Joint device of robot hand, joint system and control method thereof

Abstract

The application discloses a joint device of a mechanical hand, a joint system and a control method thereof, and belongs to the technical field of robots. The joint device of the mechanical hand comprises a fixed base, a connecting support, a multi-degree-of-freedom supporting structure, a rope transmission assembly and a driving assembly. Since the two ends of the multi-degree-of-freedom supporting structure are movably connected with the fixed base and the connecting support respectively, the bending degree of freedom of the joint device of the mechanical hand is improved. Moreover, the driving assembly can drive the multi-degree-of-freedom supporting structure and the connecting support to move to a preset position through the rope transmission assembly, and the rope transmission assembly is always kept in a tension state, so that the influence of the relaxation of the rope transmission assembly on the transmission accuracy is reduced, and the accuracy and stability of the driving assembly in driving the connecting support to move through the rope transmission assembly are improved.

Description

Technical Field

[0001] This application relates to the field of robotics, and in particular to a joint device, joint system and control method for a robotic hand. Background Technology

[0002] With the development of robotics technology, the requirements for the precision of robot operations are becoming increasingly stringent. As the end effector for embodied robots to interact with their environment, dexterous hands can endow robots with functions approaching those of a human hand, enabling them to perform precise operations such as grasping, assembly, and repair. This not only enhances the practicality and adaptability of robots but also broadens their application scope in industries such as manufacturing and medicine.

[0003] Currently, robotic manipulators consist of multiple joints, which are typically driven by various methods such as direct motor drive, linkage transmission, gear / worm gear transmission, pneumatic / hydraulic transmission, and chord drive. Chord-driven robotic dexterous hands, with their low inertia, ease of adjustment, lightweight design, and interactive nature, have become a commonly used joint drive method.

[0004] However, the joints in current rope-driven robotic manipulators have low stability, resulting in limited applicability of the robotic manipulators. Summary of the Invention

[0005] This application provides a joint device, joint system, and control method for a robotic hand. It addresses the problem of low load-bearing capacity in the joints of existing rope-driven robot dexterous hands, which limits their applicability. The technical solution is as follows:

[0006] According to one aspect of this application, a joint device for a robotic hand is provided, the joint device comprising:

[0007] Fixed base, connecting support, multi-degree-of-freedom support structure, rope transmission assembly and drive assembly;

[0008] The fixed base is disposed opposite to the connecting support;

[0009] The multi-degree-of-freedom support structure is located between the fixed base and the connecting support, and its two ends are movably connected to the fixed base and the connecting support, respectively.

[0010] The rope drive assembly is connected to the connecting support and the drive assembly respectively;

[0011] The drive assembly is configured to drive the multi-degree-of-freedom support structure and the connecting support to a preset position via the rope drive assembly, and to keep the rope drive assembly taut at all times.

[0012] Optionally, the multi-degree-of-freedom support structure includes multiple connecting shafts;

[0013] The first ends of the plurality of connecting shafts are all movably connected to the fixed base and arranged around the center of the fixed base; the second ends of the plurality of connecting shafts are all movably connected to the connecting support and arranged around the center of the connecting support.

[0014] Any two of the connecting axes are arranged in a cross pattern.

[0015] Optionally, the connecting shaft includes a first shaft and a second shaft connected together, wherein the end of the first shaft opposite to the second shaft is movably connected to the fixed base, and the end of the second shaft opposite to the first shaft is movably connected to the connecting support.

[0016] The first shaft and the second shaft have an obtuse angle between them, pointing toward the other connecting shaft.

[0017] Optionally, the rope drive assembly includes a rope winding member and an annular rope body;

[0018] One of the rope winding components is fixed to the fixed base, and the other rope winding component is fixed to the connecting support;

[0019] The annular rope is wound around the rope winding member and connected to the drive assembly.

[0020] Optionally, the rope winding component includes a first winding post and a second winding post;

[0021] The first winding post is distributed around the fixed base and is fixedly connected to the fixed base;

[0022] The second winding post is distributed around the connecting support and is fixedly connected to the connecting support;

[0023] The ring-shaped rope is wound multiple times on the first winding post and the second winding post.

[0024] Optionally, the drive assembly can change the tension of the annular rope by rotating it at a certain angle;

[0025] The drive assembly includes a torque motor, a reel, and a bollard.

[0026] The torque motor is connected to the winding reel;

[0027] The bollard is fixedly installed on the reel, and the annular rope has a knot, which is sleeved on the bollard.

[0028] The torque motor drives the winding wheel to rotate in order to adjust the tension of the annular rope.

[0029] Optionally, the fixed base includes a first annular support, and the connecting support includes a second annular support.

[0030] According to another aspect of this application, a joint system for a robotic hand is provided, the joint system comprising: a joint device for the robotic hand and a control component, the joint device for the robotic hand comprising the joint device for the robotic hand described above, and the control component being electrically connected to the drive component;

[0031] The control component has a first relationship table pre-stored. The first relationship table is used to reflect the correspondence between position information and rotation angle. The position information is the position coordinate of the connecting support with the center of the fixed base as the origin. The rotation angle is the rotation angle of the drive component.

[0032] The control component is used to obtain the rotation angle corresponding to the target position information from the first relationship table according to the acquired target position information, and drive the drive component based on the rotation angle corresponding to the target position information.

