Wire passing structure, robotic finger tendon drive system and control method

Abstract

The application discloses a wire passing structure, a robot finger tendon rope transmission system and a control method. The first side tendon rope of the wire passing structure enters a proximal joint inner driving channel through a first fixed wire passing point, abuts against or bypasses a follow-up support part, passes through the first wire passing point, and continuously extends to a distal joint. The second side tendon rope enters the proximal joint inner driving channel from a second wire passing point, abuts against or bypasses a fixed support part, passes through the second fixed wire passing point, and continuously extends to a driving unit. The application is coupled with a double-motor driving unit control scene, so that when the distal tendon rope crosses the proximal area, the common mode length change of the first side and the second side tendon ropes caused by the rotation of the proximal joint can be set in a small range, the pre-tightening force is more stable, the differential mode length change is compensated by the motor mode, and the pre-tightening fluctuation is not directly converted into the spring pre-tightening, so that the double-motor control difficulty can be reduced.

Description

Technical Field

[0001] This invention relates to the field of robotics, specifically to a wire-passing structure, a robot finger tendon ligament transmission system, and a control method. Background Technology

[0002] Robotic dexterous hands often employ chord drives to reduce the mass at the fingertips, and place motors in the palm, forearm, or other locations with ample space. For a single finger joint or multiple joints, a dual-motor drive unit can provide more flexible control than a single motor: the combined motion of the same set of dual motors can be used to drive the joint, while the relative motion of the same set of dual motors can be used to adjust the chord preload or the equivalent stiffness of the system.

[0003] However, in multi-jointed fingers, the chordae tendons used for the distal joints typically need to cross the area near the proximal joint and continue extending to the distal joint or load wheel. Rotation of the proximal joint or proximal link alters the path length of these distal chordae tendons. If this length change acts simultaneously on both chordae tendons in a common-mode manner, it causes both springs to stretch or shorten simultaneously, resulting in significant fluctuations in preload with the joint angle. Relying solely on controller compensation increases the difficulty of dual-motor control and may lead to motor torque fluctuations, decreased joint following performance, or unstable chordae tension.

[0004] In view of the above-mentioned defects, the inventors of this invention have finally obtained this invention after a long period of research and practice. Summary of the Invention

[0005] To address the aforementioned technical deficiencies, the present invention provides a wire-passing structure, wherein the wire-passing structure extends from the proximal joint of the robot finger to the distal joint after the drive unit passes over it. The cable-passing structure includes a first lateral tendon cord, a second lateral tendon cord, a fixed support portion, a follower support portion, a first cable-passing point, and a second cable-passing point. The drive unit connects the first lateral tendon cord and the second lateral tendon cord within the same drive channel. The fixed support portion and the follower support portion are both disposed on the drive channel within the proximal joint. The fixed support portion is a circular groove or rounded corner that is fixed relative to the proximal joint, and the follower support portion is a circular groove or rounded corner that moves with the proximal joint. The first cable-passing point and the second cable-passing point are rigidly associated with the proximal joint. The first lateral tendon cord enters the proximal joint drive channel via the first fixed thread crossing point, and after abutting or bypassing the follower support, it continues to extend to the distal joint, distal load wheel, or corresponding distal tendon cord path after passing through the first thread crossing point; the second lateral tendon cord enters the proximal joint drive channel from the second thread crossing point, and after abutting or bypassing the fixed support, it continues to extend to the motor wheel, drive unit, or other thread crossing structure after passing through the second fixed thread crossing point. The fixed support, the follower support, the first fixed cross-line point, the second fixed cross-line point, the first cross-line point, and the second cross-line point are configured such that the common modulus length change of the first and second lateral tendon chord paths caused by proximal joint rotation satisfies a predetermined condition. The predetermined conditions for the common mode length change are: the maximum absolute value of the common mode length change is less than a predetermined absolute threshold; or less than a predetermined proportion of the larger of the maximum absolute value of the length change of the first side tendon cord's path and the maximum absolute value of the length change of the second side tendon cord's path; or, when a spring is connected in series with the tendon cord path, less than a predetermined proportion of the spring's allowable working elongation.

