An active telescopic space manipulator joint for on-orbit assembly tasks

Abstract

An active telescopic space manipulator joint for on-orbit assembly tasks, which relates to the field of space robot technology. The arm rod unit includes a small arm rod, a middle arm rod and a large arm rod that are nested step by step, and the movement along the axial direction is restricted by the cooperation of the guiding boss and the guiding groove; the electromechanical interface unit includes a small arm rod interface and a large arm rod interface; the wire routing unit is built in the arm rod unit for the cable connection from the large arm rod interface to the small arm rod interface; the anti-extension unit is used to restrain the premature extension of the middle arm rod; the anti-retraction unit is used to prevent the fully extended small arm rod from retracting; the transmission system uses a rotary joint to connect the main transmission lead screw and cooperate with the small arm rod roller nut assembly and the middle arm rod roller nut assembly to control the telescopic movement of the arm rod unit. It has the ability of active telescoping, and through the anti-extension unit and the anti-retraction unit, the sequential extension, locking and unlocking of each section of the arm rod are completed. The built-in cable laying mechanism is adopted to reduce the system complexity and mass and improve the overall stability.

Description

Technical Field

[0001] The present invention relates to the technical field of space robots, and specifically to an active telescopic space robotic arm joint for on-orbit assembly tasks. Background Art

[0002] Existing space robotic arms still mainly adopt a fixed-length design, or in a few cases, a passive telescopic method, that is, relying on the movement of other joints to stretch the arm to a preset position. For a single telescopic joint, it cannot independently adjust its length. The telescopic ratio of such passive telescopic designs is usually small, and only single-segment telescoping can be achieved, occupying a large space and being difficult to adapt to the limited cargo bay space of a launch vehicle. Therefore, in practical applications, such robotic arms often use an external hanging method to go into space, such as the next-generation Canadian robotic arm (Canadarm3). However, the external hanging scheme may have an adverse impact on the reliability and service life of the robotic arm. In addition, in task scenarios with a large operating range requirement, the limitations of the passive telescopic method are particularly obvious. On the other hand, currently, space robotic arm joints that can be repeatedly telescoped usually require an independent locking motor and a corresponding locking mechanism for each telescopic segment to achieve locking and unlocking. This design results in a relatively complex joint structure, a large mass, and relatively low reliability, which is not conducive to reducing the overall mass of the spacecraft and increases the launch cost of the rocket. In addition, the telescopic joints of space robotic arms are usually connected end to end with other joints or operating tools, and signal and power cables need to be laid. Existing solutions mainly adopt an external cable method to simplify the internal wiring design. However, the external cables lack the protection and restraint of the rod shell and are vulnerable to impacts or cuts by space debris in the space environment, posing risks such as breakage and entanglement, which may affect the safety and reliability of the telescopic joint and even the entire space robotic arm system.

[0003] In summary, when facing on-orbit assembly tasks with long distances, complex structures, and limited payloads, existing space robotic arms are often restricted by factors such as insufficient independence of the telescopic mechanism, complex locking mechanism, limited cable layout, and large overall mass, resulting in reduced system reliability and limited task execution efficiency. In particular, the robotic arm joints with existing passive telescopic designs cannot independently adjust their lengths, rely on the movement of external joints for telescoping, and mostly require an independent locking motor and locking mechanism for each telescopic segment, resulting in a complex structure and increased mass. In addition, existing cable layout methods mostly adopt an external scheme, lacking effective restraint and protection, and are vulnerable to breakage caused by impacts from space debris or entanglement with other cables outside the cabin in the space environment, affecting the safety and stability of the telescopic joint and even the entire robotic arm system. Therefore, how to reduce the system complexity and improve the overall reliability as much as possible while ensuring that the robotic arm has an active telescopic function, and optimize the cable layout method to achieve reliable internal wiring of the cables has become an urgent problem for space robotic arms at the present stage. Summary of the invention

[0004] In order to address the shortcomings of the background technology, the present invention provides an active telescopic space robot arm joint for on-orbit assembly tasks, which has active telescopic capabilities, and completes the sequential extension, locking and unlocking of each section of the arm through a stop unit and a non-return unit, and adopts a built-in cable laying mechanism to reduce the complexity and quality of the system and improve the overall stability.

[0005] To achieve the above-mentioned object, the present invention adopts the following technical scheme: an active telescopic space robot arm joint for on-track assembly tasks, comprising an arm unit, an electromechanical interface unit, a routing unit, a stop unit, a non-return unit and a transmission system;

[0006] The arm unit comprises a small arm, a middle arm and a large arm which are nested step by step from the inside to the outside. The outer walls of the small arm and the middle arm are respectively provided with guide bosses, and the inner walls of the middle arm and the large arm are correspondingly provided with guide grooves. The small arm and the middle arm can only move along the axial direction through the cooperation of the guide bosses and the guide grooves.

[0007] The electromechanical interface unit includes a small arm interface installed on the top of the small arm and a large arm interface installed on the bottom of the large arm;

[0008] The wiring unit is built into the arm unit and is used for connecting the cables from the large arm interface to the small arm interface;

[0009] The stop unit is composed of two sets of mechanisms arranged opposite to each other, each set of mechanisms includes a stop housing, a stop trigger element, a stop piece and a stop column, the stop housing is mounted on the top of the middle arm, the stop trigger element is mounted on the bottom side of the outer wall of the small arm, a tooth socket structure is arranged on the top of the outer side of the stop trigger element, a beak-shaped structure is arranged on the head of the stop piece to match the tooth socket structure of the stop trigger element, a hook structure is arranged below the tail of the stop piece, the stop column is mounted on the top side of the outer wall of the large arm and extends upward and bends inward to set a hook structure, the stop piece is hingedly mounted in the stop housing and provides torque to the stop column by setting a torsion spring, so that the hook structures of the two fit together to restrain the middle arm from extending prematurely;

[0010] The check unit consists of two sets of mechanisms arranged oppositely. Each set of mechanisms includes a check housing, a check auxiliary element, a check piece, a check piece sliding pin, and a check guiding column. The check housing is installed at the top of the middle arm rod, the check auxiliary element is installed at the bottom side of the outer wall of the small arm rod, and an obtuse-angle cutting groove structure is machined at the bottom edge of the check auxiliary element. The check piece sliding pin is connected to the mounting hole at the tail of the check piece. The check guiding column is installed at the top side of the outer wall of the large arm rod and extends upward with an inclined slot for insertion and mating with the check piece sliding pin. The check piece is hinged and installed in the check housing and provides torque towards the check auxiliary element by setting a torsion spring. After the check piece sliding pin disengages from the inclined slot, the check piece supports the bottom edge of the check auxiliary element to prevent the fully extended small arm rod from retracting;

[0011] The transmission system includes a rotary joint, a main transmission lead screw, a small arm rod roller nut assembly, and a middle arm rod roller nut assembly. The rotary joint is coaxially fixed at the inner bottom of the large arm rod and connected to the main transmission lead screw. The main transmission lead screw is divided into a threaded section and a cylindrical section from top to bottom. The small arm rod roller nut assembly and the middle arm rod roller nut assembly are respectively coaxially fixed at the inner bottom of the small arm rod and the middle arm rod. In the initial contracted state, the small arm rod roller nut assembly meshes with the threaded section, and the middle arm rod roller nut assembly is located on the cylindrical section.