[0033] According to another aspect of this application, a joint control method for a robotic arm is provided for the aforementioned joint system of the robotic arm, the method comprising:

[0034] The control component acquires target location information;

[0035] The control component obtains the rotation angle of the drive component corresponding to the target position information from the first relationship table;

[0036] The control component drives the drive component to rotate based on the rotation angle corresponding to the target position information;

[0037] The drive assembly loosens or tightens the rope transmission assembly when it rotates.

[0038] When the rope drive assembly is relaxed or tightened, it drives the multi-degree-of-freedom support structure and the connecting support to move, and drives the connecting support to move to the position corresponding to the target position information;

[0039] The control component controls the drive component to stop rotating.

[0040] Optionally, the drive assembly includes a first drive assembly and a second drive assembly, and the rope transmission assembly includes a first rope transmission assembly and a second rope transmission assembly. The first drive assembly is used to drive the rope transmission assembly to tighten, and the second drive assembly is used to drive the rope transmission assembly to relax, so as to drive the multi-degree-of-freedom support structure and the connecting support to move.

[0041] After the control component controls the drive component to stop rotating, the method further includes:

[0042] The control component controls the second drive component to rotate in the opposite direction until the torques of both the second drive component and the first drive component reach the stall torque, at which point the rotation of the second drive component stops.

[0043] The beneficial effects of the technical solutions provided in this application include at least the following:

[0044] 1) This application provides a joint device for a robot arm, including a fixed base, a connecting support, a multi-degree-of-freedom support structure, a rope transmission assembly, and a drive assembly. Since the two ends of the multi-degree-of-freedom support structure are movably connected to the fixed base and the connecting support, respectively, when the rope transmission assembly drives the connecting support to rotate, the multi-degree-of-freedom support structure can also tilt and rotate. This increases the range of motion and bending freedom of the multi-degree-of-freedom support structure, thereby improving the bending freedom of the robot arm's joint device. Furthermore, the drive assembly can drive the multi-degree-of-freedom support structure and the connecting support to a preset position via the rope transmission assembly, and keep the rope transmission assembly taut at all times to reduce the impact of slack on transmission accuracy. That is, the drive assembly only stops rotating when it reaches a stall state, thus ensuring that the rope transmission assembly is always taut, improving the accuracy and stability of the drive assembly driving the connecting support through the rope transmission assembly.

[0045] 2) By tilting and intersecting multiple connecting shafts in the multi-degree-of-freedom support structure, the multi-degree-of-freedom support structure can be rotated in multiple directions.

[0046] 3) Any connecting shaft has an obtuse angle between its first and second shafts, pointing towards other connecting shafts. On the one hand, by bending multiple connecting shafts, mutual interference between them during operation can be avoided. On the other hand, when the multi-degree-of-freedom support structure drives the connecting support to rotate to its limit position, the bending points of multiple connecting shafts (that is, the connection points of the first and second shafts) can overlap each other to form an integral lever structure, thereby enhancing the load-bearing capacity of the multi-degree-of-freedom support structure and improving the stability of the manipulator's joint device.

[0047] 4) During the process of the drive assembly pulling the multi-degree-of-freedom support structure and connecting support via the loop rope, the force can be transmitted jointly by the two strands of rope, thereby improving the load-bearing capacity of the manipulator's joint device. Furthermore, since the loop rope is fixedly connected to the drive assembly while also being wound around the winding member, the load-bearing force generated when the loop rope pulls the multi-degree-of-freedom support structure and connecting support can be distributed to multiple locations on the loop rope. These multiple locations can include the connection point between the loop rope and the drive assembly, as well as the connection point between the loop rope and the winding member. This reduces stress concentration on the loop rope, thereby improving its load-bearing capacity and, consequently, the load-bearing capacity of the manipulator's joint device.

[0048] 5) By winding the looped rope around the non-rotating first and second winding posts, the error caused by installation gaps can be reduced compared to pulleys in related technologies, thereby improving the rotational accuracy of the joint device of the rotating axis manipulator. Furthermore, the contact surfaces of the looped rope and the winding member are relatively smooth, reducing friction between the looped rope and the winding member during relative movement and lowering drive energy loss.

[0049] 6) The torque motor can obtain its own rotational torque to determine whether it is in a stalled state. The knots on the loop rope can be fitted onto the bollards to achieve an anti-detachment connection between the loop rope and the drive assembly.

[0050] 7) Both the first and second annular supports can be hollow structures, which can reduce the interference of the wire harness assembly on the multi-degree-of-freedom support structure and connecting supports when the joint rotates. It can also improve the neatness and aesthetics of the wire harness assembly, thereby improving the operational stability and aesthetics of the joint device of the robot.

[0051] 8) The control component has a pre-stored first relationship table, which reflects the correspondence between position information and rotation angle. The control component controls the rotation angle of the drive component by looking up the table, which can improve the running accuracy of the joint system of the robot.

[0052] 9) By rotating at least one torque motor in the opposite direction, the control accuracy of the robot's joint device may be reduced due to changes in preload during movement, thereby improving the control accuracy and response speed of the robot's joint device system. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of the joint device of a robotic arm provided in an embodiment of this application;

[0055] Figure 2 yes Figure 1 A schematic diagram of the joint mechanism of the robotic arm from another perspective;

[0056] Figure 3 yes Figure 1 A schematic diagram of the joint mechanism of the robotic arm from another perspective;

[0057] Figure 4 A schematic diagram illustrating the movement direction of a joint device of a robotic arm, provided in an embodiment of this application;

[0058] Figure 5 This is a schematic diagram of the structure of a ring-shaped rope provided in an embodiment of this application;

[0059] Figure 6 This is a partial structural schematic diagram of the joint device of a robotic arm provided in an embodiment of this application;

[0060] Figure 7 yes Figure 6 An exploded view of the joint mechanism of the robotic arm shown.

