A wheel-legged robot with a planetary climbing structure

Abstract

This invention provides a wheeled leg with a planetary climbing structure and a wheeled leg robot. This wheeled leg robot exhibits adaptability to uneven terrain and adjustable overall height, enabling smooth and stable climbing with higher stability and motion efficiency, and lower requirements for joint motors. The wheeled leg includes a torso mechanism, a leg mechanism, and a planetary rotating wheel mechanism; the torso mechanism is movably connected to the leg mechanism; the leg mechanism is movably connected to the planetary rotating wheel mechanism; the torso mechanism houses an energy system and a control system. During climbing, by rotating the triangular planetary wheel structure, one of the secondary planetary wheels acts as a support point, contacting the steps to provide auxiliary support, significantly improving the stability and smoothness of the climbing process. Simultaneously, through the flexible layout of the synchronous belt drive, the rotating joint motor can be moved away from the leg end, optimizing the overall motion performance of the system and improving the compactness and reliability of the mechanical structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of robots, in particular to a wheel-foot leg with a planetary ladder climbing structure and a wheel-foot robot. BACKGROUND

[0002] Wheel robots reduce motion impact through rolling contact, have advantages such as high efficiency, stability and flexibility, and are widely used in fields such as cargo transportation, environmental exploration and disaster relief. However, its movement mode is single, and the obstacle crossing ability is limited, which is difficult to adapt to complex terrain. On the contrary, leg robots have strong terrain adaptability, but have inherent defects such as low moving efficiency and high energy consumption. Therefore, wheel-foot hybrid mobile robots have become a research hotspot, aiming to combine the high efficiency of wheel robots with the obstacle crossing ability of leg robots.

[0003] In complex environments, stairs are one of the most common terrain obstacles. Existing wheel-foot robots mostly use the movement mode of leg robots when climbing stairs, such as jumping or climbing stairs with human-like legs. Such modes have significant defects: higher control complexity is required, precise gait planning and balance are needed, and sensors and algorithms are required; the movement efficiency is low, the action is slow and the energy consumption is large, which is difficult to meet the demand for rapid response; the environmental adaptability is insufficient, and the robustness to changes in stair size is poor, which is prone to instability due to differences in step height. In addition, some wheel-foot robots use wheel group structures, which improve flexibility, but have large fluctuations in the center of gravity when climbing stairs, poor stability, and large volume, making it difficult to adapt to narrow spaces such as residential staircases.

[0004] In summary, existing wheel-foot robots still face technical bottlenecks such as control complexity, low efficiency and insufficient stability in the function of climbing stairs. Therefore, developing a wheel-foot climbing robot that combines movement flexibility, high efficiency and stability is a key technical problem that needs to be broken through in the field. SUMMARY

[0005] In order to solve at least one of the technical problems in the background art, the present application provides a wheel-foot leg with a planetary ladder climbing structure, which can adapt to uneven terrain and adjust the overall height, achieve smooth and stable climbing of stairs, have higher stability and movement efficiency, and have lower requirements for joint motors.

[0006] The technical solution adopted by the present application to solve its technical problems is: the wheel-foot leg with a planetary ladder climbing structure comprises a torso mechanism, a leg mechanism and a planetary flip wheel mechanism.

[0007] The torso mechanism is movably connected with the leg mechanism.

[0008] The leg mechanism is movably connected with the planetary flip wheel mechanism.

[0009] The torso mechanism is internally provided with an energy system and a control system.

[0010] Further, the leg mechanism comprises hip joint motors arranged on both sides of the torso mechanism;

[0011] The output shaft of the hip joint motor is provided with a thigh rack;

[0012] The lower end of the thigh rack is provided with a knee joint motor;

[0013] The output shaft of the knee joint motor is provided with a lower leg rack.

[0014] Further, the lower leg rack is arranged inside the thigh rack.

