Leg structure and humanoid robot

Abstract

The invention discloses a leg structure and a humanoid robot, relates to the technical field of humanoid robots, and aims at solving the problems that an existing leg structure is low in dynamic response speed and difficult in balance control. The leg structure provided by the invention comprises a thigh shell; the shank shell is provided with a first connecting end and a second connecting end which are oppositely arranged, and the first connecting end is close to the thigh shell relative to the second connecting end; the foot part is movably connected to the second connecting end; the first driving piece is arranged on the thigh shell; the first transmission assembly comprises a first connecting rod, a second connecting rod and a knee joint, the knee joint is rotationally connected with the thigh shell and the first connecting end, the first connecting rod is connected between the first driving piece and the knee joint, and the second connecting rod is connected between the knee joint and the foot. The dynamic response speed of the humanoid robot can be increased, and the balance control difficulty of the humanoid robot is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of humanoid robots, and in particular to a leg structure and a humanoid robot. Background Art

[0002] A humanoid robot is a multi-joint bionic robot that imitates human form and behavior. It imitates and expands human movements, interactions and environmental adaptability through the deep integration of bionic structures (such as bipedal walking mechanisms, humanoid limbs and dexterous hands), multimodal perception systems (visual, auditory, tactile and other sensors) and intelligent decision-making algorithms (artificial intelligence and motion control technology).

[0003] In related technologies, the leg structure of humanoid robots generally places the foot drive structure in the calf. This further increases the mass of the calf segment, which already bears the weight of the knee joint drive assembly. This not only requires greater torque to overcome the increased moment of inertia during robot control, affecting dynamic response speed, but also causes the robot's overall center of gravity to shift downward and become unevenly distributed, exacerbating center of gravity fluctuations during dynamic motion, increasing the difficulty of balance control, and even causing the risk of tipping. Summary of the Invention

[0004] The present application provides a leg structure and a humanoid robot, which can solve the problems of slow dynamic response speed and difficult balance control of existing leg structures.

[0005] To achieve the above objectives, in a first aspect, the leg structure provided by the present application includes: Thigh shell; The calf shell has a first connecting end and a second connecting end opposite to each other, wherein the first connecting end is arranged closer to the thigh shell than the second connecting end; a foot portion movably connected to the second connection end; a first driving member, disposed on the thigh housing; The first transmission assembly includes a first connecting rod, a second connecting rod and a knee joint. The knee joint is rotatably connected to the thigh shell and the first connecting end. The first connecting rod is connected between the first driving member and the knee joint, and the second connecting rod is connected between the knee joint and the foot.

[0006] In some embodiments of the present application, the first transmission assembly further includes a first pivot member, which rotatably connects the thigh shell, the first connecting end, and the knee joint.

[0007] In some embodiments of the present application, the connection lines between the connection point between the knee joint and the first pivot member, the connection point between the knee joint and the first connecting rod, and the connection point between the knee joint and the second connecting rod are triangular structures.

[0008] In some embodiments of the present application, the knee joint includes a first plate portion and a second plate portion that are detachably connected, and at least one of the first plate portion and the second plate portion is respectively provided with a first notch and a second notch on a side facing the other, an end of the first connecting rod away from the first driving member extends into the first notch and is rotatably connected to the first plate portion and the second plate portion, and an end of the second connecting rod away from the foot extends into the second notch and is rotatably connected to the first plate portion and the second plate portion.

[0009] In some embodiments of the present application, a pair of thigh connecting ears extending toward the calf shell are provided on the thigh shell, a pair of calf connecting ears are provided at the first connecting end, the pair of calf connecting ears are provided in the gap between the pair of thigh connecting ears, the knee joint is provided in the gap between the pair of calf connecting ears, and is rotatably connected to each calf connecting ear and each thigh connecting ear.

[0010] In some embodiments of the present application, the thigh shell includes a first side portion and a second side portion that are connected, the first driving members have two and are respectively arranged on the first side portion and the second side portion, and the output shafts of the two first driving members are coaxially arranged; the first transmission assemblies have two and are both movably connected to the foot, and the first driving members and the first transmission assemblies are arranged one-to-one.

[0011] In some embodiments of the present application, the second connecting rod in each first transmission assembly and the knee joint are rotationally connected via a ball joint.