[0012] Furthermore, the wire routing unit is divided into two types: a fully extended mode wire routing unit and a segmented extended mode wire routing unit;

[0013] For the fully extended mode wire routing unit, wire grooves are machined on the inner sides of the guiding bosses of the small arm rod, the middle arm rod, and the large arm rod. At the same time, wire holes are machined at the bottom sides of the side walls of the small arm rod and the middle arm rod. Electric connector groups are respectively installed at the bottom of the outer wall of the small arm rod, the top of the inner wall of the large arm rod, and the top and bottom of the inner and outer walls of the middle arm rod. When the arm rod unit is fully extended, the electric connector groups at the bottom of the outer wall of the small arm rod and the top of the inner wall of the middle arm rod are docked and matched, and the electric connector groups at the bottom of the outer wall of the middle arm rod and the top of the inner wall of the large arm rod are docked and matched. The electric connector group at the bottom of the outer wall of the small arm rod is connected to the small arm rod interface, the two electric connector groups at the top and bottom of the inner and outer walls of the middle arm rod, and the electric connector group at the top of the inner wall of the large arm rod and the large arm rod interface are respectively connected by composite cable groups, and the composite cable groups are evenly arranged in the corresponding wire grooves;

[0014] For the segmented extension mode wire routing unit, limit bosses are respectively arranged at the bottom of the outer wall of the small arm rod, the top of the inner wall of the large arm rod, and the top of the inner wall and the bottom of the outer wall of the middle arm rod to prevent over-extension. Inter-segment transfer modules are respectively installed in the edge plane areas of the small arm rod roller nut assembly and the middle arm rod roller nut assembly. A small arm rod wall-attached cable is arranged inside the small arm rod to connect the small arm rod interface with the inter-segment transfer module on the small arm rod roller nut assembly. A middle arm rod spiral cable is arranged inside the middle arm rod to connect the two inter-segment transfer modules on the small arm rod roller nut assembly and the middle arm rod roller nut assembly. A large arm rod spiral cable is arranged inside the large arm rod to connect the large arm rod interface with the inter-segment transfer module on the middle arm rod roller nut assembly.

[0015] Further, the segmented extension mode wire routing unit is configured with a sensing system, and the sensing system includes two permanent magnets and two Hall sensors. The two permanent magnets are respectively adhered to the top of the inner walls of the middle arm rod and the large arm rod. The two Hall sensors are respectively installed in the edge plane areas of the small arm rod roller nut assembly and the middle arm rod roller nut assembly and are connected to the corresponding inter-segment transfer modules through connecting wires.

[0016] Further, both the small arm rod interface and the large arm rod interface have a genderless structure characteristic.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention has an active telescoping ability, can realize independent length adjustment of joints through the cooperation of the arm rod unit and the transmission system, and does not rely on a locking motor. Only through the mechanical structure form of the anti-extension unit and the anti-retraction unit, the sequential extension, locking, and unlocking of each section of the arm rod are completed, which helps to reduce the system mass. In addition, two simple and reliable cable layout methods suitable for the fully extended mode and the segmented extended mode are respectively designed for different task requirements. While reducing the system complexity, it ensures the reliable internal placement of the cables, reduces the launch cost, improves the overall stability and task execution efficiency, can be widely applied to long-distance on-orbit assembly tasks, and shows higher adaptability and reliability in complex task environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 are schematic diagrams of three typical states of the active telescoping space manipulator joint of the present invention;

[0019] Figure 2 is an exploded view of the anti-extension unit in the present invention;

[0020] Figure 3 is an exploded view of the anti-retraction unit in the present invention;

[0021] Figure 4 is a schematic diagram of the assembly and wire routing of the small arm rod section in the fully extended mode of the present invention;

[0022] Figure 5It is a schematic diagram of the assembly and wire routing of the middle arm rod section in the fully extended mode of the present invention;

[0023] Figure 6 It is a schematic diagram of the assembly and wire routing of the large arm rod section in the fully extended mode of the present invention;

[0024] Figure 7 It is a schematic diagram of the assembly and wire routing of the small arm rod section in the segmented extended mode of the present invention;

[0025] Figure 8 It is a schematic diagram of the assembly and wire routing of the middle arm rod section in the segmented extended mode of the present invention;

[0026] Figure 9 It is a schematic diagram of the assembly and wire routing of the large arm rod section in the segmented extended mode of the present invention;

[0027] Figure 10 It is a schematic diagram of the overall wire routing in the segmented extended mode of the present invention;

[0028] Figure 11 It is a definition diagram of the stop-out plane A-A and the check plane B-B in the specific implementation manner;

[0029] Figure 12 It is Figure 11 A schematic diagram of the action state of the stop-out plane A-A;

[0030] Figure 13 It is Figure 11 A schematic diagram of the action state of the check plane B-B.

[0031] In the figure: 1. Boom unit; 2. Electromechanical interface unit; 5. Anti-export unit; 6. Anti-backflow unit; 7. Transmission system; 101. Small boom; 102. Medium boom; 103. Large boom; 101-1. Full small boom; 101-2. Split small boom; 102-1. Full medium boom; 102-2. Split medium boom; 103-1. Full large boom; 103-2. Split large boom; 201. Small boom interface; 202. Large boom interface; 203. Small boom interface adapter; 204. Small boom interface adapter mounting screw; 205. Small boom interface mounting screw; 206. Large boom interface adapter; 207. Large boom interface adapter mounting screw; 208. Large boom interface mounting screw; 301-1. Electrical connector group one; 301-2. Electrical connector group two; 301-3. Electrical connector group three; 301-4. Electrical connector group four; 302. Electrical connector mounting screw; 303-1. Composite cable group one; 303-2. Composite cable group two; 303-3. Composite cable group three; 401. Inter-segment transfer module; 402. Inter-segment transfer module connection screw; 403. Small boom wall-attached cable; 404. Medium boom spiral cable; 405. Large boom spiral cable; 501. Anti-export housing mounting piece; 502. Anti-export housing mounting piece mounting screw; 503. Anti-export housing; 504. Anti-export housing mounting screw; 505. Anti-export trigger element; 506. Anti-export trigger element mounting screw; 507. Anti-export piece; 508. Anti-export column; 509. Anti-export column mounting screw; 510. Anti-export torsion spring; 511. Anti-export support shaft; 503-1. Inner top surface of anti-export housing; 503-2. Lip surface of anti-export housing; 505-1. Upper teeth of anti-export trigger element; 505-2. Lower teeth of anti-export trigger element; 507-1. Upper plane of hook-shaped structure of anti-export piece; 507-2. Upper beak of anti-export piece; 507-3. Lower beak of anti-export piece; 507-4. Upper surface of anti-export piece; 508-1. Lower plane of hook-shaped structure of anti-export column; 601. Anti-backflow housing mounting piece; 602. Anti-backflow housing mounting piece mounting screw; 603. Anti-backflow housing; 604. Anti-backflow housing mounting screw; 605. Anti-backflow auxiliary element; 606. Anti-backflow auxiliary element mounting screw; 607. Anti-backflow piece; 608. Anti-backflow piece mounting shaft; 609. Anti-backflow piece sliding pin; 610. Anti-backflow guiding column; 611. Anti-backflow guiding column mounting screw; 612. Anti-backflow torsion spring; 613. Anti-backflow torsion spring mounting shaft; 605-1. Support plane; 605-2. Transition slope; 607-1. Head of anti-backflow piece; 607-2. Upper slope; 610-1. Oblique notch; 701. Rotary joint; 702. Joint mounting screw; 703. Joint mounting piece; 704. Joint mounting piece connection screw; 705. Main transmission lead screw; 706. Lead screw mounting screw; 707. Joint lead screw adapter; 708. Joint lead screw adapter mounting screw; 709. Small boom roller nut assembly; 710. Medium boom roller nut assembly; 711. Nut assembly mounting screw;712. Joint mounting positioning pin; 801. Permanent magnet; 802. Hall sensor; 803. Hall sensor mounting screw; 804. Hall sensor connection wire. Detailed implementation mode