[0061] Figure 8 This is a schematic diagram of the projection structure of a multi-degree-of-freedom support structure on a fixed base provided in an embodiment of this application;

[0062] Figure 9 This is a schematic diagram of a connecting shaft provided in an embodiment of this application;

[0063] Figure 10 This is a schematic diagram of the connection structure between a drive component and an annular rope provided in an embodiment of this application;

[0064] Figure 11 This is a flowchart of a joint control method provided in an embodiment of this application. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0066] Although this application can readily be embodied in various forms, only some specific embodiments are shown in the accompanying drawings and will be described in detail in this specification. It is understood that this specification should be regarded as an exemplary illustration of the principles of this application and is not intended to limit the application to what is described herein.

[0067] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of this application, and does not imply that every embodiment of this application must have the described feature. Furthermore, it should be noted that this specification describes many features. While certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0068] In the embodiments shown in the accompanying drawings, the directional indications (such as up, down, left, right, front, and back) used to explain the structure and movement of the various elements of this application are relative rather than absolute. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the description of the positions of these elements changes, these directional indications also change accordingly.

[0069] Please refer to Figures 1 to 3 , Figure 1 This is a schematic diagram of the joint device 10 of a robotic arm provided in an embodiment of this application. Figure 2 yes Figure 1 The diagram shows another view of the joint device 10 of the robotic arm. Figure 3 yes Figure 1 The diagram shows another structural view of the joint device 10 of the robotic arm. The joint device 10 may include: a fixed base 11, a connecting support 15, a multi-degree-of-freedom support structure 12, a cable transmission assembly 13, and a drive assembly 14. The joint device 10 of the robotic arm in this embodiment can be applied to robots.

[0070] The fixed base 11 and the connecting support 15 are arranged opposite to each other; the multi-degree-of-freedom support structure 12 is located between the fixed base 11 and the connecting support 15, and its two ends are movably connected to the fixed base 11 and the connecting support 15 respectively; the rope transmission assembly 13 is connected to the connecting support 15 and the drive assembly 14 respectively; the drive assembly 14 is configured to drive the multi-degree-of-freedom support structure 12 and the connecting support 15 to a preset position through the rope transmission assembly 13, and keep the rope transmission assembly 13 in a taut state at all times.

[0071] The fixed base 11 can be securely connected to other external mechanical structures to mount the joint device 10 of the robot arm. The connecting support 15 can be used to connect to other external mechanical structures.

[0072] Since the two ends of the multi-degree-of-freedom support structure 12 are movably connected to the fixed base 11 and the connecting support 15 respectively, when the rope transmission assembly 13 drives the connecting support 15 to rotate, the multi-degree-of-freedom support structure 12 can also tilt and rotate. In this way, the range of motion of the multi-degree-of-freedom support structure 12 can be increased. Compared with the universal joint structure, the multi-degree-of-freedom support structure 12 in this embodiment can increase the bending degree of the joint device 10 of the robot.

[0073] Furthermore, the drive assembly 14 can be in a stalled state after driving the connecting support 15 to a preset position via the rope transmission assembly 13, thereby tightening the rope transmission assembly 13 and ensuring that the rope transmission assembly 13 remains continuously taut. When the rope transmission assembly 13 has been used for a long time, it may become loose. In this embodiment, the drive assembly only stops rotating when it reaches the stalled state, thus ensuring that the rope transmission assembly 13 remains taut at all times. This improves the accuracy and stability of the drive assembly 14 when driving the connecting support 15 via the rope transmission assembly 13.

[0074] In one exemplary embodiment, the rope drive assembly 13 may include a first rope drive assembly, a second rope drive assembly, and a third rope drive assembly, and the drive assembly 14 may include a first drive assembly, a second drive assembly, and a third drive assembly. During the drive of the manipulator's joint device 10, the first drive assembly can rotate in a first direction to pull the first rope drive assembly fixedly connected to it, causing the first rope drive assembly to tighten under the pull of the first drive assembly. Simultaneously, the second and third drive assemblies can both rotate in a second direction to loosen the first rope drive assembly fixedly connected to them, causing the first rope drive assembly to loosen under the pull of the first drive assembly. Since the connecting support 15 is movably connected to the fixed base 11 via the multi-degree-of-freedom support structure 12, a pulling force towards the drive assembly 14 can be applied to the connecting support 15 through the first rope drive assembly, thereby causing the multi-degree-of-freedom support structure 12 to bend towards the first drive assembly, and subsequently causing the connecting support 15 located at one end of the multi-degree-of-freedom support structure 12 to rotate towards the first drive assembly.

[0075] Please refer to Figures 1 to 3Optionally, the rope drive assembly 13 includes a rope winding member 131 and an annular rope body 1312; one of the rope winding members 131 is fixed to the fixed base 11, and the other rope winding member is fixed to the connecting support 15. The annular rope body 1312 is wound around the rope winding member and connected to the drive assembly 14. During the process of the drive assembly 14 pulling the multi-degree-of-freedom support structure 121 and the connecting support 15 via the annular rope 1312, the force can be transmitted jointly by the two strands of rope, thereby improving the load-bearing capacity of the joint device 10 of the robot hand. Furthermore, since the annular rope 1312 is fixedly connected to the drive assembly 14 and also wound around a pair of rope members 131, the load-bearing force on the annular rope 1312 can be distributed to multiple connection points between the annular rope 1312 and the drive assembly 14 and the pair of rope members 131. This reduces stress concentration on the annular rope 1312, thereby improving its load-bearing capacity and consequently enhancing the load-bearing capacity of the joint device 10 of the robot hand. This solves the problem in related technologies where the load-bearing capacity of the joints in rope-driven robot dexterous hands is low, resulting in limited applicability of the robot dexterous hand.

