A movement mechanism of a rope-driven dexterous hand thumb, a dexterous hand and a robot

Abstract

The application provides a motion mechanism of a rope-driven dexterous hand thumb, a dexterous hand and a robot. The motion mechanism comprises a base, a rotating seat, a thumb joint and at least one cross-joint tendon rope. The rotating seat is rotationally connected with the base and rotates relative to the base around a first axis under the driving of the driving tendon rope. The rotating seat is provided with a reversing piece. The cross-joint tendon rope extends to the thumb joint through a first passing piece and the reversing piece in sequence to drive the thumb joint. The cross-joint tendon rope is adapted to intersect the first axis when the rotating seat rotates relative to the base to a middle position of a rotating stroke. The application can reduce the length change and tension fluctuation of the cross-joint tendon rope when the wrist metacarpal joint of the thumb rotates.

Description

Technical Field

[0001] This invention relates to the field of rope-driven dexterous hand technology, specifically to a rope-driven dexterous hand thumb motion mechanism, a dexterous hand, and a robot. Background Technology

[0002] A tethered dexterous hand is a humanoid robotic hand that transmits power via tendon cords. Its basic structure includes a palm base and multiple fingers. Each finger is composed of multiple joints connected sequentially, and each joint is connected to a drive assembly via tendon cords. The drive assembly is usually located within the palm base or forearm. The tendon cords originate from the drive assembly, pass through the palm base and reversing elements inside each joint, and are finally fixed to the corresponding phalanx, such as the distal phalanx of the thumb or the distal phalanx of another finger. When the drive assembly pulls on the tendon cords, the tension of the tendon cords is transmitted to the finger joints, driving the joints to flex and extend by traction.

[0003] Of the five fingers, the thumb has the most unique structure. It has three joints: the carpometacarpal joint, the metacarpophalangeal joint, and the interphalangeal joint. The carpometacarpal joint is a saddle-shaped joint, enabling multi-dimensional, wide-range complex movements (including abduction, adduction, flexion, and extension). The metacarpophalangeal and interphalangeal joints primarily enable flexion and extension. Because the thumb performs crucial functions in fine motor operations such as palm opposition and pinching, its movement accuracy and control stability are vital to the overall performance of a dexterous hand.

[0004] The tendons used for the thumb include driving tendons for rotating the thumb's carpometacarpal joint and transarticular tendons for rotating the thumb's metacarpophalangeal and interphalangeal joints. However, the multidimensional and complex oscillating characteristics of the carpometacarpal joint make the transarticular tendons passing through this joint region prone to length changes and tension fluctuations during carpometacarpal joint rotation, thereby interfering with the independent movement of the thumb joint (metacarpophalangeal and / or interphalangeal joints) and creating coupled interference.

[0005] Improving the decoupling performance between the carpal and distal joints without increasing structural complexity is a technical problem that urgently needs to be addressed in this field. Summary of the Invention

[0006] This patent aims to provide a rope-driven movement mechanism for the thumb of a dexterous hand, a dexterous hand, and a robot, to reduce the length change and tension fluctuation of the cross joint tendon rope during thumb wrist-metacarpal joint rotation.

[0007] Through continuous observation, analysis, and experimentation, the applicant aims to identify the reasons why the transarticular tendon of the thumb is prone to length changes and tension fluctuations during wrist-metacarpal joint rotation, as described in the background art. The applicant discovered that when the transarticular tendon passes through the wrist-metacarpal joint region, there is a non-zero perpendicular distance (hereinafter referred to as "offset") between its path and the rotation axis of the wrist-metacarpal joint. When the wrist-metacarpal joint rotates, the spatial orientation of this path changes, causing a change in the effective transmission length of the tendon within the wrist-metacarpal joint region.

[0008] Based on the above, in order to improve the deficiencies of the prior art and achieve the purpose of this invention, the applicant adopts the following technical solution to solve the problem: Technical solution one relates to a rope-driven dexterous thumb movement mechanism, including a base fixed to the palm base and having a first thread guide; a rotating seat fixed to the first metacarpal bone of the thumb and rotatably connected to the base, adapted to be driven to rotate relative to the base about a first axis, including a reversing element; a thumb joint; and at least one cross-joint tendon rope, which extends sequentially through the first thread guide and the reversing element to the thumb joint to drive the thumb joint, adapted to intersect the first axis when the rotating seat rotates relative to the base to the middle position of the rotation stroke. Technical Solution Two, based on Technical Solution One: The cross-joint tendon rope always intersects with the first axis. Technical Solution 3 based on Technical Solution 1: The first guide wire and the reversing component are located on both sides of the first axis; the rotating seat is rotatably connected to the base through the first rotating shaft, and the cross-joint tendon rope passes around the first rotating shaft.