[0015] Further, the planetary flip wheel mechanism comprises a planetary flip motor arranged at the middle upper part of the lower leg rack;

[0016] The output shaft of the planetary flip motor extends through the side wall of the lower leg rack to the inside, and the output shaft of the planetary flip motor is provided with a flip driving synchronous pulley;

[0017] The lower end of the inside of the lower leg rack is provided with a flip driven synchronous pulley through a bearing and is connected to the flip driving synchronous pulley through a planetary flip synchronous belt;

[0018] The flip driven synchronous pulley is provided with a triangular planetary transmission rack at one end outside the lower leg rack;

[0019] The triangular ends of the inside of the triangular planetary transmission rack are each hinged with a star secondary wheel driven synchronous pulley;

[0020] The outside of the triangular planetary transmission rack is provided with a triangular planetary rack, and the triangular ends of the triangular planetary rack are each provided with a planetary secondary wheel through a planetary wheel shaft inside the triangular planetary rack;

[0021] The three planetary secondary wheels are respectively connected in transmission with the three planetary secondary wheel driven synchronous pulleys;

[0022] The lower end outside the lower leg rack is provided with a planetary secondary wheel motor, and the output shaft of the planetary secondary wheel motor extends through the hollow hole inside the flip driven synchronous pulley to the inside of the triangular planetary transmission rack;

[0023] The output shaft of the planetary secondary wheel motor is provided with a planetary secondary wheel driving synchronous pulley and is located at the center position inside the triangular planetary transmission rack;

[0024] The planetary secondary wheel driving synchronous pulley and the three planetary secondary wheel driven synchronous pulleys are provided with a star secondary wheel synchronous belt therebetween;

[0025] The planetary secondary gear synchronous belt is connected to the planetary secondary gear driving synchronous belt pulley and three planetary secondary gear driven synchronous belt pulleys through multiple synchronous belt tensioning pulleys.

[0026] Furthermore, the number of synchronous belt tensioners is six;

[0027] They are evenly distributed in pairs on the outer side of the planetary secondary gear drive synchronous belt pulley;

[0028] One synchronous belt tensioner in each group is mounted on the side wall of the triangular planetary transmission frame via a fixed shaft, and the other synchronous belt tensioner in each group is mounted on the side wall of the triangular planetary transmission frame via an adjusting bolt structure.

[0029] Furthermore, the planetary secondary gear active synchronous pulley and the flip driven synchronous pulley adopt a concentric shaft design, with the hollow shaft of the planetary secondary gear active synchronous pulley sleeved inside the hollow shaft of the flip driven synchronous pulley and the two connected by bearings.

[0030] Furthermore, both the reversing active synchronous pulley and the reversing driven synchronous pulley have 44 teeth, and the transmission ratio is 1:1.

[0031] The planetary reversing synchronous belt is 8M type, with a bandwidth of 30 mm, a transmission pitch of 240 mm, and a belt length of 840 mm.

[0032] Furthermore, the planetary secondary wheel has a diameter of 230mm and a width of 40mm.

[0033] Furthermore, both the driving and driven synchronous pulleys of the planetary secondary gear have 32 teeth, and the transmission ratio is 1:1. The synchronous belt type of the planetary secondary gear is 14M, the width is 30 mm, and the belt length is 1988 mm.

[0034] The present invention also provides a wheeled-legged robot, comprising the wheeled-legged structure described in any of the preceding claims.

[0035] The beneficial effects of this invention are as follows:

[0036] 1. Based on the existing bipedal robot, this invention replaces the hub motor at the end of the leg with a triangular planetary gear structure. During the climbing process, by flipping the triangular planetary gear structure, one of the secondary planetary gears serves as a support point and contacts the step, thereby providing auxiliary support, significantly improving the stability and smoothness of the climbing process, while reducing control complexity and improving movement efficiency.

[0037] 2. This invention uses synchronous belt drive to replace traditional gear set drive, realizing long-distance simultaneous transmission of three planetary secondary gears. While ensuring accurate transmission ratio, it significantly reduces system weight, effectively reduces the end-effector inertia, and improves the robot's dynamic response capability.

[0038] 3. The synchronous belt drive of the planetary secondary gear used in this invention adopts an outer tensioning method, which increases the wrap angle of the synchronous belt, effectively prevents slippage or tooth skipping, and ensures transmission stability. In addition, the tensioning wheel is fixed at both ends on the slide groove of the triangular transmission frame, which has the function of adjustable tension, further optimizing the compactness and adaptability of the transmission system.