[0012] In some embodiments of the present application, the leg structure further comprises: The first rotating mechanism includes a first mounting seat and a foot cross shaft. The first mounting seat is fixedly mounted on the foot. The foot cross shaft includes a first shaft body and a second shaft body that are perpendicular to each other. The first shaft body is connected to the first mounting seat. The second shaft body has two and is respectively arranged on the first shaft body and located opposite to the first mounting seat. The two first shaft bodies are respectively rotatably connected to the two second connecting rods in the two first transmission assemblies.

[0013] In some embodiments of the present application, the leg structure further comprises: The second rotating mechanism is used to rotationally connect the calf shell and the rear end of the foot. The second rotating mechanism includes a second mounting seat and an ankle cross axis. The ankle cross axis includes a third axis and a fourth axis that are perpendicular to each other. The third axis is fixedly mounted on the rear end of the foot through the second mounting seat, and the fourth axis is rotationally connected to the calf shell.

[0014] In some embodiments of the present application, the calf shell includes a first cover plate and a second cover plate connected to each other, the second rotating mechanism is arranged between the first cover plate and the second cover plate, the fourth axis passes through the third axis, and the two ends of the fourth axis are respectively rotatably connected to the first cover plate and the second cover plate.

[0015] In some embodiments of the present application, the leg structure further comprises: A second driving member is provided on the thigh housing and is located at an end of the thigh housing away from the calf housing; a second transmission assembly, transmittingly connecting the second driving member and the calf housing; The first driving member is arranged on a side of the second driving member close to the calf shell, and has a distance between it and an end of the thigh shell close to the calf shell.

[0016] In a second aspect, the present application also provides a humanoid robot comprising a leg structure as described in any of the above technical solutions.

[0017] The above technical solution of this application has at least the following beneficial effects: This application places the first drive element directly on the thigh housing, transferring the mass of the foot drive assembly, originally borne by the calf, to the thigh segment. This significantly reduces the mass of the calf segment, lowering the torque required during control and improving the robot's dynamic response speed, making it particularly agile during movements like rapid walking and turning. Furthermore, because the thigh segment is closer to the robot's overall center of mass (typically located in the middle of the torso), the center of gravity is closer to the robot's torso, reducing center of gravity fluctuations during dynamic motion, making balance control easier and minimizing the risk of tipping. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 is a three-dimensional diagram of the leg structure in an embodiment of the present application; Figure 2 This is one of the cross-sectional views of the leg structure in the embodiment of the present application; Figure 3 yes Figure 2 A magnified view of part A in FIG; Figure 4 yes Figure 1 A magnified view of part B in FIG; Figure 5 This is the second cross-sectional view of the leg structure in the embodiment of the present application; Figure 6 yes Figure 5 Enlarged view of part C in ; Figure 7 yes Figure 1 Enlarged view of part D in .

[0020] Description of reference numerals: 1-thigh shell; 11-thigh connecting ear; 12-first side; 13-second side; 2-calf shell; 21-first connecting end; 22-second connecting end; 23-calf connecting ear; 24-first cover plate; 25-second cover plate; 3-foot; 31-front end; 32-rear end; 4-first driving member; 5-first transmission assembly; 51-first connecting rod; 52-second connecting rod; 53-knee joint; 531-first plate; 532-second plate; 533- First notch; 534-second notch; 54-first pivot member; 55-connecting crank; 6-first rotating mechanism; 61-first mounting seat; 62-foot cross axis; 621-first axis; 622-second axis; 7-second rotating mechanism; 71-second mounting seat; 72-ankle cross axis; 721-third axis; 722-fourth axis; 8-second driving member; 9-second transmission assembly; 91-calf connecting rod; 92-calf crank; 93-calf rotating shaft. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0022] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0023] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0025] The present application provides a leg structure and a humanoid robot, which are described in detail below. It should be noted that the order of description of the following embodiments does not limit the preferred order of the embodiments of the present application. In addition, in the following embodiments, the description of each embodiment has its own focus. For parts not described in detail in one embodiment, please refer to the relevant description of other embodiments.