[0006] Preferably, a robotic finger tendon cord transmission system employs the aforementioned cord-passing structure, wherein the first side tendon cord and the second side tendon cord are provided with springs and limiting portions that cooperate with the springs.

[0007] Preferably, the drive unit adopts a dual-motor drive unit, and each drive unit includes a first motor and a second motor. The first motor and the second motor are respectively associated with their respective first lateral tendon ropes and second lateral tendon ropes. The first lateral tendon ropes and the second lateral tendon ropes are driven by the motor wheel corresponding to the same first motor or the second motor, and are wound in opposite directions on the same motor wheel. The joint movement of the first motor and the second motor forms a joint drive mode, and the relative movement of the first motor and the second motor forms a preload mode or a spring-limited retention mode.

[0008] Preferably, the spring and the limiting part that cooperates with the spring are connected in series in the tendon paths corresponding to the first side tendon and the second side tendon. When the spring extends to the limiting position, the limiting part contacts the spring and bears the subsequent load, thereby increasing the equivalent stiffness of the corresponding tendon path.

[0009] Preferably, the tendon tension T of the tendon cord on the first side or the second side where the spring and the limiting part are located is:

[0010]

[0011] in, This is the spring elongation. This is the initial preload elongation of the spring. The spring elongation increment from the initial preloaded state to the limit position is: , Let be the elastic stiffness of the spring. This is the equivalent additional stiffness after the spring is limited.

[0012] Preferably, the equivalent center of the follower support, the first cross-line point, and the second cross-line point all rotate around the same fixed reference point on the proximal joint.

[0013] Preferably, the fixed reference point is located on the axis of the fixed support.

[0014] Preferably, a control method for a robotic finger tendon chord transmission system includes the following steps: S1, read the proximal joint angle, the distal joint angle, and the motor angles of the two motors on the same drive unit; S2, calculate the length changes of the passage paths of the first side tendon rope and the second side tendon rope according to the geometric model of the passage structure; S3, calculate the differential mode length change and common mode length change caused by the through-wire structure; S4, calculate the joint driving mode based on the desired proximal / distal joint angle; S5, calculate the preload mode based on the target spring elongation or the limit retention target; S6, superimposes the differential mode compensation of the line-crossing structure onto the corresponding motor's drive mode; S7, the target angle or target speed of the two motors on the same drive unit is obtained by modal inversion transformation; S8 performs closed-loop control of the position, speed, or torque of the corresponding motor.

[0015] Preferably, in step S2, The length of the path of the first lateral tendon cord changes as follows:

[0016] The length of the path of the second lateral tendon cord changes as follows:

[0017] in, The first lateral tendon chord path at the proximal joint angle is The length of time; The second lateral tendon tract path at the proximal joint angle is The length of time; This serves as a reference joint angle for calculating length variations; The first lateral tendon chord path at the proximal joint angle is The length of time; The second lateral tendon tract path at the proximal joint angle is The length of time; The first lateral tendon ligament path is... To reference joint angle The length change; For the second lateral tendon tract path by To reference joint angle The length changes.

[0018] Preferably, in step S3, Differential mode length variation The calculation formula is:

[0019] Common mode length variation The calculation formula is: .

[0020] Preferably, the motor angle of the first motor is set as follows: The motor angle of the second motor ; In step S4, the driving mode of the joint The expression is:

[0021] In step S5, the pre-tightening mode of the joint The expression is:

[0022] In step S7, the inverse transformation expression is:

[0023] .

[0024] Preferably, in step S6, the differential mode compensation of the through-line structure is performed. The expression is:

[0025] in, To compensate for differential mode gain; Let be the radius of the motor wheel.

[0026] Preferably, the common mode length variation satisfies the setting conditions by setting the equivalent radius of the fixed support, the equivalent radius of the follower support, the distance between the equivalent centers of the fixed support and the follower support, the first fixed cross-line point, the second fixed cross-line point, the first cross-line point, the second cross-line point, and the position of the equivalent center of the follower support.

