End effector with gripping and twisting functions and its control method

Abstract

This application provides an end effector with gripping and twisting functions and its control method. The end effector includes: a fixed support, and a gripping mechanism, a linear assembly, and a twisting assembly disposed on the fixed support; the gripping mechanism includes multiple gripping claws distributed circumferentially, the twisting assembly is located on the central axis of the multiple gripping claws, and the linear assembly is used to drive the twisting assembly to move axially; wherein, after the gripping claws grip the element to be twisted, the end effector does not need to switch between the gripping mechanism and the twisting assembly, the linear assembly directly drives the twisting assembly to move axially, so that the twisting head of the twisting assembly engages with the interface of the element to be twisted, thereby the twisting assembly twists the element to be twisted. This application can continuously complete gripping and twisting operations in the confined space of a satellite without tool switching, solving the technical problem that existing end effectors are inefficient due to frequent tool changes and cannot adapt to the confined working space of satellites.

Description

Technical Field

[0001] This application mainly relates to the field of spacecraft on-orbit servicing technology, and in particular to an end effector with gripping and twisting functions and its control method. Background Technology

[0002] The end effector of a space robotic arm is a core component for performing on-orbit assembly, replacement, and maintenance. Its performance directly determines the operational capability and efficiency of on-orbit services. When performing on-orbit tasks involving both grasping and twisting operations, existing end effectors require the robotic arm to first mount a grasping end effector to complete the grasping operation, and then replace it with a twisting end effector, or another robotic arm to mount a twisting end effector to complete the operation. This process not only significantly increases the docking time and cost of on-orbit operations, but also significantly reduces operational efficiency because visual positioning and posture adjustment are required during tool changes.

[0003] Secondly, the satellite's internal structure is compact, with densely packed components and extremely limited clearance between devices. Within such a confined space, the end effector must meet stringent requirements for miniaturization and lightweight design. While some existing technologies integrate gripping and turning functions into a single end effector, these solutions often employ modular switching or quick-change connectors, adding extra rotational or adjustment degrees of freedom to achieve switching and alignment between different functional modules. The switching mechanism itself occupies valuable axial and radial space, resulting in an excessively large end effector that cannot access the narrow operating area inside the satellite.

[0004] In summary, there is an urgent need in this field for a space robotic arm end effector that can simultaneously perform grasping and twisting operations within the confined working space of a satellite, without the need for tool switching, and is compact and lightweight, in order to solve the technical problems of low operating efficiency, excessive size, and inability to adapt to the narrow working space of a satellite in the existing technology. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide an end effector with gripping and twisting functions and its control method, so as to solve the problem of how to continuously complete gripping and twisting operations in a narrow space without switching tools.

[0006] To address the aforementioned technical problems, this application provides an end effector with gripping and twisting functions, comprising: a fixed support, and a gripping mechanism, a linear assembly, and a twisting assembly disposed on the fixed support; the gripping mechanism includes multiple gripping claws distributed circumferentially, the twisting assembly is located on the central axis of the multiple gripping claws, and the linear assembly is used to drive the twisting assembly to move axially; wherein, after the gripping claws grip the element to be twisted, the end effector does not need to switch between the gripping mechanism and the twisting assembly, the linear assembly directly drives the twisting assembly to move axially, so that the twisting head of the twisting assembly engages with the interface of the element to be twisted, thereby the twisting assembly twists the element to be twisted.

[0007] In some embodiments, the gripping mechanism further includes: a first motor, a multifaceted columnar rack, and multiple sets of gear shafts and multiple sets of gears; the multiple sets of gear shafts are rotatably supported on the fixed support, the multiple sets of gears are respectively mounted on the multiple sets of gear shafts, the multiple sets of gears mesh with the multifaceted columnar rack, and multiple gripping claws are respectively fixedly mounted on the multiple sets of gear shafts; the first motor drives one set of gears to rotate, and transmits power synchronously to the other sets of gears through the multifaceted columnar rack, so as to drive the multiple gripping claws to open or close.

[0008] In some embodiments, the multifaceted columnar rack has multiple sides, and the sides of the multifaceted columnar rack that mesh with the gears are machined with meshing teeth. Each set of gears meshes with the meshing teeth on one side of the multifaceted columnar rack.

[0009] In some embodiments, the first motor is a power-off self-locking motor.