[0026] Please refer to Figure 1 and Figure 2 The leg structure includes a thigh shell 1, a calf shell 2, a foot 3, a first driving member 4 and a first transmission assembly 5. The calf shell 2 has a first connecting end 21 and a second connecting end 22 arranged opposite to each other, and the first connecting end 21 is arranged close to the thigh shell 1 relative to the second connecting end 22. The foot 3 is movably connected to the second connecting end 22. The first driving member 4 is arranged on the thigh shell 1, and the first transmission assembly 5 includes a first connecting rod 51, a second connecting rod 52 and a knee joint 53. The knee joint 53 is rotatably connected to the bottom end of the thigh shell 1 and the first connecting end 21. The first connecting rod 51 is connected between the first driving member 4 and the knee joint 53, and the second connecting rod 52 is connected between the knee joint 53 and the foot 3.

[0027] The present application sets the first drive member 4 directly on the thigh shell 1, so that the mass of the foot 3 drive component that was originally required to be carried by the calf is transferred to the thigh segment. The mass of the calf segment is significantly reduced, the torque required during the control process is reduced, and the dynamic response speed of the robot is improved, especially in actions such as fast walking and turning. Specifically, the lightweighting of the lower limb end reduces the total mass that needs to be driven by the first drive member 4, thereby reducing the load and moment of inertia of the first drive member 4, improving energy efficiency and dynamic response speed. At the same time, because the thigh segment is closer to the overall center of mass of the robot (usually located in the middle of the torso), the center of gravity distribution is closer to the torso of the robot, the center of gravity fluctuation amplitude is reduced during dynamic movement, the difficulty of balance control is reduced, and the risk of tipping is reduced.

[0028] Furthermore, the knee joint 53 is connected to the bottom end of the thigh shell 1 and the first connection end 21 at the same time. It not only participates in the flexion and extension movement of the knee joint 53, but also serves as an intermediate conversion component for the transmission of the foot 3, thereby achieving coordinated movement of the knee joint 53 and the foot 3, which is closer to the biological movement pattern. The series connection of the first link 51 and the second link 52 allows the movement path of the foot 3 (such as dorsiflexion / plantar flexion, inversion / valgus) to be decoupled from the movement of the knee joint 53, avoiding the limitation of the ankle joint's freedom of movement by a single drive source. In addition, the first drive member 4 is arranged on the thigh shell 1, so that only the lightweight second link 52 needs to be arranged inside the calf shell 2, reducing the problem of component crowding and providing more space for heat dissipation design (such as ventilation channels) and cable layout.

[0029] Exemplarily, the first connecting rod 51 extends in roughly the same direction as the thigh shell 1, and the second connecting rod 52 extends in roughly the same direction as the calf shell 2, so as to avoid lateral expansion from occupying additional space, reduce space occupancy, and make the structure of the entire leg structure more compact. Among them, the knee joint 53 itself is a double-joint component that simultaneously connects the bottom end of the thigh shell 1 and the first connecting end 21 of the calf shell 2. When the first connecting rod 51 extends in roughly the same direction as the thigh shell 1, the force generated by the first driving member 4 can be directly transmitted to the knee joint 53 through the first connecting rod 51, reducing the force decomposition loss caused by angular deviation, making the movement of the knee joint 53 more precise and efficient. That is, when the first driving member 4 outputs the driving force, the planar motion of the first connecting rod 51 is accurately converted into the fixed-axis rotation of the knee joint 53 through the axial constraint of the first pivot member 54. The second connecting rod 52 extends in roughly the same direction as the calf shell 2, and can drive the foot 3 more directly, avoiding unnecessary motion conversion steps, thereby reducing mechanical energy consumption and improving response speed.

[0030] In some embodiments, the first transmission assembly 5 also includes a first pivot member 54, which simultaneously rotates and connects the bottom end of the thigh shell 1, the first connecting end 21 and the knee joint 53 to reduce the number of parts and assembly complexity. The first pivot member 54 rigidly connects the bottom end of the thigh shell 1, the first connecting end 21 and the knee joint 53 on the same rotation axis, so that the transmission related to the driving of the knee joint 53 and the foot 3 can be synchronized based on the same rotation reference. For example, when the first driving member 4 pushes the knee joint 53 to rotate through the first connecting rod 51, the rotation of the knee joint 53 will directly drive the first connecting end 21 and the foot 3 to rotate synchronously through the second connecting rod 52, thereby ensuring that the movement of the knee joint 53 and the foot 3 is coordinated and consistent. Exemplarily, the first pivot member 54 is a first pivot shaft, which is simultaneously provided through the bottom end of the thigh shell 1, the first connecting end 21 and the knee joint 53.