[0027] Preferably, the common mode length variation is set under the following conditions: the maximum absolute value of the common mode length variation is less than a predetermined absolute threshold; or less than a predetermined proportion of the larger of the maximum absolute value of the length variation of the first side tendon rope's path and the maximum absolute value of the length variation of the second side tendon rope's path; or less than a predetermined proportion of the spring's allowable working elongation.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: The coupling design of the present invention for the control scenario of the wire-passing structure and the dual-motor drive unit enables the change of common modulus length of the first and second side tendons caused by the rotation of the proximal joint when the distal tendon cord crosses the proximal region. The change of common modulus length can be set within a small range, and the preload is more stable. The change of differential modulus length is compensated by the motor mode and is not directly converted into spring preload fluctuation, which can reduce the difficulty of dual-motor control. Attached Figure Description

[0029] Figure 1 A schematic diagram showing the installation of the robot finger tendon cable transmission system on the robot finger; Figure 2 This is a schematic diagram of the structure of the over-wire structure within the proximal joint; Figure 3 A diagram showing the length changes of the first and second tendon chords as the distal tendon chords cross the proximal region, resulting from the rotation of the proximal joint. Figure 4 This is a schematic diagram of the structure of the spring and the limiting part.

[0030] The numbers in the diagram represent: 1-Proximal joint; 2-Distal joint; 3-Drive unit; 4-First lateral tendon ligament; 5-Second lateral tendon ligament; 6-Fixed support; 7-Follow-up support; 8-First thread-passing point; 9-Second thread-passing point; 10-First fixed thread-passing point; 11-Second fixed thread-passing point; 12-Spring; 13-Limiting part; 31-First motor; 32-Second motor; 33-Motor wheel. Detailed Implementation

[0031] The above-mentioned and other technical features and advantages of the present invention will be described in more detail below with reference to the accompanying drawings. Example 1

[0032] like Figure 1 and Figure 2 As shown, Figure 1 A schematic diagram showing the installation of the robot finger tendon cable transmission system on the robot finger; Figure 2 This is a schematic diagram of the structure of the over-wire structure within the proximal joint.

[0033] The present invention discloses a robot finger tendon cable transmission system for use in a robot finger. The robot finger includes a proximal joint 1 and a distal joint 2. The robot finger tendon cable transmission system includes a cable-passing structure that extends from the proximal joint 1 to the distal joint 2. The proximal joint 1 can be driven by a synchronous belt, gear, linkage, or other transmission method, and the distal joint 2 is driven by the cable-passing structure.

[0034] The cable-passing structure includes a drive unit 3, a first side tendon rope 4, a second side tendon rope 5, a fixed support part 6, a follower support part 7, a first cable-passing point 8, and a second cable-passing point 9. Each drive unit 3 is connected to the first side tendon rope 4 and the second side tendon rope 5 in the same drive channel through a corresponding motor wheel 33. The first side tendon rope 4 and the second side tendon rope 5 are driven by the same drive unit 3 and are wound in opposite directions on the same motor wheel 33. The fixed support part 6 is a circular groove or rounded corner that is fixed relative to the proximal joint 1 in the drive channel within the proximal joint 1. The follower support part 7 is a circular groove or rounded corner that moves with the proximal joint 1 in the drive channel within the proximal joint 1. The first cable-passing point 8 and the second cable-passing point 9 are rigidly associated with the proximal joint 1. The first side tendon rope 4 and the second side tendon rope 5 are provided with a spring 12 and a limiting part 13 that cooperates with the spring 12.

[0035] The first lateral tendon rope 4 enters the drive channel within the proximal joint 1 via the first fixed cable passing point A10, and after abutting or bypassing the follower support 7, passes through the first cable passing point E8 and continues to extend to the distal joint 2, the distal load wheel, or the corresponding distal tendon rope path; the second lateral tendon rope 5 enters the drive channel within the proximal joint 1 from the second cable passing point F9, and after abutting or bypassing the fixed support 6, passes through the second fixed cable passing point B11 and continues to extend to the motor wheel 33, the drive unit, or other cable passing structures.