[0039] 4. This invention integrates two motors onto the same frame through the synergistic optimization of hollow shaft design and synchronous belt drive, achieving dual-degree-of-freedom transmission on a single shaft and effectively avoiding the wiring entanglement problem caused by traditional dual-motor series connection. Simultaneously, thanks to the flexible layout of the synchronous belt drive, the tilting joint motor can be located away from the leg end, optimizing the overall motion performance of the system and improving the compactness and reliability of the mechanical structure. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the wheel leg with a planetary climbing structure described in this invention;

[0041] Figure 2 This is a schematic diagram of the internal structure of the calf support and the planetary flipping wheel mechanism described in this invention;

[0042] Figure 3 This is a cross-sectional schematic diagram of the planetary tilting wheel mechanism described in this invention;

[0043] Figure 4 This is a schematic diagram of the planetary secondary gear transmission system inside the triangular planetary transmission frame described in this invention;

[0044] Figure 5 This is a schematic diagram of the combined structure of the adjusting bolt structure, the synchronous belt tensioner, and the planetary secondary pulley synchronous belt described in this invention;

[0045] The markings in the diagram are as follows: 1. Torso structure; 2. Leg mechanism; 3. Planetary tilting wheel mechanism; 4. Hip joint motor; 5. Energy system; 6. Control system; 7. Thigh frame; 8. Knee joint motor; 9. Lower leg frame; 10. Planetary tilting motor; 11. Tilting active synchronous belt pulley; 12. Planetary tilting synchronous belt; 13. Tilting driven synchronous belt pulley; 14. Triangular planetary transmission frame; 15. Planetary secondary wheel; 16. Triangular planetary frame; 17. Planetary secondary wheel motor; 18. Planetary secondary wheel active synchronous belt pulley; 19. Planetary secondary wheel synchronous belt; 20. Synchronous belt tensioner; 21. Planetary secondary wheel driven synchronous belt pulley; 22. Adjusting bolt structure; 2201. Nut seat; 2202. Adjusting bolt; 2203. Tensioner frame. Detailed Implementation

[0046] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] It should be noted that all directional indicator terms such as "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" in the embodiments of this application indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. They are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0048] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0049] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0050] like Figures 1-4As shown, the wheel-like leg with a planetary climbing ladder structure includes a torso mechanism 1, a leg mechanism 2, and a planetary flipping wheel mechanism 3;

[0051] The torso mechanism 1 is movably connected to the leg mechanism 2;

[0052] The leg mechanism 2 is movably connected to the planetary tilting wheel mechanism 3;

[0053] The torso mechanism 1 is equipped with an energy system 5 and a control system 6. The energy system 5 is generally a rechargeable battery with a voltage specification of 48V DC. The control system 6 generally uses a microcontroller and controller devices. The control system 6 is existing technology and will not be described in detail here.

[0054] like Figure 1 As shown, in this embodiment, preferably, the leg mechanism 2 includes hip joint motors 4 disposed on both sides of the torso mechanism 1. The hip joint motors 4 are direct drive motors with a rated load of 40 N·m and a peak load of 120 N·m.

[0055] The output shaft of the hip joint motor 4 is provided with a thigh frame 7, which serves as a single-degree-of-freedom hip joint of the leg mechanism 2. The rotation speed of the single-degree-of-freedom hip joint does not exceed 50 rpm. It should be noted that there are two hip joint motors 4, one on the left and one on the right, and there are also two thigh frames 7, which are arranged symmetrically on the left and right.

[0056] The lower end of the thigh frame 7 is provided with a knee joint motor 8, which is a direct drive motor with a rated load of 40 N·m and a peak load of 120 N·m.

[0057] The knee joint motor 8 has a lower leg frame 9 on its output shaft, which serves as a single-degree-of-freedom knee joint of the leg mechanism 2. The rotation speed of the single-degree-of-freedom knee joint does not exceed 50 rpm.

[0058] like Figure 1 As shown, in this embodiment, in order to better arrange the leg mechanism 2 and the planetary flip wheel mechanism 3, the lower leg frame 9 is set inside the thigh frame 7.

[0059] like Figures 1-4 As shown, in this embodiment, preferably, the planetary tilting wheel mechanism 3 includes a planetary tilting motor 10, which is located in the upper middle part of the lower leg frame 9. The planetary tilting motor 10 is a direct drive motor with a rated load of 40 N·m and a peak load of 120 N·m.

[0060] The output shaft of the planetary tilting motor 10 extends through the side wall of the lower leg frame 9 into the interior, and a tilting active synchronous pulley 11 is provided on the output shaft of the planetary tilting motor 10.

[0061] The lower end of the calf frame 9 is provided with a rotating driven synchronous pulley 13 through a bearing and is connected to the rotating active synchronous pulley 11 through a planetary rotating synchronous belt 12.