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] As Figures 1 to 13 shown, an active telescopic space manipulator joint for on-orbit assembly tasks includes an arm rod unit 1, an electromechanical interface unit 2, a wire routing unit, a stop-out unit 5, a check valve unit 6, and a transmission system 7.

[0034] The arm rod unit 1 includes three cylindrical rod segments, namely a small arm rod 101, a middle arm rod 102, and a large arm rod 103. As the base of the manipulator joint, it is used to carry other components while performing telescopic actions. Here, small, middle, and large refer to the inner diameter and length of the corresponding arm rods, so that the three rod segments are nested step by step from the inside out. Among them, the outer walls of the small arm rod 101 and the middle arm rod 102 are respectively processed with a plurality of guiding bosses evenly distributed along the circumferential direction from the top to the bottom, and are respectively matched with the guiding grooves opened at the corresponding positions on the inner walls of the middle arm rod 102 and the large arm rod 103 to limit the rotation of the small arm rod 101 and the middle arm rod 102 around the axis, so that they can only move along the axis direction.

[0035] The electromechanical interface unit 2 includes a small arm rod interface 201, a large arm rod interface 202, a small arm rod interface adapter 203, a small arm rod interface adapter mounting screw 204, a small arm rod interface mounting screw 205, a large arm rod interface adapter 206, a large arm rod interface adapter mounting screw 207, and a large arm rod interface mounting screw 208. Among them, the small arm rod interface adapter 203 is installed on the top of the small arm rod 101 through the small arm rod interface adapter mounting screw 204, and the small arm rod interface 201 is installed on the top of the small arm rod interface adapter 203 through the small arm rod interface mounting screw 205; the large arm rod interface adapter 206 is installed on the bottom of the large arm rod 103 through the large arm rod interface adapter mounting screw 207, and the large arm rod interface 202 is installed on the bottom of the large arm rod interface adapter 206 through the large arm rod interface mounting screw 208. The small arm rod interface 201 and the large arm rod interface 202 have the characteristics of genderless structure and large docking tolerance, can realize locking and unlocking, and at the same time take into account power supply and data transmission.

[0036] The anti-extension unit 5 includes an anti-extension housing mount 501, anti-extension housing mount screws 502, an anti-extension housing 503, anti-extension housing screws 504, an anti-extension trigger element 505, anti-extension trigger element screws 506, an anti-extension member 507, an anti-extension post 508, anti-extension post screws 509, an anti-extension torsion spring 510, and an anti-extension support shaft 511. Its function is to prevent the premature extension of the outer rod section, and it consists of two sets of identical mechanisms arranged oppositely. Among them, the anti-extension housing mount 501 is mounted on the top of the middle arm rod 102 through the anti-extension housing mount screws 502. The anti-extension housing 503 is mounted on the anti-extension housing mount 501 through the anti-extension housing screws 504. The anti-extension trigger element 505 is mounted on the bottom side of the outer wall of the small arm rod 101 through the anti-extension trigger element screws 506. An alveolar structure is provided on the top outside of the anti-extension trigger element 505. The anti-extension post 508 is mounted on the top side of the outer wall of the large arm rod 103 through the anti-extension post screws 509. The anti-extension post 508 extends upward and is bent inward to be provided with a hook-like structure. The anti-extension support shaft 511 is horizontally mounted between the shaft holes provided on both sides of the anti-extension housing 503. The anti-extension member 507 is mounted on the anti-extension support shaft 511 through the mounting hole above its tail. A hook-like structure is provided below the tail of the anti-extension member 507. Two cylindrical protrusions are integrally provided on both sides of the middle position of the anti-extension member 507. The head of the anti-extension member 507 is provided with a beak-like structure to cooperate with the alveolar structure of the anti-extension trigger element 505. The anti-extension torsion springs 510 are divided into two and symmetrically sleeved on the anti-extension support shaft 511 on both sides of the anti-extension member 507. The anti-extension torsion springs 510 are in a compressed state throughout the working process and always have a rotational tendency to return to the natural state. One end abuts against the inner top surface 503-1 of the anti-extension housing, and the other end abuts against the cylindrical protrusion of the anti-extension member 507. Under the pressure provided by the anti-extension torsion springs 510, the anti-extension member 507 always has a torque around the axis of the anti-extension support shaft 511 to turn towards the anti-extension post 508. In the anti-extension state (i.e., the state where the middle arm rod 102 does not extend), the upper plane 507-1 of the hook-like structure of the anti-extension member at the tail of the anti-extension member 507 fits together with the lower plane 508-1 of the hook-like structure at the top of the anti-extension post 508.

