On-orbit service space robot

Abstract

The invention discloses an on-orbit service space robot, and relates to the technical field of on-orbit robots. The on-orbit service space robot comprises a star body, a left arm assembly and a right arm assembly are arranged on the two sides of the star body through initial joints, and actuator interfaces are formed in the tail ends of the left arm assembly and the right arm assembly; the left arm assembly and the right arm assembly are each of a mechanical arm structure, each mechanical arm structure comprises a mechanical arm body, and a small arm capable of stretching out and drawing back in the axial direction is arranged on each mechanical arm body. According to the on-orbit service space robot, operation tasks such as on-orbit assembly, repair and maintenance of a space structure can be achieved, the enveloping limitation of a rocket fairing in active service is met, and the problems that a traditional space robot is limited in structure size, low in deployment efficiency, poor in tail end operation flexibility and the like are solved.

Description

Technical Field

[0001] This invention relates to the field of on-orbit robot technology, and more specifically to an on-orbit service space robot. Background Technology

[0002] As space missions become larger and more modular, the need for on-orbit assembly of ultra-large space structures such as space solar power stations, large telescopes, and lunar bases is becoming increasingly urgent. Limited by rocket fairing size and payload capacity, these structures cannot be launched into orbit in a single launch and must rely on space robots for on-orbit assembly and maintenance.

[0003] Currently, mainstream space robots internationally, such as Canadaarm2 and Japan's JEMRMS, are mostly small, attached robotic arms with an operating range of less than 20 meters. They also rely on space stations or spacecraft platforms and cannot independently complete on-orbit operations of structures up to 100 meters in size.

[0004] The newest robotic arm on the International Space Station is the European Space Agency's (ESA) ERA, launched and integrated with the ISS in 2021. The arm is 11 meters long, with seven joints and two booms, consisting of two end effectors, each with a wrist joint at the end. These joints allow the robotic arm to move within the Science module and other Russian modules. The ERA is primarily used for the on-orbit assembly of external equipment, mainly from the Science module, within the Russian modules, such as installing heat shields and extended airlocks, and for conducting other extravehicular services, significantly reducing the workload for astronauts.

[0005] In 2016, researchers from Caltech and NASA proposed an architecture and conceptual design for a Robotically Assembled Modular Space Telescope (RAMST) that would be assembled in orbit. The primary mirror assembly would be performed by a multi-limbed robot that would work alongside the telescope, navigating the primary mirror truss structure and performing assembly and maintenance tasks throughout the telescope's lifespan.

[0006] However, the existing on-orbit assembly robots have a relatively small operating range, which cannot meet the needs of assembling large space equipment and other tasks. In addition, most robots rely on space stations or spacecraft platforms and cannot operate independently, which limits the flexibility of the mission. Summary of the Invention

[0007] The purpose of this invention is to provide an on-orbit service space robot that can perform on-orbit assembly, repair and maintenance of space structures, and meet the envelope constraints of existing rocket fairings, thus solving the problems of limited structural size, low deployment efficiency and poor end-effector flexibility of traditional space robots.

[0008] The technical solution of the present invention to solve the above technical problems is as follows: an on-orbit service space robot is provided, including a star body, a left arm assembly and a right arm assembly are set on both sides of the star body through initial joints, and an actuator interface is set at the end of the left arm assembly and the right arm assembly;

[0009] The left arm assembly includes the first segment of the left arm. One end of the first segment of the left arm is connected to the main body of the star through an initial joint, and the other end of the first segment of the left arm is connected in sequence to the second, third, fourth and fifth segments of the left arm through an interarm joint.

[0010] The right arm assembly includes a right arm first segment. One end of the right arm first segment is connected to the main body of the star through an initial joint. The other end of the right arm first segment is connected to the right arm second segment and the right arm third segment in sequence through an interarm joint. The end of the right arm third segment is connected to the upper split arm first segment and the lower split arm first segment through a split arm joint. The upper split arm first segment and the lower split arm first segment are connected to the upper split arm second segment and the lower split arm second segment through an interarm joint.

[0011] Both the left arm assembly and the right arm assembly are robotic arm structures. The robotic arm structure includes a robotic arm body, on which a forearm that can extend and retract along the axis is provided.