[0031] In addition, the first transmission assembly 5 also includes a connecting crank 55, which is disposed within the thigh housing 1 and is used to transmit and connect the first drive member 4 and the first connecting rod 51. As an intermediate transmission component, the connecting crank 55 can adjust the torque by adjusting the crank arm length. Its geometric structure (such as eccentric arrangement or asymmetric arm length) can decompose the rotational motion of the drive member into multi-directional component forces, and convert them into the required swing angles of the first connecting rod 51, achieving a more flexible torque transmission path.

[0032] Please combine Figure 2 and Figure 3 In this embodiment, the lines connecting the knee joint 53 and the first pivot member 54, the knee joint 53 and the first connecting rod 51, and the knee joint 53 and the second connecting rod 52 form a triangular structure. In mechanical theory, a triangle is the most stable geometric shape within a plane and can effectively resist deformation caused by external forces. When the knee joint 53 is in motion, this triangular structure can effectively distribute the load, effectively avoiding the problem of excessive local stress concentration, and significantly reducing the possibility of component deformation or damage.

[0033] Especially in scenarios where dynamic loads are applied, such as the impact forces generated by walking or running, the triangular layout can significantly enhance the rigidity of the knee joint 53, ensuring the accuracy and stability of its movement. In addition, from a mechanical point of view, the force can be more evenly distributed between the three connection points of the triangle, rather than being concentrated on individual points. This significantly reduces the stress borne by the knee joint 53 and the first pivot member 54, first connecting rod 51, and second connecting rod 52 connected thereto. Reduced stress concentration means a lower risk of wear and fatigue fracture, which helps to increase the service life of the ankle drive structure and reduce maintenance times and costs.

[0034] Please continue to refer to Figure 3In this embodiment, the knee joint 53 includes a first plate portion 531 and a second plate portion 532 that are detachably connected. A first notch 533 and a second notch 534 are respectively provided on the side of at least one of the first plate portion 531 and the second plate portion 532 that faces the other. The end of the first connecting rod 51 that is distal to the first driving member 4 extends into the first notch 533 and is rotationally connected to the first and second plate portions 531 and 532. The end of the second connecting rod 52 that is distal to the foot portion 3 extends into the second notch 534 and is rotationally connected to the first and second plate portions 531 and 532. Specifically, when the first connecting rod 51 extends into the first notch 533 and the second connecting rod 52 extends into the second notch 534, the first notch 533 (the second notch 534) provides a retaining cavity for the first connecting rod 51 (the second connecting rod 52). When the first connecting rod 51 (the second connecting rod 52) rotates around the knee joint 53, the inner wall of the first notch 533 (the second notch 534) will form a lateral constraint on the first connecting rod 51 (the second connecting rod 52), limiting the movement and shaking of the first connecting rod 51 (the second connecting rod 52) in the direction perpendicular to the rotation axis, so that the motion trajectory of the first connecting rod 51 (the second connecting rod 52) is more in line with the designed circular motion law, reducing the transmission error caused by the deviation of the first connecting rod 51 (the second connecting rod 52).

[0035] During the specific assembly process, the first plate portion 531 and the second plate portion 532 can be manufactured separately, and then the first connecting rod 51 and the second connecting rod 52 can be rotationally connected to the first plate portion 531 respectively. The second plate portion 532 can then be fixedly connected to the first plate portion 531, and the first connecting rod 51 and the second connecting rod 52 can be rotationally connected to the second plate portion 532 at the same time, thereby significantly improving assembly efficiency and being particularly suitable for mass production or on-site maintenance scenarios. It should be noted that for the embodiment in which the knee joint 53 includes a detachably connected first plate portion 531 and a second plate portion 532, the first pivot member 54 (first pivot axis) simultaneously rotationally connects the bottom end, the first connecting end 21, the first plate portion 531, and the second plate portion 532. That is, the bottom end, the first connecting end 21, the first plate portion 531, and the second plate portion 532 are all provided with through-holes with overlapping axes for the first pivot member 54 to pass through.

