A rope-driven human upper limb simulation based on self-similar tensegrity joints

Abstract

The present invention provides a rope-driven human upper limb simulation based on a self-similar tensegrity joint, and belongs to the field of robotics technology. The human upper limb simulation includes a tensegrity joint, an upper arm, a forearm, a manipulator, and a driving rope, wherein the tensegrity joint is composed of a tension spring and connecting parts such as a double-headed ball joint or a connecting rod, and a deformation effect such as bending and twisting is achieved by designing a rope threading method. The tensegrity joint includes a self-similar shoulder joint, an elbow joint, and a wrist joint, wherein the lower end of the shoulder joint is connected to the upper arm, the two ends of the elbow joint are connected to the upper arm and the forearm respectively, the upper end of the wrist joint is connected to the forearm and the lower end is connected to the manipulator, and by regulating the driving rope, both the independent movement of a single joint and the overall movement of the upper limb can be achieved. Compared with a rigid mechanical upper limb, the present invention uses ropes to simulate the tendons of a human arm, and each designed joint has a high degree of self-similarity, high degree of freedom, light weight, simple structure, and easy installation.

Description

Technical Field

[0001] The invention relates to the technical field of robots, in particular to a rope-driven imitation of human upper limbs based on a self-similar tensioned integral joint. Background Art

[0002] Common humanoid upper limb designs usually use complex transmission structures such as gears and connecting rods. These structures are heavy and large in size, resulting in complex upper limb joints. They are also easily affected by environmental conditions and service life, and are often difficult to apply to application scenarios that require lightweight and miniaturized humanoid upper limbs. How to design a humanoid upper limb that has multiple degrees of freedom, is lightweight and miniaturized is one of the difficulties in the field of robotics. The tensegrity structure is a structural system composed of a series of discontinuous compression units and continuous tension units interacting with each other. It has the advantages of light weight and large deformation. By introducing the tensegrity structure, the number of parts in each joint of the upper limb can be reduced, the joint mass can be reduced, and the friction loss can be reduced. To this end, based on the tensegrity structure, the present invention discloses a novel rope-driven humanoid upper limb based on a self-similar tensegrity joint. Summary of the invention

[0003] The present invention aims to solve the shortcomings of traditional human upper limb joints, such as large size, heavy weight and limited freedom of movement, and provides a rope-driven human upper limb simulation based on self-similar tension integral joints. The joints of the upper limb are structurally composed of only tension units and compression units, with a simple structure and small size. In addition, the joints designed by the present invention are self-similar multi-level structures. Since the shoulder, elbow and wrist joints are highly similar, they can share similar manufacturing processes and maintenance methods. This design helps to simplify the manufacturing and maintenance processes and improve efficiency. In terms of driving, a number of flexible ropes are used to simulate human tendons, and by designing the rope threading method of the joints, various deformations such as bending and twisting of the upper limb as a whole can be achieved, with good compliant control effects.

[0004] In order to solve the above-mentioned invention object, the technical solution provided by the present invention is as follows:

[0005] A rope-driven human upper limb simulation based on a self-similar tensegrity joint comprises a tensegrity joint, an upper arm, a forearm, a manipulator, and a driving rope.

[0006] The tensegrity joints include shoulder joints, elbow joints and wrist joints.

[0007] The lower end of the shoulder joint is connected to the upper arm,

[0008] The upper end of the elbow joint is connected to the upper arm, and the lower end of the elbow joint is connected to the forearm.

[0009] The upper end of the wrist joint is connected to the forearm, and the lower end of the wrist joint is connected to the manipulator;

[0010] The driving rope is connected to the lower end of the tensegrity joint, and the motor drives the rope to drive the entire upper limb to deform.

[0011] The upper arm and forearm are cylindrical or columnar structures.

[0012] The tensioned integral joint is composed of a tension unit and a compression unit, the tension unit is a tension spring, and the compression unit is divided into a double-headed ball joint and a connecting rod according to the degrees of freedom of the shoulder, elbow and wrist joints of the human body. The compression units of the wrist joint and the shoulder joint are double-headed ball joints, so that the shoulder and wrist joints can bend in all directions, and the compression unit of the elbow joint is a connecting rod.

[0013] The wrist joint and shoulder joint have the same structure.