[0010] In some embodiments, the linear assembly includes: a second motor, a lead screw assembly, a support plate, and a linear bearing; the lead screw assembly is disposed on the fixed support, the support plate is fixedly connected to the output end of the lead screw assembly and one end of the linear bearing, and the other end of the linear bearing is fixedly connected to the screwing assembly; the second motor drives the lead screw assembly to move, causing the support plate and the linear bearing to slide axially, thereby causing the screwing assembly to move axially.

[0011] In some embodiments, the lead screw assembly includes a lead screw, a lead screw nut, and a lead screw mounting base. The lead screw is a trapezoidal lead screw with mechanical self-locking characteristics, which automatically locks the axial position of the linear bearing and the screwing assembly when the second motor is de-energized.

[0012] In some embodiments, there are two linear bearings, and the linear assembly further includes two linear bearing flanges. The two linear bearing flanges are fixed to the fixed support, and the two linear bearings pass through the two linear bearing flanges and slide along them respectively. The two ends of the support plate are fixedly connected to one end of the two linear bearings respectively, and the middle part of the support plate is connected to the output end of the lead screw assembly.

[0013] In some embodiments, the screwing assembly includes: a third motor, a motor bracket, and a screwing head; the motor bracket is fixedly connected to the output end of the linear assembly, the third motor is mounted on the motor bracket by a floating screw, so that the third motor has a floating amount in a plane perpendicular to the axial direction; the screwing head is fixedly connected to the output shaft of the third motor, and the end of the screwing head is provided with an interface shape that matches the interface of the component to be screwed.

[0014] In some embodiments, the third motor is an ultrasonic motor, which integrates a real-time torque measurement function for closed-loop monitoring of the torque during the twisting process.

[0015] To address the aforementioned technical problems, this application provides a gripping and tightening method applied to an end effector. The end effector includes a gripping mechanism, a linear assembly, and a tightening assembly. The gripping mechanism comprises multiple gripping claws distributed circumferentially, and the tightening assembly is located on the central axis of the multiple gripping claws. The method includes the following steps: The gripping claws of the gripping mechanism open; The gripping claw closes when it approaches the component to be tightened, thereby gripping the component to be tightened; The end effector does not require switching between the gripping mechanism and the screwing assembly. The linear assembly directly drives the screwing assembly to move axially, so that the screwing head of the screwing assembly engages with the interface of the element to be screwed. The screwing assembly rotates in the first direction to perform a tightening operation on the element to be tightened; The linear component drives the screwing component to move in the opposite direction, causing the screwing head to disengage from the element to be screwed, and the gripping claws open to release the element to be screwed.

[0016] To address the aforementioned technical problems, this application provides a gripping and unlocking method applied to an end effector. The end effector includes a gripping mechanism, a linear assembly, and a screwing assembly. The gripping mechanism comprises multiple gripping claws distributed circumferentially, and the screwing assembly is located on the central axis of the multiple gripping claws. The method includes the following steps: The gripping claws of the gripping mechanism open; The gripping claw closes when it approaches the component to be tightened, thereby gripping the component to be tightened; The end effector does not require switching between the gripping mechanism and the screwing assembly. The linear assembly directly drives the screwing assembly to move axially, so that the screwing head of the screwing assembly engages with the interface of the element to be screwed. The screwing assembly rotates in the second direction to loosen the element to be screwed; The linear component drives the screwing component to move in the opposite direction, causing the screwing head to disengage from the element to be screwed. The gripping claw remains closed, moves the element to be screwed to a designated position, and then opens to release it.

[0017] Compared with the prior art, this application has the following advantages: The end effector and its control method with gripping and twisting functions disclosed in this application, by coaxially nesting the gripping mechanism and the twisting component and rigidly integrating them on the same fixed support, allows the gripping claw to be arranged circumferentially and the twisting component to be located on the central axis. The two are highly overlapping in space rather than axially connected, eliminating the need for any tool switching mechanism or modular interface, saving the axial and radial space occupied by the switching mechanism. The overall structure is highly compact and can enter the narrow working space inside and around the satellite. At the same time, since the gripping mechanism and the twisting component are rigidly integrated and do not require switching, after the gripping claw grips the component to be twisted, the twisting component does not require any tool switching, mechanism reorganization or posture repositioning. The linear component directly drives the twisting component to feed axially to complete the introduction of the twisting head and the twisting operation. This fundamentally solves the core pain points of low operation efficiency, long docking time and high cost caused by frequent replacement of end effectors or switching of functional modules in the prior art. Attached Figure Description

[0018] The accompanying drawings are included to provide a further understanding of this application. They are incorporated into and constitute a part of this application. The drawings illustrate embodiments of this application and, together with this specification, serve to explain the principles of this application.