[0036] Specifically, the drive unit 3 adopts a dual-motor drive unit 3. Each group of drive units 3 includes a first motor 31 and a second motor 32. Each motor is connected to the first lateral tendon rope 4 and the second lateral tendon rope 5 in the same drive channel through a corresponding motor wheel 33. The first lateral tendon rope 4 and the second lateral tendon rope 5 are driven by the same motor and can be wound in opposite directions on the same motor wheel 33. The first lateral tendon rope 4 and the second lateral tendon rope 5 are used to generate joint torques in different directions or form a set of antagonistic transmission paths.

[0037] At least a portion of the tendon cords used for the distal joint 2 crosses the area near the proximal joint 1 and continues to act on the distal joint 2 or the distal load wheel. The proximal joint 1 can be driven by a timing belt, gears, linkages, or other transmission methods. Generally, in specific embodiments, the first side tendon cord 4 and the second side tendon cord 5 correspond to the palm-side tendon cord and the back-side tendon cord, respectively.

[0038] The equivalent center of the fixed support 6 is denoted as D, and the equivalent radius is denoted as R. The equivalent center of the follower support 7 is denoted as C, and the equivalent radius is denoted as r. L is the distance between the center C and the center D. The first crossing point E8 and the second crossing point F9 are not the endpoints of the tendon cord, but rather points along the distal tendon cord path. The spring 12 and the limiting part 13 that cooperates with the spring 12 are connected in series in the tendon cord path.

[0039] The equivalent center C of the follower support 7, the first guide point E8, and the second guide point F9 can be represented as rotations around a reference point D; in the actual structure, D can coincide with the axis of the proximal joint 1, or it can be a reference point used for equivalent calculations. The first fixed guide point A10 and the second fixed guide point B11 can be set on the palm-side base, frame, or proximal support.

[0040] The fixed support 6 and the follower support 7 are not limited to rotatable guide wheels. They can also be approximately circular grooves, rounded corners, arc surfaces, low-friction bushings, rollers, pulleys, or other structures that can provide an equivalent arc contact path, as long as they form an equivalent arc contact path for the tendon ligament and satisfy the geometric relationship of low common mode variation.

[0041] In one simulation embodiment, the coordinates of the fixed reference point A can be taken as follows: The coordinates of the fixed reference point B can be taken as follows: The equivalent center D of the fixed circular groove or fixed fillet can be taken as... The initial vector of the equivalent center C of the moving circular groove or moving fillet relative to D can be taken as... The initial direction of CD is approximately 225° and the distance is approximately 5mm. The initial vectors of points E and F relative to D can be taken as follows: and The equivalent radius r of the moving circular groove or moving fillet can be taken as 1mm, and the equivalent radius R of the fixed circular groove or fixed fillet can be taken as 3mm.

[0042] In the above simulation embodiment, the first-side tendon cord 4 enters from fixed point A, adheres to the moving circular groove or moving rounded corner along the preset tangential side and arc direction, and then passes through point E; the second-side tendon cord 5 enters from point F, adheres to the fixed circular groove or fixed rounded corner along the preset tangential side and arc direction, and then reaches fixed point B. By scanning the joint angle within the working angle range of the proximal joint 1, the changes in the length of the first-side path, the length of the second-side path, the differential mode length, and the common mode length of the distal tendon cord can be obtained, and the suppression effect of the through-line structure on preload fluctuation can be evaluated accordingly.

[0043] This invention addresses the coupling design of the wire-passing structure and the dual-motor drive unit 3 control scenario. When the distal tendon ligament crosses the proximal region, the change in the common mode length of the first and second side tendon ligaments 5 caused by the rotation of the proximal joint 1 can be controlled. The change in the common mode length can be set within a small range, resulting in a more stable preload. The change in the differential mode length is compensated by the motor mode, rather than being directly converted into preload fluctuations of the spring 12. This reduces the difficulty of dual-motor control and is suitable for robot fingers with significant coupling between the proximal joint 1 and the distal joint 2. Example 2

[0044] A robotic finger may include four motors, each connected to two tendon cords, thus forming a total of eight tendon cords. The two tendon cords connected to each motor can serve as the first side tendon cord 4 and the second side tendon cord 5 within the same drive channel, and are wound in opposite directions on the motor wheel 33 of that motor. The four motors can be grouped into two dual-motor drive units 3, with each dual-motor drive unit 3 forming a joint drive mode through the joint movement of the two motors, and forming a preload mode through the relative movement of the two motors.