[0014] The wrist joint comprises a wrist joint lower end, a ball joint base, a double-headed ball joint, a tension unit and a wrist joint upper end.

[0015] The ball joint base is installed at the center of the lower end and the upper end of the wrist joint, one end of the double-headed ball joint is placed in the ball joint base at the lower end of the wrist joint, and the other end of the double-headed ball joint is placed in the ball joint base at the upper end of the wrist joint;

[0016] Three ears are arranged on the circumference of the lower end of the wrist joint, the angle between adjacent ears is 120°, hooks are arranged on the ears away from the center of the circumference, and through holes are opened on the ears for the driving rope to pass through;

[0017] The upper end of the wrist joint is symmetrical with the lower end of the wrist joint in structure, and the upper end of the wrist joint is rotated 60 degrees along the center of the double-headed ball joint end.

[0018] The elbow joint comprises a lower end of the elbow joint, a hinged baffle, a connecting rod and an upper end of the elbow joint,

[0019] The hinged baffle is fixedly installed at the center of the lower end of the elbow joint, the hinged baffle is connected to the lower end of the connecting rod through a pin shaft, and the upper end of the connecting rod is fixedly connected to the center of the upper end of the elbow joint;

[0020] Three ears are arranged on the circumference of the lower end of the elbow joint, and the angle between adjacent ears is 120°. A hook is arranged on the ear away from the center of the circumference, and a through hole is opened on the ear for the driving rope to pass through. One of the ears extends a protrusion at a symmetrical position of the circumference, and a through hole is opened on the protrusion for the driving rope to pass through;

[0021] The upper end of the elbow joint is symmetrical with the lower end of the elbow joint in structure, and the upper end of the elbow joint is rotated 180 degrees along the center where the end of the connecting rod is located.

[0022] The tension unit is six tension springs, and the hooks at both ends of the tension springs are respectively hooked with the hooks at the upper and lower ends of the tensioned integral joint. Every two adjacent tension springs are regarded as a group, and the two springs in each group are arranged at an angle of 60° in the initial state.

[0023] The height between the upper and lower ends of the tensioned integral joint is greater than the original length of the tension spring to avoid compression problems in the tension unit; the center of mass of the ball joint must be located outside the hook and ring connection points of the tension springs at both ends of the shoulder / wrist joint to ensure the stability of the structure.

[0024] The human elbow joint cannot be twisted and can only bend in one plane, and the bending angle is greatly limited, and it can only bend to one side. Therefore, structures that limit the reverse bending of the connecting rod are provided in the upper and lower ends of the elbow joint.

[0025] There are fourteen driving ropes in total, of which two are for the elbow joint, and six are for the wrist joint and the shoulder joint respectively;

[0026] One end of the driving rope passes through the through hole of the ear at the lower end of the tensegrity joint and is fixed, and the other end is connected to the motor;

[0027] When the upper limb is initially in an extended state, the distribution of the driving ropes in the shoulder joint and wrist joint is the same as that of the tension spring. The six ropes are grouped in two, and the ropes in the same group form an angle of 60°; the two ropes of the elbow joint are symmetrically distributed on both sides.

[0028] The manipulator, wrist joint, forearm, elbow joint, upper arm and shoulder joint are connected in series in sequence, and a unique rope threading method is designed in each joint and driven by different groups of ropes. Each group of ropes is connected to the corresponding joint, and the structure formed is the tensegrity human upper limb designed by the present invention. According to the actual degree of freedom of the human upper limb joints, the wrist joint and shoulder joint designed by the present invention can both achieve twisting and bending, and the elbow joint can only achieve bending movement.

[0029] In the present invention, the upper and lower ends of the tensioned integral joint and the compression rods are made of lightweight, high-buffering and energy-absorbing materials, such as epoxy resin and aluminum alloy; the tension unit can choose springs and shape memory alloys; the ball joint can choose any structure with omnidirectional rotation function; the above components can be selected and replaced according to needs.

[0030] Compared with the prior art, the above technical solution has at least the following beneficial effects:

[0031] Compared with the traditional rigid human-like upper limb design, the above scheme introduces a tensegrity structure, so that the joints of the upper limbs have a simple structure, light weight and small size.

