Humanoid robot leg structure assembly and humanoid robot

Abstract

The present invention belongs to the field of robotics-related technologies and discloses a humanoid robot leg structure assembly and a humanoid robot. The leg structure assembly includes: a hip joint assembly including three drive modules to achieve three-degree-of-freedom rotational motion similar to that of a human hip; a knee joint assembly including a knee joint structure, a knee joint drive module, and a knee joint transmission assembly. The knee joint drive module is mounted at the upper end of the thigh structure and drives the calf structure to achieve flexion and extension through the knee joint transmission assembly; and an ankle joint assembly including an ankle joint structure, an ankle joint drive module, and an ankle joint transmission assembly. The ankle joint drive module is mounted at the upper end of the thigh structure and below the knee joint drive module. The ankle joint drive module drives the foot structure to achieve plantar flexion / dorsiflexion and eversion / adduction motion through the ankle joint transmission assembly. The present invention moves the drive module upward to the upper end of the thigh structure, resulting in no drive module at the end, centralized mass, and low moment of inertia, which is beneficial for increasing the movement frequency of the humanoid robot.

Description

Technical Field

[0001] The present invention belongs to the technical field related to robots, and more specifically, relates to a leg structure assembly of a humanoid robot and the humanoid robot. Background Art

[0002] Humanoid robots have long been a hot research topic, and creating autonomous machines that resemble humans has always been the ultimate goal of researchers. As the technology matures, researchers are exploring the enormous potential of humanoid robots as general-purpose automated equipment to replace factory workers, and significant resources are being invested in their development. This is because humanoid robots can seamlessly integrate into workflows and collaborate with human workers, unlike other automated equipment that requires specialized design environments and tools. This gives humanoid robots greater application value.

[0003] Currently, humanoid robot drive modules, such as motors and hydraulic components, still struggle to achieve the torque-to-weight ratio of human muscle output. Furthermore, the lightweight and strength of humanoid robot structural components cannot match those of human leg bones, limiting the frequency of movement of humanoid robot legs and preventing them from swinging at high frequencies. Furthermore, existing humanoid robot leg structures also suffer from complex structures, numerous parts, and complex assembly and maintenance.

[0004] Most existing robots, such as Japan's ASIMO robot, achieve humanoid locomotion by placing drive modules in situ within the leg joints to enable rotation of the thigh, calf, and foot. However, existing robot leg structures often suffer from high rotational inertia during humanoid locomotion, limiting movement frequency. Summary of the Invention

[0005] In response to the above defects or improvement needs of the prior art, the present invention provides a humanoid robot leg structure assembly and a humanoid robot, which are used to solve the problem that the existing robot leg structure usually has high rotational inertia during humanoid movement and limits the movement frequency.

[0006] To achieve the above objectives, according to one aspect of the present invention, a leg structure assembly of a humanoid robot is provided, comprising a hip joint assembly, a thigh structure, a knee joint assembly, a calf structure, an ankle joint assembly, and a foot structure;

[0007] The hip joint assembly includes three drive modules for realizing three-degree-of-freedom rotational motion of a human-like hip joint, and the output end drive module of the hip joint assembly is installed at the upper end of the thigh structure;

[0008] The knee joint assembly includes a knee joint structure, a knee joint drive module, and a knee joint transmission assembly. The lower end of the thigh structure is rotatably connected to the upper end of the shank structure via the knee joint structure to provide the shank structure with a degree of freedom of flexion / extension movement. The knee joint drive module is mounted on the upper end of the thigh structure and is connected to the shank structure via the knee joint transmission assembly, so as to drive the shank structure to achieve flexion / extension movement via the knee joint transmission assembly.

[0009] The ankle joint assembly includes an ankle joint structure, an ankle joint drive module and an ankle joint transmission component. The ankle joint structure includes a cross-axis structure. The lower end of the calf structure is rotatably connected to the foot structure through the cross-axis structure to provide the foot structure with plantar flexion / dorsiflexion movement freedom and eversion / adduction movement freedom. The ankle joint drive module is installed at the upper end of the thigh structure and is located below the knee joint drive module. The ankle joint drive module is connected to the foot structure through the ankle joint transmission component, and is used to drive the foot structure to achieve plantar flexion / dorsiflexion movement and eversion / adduction movement through the ankle joint transmission component.

[0010] According to the leg structure assembly of the humanoid robot provided by the present invention, the hip joint assembly includes a rotation drive module, a rotation-side swing connection plate, a side swing drive module, a side swing-flexion and extension connection plate, and a flexion and extension drive module; wherein the housing of the rotation drive module is used to be fixed to the pelvis of the humanoid robot, and the output end flange is fixed to the rotation-side swing connection plate; the housing of the side swing drive module is fixed to the rotation-side swing connection plate, and the output end flange is fixed to the side swing-flexion and extension connection plate; the housing of the flexion and extension drive module is fixed to the side swing-flexion and extension connection plate, and the output end flange is fixed to the thigh structure;

[0011] The three rotation axes of the three drive modules of the hip joint assembly intersect at one point; when the rotation drive module is installed on the pelvis of the humanoid robot, its rotation axis has an inclination angle with the cross-section of the body; the angle between the axis of the rotation drive module and the axis of the side swing drive module is an acute angle, and the axis of the side swing drive module and the axis of the flexion and extension drive module are orthogonal.

[0012] According to the leg structure assembly of the humanoid robot provided by the present invention, the thigh structure includes a femur that is hollow and has an opening on the rear side. The femur is arranged to imitate the human thigh, and the front side and left and right sides of the femur are respectively provided with hollow structures; the output end drive module of the hip joint assembly and the knee joint drive module are installed on both sides of the upper end of the femur, and the output end drive module of the hip joint assembly and the knee joint drive module are coaxially arranged.

[0013] According to the leg structure assembly of the humanoid robot provided by the present invention, the knee joint structure includes a knee joint shaft, a knee joint end cover and a knee joint bearing. The knee joint shaft is provided through the upper end of the calf structure through the knee joint bearing, and both ends of the knee joint shaft are respectively installed at the lower end of the thigh structure through the knee joint end cover.