[0009] Technical solution four based on technical solution one: also includes an elastic reset member; the rotating seat is adapted to rotate between a first position and a second position; in the first position, the first metacarpal bone of the thumb is away from the palm base; in the second position, the first metacarpal bone of the thumb is close to the palm base; the two ends of the elastic reset member are respectively connected to the rotating seat and the base, and are adapted to deform and store energy when the rotating seat leaves the first position. Technical Solution 5 based on Technical Solution 4: The elastic reset member is pre-tightened when the rotating seat rotates to the first position; the number of elastic reset members is at least two, and they are symmetrically arranged between the rotating seat and the base along a direction parallel to the first axis. Technical solution six based on technical solution four: the rotation direction of the rotating seat from the first position to the second position is defined as the first rotation direction; a limiting structure is also formed between the rotating seat and the base to restrict the rotating seat from rotating in the first position along a second rotation direction opposite to the first rotation direction. Technical solution seven based on technical solution one: The rotating seat is provided with a first shaft parallel to the first axis; the reversing component is a rotating sleeve sleeved on the first shaft and adapted to rotate relative to the first shaft, the rotating sleeve being made of a self-lubricating material; The first wire guide is provided with a first wire guide hole for the cross joint tendon cable to pass through; the rotating seat is provided with a second wire guide, the second wire guide being provided with a second wire guide hole for the cross joint tendon cable to pass through; both the first and second wire guides are made of self-lubricating material, the end faces at both ends of the first wire guide hole are respectively provided with chamfers, and the end faces at both ends of the second wire guide hole are respectively provided with chamfers; the cross joint tendon cable passes through the first wire guide hole, the reversing member, and the second wire guide hole in sequence. Technical solution eight based on technical solution seven: The rotating seat is driven by a driving tendon rope; the first wire guide is provided with a third wire guide hole for the driving tendon rope to pass through, and the second wire guide is provided with a fourth wire guide hole for the driving tendon rope to pass through; the end faces at both ends of the third wire guide hole are respectively provided with chamfers, and the end faces at both ends of the fourth wire guide hole are respectively provided with chamfers; the rotating seat also includes a seat body and a reversing wheel sleeved on the first shaft and adapted to rotate relative to the first shaft, the first shaft being disposed on the seat body; the driving tendon rope passes through the second wire guide hole, the reversing wheel and the fourth wire guide hole in sequence and is fixedly connected to the seat body.

[0010] The present invention also provides a ninth technical solution, which relates to a rope-driven dexterous hand, including the thumb of the rope-driven dexterous hand as described in any one of technical solutions one to eight. The present invention also provides a tenth technical solution, which relates to a robot including the rope-driven dexterous hand described in the ninth technical solution.

[0011] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects: In technical solution one, "intersecting with the first axis" means that the path of the cross-joint tendon ligament passes through the cylindrical region where the rotation axis corresponding to the first axis is located in space.

[0012] The carpometacarpal joint of the thumb can achieve multi-dimensional, large-range composite swinging. Compared to the metacarpophalangeal joint, which only swings in a small, single direction, its coupling interference is stronger and decoupling is more difficult. The offset between the path of the cross-joint tendon and the first axis is the root cause of the length variation. This solution sets a base (fixed to the palm base) and a rotating seat (fixed to the first metacarpal bone of the thumb), so that the cross-joint tendon extends to the thumb joint through the first thread guide and the reversing member in sequence. It limits the intersection of the cross-joint tendon with the first axis when the rotating seat rotates to the mid-range position. Setting the intersection position (offset of zero) at the mid-range position allows the offset to increase symmetrically when the rotating seat rotates to the extreme on both sides, and the maximum offset throughout the entire stroke is reduced. This reduces the amplitude of the length variation of the cross-joint tendon during the rotation of the carpometacarpal joint, thereby reducing tension fluctuations and the degree of unintended movement of the distal thumb joint caused by tension fluctuations, and improving the controllability of thumb movement.

[0013] Furthermore, this solution can place the path of the tendon rope across the joint near the joint rotation center simply by rationally arranging basic components such as the base, rotating seat, first guide wire, and reversing component. This is an active pre-decoupling rather than post-compensation decoupling. Compared with solutions that require rope length compensation through complex structures, this solution has a simpler structure and lower cost.

[0014] In technical solution two, based on technical solution one, the cross-joint tendon cord is further limited to always intersecting the first axis. This means that the path of the cross-joint tendon cord passes through the first axis throughout the entire rotation, with a constant offset of zero. This fundamentally cancels out the length change caused by the offset. Compared to solutions that achieve zero offset only at a specific position while residual length changes still exist at other positions, this solution maintains zero offset throughout the entire stroke, resulting in a wider decoupling range and higher decoupling accuracy, further reducing the amplitude of length change of the cross-joint tendon cord during wrist and metacarpophalangeal joint rotation.

[0015] In technical solution three, based on technical solution two, the first wire guide and the reversing member are respectively located on both sides of the first axis, and the rotating seat is rotatably connected to the base through the first rotating shaft. The cross-joint tendon rope passes around the first rotating shaft. This arrangement ensures that the cross-joint tendon rope always intersects the first axis. At the same time, the first rotating shaft is used as the constraint point of the cross-joint tendon rope, making the cross-joint tendon rope path more compact and the wiring path simpler and more direct.

[0016] In technical solution four, the elastic reset component deforms and stores energy when the rotating seat leaves the first position. The elastic reset component helps the rotating seat return to the first position, reduces the unexpected displacement caused by the tension fluctuation of the tendon rope across the joint, and improves the passive return performance of the thumb. Compared with the solution that relies on passive traction to return to position, it is beneficial to ensure that the initial reference is consistent for each movement, thereby facilitating the independent and precise control of each degree of freedom of the thumb.

[0017] In Technical Solution Five, based on Technical Solution Four, the elastic reset components are pre-tightened when the rotating seat is in the first position, and there are at least two of them, symmetrically arranged along a direction parallel to the first axis. This further improves the timeliness and consistency of the reset response. The pre-tightening design reduces the swaying of the rotating seat in the first position, and the symmetrical arrangement improves the uniformity of force distribution, thereby enhancing the stability of thumb movement. Compared to solutions with a single elastic reset component or multiple elastic reset components arranged asymmetrically, the symmetrical pre-tightening design of this solution can prevent the rotating seat from wobbling during the reset process, further improving the repeatability and positioning accuracy of thumb movement.

