Rope-driven joint module, mechanical arm and robot

Abstract

The invention discloses a rope-driven joint module, a mechanical arm and a robot, and belongs to the technical field of robots. The rope-driven joint module comprises a first joint part and a second joint part, the second joint part is rotatably connected to the first joint part through the driving module, the rotating wheel is connected with the output end of the driving motor, the two sides of the rotating wheel are each provided with a cam, the cams make contact with the driven parts, and the cams rotate to make the driven parts do reciprocating motion; one end of the driving rope is connected with the second joint part, the other end of the driving rope penetrates through a through hole in the end face of the first joint part and is wound around the driven piece to be connected with the cam, the curvature of the cam is positive, and the driving rope penetrates through the contact portion of the cam and the driven piece and is wound around the cam. And the rope-driven joint module can realize bidirectional driving of a rope-driven rotary joint driven by a single driving motor through a cam.

Description

Technical Field

[0001] This application belongs to the technical field of robotics, and particularly relates to a cable-driven joint module, a robotic arm, and a robot. Background Art

[0002] In recent years, cable-driven joint mechanisms have been widely used in the field of robotics due to their advantages such as light weight, high flexibility, and long power transmission time.

[0003] Since a rope can only provide tensile force and not support force, the number of driving ropes should be at least greater than the dimension of the joint degrees of freedom. For example, at least n + 1 driving ropes are required to fully drive a cable-driven joint with n degrees of freedom. For bidirectional rotation of a certain degree of freedom, at least two driving ropes are required. In most cases, the changes in the lengths of the two driving ropes during the rotation of the joint are not equal. Most existing cable-driven joints use two motors to drive the two driving ropes respectively. Summary of the Invention

[0004] This application aims to solve at least one of the technical problems existing in the prior art. For this purpose, this application provides a cable-driven joint module, a robotic arm, and a robot, which can achieve bidirectional driving of a cable-driven rotary joint through a single motor, has high control precision, does not require additional structures, and has high universality.

[0005] In a first aspect, this application provides a cable-driven joint module, including:

[0006] A first joint part and a second joint part;

[0007] A driving module, the second joint part is rotatably connected to the first joint part through the driving module. The driving module includes a driving motor, a transmission mechanism, and a pair of driving ropes. The pair of driving ropes includes two driving ropes. The transmission mechanism includes a rotating wheel and two driven parts. The rotating wheel is connected to the output end of the driving motor. A cam is provided on each side of the rotating wheel. The cam contacts the driven part, and the rotation of the cam causes the driven part to perform a reciprocating motion;

[0008] One end of the driving rope is connected to the second joint part, and the other end of the driving rope passes through a through hole on the end face of the first joint part and is connected to the cam. The curvature of the cam is positive. The driving rope passes through the part where the cam contacts the driven part, and the driving rope is wound around the cam;

[0009] Wherein, the driving motor is used to drive the rotating wheel to rotate, driving one of the driving ropes in the driving rope pair to be sucked in by one of the cams, and driving the other cam to release the other driving rope in the driving rope pair, so as to realize the rotational freedom of the second joint part along the direction of the line connecting the two connection points of the two driving ropes and the first joint part.

[0010] According to the rope-driven joint module of the present application, by setting a transmission mechanism with two independent cams to separately suck in and release the driving ropes on both sides, a single driving motor can achieve the bidirectional drive of the rope-driven rotary joint, with high control precision and no need to additionally set other structures, having high universality.

[0011] According to an embodiment of the present application, the end of the first joint part facing the second joint part is a plane, and the end of the second joint part facing the first joint part is a plane.

[0012] According to an embodiment of the present application, the transmission mechanism further includes two tension pre-tightening devices, which are located between the driven part and the end face of the first joint part, and the tension pre-tightening devices are in contact with the driving ropes.

[0013] According to an embodiment of the present application, it further includes:

[0014] Two tension sensors corresponding to the two driving ropes one by one, the tension sensors are located between the tension pre-tightening devices and the end face of the first joint part, the tension sensors are in contact with the driving ropes, and the tension sensors are used to detect the tension of the driving ropes.

[0015] According to an embodiment of the present application, the displacement range of the reciprocating movement of the driven part is determined based on the contour parameters of the cam.

[0016] According to an embodiment of the present application, the driving module further includes:

[0017] A limiting mechanism, which is arranged at the connection between the rotating wheel and the output end of the driving motor, and the limiting mechanism is used to limit the position of the rotating wheel so that the zero position of the cam is aligned with the zero position of the second joint part.

[0018] According to an embodiment of the present application, the distance between the center point of the rotation of the second joint part and the connection point of the driving rope and the first joint part is a first distance;

[0019] When the second joint part is in the zero position, the length of the driving rope exposed from the end of the second joint part is a second distance;

[0020] Among them, the ratio of the first distance to the second distance is 1 / 3 - 2 / 3.

[0021] According to an embodiment of the present application, it further includes:

[0022] A first encoder, which is disposed on one of the second joint part or the first joint part, and the first encoder is used to detect the joint rotation angle of the second joint part relative to the first joint part;

[0023] A second encoder, which is disposed on the drive motor, and the second encoder is used to detect the motor rotation angle of the rotating wheel.

[0024] In a second aspect, the present application provides a robotic arm, including:

[0025] At least one cable-driven joint module as described in the first aspect above.

[0026] In a third aspect, the present application provides a robot, characterized by including:

[0027] At least one robotic arm as described in the second aspect above.

[0028] The additional aspects and advantages of the present application will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present application. Description of the Drawings

[0029] The above and / or additional aspects and advantages of the present application will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0030] Figure 1 is one of the schematic structural diagrams of the cable-driven joint module provided by the embodiment of the present application;

[0031] Figure 2 is the second schematic structural diagram of the cable-driven joint module provided by the embodiment of the present application;

[0032] Figure 3 is the schematic diagram of the plane where the first drive cable of the cable-driven joint module provided by the embodiment of the present application is located;

[0033] Figure 4 is the schematic diagram of the plane where the second drive cable of the cable-driven joint module provided by the embodiment of the present application is located;

[0034] Figure 5 is the third schematic structural diagram of the cable-driven joint module provided by the embodiment of the present application;

[0035] Figure 6It is the fourth schematic structural diagram of the cable-driven joint module provided by the embodiment of the present application;

[0036] Figure 7 It is the fifth schematic structural diagram of the cable-driven joint module provided by the embodiment of the present application;

[0037] Figure 8 It is the sixth schematic structural diagram of the cable-driven joint module provided by the embodiment of the present application;

[0038] Figure 9 It is the schematic flow diagram of the cam profile design method of the cable-driven joint module provided by the embodiment of the present application;

[0039] Figure 10 It is the schematic cam profile diagram of the optimization target coefficient provided by the embodiment of the present application;

[0040] Figure 11 It is the schematic structural diagram of the cam profile design device of the cable-driven joint module provided by the embodiment of the present application;

[0041] Figure 12 It is the schematic structural diagram of the electronic device provided by the embodiment of the present application.

[0042] Reference numerals:

[0043] The first joint part 100, the first joint end part 110, the second joint part 200, the second joint end part 210, the drive cable 300, the first drive cable 310, the second drive cable 320, the central rod 410, the spherical hinge structure 411,

[0044] The drive motor 510, the rotating wheel 521, the cam 522, the follower 523, the contact point 524, the tension pre-tightening device 530. Detailed implementation manners

[0045] Next, the technical solutions in the embodiments of the present application will be clearly described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0046] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0047] In combination with the accompanying drawings, the rope-driven joint module, the robotic arm, the robot, the cam profile design method of the rope-driven joint module, the electronic device and the readable storage medium provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0048] The embodiment of the present application provides a rope-driven joint module, the rotation of the two degrees of freedom of the joint is decoupled, and the flexibility of the joint driving is high.

[0049] like Figure 1 As shown, the rope-driven joint module includes: a first joint part 100 , a second joint part 200 and a driving module, wherein the driving module includes a central rod 410 , two first driving ropes 310 and two second driving ropes 320 .