[0014] The knee joint transmission assembly includes a knee joint crank and a knee joint connecting rod. The large end of the knee joint crank is fixed to the output end flange of the knee joint drive module, and the small end is hinged to the upper end of the knee joint connecting rod. The lower end of the knee joint connecting rod is hinged to the calf structure. The length of the line between the axis of the knee joint drive module and the axis of the knee joint axis is the same as the length of the line connecting the two ends of the knee joint connecting rod. The two lines and the knee joint crank and the calf structure form a parallel four-bar linkage structure.

[0015] According to the leg structure assembly of the humanoid robot provided by the present invention, the ankle joint drive module includes a first ankle joint module and a second ankle joint module, the first ankle joint module and the second ankle joint module are symmetrically arranged on both sides of the thigh structure; the first ankle joint module and the second ankle joint module are respectively connected to the foot structure through the ankle joint transmission components, and the two groups of ankle joint transmission components are respectively symmetrical on both sides of the thigh structure, the knee joint structure, the calf structure and the foot structure; when the first ankle joint module and the second ankle joint module are driven synchronously, they are used to drive the foot structure to achieve plantar flexion / dorsiflexion movement, and when the first ankle joint module and the second ankle joint module are driven asynchronously, they are used to drive the foot structure to achieve eversion / adduction movement;

[0016] And / or, the axis of the ankle joint driving module is on the line connecting the axis of the knee joint driving module and the axis of the knee joint structure.

[0017] According to the leg structure assembly of the humanoid robot provided by the present invention, the ankle joint transmission component includes an ankle joint crank, an ankle joint upper connecting rod, an intermediate crank and an ankle joint lower connecting rod; the large end of the ankle joint crank is fixed to the output end flange of the ankle joint drive module, and the small end is hinged to the upper end of the ankle joint upper connecting rod; the lower end of the ankle joint upper connecting rod is hinged to the rear end of the intermediate crank, and the intermediate crank can be rotatably sleeved on the knee joint axis in the knee joint structure, the length of the line connecting the axis of the ankle joint drive module and the axis of the knee joint axis is the same as the length of the line connecting the two ends of the ankle joint upper connecting rod, and the two connecting lines and the rear ends of the ankle joint crank and the intermediate crank form a parallel four-bar linkage structure;

[0018] The upper end of the lower link of the ankle joint is hinged to the front end of the intermediate crank through a ball hinge, and the lower end of the lower link of the ankle joint is hinged to the foot structure through a ball hinge. The length of the calf structure is the same as that of the lower link of the ankle joint, and the two together with the front end of the intermediate crank and the foot structure form a parallel four-bar linkage structure.

[0019] According to the leg structure assembly of the humanoid robot provided by the present invention, the two intermediate cranks in the two sets of ankle joint transmission assemblies are located on both sides of the calf structure on the knee joint axis, a knee joint oil-free bushing is provided between the intermediate crank and the knee joint axis, and a knee joint sleeve is provided between the knee joint oil-free bushing and the calf structure;

[0020] And / or, the distance from the front end of the intermediate crank to the part where the ankle joint lower link is connected to the center of the intermediate crank is equal to the distance from the rear end of the intermediate crank to the part where the ankle joint upper link is connected to the center of the intermediate crank.

[0021] According to the leg structure assembly of the humanoid robot provided by the present invention, the calf structure includes a calf bone, which is arranged in the style of a human calf and has the structure of a calf. The calf bone is provided with a hollow structure, and the hollow structure is provided with anti-scoliosis ribs.

[0022] According to the leg structure assembly of the humanoid robot provided by the present invention, the foot mechanism includes a rear foot, a rear foot seat, a front foot seat, a rear foot pad, a forefoot, a forefoot pad, a foot leaf spring and a foot elastic hinge;

[0023] The rear foot seat and the front foot seat are fixed to the upper mounting surface of the rear foot, and the upper mounting surface has an inclination angle with the sole plane of the foot. The cross-axis structure includes a flexion-extension axis and a tilt axis. The two ends of the tilt axis are rotatably inserted into the rear foot seat and the front foot seat. A connecting seat is provided above the tilt axis. The flexion-extension axis passes through the connecting seat and is connected to the calf structure at both ends. The ankle joint transmission assembly is connected to the front foot seat.

[0024] The rear sole pad has the same shape as the bottom surface of the rear sole and fits against the bottom surface of the rear sole; the forefoot pad has the same shape as the bottom surface of the forefoot and fits against the bottom surface of the forefoot; the rear sole and the forefoot are rotatably connected via the foot elastic hinge, one end of the foot leaf spring is fixed on the rear sole and the other end is pressed on the forefoot, and the sole formed by the rear sole and the forefoot imitates the sole of the human foot.

[0025] According to another aspect of the present invention, a humanoid robot is provided, comprising the leg structure assembly of the humanoid robot described in any one of the above items.

[0026] In general, compared with the prior art, the above technical solutions conceived by the present invention provide a humanoid robot leg structure assembly and a humanoid robot:

[0027] 1. Considering that, given a certain drive module capacity, the lower the leg's moment of inertia around the base of the leg, the higher the frequency at which the leg can swing, the knee and ankle drive modules are moved upward to the upper end of the thigh structure. This structure, driven by a transmission assembly, enables the leg structure to mimic humanoid motion. This design features no drive module at the end, mass concentrated at the upper end, and low moment of inertia. This effectively reduces the torque demand of the upper drive module, thereby increasing the motion frequency, achieving high-dynamic motion of the leg structure, and improving the dynamic performance of the humanoid robot.

[0028] 2. The specific configuration of the three drive modules in the hip joint assembly enables three degrees of freedom of motion in the hip joint through coupling. The hip joint assembly is compact and has centralized mass. The three degrees of freedom axes of the hip joint intersect at a single point, reducing the complexity of forward and inverse kinematic calculations. The hip joint has a wide range of motion, essentially the same as that of the human hip joint. The hip joint's tilt angle aligns the center of gravity along the axis of the thigh and calf, saving energy when standing.