[0076] For example, the joint device 10 of the robotic arm may include multiple pairs of rope winding members 131, multiple ring ropes 1312, and multiple drive components 14. The multiple pairs of rope winding members 131 may correspond one-to-one with the multiple ring ropes 1312, and the multiple ring ropes 1312 may correspond one-to-one with the multiple drive components 14. Any one ring rope 1312 is wound around the corresponding pair of rope winding members 131 and connected to the corresponding drive component 14.

[0077] Please continue to refer to this. Figure 4 , Figure 4 This is a schematic diagram illustrating the movement direction of the joint device 10 of a robotic arm provided in an embodiment of this application. It can be understood that... Figure 4To facilitate the illustration of the movement direction of the annular rope 1312, the torque motor 141 in the drive assembly 14 is not shown. During the process of the drive assembly 14 pulling the annular rope 1312, the two strands of rope fixedly connected to the drive assembly 14 in the annular rope 1312 move in the same direction. In this way, the load-bearing capacity of the joint device 10 of the robot can be improved by transmitting force through the two strands of rope. Furthermore, since the annular rope 1312 is fixedly connected to the drive assembly 14 and also wound around the winding member 131, the load-bearing force generated when the annular rope 1312 pulls the multi-degree-of-freedom support structure 121 and the connecting support 15 can be distributed to multiple locations of the annular rope 1312. These multiple locations may include the connection position between the annular rope 1312 and the drive assembly 14, and the connection position between the annular rope 1312 and the winding member 131. In this way, stress concentration on the annular rope 1312 can be reduced, thereby improving the load-bearing capacity of the annular rope 1312 and thus improving the load-bearing capacity of the joint device 10 of the robot.

[0078] In this embodiment, the rotation direction of the multi-degree-of-freedom support structure 121 and the connecting support 15 is adjusted by adjusting the tightness or looseness of multiple ropes through multiple drive components 14, thereby controlling the movement direction of the joint device 10 of the robot arm.

[0079] It should be noted that the rotation of the drive component 14 includes two cases: rotation around a first direction and rotation around a second direction. The first direction can be either clockwise or counterclockwise, and the second direction can be either clockwise or counterclockwise. The rotation direction of the drive component 14 can be determined based on the actual connection position between the drive component 14 and the annular rope 1312; this embodiment does not limit this.

[0080] It is understood that the loop rope 1312 includes an integral loop rope 1312 and a knotted loop rope 1312. For example, please refer to [reference needed]. Figure 4 and Figure 5 , Figure 5 This is a schematic diagram of the structure of an annular rope 1312 provided in an embodiment of this application. The annular rope 1312 may include a winding portion and a connecting portion. The winding portion can be wound around a rope member 131, and the connecting portion can be fixedly connected to a drive assembly 14. Alternatively, the annular rope 1312 includes a winding portion and a first end and a second end located at both ends of the winding portion. The first end and the second end are fixedly connected by knotting or bonding, so that the annular rope 1312 is in a loop shape. Alternatively, both the first end and the second end can be fixedly connected to the drive assembly 14, so it can be considered that the first end and the second end are also fixedly connected, so that the annular rope 1312 is in a loop shape.

[0081] Please refer to Figure 4 and Figure 6 , Figure 6 This is a partial structural schematic diagram of a joint device 10 for a robotic arm provided in an embodiment of this application. In an optional embodiment, any pair of rope winding members 131 may include a first winding post 1311 and a second winding post 1312; a plurality of first winding posts 1311 are distributed around a fixed base 11 and are fixedly connected to the fixed base 11; a plurality of second winding posts 1312 are distributed around a connecting support 15 and are fixedly connected to the connecting support 15; and an annular rope 1312 is wound multiple times around the first winding posts 1311 and the second winding posts 1312.

[0082] By winding the annular rope 1312 around the first winding post 1311 and the second winding post 1312, when the drive assembly 14 rotates and pulls and tightens the annular rope 1312, the annular rope 1312 wound around the first winding post 1311 and the second winding post 1312 can be tightened and the distance between the first winding post 1311 and the second winding post 1312 can be reduced. Thus, the first winding post 1311 and the second winding post 1312 drive the multi-degree-of-freedom support structure 121 and the connecting support 15 to rotate relative to the fixed base 11.

[0083] Thus, by winding the annular rope 1312 around the first winding post 1311 and the second winding post 1312, the load-bearing capacity of the annular rope 1312 can be distributed to the connection points between the annular rope 1312 and the first winding post 1311, as well as the connection points between the annular rope 1312 and the first winding post 1311, thereby balancing the load-bearing capacity of the annular rope 1312. Furthermore, since the annular rope 1312 can be wound multiple times around the first winding post 1311 and the second winding post 1312, when the annular rope 1312 drives the first winding post 1311 and the second winding post 1312 to move relative to each other, all multiple turns of the annular rope 1312 can pull the first winding post 1311 and the second winding post 1312, thereby increasing the load-bearing capacity of the joint device 10 of the robotic arm.