[0018] In technical solution six, the limiting structure restricts unnecessary reverse movement, prevents the rotating seat from exceeding its designed stroke, avoids excessive stretching of the tendon ligaments or interference from internal parts due to over-rotation of the joint, and improves service life. Furthermore, compared to solutions without a dedicated limiting structure that rely solely on rigid restraint by parts, the limiting structure in this solution is easier to implement with flexible and controllable limiting.

[0019] In technical solution seven, the reversing component is a rotating sleeve fitted onto the first shaft and adapted to rotate relative to the first shaft. The rotating sleeve is made of a self-lubricating material. The tendon chords crossing the joint are reversed via the rotating sleeve, improving the frictional characteristics at the reversal point, reducing tension loss caused by friction, increasing transmission response speed, reducing local wear, and extending maintenance cycles. Compared to solutions with fixed reversing components, the rotating sleeve reversing structure in this solution transforms sliding friction into rolling friction, resulting in superior wear reduction and helping to maintain the consistency and stability of tendon chord tension.

[0020] Furthermore, this solution adds a second guide member to the reversing component, forming a three-section wiring structure of "inlet guidance—rotation reversal—outlet constraint". Both the first and second guide members are made of self-lubricating materials and have chamfers, reducing frictional resistance and bending stress when the tendon cord enters and exits the guide hole, and lowering the risk of tendon cord breakage or fraying due to sharp edge scraping. The second guide member provides secondary constraint on the tendon cord at the reversing exit of the reversing component, preventing the tendon cord from shifting or vibrating in the free section after reversal, further improving the certainty and stability of the wiring path. Compared to a solution with only a single reversing component and no outlet constraint, the structure of this solution with double guide members and reversing component can further reduce additional length changes and tension fluctuations caused by the unstable posture of the tendon cord, improving transmission efficiency and service life.

[0021] In technical solution eight, this solution constructs an independent routing path for the drive tendon cable, which is separate from and does not interfere with the routing path of the cross-joint tendon cable. Both the third and fourth cable guide holes are chamfered, reducing frictional resistance and bending stress when the drive tendon cable enters and exits the cable guide holes. The reversing wheel converts the sliding friction between the drive tendon cable and the fixed structure into rolling friction, further improving the transmission efficiency and service life of the drive tendon cable. Compared to solutions where the drive tendon cable and the cross-joint tendon cable share a guide structure or where the drive tendon cable is in direct rigid contact with the seat, this solution, through a four-segment structure of "second cable guide hole guidance—reversing wheel reversal—fourth cable guide hole constraint—end fixing," achieves a low-friction, low-wear, and highly deterministic transmission path for the drive tendon cable, contributing to improved driving accuracy and response speed of the rotating seat.

[0022] Technical solution nine has the technical advantages of any one of technical solutions one through eight.

[0023] Technical solution ten has the technical advantages of technical solution nine. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments are briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the motion mechanism of the rope-driven dexterous thumb in this embodiment. Figure 1 ; Figure 2 This is a schematic diagram of the motion mechanism of the rope-driven dexterous thumb in this embodiment. Figure 2 ; Figure 3 This is a schematic diagram of the hidden part of the motion mechanism of the rope-driven dexterous hand thumb in this embodiment.

[0026] Explanation of key figure labels: Base 10; First wire guide 11; First wire guide hole 111; Third wire guide hole 112; Stop surface 113; First pin 114; Rotating seat 20; Seat body 21; First shaft 211; Stop block 212; Second pin 213; Second wire guide 22; Second wire guide hole 221; Fourth wire guide hole 222; Reversing component 23; Reversing wheel 24; Fixing part 25; First rotating shaft 01; Cross joint tendon rope 30; Drive tendon rope 40; Elastic reset component 50. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are preferred embodiments of the present invention and should not be considered as excluding other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] Unless otherwise expressly defined, the use of terms such as "first," "second," or "third" in the claims, description, and accompanying drawings of this invention is for distinguishing different objects and not for describing a specific order.

[0029] Unless otherwise expressly defined, in the claims, description, and accompanying drawings of this invention, the use of directional terms such as "center," "lateral," "longitudinal," "horizontal," "vertical," "top," "bottom," "inner," "outer," "upper," "lower," "front," "rear," "left," "right," "clockwise," and "counterclockwise" to indicate orientation or positional relationships is based on the orientation and positional relationships shown in the accompanying drawings and is only for the convenience of describing the invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the specific scope of protection of this invention.

[0030] Unless otherwise expressly defined, the terms "fixed connection" or "fixed connection" used in the claims, description and drawings of this invention should be interpreted broadly to refer to any connection in which there is no displacement or relative rotation relationship between the two parties, including non-removable fixed connection, detachable fixed connection, integral connection and fixed connection by other means or components.

[0031] In the claims, description and accompanying drawings of this invention, the terms "comprising," "having," and variations thereof are used to mean "including but not limited to."

[0032] Example This embodiment provides a rope-driven dexterous thumb motion mechanism to improve the coupling interference problem caused by the change in the length of the cross-joint tendon 30 due to the rotation of the wrist and palm joint. The motion mechanism includes a base 10, a rotating seat 20, a thumb joint, at least one cross-joint tendon 30, and an elastic reset member 50.