[0045] Let the proximal joint angle be... Reference angle is The two-dimensional rotation matrix is:

[0046] If the initial vectors of C, E, and F relative to D in the geometrically equivalent model are... , , ,but:

[0047]

[0048]

[0049] For any circular groove or fillet, let the center be O and the radius be... If the external point is P, then the angle of the tangent point can be determined by: The vector from the center O to the outer point P: ; The distance from external point P to the center O of the circle: ; vector Offset angle of the direction angle to the tangent point: ; From the direction angle Offset angle of the direction angle to the tangent point: ; The central angle corresponding to the point of tangency: ; The coordinates of the tangent point are:

[0050] A tendon rope from After attaching to the circular groove or rounded corner The length is:

[0051] in and The two ends are tangent. This refers to the central angle of the arc where the tendon ligament actually rests. In an actual structure, the tendon ligament cannot jump to the other side of the arc during movement; therefore, the bypass branch should be fixed, rather than re-selecting the shortest path at each angle.

[0052] Preferably, the controller or simulation model pre-sets the tangential side for entering the arc, the tangential side for leaving the arc, and the arc contact direction for each tendon path. The tangential side and the arc contact direction remain unchanged during joint movement to correspond to the actual state of the tendon moving along a fixed branch under the constraint of the channel, fillet, edge, or guide structure.

[0053] like Figure 3 As shown, Figure 3 This diagram shows the length changes of the first and second chordae tendons as the distal tendon crosses the proximal region, resulting from proximal joint rotation. The diagram illustrates the length change of the first chordae tendon. Changes in length on the second side Differential mode length variation and common mode length variation .

[0054] Define the length variation of the path of the first lateral tendon 4 as follows:

[0055] Define the length variation of the path of the second lateral tendon 5 as follows:

[0056] The change in differential mode length caused by the aforementioned through-line structure is:

[0057] The common-mode length changes as follows:

[0058] This invention can be achieved by selecting R, r, L, A, B, , , The initial installation angle ensures that when the distal tendon ligament crosses the proximal region, it is within the working range of the proximal joint 1. The absolute value is relatively small. In this way, the rotation of the proximal joint 1 will not significantly change the common elongation of the springs 12 on both sides of the distal tendon chord, which helps to maintain the stability of the preload.

[0059] In different embodiments, the small variation in the common mode length can be expressed as follows: within the working angle range of the proximal joint 1, The maximum absolute value is less than a predetermined absolute threshold; or less than a predetermined proportion of the larger of the maximum absolute value of the length change of the path of the first side tendon rope 4 and the maximum absolute value of the length change of the path of the second side tendon rope 5; or less than a predetermined proportion of the allowable working elongation of the spring 12.

[0060] Through geometric parameter design, It is relatively small within the working angle range; Modal control compensation can be achieved by the dual-motor drive unit 3. The aforementioned predetermined ratio can be determined based on finger size, spring stiffness, preload range, and control accuracy requirements. Example 3

[0061] The spring 12 can be connected in series in each tendon path. The spring 12 is used to absorb minor displacements caused by tendon length errors, finger structure errors, and external contact. The spring 12 is provided with a corresponding limiting part 13. When the spring 12 extends to a set length, the limiting part 13 contacts the spring 12 and bears the subsequent load, thereby increasing the equivalent stiffness of the tendon path.

[0062] like Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of the spring and the limiting part; let the spring elongation be... The initial preload elongation of the spring is The spring elongation increment from the initial preloaded state to the limit position is The elastic stiffness of the spring is The equivalent additional stiffness after the spring is limited is Where T is the tension of the tendon chord; then it can be approximated by the following formula:

[0063]

[0064] in Greater than This structure gives the system compliance when the limit is not reached, and high transmission stiffness when the limit is reached.

[0065] In one embodiment, the tension after the spring 12 is stopped can also be expressed as:

[0066] in This expression indicates that when the spring elongation does not exceed the limit position, the additional stiffness term does not participate; when the spring elongation exceeds the limit position, the limiting structure bears the subsequent load and forms additional stiffness.