[0029] 3. Using a parallelogram linkage as a transmission component to move the knee and ankle joint drive modules up to the thigh, the humanoid robot's leg structure has the advantages of light weight, centralized mass, low end weight, low moment of inertia, simple structure, and a small number of parts.

[0030] 4. The main structural parts of the hip joint rotation-lateral swing connecting plate, hip joint lateral swing-flexion and extension connecting plate, femur, shin bone, and hindfoot can be manufactured through one-piece processing, reducing the number of parts and the complexity of the structure. The shape and proportion of the femur and shin bone conform to the characteristics of the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a front axonometric view of the leg structure assembly of the humanoid robot according to an embodiment of the present invention;

[0032] Figure 2 is a reverse isometric view of the leg structure assembly of the humanoid robot according to an embodiment of the present invention;

[0033] Figure 3 is a schematic structural diagram of a hip joint assembly according to an embodiment of the present invention;

[0034] Figure 4 is a schematic structural diagram of a knee joint transmission assembly according to an embodiment of the present invention, wherein the thigh structure is a cross-sectional view;

[0035] Figure 5is a schematic structural diagram of an ankle joint transmission assembly according to an embodiment of the present invention, wherein the thigh structure is a cross-sectional view;

[0036] Figure 6 is a cross-sectional view of a knee joint axis structure according to an embodiment of the present invention;

[0037] Figure 7 is a schematic diagram of an ankle joint structure and a foot structure according to an embodiment of the present invention;

[0038] Figure 8 2 is a schematic diagram of a double-leg structure composed of a leg structure according to an embodiment of the present invention;

[0039] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0040] 10. Hip joint assembly; 11. Rotation drive module; 12. Rotation-side swing connection plate; 13. Side swing drive module; 14. Side swing-flexion and extension connection plate; 15. Flexion and extension drive module; 20. Thigh structure; 21. Thigh bone; 22. Knee joint drive module; 23. Knee joint crank; 24. Knee joint connecting rod; 30. Knee joint assembly; 31. Knee joint shaft; 32. Knee joint end cover; 33. Knee joint sleeve; 34. Knee joint oil-free bushing; 35. Knee joint bearing; 40. Calf structure; 41. Calf bone; 50. Ankle joint assembly; 51. First Ankle joint module; 52. Second ankle joint module; 53. Ankle joint crank; 54. Ankle joint upper connecting rod; 55. Upper connecting rod oil-free bushing; 56. Intermediate crank; 57. Ankle joint lower connecting rod; 58. Flexion and extension axis; 59. Flip axis; 571. Ankle joint connecting rod joint bearing 1; 572. Lower connecting rod body; 573. Ankle joint connecting rod joint bearing 2; 60. Foot structure; 61. Heel of foot; 62. Rear foot seat; 63. Forefoot seat; 64. Heel of foot pad; 65. Forefoot; 66. Forefoot pad; 67. Foot leaf spring; 68. Foot elastic hinge; 70. Pelvis. DETAILED DESCRIPTION

[0041] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0042] See also Figure 1 and Figure 2 , this embodiment 1 provides a leg structure assembly of a humanoid robot, the leg structure assembly including a hip joint assembly 10, a thigh structure 20, a knee joint assembly 30, a calf structure 40, an ankle joint assembly 50 and a foot structure 60;

[0043] The hip joint assembly 10 includes three drive modules for realizing three-degree-of-freedom rotational motion of the human-like hip joint, namely flexion / extension, internal rotation / external rotation, and adduction / abduction motion. The output end drive module of the hip joint assembly 10 is installed at the upper end of the thigh structure 20;

[0044] The knee joint assembly 30 includes a knee joint structure, a knee joint drive module 22, and a knee joint transmission assembly. The lower end of the thigh structure 20 is rotatably connected to the upper end of the shank structure 40 via the knee joint structure to provide the shank structure 40 with flexion / extension freedom of movement. The knee joint drive module 22 is mounted on the upper end of the thigh structure 20. The knee joint drive module 22 is connected to the shank structure 40 via the knee joint transmission assembly, and is used to drive the shank structure 40 to achieve flexion / extension movement via the knee joint transmission assembly.

[0045] The ankle joint assembly 50 includes an ankle joint structure, an ankle joint drive module and an ankle joint transmission component. The ankle joint structure includes a cross-axis structure. The lower end of the calf structure 40 is rotatably connected to the foot structure 60 through the cross-axis structure to provide the foot structure 60 with plantar flexion / dorsiflexion movement freedom and eversion / adduction movement freedom. The ankle joint drive module is installed at the upper end of the thigh structure 20 and is located below the knee joint drive module 22. The ankle joint drive module is connected to the foot structure 60 through the ankle joint transmission component, and is used to drive the foot structure 60 through the ankle joint transmission component to achieve plantar flexion / dorsiflexion movement and eversion / adduction movement.

[0046] In some specific embodiments, reference Figure 3 The hip joint assembly 10 includes a rotation drive module 11, a rotation-roll connection plate 12, a roll drive module 13, a roll-flexion connection plate 14, and a flexion drive module 15. The rotation drive module 11 has a housing fixed to the pelvis 70 of the humanoid robot, and its output flange is fixed to the rotation-roll connection plate 12. The roll drive module 13 has a housing fixed to the rotation-roll connection plate 12, and its output flange is fixed to the roll-flexion connection plate 14. The flexion drive module 15 has a housing fixed to the roll-flexion connection plate 14, and its output flange is fixed to the thigh structure 20. The flexion drive module 15 is the output drive module of the hip joint assembly 10.

[0047] Thus, the rotation drive module 11 is used to drive the leg structure to rotate about its axis. The rotation-roll connection plate 12 is used to connect the rotation drive module 11 and the roll drive module 13. The roll drive module 13 is used to drive the leg structure to roll about its axis. The roll-flexion-extension connection plate 14 is used to connect the roll drive module 13 and the flexion-extension drive module 15. The flexion-extension drive module 15 is used to drive the leg structure to flex and extend about its axis. The hip joint assembly 10 has three degrees of freedom, capable of achieving rotation, roll, and flexion-extension movements that mimic the human hip joint.