[0036] For example, the first plate portion 531 and the second plate portion 532 are each provided with a first notch 533 and a second notch 534 on the facing sides thereof. The first plate portion 531 and the second plate portion 532 are symmetrically arranged about the central symmetry plane of the knee joint 53. When force is transmitted from the first connecting rod 51 and the second connecting rod 52 to the knee joint 53, the first plate portion 531 and the second plate portion 532 bear substantially the same load, thereby ensuring that the knee joint 53 maintains dynamic balance during rotation and reducing vibration and deflection. In other words, the first notch 533 on the first plate portion 531 is recessed in a direction away from the second plate portion 532, and the first notch 533 on the second plate portion 532 is recessed in a direction away from the first plate portion 531. The recessed depth of the first notch 533 on the first plate portion 531 is equal to the recessed depth of the first notch 533 on the second plate portion 532.

[0037] Please combine Figure 1 and Figure 4 The thigh shell 1 is provided with a pair of thigh connecting ears 11 extending toward the calf shell 2. The first connecting end 21 is provided with a pair of calf connecting ears 23. The pair of calf connecting ears 23 are arranged in the gap between the pair of thigh connecting ears 11. The knee joint 53 is arranged in the gap between the pair of calf connecting ears 23 and is rotationally connected to each calf connecting ear 23 and each thigh connecting ear 11. The nested layout of the thigh connecting ears 11 and the calf connecting ears 23 places the knee joint 53 in the middle area between the two layers of connecting ears, which is equivalent to forming mechanical support arms on both sides of the knee joint 53, reducing the bending stress of the knee joint 53. At the same time, the nested structure forms a multi-rigid body coupling system by increasing the number of connection points (two connection points for the thigh connecting ears 11, two connection points for the calf connecting ears 23, and one connection point for the knee joint 53). This can effectively absorb and attenuate impact energy during the flexion and extension of the knee joint 53.

[0038] Please also refer to Figure 1 、 Figure 2 and Figure 5In this embodiment, the thigh housing 1 includes a first side portion 12 and a second side portion 13 connected to each other. Two first drive members 4 are provided, one on each of the first and second side portions 12, 13, with the output shafts of the two first drive members 4 coaxially arranged. Two first transmission assemblies 5 are provided, each movably connected to the foot 3. The first drive members 4 correspond to each other in a one-to-one relationship. The actual movement of the foot 3 includes two degrees of freedom: plantar flexion / dorsiflexion (forward and backward swinging) and inversion / eversion (left and right tilting). The two first drive members 4 are movably connected to the foot 3 via their respective first transmission assemblies 5 to control these two degrees of freedom, enabling more accurate replication of the complex movement patterns of the human ankle joint. Specifically, when the second connecting rods 52 in the two first transmission assemblies 5 move in the same direction, the front end 31 of the foot 3 can swing up and down. When the second connecting rods 52 in the two first transmission assemblies 5 move in opposite directions, a combined left-right and up-and-down swinging motion of the front end 31 of the foot 3 can be achieved.

[0039] The two first drive members 4 are positioned on opposite sides of the first side portion 12 and the second side portion 13, respectively. That is, both first drive members 4 are positioned outside the thigh housing 1, exposing them to a more open air environment. This helps improve the heat dissipation efficiency of the first drive members 4, avoids performance degradation or component damage due to overheating, and enhances long-term operational reliability. Furthermore, if a first drive member 4 malfunctions, it can be directly removed from the outside of the thigh housing 1 for repair or replacement, significantly reducing maintenance time.

[0040] In some embodiments, the second connecting rod 52 and the knee joint 53 in each first transmission assembly 5 are rotatably connected via a ball joint. This ball joint allows the connecting rod to rotate freely in three mutually perpendicular directions (e.g., flexion and extension, left and right swing, and internal and external rotation), accurately replicating the complex trajectory of the knee joint 53 during movements such as walking, running, and climbing stairs. For example, during the movement of the foot 3, the knee joint 53 may need to simultaneously flex and extend, and slightly internally rotate to adjust to a tilted surface. The ball joint naturally accommodates these multi-directional motion requirements, avoiding mechanical jamming or wear caused by forced constraints.