[0037] To more clearly show the action state of the anti-extension unit 5, in combination with Figure 11 as shown, define the anti-extension plane A-A as the plane exactly in the middle of the two anti-extension units 5. The anti-extension units 5 are symmetric about the anti-extension plane A-A. Cut along the anti-extension plane A-A, and take the left cross-section as an example to explain the principle. In combination with Figure 12As shown, the stop-out torsion spring 510 provides a clockwise torque to the stop-out member 507. The projection of the axis of the stop-out support shaft 511 on the lower plane 508-1 of the stop-out column hook-shaped structure is located within the joint area between the stop-out member 507 and the stop-out column 508. During the extension process of the entire arm unit 1, the boom 103 remains stationary. In the initial stage of the extension process of the forearm 101, due to the friction between the guiding boss on the outer wall of the forearm 101 and the guiding groove on the inner wall of the middle arm 102, the middle arm 102 is subjected to a force in the extension direction. This force is transmitted to the stop-out member 507 through the stop-out housing mounting member 501, the stop-out housing 503, and the stop-out support shaft 511 in sequence. The stop-out member 507 receives a reaction force from the stop-out column 508 in the direction opposite to the extension direction. Since the projection of the rotation axis of the stop-out member 507 is located within the joint area between the stop-out member 507 and the stop-out column 508, the stop-out member 507 does not rotate, that is, the middle arm 102 is indirectly restricted by the boom 103 and cannot extend prematurely. In the stop-out state, there is an overlapping area between the upper beak 507-2 of the stop-out member and the upper tooth 505-1 of the stop-out trigger element. As the forearm 101 extends, the stop-out trigger element 505 gradually approaches the stop-out member 507 until the upper tooth 505-1 of the stop-out trigger element contacts the upper beak 507-2 of the stop-out member, and the stop-out action begins to be released. As the forearm 101 continues to extend, the stop-out trigger element 505 pushes the stop-out member 507 to rotate counterclockwise. The upper plane 507-1 of the stop-out member hook-shaped structure disengages from the lower plane 508-1 of the stop-out column hook-shaped structure, and the upper beak 507-2 of the stop-out member gradually moves away from the stop-out trigger element 505. When the upper beak 507-2 of the stop-out member disengages from the upper tooth 505-1 of the stop-out trigger element, under the action of the stop-out torsion spring 510, the stop-out member 507 rotates clockwise in a very short time, so that the lower beak 507-3 of the stop-out member contacts the lower tooth 505-2 of the stop-out trigger element. The stop-out trigger element 505 continues to push the stop-out member 507 to rotate counterclockwise until the upper surface 507-4 of the stop-out member contacts the lip surface 503-2 of the stop-out housing, and the stop-out unit 5 completely releases the stop-out state. At this time, there is no overlapping area between the upper plane 507-1 of the stop-out member hook-shaped structure and the lower plane 508-1 of the stop-out column hook-shaped structure. After that, the force in the extension direction received by the forearm 101 is transmitted to the middle arm 102 through the stop-out member 507, the stop-out housing 503, and the stop-out housing mounting member 501. The forearm 101 drives the middle arm 102 to extend a certain distance, and the check unit 6 starts to perform the check action.

[0038] The check unit 6 includes a check housing mount 601, a check housing mount screw 602, a check housing 603, a check housing screw 604, a check auxiliary element 605, a check auxiliary element screw 606, a check member 607, a check member mounting shaft 608, a check member sliding pin 609, a check guide post 610, a check guide post screw 611, a check torsion spring 612, and a check torsion spring mounting shaft 613. Its function is to firmly hold the small arm rod 101 when it is fully extended to prevent it from retracting. It is also composed of two sets of identical mechanisms arranged oppositely and starts to perform the check action after the check-out state is completely released. Among them, the check housing mount 601 is mounted on the top of the middle arm rod 102 through the check housing mount screw 602, the check housing 603 is mounted on the check housing mount 601 through the check housing screw 604, the check auxiliary element 605 is mounted on the bottom side of the outer wall of the small arm rod 101 through the check auxiliary element screw 606, and its position is slightly higher than the check-out trigger element 505. An obtuse-angle cutting groove structure is machined on the bottom edge of the check auxiliary element 605. The check member mounting shaft 608 is horizontally mounted between the shaft holes provided inside the check housing 603, the check member 607 is mounted on the check member mounting shaft 608 through the mounting hole in the middle thereof, the check member sliding pin 609 passes through the mounting hole at the tail of the check member 607 and is connected to the check member 607. The check guide post 610 is mounted on the top side of the outer wall of the large arm rod 103 through the check guide post screw 611. The check guide post 610 extends upward and a slotted notch 610-1 is machined in the middle at the top for insertion and mating with the check member sliding pin 609. The check torsion spring mounting shaft 613 is horizontally mounted between the shaft holes provided outside the check housing 603. The check torsion spring 612 is divided into two and symmetrically sleeved on the check torsion spring mounting shaft 613 on both sides of the check member 607. The check torsion spring 612 is in a compressed state throughout the working process and always has a rotational tendency to return to its natural state. One end abuts against the inner top surface of the check housing 603, and the other end abuts against the check member sliding pin 609. Under the pressure provided by the check torsion spring 612, the check member 607 always has a torque around the axis of the check member mounting shaft 608 to turn towards the check auxiliary element 605. In the state to be checked (i.e., the state where the small arm rod 101 is not fully extended), the check member sliding pin 609 is always tangent to the outer groove wall of the slotted notch 610-1 at the top of the check guide post 610.

[0039] To more clearly show the action state of the check unit 6, in combination with Figure 11 as shown, define the check plane B-B as the plane exactly in the middle of the two check units 6. The check unit 6 is symmetric about the check plane B-B. The check plane B-B is perpendicular to the check-out plane A-A, and the intersection line is the central axis of the entire robotic arm joint. Cut open facing the check plane B-B and take the right-side section as an example to illustrate the principle. In combination with Figure 13As shown, the check torsion spring 612 provides a counterclockwise torque to the check member 607. In the state to be checked, there is no overlapping area between the check member 607 and the check auxiliary element 605. After the check state is completely released, there is no relative movement between the check auxiliary element 605 and the check housing 603, and the check auxiliary element 605 is located above the check member 607. As the small arm rod 101 drives the middle arm rod 102 to extend, relative movement occurs between the middle arm rod 102 and the large arm rod 103. The check member 607 extends with the middle arm rod 102 and rotates counterclockwise under the action of the check torsion spring 612 until the head 607-1 of the check member contacts the support plane 605-1 at the bottom of the check auxiliary element 605, and the check member 607 stops rotating. An inclined surface 607-2 can be machined on the edge of the head 607-1 of the check member. At this time, the inclined surface 607-2 contacts the transition inclined surface 605-2 at the bottom of the check auxiliary element 605, so as to firmly lock the fully extended small arm rod 101 and prevent it from retracting. At the same time, the check pin 609 of the check member changes from moving obliquely along the inclined slot 610-1 at the top of the check guide post 610 to moving vertically along the axis of the arm rod, and the check pin 609 of the check member disengages from the return guide post 610, and the check action is completed.

