Leg structure assembly of humanoid robot and humanoid robot

Abstract

The invention belongs to the related technical field of robots, and discloses a leg structure assembly of a humanoid robot and the humanoid robot, and the leg structure assembly comprises a hip joint assembly and a leg structure assembly, the hip joint assembly comprises three driving modules, and three-degree-of-freedom rotation movement similar to human hips is achieved; the knee joint assembly comprises a knee joint structure, a knee joint driving module and a knee joint transmission assembly, the knee joint driving module is installed at the upper end of the thigh structure, and the knee joint transmission assembly drives the shank structure to bend and stretch; the ankle joint assembly comprises an ankle joint structure, an ankle joint driving module and an ankle joint transmission assembly, the ankle joint driving module is installed at the upper end of the thigh structure and located below the knee joint driving module, and the ankle joint transmission assembly drives the foot structure to achieve plantar flexion / dorsiflexion movement and extroversion / adduction movement. The driving modules are moved upwards to the upper ends of the thigh structures, and the humanoid robot has the advantages of being free of driving modules at the tail ends, concentrated in mass and small in rotational inertia, and the movement frequency of the humanoid robot can be improved.

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 always been a hot research direction, and creating autonomous machines that resemble humans has always been the ultimate goal of researchers. As technology continues to mature, people have begun to explore the huge potential of humanoid robots as general automation equipment to replace factory workers, and have invested a lot of resources in research and development. Because humanoid robots can seamlessly join the workflow and work with human workers, without the need to design specific sites and tools for them like other automation equipment, this gives humanoid robots greater application value.

[0003] At present, the driving modules of humanoid robots, such as motors and hydraulic devices, still cannot achieve the output torque-to-weight ratio of human muscles. The lightweight and strength of the structural parts of humanoid robots cannot be compared with human leg bones, which limits the movement frequency of the legs of humanoid robots and prevents the legs of robots from swinging at a higher frequency. On the other hand, the existing leg structures of humanoid robots still have problems such as complex structure, numerous parts, and complex assembly and maintenance.

[0004] Most existing robots, such as Japan's ASIMO robot, achieve humanoid motion by placing drive modules in situ at the joints of the leg structure to achieve rotation of the thigh, calf and foot. Existing robot leg structures usually have a high moment of inertia during humanoid motion, which limits the motion frequency. Summary of the invention

[0005] In view of 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 a high moment of inertia during humanoid movement and limits the movement frequency.

[0006] To achieve the above object, 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 component. The lower end of the thigh structure is rotatably connected to the upper end of the calf structure through the knee joint structure to provide the calf structure with a degree of freedom of flexion / extension movement. The knee joint drive module is installed at the upper end of the thigh structure. The knee joint drive module is connected to the calf structure through the knee joint transmission component to drive the calf structure to achieve flexion / extension movement through the knee joint transmission component.

[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 comprises 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 on the pelvis of the humanoid robot, and the output end flange is fixed on the rotation-side swing connection plate; the housing of the side swing drive module is fixed on the rotation-side swing connection plate, and the output end flange is fixed on the side swing-flexion and extension connection plate; the housing of the flexion and extension drive module is fixed on the side swing-flexion and extension connection plate, and the output end flange is fixed on the thigh structure;

[0011] The three rotation axes of the three driving modules of the hip joint assembly intersect at one point; when the rotation driving 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 driving module and the axis of the side swing driving module is an acute angle, and the axis of the side swing driving module and the axis of the flexion and extension driving 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 a 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 comprises 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 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 driving 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 driving module and the axis of the knee joint axis is the same as the length of the line between the two ends of the knee joint connecting rod. The two lines form a parallel four-bar structure with the knee joint crank and the calf 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; 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 they are synchronously driven, and the first ankle joint module and the second ankle joint module are used to drive the foot structure to achieve eversion / adduction movement when they are asynchronously driven;

[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 driving 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 driving 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 connecting rod 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 connecting rod 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 connecting rod 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 groups 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 part where the front end of the intermediate crank is connected to the lower connecting rod of the ankle joint to the center of the intermediate crank is equal to the distance from the part where the rear end of the intermediate crank is connected to the upper connecting rod of the ankle joint 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, the calf bone is arranged in imitation of the 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 an anti-lateral bending rib.