[0041] The ball joint's ball and socket structure distributes loads across multiple contact surfaces, breaking down forces concentrated on a single axis into distributed forces along different directions, significantly reducing local stress peaks. For example, when the knee joint 53 is subjected to a lateral impact, the ball joint can transfer the force to the annular contact surface of the ball socket through a slight swing of the ball joint, rather than concentrating it at a single hinge point, thereby reducing the risk of fatigue damage. For example, a ball and socket structure can be formed at the end of the second connecting rod 52, and a ball joint can be formed on the shaft that rotatably connects the second connecting rod 52 and the knee joint 53.

[0042] Please refer to Figure 5 、 Figure 6 and Figure 7 The leg structure also includes a first rotating mechanism 6, which includes a first mounting seat 61 and a foot cross shaft 62. The first mounting seat 61 is fixedly mounted on the foot 3, and the foot cross shaft 62 includes a first shaft body 621 and a second shaft body 622 that are perpendicular to each other. The first shaft body 621 is connected to the first mounting seat 61, and there are two second shaft bodies 622, which are respectively arranged on the first shaft body 621 and located opposite to the first mounting seat 61. The two first shaft bodies 621 are respectively rotatably connected to the two second connecting rods 52 in the two first transmission assemblies 5, so as to constrain the negative degree of freedom introduced by the ball joint through the foot cross shaft 62, thereby eliminating the hidden danger of shaking of the foot 3.

[0043] Specifically, since the second connecting rod 52 of each first transmission assembly 5 is connected to the knee joint 53 by a ball joint, the foot 3 can be given flexible flexion, extension, rotation and side swing capabilities, but it also introduces two unexpected negative degrees of freedom, which may cause the foot 3 to shake or deflect unexpectedly during movement. As a result, the two second shafts 622 of the foot cross shaft 62 are respectively connected to the two second connecting rods 52. The constraint system formed by the mutually perpendicular first shaft 621 and second shaft 622 accurately limits the two negative degrees of freedom introduced by the ball joint, thereby retaining the original multi-directional movement flexibility of the ball joint and eliminating redundant shaking through the physical limitation of the foot cross shaft 62, ensuring the accuracy and stability of the movement of the foot 3. It should be noted that the upper and lower parts of the above-mentioned calf shell 2 are provided with openings for the two ends of the second connecting rod 52 to pass through the corresponding openings and connect to the knee joint 53 and the first rotating mechanism 6 respectively.

[0044] Please refer to Figure 2 、 Figure 5 and Figure 6 The leg structure further includes a second rotating mechanism 7, which rotates the rear end 32 (see reference numerals) connecting the calf housing 2 and the foot 3. Figure 2), the second rotation mechanism 7 includes a second mounting base 71 and an ankle cross axis 72. The ankle cross axis 72 includes a third axis 721 and a fourth axis 722 that are perpendicular to each other. The third axis 721 is fixedly mounted on the rear end 32 of the foot 3 via the second mounting base 71, and the fourth axis 722 is rotationally connected to the calf shell 2. Specifically, the ankle cross axis 72 in the second rotation mechanism 7 includes a third axis 721 and a fourth axis 722 that are perpendicular to each other. This structure provides two mutually perpendicular rotational degrees of freedom between the calf shell 2 and the rear end 32 of the foot 3. These two degrees of freedom can accurately simulate the multi-directional movement of the human ankle joint. For example, the third axis 721 can be used to achieve inversion and eversion of the foot 3 in the coronal plane, as well as a certain degree of rotational adjustment; the fourth axis 722 can be used to achieve flexion and extension of the foot 3 in the sagittal plane, similar to the dorsiflexion and plantar flexion of the human ankle joint. The two mutually perpendicular rotational degrees of freedom provided by the ankle cross axis 72 enable the foot 3 to flexibly adjust its posture in multiple directions to adapt to different movement requirements and terrain changes, making the movement of the entire leg structure more stable and smooth, and improving the efficiency and quality of movement.