[0033] The focus of this invention is the motion mechanism of the rope-driven dexterous thumb. The palm base plate and thumb are only used as the mounting carrier and application object of the motion mechanism, and are not improvements of this invention. The palm base plate and thumb are not shown in the drawings.

[0034] See Figure 1-2 , Figure 1-2The diagrams show different angles of the motion mechanism of the rope-driven dexterous hand thumb in this embodiment. The motion mechanism has a base 10 and a rotating seat 20 as its core components. The base 10 is fixedly mounted on the palm base of the dexterous hand, and the rotating seat 20 is fixedly connected to the first metacarpal bone of the thumb and forms a rotatable connection with the base 10 through a first rotating shaft 01. The rotating seat 20 is adapted to be driven to rotate relative to the base 10 to achieve the palmar opposition movement of the thumb. Figure 1-2 In this embodiment, the rotating seat 20 is driven by the driving tendon cord 40, and the cross-joint tendon cord 30 is used to drive the thumb joint to achieve flexion movement. The thumb joint is a metacarpophalangeal joint and / or an interphalangeal joint. This embodiment improves the rope length variation caused by offset by setting a first wire guide 11 on the base 10, setting a reversing member 23 and other wire guide structures on the rotating seat 20, and rationally planning the wire path of the cross-joint tendon cord 30.

[0035] Specifically, the base 10, serving as the mounting foundation for the entire motion mechanism, is fixedly mounted on the palm base plate. See also... Figure 1 A first guide wire 11 is provided on the base 10. The first guide wire 11 is used to guide the cross-joint tendon cord 30 and the drive tendon cord 40 from the palm base or front wall region into the thumb movement mechanism region. In this embodiment, the first guide wire 11 includes a first guide wire hole 111 for the cross-joint tendon cord 30 to pass through and a third guide wire hole 112 for the drive tendon cord 40 to pass through. The first guide wire 11 is made of a self-lubricating material, such as polyoxymethylene, polytetrafluoroethylene, nylon, or ultra-high molecular weight polyethylene. The end faces of the first guide wire hole 111 and the third guide wire hole 112 are respectively chamfered. That is, the inlet and outlet of the first guide wire hole 111 are respectively chamfered, and the inlet and outlet of the third guide wire hole 112 are respectively chamfered. The self-lubricating material and the chamfers help to reduce the frictional resistance and bending stress during the tendon cord passage, and reduce the risk of the tendon cord breaking or fraying due to sharp edge scratches.

[0036] The base 10 also has a shaft hole for mounting the first rotating shaft 01. The base 10 is hinged to the rotating seat 20 through the first rotating shaft 01. The axis of the first rotating shaft 01 is the first axis, and the rotating seat 20 rotates relative to the base 10 around the first axis. To ensure smooth rotation, a bearing or self-lubricating bushing can be provided between the shaft hole and the first rotating shaft 01. Figure 1 The middle part of the first rotating shaft 01 is disconnected to avoid interference with the movement of the drive tendon 40.

[0037] The rotating base 20 has a shaft hole for mounting the first rotating shaft 01, allowing the rotating base 20 to be rotatably connected to the base 10 via the first rotating shaft 01. The rotating base 20 can rotate relative to the base 10 about a first axis. The rotating base 20 has a first position and a second position: in the first position, the first metacarpal bone of the thumb is away from the palm base, and the thumb is in an extended state; in the second position, the first metacarpal bone of the thumb is close to the palm base, and the thumb is in a retracted state. The rotating base 20 can reciprocate about the first axis between the first and second positions. The rotating base 20 is fixedly connected to the first metacarpal bone of the thumb, therefore, the rotation of the rotating base 20 represents the abduction and retraction movement of the thumb's carpal joint. The rotating base 20 integrates various guide structures to meet the routing requirements of different tendons and ligaments.

[0038] See Figure 1 The rotating seat 20 includes a seat body 21, a reversing element 23, and a reversing wheel 24. A first shaft 211 parallel to the first axis is provided on the seat body 21. A rotating sleeve and a reversing wheel 24, which can rotate relative to the first shaft 211, are sleeved on the first shaft 211. The reversing element 23, which is the rotating sleeve, is used for the cross-joint tendon 30 to pass around and achieve reversal; the reversing wheel 24 is used for the drive tendon 40 to pass around and change direction. Both the rotating sleeve and the reversing wheel 24 are made of self-lubricating material, which helps to convert sliding friction into rolling friction, improving the friction characteristics at the reversal and turning points.

[0039] See Figure 2 The rotating seat 20 has a second guide wire 22 on its base 21. The second guide wire 22 guides the cross-joint tendon cord 30 and the drive tendon cord 40 from the rotating seat 20 into the thumb movement mechanism area. The second guide wire 22 has a second guide hole 221 for the cross-joint tendon cord 30 to pass through and a fourth guide hole 222 for the drive tendon cord 40 to pass through. The second guide wire 22 is made of a self-lubricating material, such as polyoxymethylene, polytetrafluoroethylene, nylon, or ultra-high molecular weight polyethylene. The end faces of the second guide hole 221 and the fourth guide hole 222 are both chamfered. That is, the inlet and outlet of the second guide hole 221 and the fourth guide hole 222 are both chamfered. The self-lubricating material and the chamfers help reduce frictional resistance and bending stress during the tendon cord's passage, reducing the risk of broken strands or fraying due to sharp edges.