[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 on the upper mounting surface of the rear foot, the upper mounting surface has an inclination angle with the sole plane, the cross-axis structure includes a flexion-extension axis and a flip axis, the two ends of the flip axis are rotatably inserted in the rear foot seat and the front foot seat, a connecting seat is provided above the flip axis, the flexion-extension axis passes through the connecting seat and is connected to the calf structure at both ends, and 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 through 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, there is provided a humanoid robot comprising the leg structure assembly of the humanoid robot as 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 the lower the moment of inertia of the legs around the base of the legs is, the higher the frequency at which the legs can swing is, the knee joint drive module and the ankle joint drive module are moved to the upper end of the thigh structure. The leg structure can be driven by the transmission assembly to achieve humanoid motion. The leg structure has the characteristics of no drive module at the end, mass concentrated at the upper end, and small moment of inertia. It can effectively reduce the torque demand of the upper drive module, which is conducive to 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 setting of the three drive modules in the hip joint assembly can realize the movement of the three degrees of freedom of the hip joint through coupling. The hip joint assembly has a compact structure and concentrated mass. The three-degree-of-freedom axes of the hip joint intersect at one point, which can reduce the complexity of forward and inverse kinematics calculations. The hip joint has a large range of motion, which is basically the same as the range of motion of the human hip joint. The inclination angle of the hip joint makes the center of gravity on the axis of the thigh and calf, which saves more energy when standing;

[0029] 3. The parallel four-bar linkage structure is used as a transmission component to move the knee joint drive module and the ankle joint drive module up to the thigh, so that the leg structure of the humanoid robot has the advantages of light weight, concentrated weight, low end weight, small moment of inertia, simple structure and a small number of parts;

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

[0031] Figure 1 is a front axonometric view of a leg structure assembly of a 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 a 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 shaft system 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 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 one; 572. Lower connecting rod body; 573. Ankle joint connecting rod joint bearing two; 60. Foot structure; 61. Heel of foot; 62. Rear seat of foot; 63. Front seat of foot; 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 purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain 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 can 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 comprising 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 a 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 component. The lower end of the thigh structure 20 is rotatably connected to the upper end of the shank structure 40 through the knee joint structure to provide the shank structure 40 with a degree of freedom of flexion / extension movement. The knee joint drive module 22 is installed at the upper end of the thigh structure 20. The knee joint drive module 22 is connected to the shank structure 40 through the knee joint transmission component, and is used to drive the shank structure 40 to achieve flexion / extension movement through the knee joint transmission component.

[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 to achieve plantar flexion / dorsiflexion movement and eversion / adduction movement through the ankle joint transmission component.

[0046] In some specific embodiments, reference Figure 3 The hip joint assembly 10 includes a rotation drive module 11, a rotation-side swing connection plate 12, a side swing drive module 13, a side swing-flexion and extension connection plate 14 and a flexion and extension drive module 15; wherein the housing of the rotation drive module 11 is used to be fixed on the pelvis 70 of the humanoid robot, and the output end flange is fixed on the rotation-side swing connection plate 12; the housing of the side swing drive module 13 is fixed on the rotation-side swing connection plate 12, and the output end flange is fixed on the side swing-flexion and extension connection plate 14; the housing of the flexion and extension drive module 15 is fixed on the side swing-flexion and extension connection plate 14, and the output end flange is fixed on the thigh structure 20. The flexion and extension drive module 15 is the output end drive module of the hip joint assembly 10.