[0019] Figure 1 This is an exploded view of an end effector with gripping and twisting functions according to an embodiment of this application.

[0020] Figure 2 This is an overall schematic diagram of an end effector with gripping and twisting functions according to an embodiment of this application.

[0021] Figure 3 This is a schematic diagram of the gripping mechanism located on the lower side of the fixed support according to an embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the gripping mechanism located on the upper side of the fixed support according to an embodiment of this application.

[0023] Figure 5 This is a schematic diagram of the structure of a multifaceted columnar rack according to an embodiment of this application.

[0024] Figure 6 This is a schematic diagram of the structure of a linear assembly and a screw assembly according to an embodiment of this application.

[0025] Figure 7 This is a schematic diagram of the gripping mechanism opening according to an embodiment of this application.

[0026] Figure 8 This is a schematic diagram of a screwing assembly being introduced into the element to be screwed according to an embodiment of this application.

[0027] Figure 9 This is a flowchart of a gripping and tightening method of an end effector according to an embodiment of this application.

[0028] Figure 10 This is a flowchart of a grabbing and unlocking method of an end effector according to an embodiment of this application. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0030] This application provides an end effector with gripping and twisting functions and its control method, in order to overcome the technical defects of the prior art where the end effector has a single function and requires tool replacement, resulting in low work efficiency, and has a complex structure and large size that cannot be adapted to the narrow working space of satellites.

[0031] like Figure 1 and Figure 2 As shown, the present invention provides an end effector with gripping and twisting functions, including a gripping mechanism 1, a linear assembly 2, a twisting assembly 3, and a fixed support 13. The fixed support 13 is used to support all functional components of the end effector. The gripping mechanism 1 includes multiple gripping claws 18 distributed circumferentially. The twisting assembly 3 is located on the central axis of the multiple gripping claws 18. The linear assembly 2 is used to drive the twisting assembly 3 to move axially.

[0032] In this process, after the gripper 18 grips the element to be tightened 4, the end effector does not need to switch between the gripping mechanism 1 and the tightening assembly 3. The linear assembly 2 directly drives the tightening assembly 3 to move axially so that the tightening head 32 of the tightening assembly 3 engages with the interface of the element to be tightened 4, thereby tightening the element to be tightened 4.

[0033] In some embodiments, such as Figure 1As shown, the end effector with gripping and twisting functions also includes an adapter tube 10. One end of the adapter tube 10 is mounted on the upper side of the fixed support 13, and the other end is used to connect to the end flange of the robotic arm, so as to realize the rigid connection between the robotic arm and the entire end effector.

[0034] like Figure 3 and Figure 4 As shown, the gripping mechanism 1 includes a first motor 14, multiple sets of gears 15, a multifaceted cylindrical rack 16, and multiple sets of gear shafts 17, as well as multiple gripping claws 18 distributed circumferentially. The multiple sets of gear shafts 17 are mounted on bearing seats 19 via bearings, and the bearing seats 19 are fixed on fixed supports 13. The multiple sets of gears 15 are respectively mounted on the multiple sets of gear shafts 17, and the multiple sets of gears 15 mesh with the multifaceted cylindrical racks 16. The multiple gripping claws 18 are respectively fixedly mounted on the multiple sets of gear shafts 17.

[0035] In this embodiment, the multiple gripping claws 18 are three L-shaped hooks, evenly distributed along the circumference. Correspondingly, there are three sets of gear shafts 17 and gears 15. The three gripping claws 18 are respectively fixedly mounted on three sets of gear shafts 17, and each set of gears 15 is mounted on one set of gear shafts 17. It should be noted that this application is not limited to three gripping claws. In other embodiments, two, four, or more gripping claws can be set according to specific task requirements, and the number of gear sets can be adjusted accordingly.

[0036] The multifaceted columnar rack 16 has multiple sides, and the sides that mesh with the gears 15 are machined with meshing teeth. Each set of gears 15 meshes with the meshing teeth on one side of the multifaceted columnar rack 16. For example... Figure 5 As shown, in the embodiment, the multifaceted columnar rack 16 is a triangular prism rack, with meshing teeth machined on all three sides. The three sets of gears mesh one-to-one with the meshing teeth on the three sides of the triangular prism rack.