[0062] The rotating driven synchronous pulley 13 is located at one end outside the lower leg frame 9 and is equipped with a triangular planetary transmission frame 14. The outline of the triangular transmission frame 14 is an arc shape rather than a straight line. The planetary rotating motor 10 drives the rotating active synchronous pulley 11 to rotate. The rotating active synchronous pulley 11 then drives the rotating driven synchronous pulley 13 to rotate through the planetary rotating synchronous belt 12. The power is transmitted to the rotating driven synchronous pulley 13 over a long distance through the planetary rotating synchronous belt 12. The rotating driven synchronous pulley 13 drives the triangular planetary transmission frame 14 to rotate.

[0063] The planetary secondary gear driven synchronous belt pulley 21 is hinged at the triangular end of the triangular part inside the triangular planetary transmission frame 14.

[0064] A triangular planetary gearbox 16 is provided on the outer side of the triangular planetary gearbox 14. At the triangular ends of the triangular planetary gearbox 16, a secondary planetary gear 15 is provided on the inner side of the triangular planetary gearbox 16 via a planetary gear shaft.

[0065] The three planetary secondary gears 15 are respectively connected to the three planetary secondary gear driven synchronous pulleys 21 for transmission;

[0066] The lower end of the calf frame 9 is provided with a planetary secondary gear motor 17. The output shaft of the planetary secondary gear motor 17 extends through the hollow hole inside the flip driven synchronous belt pulley 13 to the inside of the triangular planetary transmission frame 14.

[0067] The output shaft of the planetary secondary gear motor 17 is provided with a planetary secondary gear active synchronous pulley 18, which is located at the center inside the triangular planetary transmission frame 14.

[0068] A planetary secondary wheel synchronous belt 19 is provided between the planetary secondary wheel driving synchronous belt pulley 18 and the three planetary secondary wheel driven synchronous belt pulleys 21;

[0069] The planetary secondary gear synchronous belt 19 is connected to the planetary secondary gear driving synchronous belt pulley 18 and three planetary secondary gear driven synchronous belt pulleys 21 via multiple synchronous belt tensioners 20. There are six synchronous belt tensioners 20, which are used in pairs. The planetary secondary gear motor 17 drives the planetary secondary gear driving synchronous belt pulley 18 to rotate. The planetary secondary gear driving synchronous belt pulley 18 drives the three planetary secondary gear driven synchronous belt pulleys 21 to rotate through the planetary secondary gear synchronous belt 19, thereby driving the three planetary secondary gears 15 to rotate, realizing movement and ladder climbing. In addition, since the planetary secondary gear synchronous belt 19 adopts a tensioning method of tensioning the multiple synchronous belt tensioners 20 on the outside, that is, the multiple synchronous belt tensioners 20 are all located on the outside of the synchronous belt, the wrap angle of the planetary secondary gear synchronous belt 19 is increased, effectively preventing slippage or tooth skipping, and ensuring transmission stability.

[0070] like Figure 4 , Figure 5 As shown, in this embodiment, preferably, the number of the plurality of synchronous belt tensioners 20 is six;

[0071] They are evenly distributed in pairs on the outside of the planetary secondary gear active synchronous belt pulley 18, that is, they are evenly distributed in pairs along the circumferential direction of the planetary secondary gear active synchronous belt pulley 18 and are all located on the outside of the planetary secondary gear synchronous belt 19.

[0072] One synchronous belt tensioner 20 in each group is mounted on the side wall of the triangular planetary transmission frame 14 via a fixed shaft. This means the synchronous belt tensioner 20 will not move; it can only rotate freely around the fixed shaft. The other synchronous belt tensioner 20 in each group is mounted on the side wall of the triangular planetary transmission frame 14 via an adjusting bolt structure 22. Specifically, a nut seat 2201 is provided on the side wall of the triangular planetary transmission frame 14, corresponding to the synchronous belt tensioner 20. An adjusting bolt 2202 is fitted inside the nut seat 2201, and the end of the adjusting bolt 2202 is secured by a bearing. There is a tensioning pulley frame 2203. The synchronous belt tensioning pulley 20 is located inside the tensioning pulley frame 2203 via a rotating shaft and contacts the outer side of the planetary secondary synchronous belt 19. By turning the adjusting bolt 2202, the adjusting bolt 2202 moves along the nut seat 2201, causing the tensioning pulley frame 2203 to move away from or closer to the planetary secondary synchronous belt 19. This, in turn, causes the synchronous belt tensioning pulley 20 to move away from or closer to the planetary secondary synchronous belt 19, thereby achieving tension adjustment. In addition, since the end of the adjusting bolt 2202 is connected to the tensioning pulley frame 2203 via a bearing, the tensioning pulley frame 2203 will not rotate when the adjusting bolt 2202 is turned.