[0050] In this embodiment, both ends of the center rod 410 are respectively disposed at the end centers of the first joint portion 100 and the second joint portion 200 , and the center rod 410 is supported between the first joint portion 100 and the second joint portion 200 .

[0051] In some embodiments, the end of the first joint portion 100 facing the second joint portion 200 is a plane, and the end of the second joint portion 200 facing the first joint portion 100 is a plane.

[0052] It should be noted that the center rod 410 is supported between the first joint part 100 and the second joint part 200, leaving space for the second joint part 200 to rotate relative to the first joint part 100. The opposite end faces of the two joint parts do not need to be configured as arc surfaces for easy pivoting, and the smoothness of the rotation of the two joint parts can also be ensured. The rope-driven joint module has high universality.

[0053] like Figure 2As shown, the end of the first joint part 100 facing the second joint part 200 is the first joint end 110, and the end of the second joint part 200 facing the first joint part 100 is the second joint end 210. The first joint end 110 and the second joint end 210 can be set as planes. Among them, both ends of the central rod 410 are respectively set at the center of the ends of the first joint end 110 and the second joint end 210.

[0054] The two first driving ropes 310 of the driving module form a pair of first driving ropes. Both ends of each first driving rope 310 are respectively set at the ends of the first joint part 100 and the second joint part 200, and the two first driving ropes 310 are symmetrically distributed with respect to the central rod 410. The two first driving ropes 310 and the central rod 410 are in the same plane.

[0055] The two second driving ropes 320 of the driving module form a pair of second driving ropes. Both ends of each second driving rope 320 are respectively set at the ends of the first joint part 100 and the second joint part 200, and the two second driving ropes 320 are symmetrically distributed with respect to the central rod 410. The two second driving ropes 320 and the central rod 410 are in the same plane.

[0056] The connection line of the two connection points of the two first driving ropes 310 and the first joint part 100 forms a first rotation axis, and the connection line of the two connection points of the two second driving ropes 320 and the first joint part 100 forms a second rotation axis. The first rotation axis and the second rotation axis are vertically intersected at the center of the end of the first joint part 100. The plane where the two first driving ropes 310 are located and the plane where the two second driving ropes 320 are located are perpendicular and intersect at the central rod 410.

[0057] In this embodiment, the second joint part 200 is rotatably connected to the first joint part 100 through the driving module. Among them, the second joint part 200 is used to rotate along the first rotation axis to achieve the first degree of freedom rotation, and the second joint part 200 is used to rotate along the second rotation axis to achieve the second degree of freedom rotation.

[0058] In actual execution, the two first driving ropes 310 are symmetrically distributed with respect to the central rod 410. By taking in and releasing the two first driving ropes 310, the second joint part 200 can be driven to rotate along the second rotation axis to achieve the second degree of freedom rotation; the two second driving ropes 320 are symmetrically distributed with respect to the central rod 410. By taking in and releasing the two second driving ropes 320, the second joint part 200 can be driven to rotate along the first rotation axis to achieve the first degree of freedom rotation.

[0059] For example, as Figure 2As shown, the two first driving ropes 310 are ae and cg respectively. By retracting the ae rope downward and releasing the cg rope upward, the second joint part 200 is driven to rotate counterclockwise along the second rotation axis where the hf connection line is located.

[0060] By releasing the ae rope upward and retracting the cg rope downward, the second joint part 200 is driven to rotate clockwise along the second rotation axis where the hf connection line is located, realizing the bidirectional rotation of the rope-driven joint module in the second degree of freedom.

[0061] In this embodiment, the rotation of the second joint part 200 along the second rotation axis is only driven by the two first driving ropes 310 and has nothing to do with the two second driving ropes 320. Similarly, the rotation of the second joint part 200 along the first rotation axis is only driven by the two second driving ropes 320 and has nothing to do with the two first driving ropes 310. That is, the rotation of the rope-driven joint module in the two degrees of freedom is decoupled.

[0062] According to the rope-driven joint module provided by the embodiment of the present application, by setting two pairs of driving rope pairs, the two first driving ropes 310 are arranged on both sides of the central rod 410 to form the first rotation axis, and the two second driving ropes 320 are arranged on both sides of the central rod 410 to form the second rotation axis. The two rotation axes are perpendicular to each other and intersect at the central rod 410, realizing the rotation in two degrees of freedom. For each degree of freedom, the bidirectional rotation of the degree of freedom is controlled by two ropes, and the rotation in the two degrees of freedom is decoupled, and the flexibility of the joint drive of the rope-driven joint module is high.

[0063] In some embodiments, the drive module further includes a first drive device.

[0064] In this embodiment, the first ends of the two first driving ropes 310 are wound around the output end of the first drive device, the second ends of the two first driving ropes 310 are connected to the second joint part 200, and the first drive device is arranged on the first joint part 100.

[0065] The first ends of the first driving ropes 310 are connected to the output end of the first drive device. When the first drive device works, the first driving ropes 310 can be wound around the output end of the first drive device, and the first drive device retracts the first driving ropes 310. The first driving ropes 310 can also be unwound from the output end of the first drive device, and the first drive device releases the first driving ropes 310.

[0066] Taking the first drive device as a motor as an example.

[0067] The first end of the first drive rope 310 is connected to the output shaft of the motor, and the second end of the first drive rope 310 is connected to the second joint portion 200. When the output shaft of the motor rotates in one direction, the first drive rope 310 is retracted. When the output shaft of the motor rotates in the other direction, the first drive rope 310 is released.

[0068] For example, as Figure 2 shown, the two first drive ropes 310 are ae and cg respectively. The first drive device retracts the ae rope and releases the cg rope, driving the second joint portion 200 to rotate counterclockwise along the second rotation axis where the hf line is located. The first drive device releases the ae rope and retracts the cg rope, driving the second joint portion 200 to rotate clockwise along the second rotation axis where the hf line is located.

[0069] It should be noted that the first drive device may include two output ends in different directions. One of the first drive ropes 310 is retracted and the other first drive rope 310 is released to drive the two first drive ropes 310 to drive the second joint portion 200 to rotate. Among them, the two output ends in different directions may be the output ends of the two motors of the first drive device, or may be the two output ends output by one motor of the first drive device through a transmission mechanism.

[0070] In some embodiments, the first drive device is used to drive the second joint portion 200 to rotate along the second rotation axis through the two first drive ropes 310, and the length of the second drive rope 320 between the first joint portion 100 and the second joint portion 200 is equal to the length of the central rod 410.

[0071] In this embodiment, the rotation of the second joint portion 200 along the second rotation axis is only achieved by the first drive device driving the two first drive ropes 310. When realizing the second-degree-of-freedom rotation, the lengths of the two second drive ropes 320 between the first joint portion 100 and the second joint portion 200 are equal to the length of the central rod 410 and remain unchanged.

[0072] For example, as Figure 2 shown, the two first drive ropes 310 are ae and cg respectively, and the two second drive ropes 320 are bf and dh respectively.

[0073] As Figure 3 shown, the first drive device retracts the ae rope with a length of Δl1 downward and releases the cg rope with a length of Δl3 upward, driving the second joint portion 200 to rotate counterclockwise by an angle of θ along the second rotation axis where the hf line is located.

[0074] As Figure 4As shown, between the first joint part 100 and the second joint part 200, the length of the bf rope is Δl2, the length of the dh rope is Δl4, the lengths of the two second driving ropes 320 are equal to the length of the central rod 410, and remain unchanged during the rotation of the second joint part 200 along the second rotation axis.

[0075] In some embodiments, the driving module further includes: a second driving device.

[0076] In this embodiment, the first ends of the two second driving ropes 320 are wound around the output end of the second driving device, the second ends of the two second driving ropes 320 are connected to the second joint part 200, and the second driving device is arranged on the first joint part 100.