[0048] refer to Figure 1-Figure 3 When the rotation drive module 11 is installed on the body of the humanoid robot, that is, on the pelvis, its rotation axis has an inclined angle with the cross-section of the body, that is, the axis of the rotation drive module 11 is not set in the vertical direction; thereby, the pelvis 70 where it is installed can be made into an inverted triangle shape, similar to the human pelvis 70, which can improve the stability of the pelvis 70 and make the structure more compact.

[0049] The axes of the rotation drive module 11 and the roll drive module 13 form an acute angle. For example, the axes of the two drive modules connected to the rotation-roll connection plate 12 are offset by 45°. This allows the center of gravity of the robot's upper body to fall along the axis of the thigh and calf, preventing the center of gravity from being too far back. This makes the robot more stable and energy-saving when standing, while also making the hip joint structure more compact. The tilt angle of the hip joint drive module places the center of gravity along the axis of the thigh and calf, saving energy when standing and preventing the buttocks from appearing too prominent.

[0050] The axes of the lateral swing drive module 13 and the flexion-extension drive module 15 are orthogonal. The three drive modules in the hip joint assembly 10 do not independently drive hip rotation, lateral swing, and flexion-extension movements. Instead, they are coupled to each other. By simultaneously controlling the rotation drive module 11, the lateral swing drive module 13, and the flexion-extension drive module 15, the leg structure can be driven to perform internal rotation / external rotation or adduction / abduction, or even compound movements with multiple degrees of freedom. Controlling the flexion-extension drive module 15 can also achieve single flexion / extension movements of the leg structure.

[0051] Moreover, the three rotation axes of the three drive modules of the hip joint assembly 10 intersect at one point. Thus, the rotation drive module 11 can help the lateral swing drive module 13 to provide torque on the lateral swing movement of the hip joint. Similarly, the lateral swing drive module 13 can help the flexion and extension drive module 15 to provide torque on the flexion and extension movement of the hip joint, thereby reducing the complexity of forward and inverse kinematic calculations.

[0052] In some specific embodiments, reference Figure 1 and Figure 2The thigh structure 20 includes a thigh bone 21 that is hollow and has an open back. The thigh bone 21 is arranged to imitate a human thigh. The front side and left and right sides of the thigh bone 21 are respectively provided with hollow structures. The shape and size of the thigh bone 21 imitate the shape and size of the human thigh. The middle and back of the thigh bone 21 are hollow, and the upper end and the lower end may also be hollow, that is, the thigh bone 21 may only include left and right side faces and the front side face. The front side of the thigh bone 21 is also the front side face. Figure 1 The output drive module of the hip joint assembly 10 and the knee joint drive module 22 are installed on both sides of the upper end of the femur 21, and the output drive module of the hip joint assembly 10 and the knee joint drive module 22 are coaxially arranged.

[0053] Specifically, the outer shell of the flexion / extension drive module 15 is fixed to the side swing-flexion / extension connecting plate 14, and the output flange is fixed to the femur 21. The femur 21 is a hollow structure, and the flexion / extension drive modules for the hip and knee joints are mounted on its upper end. Specifically, the upper end of the femur 21 is connected to the output flange of the hip joint flexion / extension drive module 15. The outer shell of the knee joint drive module 22 is fixed to the upper end of the femur 21, and the rotation axes of these two drive modules coincide. The lower end of the knee joint structure is rotatably connected to the upper part of the shank structure 40 through the knee joint structure. The lower end of the shank structure 40 is connected to the foot structure 60 through the ankle joint structure.

[0054] In some specific embodiments, reference Figure 1 、 Figure 2 and Figure 6 The knee joint structure includes a knee joint shaft 31, a knee joint end cover 32 and a knee joint bearing 35. The knee joint shaft 31 is passed through the upper end of the calf structure 40 through the knee joint bearing 35, and the two ends of the knee joint shaft 31 are respectively installed on the lower end of the thigh structure 20 through the knee joint end cover 32.

[0055] The outer diameter of the knee joint end cap 32 is symmetrically mounted in the two side axial holes of the lower end of the femur 21. The two ends of the knee joint shaft 31 are mounted on the inner holes of the knee joint end caps 32 on both sides. The knee joint end caps 32 are used to connect the knee joint shaft 31 to the femur 21 and press the parts of the knee joint shaft 31 to prevent their axial movement. Two knee joint bearings 35 are symmetrically mounted in the axial hole of the upper end of the calf bone 41. The inner diameter of the knee joint bearing 35 is mounted on the knee joint shaft 31 to support the calf bone 41 to rotate around the knee joint shaft 31 with low friction and ensure that the calf bone 41 is located at the center of the femur 21. All parts in the knee joint structure are symmetrical about the middle plane of the femur 21. As a result, all parts that need to move on the knee joint shaft 31 can rotate freely with low friction and ensure that their relative axial positions remain unchanged.

[0056] refer to Figure 4 The knee joint transmission assembly includes a knee joint crank 23 and a knee joint connecting rod 24. The large end of the knee joint crank 23 is fixed to the output end flange of the knee joint drive module 22, and the small end is hinged to the upper end of the knee joint connecting rod 24. The lower end of the knee joint connecting rod 24 is hinged to the calf structure 40. The length of the line between the axis of the knee joint drive module 22 and the axis of the knee joint axis 31 is the same as the length of the line connecting the two ends of the knee joint connecting rod 24. The two lines and the knee joint crank 23 and the calf structure 40 form a parallel four-bar linkage structure.

[0057] Because the knee drive module 22 and the hip flexion-extension drive module 15 are coaxial, the line connecting the axis of the knee drive module 22 and the axis of the knee axis 31 is the line connecting the two ends of the femur 21. The length of the line connecting the two ends of the femur 21 is the same as the length of the line connecting the two ends of the knee joint connecting rod 24. These two lines, together with the knee crank 23 and the calf bone 41, form a parallelogram linkage. As a result, the torque, position, and velocity output by the knee drive module 22 are transmitted one-to-one to the flexion and extension movement of the knee joint, thereby reducing computational complexity.