[0032] The present invention uses a rope drive to simulate the expansion and contraction process of human tendons, has good bending and torsion coupling, and can achieve good flexible control of each joint. According to different rope drive schemes, each joint will produce corresponding deformation. For example, for the shoulder / wrist joint, the symmetrical drive scheme relative to the middle axis of the joint will produce bending deformation, and the asymmetric drive scheme will produce bending and torsion coupling deformation.

[0033] The highly self-similar joints designed in the present invention can not only form a human upper limb, but also form structures such as multi-joint bionic animals or mechanical claws by connecting the tensegrity joints in series and parallel. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 This is a schematic diagram of the overall structure of a rope-driven human upper limb based on a self-similar tensegrity integral joint according to the present invention;

[0036] Figure 2 It is a schematic diagram of the shoulder joint structure of the human upper limbs driven by the rope based on the self-similar tensegrity joint of the present invention;

[0037] Figure 3 It is a schematic diagram of the elbow joint structure of the human upper limbs driven by the rope based on the self-similar tensegrity integral joint of the present invention;

[0038] Figure 4 It is a schematic diagram of the bending state configuration of the self-similar tensegrity integral joint of the human upper limb under unilateral rope contraction in an embodiment of the present invention.

[0039] Among them: 1-manipulator; 2-wrist joint; 3-forearm; 4-elbow joint; 5-upper arm; 6-shoulder joint;

[0040] 401- lower end of elbow joint; 402- hinged baffle; 403- connecting rod; 404- upper end of elbow joint;

[0041] 601-lower end of shoulder joint; 602-ball joint base; 603-double-headed ball joint; 604-tension unit; 605-upper end of shoulder joint; 606-driving rope. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment 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.

[0043] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0044] It should be noted that the terms "up", "down", "left", "right", "front", "back", etc. used in the present invention are only used to indicate relative position relationships. When the absolute position of the described object changes, the relative position relationship may also change accordingly.

[0045] The invention provides a rope-driven imitation human upper limb based on a self-similar tensegrity joint.

[0046] like Figure 1 The rope-driven human upper limb includes a tensegrity joint, an upper arm 5, a forearm 3, a manipulator 1 and a driving rope 606.

[0047] The tensegrity joint comprises a wrist joint 2, an elbow joint 4 and a shoulder joint 6, each of which has the same structural dimensions and mechanical properties;

[0048] The upper end of the wrist joint 2 is connected to the forearm 3, and the lower end of the wrist joint 2 is provided with a through hole, which is connected to the manipulator 1 through a connector. The connector is designed according to the specific structure and size of the manipulator 1, and the manipulator 1 can select an existing finished product according to the needs;

[0049] The upper end of the elbow joint 4 is connected to the upper arm 5, and the lower end of the elbow joint 4 is connected to the forearm 3.

[0050] The lower end of the shoulder joint 6 is connected to the upper arm 5;

[0051] The driving rope 606 is connected to the lower end of the tensegrity joint, and the motor drives the rope to drive the entire upper limb to deform.

[0052] The tensegrity joint is composed of a tension unit and a compression unit, wherein the tension unit is a tension spring, the compression units of the wrist joint and the shoulder joint are double-headed ball joints, and the compression unit of the elbow joint is a connecting rod.

[0053] like Figure 2 In the present invention, the wrist joint and the shoulder joint have the same structure, and the shoulder joint is taken as an example:

[0054] The shoulder joint 6 includes a shoulder joint lower end 601, a ball joint base 602, a double-headed ball joint 603, a tension unit 604 and a shoulder joint upper end 605.

[0055] The ball joint base 602 is installed at the center of the shoulder joint lower end 601 and the shoulder joint upper end 605, one end of the double-headed ball joint 603 is placed in the ball joint base of the shoulder joint lower end 601, and the other end of the double-headed ball joint 603 is placed in the ball joint base of the shoulder joint upper end 605;

[0056] Three ears are arranged on the circumference of the lower end 601 of the shoulder joint, and the angle between adjacent ears is 120°. A hook is arranged on the ear away from the center of the circumference, and a through hole is opened on the ear for the driving rope 606 to pass through;

[0057] The shoulder joint upper end 605 is symmetrical in structure with the shoulder joint lower end 601, and the shoulder joint upper end is rotated 60 degrees along the center of the double-headed ball joint end.