[0047] Thus, the rotation drive module 11 is used to drive the leg structure to rotate around its axis, the rotation-side swing connection plate 12 is used to connect the rotation drive module 11 and the side swing drive module 13, the side swing drive module 13 is used to drive the leg structure to side swing around its axis, the side swing-flexion and extension connection plate 14 is used to connect the side swing drive module 13 and the flexion and extension drive module 15, and the flexion and extension drive module 15 is used to drive the leg structure to flex and extend around its axis. The hip joint assembly 10 has three degrees of freedom and can realize the rotation, side swing and flexion and extension movements of 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, i.e., the pelvis, its rotation axis has an inclined angle with the cross section of the body, i.e., the axis of the rotation drive module 11 is not arranged in the vertical direction; thereby, the pelvis 70 where it is installed can be in 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 axis angle between the rotation drive module 11 and the side swing drive module 13 is an acute angle. For example, the axis offset angle of the two drive modules connected to the rotation-side swing connection plate 12 is 45°. Thus, the center of gravity of the upper body of the robot can be placed on the axis of the thigh and calf, avoiding the center of gravity being too far back, so that the robot is more stable and labor-saving when standing, and at the same time, the hip joint structure can be made more compact. The inclination angle of the hip joint drive module makes the center of gravity on the axis of the thigh and calf, saving more energy when standing, and the buttocks will not appear too prominent.

[0050] The axes of the lateral swing driving module 13 and the flexion and extension driving module 15 are orthogonal. Each of the three driving modules in the hip joint assembly 10 does not drive the rotation, lateral swing and flexion and extension of the hip joint independently, but is coupled to each other. By simultaneously controlling the rotation driving module 11, the lateral swing driving module 13 and the flexion and extension driving module 15, the leg structure can be made to perform internal rotation / external rotation or adduction / abduction, and a compound movement of multiple degrees of freedom can also be achieved; by controlling the flexion and extension driving module 15, the leg structure can be made to perform flexion / extension movement alone.

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

[0052] In some specific embodiments, reference Figure 1 and Figure 2The thigh structure 20 includes a thigh bone 21 which is hollow and has an opening at the rear. 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 a human thigh. The middle and rear 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 surfaces and a front side surface. The front side of the thigh bone 21, i.e., the front side surface, i.e., Figure 1 The output end 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 end drive module of the hip joint assembly 10 and the knee joint drive module 22 are coaxially arranged.

[0053] That is, the outer shell of the flexion and extension drive module 15 is fixed on the side swing-flexion and extension connecting plate 14, and the output end flange is fixed on the femur 21. The femur 21 adopts a hollow structure, and the upper end thereof is installed with the flexion / extension drive modules of the hip joint and the knee joint. Specifically, the upper end of the femur 21 is connected to the output flange of the hip joint flexion and extension drive module 15, and 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 the two drive modules coincide, and the lower end thereof is rotatably connected to the upper part of the calf structure 40 through the knee joint structure; the lower end of the calf 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 shaft holes of the lower end of the femur 21, and 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 with the femur 21 and press the parts on the knee joint shaft 31 to prevent their axial movement. Two knee joint bearings 35 are symmetrically mounted in the shaft hole at the upper end of the shin bone 41, and the inner diameter of the knee joint bearing 35 is mounted on the knee joint shaft 31, which is used to support the shin bone 41 to rotate around the knee joint shaft 31 with low friction, and ensure that the shin 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, so that all parts on the knee joint shaft 31 that need to move 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 driving 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 driving module 22 and the axis of the knee joint axis 31 is the same as the length of the line between 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 structure.

[0057] Since the knee joint drive module 22 and the hip joint flexion and extension drive module 15 are coaxial, the line between the axis of the knee joint drive module 22 and the axis of the knee joint axis 31 is the line between the two ends of the femur 21. The length of the line between the two ends of the femur 21 is the same as the length of the line between the two ends of the knee joint connecting rod 24. The above two, the knee joint crank 23, and the calf bone 41 form a parallel four-bar linkage, so that the torque, position and speed output by the knee joint drive module 22 can be transmitted to the flexion and extension movement of the knee joint in a one-to-one ratio, thereby reducing the calculation 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 joint crank 23 to rotate around its axis, so that the small end of the knee joint crank 23 drives the knee joint connecting rod 24 to rotate around its axis, and the knee joint connecting rod 24 drives the calf bone 41 to rotate around the knee joint axis 31, thereby realizing the flexion and extension movement of the knee joint. The knee joint has a flexion / extension degree of freedom, and the knee joint flexion / extension drive module transmits the movement through the knee joint crank 23-connecting rod transmission mechanism. The knee joint crank 23-connecting rod transmission mechanism is located in the cavity of the thigh assembly and is located 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 components, and the two groups of ankle joint transmission components are symmetrical on both sides of the thigh structure 20, the knee joint structure, the calf structure 40 and the foot structure 60; the first ankle joint module 51 and the second ankle joint module 52 are used to drive the foot structure 60 to achieve plantar flexion / dorsiflexion movement when they are synchronously driven, and the first ankle joint module 51 and the second ankle joint module 52 are used to drive the foot structure 60 to achieve eversion / adduction movement when they are asynchronously driven;