[0058] Please refer to Figure 1 、 Figure 2 、 Figure 4 and Figure 5 The knee joint drive module 22 is used to drive the knee crank 23 to rotate about its axis, thereby driving the knee connecting rod 24 to rotate about its axis. The knee connecting rod 24 then propels the calf bone 41 to rotate about the knee joint axis 31, thereby achieving flexion and extension of the knee joint. The knee joint has flexion and extension freedom, which is transmitted by the knee flexion / extension drive module through the knee crank 23-connecting rod transmission mechanism. The knee crank 23-connecting rod transmission mechanism is located within the cavity of the thigh assembly and on the longitudinal center plane of the cavity.

[0059] In some specific embodiments, the ankle joint drive module includes a first ankle joint module 51 and a second ankle joint module 52, and the first ankle joint module 51 and the second ankle joint module 52 are symmetrically arranged on both sides of the thigh structure 20; the first ankle joint module 51 and the second ankle joint module 52 are respectively connected to the foot structure 60 through the ankle joint transmission assembly, and the two groups of ankle joint transmission assemblies are symmetrical on both sides of the thigh structure 20, the knee joint structure, the calf structure 40 and the foot structure 60; when the first ankle joint module 51 and the second ankle joint module 52 are driven synchronously, they are used to drive the foot structure 60 to achieve plantar flexion / dorsiflexion movement, and when the first ankle joint module 51 and the second ankle joint module 52 are driven asynchronously, they are used to drive the foot structure 60 to achieve eversion / adduction movement;

[0060] The housings of the first ankle joint drive module 51 and the second ankle joint drive module 52 are each fixed to the femur 21, just below the knee joint drive module 22. The two ankle joint drive modules are symmetrically mounted on the thigh structure 20, just below the hip and knee joint modules. The ankle joint drive modules are located close to the hip flexion and extension axis of freedom, centralizing their mass and effectively reducing the load on the hip and knee joint drive modules 22 caused by the moment of inertia during leg swing.

[0061] Between the ankle joint assembly 50 and the foot structure 60 are two ankle drive modules, two ankle transmission chains, and a cross-axis structure. The two ankle transmission chains are symmetrical about the femur 21. Each transmission chain is divided into upper and lower sections. The upper section transmits power from the ankle drive module to the knee joint via a parallel four-bar linkage, while the lower section transmits power from the knee joint to the ankle joint via a spatial four-bar linkage. The two transmission chains and the ankle joint form a parallel mechanism. The cross-axis structure provides a rotation axis for plantar flexion / dorsiflexion and eversion / adduction movements of the foot. The foot structure 60 is connected to the ankle joint and two connecting rods, directly contacting the ground and supporting the entire body.

[0062] The axis of the ankle joint driving module is on the line connecting the axis of the knee joint driving module 22 and the axis of the knee joint structure.

[0063] In addition, according to the formula:

[0064]

[0065] Where τ represents the output torque of the drive module on the swing leg during normal walking, τ g is the moment due to gravity, τ J is the torque caused by joint acceleration, m is the total mass to be driven, l is the distance from the center of mass of the driving part to the rotation axis, θ is the current swing angle (zero point is when it is naturally drooping), and J is the moment of inertia of the driving part. Therefore, the smaller l is, that is, the closer the mass distribution is to the rotation axis, the smaller the output torque required by the drive module.

[0066] Therefore, the knee joint drive module 22 is coaxial with the hip joint flexion and extension drive module 15, which can minimize the impact of the additional rotational inertia brought by the knee joint drive module 22 during hip flexion and extension movements. The ankle joint drive module 1 is coaxial with the ankle joint drive module 2, which can make the ankle joint transmission chain symmetrical about the leg to reduce the complexity of kinematic calculations. The centers of the ankle joint drive module 1 and the ankle joint drive module 2 are on the line connecting the center of the knee joint drive module 22 and the center of the knee joint axis 31, and are closely attached to the bottom of the knee joint drive module 2. Therefore, the impact of the additional rotational inertia brought by the ankle joint drive module 1 and the ankle joint drive module 2 during hip flexion and extension movements and knee flexion and extension movements can be minimized.

[0067] Specifically, refer to Figure 5 and Figure 6 The ankle joint transmission assembly includes an ankle crank 53, an upper ankle link 54, an intermediate crank 56, and a lower ankle link 57. The large end of the ankle crank 53 is fixed to the output flange of the ankle joint drive module, and the small end is hinged to the upper end of the upper ankle link 54. The lower end of the upper ankle link 54 is hinged to the rear end of the intermediate crank 56, which is rotatably sleeved on the knee joint shaft 31 in the knee joint structure. The length of the line connecting the axis of the ankle joint drive module and the axis of the knee joint shaft 31 is the same as the length of the line connecting the two ends of the upper ankle link 54. These two lines, together with the rear ends of the ankle crank 53 and the intermediate crank 56, form a parallel four-bar linkage structure. The upper ankle links 54 are symmetrically distributed on both sides of the knee link 24. The lower end of the thigh structure 20 is rotatably connected to the upper end of the calf structure 40 via the knee joint shaft 31.

[0068] The upper end of the ankle joint lower link 57 is hinged to the front end of the intermediate crank 56 through a ball hinge, and the lower end of the ankle joint lower link 57 is hinged to the foot structure 60 through a ball hinge. The length of the calf structure 40 is the same as that of the ankle joint lower link 57. The two and the front end of the intermediate crank 56 and the foot structure 60 form a parallel four-bar linkage structure.