[0045] Exemplarily, the calf shell 2 includes a first cover plate 24 and a second cover plate 25 connected to each other, the second rotation mechanism 7 is arranged between the first cover plate 24 and the second cover plate 25, the fourth shaft 722 is passed through the third shaft 721, and the two ends of the fourth shaft 722 extend out of the third shaft 721 and are rotationally connected to the first cover plate 24 and the second cover plate 25. That is, the second rotation mechanism 7 is built into the closed space between the first cover plate 24 and the second cover plate 25, making the overall structure of the calf shell 2 more compact. The connection between the first cover plate 24 and the second cover plate 25 forms a closed shell unit, which completely encloses the ankle cross axis 72 and forms a whole with unified mechanical properties with the main structure of the calf shell 2, thereby enhancing the rigidity of the local structure and reducing the risk of loose connection or vibration caused by decentralized installation.

[0046] It is understood that the ends of the fourth shaft 722 are pivotally connected to the first cover plate 24 and the second cover plate 25, respectively, effectively adding two rigid support points to the exterior of the ankle cross shaft 72. When the foot 3 is subjected to lateral or rotational forces, the fourth shaft 722, connected via the cover plates, forms a stable pivot point, limiting unintended deviation or wobble of the shaft and improving the rigidity and positioning accuracy of the pivotal connection.

[0047] Please continue to refer to Figure 1 and Figure 2The leg structure also includes a second drive member 8 and a second transmission assembly 9. The second drive member 8 is mounted on the thigh shell 1, at the end of the thigh shell 1 facing away from the calf shell 2. The second transmission assembly 9 provides a transmission connection between the second drive member 8 and the calf shell 2. The first drive member 4 is located on the side of the second drive member 8 closest to the calf shell 2, with a gap between it and the end of the thigh shell 1 facing the calf shell 2. The second drive member 8 is located at the end of the thigh shell 1 facing away from the calf shell 2 (i.e., near the hip joint). As the core component that provides the swinging power for the calf shell 2, it is installed away from the center of mass of the calf shell 2. Power is remotely transmitted to the calf shell 2 via the second transmission assembly 9 (e.g., a connecting rod, gear set, or cable mechanism). This prevents the mass of the second drive member 8 from being directly added to the lower limb, thus reducing the mass burden on the lower limb. As a result, the calf shell 2 and foot 3 must overcome a smaller moment of inertia during swinging. The second drive member 8 only needs to output lower torque to achieve rapid movement switching, thereby improving movement speed and flexibility.

[0048] Similarly, the second driving member 8 is also arranged on the outside of the thigh shell 1, and has the same technical effect as the first driving member 4 arranged on the outside of the thigh shell 1, which will not be repeated in this application.

[0049] like Figure 2 and Figure 3 As shown, the second transmission assembly 9 includes a shank connecting rod 91, a shank crank 92 and a shank rotating shaft 93, wherein the shank crank 92 is arranged at the output end of the second driving member 8, the first end of the shank connecting rod 91 is rotationally connected to the shank crank 92, and the other end is rotationally connected to the shank rotating shaft 93, one end of the shank rotating shaft 93 is connected to the first side portion 12 of the thigh shell 1, and the other end is connected to the second side portion 13 of the thigh shell 1. The second driving member 8 usually outputs a rotational motion (such as the circular rotation of the motor), while the shank shell 2 needs to achieve a swinging motion (such as swinging back and forth to simulate the shank movement when walking). The shank crank 92 converts the rotation input of the driving member into its own swing (or rotation of a specific trajectory), and then transmits this swing to the shank rotating shaft 93 through the shank connecting rod 91, finally achieving the swinging motion of the shank shell 2. According to specific usage requirements, the amplitude, speed and rhythm of the calf shell 2 swing can be accurately controlled by adjusting the length of the calf crank 92, the length of the calf connecting rod 91 and the connection angle of each component, thereby achieving a movement pattern that is highly matched with the natural gait of the human body.

[0050] In some embodiments of the present application, the present application further provides a humanoid robot comprising the leg structure described in any of the above embodiments. Since the leg structure of the humanoid robot and the above leg structure have the same technical features, they can solve the same technical problems and achieve the same technical effects.

[0051] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0052] The above is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims. In addition, the specification uses specific examples to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core ideas of the present application. The content of this specification should not be understood as limiting the present application.