[0040] The described transmission system 7 adopts the form of ball screw drive and includes a rotary joint 701, joint mounting screws 702, joint mounting parts 703, joint mounting part connection screws 704, main drive screw 705, screw mounting screws 706, joint screw adapter 707, joint screw adapter mounting screws 708, forearm roller nut assembly 709, middle arm roller nut assembly 710, nut assembly mounting screws 711 and joint mounting part positioning pins 712. Its function is to control the telescopic movement of the entire robotic arm joint. The rotary joint 701 integrates an angle sensor and a torque sensor inside, which can perform real-time and accurate measurement and feedback on the rotation angle and torque output by the joint. Among them, the joint mounting part 703 is circumferentially positioned by the joint mounting part positioning pin 712 and then fixed to the inner bottom end of the large arm rod interface adapter 206 by the joint mounting part connection screws 704. The rotary joint 701 is mounted on the joint mounting part 703 through the joint mounting screws 702. A wire routing hole is machined on the side of the joint mounting part 703. The joint screw adapter 707 is mounted on the output flange of the rotary joint 701 through the joint screw adapter mounting screws 708. The main drive screw 705 is mounted on the joint screw adapter 707 through the screw mounting screws 706. The forearm roller nut assembly 709 and the middle arm roller nut assembly 710 are respectively mounted on the inner bottom of the forearm rod 101 and the middle arm rod 102 through the nut assembly mounting screws 711. The main drive screw 705 is divided into a threaded section and a cylindrical section from top to bottom. The parameters of its threaded section are unique and have a self-locking characteristic. When the entire robotic arm joint is in the initial contracted state, the forearm roller nut assembly 709 meshes with the threaded section of the main drive screw 705, and the middle arm roller nut assembly 710 is located on the cylindrical section of the drive screw 705.

[0041] In view of the fact that the robotic arm joints can be divided into a fully extended mode with a fixed elongation to the maximum length and a segmented extension mode that can be telescopically adjusted as required within the maximum length range, accordingly, the wire routing units configured for the robotic arm joints in the two modes are also divided into two modes, namely, the wire routing unit in the fully extended mode and the wire routing unit in the segmented extension mode. The corresponding arm rod units 1 will be slightly different. Below, the three rod segments corresponding to the wire routing unit in the fully extended mode are denoted as the full small arm rod 101-1, the full middle arm rod 102-1, and the full large arm rod 103-1, and the three rod segments corresponding to the wire routing unit in the segmented extension mode are denoted as the segmented small arm rod 101-2, the segmented middle arm rod 102-2, and the segmented large arm rod 103-2 for description. The differences are as follows: Multiple wire grooves are machined inside the multiple guiding bosses on the outer walls of the full small arm rod 101-1, the full middle arm rod 102-1, and the full large arm rod 103-1. At the same time, a plurality of wire holes are evenly machined circumferentially at the bottom of the side walls of the full small arm rod 101-1 and the full middle arm rod 102-1. A plurality of electrical connector mounting bosses are integrally provided above the plurality of wire holes at the bottom of the outer wall of the full small arm rod 101-1. A plurality of electrical connector mounting bosses are integrally provided at the top of the inner wall of the full middle arm rod 102-1. A plurality of electrical connector mounting bosses are integrally provided above the plurality of wire holes at the bottom of the outer wall of the full middle arm rod 102-1. A plurality of electrical connector mounting bosses are integrally provided at the top of the inner wall of the full large arm rod 103-1. The multiple guiding bosses on the outer walls of the segmented small arm rod 101-2 and the segmented middle arm rod 102-2 are of solid structure and do not require machining of wire holes. The electrical connector mounting bosses corresponding to the segmented small arm rod 101-2, the segmented middle arm rod 102-2, and the segmented large arm rod 103-2 serve as limit bosses to prevent the segmented small arm rod 101-2 and the segmented middle arm rod 102-2 from overextending and disengaging.

[0042] The wire routing unit in the fully extended mode includes four sets of electrical connectors and three sets of composite cables. The four sets of electrical connectors are denoted as electrical connector group one 301-1, electrical connector group two 301-2, electrical connector group three 301-3, and electrical connector group four 301-4. After the full small arm 101-1 is fully extended, electrical connector group one 301-1 and electrical connector group two 301-2 are docked and mated with each other. After the full middle arm 102-1 is fully extended, electrical connector group three 301-3 and electrical connector group four 301-4 are docked and mated with each other. The three sets of composite cables are denoted as composite cable group one 303-1, composite cable group two 303-2, and composite cable group three 303-3, which can transmit both power and control and image signals. Among them, electrical connector group one 301-1 is installed on multiple electrical connector mounting bosses at the bottom of the outer wall of the full small arm 101-1 through electrical connector mounting screws 302 with the contact heads facing upward. Electrical connector group two 301-2 is installed on multiple electrical connector mounting bosses at the top of the inner wall of the full middle arm 102-1 through electrical connector mounting screws 302 with the contact heads facing downward. Electrical connector group three 301-3 is installed on multiple electrical connector mounting bosses at the bottom of the outer wall of the full middle arm 102-1 through electrical connector mounting screws 302 with the contact heads facing upward. Electrical connector group four 301-4 is installed on multiple electrical connector mounting bosses at the top of the inner wall of the full large arm 103-1 through electrical connector mounting screws 302 with the contact heads facing downward. Composite cable group one 303-1 is laid in the wire routing groove of the full large arm 103-1 and connects electrical connector group four 301-4 to the electrical contact pins of the large arm interface 202. Composite cable group two 303-2 is laid in the wire routing groove of the full small arm 101-1 and connects electrical connector group one 301-1 to the electrical contact pins of the small arm interface 201. Composite cable group three 303-3 is laid in the wire routing groove of the full middle arm 102-1 and connects electrical connector group two 301-2 to electrical connector group three 301-3. By setting up the wire routing groove to lay the cables, there is no need to contact the internal structure to avoid interference. At the same time, during the entire telescoping process, there is no relative movement between the cables and the arm, thus realizing the safe and reliable internal installation of the cables and minimizing the interference to the overall system design to the greatest extent.

[0043] The segmented extension mode wiring unit includes an inter-segment transfer module 401, an inter-segment transfer module connecting screw 402, a small arm rod wall-attached cable 403, a middle arm rod spiral cable 404, and a large arm rod spiral cable 405. Among them, two inter-segment transfer modules 401 are provided and are respectively installed on the edge plane areas of the small arm rod roller nut assembly 709 and the middle arm rod roller nut assembly 710 through the inter-segment transfer module connecting screws 402. The inter-segment transfer module 401 has the functions of signal processing and amplification, and can effectively overcome the attenuation failure caused by the long transmission of some signal lines. The small arm rod wall-attached cable 403, the middle arm rod spiral cable 404, and the large arm rod spiral cable 405 can transmit both power and control and image signals. The small arm rod wall-attached cable 403 is attached to the inner wall of the sub-small arm rod 101-2 through a clip and connects the electrical contact pins of the small arm rod interface 201 to the inter-segment transfer module 401 on the small arm rod roller nut assembly 709. The middle arm rod spiral cable 404 is built into the sub-middle arm rod 102-2 and connects the two inter-segment transfer modules 401 on the small arm rod roller nut assembly 709 and the middle arm rod roller nut assembly 710. The large arm rod spiral cable 405 is built into the sub-large arm rod 103-2 and connects the electrical contact pins of the large arm rod interface 202 to the inter-segment transfer module 401 on the middle arm rod roller nut assembly 710. The diameters of the middle arm rod spiral cable 404 and the large arm rod spiral cable 405 are designed to maintain a sufficient safety distance from the main drive lead screw 705 in both the fully retracted state and the fully extended state of the arm rod to avoid cable wear. Using the inter-segment transfer module 401 to connect each section of the cable can effectively avoid the wear of each roller nut assembly caused by a single spiral cable running through from beginning to end, thus realizing the safe and reliable internal installation of the cable and minimizing the interference to the overall system design to the greatest extent.