[0073] like Figure 2 , Figure 3As shown, in this embodiment, the planetary secondary gear active synchronous pulley 18 and the flip driven synchronous pulley 13 adopt a concentric shaft design. The hollow shaft of the planetary secondary gear active synchronous pulley 18 is sleeved inside the hollow shaft of the flip driven synchronous pulley 13, and the two are connected by bearings. The hollow shaft portion of the flip driven synchronous pulley 13 extends into the lower leg frame 9 and is fixed to the lower leg frame 9 by bearings. One end of the hollow shaft of the flip driven synchronous pulley 13 is fixed to the inner side wall of the triangular planetary transmission frame 14 by bolts. Through the synergistic optimization of the hollow shaft design and the synchronous belt drive, two motors are integrated into the same frame to achieve dual-degree-of-freedom transmission on a single shaft, effectively avoiding the wiring entanglement problem caused by the traditional dual-motor series connection. At the same time, thanks to the flexible layout of the synchronous belt drive, the flip joint motor can be far away from the end of the leg, optimizing the overall motion performance of the system and improving the compactness and reliability of the mechanical structure.

[0074] In this embodiment, preferably, both the reversing active synchronous belt 11 and the reversing driven synchronous belt pulley 13 have 44 teeth and a transmission ratio of 1:1.

[0075] The planetary reversing synchronous belt 12 type is 8M, with a bandwidth of 30 mm, a transmission pitch of 240 mm, and a belt length of 840 mm.

[0076] In this embodiment, preferably, the planetary secondary wheel 15 has a diameter of 230 mm and a width of 40 mm.

[0077] In this embodiment, preferably, both the planetary secondary gear driving synchronous pulley 18 and the planetary secondary gear driven synchronous pulley 21 have 32 teeth and a transmission ratio of 1:1; the planetary secondary gear synchronous belt 19 is a 14M belt type with a width of 30 mm and a belt length of 1988 mm.

[0078] In this embodiment, a wheeled-legged robot is also provided, including the wheeled-legged structure described in any of the above embodiments. This wheeled-legged robot has the ability to adapt to uneven terrain and adjust its overall height. It can achieve smooth and stable ladder climbing, has higher stability and motion efficiency, and has lower requirements for joint motors.

[0079] This invention provides a motion mode for a wheel-legged robot as follows:

[0080] I. Movement on flat ground: Due to the presence of the planetary secondary wheel synchronous belt 19 transmission system, all wheels in contact with the flat ground act as driving wheels. Therefore, the movement mode of this system can be referenced from a four-wheel drive vehicle. Since the hip joint in the wheel-leg structure of this system has only one degree of freedom, this system achieves movement through the differential speed of the planetary secondary wheels 15 of the two legs. Compared with the flat ground movement mode of traditional wheel-legged robots, this invention not only has the adaptability to uneven terrain and the ability to adjust the overall height, but also has stronger power, movement stability and movement efficiency.

[0081] II. In the climbing motion: This system achieves the smooth forward tilting of the system's center of gravity and the simultaneous flipping of the planetary flipping wheel mechanism 3 through the coupled motion of the leg mechanism 2 and the planetary flipping wheel mechanism 3, so as to promptly bring the secondary planetary wheel 15 into contact with the step; by repeating the above motion, smooth and stable climbing can be achieved. Compared with the traditional jumping climbing method of wheeled robots, it has higher stability and motion efficiency, and lower requirements for joint motors.