[0084] For example, the surfaces of the first winding post 1311 and the annular rope 1312 in contact with each other are relatively smooth, thereby making the contact surfaces of the annular rope 1312 and the winding member 131 relatively smooth. This reduces the friction between the annular rope 1312 and the winding member 131 during the relative movement of the annular rope 1312 and the winding member 131, thus reducing the loss of driving energy.

[0085] In one exemplary embodiment, the rope winding member 131 may include a first winding pulley and a second winding pulley. By winding the rope around the first and second winding pulleys, the difficulty of moving the rope is reduced. Since the winding pulley includes a wheel body and a rotating shaft, there is an installation gap between the wheel body and the rotating shaft. This gap affects the movement accuracy of the rope wound on the pulley during movement, which may affect the accuracy of the rope drive structure. In this embodiment, by winding the annular rope 1312 around the non-rotating first winding post 1311 and the non-rotating second winding post 1312, compared to the pulleys in related technologies, the first winding post 1311 and the second winding post 1312 are fixedly connected to the fixed base 11 and the connecting support 15, respectively. This reduces the error caused by the installation gap, thereby improving the rotation accuracy of the joint device 10 of the rotating shaft manipulator.

[0086] In one exemplary embodiment, the material of the annular rope 1312 may include a tungsten-molybdenum alloy to improve the load-bearing capacity of the annular rope 1312.

[0087] Please refer to Figure 6 , Figure 7 and Figure 8 , Figure 7 yes Figure 6 The diagram shows an exploded view of the joint device 10 of the robotic arm. Figure 8 This is a schematic diagram of the projection structure of a multi-degree-of-freedom support structure 12 on a fixed base 11 according to an embodiment of this application. In an optional embodiment, the multi-degree-of-freedom support structure 12 may include multiple connecting shafts 121; the first ends of the multiple connecting shafts 121 are all movably connected to the fixed base 11 and arranged around the center of the fixed base 11; the second ends of the multiple connecting shafts 121 are all movably connected to the connecting support 15 and arranged around the center of the connecting support 15; any two connecting shafts 121 are arranged in a cross pattern.

[0088] When the joint device 10 of the robot arm is not rotating, any one of the connecting shafts 121 can be tilted relative to the fixed base 11, and the tilting degree of multiple connecting shafts 121 can be kept consistent.

[0089] like Figure 8 As shown, in the direction perpendicular to the fixed base 11, the orthographic projections of the first ends and the second ends of the multiple connecting shafts 121 onto the fixed base 11 can be arranged alternately. Furthermore, the orthographic projection of the first end of any connecting shaft 121 onto the fixed base 11 lies between the orthographic projections of the second ends of the other two connecting shafts 121 onto the fixed base 11. Thus, by tilting and intersecting the multiple connecting shafts 121, a multi-degree-of-freedom support structure can be rotated in multiple directions.

[0090] Please refer to Figure 7 and Figure 9 , Figure 9 This is a schematic diagram of the structure of a connecting shaft 121 provided in an embodiment of this application. In an optional embodiment, any one of the connecting shafts 121 can be bent in a direction away from other connecting shafts 121. The connecting shaft 121 may include a first shaft body t1 and a second shaft body t2 connected together. The end of the first shaft body t1 opposite to the second shaft body t2 is movably connected to a fixed base 11, and the end of the second shaft body t2 opposite to the first shaft body t1 is movably connected to a connecting support 15. The first shaft body t1 and the second shaft body t2 have an obtuse angle α between them, pointing towards other connecting shafts 121. This configuration has two advantages: firstly, by bending multiple connecting shafts 121, mutual interference between them during operation can be avoided; secondly, when the multi-degree-of-freedom support structure drives the connecting support 15 to rotate to its limit position, the bending positions of the multiple connecting shafts 121 (that is, the connection position of the first shaft t1 and the second shaft t2) can overlap each other to form an integral lever structure, thereby enhancing the load-bearing capacity of the multi-degree-of-freedom support structure and improving the stability of the joint device 10 of the robot arm.

[0091] In one exemplary embodiment, the included angle α between the first shaft t1 and the second shaft t2 can range from 130° to 150°. For example, the included angle α between the first shaft t1 and the second shaft t2 can be 130°, 135°, 140°, 142°, 148°, or 150°.

[0092] Please refer to Figure 6 and Figure 7 In one optional embodiment, the fixed base 11 may include a first annular support 111, and the connecting support 15 may include a second annular support 151. A plurality of connecting shafts 121 may be located between the first annular support 111 and the second annular support 151, and are rotatably connected to the first annular support 111 and the second annular support 151, respectively.

[0093] For example, both ends of any connecting shaft 121 can be rotatably connected to the first annular support 111 and the second annular support 151 via a rotating shaft z1. The rotating shaft z1 can be rotatably connected to either the first annular support 111 or the second annular support 151, and the rotating shaft z1 can rotate along a first axis, which can be parallel to the circumference of the second annular support 151. The connecting shaft 121 can be rotatably connected to the rotating shaft z1, and the connecting shaft 121 can rotate along a second axis, which can be parallel to the radial direction of the second annular support 151.

[0094] Both the first annular support 111 and the second annular support 151 can be hollow structures, and the shapes of the first annular support 111 and the second annular support 151 are similar, which can improve the symmetry and stability of the joint device 10 of the robot hand, and also reduce the overall weight of the joint device 10 of the robot hand.

[0095] The joint device 10 of the robotic arm may also include a wiring harness assembly. The wiring harness assembly can pass through the hollow areas of the first annular support 111 and the second annular support 151 and be electrically connected to the drive assembly 14. In this way, the wiring harness assembly can be built into the joint device 10 of the robotic arm, which can reduce the interference of the wiring harness assembly on the multi-degree-of-freedom support structure 121 and the connecting support 15 when the joint rotates, and can also improve the neatness and aesthetics of the wiring harness assembly, thereby improving the operational stability and aesthetics of the joint device 10 of the robotic arm.