[0044] In addition, the segmented extension mode should also be configured with a sensing system to detect whether each section of the arm rod has been fully extended. Since the fully extended mode is directly extended to a fixed maximum length for use, there is no need to configure it.

[0045] The sensing system includes a permanent magnet 801, a Hall sensor 802, a Hall sensor mounting screw 803, and a Hall sensor connecting wire 804. Two permanent magnets 801 are provided and are respectively adhered to the top inner walls of the sub-middle arm rod 102-2 and the sub-large arm rod 103-2. Two Hall sensors 802 are also provided and are respectively installed on the edge plane areas of the small arm rod roller nut assembly 709 and the middle arm rod roller nut assembly 710 through the Hall sensor mounting screws 803. The Hall sensor 802 is connected to the corresponding inter-segment transfer module 401 through the Hall sensor connecting wire 804. When the sub-small arm rod 101-2 and the sub-middle arm rod 102-2 are fully extended, the Hall sensor 802 cooperates with the permanent magnet 801 to detect that the corresponding arm rod is in the fully extended state.

[0046] Before the active telescopic space robotic arm joint of the present invention leaves the factory, parameter calibration of each internal sensor and joint debugging and testing of each part are completed to ensure accurate force and position output under actual working conditions. In particular, the combined calibration between the Hall sensor 802 and the angle sensor in the rotary joint 701 in the segmented extension mode, and the combined calibration between the maximum extension size and the angle sensor in the rotary joint 701 in the fully extended mode.

[0047] After being launched into orbit, it is stored in the tool payload package as a joint module. When a robot or robotic arm performing an on-orbit assembly task needs to install the active telescopic space robotic arm joint of the present invention, the genderless electro-mechanical interface of the part of the robot or robotic arm to be installed is disconnected, the original joint module or tool is put back into the payload package, and then it is connected to the boom rod interface 202 on the active telescopic space robotic arm joint of the present invention to complete the installation of the active telescopic space robotic arm joint of the present invention. If other joints, tools, and payloads need to be installed later, the entire robot or robotic arm can be controlled to dock the remaining joints, tools, and payloads to be installed on the forearm rod interface 201.

[0048] The following illustrates the specific implementation method through the process of the active telescopic space robotic arm joint of the present invention directly extending from the initial state to the longest state and then contracting from the longest state to the initial state.

[0049] In the extension stage: The joint receives an elongation instruction, and the rotary joint 701 outputs a positive rotational motion, which is transmitted to the main transmission lead screw 705 to drive the forearm rod roller nut assembly 709 engaged therewith to generate a linear motion axially away from the rotary joint 701. In the initial stage of the extension of the forearm rod 101, the middle arm rod 102 is kept in its original position under the action of the stop unit 5 and cannot extend prematurely.

[0050] As the small arm 101 extends, the stop-out trigger element 505 gradually approaches the stop-out member 507, and the check-assist element 605 gradually approaches the check member 607 until the upper teeth 505-1 of the stop-out trigger element contact the upper beak 507-2 of the stop-out member, and the stop-out action begins to be released. Looking directly at the stop-out plane A-A, one set of stop-out units 5 on the left is taken as an example for explanation. As the small arm 101 extends, the stop-out trigger element 505 pushes against the stop-out member 507 and rotates counterclockwise. The upper plane 507-1 of the hook-shaped structure of the stop-out member disengages from the lower plane 508-1 of the hook-shaped structure of the stop-out column, and the upper beak 507-2 of the stop-out member gradually moves away from the stop-out trigger element 505. When the upper beak 507-2 of the stop-out member disengages from the upper teeth 505-1 of the stop-out trigger element, under the action of the stop-out torsion spring 510, the stop-out member 507 rotates clockwise in a very short time, causing the lower beak 507-3 of the stop-out member to contact the lower teeth 505-2 of the stop-out trigger element. The stop-out trigger element 505 continues to push against the stop-out member 507 and rotate counterclockwise until the upper surface 507-4 of the stop-out member contacts the lip surface 503-2 of the stop-out housing, and the stop-out unit 5 is completely released from the stop-out state. Looking down perpendicularly to the stop-out plane A-A, at this time, there is no overlapping area between the upper plane 507-1 of the hook-shaped structure of the stop-out member and the lower plane 508-1 of the hook-shaped structure of the stop-out column. At this time, for the fully extended mode, the electrical connector group one 301-1 and the electrical connector group two 301-2 are completed in docking; for the segmented extended mode, the limit boss at the bottom of the outer wall of the sub-small arm 101-2 is in full contact with the limit boss at the top of the inner wall of the sub-middle arm 102-2. The Hall sensor 802 mounted on the roller nut assembly 709 of the small arm is directly opposite to the permanent magnet 801 adhered to the top of the inner wall of the sub-middle arm 102-2, and the Hall sensor 802 sends a signal to the control system indicating that the sub-small arm 101-2 has been fully extended.

[0051] Thereafter, the force on the small arm 101 in the extending direction is conducted to the middle arm 102 through the stop-out member 507, the stop-out housing 503, and the stop-out housing mounting member 501. The force on the small arm 101 in the extending direction drives the middle arm 102 to extend a certain distance. During the process of the middle arm 102 being driven by the small arm 101 to extend, the roller nut assembly 709 of the small arm gradually disengages from the engagement, and the roller nut assembly 710 of the middle arm gradually enters the engagement.

[0052] After the anti-out unit 5 completely releases the anti-out state, there is no relative movement between the check-return auxiliary element 605 and the check-return housing 603. The check-return auxiliary element 605 is located above the check-return part 607, and the check-return unit 6 starts to perform the check-return action. Looking directly at the check-return plane B-B, taking the set of check-return units 6 on the right as an example for illustration. As the small arm rod 101 drives the middle arm rod 102 to extend, relative movement appears between the middle arm rod 102 and the large arm rod 103. The check-return part 607 moves linearly along the axis as it extends with the middle arm rod 102, and at the same time, under the action of the check-return torsion spring 612, it rotates counterclockwise until the head 607-1 of the check-return part touches the support plane 605-1 of the check-return auxiliary element 605, and the check-return part 607 stops rotating. At this time, the upper inclined plane 607-2 of the check-return part 607 contacts the transition inclined plane 605-2 of the check-return auxiliary element 605, thereby firmly clamping the fully extended small arm rod 101 to prevent it from retracting. At the same time, the check-return part sliding pin 609 changes from obliquely moving along the inclined slot 610-1 of the check-return guide post 610 to vertically moving along the axis of the arm rod. The check-return part sliding pin 609 disengages from the return guide post 610, and the check-return action is completed. The middle arm rod 102 changes from being driven by the small arm rod 101 to extend to pushing the small arm rod 101 to extend together. At this time, the rotary joint 701 will rotate to a key number of turns recorded in the calibration stage. For the segmented extension mode, if only the sub-small arm rod 101-2 needs to be extended, the control system will make the rotary joint 701 stop rotating at this moment.