[0012] The robot's left arm segments 1 to 5, and right arm segments 1 to 3, are sequentially connected via inter-arm joints, forming a series structure. The right arm segment 3, along with the upper and lower sub-arm segments 1, adopts a parallel sub-arm structure. The entire robot is divided into a left arm assembly and a right arm assembly. The left arm assembly consists of 5 forearm segments, each of which can extend and retract within a range of 9-15 meters. Each forearm segment is connected by a 2-DOF joint. The right arm assembly integrates a deployable sub-arm structure on the two distal forearm segments. Compared to traditional dual independent arm structures, this reduces structural weight and manufacturing costs while ensuring equivalent operational functions, and improves task efficiency through multi-terminal collaborative operation. The first two segments of both arms are relatively thick, with a diameter of 0.7 meters, while the remaining arms are 0.5 meters in diameter, optimizing weight distribution while maintaining structural strength. Through a folding design, the robot's configuration can be adapted to the envelope constraints of the Long March 5B rocket fairing currently in service.

[0013] Furthermore, a transmission assembly is installed within the inter-arm joint. This assembly includes a joint servo motor, whose output is sequentially connected to a drive worm gear, a transmission gear, a transmission bevel gear set, and a rotating shaft. The rotating shaft is connected to the forearm or the main body of the next segment of the robotic arm. Meanwhile, the initial joint has a similar structure to the inter-arm joint, but it has only one set of transmission components (one degree of freedom) for the free rotation of the first segment of the left or right arm.

[0014] The joint servo motor drives the drive worm gear to rotate, which in turn drives the transmission gear to rotate, which in turn drives the coaxial transmission bevel gear set to rotate, thus causing rotation around the rotation axis. The interarm joint uses two independent joint servo motors to adjust and control the two degrees of freedom of the joint.

[0015] Furthermore, taking the first and second segments of the right arm as examples, the forearm of the first segment is connected to the interarm joint, allowing the forearm to extend and retract along the axis of the first segment. The interarm joint can rotate freely 360° relative to the forearm. The forearm of the second segment is connected to the other side of the interarm joint, and the forearm of the second segment can also rotate 360° relative to the interarm joint. The connections of other interarm joints are similar. The single-segment robotic arm structure achieves three degrees of freedom through a combination of "extension + rotation + rotation," giving the robotic arm a highly flexible spatial movement capability. This robot configuration uses 36 internal servo motors to independently control the 36 degrees of freedom, enabling it to complete various on-orbit service tasks.

[0016] Furthermore, the telescopic range of the left and right arm components is 45-75 meters, with a total degree of freedom of 36.

[0017] Furthermore, the split-arm joint includes two rotatably connected parallel joints, Parallel Joint 1 and Parallel Joint 2. Parallel Joint 1 is connected to the forearm of the third segment of the right arm and the first segment of the lower split-arm, respectively, while Parallel Joint 2 is connected to the forearm of the first segment of the upper split-arm. This parallel split-arm structure further expands the working range and makes the split-arm's movement more diverse, adapting to the multi-directional operational needs of complex spatial structures.

[0018] Furthermore, the main body of the robotic arm is equipped with an internal servo motor, which drives the forearm to extend and retract via a worm gear.

[0019] Furthermore, actuator interfaces are provided at the ends of the fifth section of the left arm, the second section of the upper arm, and the second section of the lower arm. These actuator interfaces are modular and can be connected to different actuator ends according to task requirements.

[0020] Furthermore, cameras are installed on the second, fourth, and fifth segments of the left arm, the second segment of the right arm, the first and second segments of the upper and lower arms, and the second segment of the upper and lower arms, respectively. These cameras are connected to the vision processing system. The cameras on the second, fourth, and second segments of the left and fourth arms, the second and first segments of the right and upper arms, respectively, help determine the position, posture, and motion state of the robotic arms, preventing collisions between them and forming the basis for precise control. Simultaneously, the robot is equipped with a vision processing system, and the cameras can be used to detect obstacles, plan paths, and achieve partial autonomous operation, improving task efficiency and safety. The cameras located at the robot's end effector on the fifth segment of the left arm, the second segment of the upper arm, and the second segment of the lower arm, respectively, use the vision system to identify and locate target objects (such as assembly materials, end effector tools, etc.), providing guidance information for operations such as grasping, docking, repair, and assembly, and assisting in target identification and positioning.