[0077] The first end of the second driving rope 320 is connected to the output end of the second driving device. When the second driving device works, the second driving rope 320 can be wound around the output end of the second driving device, the second driving device takes in the second driving rope 320, and the second driving rope 320 can also be unwound from the output end of the second driving device, and the second driving device releases the second driving rope 320.

[0078] Taking the second driving device as a motor as an example.

[0079] The first end of the second driving rope 320 is connected to the output shaft of the motor, the second end of the second driving rope 320 is connected to the second joint part 200, the output shaft of the motor rotates in one direction to take in the second driving rope 320, and the output shaft of the motor rotates in the other direction to release the second driving rope 320.

[0080] It should be noted that the second driving device may include two output ends in different directions. One of the second driving ropes 320 is taken in, and the other second driving rope 320 is released to drive the two second driving ropes 320 to drive the second joint part 200 to rotate. Among them, the two output ends in different directions may be the output ends of two motors of the second driving device, or two output ends output by one motor of the second driving device through a transmission mechanism.

[0081] In some embodiments, the second driving device is used to drive the second joint part 200 to rotate along the first rotation axis through the two second driving ropes 320, and the length of the first driving rope 310 between the first joint part 100 and the second joint part 200 is equal to the length of the central rod 410.

[0082] In this embodiment, the rotation of the second joint portion 200 along the first rotation axis is only driven by the second driving device to drive two second driving ropes 320. When realizing the rotation of the first degree of freedom, the lengths of the two first driving ropes 310 between the first joint portion 100 and the second joint portion 200 are equal to the length of the central rod 410 and remain unchanged.

[0083] In some embodiments, one end of the central rod 410 is hinged to the first joint portion 100, and the other end of the central rod 410 is fixedly connected to the second joint portion 200.

[0084] In this embodiment, one end of the central rod 410 is rotatably connected to the first joint portion 100, the other end of the central rod 410 is fixedly connected to the second joint portion 200, the central rod 410 is supported between the first joint portion 100 and the second joint portion 200, and the second joint portion 200 rotates relative to the first joint portion 100 through the hinge structure of the central rod 410.

[0085] It can be understood that the angle range of the rotation of the second joint portion 200 relative to the first joint portion 100 is determined based on the rotation range of the hinge of one end of the central rod 410 with the first joint portion 100.

[0086] In some embodiments, a spherical hinge structure 411 is provided at one end of the central rod 410, and one end of the central rod 410 is hinged to the first joint portion 100 through the spherical hinge structure 411.

[0087] As Figure 2 shown, a spherical hinge structure 411 is provided at one end of the central rod 410, the spherical hinge structure 411 is hinged to the end center of the first joint end portion 110, and the other end of the central rod 410 is fixedly connected to the end center of the second joint end portion 210.

[0088] It can be understood that the spherical hinge structure 411 can ensure that the rotation of the second joint portion 200 relative to the first joint portion 100 is smoother and has a larger rotation range.

[0089] The embodiment of the present application further provides a robotic arm, including at least one rope-driven joint module as described above.

[0090] Among them, the rope-driven joint module can realize the rotation of two degrees of freedom, and the rotation of the two degrees of freedom is decoupled. The robotic arm composed of the rope-driven joint module can effectively resist external disturbances, and the ropes used for driving have the characteristics of light weight, high flexibility and convenient long-power transmission.

[0091] According to the robotic arm provided by the embodiments of the present application, the cable-driven joint module realizes two degrees of freedom of rotation by arranging two pairs of driving cable pairs. Two first driving cables 310 are arranged on both sides of the central rod 410 to form a first rotation axis, and two second driving cables 320 are arranged on both sides of the central rod 410 to form a second rotation axis. The two rotation axes are perpendicular to each other and intersect at the central rod 410, realizing two degrees of freedom of rotation. For each degree of freedom, the bidirectional rotation of the degree of freedom is controlled by two cables, and the two degrees of freedom of rotation are decoupled, so the flexibility of the joint drive of the cable-driven joint module is high.

[0092] The embodiments of the present application also provide a robot, including at least one robotic arm as described above.

[0093] Among them, the cable-driven joint module of the robotic arm can realize two degrees of freedom of rotation, and the two degrees of freedom of rotation are decoupled. The robotic arm can be used in parts such as the neck, wrist, tail, and operating structure of the robot.

[0094] According to the robot provided by the embodiments of the present application, the cable-driven joint module realizes two degrees of freedom of rotation by arranging two pairs of driving cable pairs. Two first driving cables 310 are arranged on both sides of the central rod 410 to form a first rotation axis, and two second driving cables 320 are arranged on both sides of the central rod 410 to form a second rotation axis. The two rotation axes are perpendicular to each other and intersect at the central rod 410, realizing two degrees of freedom of rotation. For each degree of freedom, the bidirectional rotation of the degree of freedom is controlled by two cables, and the two degrees of freedom of rotation are decoupled, so the flexibility of the joint drive of the cable-driven joint module is high.

[0095] Currently, for the bidirectional rotation of one degree of freedom of the cable-driven joint, two motors are mostly used to drive two driving cables respectively.

[0096] In the related art, there are mainly two schemes for using one motor to drive two driving cables: the first is to design the actuators at the contact parts of the two joints as circular, so that the cable lengths of the two driving cables change equally, and then drive them with one motor, but such circular actuators do not have universality; the second is to install a passive recovery device such as a torsion spring. One direction of the driving cable is driven by a motor, and the other direction of the driving cable is recovered by the passive recovery device, and the driving control accuracy is low and bidirectional driving cannot be realized.

[0097] The embodiments of the present application also provide a cable-driven joint module, which can realize the bidirectional drive of the cable-driven rotary joint through a single motor, with high control accuracy, no need to set other structures additionally, and has high universality.

[0098] As Figure 5 shown, the cable-driven joint module includes a first joint part 100, a second joint part 200 and a driving module. The second joint part 200 is rotatably connected to the first joint part 100 through the driving module.

[0099] Among them, the driving module includes a driving motor 510, a transmission mechanism, and a driving rope pair. The driving rope pair includes two driving ropes 300. The transmission mechanism includes a rotating wheel 521 and two driven members 523. The rotating wheel 521 is connected to the output end of the driving motor 510. A cam 522 is provided on each side of the rotating wheel 521. The cam 522 contacts the driven member 523. When the cam 522 rotates, the driven member 523 makes a reciprocating motion.

[0100] It should be noted that the cam 522 is a member with a curved profile and makes a rotary motion; the driven member 523 contacts the profile of the cam 522. The driven member 523 is a member that transmits power to realize the winding and unwinding of the driving rope 300. The cam 522 rotates together with the rotating wheel 521, and the driven member 523 makes a reciprocating motion within a certain range.

[0101] The rotating wheel 521 is connected to the output end of the driving motor 510. A cam 522 is provided on each side of the rotating wheel 521. Driven by the output end of the driving motor 510, the two cams 522 on the rotating wheel 521 make a rotary motion, and then through the power transmission of the two driven members 523, the winding and unwinding of the driving rope 300 are realized.

[0102] In this embodiment, one end of the driving rope 300 is connected to the second joint part 200, and the other end of the driving rope 300 passes through the through hole on the end face of the first joint part 100 and is connected to the cam 522. The driving rope 300 passes through the part where the cam 522 and the driven member 523 contact, and the driving rope 300 is wound around the cam 522.

[0103] It can be understood that when the cam 522 rotates, the driving rope 300 is pressed by the driven member 523 and wound around or released from the cam 522. The upward and downward movements of the driven member 523 are restricted by the profile of the cam 522. The driven member 523 can ensure that the driving rope 300 can completely wind around the cam 522 and leave or enter the cam 522 from a specified position (the part where the cam 522 and the driven member 523 contact).

[0104] Among them, the driving motor 510 is used to drive the rotating wheel 521 to rotate, drive one cam 522 to draw in one driving rope 300 in the driving rope pair, and drive the other cam 522 to release the other driving rope 300 in the driving rope pair, so as to realize the rotational freedom of the second joint part 200 along the direction of the line connecting the two connection points of the two driving ropes 300 and the first joint part 100.