[0037] The first motor 14 is fixedly connected to the fixed support 13. The output shaft of the first motor 14 is connected to one of the gear shafts 17 via a coupling. When the first motor 14 rotates, it drives the gear 15 directly connected to the motor to rotate. Through gear and rack meshing, the gear 15 drives the multifaceted columnar rack 16 to move axially. The multifaceted columnar rack 16 then transmits power synchronously to the other two gears 15. The three gears 15 rotate synchronously, driving the three gripping claws 18 to open or close synchronously, thus completing the gripping or releasing of the component to be tightened.

[0038] Since the multi-faceted columnar rack 16 is arranged axially in the central area of ​​the end effector, it does not occupy radial space. Compared with the traditional "central large gear and multiple independent racks" scheme, the radial dimension is significantly reduced and the number of parts is greatly reduced, leaving a key space channel for the arrangement of the screwing assembly on the central axis.

[0039] like Figure 4As shown, in this embodiment, the gripping mechanism 1 further includes a guide rail slider support 11 and a guide rail slider 12. The guide rail slider support 11 is fixedly installed on the upper side of the fixed support 13, the guide rail slider 12 is installed on the guide rail slider support 11, and the multifaceted columnar rack 16 is fixed on the guide rail slider 12 to achieve linear guidance of the multifaceted columnar rack 16 during axial movement.

[0040] like Figure 6 As shown, the linear assembly 2 includes a support plate 20, a linear bearing 21, a second motor 23, a second motor bracket 24, and a lead screw assembly. The lead screw assembly includes a lead screw mounting base 25, a lead screw 26, and a lead screw nut 27. The lead screw mounting base 25 is fixed to the fixed support 13, the lead screw 26 is installed in the lead screw mounting base 25, and the lead screw nut 27 is fitted onto the lead screw 26.

[0041] In this embodiment, there are two linear bearings 21. The linear assembly 2 also includes two linear bearing flanges 22, which are circumferentially distributed and fixed on the fixed support 13. The two linear bearings 21 pass through the two linear bearing flanges 22 respectively and can slide up and down along them. One end of the linear bearing 21 is fixedly connected to the screwing assembly 3, and the other end is fixedly connected to the support plate 20.

[0042] The two ends of the support plate 20 are fixedly connected to one end of each of the two linear bearings 21, and the middle part of the support plate 20 is fixedly connected to the lead screw nut 27. Since the support plate 20 is simultaneously connected to both linear bearings 21, it forms a circumferential constraint on the lead screw nut 27, preventing the lead screw nut 27 from rotating when the lead screw 26 rotates, and instead allowing it to move axially. The support plate of this application connects two linear bearings and one lead screw nut simultaneously, achieving rigid linkage through the same support plate, forming a symmetrical force-bearing configuration of "guided at both ends, driven in the middle." This configuration ensures that the support plate and the screwing assembly fixedly connected to it experience balanced forces during axial movement, effectively avoiding the overturning moment and off-center load problems easily generated by unilateral drive. In a weightless or microgravity environment, although the influence of gravity is eliminated, the inertial force and operational reaction force generated by the movement of the robotic arm still exist. The double-sided symmetrical guide structure can resist the radial reaction force and overturning moment from the screwing operation, ensuring the coaxiality of the screwing head and the interface of the component to be screwed (such as a screw), and improving the reliability of the screwing operation.

[0043] The second motor 23 is connected to the lead screw 26 for transmission. When the second motor 23 rotates, it drives the lead screw 26 to rotate. The lead screw 26 and the lead screw nut 27 form a lead screw nut pair, which converts the rotational motion into linear motion. The lead screw nut 27 drives the support plate 20 and the two linear bearings 21 to slide axially, thereby driving the screwing assembly 3 to move axially, so as to move the screwing head 32 closer to or away from the element to be screwed.

[0044] The linear assembly of this application is arranged compactly along the axial direction behind the central axis of the gripping mechanism, without increasing the radial dimension of the end effector. Together with the coaxially nested gripping mechanism and screwing assembly, it forms a highly compact overall layout.

[0045] like Figure 6 As shown, the tightening assembly 3 includes a third motor bracket 30, a third motor 31, and a tightening head 32. The third motor bracket 30 is fixed to one end of the linear bearing 21 and moves up and down with the linear bearing 21. The third motor 31 is connected to the third motor bracket 30. The tightening head 32 is fixedly connected to the output shaft of the third motor 31. The end of the tightening head 32 has an interface shape that matches the interface of the component to be tightened (such as the cross slot, internal hexagonal hole, external hexagonal hole, etc. of a screw), ensuring that the component to be tightened can be accurately inserted. When the linear assembly drives the tightening assembly 3 to move axially, so that the tightening head 32 is inserted into the interface of the component to be tightened, the third motor 31 starts to rotate, transmitting power to the tightening head 32 fixedly connected to its output shaft. The tightening head 32 drives the component to be tightened (such as a screw) to rotate around its own axis, realizing the tightening or loosening operation of the component to be tightened.