[0096] In one optional embodiment, a plurality of first winding posts 1311 may be evenly distributed around a first annular support 111 and fixedly connected to the first annular support 111, and a plurality of second winding posts 1312 may be evenly distributed around a second annular support 151 and fixedly connected to the second annular support 151. For example, the number of both first winding posts 1311 and second winding posts 1312 is three.

[0097] The fixed base 11 may further include a plurality of first connecting posts 112, which are evenly distributed around the first annular support 111 and fixedly connected to the first annular support 111. The connecting support 15 may further include a plurality of second connecting posts 152, which are evenly distributed around the second annular support 151 and fixedly connected to the second annular support 151. The plurality of first connecting posts 112 may be fixedly connected to a plurality of first winding posts 1311 in a one-to-one correspondence, and the plurality of second connecting posts 152 may be fixedly connected to a plurality of second winding posts 1312 in a one-to-one correspondence.

[0098] Please refer to Figure 2 and Figure 10 , Figure 10 This is a schematic diagram of the connection structure between a drive assembly 14 and an annular rope 1312 provided in an embodiment of this application. In an optional embodiment, the drive assembly 14 changes the tension of the annular rope 1312 by rotating at a certain angle. The drive assembly 14 may include a torque motor 141, a reel 142, and a bollard 143. The torque motor 141 and the reel 142 are fixedly connected. The bollard 143 is fixedly installed on the reel 142. The annular rope 132 has a knot 1321, which is sleeved on the bollard 143.

[0099] The torque motor 141 is capable of acquiring its own rotational torque; for example, the torque motor includes a torque servo motor. When the torque motor rotates, it can drive the winding wheel 142 to rotate, thereby adjusting the tension of the annular rope 1312.

[0100] The tether 143 can be L-shaped and can be located on the side of the reel 142. The connecting part on the rope can be a knot 1321, which can include a rabbit ear knot (also known as a double figure-eight knot).

[0101] In one exemplary embodiment, the tightening or loosening state of multiple annular ropes 1312 is adjusted by combining different rotation angle values ​​and rotation angular velocities of multiple torque motors, thereby driving the multi-degree-of-freedom support structure 121 and the connecting support 15 to rotate, so that the connecting support 15 rotates to the target position according to the target motion speed, thereby realizing motion control of the joint device 10 of the robot arm.

[0102] This application embodiment also provides a joint system, which may include: a joint device 10 of a robotic arm and a control component. The joint device 10 of the robotic arm includes the joint device 10 of the robotic arm in any of the above embodiments, and the control component is electrically connected to the drive component 14.

[0103] The control component has a first relationship table pre-stored. The first relationship table is used to reflect the correspondence between position information and rotation angle. The position information is the position coordinate of the support 15 when the center of the fixed base 11 is taken as the origin, and the rotation angle is the rotation angle of the drive component 14. The control component is used to obtain the rotation angle corresponding to the target position information from the first relationship table according to the obtained target position information, and drive the drive component 14 based on the rotation angle corresponding to the target position information.

[0104] The center of the fixed base 11 can be the geometric center point or the centroid point of the first annular support 111 in the fixed base 11, and the position coordinates of the connecting support 15 can refer to the position coordinates of the geometric center point or the centroid point of the second annular support 151.

[0105] The target position information can be user-inputted position information or pre-stored position information in the control component. The first relationship table can show the correspondence between multiple position information and multiple rotation angles. Multiple position information can represent different positions that the joint device 10 of the robot can rotate to. The target position information can be one of the multiple position information.

[0106] Thus, by controlling the forward and reverse rotation of the torque motor in the drive assembly 14 and the rotation angle of the torque motor, the connecting support 15 can be rotated to the target position.

[0107] Please refer to Figure 11 , Figure 11 This is a flowchart of a joint control method provided in an embodiment of this application. The joint control method can be used in the joint system described in the above embodiments, and the method may include the following steps:

[0108] Step 201: The control component obtains the target location information.

[0109] After starting the joint system, the user can set the coordinate system of the joint device 10 of the robot before rotation in the control system. For example, the center of mass of the first annular support 111 can be preset as the origin of the coordinate system (X0, Y0, Z0), the XY plane of the coordinate axis is parallel to the annular disk surface of the first annular support 111, the Z axis is perpendicular to the annular disk surface of the first annular support 111, the X axis is parallel to the rotation axis of the winding wheel 142, and the Y axis forms a 90° angle with the X axis.

[0110] The joint system may also include a terminal that can be electrically connected to the control components, through which the user can input the target position information (X) of the joint device 10 of the robotic arm in this round of movement. t Y t Z t That is, the joint device 10 of the robotic arm needs to rotate so that the spatial position coordinates of the center of mass of the second annular support 151 relative to the center of mass (X0, Y0, Z0) of the first annular support 111 are (X0, Y0, Z0). t Y t Z t ).

[0111] Step 202: The control component obtains the target's maximum movement speed.

[0112] The target's maximum moving speed S t The maximum linear velocity S of the center of mass of the second annular support 151 when it moves from the current position to the target position. t .

[0113] Step 203: The control component obtains the rotation angle corresponding to the target position information from the first relation table.