[0067] The spring 12 described in this invention can compensate for rope length errors and contact disturbances, while the limiting part 13 provided corresponding to the spring 12 can provide an approximately rigid connection when high stiffness is required. Example 4

[0068] For the first motor 31 and the second motor 32 included in the drive unit 3, let the motor angle of the first motor 31 be... The motor angle of the second motor 32 Therefore Joint driving modes : Used to drive the movement of proximal joint 1 or distal joint 2, its expression is:

[0069] Joint preload mode : Used to adjust the relative output between the two motors in the dual-motor drive unit 3, thereby adjusting the pretension state of the tendon rope assembly, or keeping spring 12 close to the limit position, its expression is:

[0070] The inverse transformation is:

[0071]

[0072] Let the proximal joint angle be... The distal joint angle is The near-end equivalent radius is The far-end equivalent radius is The radius of motor wheel 33 is When the tendon cord of a certain set of distal dual-motor drive units 3 crosses the proximal joint 1 and acts on the distal joint 2, the load-side length term can be defined:

[0073] The joint drive modes of the remote dual-motor drive unit 3 may include:

[0074] in This is a compensation term for the cross-line structure.

[0075] Because the wiring structure used in this invention minimizes the change in common-mode length, the controller primarily compensates for the change in differential-mode length.

[0076] in, This is for differential mode compensation gain. When When, the differential mode length variation is fully compensated according to the geometric model; when When the value is less than 1 or greater than 1, it can be used to compensate for model errors, friction, or actual assembly errors.

[0077] After compensation, the remaining common changes of the first lateral tendon cord 4 and the second lateral tendon cord 5 caused by the overpass structure are mainly as follows: Since the common mode term is reduced through structural design, the preload of spring 12 fluctuates less.

[0078] The controller can directly measure the spring elongation, or estimate the spring elongation, tendon tension, and spring 12 state based on the motor encoder, joint encoder, and structural model. When it is necessary to maintain the spring 12 at its limit, the controller uses a preload mode. The specified tendon spring 12 is extended to near the limit or pressed against the limit, and this state is maintained by the torque of the limited motor. Example 5

[0079] The control method for the robot finger tendon chord transmission system of the present invention, using the robot finger tendon chord transmission system, includes the following steps: S1, read the proximal joint angle, distal joint angle, and motor angles of the two motors on the same drive unit 3; S2, calculate the length change of the passage path of the first side tendon rope 4 and the length change of the passage path of the second side tendon rope 5 according to the geometric model of the passage structure. S3, calculate the differential mode length change and common mode length change caused by the through-wire structure; S4, calculate the joint driving mode based on the desired proximal / distal joint angle; S5, calculate the preload mode based on the target elongation of spring 12 or the limit retention target; S6, superimposes the differential mode compensation of the line-crossing structure onto the corresponding motor's drive mode; S7, the target angle or target speed of the two motors on the same drive unit 3 is obtained by modal inversion transformation; S8 performs closed-loop control of the position, speed, or torque of the corresponding motor.

[0080] Specifically, in step S2, The length of the path of the first lateral tendon 4 changes as follows:

[0081] The length of the path of the second lateral tendon 5 changes as follows:

[0082] in, The first lateral tendon 4 path is at the proximal joint angle as The length of time; The second lateral tendon 5 path is at the proximal joint angle as The length of time; This serves as a reference joint angle for calculating length variations; The first lateral tendon 4 path is at the proximal joint angle as The length of time; The second lateral tendon 5 path is at the proximal joint angle as The length of time; The first lateral tendon rope 4 path is from To reference joint angle The length change; The second lateral tendon 5 path is from To reference joint angle The length changes.

[0083] In step S3, Differential mode length variation The calculation formula is:

[0084] Common mode length variation The calculation formula is: .

[0085] Preferably, the motor angle of the first motor 31 is set as follows: The motor angle of the second motor 32 ; In step S4, the driving mode of the joint The expression is:

[0086] In step S5, the pre-tightening mode of the joint The expression is:

[0087] In step S7, the inverse transformation expression is:

[0088] .