[0046] In some embodiments, the third motor 31 is connected to the third motor bracket 30 via a floating screw, allowing the third motor 31 to float in a plane perpendicular to the axial direction. For example, the diameter of the floating screw is smaller than the diameter of the corresponding mounting hole on the third motor bracket 30, forming an annular gap between them, allowing the third motor 31 to slide within a small range relative to the third motor bracket 30 in the plane. This floating amount provides positional adaptability for the screwing head 32. When there is a small positional deviation after the gripper grasps the component to be screwed, the third motor 31 and the screwing head 32 can adaptively move in a plane perpendicular to the axial direction to compensate for the gripping positioning error, allowing the screwing head 32 to be smoothly inserted into the interface of the component to be screwed without visual guidance or additional degree-of-freedom adjustment. This structure eliminates the need for industrial vision guidance and multi-degree-of-freedom adjustment platforms, further reducing the size and weight of the end effector, while avoiding the risk of vision system failure in the poor lighting conditions inside the satellite cabin.

[0047] In some embodiments, the third motor 31 is an ultrasonic motor. Ultrasonic motors are characterized by their small size and high torque density, making them particularly suitable for the lightweight requirements of on-orbit aerospace operations. Ultrasonic motors integrate real-time torque measurement capabilities, enabling closed-loop monitoring of the torque during the tightening process, precisely controlling the tightening torque of screws in aerospace equipment, and preventing damage to precision equipment on board.

[0048] In some embodiments, the output shaft of the third motor 31 is in the form of a flange, and the screwing head 32 is directly fixed to the flange-type output shaft. The flange connection is an axial end face connection, which occupies almost no additional axial space compared to the traditional coupling connection method. The screwing head and the motor output shaft are directly connected in the axial direction, eliminating the length and installation clearance of the coupling, effectively compressing the overall axial dimension of the screwing assembly, allowing the end effector to enter the narrower working area inside the satellite.

[0049] In some embodiments, the first motor 14 of the gripping mechanism is a power-off self-locking motor, which can automatically lock the position of multiple gripping claws in the power-off state to prevent the gripped screws from falling off.

[0050] In some embodiments, the lead screw 26 of the linear assembly is a trapezoidal lead screw. The trapezoidal lead screw has a mechanical self-locking characteristic, which can automatically lock the axial position of the linear bearing 21 and the screwing assembly when the second motor 23 is de-energized, preventing the screwing head 32 from shifting and impacting the satellite's precision equipment.

[0051] In some embodiments, the aforementioned power-off self-locking motor and trapezoidal lead screw together constitute a dual self-locking position holding structure. On one hand, the first motor 14 of the gripping mechanism is a power-off self-locking motor, which can automatically lock the position of multiple gripping claws in the power-off state to prevent the gripped screw from falling off. On the other hand, the lead screw 26 of the linear assembly is a trapezoidal lead screw. The trapezoidal lead screw has mechanical self-locking characteristics, and can automatically lock the axial position of the linear bearing 21 and the screwing assembly when the second motor 23 is powered off, preventing the screwing head 32 from shifting and impacting the satellite's precision equipment. The dual self-locking design ensures that the end effector can maintain reliable gripping of the component to be screwed by the gripping claws and keep the axial position of the screwing assembly unchanged under any power-off failure caused by space irradiation, single-particle flip, etc., significantly reducing the risk of failure during on-orbit operation, and is particularly suitable for satellite on-orbit servicing missions with extremely high reliability requirements.

[0052] This application utilizes a coaxial nested integrated architecture to rigidly integrate the gripping mechanism and the turning assembly onto the same fixed support. The gripping claw is arranged circumferentially, while the turning assembly is located on the central axis. The two are highly overlapping in space rather than axially connected, eliminating the need for any tool switching mechanism, modular interface, or quick-change connector, thus saving the axial and radial space occupied by the switching mechanism. At the same time, a multi-faceted columnar rack is used as the transmission structure, achieving synchronous transmission of multiple gears with a single rack, significantly reducing the radial dimension and leaving a critical channel for the arrangement of the turning assembly on the central axis. The ultrasonic motor is installed with floating screws, enabling adaptive insertion of the turning head without visual guidance and a multi-degree-of-freedom adjustment platform, saving the space and weight occupied by the vision camera and adjustment mechanism. The trapezoidal lead screw and linear bearing are compactly arranged axially, with the lead screw itself also serving as a self-locking element, eliminating the need for an additional brake mechanism. The above integrated design allows the maximum radial dimension of the end effector in the retracted state to be controlled within the closed contour of the gripper. The overall volume and weight are significantly smaller than the existing modular switching scheme, enabling it to smoothly enter the narrow working space inside the satellite and around components such as the solar array drive mechanism to complete gripping and twisting operations.