[0114] The first relationship table can be a mapping relationship table between multiple physical quantities obtained through simulation experiments. These multiple physical quantities may include: position information, the distance between the first winding post 1311 and the second winding post 1312 in each group of winding components 131, the tightness of multiple loop ropes 1312 (that is, the degree of tightening or loosening of multiple loop ropes 1312), and the rotation angle of multiple torque motors.

[0115] For example, the control component can obtain the target location information (X) from the first relationship table. t Y t Z t The distances between the first winding post 1311 and the second winding post 1312 in the three sets of winding components 131 are (d1, d2, d3).

[0116] Since the distance values ​​(d1, d2, d3) between the first winding post 1311 and the second winding post 1312 in the three sets of winding components 131 correspond one-to-one with the tension values ​​(h1, h2, h3) of the three loop ropes 1312, the control component can obtain the tension values ​​(h1, h2, h3) of the three loop ropes 1312 corresponding to the distance values ​​(d1, d2, d3) from the first relationship table.

[0117] Since the tension values ​​(h1, h2, h3) of the three loop ropes 1312 are determined by the rotation angles of the three torque motors respectively, the control component can obtain the rotation angles (θ1, θ2, θ3) of the three torque motors corresponding to the tension values ​​(h1, h2, h3) from the first relationship table.

[0118] Alternatively, a direct correspondence between position information and rotation angle can be established to directly obtain the rotation angle based on the target position information input by the user.

[0119] Step 204: The control component obtains the maximum angular velocity corresponding to the target's maximum moving speed from the second relation table.

[0120] The second relationship table reflects the correspondence between the maximum moving speed and the maximum angular velocity. The maximum moving speed is the maximum speed during the process of moving from the center of mass of the first annular support 111 to the target position, and the maximum angular velocity is the maximum angular velocity of the torque motor 141. The control component can obtain the value of the maximum moving speed S from the second relationship table. t The maximum angular velocity of the three torque motors 141 is used as the maximum angular velocity V corresponding to the target's maximum moving speed. t .

[0121] Understandably, when the target location information or the target maximum movement speed cannot be found in the first relation table, the location information with the smallest difference from the target location information and the maximum movement speed with the smallest difference from the target maximum movement speed can be used as the query results.

[0122] Steps 201 and 202 can be performed simultaneously, and steps 203 and 204 can be performed simultaneously.

[0123] Step 205: The control component drives the drive component 14 based on the rotation angle corresponding to the target position information.

[0124] The control component can control the angular velocity of the three torque motors to accelerate from 0 to the maximum angular velocity Vt, and control the three torque motors to rotate to the corresponding rotation angles (θ1, θ2, θ3).

[0125] Step 206: When the drive assembly 14 rotates, the rope transmission assembly 13 is loosened or tightened.

[0126] In one alternative embodiment, the plurality of drive components 14 may include a first drive component and a second drive component, and the plurality of annular ropes 1312 may include a first annular rope and a second annular rope. The first drive component is used to tighten the first annular rope, and the second drive component is used to loosen the second annular rope, so as to drive the multi-degree-of-freedom support structure 121 and the connecting support 15 to rotate.

[0127] Step 207: When the rope drive assembly 13 is relaxed or tightened, it drives the multi-degree-of-freedom support structure 12 and the connecting support 15 to move, and drives the connecting support 15 to the position corresponding to the target position information.

[0128] The multiple drive components 14 may include at least one first drive component and at least one second drive component, and the multiple annular ropes 1312 may include at least one first annular rope and at least one second annular rope. For example, the three drive components 14 include one first drive component and two second drive components, and the three annular ropes 1312 include one first annular rope and two second annular ropes. One first drive component tightens a corresponding first annular rope, while the two second drive components respectively loosen the two second annular ropes. This adjusts the distance between the first winding post 1311 and the second winding post 1312 in the multiple pairs of winding members 131 through the multiple annular ropes 1312, thereby causing the multi-degree-of-freedom support structure 121 and the connecting support 15 to rotate, such that the spatial coordinates of the center of mass of the second annular support 151 relative to the center of mass (X0, Y0, Z0) of the first annular support 111 are (X... t Y t Z t ).

[0129] During the aforementioned motion process, the torque motor in the first drive assembly can rotate in the first direction, and the torque motor in the second drive assembly can rotate in the second direction. That is, the rotation directions of the torque motors in different drive assemblies 14 may be opposite.

[0130] Step 208: The control component controls the drive component 14 to stop rotating.

[0131] When the connecting support 15 rotates to the target position, the control component can stop the rotation of the torque motors in the multiple drive components 14.

[0132] Step 209: The control component controls the second drive component to rotate in the opposite direction until the torques of both the second drive component and the first drive component reach the stall torque, and then stops the rotation of the second drive component.

[0133] Since the loop rope 1312 may loosen after prolonged use of the joint device 10 of the robotic arm, a preset angular velocity V can be installed after all three torque motors in the three drive components 14 have reached the rotation angle (θ1, θ2, θ3). s The two torque motors in the two second drive components are rotated in the reverse direction, causing them to tighten the corresponding annular ropes 1312. Since the first torque motor in the first drive component is not rotating at this time, the torque motors in the two second drive components will tighten the corresponding annular ropes 1312, and the torque motor in the first drive component will generate a reverse pulling force, thus tauting all the annular ropes 1312 until the torque of both the second and first drive components reaches the stall torque, stopping the rotation of the second drive component. The stall torque can range from 0.5N to 1.5N, and the reverse rotation speed can be from 0.7 rpm to 0.9 rpm. Stall torque, also known as stall torque, refers to the maximum torque that the motor can withstand under certain voltage and frequency when the rotor is stalled at all angles (i.e., the motor shaft is locked by external force) during operation. It can also be understood as the motor quickly stopping or failing to start when the counter-torque generated by the load resistance exceeds the electromagnetic torque of the motor; the torque that the motor can output at this time is the stall torque.