[0040] See also Figure 2 The seat body 21 is also provided with a fixing part 25 for fixing the drive tendon rope 40. The fixing part 25 is located on the outlet side of the fourth wire hole 222. The drive tendon rope 40 passes through the second wire hole 112, the reversing wheel 24 and the fourth wire hole 222 in sequence and is fixedly connected to the fixing part 25 of the seat body 21.

[0041] See Figure 1The first guide member 11 and the reversing member 23 are located on both sides of the first axis (first rotation axis 01), and the cross-joint tendon cord 30 passes around the first rotation axis 01. In this embodiment, the cross-joint tendon cord 30 passes around the first rotation axis 01 and the reversing member 23 in a manner that is similar to that of the same side. This arrangement helps to keep the routing path of the cross-joint tendon cord 30 intersecting the first axis throughout the entire rotation, thereby maintaining a small offset throughout the entire stroke.

[0042] To limit the rotation range of the rotating seat 20 between the first position and the second position, this embodiment also provides a limiting structure for restricting the rotation range of the rotating seat 20. The direction of rotation of the rotating seat 20 from the first position to the second position is defined as the first rotation direction. Figure 2 (The center is in a clockwise direction), the limiting structure is used to restrict the rotating seat 20 from rotating in a second rotation direction opposite to the first rotation direction in the first position (i.e., continuing to rotate in a direction away from the second position). Figure 2 (Counterclockwise direction in the middle), thus limiting the range of motion of the rotating seat 20 within its designed stroke. See also Figure 2 The limiting structure can be in the form of a stop 212 provided on the rotating seat 20 cooperating with a stop surface 113 provided on the base 10, or it can be in the form of an arc groove provided on the base 10 cooperating with a limiting pin provided on the rotating seat 20.

[0043] It should be understood that, in addition to self-lubricating materials, the rotating sleeve and reversing wheel 24 can also be made of ordinary engineering plastics in combination with grease, or rolling bearings can be installed between the rotating sleeve, reversing wheel 24 and the first shaft 211 to further reduce frictional resistance.

[0044] To drive the rotating seat 20 to reset from the second position to the first position, see [link / reference]. Figure 1 This embodiment also includes an elastic reset member 50, with its two ends connected to the rotating seat 20 and the base 10, respectively, and adapted to deform and store energy when the rotating seat 20 leaves the first position. In this embodiment, the elastic reset member 50 is a tension spring, and the base 10 and the rotating seat 20 are respectively provided with pins for the two ends of the tension spring to hook. Specifically, the base 10 is provided with a first pin 114, and the rotating seat 20 is provided with a second pin 213. One end of the tension spring is hooked onto the first pin 114 of the base 10, and the other end is hooked onto the second pin 213 of the rotating seat 20. When the rotating seat 20 rotates from the first position to the second position, the tension spring is stretched and stores elastic potential energy; when the driving tendon 40 releases the tension, the tension spring releases the elastic potential energy, driving the rotating seat 20 to reset from the second position to the first position. The elastic reset element 50, that is, the tension spring, remains in a stretched state when the rotating seat 20 is in the first position, that is, it has a preload, thereby eliminating transmission backlash and improving motion tracking accuracy.

[0045] In a further optimized scheme, see Figure 2 The number of elastic reset elements 50 (tension springs) is at least two, and they are symmetrically arranged on both sides of the rotating seat 20 along a direction parallel to the first axis. This symmetrical arrangement helps to prevent the rotating seat 20 from wobbling during the reset process, improving the uniformity of force distribution and the smoothness of movement. Compared to schemes with a single elastic reset element 50 or multiple elastic reset elements 50 arranged asymmetrically, the symmetrical preload design of this embodiment helps to further improve the repeatability and positioning accuracy of thumb movement.

[0046] It should be understood that the number of elastic reset elements 50 can be adjusted according to the actual spatial layout and reset torque requirements. It is not limited to two; three or more can also be used, as long as the condition of symmetrical arrangement is met. The elastic reset elements 50 are not limited to tension springs; they can also be in the form of torsion springs, compression springs, or leaf springs, etc. They only need to deform and store energy when the rotating seat 20 leaves the first position and drive the rotating seat 20 to reset when released.

[0047] The following diagram illustrates the routing path using two cross-joint tendon cords 30 and one drive tendon cord 40 as an example. The drive tendon cord 40 is located between the two cross-joint tendon cords 30.

[0048] See Figure 3 , Figure 3 A schematic diagram of the hidden portion of the motion mechanism of the rope-driven dexterous thumb in this embodiment is shown. One end of both the cross-joint tendon rope 30 and the drive tendon rope 40 is connected to a drive assembly, which is disposed within the palm base or forearm. The tendon ropes originate from the drive assembly, pass through a guide channel laid inside the palm base, and first reach the first wire guide 11 on the base 10. The two cross-joint tendon ropes 30 pass through the first wire guide hole 111 and then around the first rotating shaft 01; the drive tendon rope 40 passes through the third wire guide hole 112.

[0049] Subsequently, the cross-joint tendon cord 30, after changing direction by passing around the rotating sleeve (reversing element 23), passes through the second wire hole 221 on the rotating seat 20, extends along the first metacarpal bone of the thumb to the metacarpophalangeal joint and / or interphalangeal joint of the thumb, and connects with the corresponding phalanx. The drive tendon cord 40 then passes around the reversing wheel 24 on the first shaft 211, and then passes through the fourth wire hole 222 on the rotating seat 20, see [reference]. Figure 2 Finally, it is fixed to the fixing part 25 of the seat 21. The driving tendon rope 40 drives the rotating seat 20 to rotate relative to the base 10 and rotate around the first rotating axis 01 by pulling the fixing part 25, thereby realizing the abduction and retraction movement of the thumb wrist joint.