[0105] For example, for the end of the first joint part 100, the two connection points of the two driving ropes 300 and the first joint part 100 where the second joint part 200 is located are distributed on the left and right sides of the end.

[0106] The drive motor 510 drives the rotating wheel 521 to rotate, driving the left cam 522 to rotate, sucking in the left drive rope 300, and at the same time driving the right cam 522 to rotate, releasing the right drive rope 300, and the second joint part 200 rotates from right to left.

[0107] It can be understood that the contour of the cam 522 is different from the circular contour. By setting two independent cams 522 in the transmission mechanism, the length changes of the two drive ropes 300 during the joint rotation can be made unequal. Using one drive motor 510 can drive the two drive ropes 300 to achieve bidirectional rotation of a certain degree of freedom.

[0108] It should be noted that the curvature of the cam 522 of the transmission mechanism is positive, which can ensure that during the rotation process, the stress magnitude of the drive rope 300 remains unchanged, ensuring the effectiveness of the joint movement.

[0109] In some embodiments, as Figure 6 shown, the cable-driven joint module includes a first drive rope pair composed of two first drive ropes 310, a second drive rope pair composed of two second drive ropes 320, and a central rod 410.

[0110] The connection line of the two connection points of the two first drive ropes 310 with the first joint part 100 forms a first rotation axis, and the connection line of the two connection points of the two second drive ropes 320 with the first joint part 100 forms a second rotation axis. The first rotation axis and the second rotation axis are perpendicularly intersected at the end center of the first joint part 100. The second joint part 200 can rotate along the first rotation axis to achieve the first degree of freedom rotation, and rotate along the second rotation axis to achieve the second degree of freedom rotation.

[0111] In this embodiment, a set of drive motor 510 and transmission mechanism can be configured for the first drive rope pair to achieve the second degree of freedom rotation, and a set of drive motor 510 and transmission mechanism can be configured for the second drive rope pair to achieve the first degree of freedom rotation.

[0112] According to the cable-driven joint module provided by the embodiments of the present application, by setting a transmission mechanism with two independent cams 522 to respectively suck in and release the drive ropes 300 on both sides, a single drive motor 510 can achieve the bidirectional drive of the cable-driven rotary joint, with high control precision, no need to additionally set other structures, and has high universality.

[0113] In some embodiments, the end of the first joint part 100 facing the second joint part 200 is a plane, and the end of the second joint part 200 facing the first joint part 100 is a plane.

[0114] It can be understood that two independent cams 522 on the transmission mechanism can make the length changes of the two drive ropes 300 unequal during the rotation of the joint, and the opposite end faces of the two joint parts do not need to be set as arc surfaces facilitating pivoting, that is, the opposite end faces of the two joint parts do not need to be designed as circular actuators.

[0115] In this embodiment, the end of the first joint part 100 facing the second joint part 200 is set as a flat surface, and the end of the second joint part 200 facing the first joint part 100 is set as a flat surface, which can improve the universality of the cable-driven joint module.

[0116] In some embodiments, the transmission mechanism further includes two tension pre-tightening devices 530 corresponding to the two drive ropes 300 one by one. The tension pre-tightening device 530 is located between the driven member 523 and the end face of the first joint part 100, and the tension pre-tightening device 530 is in contact with the drive rope 300.

[0117] In this embodiment, the tension pre-tightening device 530 and the transmission mechanism can be arranged in the internal space of the first joint part 100. One end of the drive rope 300 is connected to the second joint part 200, and the other end of the drive rope 300 passes through the through hole on the end face of the first joint part 100, enters the internal space of the first joint part 100, first contacts the tension pre-tightening device 530, then winds around the driven member 523, and finally is connected to the cam 522.

[0118] It should be noted that one end of the drive rope 300 is fixedly connected to the second joint part 200, and the other end of the drive rope 300 is fixedly connected to the cam 522. During the rotation of the cam 522, the drive rope 300 can wind or unwind on the cam 522.

[0119] In this embodiment, a tension pre-tightening device 530 is arranged between the driven member 523 and the end face of the first joint part 100. By applying a force to the drive rope 300 through the tension pre-tightening device 530, the drive rope 300 is kept under a certain stress to ensure the effectiveness of the joint movement.

[0120] In some embodiments, the cable-driven joint module may further include two tension sensors corresponding to the two drive ropes 300 one by one. The tension sensor is located between the tension pre-tightening device 530 and the end face of the first joint part 100, the tension sensor is in contact with the drive rope 300, and the tension sensor is used to detect the tension of the drive rope 300.

[0121] In this embodiment, each drive rope 300 is configured with a corresponding tension sensor. The tension sensor is arranged in the space between the tension pre-tightening device 530 and the end face of the first joint part 100. According to the tension of the drive rope 300 detected by the tension sensor, the magnitude of the force applied by the tension pre-tightening device 530 to the drive rope 300 can be adjusted.

[0122] In some embodiments, the displacement range of the reciprocating motion of the follower 523 is determined based on the profile parameters of the cam 522.

[0123] In this embodiment, the driving rope 300 is connected to the second joint portion 200. The other end of the driving rope 300 first passes through the through hole at the end face of the first joint portion 100, and then passes through the contact portion between the cam 522 and the follower 523 and is connected to the cam 522. When the cam 522 rotates, the driving rope 300 is pressed by the follower 523 to wind around or unwind from the cam 522, and the upward and downward movements of the follower 523 are restricted by the profile of the cam 522.

[0124] In actual implementation, the rotation trajectory of the cam 522 can be calculated according to the profile parameters of the cam 522. According to the rotation trajectory of the cam 522, the upward and downward movement distances of the follower 523 can be calculated to obtain the displacement range of the reciprocating motion of the follower 523.

[0125] In some embodiments, the driving module may further include a limiting mechanism.

[0126] In this embodiment, the limiting mechanism is arranged at the connection between the rotating wheel 521 and the output end of the driving motor 510. The limiting mechanism is used to limit the position of the rotating wheel 521 so that the zero position of the cam 522 is aligned with the zero position of the second joint portion 200.

[0127] It should be noted that the profile of the cam 522 is different from the circular profile. Starting from different positions, the profile changes of the cam 522 when rotating the same angle are different, that is, the lengths of the driving rope 300 absorbed or released by the cam 522 and the follower 523 are different.

[0128] In this embodiment, the position of the rotating wheel 521 is restricted by the limiting mechanism so that the zero position of the cam 522 is aligned with the zero position of the second joint portion 200, and the corresponding relationship between the rotation angle of the rotating wheel 521 and the length change of the driving rope 300 on the cam 522 is determined, thereby realizing precise control of the rotation angle of the second joint portion 200.

[0129] In actual implementation, the limiting mechanism may include a limiting pin and a limiting hole provided on the rotating wheel 521. When adjusting the zero positions of the cam 522 and the second joint portion 200, the limiting pin is inserted into the limiting hole.

[0130] Among them, the zero position of the second joint portion 200 may be the position where the rotation angle of the second joint portion 200 is 0, and the zero position of the cam 522 may be the position of the connection point between the cam 522 and the driving rope 300.

[0131] In some embodiments, the distance between the center point of rotation of the second joint portion 200 and the connection point of the drive cable 300 and the first joint portion 100 is the first distance;

[0132] When the second joint portion 200 is in the zero position, the length of the drive cable 300 exposed from the end portion 210 of the second joint portion is the second distance;

[0133] Wherein, the ratio of the first distance to the second distance is 1 / 3 - 2 / 3.

[0134] It should be noted that the second joint portion 200 rotates along the direction of the line connecting the two connection points of the two drive cables 300 and the first joint portion 100. The center point of rotation of the second joint portion 200 is the midpoint of the two connection points of the two drive cables 300 and the first joint portion 100, that is, the first distance is half of the distance of the line connecting the two connection points.