[0069] The lower ankle link 57 includes an ankle link joint bearing 1 571, a lower link rod body 572, and an ankle link joint bearing 2 573. The distances between the pin axes at both ends of the intermediate crank 56 and the axis of the center hole are equal. The ball joint end of the ankle link joint bearing 1 571 is connected to the pin at the front end of the intermediate crank 56, the screw end of the ankle link joint bearing 1 571 is fixed to the screw hole of the lower link rod body 572, the ball joint end of the ankle link joint bearing 2 573 is connected to the pin at the upper end of the front foot seat 63, and the screw hole end of the ankle link joint bearing 2 573 is fixed to the screw of the lower link rod body 572.

[0070] Therefore, ankle joint drive module 1 and ankle joint drive module 2 are used to rotate the ankle joint crank 53 around its axis, so that the small end of the ankle joint crank 53 drives the ankle joint upper link 54 to rotate around its axis, and the ankle joint upper link 54 pushes the ankle joint middle crank 56 to rotate around the knee joint axis 31. The length of the line connecting the center of the ankle joint drive module and the center of the knee joint axis 31 is the same as the length of the line connecting the two ends of the ankle joint upper link 54. The above two and the rear ends of the ankle joint crank 53 and the ankle joint middle crank 56 form a parallel four-link linkage. The ankle joint upper link 54 is symmetrically distributed on both sides of the knee joint link 24. Therefore, the torque, position and speed output by the ankle joint drive module can be transmitted one-to-one to the two parallel motion chains of the ankle joint, thereby reducing the calculation complexity.

[0071] Specifically, refer to Figure 5 and Figure 6 The two intermediate cranks 56 in the two groups of ankle joint transmission assemblies are located on both sides of the calf structure 40 on the knee joint shaft 31, and a knee joint oil-free bushing 34 is provided between the intermediate crank 56 and the knee joint shaft 31, and a knee joint sleeve 33 is provided between the knee joint oil-free bushing 34 and the calf structure 40; the knee joint sleeve 33 and the knee joint oil-free bushing 34 are symmetrically mounted on the knee joint shaft 31, and the center hole of the intermediate crank 56 is mounted on the outer diameter of the knee joint oil-free bushing 34. The knee joint oil-free bushing 34 is used to reduce the friction generated when the intermediate crank 56 and the knee joint shaft 31 rotate relative to each other, and the knee joint sleeve 33 is used to ensure the relative position of the intermediate crank 56 and the knee joint bearing 35 and reduce the side friction.

[0072] The inner diameter of the oil-free bushing 55 of the upper connecting rod of the ankle joint is fixedly mounted on the pin at the rear end of the intermediate crank 56, and the outer diameter of the oil-free bushing 55 of the upper connecting rod is hinged to be rotatably mounted on the lower end of the upper connecting rod 54 of the ankle joint, which is used to reduce the friction generated when the pin at the rear end of the intermediate crank 56 and the upper connecting rod 54 of the ankle joint rotate relative to each other.

[0073] The distance from the front end of the intermediate crank 56 to the center of the ankle lower link 57 is equal to the distance from the rear end of the intermediate crank 56 to the center of the intermediate crank 56.

[0074] The pin at the front end of the ankle joint intermediate crank 56 is connected to the ankle joint connecting rod joint bearing 571, and the two can rotate freely within a certain range as a ball joint. The distances from the pin axes at both ends of the intermediate crank 56 to the axis of the center hole are equal, and the distances from both ends of the intermediate crank 56 to the center hole are equal, so that the torque applied at both ends to the center is equal, so that the torque of the ankle joint driving module can be equally transmitted to both ends of the ankle joint intermediate crank 56, which can simplify the calculation.

[0075] In some specific embodiments, reference Figure 1 、 Figure 2 and Figure 5 The calf structure 40 includes a calf bone 41, which is designed to mimic the human calf. Its shape and dimensions mimic those of a human calf, creating a calf-like structure. The calf bone 41 is provided with a hollow structure, which is equipped with anti-lateral bending ribs. Two lower ankle links 57 are mounted sagittally symmetrically about the calf bone 41. The length of the calf bone 41 (i.e., the length between the rotation centers of the two ends of the calf bone 41) is the same as the length of the lower ankle links 57. Together with the intermediate crank 56 and the foot mechanism, they form a spatial four-bar linkage.

[0076] Therefore, the overall size and proportions of the thigh and calf are based on a normal Asian person with a height of approximately 1.8 meters. According to the national standard "GB 10000-88 Chinese Adult Human Dimensions," the ratio of the thigh and calf lengths of a normal male with a height of 1.83 meters is 532 / 421 = 1.26. The length of the femur 21, i.e., the thigh structure 20, is 505 mm (from the axis of the hip flexion and extension drive module 15 to the axis of the knee joint axis 31), and the length of the calf bone 41, i.e., the leg structure 40, is 400 mm (from the axis of the knee joint axis 31 to the axis of the ankle joint flexion and extension axis 58). The ratio of the two is 1.26, which is consistent with the human body. In terms of morphology, the human leg is also used as a model, with the overall shape being larger at the top and smaller at the bottom, because the human leg muscles are mainly concentrated in the upper half of the thigh and calf. This is consistent with the design principle of placing the drive module on top, which is used to make the humanoid robot leg beautiful while reducing the mass and moment of inertia of the thigh.

[0077] Regarding the design of the tibia 41, it should be noted that when a person is in an upright state, the tibia and tibia 41 are mainly used for support, so they are straight. However, during the process of walking, human muscles not only provide movement, but more importantly, they withstand tension and provide torque. Therefore, when designing the bones of the leg, one should not only consider imitating the human skeleton, but should take the shape of the entire leg as a reference; the parallel four-bar linkage structure of the ankle joint imitates the skeletal muscles of the human knee and ankle joint. The largest muscle used to drive the ankle joint is called the gastrocnemius muscle. One end of it is connected to the upper side of the knee joint, and the other end is directly connected to the heel below the ankle joint, forming a quadrilateral structure. In this way, the gastrocnemius muscle can plantar flex the ankle joint and flex the knee joint, which is similar to the design of the present invention.