[0058] like Figure 3 The elbow joint 4 includes an elbow joint lower end 401, a hinged baffle 402, a connecting rod 403 and an elbow joint upper end 404.

[0059] The hinged baffle 402 is fixedly installed at the center of the lower end 401 of the elbow joint, the hinged baffle 402 is connected to the lower end of the connecting rod 403 through a pin shaft, and the upper end of the connecting rod 403 is fixedly connected to the center of the upper end 404 of the elbow joint;

[0060] Three ears are arranged on the circumference of the lower end of the elbow joint, and the angle between adjacent ears is 120°. A hook is arranged on the ear away from the center of the circumference, and a through hole is opened on the ear for the driving rope to pass through. One of the ears extends a protrusion at a symmetrical position of the circumference, and a through hole is opened on the protrusion for the driving rope to pass through;

[0061] The upper end of the elbow joint is symmetrical with the lower end of the elbow joint in structure, and the upper end of the elbow joint is rotated 180 degrees along the center where the end of the connecting rod is located.

[0062] The tension unit is six tension springs, and the hooks at both ends of the tension springs are respectively hooked with the hooks at the upper and lower ends of the tensioned integral joint. Every two adjacent tension springs are regarded as a group, and the two springs in each group are arranged at an angle of 60° in the initial state.

[0063] The height between the upper and lower ends of the tensegrity joint is greater than the original length of the tension spring.

[0064] The upper and lower ends of the elbow joint are both provided with structures for limiting the reverse bending of the connecting rod.

[0065] There are fourteen driving ropes in total, of which two are for the elbow joint, and six are for the wrist joint and the shoulder joint respectively;

[0066] One end of the driving rope passes through the through hole of the ear at the lower end of the tensegrity joint and is fixed, and the other end is connected to the motor;

[0067] When the upper limb is initially in an extended state, the distribution of the driving ropes in the shoulder joint and wrist joint is the same as that of the tension spring. The six ropes are grouped in two, and the ropes in the same group form an angle of 60°; the two ropes of the elbow joint are symmetrically distributed on both sides.

[0068] In the present invention, the drive ropes in the shoulder / wrist joint and the elbow joint are arranged differently, so that in practical applications, the motor sets a contraction amount of the drive rope, and the drive rope drives the lower end of the joint to deform accordingly.

[0069] according to Figure 2 As shown in the figure, in the initial state of the shoulder / wrist joint, the structure consists of the upper and lower ends of the joint, six tension springs, six driving ropes, a ball joint base and a double-headed ball joint. The six ropes can be evenly divided into three groups according to their distribution, with two ropes in each group. When two ropes in the same group are driven at the same time and the rope changes are the same, the joint bends toward one side of the tensioned rope; when two ropes in different groups but symmetrically located relative to the middle axis are driven at the same time and the rope changes are the same, the joint bends toward the direction of the tensioned rope; when ropes in the same order (such as ropes on the right side of each group) in the three groups are driven at the same time and the rope changes are the same, the lower end of the joint undergoes corresponding twisting. The above are some of the driving schemes for the shoulder / wrist joint to achieve bending or twisting. In addition, specific driving schemes can also be designed to achieve bending and torsion coupling motion of the shoulder / wrist joint.

[0070] according to Figure 3 In the initial state of the elbow joint, the structure consists of the upper and lower ends of the joint, six tension springs, two driving ropes, and a connecting rod. The joint can only bend in a fixed plane, and the bending angle is limited by the baffles at the hinges at both ends of the joint. The two ropes are symmetrically distributed and located in the bending plane of the joint. Pulling the rope on the right side of the joint in the figure will cause the joint to bend to the right.

[0071] like Figure 4 As shown, the driving scheme of this embodiment is that only one side of the driving rope in the joint is pulled, and the figure shows that the rope on the left side of each joint is pulled. The specific working mechanism and deformation effect of the humanoid upper limb are as follows: the motor receives the pulse signal of the host computer, and the driving rope connected to the motor produces a corresponding contraction amount. At this time, the remaining motors receive the pulse signal to make the corresponding remaining driving ropes extend. Since each rope is connected to the lower end of the joint, and the two ends of the upper and forearms are respectively connected to the lower ends of each joint, the lower end of the joint drives the upper and forearms to rotate around the ball joint. At this time, the humanoid upper limb changes from the initial state to the bending state.