[0135] The zero position of the second joint portion 200 can be the position where the rotation angle of the second joint portion 200 is 0. When the second joint portion 200 is in the zero position, the length of the drive cable 300 exposed from the end portion 210 of the second joint portion can be equal to the distance from the connection point of the drive cable 300 and the first joint portion 100 to the connection point of the drive cable 300 and the second joint portion 200.

[0136] In some embodiments, as Figure 6 shown, the cable-driven joint module includes a central rod 410. When the second joint portion 200 is in the zero position, the length of the drive cable 300 exposed from the end portion 210 of the second joint portion can be equal to the length of the central rod 410.

[0137] It should be noted that by setting the ratio of the first distance to the second distance to 1 / 3 - 2 / 3 and adjusting the sizes of the first joint portion 100, the second joint portion 200, and the drive cable 300, the control accuracy of the rotation of the second joint portion 200 relative to the first joint portion 100 can be ensured.

[0138] For example, as Figure 7 shown, the first distance w = 18 mm, the second distance is h = 40 mm, and the ratio of the first distance to the second distance is approximately 1 / 2, ensuring the control accuracy of the rotation of the second joint portion 200 relative to the first joint portion 100.

[0139] In some embodiments, the cable-driven joint module further includes a first encoder and a second encoder.

[0140] Among them, the first encoder is disposed in one of the second joint portion 200 or the first joint portion 100, and the first encoder is used to detect the joint rotation angle of the second joint portion 200 relative to the first joint portion 100; the second encoder is disposed in the drive motor 510, and the second encoder is used to detect the motor rotation angle of the rotating wheel 521. An embodiment of the present application also provides a robot including at least one cable-driven joint module as described above.

[0141] Among them, the cable-driven joint module can realize bidirectional rotation of the joint by a single drive motor 510 through a transmission mechanism provided with two independent cams 522.

[0142] In actual implementation, the cable-driven joint module can be used to construct the robotic arm of the neck, wrist, tail, operating structure, etc. of the robot, so that the robotic arm can effectively resist external disturbances, and the driving ropes used have the characteristics of light weight, high flexibility and convenient long-power transmission.

[0143] According to the robot provided by the embodiment of the present application, the cable-driven joint module respectively inhales and releases the driving ropes 300 on both sides through a transmission mechanism provided with two independent cams 522, and a single drive motor 510 can realize bidirectional drive of the cable-driven rotary joint, with high control accuracy, no need to additionally set other structures, and has high universality.

[0144] According to the robot provided by the embodiment of the present application, the cable-driven joint module respectively inhales and releases the driving ropes 300 on both sides through a transmission mechanism provided with two independent cams 522, and a single drive motor 510 can realize bidirectional drive of the cable-driven rotary joint, with high control accuracy, no need to additionally set other structures, and has high universality.

[0145] An embodiment of the present application also provides a cam profile design method for a cable-driven joint module, and the designed cam 522 can realize bidirectional drive of the cable-driven rotary joint through a single motor.

[0146] As Figure 5 shown, the cable-driven joint module includes a first joint portion 100, a second joint portion 200 and a drive module, and the second joint portion 200 is rotatably connected to the first joint portion 100 through the drive module.

[0147] The drive module includes a drive motor 510, a rotating wheel 521 and a pair of drive ropes. The pair of drive ropes includes two drive ropes 300. The rotating wheel 521 is connected to the output end of the drive motor 510, and a cam 522 is provided on each side of the rotating wheel 521.

[0148] One end of the drive rope 300 is connected to the second joint portion 200, and the other end of the drive rope 300 passes through the through hole on the end face of the first joint portion 100 and is connected to the cam 522.

[0149] The driving motor 510 is used to drive the rotating wheel 521 to rotate, drive one of the driving ropes 300 in the driving rope pair by driving a cam 522 to suck in, and drive the other cam 522 to release the other driving rope 300 in the driving rope pair, so as to realize the rotational degree of freedom of the second joint part 200 along the direction of the line connecting the two connection points of the two driving ropes 300 and the first joint part 100. Among them, the cam profile design method of the cable-driven joint module can be applied to the terminal, and can be specifically executed by the hardware or software in the terminal.

[0150] The cam profile design method of the cable-driven joint module provided by the embodiment of the present application, the execution subject of the cam profile design method of the cable-driven joint module can be an electronic device or a functional module or functional entity in the electronic device that can implement the cam profile design method of the cable-driven joint module. The electronic devices mentioned in the embodiments of the present application include but are not limited to mobile phones, tablet computers, computers, etc. Hereinafter, the cam profile design method of the cable-driven joint module provided by the embodiments of the present application will be described by taking the electronic device as the execution subject.

[0151] As Figure 9 shown, the cam profile design method of the cable-driven joint module includes: step 910 to step 970.

[0152] Step 910, obtain the length-angle correspondence relationship between the length of the driving rope 300 between the end faces of the first joint part 100 and the second joint part 200 and the joint rotation angle of the second joint part 200 rotating relative to the first joint part 100.

[0153] It can be understood that the length of the driving rope 300 between the end faces of the first joint part 100 and the second joint part 200 changes as the second joint part 200 is in different rotation positions (corresponding to different joint rotation angles). According to the angle range of the second joint part 200 rotating relative to the first joint part 100, the length-angle correspondence relationship can be obtained through geometric conversion.

[0154] For example, as Figure 7 shown, between the end faces of the first joint part 100 and the second joint part 200, the length of the left driving rope 300 is l L , and the length of the right driving rope 300 is l R .

[0155] When the second joint part 200 rotates leftward by θ from the vertical position, the relationship formula between l L and θ can be obtained through geometric conversion as follows:

[0156]

[0157] Wherein, h is the distance between the first joint part 100 and the second joint part 200, and this distance can be equal to the length of the central rod 410; w is the radius of the first joint part 100, and this radius can be equal to the distance between the center point of rotation of the second joint part 200 and the connection point between the driving rope 300 and the first joint part 100; a is the radius of the second joint part 200, and the value of a can be equal to w; θ is the joint rotation angle of the second joint part 200 rotating, and α is the deflection angle from the center of the end of the first joint part 100 to the connection point of the driving rope 300 on the second joint part 200.

[0158] Step 920: Based on the length-angle correspondence relationship, according to the characteristic that the length of the rope released and absorbed by the cam 522 corresponding to a certain motor rotation angle of the rotating wheel 521 is equal to the length of the rope released and absorbed by the end face of the first joint part 100 corresponding to a certain joint rotation angle of the second joint part 200, establish a first relationship model regarding the length of the driving rope 300, the contour length and the contour radius of the cam 522.

[0159] It should be noted that to ensure that no failure occurs during the joint rotation, the length of the rope released by one cam 522 of the transmission mechanism and the length of the rope absorbed by the other cam 522 should be respectively equal to the length of the rope released and absorbed by the end face of the first joint part 100 when the second joint part 200 rotates.

[0160] For example, as Figure 7 shown, when the rotating wheel 521 rotates counterclockwise by a small angle dq, the cam 522 corresponding to the driving rope on the left absorbs a driving rope 300 with a length of dl L The driving rope 300 with a length of dl is absorbed downward by the driving rope 300 on the left side of the end face of the first joint part 100 L The driving rope 300 with a length of dl; the cam 522 corresponding to the driving rope on the right absorbs a driving rope 300 with a length of dl R The driving rope 300 with a length of dl is absorbed downward by the driving rope 300 on the right side of the end face of the first joint part 100 R The driving rope 300 with a length of dl. It can be understood that the contour of the cam 522 on one side can be solved separately according to the length-angle correspondence relationship corresponding to this side.

[0161] In this embodiment, according to the length-angle correspondence relationship, establish a first relationship model for the length of the driving rope 300 on one side, the contour length and the contour radius of the cam 522, wherein the length of the driving rope 300 inhaled or released by the rotation of the cam 522 can be calculated according to the change of the contour length and the contour radius of the rotation of the cam 522.