[0050] See also Figure 3The wrap angle of the drive tendon cable 40 around the reversing wheel 24 is smaller than the wrap angle of the cross-joint tendon cable 30 around the reversing member 23. The size of the wrap angle can be adjusted by the position of the wire guide holes on the first wire guide 11 and the second wire guide 22. For example, the third wire guide hole 112 can be made further away from the first shaft 211 relative to the first wire guide hole 111, and the fourth wire guide hole 222 can be made further away from the first shaft 211 relative to the second wire guide hole 221. A smaller wrap angle helps to reduce the frictional resistance between the drive tendon cable 40 and the reversing wheel 24, thereby improving driving efficiency and response speed. A larger wrap angle helps to improve the routing stability and anti-interference ability of the cross-joint tendon cable 30 at the reversing member 23. Through differentiated design, the transmission characteristics of each tendon cable can be optimized within a limited space, avoiding mutual interference.

[0051] In this embodiment, the relationship between the routing path of the cross-joint tendon 30 and the first axis is a key design consideration. When the rotating seat 20 rotates to the mid-range position (i.e., the middle position between the first and second positions), the cross-joint tendon 30 intersects the first axis. That is, the cross-joint tendon 30 extends sequentially through the first guide member 11 and the reversing member 23 to the thumb joint to drive the thumb joint. It is suitable for intersecting the first axis when the rotating seat 20 rotates relative to the base 10 to the mid-range position of the rotation stroke. "Intersecting the first axis" means that the routing path of the cross-joint tendon 30 passes through the cylindrical region where the first rotation axis 01 corresponding to the first axis is located in space. The existence of offset is an important reason for the change in the length of the cross-joint tendon 30 during wrist and palm joint rotation. Setting the position with zero offset at the mid-range position of the rotating seat 20 allows the offset to increase symmetrically when the rotating seat 20 rotates to the extreme positions on both sides, and the maximum offset within the entire stroke is reduced, thereby improving the range of length change of the cross-joint tendon 30 during wrist and palm joint rotation.

[0052] In the preferred embodiment, the cross-joint tendon cord 30 is further defined to always intersect the first axis, meaning that the path of the cross-joint tendon cord 30 passes through the first axis throughout the entire rotation, with a constant offset of zero. This effect is achieved by placing the first guide member 11 and the rotating sleeve (reversing member 23) on opposite sides of the first axis, and by having the cross-joint tendon cord 30 bypass the first rotation axis 01. Since the axis of the first rotation axis 01 is the same as the first axis, the cross-joint tendon cord 30 must pass through the first axis when bypassing it, and this geometric relationship remains unchanged regardless of the angle to which the rotating seat 20 rotates. Therefore, the cross-joint tendon cord 30 can maintain a zero offset throughout its entire stroke, which helps to further reduce the length change caused by the offset and improve the decoupling range and accuracy.

[0053] During operation, the drive assembly pulls the drive tendon cable 40, and the tension of the drive tendon cable 40 is transmitted through the reversing wheel 24, driving the rotating seat 20 to rotate around the first axis from the first position to the second position, thereby driving the thumb to complete the palmar opposition movement. When the wrist and metacarpophalangeal joint rotates, because the routing path of the cross-joint tendon cable 30 has been optimized (passing through the first axis at the mid-range position, and in the preferred scheme, passing through the first axis throughout), the length change of the cross-joint tendon cable 30 is small, the tension fluctuation is effectively suppressed, and the movement of the distal joint of the thumb is less affected by the rotation of the wrist and metacarpophalangeal joint, which helps to improve the decoupling performance between the degrees of freedom.

[0054] When the drive assembly releases the tension of the tendon ligament, the elastic reset member 50 drives the rotating seat 20 to reset from the second position to the first position. The limiting structure restricts the rotating seat 20 to rotate in the first position along a second rotation direction opposite to the first rotation direction, thus completing one complete motion cycle.

[0055] The rope-driven dexterous thumb motion mechanism of this embodiment has the following technical effects: In this embodiment, the carpal joint of the thumb can achieve multi-dimensional, large-range composite swinging. Compared with the small, single-sided swinging of the metacarpophalangeal joint, its coupling interference is stronger and decoupling is more difficult. The offset between the path of the cross-joint tendon 30 and the first axis is the root cause of the length variation. In this embodiment, by setting a base 10 (fixed to the palm base plate) and a rotating seat 20 (fixed to the first metacarpal bone of the thumb), the cross-joint tendon 30 extends to the thumb joint through the first thread guide 11 and the reversing member 23 in sequence, and is limited to intersecting the first axis when the rotating seat 20 rotates to the mid-range position. Setting the intersection position (offset of zero) at the mid-range position allows the offset to increase symmetrically when the rotating seat 20 rotates to the extreme on both sides, and the maximum offset throughout the entire stroke is reduced. This reduces the amplitude of the length variation of the cross-joint tendon 30 during the rotation of the carpal joint, thereby reducing tension fluctuations, reducing the degree of unintended movement of the distal thumb joint caused by tension fluctuations, and improving the controllability of thumb movement.