[0053] Meanwhile, since the gripping mechanism and the screwing component are rigidly integrated and coaxially nested, after the gripping claw completes the gripping and positioning of the component to be screwed, the screwing component does not require any tool switching, mechanism reorganization or position repositioning. The linear component directly drives the screwing component to feed along the axial direction to complete the screwing head introduction and screwing operation, which fundamentally solves the core pain points of high docking cost and long operation time caused by frequent replacement of end effectors or switching of functional modules in the existing technology.

[0054] The following further explains the working method of this end effector. This method includes a gripping tightening method and a gripping unlocking method, corresponding to the installation and removal of components to be tightened in on-orbit maintenance tasks, respectively. The common logic of both methods is as follows: the gripping mechanism first grips and positions the component to be tightened. Then, without any tool switching or position repositioning, the linear component directly drives the screwing component to move axially, aligning the screwing head with the interface of the component to be tightened. Finally, the screwing component performs the tightening or loosening operation. The difference between the two methods lies in the rotation direction of the screwing component and the state of the gripping claws after the operation is completed. After tightening, the gripping claws open directly to release the component; after loosening, the gripping claws remain closed, and the loosened component is moved to a designated storage location before being released.

[0055] The following combination Figure 7 , Figure 8 , Figure 9 and Figure 10 The implementation steps of the two working methods described above are described in detail. For example... Figure 9 As shown, the gripping and tightening methods include: Step S101: The multiple gripping claws of the gripping mechanism open.

[0056] like Figure 7 As shown, when the robotic arm receives the gripping and tightening task command, the robotic arm drives the end effector with gripping and tightening functions to start moving. The first motor starts to rotate forward, driving the gear directly connected to the first motor to rotate. Through the meshing of the gear and rack, the multi-faceted columnar rack then drives the power to transmit to the other two sets of gears, realizing the opening of the L-shaped hook.

[0057] Step S102: The gripping claw closes when it approaches the component to be tightened, thus gripping the component to be tightened.

[0058] The robotic arm drives the end effector, which has gripping and twisting functions, to approach the screw to be tightened. When it gets close to the screw to be tightened at a certain distance, the first motor starts to reverse, and the L-shaped hook closes, completing the gripping of the screw to be tightened.

[0059] In some embodiments, after the L-shaped claw picks up the screw to be tightened, it moves the screw to a designated installation position (e.g., inside the mounting hole).

[0060] Step S103: The end effector does not need to switch between the gripping mechanism and the screwing assembly. The linear assembly directly drives the screwing assembly to move axially, so that the screwing head of the screwing assembly engages with the interface of the component to be screwed.

[0061] It should be noted that during the gripping process, the linear component is in a retracted state to avoid interference between the screwdriver head and the screw to be tightened. For example... Figure 8 As shown, after successfully gripping the screw to be tightened, the linear assembly begins to move. The second motor rotates, driving the trapezoidal lead screw to rotate, converting the rotational motion into linear motion. The linear assembly then drives the tightening assembly downwards, guiding the tightening head into the interface of the screw to be tightened. It should be noted that during the guiding process, the tightening assembly has a certain amount of planar float, allowing for a smooth guiding process.

[0062] Step S104: The screwing assembly rotates in the first direction to perform a tightening operation on the element to be tightened.

[0063] Once the import is complete, the second motor stops, and the self-locking characteristic of the trapezoidal screw keeps the screw-tightening assembly in the correct position. Optionally, the gripping claws slightly loosen to reduce the radial clamping force, ensuring that the screw to be tightened can rotate circumferentially. The third motor then starts rotating forward, driving the screw-tightening head to rotate and tighten the screw. It should be noted that when the third motor is an ultrasonic motor, it has torque measurement capabilities, allowing for real-time monitoring of the tightening torque and improving reliability.

[0064] Step S105: The linear assembly drives the screwing assembly to move in the opposite direction, causing the screwing head to disengage from the component to be screwed, and the gripping claws open to release the component to be screwed.