[0021] Furthermore, the diameters of the first, second, first, and second segments of the left arm, the right arm, and the right arm are 0.6-1 meters; the diameters of the third, fourth, and fifth segments of the left arm, the third segment of the right arm, the first segment of the upper arm, the first segment of the lower arm, the second segment of the upper arm, and the second segment of the lower arm are 0.4-0.6 meters.

[0022] Furthermore, the diameters of the first and second sections of the left arm, the first and second sections of the right arm, and the second section of the right arm are 0.7 meters, while the diameters of the third, fourth, and fifth sections of the left arm, the third section of the right arm, the first section of the upper arm, the first section of the lower arm, the second section of the upper arm, and the second section of the lower arm are 0.5 meters. This optimizes weight distribution while ensuring structural strength.

[0023] The entire robot can be folded and stored within the fairing of the Long March 5B rocket during launch, meeting the envelope limitations of current launch vehicles and enabling it to be sent into a predetermined orbit in a single launch. Each joint adopts a modular design, possessing on-orbit deployment and locking capabilities, ensuring high reliability and maintainability in the space environment. During launch, the robot is folded and stored within the rocket fairing; after entering orbit, through the rotation and adjustment of the initial joints, inter-arm joints, and segmental arm joints, the robotic arms unfold sequentially, forming a robotic arm structure with an extension length of hundreds of meters. The end effector can perform high-precision operations in space, completing tasks such as grasping, assembly, and maintenance by changing different modular task tools. Through the coordinated movement of the left and right arm components and the fine adjustment of the segmental arm joints, it can provide comprehensive services to large space structures.

[0024] The present invention has the following beneficial effects:

[0025] 1. The on-orbit service space robot of the present invention adopts a modular multi-joint serial and parallel structure, which has high rigidity, large extension range and high flexibility, and is suitable for fine operation of large space structures in on-orbit service tasks; and because the robotic arm of the robot configuration is long enough and has a large number of degrees of freedom, the end of the robotic arm can reach any point in space within a certain working range, thereby completing on-orbit service operations.

[0026] 2. This on-orbit service space robot adopts a modular joint design that combines serial and parallel connections. Through the deployment and coordination of various levels of robotic arms, it can achieve a deployment length of hundreds of meters, making it suitable for operation tasks on large space structures. In the launch state, it can be completely housed within the rocket fairing, meeting the envelope constraints. The parallel joint structure improves the positioning accuracy and stability of the end effector. Multi-joint collaborative control adapts to complex space environments and mission requirements. The modular design facilitates on-orbit maintenance and replacement, improving system lifespan and mission adaptability. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the on-orbit service space robot of the present invention;

[0028] Figure 2 This is a cross-sectional view of the robotic arm structure of the present invention;

[0029] Figure 3 This is a folding diagram of the on-orbit service space robot of the present invention;

[0030] Figure 4 This is a schematic diagram of the on-orbit service space robot of the present invention placed in the fairing;

[0031] Figure 5 This is a sectional view of the interbrachial joint;

[0032] Figure 6 This is a schematic diagram of the connection of the interarm joint;

[0033] Figure 7 This is a schematic diagram of a split-arm joint;

[0034] Figure 8 This is a schematic diagram of the multi-arm collaborative assembly of the on-orbit service space robot of the present invention;

[0035] Figure 9 This is a schematic diagram of the dual-arm assembly and single-arm gripping of the on-orbit service space robot of the present invention;

[0036] Figure 10 This is a schematic diagram of the on-orbit service space robot of the present invention, in which the right arm replaces the end effector of the left arm;

[0037] In the diagram: 1. Main body of the celestial body; 2. Initial joint; 3. Left arm assembly; 301. First segment of the left arm; 302. Second segment of the left arm; 303. Third segment of the left arm; 304. Fourth segment of the left arm; 305. Fifth segment of the left arm; 4. Right arm assembly; 401. First segment of the right arm; 402. Second segment of the right arm; 403. Third segment of the right arm; 404. First segment of the upper arm; 405. First segment of the lower arm; 406. Second segment of the upper arm; 407. Second segment of the lower arm; 5. Inter-arm joint; 501. Joint servo motor; 502. Drive worm gear one; 503. Transmission gear; 504. Transmission bevel gear set; 505. Rotation shaft; 6. Split arm joint; 601. Parallel joint one; 602. Parallel joint two; 7. Main body of the robotic arm; 701. Forearm; 702. Intra-arm servo motor; 703. Drive worm gear two; 8. Actuator interface. Detailed Implementation