[0162] In actual execution, as Figure 5As shown, the driving module further includes two driven members 523. One cam 522 is provided on each side of the rotating wheel 521. The cam 522 contacts the driven member 523. The driven member 523 is a component that transmits power to realize the winding and unwinding of the driving rope 300. When the cam 522 rotates, the driven member 523 makes a reciprocating motion.

[0163] When the cam 522 rotates, the driving rope 300 is pressed by the driven member 523 and wound around or released from the cam 522. The upward and downward movements of the driven member 523 are restricted by the contour of the cam 522. The driven member 523 can ensure that the driving rope 300 can completely wind around the cam 522 and leave or enter the cam 522 from a specified position (the contact part between the cam 522 and the driven member 523).

[0164] In some embodiments, as Figure 8 shown, the change in the contour radius of the cam 522 can be characterized by the small displacement change of the contact point 524 where the driven member 523 contacts the cam 522 during the rotation of the cam 522. That is, using a differential equation to describe the first relationship model of the length of the driving rope 300, the contour length of the cam 522, and the contour radius, the following first differential equation corresponding to the first relationship model can be obtained:

[0165] dl L (θ)+ds(q)+(-dr(q))=0

[0166] Where, dl L is the differential of the length of the driving rope 300, θ is the joint rotation angle of the second joint part 200, ds is the differential of the contour length of the cam 522, dr is the differential of the contour radius of the cam 522, and q is the motor rotation angle of the rotating wheel 521 (i.e., the rotation angle of the cam 522).

[0167] In some embodiments, the contour length of the cam 522 is calculated based on the contour radius of the cam 522 and the motor rotation angle of the rotating wheel 521 through the Pythagorean theorem.

[0168] In this embodiment, according to the constant stress of the driving rope 300, the change in the contour length of the cam 522 is equal to the change in the length of the driving rope 300 on the cam 522. According to the Pythagorean theorem, the following calculation formula for the differential of the contour length of the cam 522 can be obtained:

[0169]

[0170] Where, ds is the differential of the contour length of the cam 522, dr is the differential of the contour radius of the cam 522, and q is the motor rotation angle.

[0171] Step 930: Establish a second relationship model based on the linear correlation between the motor rotation angle of the rotating wheel 521 and the joint rotation angle of the second joint portion 200.

[0172] In this embodiment, based on the linear correlation between the motor rotation angle of the rotating wheel 521 and the joint rotation angle of the second joint portion 200, a second relationship model between the motor rotation angle and the joint rotation angle is established.

[0173] In some embodiments, a differential equation can be used to describe the second relationship model between the motor rotation angle and the joint rotation angle. For example, the second differential equation corresponding to the second relationship model is dq = Kr dθ, where dq is the differential value of the motor rotation angle, dθ is the differential value of the joint rotation angle, and Kr is the kinematic coefficient linearly related to the motor rotation angle and the joint rotation angle.

[0174] It can be understood that when the motor rotation angle and the joint rotation angle are linearly correlated, the control accuracy of joint rotation can be improved.

[0175] Step 940: Based on the first relationship model and the second relationship model, establish a target relationship model regarding the length of the drive cable 300, the motor rotation angle of the rotating wheel 521, and the profile radius of the cam 522.

[0176] In this step, according to the first relationship model representing the change relationship between the length of the drive cable 300, the profile length of the cam 522, and the profile radius, and the second relationship model representing the linear relationship between the motor rotation angle and the joint rotation angle, by substituting and eliminating variables such as the joint rotation angle and the profile length, a target relationship model regarding the length of the drive cable 300, the motor rotation angle of the rotating wheel 521, and the profile radius of the cam 522 is obtained.

[0177] For example, for the left drive cable 300, the first differential equation corresponding to the first relationship model is dl L (θ) + ds(q) + (-dr(q)) = 0, where The second differential equation corresponding to the second relationship model is dq = Kr dθ.

[0178] The target differential equation corresponding to the target relationship model calculated according to the first relationship model and the second relationship model is as follows:

[0179]

[0180] where r is the profile radius of the cam 522, q is the motor rotation angle, Kr is the kinematic coefficient linearly related to the motor rotation angle and the joint rotation angle, and dl L is the differential of the length of the drive cable 300.

[0181] Step 950: Determine the first constraint condition regarding the motor rotation angle of the rotating wheel 521 and the profile radius of the cam 522 according to the positive curvature characteristic of the cam 522.

[0182] In this embodiment, according to the positive curvature of the cam 522, the first constraint condition for the motor rotation angle and the profile radius of the cam 522 is established. The positive curvature of the cam 522 of the transmission mechanism can ensure that the above kinematic equation is satisfied during the rotation process. That is, the positive curvature of the cam 522 is the prerequisite for ensuring the effectiveness of joint movement.

[0183] During the process of solving the profile radius in the target relationship model, by constraining with the first constraint condition, it can effectively prevent the design of the cam 522 from having concave segments and avoid changing the stress magnitude of the driving cable 300.

[0184] According to the positive curvature of the cam 522, the determined first constraint condition can be as follows:

[0185]

[0186] Among them, r is the profile radius of the cam 522, and q is the motor rotation angle.

[0187] Step 960: Approximate the target relationship model according to the fact that the change of the profile radius of the cam 522 with respect to the motor rotation angle of the rotating wheel 521 is less than or equal to the square of the target coefficient and much less than 1.

[0188] It should be noted that when the motor rotation angle is small, the change of the profile radius of the cam 522 is also small, and the change of the profile radius of the cam 522 is even smaller with respect to the change of the motor rotation angle.

[0189] The change of the profile radius of the cam 522 with respect to the change of the motor rotation angle can be expressed as The magnitude of can be characterized by the target coefficient. The square of is less than or equal to the square of the target coefficient, and the square of the target coefficient is much less than 1, as shown in the following formula:

[0190]

[0191] Among them, ε is the target coefficient.

[0192] According to the inequality of the target coefficient, the target relationship model can be approximated to obtain the target differential equation corresponding to the following target relationship model:

[0193] Step 970: Solve the approximately processed target relationship model according to the boundary conditions and the first constraint condition of the contour radius of the cam 522 and the motor rotation angle of the rotating wheel 521, and obtain the solution set of the contour radius of the cam 522.

[0194] In this embodiment, for the approximately processed target relationship model, there is an analytical solution of the contour radius regarding the boundary conditions. Within the angular range of the motor rotation angle, the analytical solutions of multiple sampling points can be solved to obtain the solution set of the contour radius of the cam 522, which represents the contour of the cam 522.

[0195] In actual execution, for the contour of the cam 522, the analytical solution is continuous and smooth. The continuous solution can be discretized to facilitate the solution calculation of the contour radius.

[0196] For example, the boundary condition of the contour radius of the cam 522 and the motor rotation angle of the rotating wheel 521 is r(q0) = r0.

[0197] Let the function The target differential equation corresponding to the approximately processed target relationship model is The analytical solution corresponding to the boundary condition r(q0) = r0 is: where g(τ) = -f(τ)e -τ .

[0198] where τ represents the integration variable,

[0199] In this embodiment, it is defined that the angular range of the motor rotation angle is q ∈ [0, q M . N + 1 sampling points are collected within the domain to represent the contour of the cam 522.

[0200] It should be noted that the boundary conditions can be adjusted according to the cam 522 to be designed. After setting the boundary conditions, on the premise that the change in the contour radius of the cam 522 relative to the motor rotation angle of the rotating wheel 521 is less than or equal to the square of the target coefficient and much less than 1 and the first constraint condition, different target functions (for example, the cam 522 has the smallest contour size) are set, and the target relationship model is solved to obtain the solution set of the contour radius of the cam 522.

[0201] According to the cam profile design method of the cable-driven joint module provided by the embodiments of the present application, by means of system parameters such as the profile radius and profile length of the cam 522 and the kinematic relationship between the cam 522 driving the driving cable 300 to inhale and exhale, a target relationship model regarding the profile radius is established, and the track profile is jointly solved under the constraint that the curvature is positive. The designed cam 522 can achieve the bidirectional rotation of the rotating joint driven by a single rotating wheel 521, ensuring the control accuracy and motion stability of the cable-driven joint module.