[0053] After that, the middle arm rod 102 is continuously extended to the fully extended state under the drive of the main transmission lead screw 705. When the number of turns of the rotary joint 701 approaches the number of turns at full extension calibrated before leaving the factory, the control system will make it run at a low speed. For the full extension mode, when the control system detects that the small arm rod interface 201 is on line, it means that the electrical connector group three 301-3 and the electrical connector group four 301-4 have also completed docking, and the internal circuits of the full small arm rod 101-1, the full middle arm rod 102-1, and the full large arm rod 103-1 are conducting, that is, all the arm rods have been fully extended. At this time, the control system sends a stop instruction to the rotary joint 701, and the rotary joint 701 stops rotating. For the segmented extension mode, the limit boss at the bottom of the outer wall of the sub-middle arm rod 102-2 is in full contact with the limit boss at the top of the inner wall of the sub-large arm rod 103-2. The Hall sensor 802 installed on the middle arm rod roller nut assembly 710 is directly opposite to the permanent magnet 801 adhered to the top of the inner wall of the sub-large arm rod 103-2. The Hall sensor 802 sends a signal to the control system, indicating that the sub-middle arm rod 102-2 has been fully extended, that is, all the arm rods have been fully extended. At this time, the control system sends a stop instruction to the rotary joint 701, and the rotary joint 701 stops rotating. Thus, the active telescopic space robotic arm joint of the present invention extends from the fully contracted state to the fully extended state.

[0054] It should be emphasized that the active telescopic space manipulator joint of the present invention can only conduct the internal circuit for operation after all the arm rods are fully extended in the fully extended mode, while in the segmented extension mode, it can operate after some segments or all segments are fully extended. The purpose of this setting is to ensure that the check element 6 completes the check action to maintain the corresponding length state more safely and reliably. After the check pin 609 of the check element disengages from the check guide post 610, in the top view direction, the relative position between the two no longer changes, that is, to ensure that the check pin 609 can return to the inclined slot 610-1 along the original path during the retraction stage of the arm rod.

[0055] During the retraction stage: The joint receives a shortening instruction, and the rotary joint 701 outputs a reverse rotary motion, which is transmitted to the main drive lead screw 705, driving the middle arm rod roller nut assembly 710 engaged with it to generate a linear motion along the axis approaching the rotary joint 701. At this time, for the fully extended mode, the third electrical connector group 301-3 and the fourth electrical connector group 301-4 are disengaged. In the initial stage of the retraction of the middle arm rod 102, the small arm rod 101 remains in a fixed relative position with the middle arm rod 102 under the action of the check unit 6 and cannot retract prematurely.

[0056] As the middle arm rod 102 retracts, the check element 607 gradually approaches the check guide post 610, and the stopper 507 gradually approaches the stopper post 508. Until the check pin 609 contacts the inclined slot 610-1 of the check guide post 610, the check action begins to be released. As the middle arm rod 102 continues to retract, the inclined slot 610-1 of the check guide post 610 presses the check pin 609 to rotate clockwise, and the head 607-1 of the check element turns away from the support plane 605-1 of the check auxiliary element 605. At this time, the upper inclined surface 607-2 of the check element 607 gradually disengages from the transition inclined surface 605-2 of the check auxiliary element 605 until the check element 607 returns to the position when the middle arm rod 102 is not extended, and the check unit 6 completely releases the check action. During this process, the middle arm rod roller nut assembly 710 gradually disengages, and the small arm rod roller nut assembly 709 gradually engages. After that, the relative position between the stopper support shaft 511 and the stopper post 508 remains unchanged, and then the stopper unit 5 begins to resume the stopper state. For the fully extended mode, the first electrical connector group 301-1 and the second electrical connector group 301-2 are disengaged.

[0057] As the main drive lead screw 705 drives the roller nut assembly 709 of the small arm to move axially closer to the rotary joint 701, the anti-ejection trigger element 505 gradually moves away from the anti-ejection member 507. Under the action of the anti-ejection torsion spring 510, the anti-ejection member 507 rotates clockwise until the upper plane 507-1 of the hook-shaped structure of the anti-ejection member fits together with the lower plane 508-1 of the hook-shaped structure of the anti-ejection column. The anti-ejection action of the anti-ejection unit 5 is completed, and the anti-ejection state is restored. Thereafter, the small arm 101 is continuously retracted to the fully retracted state under the drive of the main drive lead screw 705. When the number of turns of the rotary joint 701 reaches the number of turns calibrated before leaving the factory at full retraction, the control system commands it to stop rotating. Thus, the active telescopic space robotic arm joint of the present invention is restored from the fully extended state to the fully retracted state.

[0058] It is worth mentioning that the active telescopic space robotic arm joint of the present invention only requires at least three rod segments. The above takes the three-segment type as an example to illustrate its principle, but is not limited to the three-segment telescopic form. The number of rod segments and the supporting mechanism can be increased according to the actual task requirements, and it should also fall within the protection scope of the present invention.

[0059] The active telescopic space robotic arm joint of the present invention can autonomously adjust its own length through the internal transmission system of the joint without relying on other joints. In the segmented extension mode, the number of segments that can be extended and retracted can be adjusted according to the task requirements. Compared with active continuous telescoping, segmented telescoping can take into account both dimensional accuracy and system simplicity. The transmission system adopts a roller screw drive. Inside each arm rod housing except for the outermost arm rod housing, a roller nut assembly is installed to mesh with the screw. The use of a roller screw drive can greatly improve the load-bearing capacity, transmission accuracy, transmission efficiency, and overall stiffness of the telescopic joint, reduce the frictional loss during transmission, suppress vibration, and increase the reliability and service life of the joint. It can extend multiple segments. By carefully arranging the installation positions of the roller nut assemblies and the lengths of the screws, it can be ensured that the extension or retraction of each segment has a sequential order, is independent of each other, and does not interfere with each other. Through the anti-extension and anti-retraction design, the locking and unlocking method is simplified from the traditional method that requires a locking motor and corresponding diameter-changing devices to relying only on mechanical structures, greatly reducing the complexity and mass of the system, significantly improving the reliability and stability of the system, and being more suitable for the requirements of on-orbit assembly tasks in the space environment. It can rely on the standardized electromechanical interfaces at both the head and the tail as joint modules and can be flexibly installed at the root, middle, or end of a robotic arm or a robot according to the task requirements. It can either be a part of the robotic arm body or an end effector, so that the robotic arm or robot equipped with this joint can change its own configuration according to specific task requirements. According to the different requirements of full extension and segmented extension, two forms of wire routing between segments, namely electrical connector wire routing between segments and spiral cable wire routing between segments, are respectively adopted, which can achieve safe and reliable internal wiring of the cables, while minimizing the impact on the overall system design to the greatest extent, significantly simplifying the mass and complexity of the system, greatly improving the reliability and stability of the system, and being more suitable for the requirements of on-orbit assembly tasks in the space environment.

