and a second slider which are connected in sequence; the deep groove ball bearing is connected to the lead screw nut.

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