[0202] In some embodiments, according to the boundary conditions and the first constraint condition of the profile radius of the cam 522 and the motor rotation angle of the rotating wheel 521, solving the approximately processed target relationship model may include:

[0203] According to the change of the profile radius of the cam 522 relative to the motor rotation angle of the rotating wheel 521 being less than or equal to the square of the target coefficient and much less than 1, the first constraint condition is approximately processed;

[0204] When the first constraint condition after the approximation process is satisfied and the change of the profile radius of the cam 522 relative to the motor rotation angle of the rotating wheel 521 is less than or equal to the square of the target coefficient and much less than 1, the boundary conditions are determined, and the approximately processed target relationship model is solved.

[0205] In this embodiment, according to the condition that the change of the profile radius of the cam 522 is relatively small relative to the change of the motor rotation angle, the first constraint condition regarding the profile radius of the cam 522 and the motor rotation angle is approximately processed.

[0206] For example, according to the positive curvature of the cam 522, the first constraint condition is According to The first constraint condition is approximately processed to obtain The inequality of.

[0207] According to the boundary conditions set for the cam 522 to be designed, when the first constraint condition after the approximation process is satisfied and the change of the profile radius of the cam 522 relative to the motor rotation angle of the rotating wheel 521 is less than or equal to the square of the target coefficient and much less than 1, the approximately processed target relationship model is solved to obtain the solution set of the profile radius of the cam 522.

[0208] In some embodiments, determining the boundary conditions may include:

[0209] Optimizing the target coefficient to determine the optimal target coefficient, and the approximation error between the target relationship model and the first constraint condition corresponding to the optimal target coefficient is the smallest;

[0210] Based on the optimal target coefficient, the boundary conditions are determined.

[0211] It can be understood that the approximate processing of the target relationship model and the first constraint condition is carried out under the condition that the change in the contour radius of the cam 522 is relatively small with respect to the change in the motor rotation angle, and the error generated by the approximate processing can be limited by the target coefficient.

[0212] For the first constraint condition after approximate processing At the sampling point k, there is According to the fact that the change in the contour radius of the cam 522 is relatively small with respect to the change in the motor rotation angle, it can be obtained that That is, the boundary condition r0 and the target coefficient ε are linearly related.

[0213] In this embodiment, the error generated by the approximate processing can be characterized as de(q) and can be limited by the target coefficient.

[0214] In actual execution, the target coefficient can be optimized to limit the error brought by the approximate processing, find the optimal target coefficient and the corresponding boundary condition through optimization, and then solve the target relationship model after approximate processing to obtain the solution of the contour radius of the cam 522.

[0215] In some embodiments, optimizing the target coefficient to determine the optimal target coefficient may include:

[0216] Search for the optimal target coefficient by the bisection method.

[0217] In this embodiment, search for the feasible and minimum optimal target coefficient that satisfies the condition that the change in the contour radius of the cam 522 is relatively small with respect to the change in the motor rotation angle by the bisection method.

[0218] A specific embodiment is introduced below.

[0219] As Figure 7 shown, for the cable-driven joint module, h = 40 mm, a = w = 18 mm.

[0220] As Figure 10 shown, four target coefficients ε of 0.6, 0.3, 0.15, and 0.21 are selected by the bisection method. Each curve represents the contour of the cam 522 with different target coefficients ε and different boundary conditions r0. When the curve representing the contour of the cam 522 is within the infeasible shaded area, it means that the boundary condition r0 and the target coefficient ε are infeasible.

[0221] For example, when the target coefficient ε = 0.3 and the boundary condition r0 = 5.7 mm, and the curve representing the contour of the cam 522 is within the shaded area, this boundary condition r0 and the target coefficient ε are infeasible.

[0222] In this embodiment, the bisection search yields the optimal target coefficient ε = 0.21, corresponding to r0 = 5.8 mm. The bold curve in (d) represents the contour of the cam 522. Substituting the optimal target coefficient ε = 0.21 and the boundary condition r0 = 5.8 mm into the analytical solution of the target relationship model, the contour radius solution of the cam 522 is obtained.

[0223] The embodiment of the present application also provides a cable-driven joint module.

[0224] As Figure 5 shown, the cable-driven joint module includes: a first joint portion 100, a second joint portion 200, and a driving module.

[0225] The driving module includes a driving motor 510, a rotating wheel 521, and a pair of driving cables. The pair of driving cables includes two driving cables 300. The rotating wheel 521 is connected to the output end of the driving motor 510. A cam 522 is provided on each side of the rotating wheel 521. One end of the driving cable 300 is connected to the second joint portion 200, and the other end of the driving cable 300 passes through the through hole on the end face of the first joint portion 100 and is connected to the cam 522. The driving motor 510 is used to drive the rotating wheel 521 to rotate, driving one cam 522 to draw in one driving cable 300 in the pair of driving cables, and driving the other cam 522 to release the other driving cable 300 in the pair of driving cables, so that the second joint portion 200 rotates in the degree of freedom direction along the line connecting the two connection points of the two driving cables 300 and the first joint portion 100.

[0226] In this embodiment, the contour of the cam 522 is determined based on the above-mentioned cam contour design method of the cable-driven joint module.

[0227] In actual execution, as Figure 5 shown, the driving module may further include two follower members 523. A cam 522 is provided on each side of the rotating wheel 521. The cam 522 is in contact with the follower member 523. The follower member 523 is a component that transmits power to realize the winding and unwinding of the driving cable 300. When the cam 522 rotates, the follower member 523 makes a reciprocating motion.

[0228] When the cam 522 rotates, the driving cable 300 is pressed by the follower member 523 to wind around or unwind from the cam 522. The upward and downward movements of the follower member 523 are restricted by the contour of the cam 522. The follower member 523 can ensure that the driving cable 300 can completely wind around the cam 522 and leave or enter the cam 522 from a specified position (the contact part of the cam 522 and the follower member 523).

[0229] According to the rope-driven joint module provided by the embodiments of the present application, by means of system parameters such as the contour radius and contour length of the cam 522 and the kinematic relationship between the cam 522 driving the driving rope 300 to inhale and exhale, a target relationship model regarding the contour radius is established, and the track contour is jointly solved under the constraint of positive curvature, and the designed cam 522. The rope-driven joint module composed of the cam 522 can realize the bidirectional rotation of a single rotating wheel 521 driving a rotating joint, ensuring the control accuracy and motion stability of the rope-driven joint module.

[0230] The embodiments of the present application further provide a robot, including: at least one rope-driven joint module as described above, and the contour of the cam 522 of the rope-driven joint module is determined based on the cam contour design method of the rope-driven joint module as described above.

[0231] For the cam contour design method of the rope-driven joint module provided by the embodiments of the present application, the execution subject can be a cam contour design device of the rope-driven joint module.

[0232] The embodiments of the present application further provide a cam contour design device for a rope-driven joint module.

[0233] As Figure 11 shown, the cam contour design device for the rope-driven joint module includes:

[0234] An acquisition module 1110, configured to acquire the length-angle correspondence relationship between the length of the driving rope 300 between the end faces of the first joint part 100 and the second joint part 200 and the joint rotation angle of the second joint part 200 rotating relative to the first joint part 100;

[0235] A first processing module 1120, configured to establish a first relationship model regarding the length of the driving rope 300, the contour length and contour radius of the cam 522 based on the length-angle correspondence relationship and according to the characteristic that the length of the rope released and absorbed by the cam 522 corresponding to the rotation angle of the rotating wheel 521 driving motor is equal to the length of the rope released and absorbed by the end face of the first joint part 100 corresponding to the joint rotation angle of the second joint part 200;

[0236] A second processing module 1130, configured to establish a second relationship model according to the linear correlation characteristic between the motor rotation angle of the rotating wheel 521 and the joint rotation angle of the second joint part 200;

[0237] A third processing module 1140, configured to establish a target relationship model regarding the length of the driving rope 300, the motor rotation angle of the rotating wheel 521 and the contour radius of the cam 522 based on the first relationship model and the second relationship model;

[0238] The fourth processing module 1150 is configured to determine a first constraint condition regarding the motor rotation angle of the rotating wheel 521 and the profile radius of the cam 522 according to the characteristic that the curvature of the cam 522 is positive;

[0239] The fifth processing module 1160 is configured to perform an approximation process on the target relationship model according to the change in the profile radius of the cam 522 relative to the motor rotation angle of the rotating wheel 521 being less than or equal to the square of the target coefficient and much less than 1;

[0240] The sixth processing module 1170 is configured to solve the approximated target relationship model according to the boundary conditions and the first constraint condition of the profile radius of the cam 522 and the motor rotation angle of the rotating wheel 521, and obtain a solution set of the profile radius of the cam 522.