[0056] Furthermore, this embodiment only requires the reasonable arrangement of basic components such as base 10, rotating seat 20, first wire guide 11 and reversing member 23 to place the wire path of the cross joint tendon rope 30 near the joint rotation center. This is an active pre-decoupling rather than post-compensation decoupling. Compared with the solution that requires rope length compensation through complex structures, this embodiment has a simple structure and is more cost-effective.

[0057] In this embodiment, the cross-joint tendon 30 is further defined to always intersect with the first axis. This means that the path of the cross-joint tendon 30 passes through the first axis throughout the entire rotation, with a constant offset of zero. This fundamentally cancels out the length change caused by the offset. Compared to a scheme that achieves zero offset only at a specific position while residual length changes still exist at other positions, this embodiment maintains zero offset throughout the entire stroke, resulting in a wider decoupling range and higher decoupling accuracy. This further reduces the length change of the cross-joint tendon 30 during wrist and palm joint rotation.

[0058] In this embodiment, the first wire guide 11 and the reversing member 23 are respectively located on both sides of the first axis, and the rotating seat 20 is rotatably connected to the base 10 through the first rotating shaft 01. The cross-joint tendon rope 30 passes around the first rotating shaft 01. This arrangement ensures that the cross-joint tendon rope 30 always intersects the first axis. At the same time, the first rotating shaft 01 is used as the constraint point of the cross-joint tendon rope 30, making the path of the cross-joint tendon rope 30 more compact and the wiring path more concise and direct.

[0059] In this embodiment, the elastic reset member 50 deforms and stores energy when the rotating seat 20 leaves the first position. The elastic reset member 50 helps the rotating seat 20 return to the first position, reduces the unexpected displacement caused by the tension fluctuation of the cross joint tendon 30, and improves the passive return performance of the thumb. Compared with the scheme of relying on passive traction to return to position, it is beneficial to ensure that the initial reference of each movement is consistent, thereby facilitating the independent and precise control of each degree of freedom of the thumb.

[0060] In this embodiment, the elastic reset members 50 are pre-tightened when the rotating seat 20 is in the first position, and there are at least two of them, symmetrically arranged along a direction parallel to the first axis. This further improves the timeliness and consistency of the reset response. The pre-tightening design reduces the swaying of the rotating seat 20 in the first position, and the symmetrical arrangement improves the uniformity of force distribution, thereby enhancing the stability of thumb movement. Compared with a single elastic reset member 50 or an asymmetrical arrangement of multiple elastic reset members 50, the symmetrical pre-tightening design of this embodiment can prevent the rotating seat 20 from swaying during the reset process, further improving the repeatability and positioning accuracy of thumb movement.

[0061] In this embodiment, the limiting structure restricts unnecessary reverse movement, preventing the rotating seat 20 from exceeding its designed stroke, avoiding excessive stretching of the tendon ligament or interference from internal parts due to over-rotation of the joint, and improving service life. Furthermore, compared to solutions without a dedicated limiting structure and relying solely on rigid support from parts, the limiting structure in this embodiment is more conducive to achieving flexible and controllable limiting.

[0062] In this embodiment, the reversing component 23 is a rotating sleeve sleeved on the first shaft 211 and adapted to rotate relative to the first shaft 211. The rotating sleeve is made of a self-lubricating material. The tendon chord 30 of the cross joint is reversed through the rotating sleeve, which improves the frictional characteristics at the reversal point of the tendon chord 30, reduces tension loss caused by friction, improves the transmission response speed, and at the same time reduces local wear and extends the maintenance cycle. Compared with the solution of only setting a fixed reversing component 23, the reversing structure of the rotating sleeve in this embodiment transforms sliding friction into rolling friction, resulting in better wear reduction and helping to maintain the consistency and stability of tendon chord tension.

[0063] In this embodiment, a second guide wire 22 is added to the reversing member 23, forming a three-section wiring structure of "inlet guidance - rotation reversal - outlet constraint". Both the first guide wire 11 and the second guide wire 22 are made of self-lubricating material and have chamfers, which reduces the frictional resistance and bending stress when the cross-joint tendon rope 30 enters and exits the guide hole, and reduces the risk of the cross-joint tendon rope 30 breaking or fraying due to sharp edge scratches. The second guide wire 22 provides secondary constraint on the cross-joint tendon rope 30 at the reversal outlet of the rotating sleeve, avoiding the cross-joint tendon rope 30 from shifting or shaking in the free section after reversal, further improving the certainty and stability of the wiring path. Compared with the scheme of setting only a single reversal structure without outlet constraint, the structure of the double guide wire 22 combined with the rotating sleeve in this embodiment can further reduce the additional length changes and tension fluctuations caused by the unstable posture of the cross-joint tendon rope 30, and improve transmission efficiency and service life.

[0064] This embodiment constructs an independent wiring path for the drive tendon cable 40, which is separate from and does not interfere with the wiring path of the cross-joint tendon cable 30. Both the third wiring hole 112 and the fourth wiring hole 222 are chamfered, reducing the frictional resistance and bending stress of the drive tendon cable 40 when entering and exiting the holes. The reversing wheel 24 converts the sliding friction between the drive tendon cable 40 and the fixed structure into rolling friction, further improving the transmission efficiency and service life of the drive tendon cable 40. Compared to schemes where the drive tendon cable 40 and the cross-joint tendon cable 30 share a guide structure or where the drive tendon cable 40 is in direct rigid contact with the seat 21, this scheme achieves a low-friction, low-wear, and highly deterministic transmission path for the drive tendon cable 40 through a four-segment structure: "guided by the third wiring hole 112—reversing wheel 24—constrained by the fourth wiring hole 222—fixed connection by the fixed part 25," which helps improve the driving accuracy and response speed of the rotating seat 20.