[0038] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0039] An embodiment of the present invention provides an on-orbit servicing space robot, such as... Figure 1 As shown, the system includes a main body 1. A left arm assembly 3 and a right arm assembly 4 are connected to both sides of the main body 1 via initial joints 2. Actuator interfaces 8 are located at the ends of the left arm assembly 3 and right arm assembly 4. The left arm assembly 3 includes a first segment 301, one end of which is connected to the main body 1 via the initial joint 2. The other end of the first segment 301 is connected sequentially to a second segment 302, a third segment 303, a fourth segment 304, and a fifth segment 305 via interarm joints 5. The right arm assembly 4 includes a first segment 401. One end of the first segment 401 of the right arm is connected to the main body 1 of the celestial body via the initial joint 2. The other end of the first segment 401 of the right arm is connected to the second segment 402 and the third segment 403 of the right arm via the interarm joint 5. The end of the third segment 403 of the right arm is connected to the first segment 404 of the upper arm and the first segment 405 of the lower arm via the split arm joint 6. The first segment 404 of the upper arm and the first segment 405 of the lower arm are connected to the second segment 406 of the upper arm and the second segment 407 of the lower arm via the interarm joint 5. The left arm assembly 3 and the right arm assembly 4 are both robotic arm structures (e.g., Figure 2 As shown, the robotic arm structure includes a robotic arm body 7, on which a small arm 701 that can extend and retract along the axial direction is provided.

[0040] The robot's left arm segments 301 to 305 and right arm segments 401 to 403 are connected sequentially via inter-arm joints 5, forming a series structure. The right arm segment 403, along with the upper and lower sub-arm segments 404 and 405, adopts a parallel sub-arm structure. The entire robot is divided into a left arm assembly 3 and a right arm assembly 4. The left arm assembly 3 consists of five forearm segments 701, each with an adjustable length of 9-15 meters, connected by a 2-DOF joint. The right arm assembly 4 integrates a deployable sub-arm structure on the two distal forearm segments 701. Compared to traditional dual independent arm structures, this reduces structural weight and manufacturing costs while maintaining functional equivalence, and improves task efficiency through multi-terminal collaborative operation. The first two segments of both arms are relatively thick, with a diameter of 0.7 meters, while the remaining arms are 0.5 meters in diameter, optimizing weight distribution while ensuring structural strength. Through folding design (such as) Figure 3 and Figure 4 As shown in the figure, the robot configuration can be adapted to the envelope constraint of the fairing of the currently in-service Long March 5B rocket.

[0041] like Figure 5 As shown, the interarm joint 5 is equipped with a transmission assembly, which includes a joint servo motor 501. The output of the joint servo motor 501 is sequentially connected to a drive worm gear 502, a transmission gear 503, a transmission bevel gear set 504, and a rotating shaft 505. The rotating shaft 505 is connected to the forearm 701 or the next segment of the robotic arm body 7. Meanwhile, the structure of the initial joint 2 is similar to that of the interarm joint 5, but it has only one set of transmission components (one degree of freedom) for the free rotation of the first segment 301 of the left arm or the first segment 401 of the right arm. The joint servo motor 501 drives the drive worm gear 502 to rotate, which in turn drives the transmission gear 503 to rotate, which in turn drives the coaxial transmission bevel gear set 504 to rotate, thus driving the rotation around the rotating shaft 505. The interarm joint 5 uses two independent joint servo motors 501 to adjust and control the two degrees of freedom of the joint.

[0042] Specifically, such as Figure 6As shown, taking the first segment 401 and the second segment 402 of the right arm as examples, the forearm 701 of the first segment 401 is connected to the interarm joint 5. The forearm 701 can extend and retract along the axis of the first segment 401. The interarm joint 5 can rotate freely 360° relative to the forearm 701. The main body 7 of the second segment 402 is connected to the other side of the interarm joint 5, and the forearm 701 of the second segment 402 can also rotate 360° relative to the interarm joint 5. The connections of other interarm joints 5 are similar. The single-segment robotic arm structure achieves three degrees of freedom through a combination of "extension + rotation + rotation," giving the robotic arm a highly flexible spatial movement capability. The extension range of the left arm assembly 3 and the right arm assembly 4 is 45-75 meters, with a total of 36 degrees of freedom. This robot configuration uses 36 internal servo motors to independently control the 36 degrees of freedom, enabling it to complete various on-orbit service tasks.