[0082] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A wheel-leg having a planetary ladder structure, characterized in that: The trunk mechanism (1), the leg mechanism (2) and the planetary flip wheel mechanism (3); The trunk mechanism (1) is movably connected with the leg mechanism (2); The leg mechanism (2) is movably connected with the planetary flip wheel mechanism (3); The trunk mechanism (1) is internally provided with an energy system (5) and a control system (6); The leg mechanism (2) comprises hip joint motors (4) arranged on both sides of the trunk mechanism (1); The output shaft of the hip joint motor (4) is provided with a thigh rack (7); The lower end of the thigh rack (7) is provided with a knee joint motor (8); The output shaft of the knee joint motor (8) is provided with a lower leg rack (9); The planetary flip wheel mechanism (3) comprises a planetary flip motor (10), and the planetary flip motor (10) is arranged at the middle upper portion of the lower leg rack (9); The output shaft of the planetary flip motor (10) extends to the inside through the side wall of the lower leg rack (9), and the output shaft of the planetary flip motor (10) is provided with a flip driving synchronous pulley (11); The lower end of the inside of the lower leg rack (9) is provided with a flip driven synchronous pulley (13) through a bearing and is in transmission connection with the flip driving synchronous pulley (11) through a planetary flip synchronous belt (12); The flip driven synchronous pulley (13) is provided with a triangular planetary transmission rack (14) at one end outside the lower leg rack (9); The triangular ends of the inside of the triangular planetary transmission rack (14) are all hinged with planetary secondary wheel driven synchronous pulleys (21); The outside of the triangular planetary transmission rack (14) is provided with a triangular planetary rack (16), and the triangular ends of the triangular planetary rack (16) are all provided with planetary secondary wheels (15) through planetary wheel shafts and located inside the triangular planetary rack (16); The three planetary secondary wheels (15) are in transmission connection with the three planetary secondary wheel driven synchronous pulleys (21) respectively; The lower end outside the lower leg rack (9) is provided with a planetary secondary wheel motor (17), and the output shaft of the planetary secondary wheel motor (17) extends to the inside of the triangular planetary transmission rack (14) through the hollow hole in the inside of the flip driven synchronous pulley (13); The output shaft of the planetary secondary wheel motor (17) is provided with a planetary secondary wheel driving synchronous pulley (18) and is located at the central position in the inside of the triangular planetary transmission rack (14); The planetary secondary wheel driving synchronous pulley (18) and the three planetary secondary wheel driven synchronous pulleys (21) are provided with a planetary secondary wheel synchronous belt (19); The planetary secondary wheel synchronous belt (19) is in meshing transmission connection with the planetary secondary wheel driving synchronous pulley (18) and the three planetary secondary wheel driven synchronous pulleys (21) through a plurality of synchronous belt tensioning pulleys (20); The number of the plurality of synchronous belt tensioning pulleys (20) is six; Two-by-two groups are evenly arranged outside the planetary secondary wheel driving synchronous pulley (18); One synchronous belt tensioning pulley (20) in each group is arranged on the side wall of the triangular planetary transmission rack (14) through a fixed shaft, and the other synchronous belt tensioning pulley (20) in each group is arranged on the side wall of the triangular planetary transmission rack (14) through an adjusting bolt structure (22).

2. The wheel-leg according to claim 1, having a planetary ladder structure, characterized in that: The calf frame (9) is arranged inside the thigh frame (7).

3. The wheel-legged robot having a planetary ladder structure according to claim 1, wherein; The planetary secondary wheel driving synchronous pulley (18) and the turnover driven synchronous pulley (13) adopt a concentric shaft design, the hollow shaft of the planetary secondary wheel driving synchronous pulley (18) is arranged inside the hollow shaft of the turnover driven synchronous pulley (13), and the two are connected through a bearing.

4. The wheel-leg according to claim 1, wherein: The number of teeth of the turnover driving synchronous pulley (11) and the turnover driven synchronous pulley (13) is 44, and the transmission ratio is 1:

1. The planetary turnover synchronous belt (12) adopts a 8M type, the belt width is 30 mm, the transmission spacing is 240 mm, and the belt length used is 840 mm.

5. The wheel-legged robot having a planetary ladder structure according to claim 1, characterized in that: The diameter of the planetary secondary wheel (15) is 230 mm, and the width is 40 mm.

6. The wheel-legged robot having a planetary ladder structure according to claim 1, characterized in that: The number of teeth of the planetary secondary wheel driving synchronous pulley (18) and the planetary secondary wheel driven synchronous pulley (21) is 32, and the transmission ratio is 1:1; the planetary secondary wheel synchronous belt (19) adopts a 14M type, the belt width is 30 mm, and the belt length used is 1988 mm.

7. A wheel-foot robot, characterized by: The foot-leg structure comprises the foot-leg structure according to any one of claims 1-6.

Images