[0065] The first motor starts rotating forward, causing the L-shaped claw to open. The linear assembly drives the screw-tightening assembly to move upward, and the screw-tightening head disengages from the screw to be tightened. At this point, all gripping and tightening actions are completed, and the robotic arm can be withdrawn.

[0066] like Figure 10 As shown, the methods for grabbing and unlocking include: Step S201: The multiple gripping claws of the gripping mechanism open.

[0067] When the robotic arm receives the gripping and unlocking task command, the robotic arm drives the end effector with gripping and twisting functions to start moving. The first motor starts to rotate forward, driving the gear directly connected to the first motor to rotate. Through the meshing of the gear and rack, the multi-faceted columnar rack then drives the power to transmit to the other two sets of gears, realizing the opening of the L-shaped claw.

[0068] Step S202: The gripping claw closes when it approaches the component to be tightened, thus gripping the component to be tightened.

[0069] The robotic arm drives the end effector, which has gripping and twisting functions, to approach the screw to be tightened. When it gets close to the screw at a certain distance, the first motor starts to reverse, and the L-shaped hook closes, completing the gripping of the screw to be tightened.

[0070] Step S203: The end effector does not need to switch between the gripping mechanism and the screwing assembly. The linear assembly directly drives the screwing assembly to move axially, so that the screwing head of the screwing assembly engages with the interface of the component to be screwed.

[0071] It should be noted that during the gripping process, the linear assembly is in a retracted state to avoid interference between the screw head and the screw to be tightened. After gripping the screw, the linear assembly begins to move, the second motor rotates, driving the trapezoidal lead screw to rotate, converting the rotational motion into linear motion. The linear assembly then moves the screw-tightening assembly downwards, guiding the screw head into the interface of the screw. It is worth noting that during the guiding process, the screw-tightening assembly has a certain amount of planar float, which allows for a smooth guiding process.

[0072] Step S204: The screwing assembly rotates in the second direction to loosen the component to be screwed.

[0073] Once the import is complete, the second motor stops, and the self-locking characteristic of the trapezoidal screw keeps the tightening assembly in the corresponding position. Optionally, the gripping claws slightly loosen to reduce the radial clamping force, ensuring that the screw to be tightened can rotate circumferentially. The third motor then reverses, driving the tightening head to rotate and loosening the screw. It should be noted that when the third motor is an ultrasonic motor, it has torque measurement capabilities, allowing for real-time monitoring of the tightening torque and improving reliability.

[0074] Step S205: The linear assembly drives the screwing assembly to move in the opposite direction, causing the screwing head to disengage from the component to be screwed. The gripping claw remains closed and moves the component to be screwed to the designated position before opening and releasing it.

[0075] In some embodiments, after the screwing head disengages from the component to be screwed, the gripping claw increases its closing force while maintaining a closed state, moves the component to be screwed to a designated position, and then opens and releases.

[0076] In this application, the "grab-and-tighten" operation of the gripping claw and the screwing head is spatially independent and functionally coordinated. The gripping claw acts on the radial outer periphery of the component to be tightened. The continuous radial clamping force applied by the gripping claw provides sufficient friction to ensure that the component to be tightened will not loosen or fall off during the gripping process, thus moving the component to be tightened (the screw to be tightened) to the designated position (inside the mounting hole). When tightening is required, the screwing head acts on the axial end face interface of the component to be tightened and begins to tighten. At the same time, the gripping claw slightly loosens, reducing the radial clamping force, ensuring that the screw to be tightened can rotate circumferentially, realizing the tightening of the threaded pair. From a functional perspective, the presence of the gripping claw in the tightening process is not an obstacle, but rather provides necessary reaction force support for the tightening operation, ensuring that the screw is always coaxial with the mounting hole under tightening conditions, so that the loosening or tightening operation can be completed efficiently.

[0077] Flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, various steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from these processes.

[0078] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

[0080] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0081] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. An end effector with gripping and twisting functions, characterized in that, include: A fixed support, and a gripping mechanism, a linear assembly, and a screwing assembly disposed on the fixed support; The gripping mechanism includes multiple gripping claws distributed circumferentially, the twisting assembly is located on the central axis of the multiple gripping claws, and the linear assembly is used to drive the twisting assembly to move axially. In this configuration, after the gripper grasps the component to be tightened, the end effector does not need to switch between the gripping mechanism and the tightening assembly. The linear assembly directly drives the tightening assembly to move axially, so that the tightening head of the tightening assembly engages with the interface of the component to be tightened, thereby tightening the component.