[0078] In some specific embodiments, reference Figure 7 The foot mechanism includes a rear foot 61, a rear foot seat 62, a front foot seat 63, a rear foot pad 64, a forefoot 65, a forefoot pad 66, a foot leaf spring 67 and a foot elastic hinge 68;

[0079] The rear foot seat 62 and the forefoot seat 63 are fixed to the upper mounting surface of the rear foot 61. The upper mounting surface is angled with the plantar plane to increase the ankle joint dorsiflexion angle. The cross-axis structure includes a flexion-extension axis 58 and a tilt axis 59. The two ends of the tilt axis 59 are rotatably inserted into the rear foot seat 62 and the forefoot seat 63. A connecting seat is provided above the tilt axis 59. The flexion-extension axis 58 passes through the connecting seat and is connected to the calf structure 40 at both ends. The ankle joint transmission assembly is connected to the forefoot seat 63.

[0080] The flexion and extension axis 58 in the ankle joint, i.e., the ankle joint axis, passes through the hole at the lower end of the calf bone 41 and the hole on the connecting seat. The ankle joint flexion and extension angle rotates around the ankle joint axis. The flexion and extension axis 58 and the tilt axis 59 form a cross-axis structure. The two sides of the tilt axis 59 at the lower end of the ankle joint cross axis are rotatably installed in the two holes of the foot rear seat 62 and the foot front seat 63. The ankle joint lateral swing angle rotates around the pin axis on both sides of the tilt axis 59 at the lower end of the ankle joint cross axis. The flexion and extension axis 58 of the ankle joint cross axis is perpendicular to the lower end tilt axis 59 but does not intersect. Thus, the ankle joint structure is used to connect the calf structure 40 and the foot mechanism, while supporting the lateral swing and flexion and extension movements of the ankle joint.

[0081] The rear sole pad 64 has the same shape as the bottom surface of the rear sole 61 and fits against the bottom surface of the rear sole 61; the forefoot pad 66 has the same shape as the bottom surface of the forefoot 65 and fits against the bottom surface of the forefoot 65; the rear sole 61 and the forefoot 65 are rotatably connected via the foot elastic hinge 68. One end of the foot leaf spring 67 is fixed to the rear sole 61 and the other end is pressed against the forefoot 65. The sole formed by the rear sole 61 and the forefoot 65 is designed to mimic the sole of a human foot. The shape of the sole formed by the rear sole 61 and the forefoot 65 is similar to the outer contour and size of the human sole. Thus, the front and rear sole connection forms a passive metatarsophalangeal joint of the foot mechanism. The foot leaf spring 67 is used to provide a restoring force after the metatarsophalangeal joint is bent, and can store and release the force acting on the foot and the ground when the robot walks.

[0082] Furthermore, the main structural parts of the hip joint rotation-lateral swing connecting plate 12, the hip joint lateral swing-flexion and extension connecting plate 14, the femur 21, the calf bone 41, and the rear foot 61, such as the rear foot 61, the rear foot seat 62, the front foot seat 63, the rear foot pad 64, the forefoot 65, the forefoot pad 66 and the upper mounting surface can be manufactured respectively through one-piece processing.

[0083] Furthermore, the second embodiment provides a humanoid robot, which includes the leg structure assembly of the humanoid robot described in any one of the above items.

[0084] This embodiment is based on the existing technology and takes into account that a humanoid robot needs to achieve high dynamic motion. A feasible technical solution is to reduce the rotational inertia of its legs as much as possible. Based on this, a leg structure assembly of a high dynamic motion humanoid robot and a humanoid robot using the same are proposed, including a hip joint assembly 10, a thigh structure 20, a knee joint assembly 30, a calf structure 40, an ankle joint assembly 50 and a foot structure 60, which has six degrees of freedom of motion, such as Figure 8This embodiment proposes a high-dynamic humanoid robot leg structure. Using a parallel four-bar linkage, the knee joint drive module 22 is coaxial with the hip joint motor, and the ankle joint drive module is moved up to the thigh. This humanoid robot leg structure offers advantages such as light weight, centralized mass, low end weight, low moment of inertia, simple structure, few parts, easy assembly and maintenance, and a shape and proportions that conform to the characteristics of the human body.

[0085] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A leg structure assembly of a humanoid robot, characterized in that: Including hip joint assembly, thigh structure, knee joint assembly, calf structure, ankle joint assembly and foot structure; The hip joint assembly includes three drive modules for realizing three-degree-of-freedom rotational motion of a human-like hip joint, and the output end drive module of the hip joint assembly is installed at the upper end of the thigh structure; The knee joint assembly includes a knee joint structure, a knee joint drive module, and a knee joint transmission assembly. The lower end of the thigh structure is rotatably connected to the upper end of the shank structure via the knee joint structure to provide the shank structure with a degree of freedom of flexion / extension movement. The knee joint drive module is mounted on the upper end of the thigh structure and is connected to the shank structure via the knee joint transmission assembly, so as to drive the shank structure to achieve flexion / extension movement via the knee joint transmission assembly. The ankle joint assembly includes an ankle joint structure, an ankle joint drive module, and an ankle joint transmission component. The ankle joint structure includes a cross-axis structure. The lower end of the calf structure is rotatably connected to the foot structure via the cross-axis structure to provide the foot structure with plantar flexion / dorsiflexion and eversion / adduction degrees of freedom. The ankle joint drive module is installed at the upper end of the thigh structure and below the knee joint drive module. The ankle joint drive module is connected to the foot structure via the ankle joint transmission component, and is used to drive the foot structure to achieve plantar flexion / dorsiflexion and eversion / adduction movements via the ankle joint transmission component. The hip joint assembly includes a rotation drive module, a rotation-side swing connection plate, a side swing drive module, a side swing-flexion and extension connection plate, and a flexion and extension drive module; wherein the housing of the rotation drive module is used to be fixed to the pelvis of the humanoid robot, and the output end flange is fixed to the rotation-side swing connection plate; the housing of the side swing drive module is fixed to the rotation-side swing connection plate, and the output end flange is fixed to the side swing-flexion and extension connection plate; the housing of the flexion and extension drive module is fixed to the side swing-flexion and extension connection plate, and the output end flange is fixed to the thigh structure; The three rotation axes of the three drive modules of the hip joint assembly intersect at one point; when the rotation drive module is installed on the pelvis of the humanoid robot, its rotation axis has an inclination angle with the cross-section of the body; the angle between the axis of the rotation drive module and the axis of the side swing drive module is an acute angle, and the axis of the side swing drive module and the axis of the flexion and extension drive module are orthogonal.