[0072] There are a few points to note:

[0073] (1) The drawings of the embodiments of the present invention only relate to the structures related to the embodiments of the present invention, and other structures may refer to the general design.

[0074] (2) In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0075] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A rope-driven human upper limb simulation based on a self-similar tensegrity joint, characterized in that: It includes tensegrity joint, upper arm, forearm, manipulator, drive rope, The tensegrity joints include shoulder joints, elbow joints and wrist joints. The lower end of the shoulder joint is connected to the upper arm, The upper end of the elbow joint is connected to the upper arm, and the lower end of the elbow joint is connected to the forearm. The upper end of the wrist joint is connected to the forearm, and the lower end of the wrist joint is connected to the manipulator; The driving rope is connected to the lower end of the tensegrity joint, and the motor drives the rope to cause the entire upper limb to deform; The tensegrity joint is composed of a tension unit and a compression unit, wherein the tension unit is a tension spring, the compression units of the wrist joint and the shoulder joint are double-headed ball joints, and the compression unit of the elbow joint is a connecting rod; The wrist joint and shoulder joint have the same structure. The wrist joint comprises a wrist joint lower end, a ball joint base, a double-headed ball joint, a tension unit and a wrist joint upper end. The ball joint base is installed at the center of the lower end and the upper end of the wrist joint, one end of the double-headed ball joint is placed in the ball joint base at the lower end of the wrist joint, and the other end of the double-headed ball joint is placed in the ball joint base at the upper end of the wrist joint; Three ears are arranged on the circumference of the lower end of the wrist joint, the angle between adjacent ears is 120°, hooks are arranged on the ears away from the center of the circumference, and through holes are opened on the ears for the driving rope to pass through; The upper end of the wrist joint is symmetrical with the lower end of the wrist joint in structure, and the upper end of the wrist joint is rotated 60 degrees along the center of the double-headed ball joint end; The tension unit is six tension springs, and the hooks at both ends of the tension springs are respectively hooked with the hooks at the upper and lower ends of the tensioned integral joint. Every two adjacent tension springs are regarded as a group, and the two springs in each group are arranged at an angle of 60° in the initial state.

2. The rope-driven simulation of human upper limbs based on self-similar tensegrity joints according to claim 1 is characterized in that: The elbow joint comprises a lower end of the elbow joint, a hinged baffle, a connecting rod and an upper end of the elbow joint, The hinged baffle is fixedly installed at the center of the lower end of the elbow joint, the hinged baffle is connected to the lower end of the connecting rod through a pin shaft, and the upper end of the connecting rod is fixedly connected to the center of the upper end of the elbow joint; Three ears are arranged on the circumference of the lower end of the elbow joint, and the angle between adjacent ears is 120°. A hook is arranged on the ear away from the center of the circumference, and a through hole is opened on the ear for the driving rope to pass through. One of the ears extends a protrusion at a symmetrical position of the circumference, and a through hole is opened on the protrusion for the driving rope to pass through; The upper end of the elbow joint is symmetrical with the lower end of the elbow joint in structure, and the upper end of the elbow joint is rotated 180 degrees along the center where the end of the connecting rod is located.

3. The rope-driven simulation of human upper limbs based on self-similar tensegrity joints according to claim 1 is characterized in that: The height between the upper and lower ends of the tensegrity joint is greater than the original length of the tension spring.

4. The rope-driven simulation of human upper limbs based on self-similar tensegrity joints according to claim 2 is characterized in that: The upper and lower ends of the elbow joint are both provided with structures for limiting the reverse bending of the connecting rod.

5. The rope-driven simulation of human upper limbs based on self-similar tensegrity joints according to claim 1 is characterized in that: There are fourteen driving ropes in total, of which two are for the elbow joint, and six are for the wrist joint and the shoulder joint respectively; One end of the driving rope passes through the through hole of the ear at the lower end of the tensegrity joint and is fixed, and the other end is connected to the motor; When the upper limb is initially in an extended state, the distribution of the driving ropes in the shoulder joint and wrist joint is the same as that of the tension spring. The six ropes are grouped in two, and the ropes in the same group form an angle of 60°; the two ropes of the elbow joint are symmetrically distributed on both sides.

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