[0043] like Figure 7 As shown, the split-arm joint 6 includes a first parallel joint 601 and a second parallel joint 602 that are rotatably connected. The first parallel joint 601 is connected to the forearm 701 of the third section 403 of the right arm and the first section 405 of the lower split-arm, respectively. The second parallel joint 602 is connected to the forearm 701 of the first section 404 of the upper split-arm. The parallel split-arm structure further expands the working range while making the movement posture of the split-arm more diverse, adapting to the multi-directional operation needs of complex spatial structures. An in-arm servo motor 702 is installed inside the main body 7 of the robotic arm. The in-arm servo motor 702 drives the forearm 701 to extend and retract via a second worm gear 703. Actuator interfaces 8 are provided at the ends of the fifth section 305 of the left arm, the second section 406 of the upper split-arm, and the second section 407 of the lower split-arm. The actuator interfaces 8 are modular interfaces, capable of connecting to different actuator ends according to task requirements.

[0044] Cameras are installed on the second section (302) of the left arm, the fourth section (304) of the left arm, the fifth section (305) of the left arm, the second section (402) of the right arm, the first section (404) of the upper arm, the first section (405) of the lower arm, the second section (406) of the upper arm, and the second section (407) of the lower arm. These cameras are connected to the vision processing system. The cameras on the second section (302) of the left arm, the fourth section (304) of the left arm, the second section (402) of the right arm, the first section (404) of the upper arm, and the first section (405) of the lower arm help determine the position, posture, and motion state of the robotic arms, preventing collisions between the robotic arms and forming the basis for precise control. Simultaneously, the robot is equipped with a vision processing system, and the cameras can be used to detect obstacles, plan paths, and achieve partial autonomous operation, improving task efficiency and safety. The cameras located at the robot's end effector, on the fifth section 305 of the left arm, the second section 406 of the upper arm, and the second section 407 of the lower arm, use a vision system to identify and locate target objects (such as assembly materials, end effector tools, etc.), providing guidance information for operations such as grasping, docking, maintenance, and assembly, and assisting in target identification and positioning.

[0045] The diameters of the left arm's first section (301), left arm's second section (302), right arm's first section (401), and right arm's second section (402) are all 0.7 meters. The diameters of the left arm's third section (303), left arm's fourth section (304), left arm's fifth section (305), right arm's third section (403), upper arm's first section (404), lower arm's first section (405), upper arm's second section (406), and lower arm's second section (407) are all 0.5 meters. Weight distribution was optimized while maintaining structural strength.

[0046] The entire robot can be folded and stored inside the fairing of the Long March 5B rocket in its launch state, meeting the envelope limitations of current launch vehicles and enabling it to be sent into a predetermined orbit in a single launch. Each joint adopts a modular design, possessing on-orbit deployment and locking capabilities, ensuring high reliability and maintainability of the robot in the space environment. During launch, the robot is folded and stored inside the rocket fairing; after entering orbit, through the rotation and adjustment of the initial joint 2, inter-arm joint 5, and split-arm joint 6, the robotic arms unfold sequentially, forming a robotic arm structure with an extension length of hundreds of meters. The end effector can perform high-precision operations in space, completing tasks such as grasping, assembly, and maintenance by changing different modular task tools. Through the coordinated movement of the left arm assembly 3 and the right arm assembly 4, and the fine adjustment of the split-arm joint 6, it can provide comprehensive services to large space structures.