2. The leg structure assembly of a humanoid robot according to claim 1, characterized in that: The thigh structure includes a hollow thigh bone with an open rear side. The thigh bone is designed to imitate the human thigh, and the front and left and right sides of the thigh bone are respectively provided with hollow structures; the output end drive module of the hip joint assembly and the knee joint drive module are installed on both sides of the upper end of the thigh bone, and the output end drive module of the hip joint assembly and the knee joint drive module are coaxially arranged.

3. The leg structure assembly of a humanoid robot according to claim 1, wherein: The knee joint structure includes a knee joint shaft, a knee joint end cover and a knee joint bearing. The knee joint shaft is passed through the upper end of the calf structure through the knee joint bearing, and both ends of the knee joint shaft are respectively installed on the lower end of the thigh structure through the knee joint end cover. The knee joint transmission assembly includes a knee joint crank and a knee joint connecting rod. The large end of the knee joint crank is fixed to the output end flange of the knee joint drive module, and the small end is hinged to the upper end of the knee joint connecting rod. The lower end of the knee joint connecting rod is hinged to the calf structure. The length of the line between the axis of the knee joint drive module and the axis of the knee joint axis is the same as the length of the line connecting the two ends of the knee joint connecting rod. The two lines and the knee joint crank and the calf structure form a parallel four-bar linkage structure.

4. The leg structure assembly of a humanoid robot according to any one of claims 1 to 3, characterized in that: The ankle joint drive module includes a first ankle joint module and a second ankle joint module, the first ankle joint module and the second ankle joint module are symmetrically arranged on both sides of the thigh structure; the first ankle joint module and the second ankle joint module are respectively connected to the foot structure through the ankle joint transmission assembly, and the two groups of ankle joint transmission assemblies are symmetrical on both sides of the thigh structure, the knee joint structure, the calf structure and the foot structure; the first ankle joint module and the second ankle joint module are used to drive the foot structure to achieve plantar flexion / dorsiflexion movement when driven synchronously, and to drive the foot structure to achieve eversion / adduction movement when driven asynchronously; And / or, the axis of the ankle joint driving module is on the line connecting the axis of the knee joint driving module and the axis of the knee joint structure.

5. The leg structure assembly of a humanoid robot according to claim 4, characterized in that: The ankle joint transmission assembly includes an ankle joint crank, an ankle joint upper connecting rod, an intermediate crank and an ankle joint lower connecting rod; the large end of the ankle joint crank is fixed to the output end flange of the ankle joint drive module, and the small end is hinged to the upper end of the ankle joint upper connecting rod; the lower end of the ankle joint upper connecting rod is hinged to the rear end of the intermediate crank, and the intermediate crank can be rotatably sleeved on the knee joint axis in the knee joint structure, the length of the line connecting the axis of the ankle joint drive module and the axis of the knee joint axis is the same as the length of the line connecting the two ends of the ankle joint upper connecting rod, and the two connecting lines and the rear ends of the ankle joint crank and the intermediate crank form a parallel four-bar linkage structure; The upper end of the lower link of the ankle joint is hinged to the front end of the intermediate crank through a ball hinge, and the lower end of the lower link of the ankle joint is hinged to the foot structure through a ball hinge. The length of the calf structure is the same as that of the lower link of the ankle joint, and the two together with the front end of the intermediate crank and the foot structure form a parallel four-bar linkage structure.

6. The leg structure assembly of a humanoid robot according to claim 5, characterized in that: The two intermediate cranks in the two sets of ankle joint transmission assemblies are located on both sides of the knee joint shaft, a knee joint oil-free bushing is provided between the intermediate crank and the knee joint shaft, and a knee joint sleeve is provided between the knee joint oil-free bushing and the lower leg structure; And / or, the distance from the front end of the intermediate crank to the part where the ankle joint lower link is connected to the center of the intermediate crank is equal to the distance from the rear end of the intermediate crank to the part where the ankle joint upper link is connected to the center of the intermediate crank.

7. The leg structure assembly of a humanoid robot according to any one of claims 1 to 3, characterized in that: The calf structure includes a calf bone, which is arranged in the manner of a human calf and has the structure of a calf. A hollow structure is provided on the calf bone, and an anti-scoliosis rib is provided on the hollow structure.

8. The leg structure assembly of a humanoid robot according to any one of claims 1 to 3, characterized in that: The foot structure includes a rear foot, a rear foot seat, a front foot seat, a rear foot pad, a forefoot, a forefoot pad, a foot leaf spring, and a foot elastic hinge; The rear foot seat and the front foot seat are fixed to the upper mounting surface of the rear foot, and the upper mounting surface has an inclination angle with the sole plane of the foot. The cross-axis structure includes a flexion-extension axis and a tilt axis. The two ends of the tilt axis are rotatably inserted into the rear foot seat and the front foot seat. A connecting seat is provided above the tilt axis. The flexion-extension axis passes through the connecting seat and is connected to the calf structure at both ends. The ankle joint transmission assembly is connected to the front foot seat. The rear sole pad has the same shape as the bottom surface of the rear sole and fits against the bottom surface of the rear sole; the forefoot pad has the same shape as the bottom surface of the forefoot and fits against the bottom surface of the forefoot; the rear sole and the forefoot are rotatably connected via the foot elastic hinge, one end of the foot leaf spring is fixed on the rear sole and the other end is pressed on the forefoot, and the sole formed by the rear sole and the forefoot imitates the sole of the human foot.

9. A humanoid robot, characterized in that: A leg structure assembly of a humanoid robot comprising any one of claims 1 to 8.

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