[0060] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes that fall within the meaning and scope of the equivalent conditions of the claims in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0061] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An active telescopic space manipulator joint for on-orbit assembly tasks, characterized in that: It includes a boom unit (1), an electromechanical interface unit (2), a wire routing unit, a stop-out unit (5), a check unit (6), and a transmission system (7); The boom unit (1) includes a small boom (101), a medium boom (102), and a large boom (103) that are nested level by level from the inside out. Guide bosses are respectively provided on the outer walls of the small boom (101) and the medium boom (102), and guide grooves are correspondingly provided on the inner walls of the medium boom (102) and the large boom (103). The movement of the small boom (101) and the medium boom (102) is restricted to only the axial direction through the cooperation of the guide bosses and the guide grooves; The electromechanical interface unit (2) includes a small boom interface (201) installed at the top of the small boom (101) and a large boom interface (202) installed at the bottom of the large boom (103); The wire routing unit is built into the boom unit (1) for cable connection from the large boom interface (202) to the small boom interface (201); The stop-out unit (5) consists of two sets of mechanisms arranged oppositely. Each set of mechanisms includes a stop-out housing (503), a stop-out trigger element (505), a stop-out member (507), and a stop-out post (508). The stop-out housing (503) is installed at the top of the medium boom (102), the stop-out trigger element (505) is installed at the bottom side of the outer wall of the small boom (101), an alveolar structure is provided at the top outside of the stop-out trigger element (505), a beak-shaped structure is provided at the head of the stop-out member (507) to cooperate with the alveolar structure of the stop-out trigger element (505), a hook-shaped structure is provided below the tail of the stop-out member (507), the stop-out post (508) is installed at the top side of the outer wall of the large boom (103) and extends upward and bends inward to provide a hook-shaped structure. The stop-out member (507) is hinged and installed in the stop-out housing (503) and a torsion spring is provided to provide a torque towards the stop-out post (508) so that the hook-shaped structures of the two fit together to restrict the premature extension of the medium boom (102); The check unit (6) consists of two sets of mechanisms arranged oppositely. Each set of mechanisms includes a check housing (603), a check auxiliary element (605), a check member (607), a check member sliding pin (609), and a check guide post (610). The check housing (603) is installed at the top of the medium boom (102), the check auxiliary element (605) is installed at the bottom side of the outer wall of the small boom (101), an obtuse-angle cutting groove structure is machined at the bottom edge of the check auxiliary element (605), the check member sliding pin (609) is connected to the mounting hole at the tail of the check member (607), the check guide post (610) is installed at the top side of the outer wall of the large boom (103) and extends upward to provide an inclined slot opening (610-1) for insertion and cooperation with the check member sliding pin (609). The check member (607) is hinged and installed in the check housing (603) and a torsion spring is provided to provide a torque towards the check auxiliary element (605). After the check member sliding pin (609) disengages from the inclined slot opening (610-1), the check member (607) supports the bottom edge of the check auxiliary element (605) to prevent the fully extended small boom (101) from retracting; The transmission system (7) includes a rotary joint (701), a main transmission lead screw (705), a forearm roller nut assembly (709) and a middle arm roller nut assembly (710). The rotary joint (701) is coaxially fixed at the inner bottom of the boom (103) and connected to the main transmission lead screw (705). The main transmission lead screw (705) is divided into a threaded section and a cylindrical section from top to bottom. The forearm roller nut assembly (709) and the middle arm roller nut assembly (710) are respectively coaxially fixed at the inner bottom of the forearm (101) and the middle arm (102). In the initial contracted state, the forearm roller nut assembly (709) meshes with the threaded section, and the middle arm roller nut assembly (710) is located on the cylindrical section.

2. The active telescopic space manipulator joint for on-orbit assembly tasks according to claim 1, wherein: The cable routing unit is divided into two types: a fully extended mode cable routing unit and a segmented extended mode cable routing unit. For the fully extended mode cable routing unit, cable grooves are machined on the inner sides of the guide bosses of the forearm (101), the middle arm (102) and the boom (103). At the same time, cable holes are machined at the bottoms of the side walls of the forearm (101) and the middle arm (102). Electric connector groups are respectively installed at the bottom of the outer wall of the forearm (101), the top of the inner wall of the boom (103), and the top and bottom of the inner and outer walls of the middle arm (102). When the arm unit (1) is fully extended, the electric connector groups at the bottom of the outer wall of the forearm (101) and the top of the inner wall of the middle arm (102) are docked and matched. The electric connector groups at the bottom of the outer wall of the middle arm (102) and the top of the inner wall of the boom (103) are docked and matched. The electric connector group at the bottom of the outer wall of the forearm (101) is connected to the forearm interface (201), the two electric connector groups at the top and bottom of the inner and outer walls of the middle arm (102), and the electric connector group at the top of the inner wall of the boom (103) is connected to the boom interface (202) through composite cable groups respectively, and the composite cable groups are evenly arranged in the corresponding cable grooves. For the segmented extended mode cable routing unit, limit bosses are respectively arranged at the bottom of the outer wall of the forearm (101), the top of the inner wall of the boom (103), and the top and bottom of the inner and outer walls of the middle arm (102) to prevent over-extension. Section-to-section transfer modules (401) are respectively installed in the edge plane areas of the forearm roller nut assembly (709) and the middle arm roller nut assembly (710). A forearm wall-attached cable (403) is arranged on the inner wall of the forearm (101) to connect the forearm interface (201) to the section-to-section transfer module (401) on the forearm roller nut assembly (709). A middle arm spiral cable (404) is arranged inside the middle arm (102) to connect the two section-to-section transfer modules (401) on the forearm roller nut assembly (709) and the middle arm roller nut assembly (710). A boom spiral cable (405) is arranged inside the boom (103) to connect the boom interface (202) to the section-to-section transfer module (401) on the middle arm roller nut assembly (710).

3. The active telescopic space manipulator joint for on-orbit assembly tasks according to claim 2, wherein: The segmented stretching mode wiring unit is configured with a sensing system, and the sensing system includes two permanent magnets (801) and two Hall sensors (802). The two permanent magnets (801) are respectively adhered to the top of the inner walls of the middle arm rod (102) and the large arm rod (103), and the two Hall sensors (802) are respectively installed in the edge plane areas of the small arm rod roller nut assembly (709) and the middle arm rod roller nut assembly (710) and are connected to the corresponding inter-segment transfer module (401) through connecting wires.

4. The active telescopic space manipulator joint for on-orbit assembly tasks according to claim 1, characterized in that: Both the small arm rod interface (201) and the large arm rod interface (202) have the characteristic of genderless structure.

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