[0047] This on-orbit service space robot has multiple mission modes. Figure 8 This demonstrates a configuration example of multi-arm collaborative assembly of robots, where the ends of three robotic arms work together to complete relatively delicate structural assembly tasks. Figure 9 The demonstration shows a configuration example of a robot assembling with two arms and gripping with one arm. For example, in the assembly of a modular large space telescope, the two arms of the left arm assemble the mirror structure, while the right arm grips the remaining mirror from the cargo spacecraft and drags it to the left arm area, waiting for the left arm to assemble. Figure 10 The demonstration shows a configuration example where the robot's right arm replaces the end effector module of the left arm. The three arms are concentrated near the planetary body. The right arm retrieves the modular end effector stored on the planetary body and installs it at the ends of the two sub-arms of the left arm, thus adapting to different tasks.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An on-orbit servicing space robot, characterized in that, The system includes a main body (1), and a left arm assembly (3) and a right arm assembly (4) are provided on both sides of the main body (1) through an initial joint (2). The ends of the left arm assembly (3) and the right arm assembly (4) are provided with actuator interfaces. The left arm assembly (3) includes a first segment (301) of the left arm. One end of the first segment (301) of the left arm is connected to the main body (1) of the star through the initial joint (2). The other end of the first segment (301) of the left arm is connected in sequence to the second segment (302), the third segment (303), the fourth segment (304), and the fifth segment (305) of the left arm through the interarm joint (5). The right arm assembly (4) includes a right arm first segment (401), one end of which is connected to the star body (1) via the initial joint (2), and the other end of which is connected to a right arm second segment (402) and a right arm third segment (403) via an interarm joint (5). The end of the right arm third segment (403) is connected to an upper split arm first segment (404) and a lower split arm first segment (405) via a split arm joint (6). The upper split arm first segment (404) and the lower split arm first segment (405) are connected to an upper split arm second segment (406) and a lower split arm second segment (407) via an interarm joint (5). The left arm assembly (3) and the right arm assembly (4) are both robotic arm structures. The robotic arm structure includes a robotic arm body (7), and the robotic arm body (7) is provided with a small arm (701) that can extend and retract along the axis.

2. The on-orbit servicing space robot according to claim 1, characterized in that, The interarm joint (5) is provided with a transmission assembly, which includes a joint servo motor (501). The output end of the joint servo motor (501) is connected in sequence to a drive worm gear (502), a transmission gear (503), a transmission bevel gear set (504), and a rotating shaft (505).

3. The on-orbit servicing space robot according to claim 1, characterized in that, The split arm joint (6) includes a rotatably connected parallel joint one (601) and a parallel joint two (602). The parallel joint one (601) is connected to the forearm (701) of the third segment (403) of the right arm and the first segment of the lower split arm, respectively. The parallel joint two (602) is connected to the forearm (701) of the first segment (404) of the upper split arm.

4. The on-orbit servicing space robot according to claim 1, characterized in that, The main body (7) of the robotic arm is equipped with an in-arm servo motor (702), which drives the forearm (701) to extend and retract through the drive worm gear (703).

5. The on-orbit servicing space robot according to claim 1, characterized in that, The fifth section (305) of the left arm, the second section (406) of the upper arm, and the second section (407) of the lower arm are all provided with actuator interfaces (8).

6. The on-orbit servicing space robot according to claim 1, characterized in that, Cameras are provided on the second section (302) of the left arm, the fourth section (304) of the left arm, the fifth section (305) of the left arm, the second section (402) of the right arm, the first section (404) of the upper arm, the first section (405) of the lower arm, the second section (406) of the upper arm, and the second section (407) of the lower arm. The cameras are connected to the vision processing system.

7. The on-orbit servicing space robot according to claim 1, characterized in that, The diameters of the first segment (301) of the left arm, the second segment (302) of the left arm, the first segment (401) of the right arm, and the second segment (402) of the right arm are 0.6-1 meters, and the diameters of the third segment (303) of the left arm, the fourth segment (304) of the left arm, the fifth segment (305) of the left arm, the third segment (403) of the right arm, the first segment (404) of the upper arm, the first segment (405) of the lower arm, the second segment (406) of the upper arm, and the second segment (407) of the lower arm are 0.4-0.6 meters.

8. The on-orbit servicing space robot according to claim 7, characterized in that, The diameter of the first segment (301) of the left arm, the second segment (302) of the left arm, the first segment (401) of the right arm, and the second segment (402) of the right arm is 0.7 meters; the diameter of the third segment (303) of the left arm, the fourth segment (304) of the left arm, the fifth segment (305) of the left arm, the third segment (403) of the right arm, the first segment (404) of the upper arm, the first segment (405) of the lower arm, the second segment (406) of the upper arm, and the second segment (407) of the lower arm is 0.5 meters.

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