[0089] Preferably, when the tendon cord within the drive unit 3 corresponding to the distal joint 2 crosses the proximal joint 1 and acts on the distal joint 2, the expression for the load-side length term is:

[0090] in, The equivalent arm or equivalent radius of the tendon chord corresponding to the proximal joint; The equivalent force arm or equivalent radius of the tendon chord corresponding to the distal joint; The radius of the motor wheel, For the proximal joint angle, The distal joint angle.

[0091] For the remote dual-motor drive unit 3, its joint drive modes include:

[0092] in, The target quantity of the driving mode of the dual-motor drive unit 3 acting on the distal joint 2, This is a compensation term for the cross-line structure.

[0093] Preferably, in step S6, the differential mode compensation of the through-line structure is performed. The expression is:

[0094] in, This is the differential mode compensation gain, used to adjust the geometric compensation amount; when When, the differential mode length variation is fully compensated according to the geometric model; when When the value is less than 1 or greater than 1, it can be used to compensate for model errors, friction, or actual assembly errors.

[0095] The control method of the robot finger tendon cable transmission system described in this invention, compared with the existing ordinary tendon cable passing structure and simple control compensation method, includes a structural compensation term and is not a simple motor angle PID or ordinary modal control. Example 6

[0096] In this embodiment, a four-motor, eight-wire rope configuration is used, with the angles of the four motors set as follows: , , , Each motor corresponds to two reverse-winding tendon ropes. Therefore, the change in the winding length of the eight tendon ropes caused by the motor wheel 33 can be expressed as:

[0097] Among them, the root tendon rope and the first The root tendon rope is from the first Two motors drive the winding length, and the signs of their changes are opposite. Four motors can be operated according to (…). )and( It is divided into two groups of dual-motor drive units, and the joint drive mode and pre-tightening mode are decomposed respectively.

[0098] In a specific embodiment, the robotic finger further includes a cable guide groove, a oscillating cable guide element, or a guide radius driven by a servo motor or other actuator. The cable guide groove is used to allow the tendon chord to pass as close as possible to the axis of rotation of the servo motor or oscillating element, thereby reducing the change in tendon chord length caused by servo motor rotation. The angle of this cable guide groove is denoted as... When passing through the wire groove The length of the residual tendon rope path may still change with rotation or oscillation. Let the change in the additional length of the left servo motor passing through the cable groove be... The change in the additional length of the right-side servo motor through the cable tray is as follows: The changes in the lateral lengths of the eight tendon ropes can be expressed as follows:

[0099] in The term representing the equivalent chord length caused by the proximal joint angle can be taken as... ; acceptable ; The change in length on the first side is caused by the distal tendon chord crossing the proximal region through the chordal structure. This refers to the change in length on the second side caused by the distal tendon chord crossing the proximal region via the cable passage structure. When calculating the spring elongation, tendon chord tension, and motor target angle, the controller can simultaneously consider the motor winding length, the change in length of the cable passage structure across the proximal region, the length term on the joint load side, and the additional length change of the servo motor cable passage slot.

[0100] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, all of which will fall within the protection scope of the present invention.

Claims

1. A wire-passing structure, wherein the wire-passing structure extends from the proximal joint of a robot finger to the distal joint via a drive unit; characterized in that, The device includes a first lateral tendon cord, a second lateral tendon cord, a fixed support portion, a follower support portion, a first guide point, and a second guide point. The drive unit connects the first lateral tendon cord and the second lateral tendon cord within the same drive channel. The fixed support portion and the follower support portion are both disposed on the drive channel within the proximal joint. The fixed support portion is a circular groove or rounded corner that is fixed relative to the proximal joint, and the follower support portion is a circular groove or rounded corner that moves with the proximal joint. The first guide point and the second guide point are rigidly associated with the proximal joint. The first lateral tendon cord enters the proximal joint drive channel via the first fixed crossing point, and after abutting or bypassing the follower support, passes through the first crossing point and continues to extend to the distal joint; the second lateral tendon cord enters the proximal joint drive channel from the second crossing point, and after abutting or bypassing the fixed support, passes through the second fixed crossing point and continues to extend to the drive unit. The fixed support, the follower support, the first fixed cross-line point, the second fixed cross-line point, the first cross-line point, and the second cross-line point are configured such that the common modulus length change of the first and second lateral tendon chord paths caused by proximal joint rotation satisfies a predetermined condition. The predetermined conditions for the common mode length change are: the maximum absolute value of the common mode length change is less than a predetermined absolute threshold; or less than a predetermined proportion of the larger of the maximum absolute value of the length change of the first side tendon cord's path and the maximum absolute value of the length change of the second side tendon cord's path; or, when a spring is connected in series with the tendon cord path, less than a predetermined proportion of the spring's allowable working elongation.