2. The end effector as described in claim 1, characterized in that, The grasping mechanism also includes: The first motor, the multi-faceted cylindrical rack, and the multiple sets of gear shafts and multiple sets of gears; Multiple sets of gear shafts are rotatably supported on the fixed support, multiple sets of gears are respectively mounted on multiple sets of gear shafts, multiple sets of gears mesh with the multifaceted columnar rack, and multiple gripping claws are respectively fixedly mounted on multiple sets of gear shafts; The first motor drives one set of gears to rotate, and transmits power synchronously to the other sets of gears through the multifaceted columnar rack, so as to drive the multiple gripping claws to open or close.

3. The end effector as described in claim 2, characterized in that, The multifaceted columnar rack has multiple sides, and the sides of the multifaceted columnar rack that mesh with the gears are machined with meshing teeth. Each set of gears meshes with the meshing teeth on one side of the multifaceted columnar rack.

4. The end effector as described in claim 2, characterized in that, The first motor is a power-off self-locking motor.

5. The end effector as described in claim 1, characterized in that, The linear component includes: Second motor, lead screw assembly, support plate and linear bearing; The lead screw assembly is mounted on the fixed support, the support plate is fixedly connected to the output end of the lead screw assembly and one end of the linear bearing, and the other end of the linear bearing is fixedly connected to the screwing assembly. The second motor drives the lead screw assembly to move, causing the support plate and the linear bearing to slide axially, thereby causing the screwing assembly to move axially.

6. The end effector as described in claim 5, characterized in that, The lead screw assembly includes a lead screw, a lead screw nut, and a lead screw fixing seat. The lead screw is a trapezoidal lead screw with mechanical self-locking characteristics, which automatically locks the axial position of the linear bearing and the screwing assembly when the second motor is de-energized.

7. The end effector as described in claim 5, characterized in that, The linear bearing is two, and the linear assembly also includes two linear bearing flanges. The two linear bearing flanges are fixed to the fixed support, and the two linear bearings pass through the two linear bearing flanges respectively and slide along them. The two ends of the support plate are respectively fixedly connected to one end of the two linear bearings, and the middle part of the support plate is connected to the output end of the lead screw assembly.

8. The end effector as claimed in claim 1, characterized in that, The screwing assembly includes: Third motor, motor bracket and screw head; The motor bracket is fixedly connected to the output end of the linear assembly, and the third motor is mounted on the motor bracket by floating screws, so that the third motor has a floating amount in a plane perpendicular to the axial direction. The screwing head is fixedly connected to the output shaft of the third motor, and the end of the screwing head has an interface shape that matches the interface of the component to be screwed.

9. The end effector as claimed in claim 8, characterized in that, The third motor is an ultrasonic motor, which integrates a real-time torque measurement function for closed-loop monitoring of the torque during the twisting process.

10. A gripping and tightening method applied to an end effector, the end effector comprising a gripping mechanism, a linear assembly, and a tightening assembly, the gripping mechanism comprising a plurality of gripping claws distributed circumferentially, the tightening assembly being located on the central axis of the plurality of gripping claws, characterized in that, Includes the following steps: The gripping claws of the gripping mechanism open; The gripping claw closes when it approaches the component to be tightened, thereby gripping the component to be tightened; The end effector does not require switching between the gripping mechanism and the screwing assembly. The linear assembly directly drives the screwing assembly to move axially, so that the screwing head of the screwing assembly engages with the interface of the element to be screwed. The screwing assembly rotates in the first direction to perform a tightening operation on the element to be tightened; The linear component drives the screwing component to move in the opposite direction, causing the screwing head to disengage from the element to be screwed, and the gripping claws open to release the element to be screwed.

11. A gripping and unlocking method applied to an end effector, the end effector comprising a gripping mechanism, a linear assembly, and a screwing assembly, the gripping mechanism comprising a plurality of gripping claws distributed circumferentially, the screwing assembly being located on the central axis of the plurality of gripping claws, characterized in that, Includes the following steps: The gripping claws of the gripping mechanism open; The gripping claw closes when it approaches the component to be tightened, thereby gripping the component to be tightened; The end effector does not require switching between the gripping mechanism and the screwing assembly. The linear assembly directly drives the screwing assembly to move axially, so that the screwing head of the screwing assembly engages with the interface of the element to be screwed. The screwing assembly rotates in the second direction to loosen the element to be screwed; The linear component drives the screwing component to move in the opposite direction, causing the screwing head to disengage from the element to be screwed. The gripping claw remains closed, moves the element to be screwed to a designated position, and then opens to release it.

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