[0065] The present invention also provides a rope-driven dexterous hand, including the above-described rope-driven dexterous hand thumb, which inherits the technical advantages of the above embodiments. The present invention also provides a robot, including the above-described rope-driven dexterous hand, which inherits the technical advantages of the above embodiments.

[0066] The foregoing description of the specifications and embodiments is intended to explain the scope of protection of this invention, but does not constitute a limitation on the scope of protection of this invention. Modifications, equivalent substitutions, or other improvements to the embodiments of this invention or a portion thereof that can be obtained by those skilled in the art through logical analysis, reasoning, or limited experimentation, based on the teachings of this invention or the foregoing embodiments, in conjunction with common knowledge, general technical knowledge, and / or existing technology, should all be included within the scope of protection of this invention.

Claims

1. A rope-driven dexterous thumb motion mechanism, characterized in that, include The base (10) is fixed to the palm base plate and is provided with a first wire guide (11); A rotating seat (20), which is fixed to the first metacarpal bone of the thumb and rotatably connected to the base (10), is adapted to be driven to rotate relative to the base (10) about a first axis, and includes a reversing element (23); thumb joint; and At least one transarticular tendon cord (30) extends sequentially through the first guide member (11) and the reversing member (23) to the thumb joint to drive the thumb joint, and is adapted to intersect the first axis when the rotating seat (20) rotates relative to the base (10) to the midpoint of the rotation stroke.

2. The rope-driven dexterous thumb motion mechanism as described in claim 1, characterized in that, The transarticular tendon cord (30) always intersects with the first axis.

3. The rope-driven dexterous thumb movement mechanism as described in claim 2, characterized in that, The first guide wire (11) and the reversing member (23) are located on both sides of the first axis; the rotating seat (20) is rotatably connected to the base (10) through the first rotating shaft (01), and the cross joint tendon rope (30) passes around the first rotating shaft (01).

4. The rope-driven dexterous thumb motion mechanism as described in claim 1, characterized in that, It also includes an elastic reset member (50); the rotating seat (20) is adapted to rotate between a first position and a second position; In the first position, the first metacarpal bone of the thumb is away from the base of the palm. In the second position, the first metacarpal bone of the thumb is close to the base of the palm. The two ends of the elastic reset member (50) are respectively connected to the rotating seat (20) and the base (10), and are adapted to deform and store energy when the rotating seat (20) leaves the first position.

5. The rope-driven dexterous thumb movement mechanism as described in claim 4, characterized in that, The elastic reset member (50) is pre-tightened when the rotating seat (20) rotates to the first position; the number of elastic reset members (50) is at least two, and they are symmetrically arranged between the rotating seat (20) and the base (10) in a direction parallel to the first axis.

6. The rope-driven dexterous thumb motion mechanism as described in claim 4, characterized in that, The rotation direction of the rotating seat (20) from the first position to the second position is defined as the first rotation direction; a limiting structure is also formed between the rotating seat (20) and the base (10) to restrict the rotating seat (20) from rotating in the first position along a second rotation direction opposite to the first rotation direction.

7. The rope-driven dexterous thumb motion mechanism as described in claim 1, characterized in that, The rotating seat (20) is provided with a first shaft (211) parallel to the first axis; the reversing member (23) is a rotating sleeve sleeved on the first shaft (211) and adapted to rotate relative to the first shaft (211), the rotating sleeve being made of a self-lubricating material; the first thread guide (11) is provided with a first thread hole (111) for the cross-joint tendon rope (30) to pass through; the rotating seat (20) is provided with a second thread guide (22), the second thread guide (22) being provided with a second thread hole (221) for the cross-joint tendon rope (30) to pass through; both the first thread guide (11) and the second thread guide (22) are made of self-lubricating material, the end faces at both ends of the first thread hole (111) are respectively provided with chamfers, and the end faces at both ends of the second thread hole (221) are respectively provided with chamfers; the cross-joint tendon rope (30) passes through the first thread hole (111), the reversing member (23), and the second thread hole (221) in sequence.

8. The rope-driven dexterous thumb motion mechanism as described in claim 7, characterized in that, The rotating seat (20) is driven by a drive tendon rope (40); the first wire guide (11) is provided with a third wire guide hole (112) for the drive tendon rope (40) to pass through, and the second wire guide (22) is provided with a fourth wire guide hole (222) for the drive tendon rope (40) to pass through; the end faces of the third wire guide hole (112) and the end faces of the fourth wire guide hole (222) are respectively provided with chamfers; the rotating seat (20) also includes a seat body (21) and a reversing wheel (24) sleeved on the first shaft (211) and adapted to rotate relative to the first shaft (211), the first shaft (211) is provided on the seat body (21); the drive tendon rope (40) passes through the second wire guide hole (112), the reversing wheel (24) and the fourth wire guide hole (222) in sequence and is fixedly connected to the seat body (21).

9. A rope-driven dexterous hand, characterized in that, Including the motion mechanism of the rope-driven dexterous hand thumb as described in any one of claims 1-8.

10. A robot, characterized in that, Including the rope-driven dexterous hand as described in claim 9.

Images