[0241] According to the cam profile design device of the cable-driven joint module provided by the embodiments of the present application, a target relationship model regarding the profile radius is established through system parameters such as the profile radius and profile length of the cam 522 and the kinematic relationship between the cam 522 driving the driving cable 300 to inhale and exhale. Under the constraint of positive curvature, the track profile is jointly solved, and the designed cam 522 can achieve bidirectional rotation of a single rotating wheel 521 to drive a rotating joint, ensuring the control accuracy and motion stability of the cable-driven joint module.

[0242] In some embodiments, the sixth processing module 1170 is configured to perform an approximation process on the first constraint condition according to the change in the profile radius of the cam 522 relative to the motor rotation angle of the rotating wheel 521 being less than or equal to the square of the target coefficient and much less than 1;

[0243] Under the condition of satisfying the approximated first constraint condition and the change in the profile radius of the cam 522 relative to the motor rotation angle of the rotating wheel 521 being less than or equal to the square of the target coefficient and much less than 1, determine the boundary conditions and solve the approximated target relationship model.

[0244] In some embodiments, the sixth processing module 1170 is configured to optimize the target coefficient to determine an optimal target coefficient, and the approximation error between the target relationship model corresponding to the optimal target coefficient and the first constraint condition is the smallest;

[0245] Based on the optimal target coefficient, determine the boundary conditions.

[0246] In some embodiments, the sixth processing module 1170 is configured to search for the optimal target coefficient by the bisection method.

[0247] In some embodiments, the profile length of the cam 522 is calculated by the Pythagorean theorem based on the profile radius of the cam 522 and the motor rotation angle of the rotating wheel 521.

[0248] The cam profile design device of the cable-driven joint module provided by the embodiments of the present application can achieve Figure 9 each process implemented by the method embodiments. To avoid repetition, it will not be elaborated here.

[0249] In some embodiments, as Figure 12 shown, the embodiments of the present application further provide an electronic device 1200, including a processor 1201, a memory 1202, and a computer program stored on the memory 1202 and executable on the processor 1201. When the program is executed by the processor 1201, it implements each process of the above-mentioned method embodiment for designing the cam profile of the cable-driven joint module, and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0250] It should be noted that the electronic devices in the embodiments of the present application include the above-mentioned mobile electronic devices and non-mobile electronic devices.

[0251] The embodiments of the present application further provide a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements each process of the above-mentioned method embodiment for designing the cam profile of the cable-driven joint module, and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0252] Wherein, the processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory ROM, random access memory RAM, magnetic disks, or optical discs, etc.

[0253] The embodiments of the present application further provide a computer program product, including a computer program. When the computer program is executed by a processor, it implements the above-mentioned method for designing the cam profile of the cable-driven joint module.

[0254] Wherein, the processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory ROM, random access memory RAM, magnetic disks, or optical discs, etc.

[0255] The embodiments of the present application further provide a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement each process of the above-mentioned method embodiment for designing the cam profile of the cable-driven joint module, and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0256] It should be understood that the chip mentioned in the embodiments of the present application may also be referred to as a system-on-chip, system chip, chip system, or system-on-chip, etc.

[0257] It should be noted that, in this text, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising that element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0258] From the description of the above embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. The computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disc) and includes several instructions for causing a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present application.

[0259] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0260] In the description of the present application, the "first feature" and "second feature" may include one or more of such features.

[0261] In the description of the present application, the meaning of "a plurality of" is two or more.

[0262] In the description of the present application, the first feature being "above" or "below" the second feature may include direct contact between the first and second features, or may include indirect contact between the first and second features through additional features therebetween.

[0263] In the description of the present application, the first feature being "above", "over" or "on top of" the second feature includes the first feature being directly above or obliquely above the second feature, or simply indicating that the first feature has a higher horizontal height than the second feature.

[0264] In the description of this specification, the description of reference terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0265] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. A rope-driven joint module, characterized in that Comprising: A first joint portion and a second joint portion; A drive module, wherein the second joint portion is rotatably connected to the first joint portion through the drive module. The drive module includes a drive motor, a transmission mechanism, and a pair of drive ropes. The pair of drive ropes includes two drive ropes. The transmission mechanism includes a rotating wheel and two driven members. The rotating wheel is connected to the output end of the drive motor. A cam is provided on each side of the rotating wheel. The cam contacts the driven member, and the rotation of the cam causes the driven member to perform a reciprocating motion; One end of the drive rope is connected to the second joint portion, and the other end of the drive rope passes through a through hole on the end face of the first joint portion and is connected to the cam. The curvature of the cam is positive. The drive rope passes through the portion where the cam contacts the driven member, and the drive rope is wound around the cam; Wherein, the drive motor is used to drive the rotating wheel to rotate, drive one of the cams to draw in one of the drive ropes in the pair of drive ropes, and drive the other cam to release the other drive rope in the pair of drive ropes, so as to realize the rotational freedom of the second joint portion along the direction of the line connecting the two connection points of the two drive ropes and the first joint portion.

2. The cable-driven joint module according to claim 1, characterized in that, The end of the first joint portion facing the second joint portion is a plane, and the end of the second joint portion facing the first joint portion is a plane.

3. The cable-driven joint module according to claim 1, characterized in that The transmission mechanism further includes two tension pre-tightening devices corresponding to the two drive ropes one by one. The tension pre-tightening devices are located between the driven member and the end face of the first joint portion, and the tension pre-tightening devices contact the drive ropes.

4. The cable-driven joint module according to claim 3, characterized in that, Further comprising: Two tension sensors corresponding to the two drive ropes one by one. The tension sensors are located between the tension pre-tightening devices and the end face of the first joint portion. The tension sensors contact the drive ropes, and the tension sensors are used to detect the tension of the drive ropes.

5. The cable-driven joint module according to claim 1, characterized in that The displacement range of the reciprocating motion of the driven member is determined based on the profile parameters of the cam.

6. The cable-driven joint module according to any one of claims 1-5, characterized in that, The drive module further includes: A limiting mechanism, which is arranged at the connection between the rotating wheel and the output end of the drive motor. The limiting mechanism is used to limit the position of the rotating wheel so that the zero position of the cam is aligned with the zero position of the second joint portion.

7. The cable-driven joint module according to any one of claims 1-5, characterized in that, The distance between the center point of the rotation of the second joint portion and the connection point of the drive rope and the first joint portion is a first distance; When the second joint portion is in the zero position, the length of the drive rope exposed from the end of the second joint portion is a second distance; Wherein, the ratio of the first distance to the second distance is 1 / 3 - 2 / 3.

8. The cable-driven joint module according to any one of claims 1-5, characterized in that, Further comprising: A first encoder, which is arranged on one of the second joint portion or the first joint portion. The first encoder is used to detect the joint rotation angle of the second joint portion relative to the first joint portion; A second encoder, which is arranged on the drive motor. The second encoder is used to detect the motor rotation angle of the rotating wheel.

9. A robotic arm, characterized in that, Comprising: At least one cable-driven joint module according to any one of claims 1-8.

10. A robot, characterized in that, Comprising: At least one robotic arm according to claim 9.

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