Claims

1. A leg structure, characterized in that: include: Thigh shell; The calf shell has a first connecting end and a second connecting end opposite to each other, wherein the first connecting end is arranged closer to the thigh shell relative to the second connecting end; a foot, movably connected to the second connection end; a first driving member, disposed on the thigh housing; The first transmission assembly includes a first connecting rod, a second connecting rod and a knee joint, wherein the knee joint is rotationally connected to the thigh shell and the first connecting end, the first connecting rod is connected between the first driving member and the knee joint, and the second connecting rod is connected between the knee joint and the foot.

2. The leg structure according to claim 1, characterized in that: The first transmission assembly further includes a first pivoting member, which is rotatably connected to the thigh shell, the first connecting end and the knee joint.

3. The leg structure according to claim 2, characterized in that: A figure formed by connecting lines between the connection point between the knee joint and the first pivot member, the connection point between the knee joint and the first connecting rod, and the connection point between the knee joint and the second connecting rod is a triangle.

4. The leg structure according to claim 2, characterized in that: The knee joint includes a first plate portion and a second plate portion that are detachably connected, and a first notch and a second notch are respectively provided on a side of at least one of the first plate portion and the second plate portion facing the other, an end of the first connecting rod away from the first driving member extends into the first notch and is rotatably connected to the first plate portion and the second plate portion, and an end of the second connecting rod away from the foot extends into the second notch and is rotatably connected to the first plate portion and the second plate portion.

5. The leg structure according to claim 1, characterized in that: The thigh shell is provided with a pair of thigh connecting ears extending toward the calf shell, the first connecting end is provided with a pair of calf connecting ears, the pair of calf connecting ears are arranged in the interval between the pair of thigh connecting ears, the knee joint is arranged in the interval between the pair of calf connecting ears, and is rotatably connected with each of the calf connecting ears and each thigh connecting ear.

6. The leg structure according to any one of claims 1 to 5, characterized in that: The thigh housing includes a first side portion and a second side portion connected to each other, the first driving members have two and are respectively arranged on the first side portion and the second side portion, and the output shafts of the two first driving members are coaxially arranged; There are two first transmission components, both of which are movably connected to the foot, and the first driving members are arranged in a one-to-one correspondence with the first transmission components.

7. The leg structure according to claim 6, characterized in that: The second connecting rod in each of the first transmission assemblies and the knee joint are rotationally connected via a ball joint.

8. The leg structure according to claim 7, characterized in that: The leg structure further comprises: The first rotating mechanism includes a first mounting seat and a foot cross shaft. The first mounting seat is fixedly mounted on the foot. The foot cross shaft includes a first shaft body and a second shaft body that are perpendicular to each other. The first shaft body is connected to the first mounting seat. There are two second shaft bodies, which are respectively arranged on the first shaft body and located opposite to the first mounting seat. The two first shaft bodies are respectively rotatably connected to the two second connecting rods in the two first transmission assemblies.

9. The leg structure according to claim 8, characterized in that: The leg structure further comprises: A second rotating mechanism rotationally connects the calf shell and the rear end of the foot. The second rotating mechanism includes a second mounting seat and an ankle cross axis. The ankle cross axis includes a third axis and a fourth axis that are perpendicular to each other. The third axis is fixedly mounted on the rear end of the foot through the second mounting seat. The fourth axis is rotationally connected to the calf shell.

10. The leg structure according to claim 9, characterized in that: The calf shell includes a first cover plate and a second cover plate connected to each other, the second rotating mechanism is arranged between the first cover plate and the second cover plate, the fourth shaft body passes through the third shaft body, and the two ends of the fourth shaft body are respectively rotatably connected to the first cover plate and the second cover plate.

11. The leg structure according to claim 1, characterized in that: The leg structure further comprises: A second driving member is provided on the thigh housing and is located at an end of the thigh housing away from the calf housing; a second transmission assembly, transmittingly connecting the second driving member and the calf housing; Wherein, the first driving member is arranged on a side of the second driving member close to the calf shell, and has a distance between it and an end of the thigh shell close to the calf shell.

12. A humanoid robot, characterized in that: Comprising the leg structure according to any one of claims 1 to 11.

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