2. A robotic finger tendon cable transmission system, characterized in that, The cable-passing structure as described in claim 1 includes a spring and a limiting part that cooperates with the spring on the first and second side tendon ropes.

3. The robotic finger tendon cable transmission system as described in claim 2, characterized in that, The drive unit adopts a dual-motor drive unit. Each drive unit includes a first motor and a second motor. The first motor and the second motor are respectively associated with their respective first lateral tendon ropes and second lateral tendon ropes. The first lateral tendon ropes and the second lateral tendon ropes are driven by the motor wheel corresponding to the same first motor or the second motor, and are wound in opposite directions on the same motor wheel. The joint movement of the first motor and the second motor forms a joint drive mode, and the relative movement of the first motor and the second motor forms a preload mode or a spring-limited retention mode.

4. The robotic finger tendon cable transmission system as described in claim 3, characterized in that, The spring and the limiting part that cooperates with the spring are connected in series in the tendon path corresponding to the first side tendon and the second side tendon. When the spring extends to the limiting position, the limiting part contacts the spring and bears the subsequent load, thereby increasing the equivalent stiffness of the corresponding tendon path.

5. The robotic finger tendon cable transmission system as described in claim 4, characterized in that, The equivalent center of the follower support, the first crossing point, and the second crossing point all rotate around the same fixed reference point on the proximal joint.

6. A control method for a robot finger tendon cable transmission system as described in any one of claims 3 to 5, characterized in that, Including the following steps: S1, read the proximal joint angle, distal joint angle, and motor angles of the two motors on the same drive unit; S2, calculate the length changes of the passage paths of the first side tendon rope and the second side tendon rope according to the geometric model of the passage structure; S3, calculate the differential mode length change and common mode length change caused by the through-wire structure; S4, calculate the joint driving mode based on the desired proximal / distal joint angle; S5, calculate the preload mode based on the target spring elongation or the limit retention target; S6, superimposes the differential mode compensation of the line-crossing structure onto the corresponding motor's drive mode; S7, the target angle or target speed of the two motors on the same drive unit is obtained by modal inversion transformation; S8 performs closed-loop control of the position, speed, or torque of the corresponding motor.

7. The control method as described in claim 6, characterized in that, In step S2, The length of the path of the first lateral tendon cord changes as follows: The length of the path of the second lateral tendon cord changes as follows: in, The first lateral tendon chord path at the proximal joint angle is The length of time; The second lateral tendon tract path at the proximal joint angle is The length of time; This serves as a reference joint angle for calculating length variations; The first lateral tendon chord path at the proximal joint angle is The length of time; The second lateral tendon tract path at the proximal joint angle is The length of time; The first lateral tendon ligament path is... To reference joint angle The length change; For the second lateral tendon tract path by To reference joint angle The length changes.

8. The control method as described in claim 7, characterized in that, In step S3, Differential mode length variation The calculation formula is: Common mode length variation The calculation formula is: 。 9. The control method as described in claim 8, characterized in that, ... The motor angle of the first motor The motor angle of the second motor ; In step S4, the driving mode of the joint The expression is: In step S5, the pre-tightening mode of the joint The expression is: In step S7, the inverse transformation expression is: 。 10. The control method as described in claim 9, characterized in that, In step S6, the differential mode compensation of the through-line structure is performed. The expression is: in, To compensate for differential mode gain; Let be the radius of the motor wheel.

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