[0134] In this way, by rotating at least one torque motor in the opposite direction, the control accuracy of the joint device 10 of the robot arm may be reduced due to changes in preload during movement, thereby improving the control accuracy and response speed of the joint device 10 system of the robot arm.

[0135] The joint system in this embodiment maintains the characteristics of low inertia, light weight, and high load-to-weight ratio of the rope-driven structure. By combining the double-strand wire attachment technology of the loop rope 15 with the corresponding control algorithm, the accuracy and stability of the joint device 10 during movement can be improved. Furthermore, by winding the loop rope 15 around the rope member 13 multiple times, the joint device 10 can withstand greater loads and is suitable for more heavy-duty robot operation scenarios. In addition, the accuracy of the preload of the multiple loop ropes 15 is improved by using a reverse rotation motor, making the joint system more stable and reliable.

[0136] In this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0137] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0138] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A joint device for a robotic hand, characterized in that, include: Fixed base, connecting support, multi-degree-of-freedom support structure, rope transmission assembly and drive assembly; The fixed base is disposed opposite to the connecting support; The multi-degree-of-freedom support structure is located between the fixed base and the connecting support, and its two ends are movably connected to the fixed base and the connecting support, respectively. The rope drive assembly is connected to the connecting support and the drive assembly respectively; The drive assembly is configured to drive the multi-degree-of-freedom support structure and the connecting support to a preset position via the rope drive assembly, and to keep the rope drive assembly taut at all times. The rope drive assembly includes multiple pairs of rope winding components and multiple ring-shaped ropes; One of the rope winding components in any pair is fixed to the fixed base, and the other rope winding component is fixed to the connecting support; The multiple looped ropes are wound one-to-one around the multiple pairs of rope winding members, and are all connected to the drive assembly; Any pair of the aforementioned winding components includes a first winding post and a second winding post; Multiple first winding posts are distributed around the fixed base, and the first winding posts are fixedly connected to the fixed base; Multiple second winding posts are distributed around the multi-degree-of-freedom support structure, and the second winding posts are fixedly connected to the connecting support. The annular rope is wound multiple times on the first winding post and the second winding post; The drive assembly changes the tension of the annular rope by rotating it at a certain angle. The drive assembly includes a torque motor, a reel, and a bollard. The torque motor is connected to the winding reel; The bollard is fixedly installed on the reel, and the annular rope has a knot, which is sleeved on the bollard. The torque motor drives the winding wheel to rotate in order to adjust the tension of the annular rope.

2. The joint device of the robotic arm according to claim 1, characterized in that, The multi-degree-of-freedom support structure includes multiple connecting shafts; The first ends of the plurality of connecting shafts are all movably connected to the fixed base and arranged around the center of the fixed base; the second ends of the plurality of connecting shafts are all movably connected to the connecting support and arranged around the center of the connecting support. Any two of the connecting axes are arranged in a cross pattern.

3. The joint device of the robotic hand according to claim 2, characterized in that, The connecting shaft includes a first shaft and a second shaft, the end of the first shaft opposite to the second shaft is movably connected to the fixed base, and the end of the second shaft opposite to the first shaft is movably connected to the connecting support. The first shaft and the second shaft have an obtuse angle between them, pointing toward the other connecting shaft.

4. The joint device of the robotic arm according to claim 1, characterized in that, The fixed base includes a first annular support, and the connecting support includes a second annular support.

5. A joint system for a robotic hand, characterized in that, include: A joint device and control component for a robotic arm, wherein the joint device of the robotic arm includes the joint device of the robotic arm according to any one of claims 1 to 4, and the control component is electrically connected to the drive component; The control component has a first relationship table pre-stored. The first relationship table is used to reflect the correspondence between position information and rotation angle. The position information is the position coordinate of the connecting support with the center of the fixed base as the origin. The rotation angle is the rotation angle of the drive component. The control component is used to obtain the rotation angle corresponding to the target position information from the first relationship table according to the acquired target position information, and drive the drive component based on the rotation angle corresponding to the target position information.

6. A joint control method for a robotic arm, characterized in that, The method for the joint system of the robotic hand according to claim 5 includes: The control component acquires target location information; The control component obtains the rotation angle of the drive component corresponding to the target position information from the first relationship table; The control component drives the drive component to rotate based on the rotation angle corresponding to the target position information; The drive assembly loosens or tightens the rope transmission assembly when it rotates. When the rope drive assembly is relaxed or tightened, it drives the multi-degree-of-freedom support structure and the connecting support to move, and drives the connecting support to move to the position corresponding to the target position information; The control component controls the drive component to stop rotating.

7. The method according to claim 6, characterized in that, The drive assembly includes a first drive assembly and a second drive assembly, and the rope transmission assembly includes a first rope transmission assembly and a second rope transmission assembly. The first drive assembly is used to drive the rope transmission assembly to tighten, and the second drive assembly is used to drive the rope transmission assembly to relax, so as to drive the multi-degree-of-freedom support structure and the connecting support to move. After the control component controls the drive component to stop rotating, the method further includes: The control component controls the second drive component to rotate in the opposite direction until the torques of both the second drive component and the first drive component reach the stall torque, at which point the rotation of the second drive component stops.

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