[0060] The shells of the ankle joint drive module 1, i.e., the first ankle joint module 51, and the ankle joint drive module 2, i.e., the second ankle joint module 52, are respectively fixed on the femur 21 and are close to the bottom of the knee joint drive module 22. The two ankle joint drive modules are symmetrically mounted on the thigh structure 20 and are close to the bottom of the hip and knee joint modules. The ankle joint drive module is close to the axis of the hip joint flexion and extension freedom, and the mass is concentrated, which effectively reduces the load of the rotational inertia on the hip and knee joint drive modules 22 when the leg swings.

[0061] There are two ankle joint drive modules, two ankle joint transmission chains and a cross-axis structure between the ankle joint assembly 50 and the foot structure 60. The two ankle joint transmission chains are symmetrical about the femur 21. Each transmission chain is divided into upper and lower sections. The upper section is transmitted from the ankle joint drive module to the knee joint through a parallel four-bar linkage mechanism, and the lower section is transmitted from the knee joint to the ankle joint through a spatial four-bar linkage mechanism. The two transmission chains and the ankle joint form a parallel mechanism; the cross-axis structure provides a rotation axis for plantar flexion / dorsiflexion, eversion / adduction movements of the foot. The foot structure 60 is connected to the ankle joint and two connecting rods, directly in contact with the ground and supports 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 swinging 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 (when the zero point is natural droop), and J is the moment of inertia of the driving part. Therefore, when l is smaller, 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 extra 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 transmission chain of the ankle joint 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 centers of the knee joint drive module 22 and the knee joint axis 31, and are closely attached to the bottom of the knee joint drive module 22. Therefore, the impact of the extra 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 joint crank 53, an ankle joint upper connecting rod 54, an intermediate crank 56 and an ankle joint lower connecting rod 57; the large end of the ankle joint crank 53 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 54; the lower end of the ankle joint upper connecting rod 54 is hinged to the rear end of the intermediate crank 56, and the intermediate crank 56 can be rotatably sleeved on the knee joint shaft 31 in the knee joint structure, and 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 ankle joint upper connecting rod 54, and the two connecting lines and the rear ends of the ankle joint crank 53 and the intermediate crank 56 form a parallel four-bar structure; the ankle joint upper connecting rod 54 is symmetrically distributed on both sides of the knee joint connecting rod 24. The lower end of the thigh structure 20 is rotatably connected to the upper end of the calf structure 40 through 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, and the two together with 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 from the axes of the pins at both ends of the intermediate crank 56 to the axes 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 connecting rod 54 to rotate around its axis, and the ankle joint upper connecting rod 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 connecting rod 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-bar linkage, and the ankle joint upper connecting rod 54 is symmetrically distributed on both sides of the knee joint connecting rod 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 sleeved on the knee joint shaft 31, and the center hole of the intermediate crank 56 is sleeved 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 upper connecting rod oil-free bushing 55 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 upper connecting rod oil-free bushing 55 is hinged to be rotatably mounted to the lower end of the upper connecting rod 54 of the ankle joint, so as 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 part where the front end of the intermediate crank 56 is connected to the lower ankle link 57 to the center of the intermediate crank 56 is equal to the distance from the part where the rear end of the intermediate crank 56 is connected to the upper ankle link 54 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 arranged in the manner of a human calf. The shape and size of the calf bone 41 are in the manner of a human calf, and the calf bone 41 has a calf structure. The calf bone 41 is provided with a hollow structure, and an anti-lateral bending rib is provided at the hollow structure. Two lower ankle joint connecting rods 57 are installed symmetrically about the sagittal plane of 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 joint connecting rod 57. The two together with the intermediate crank 56 and the foot mechanism form a spatial four-bar linkage.

[0076] Therefore, in terms of the overall size and proportion of the thigh and calf, a normal Asian with a height of about 1.8m is used as a reference. According to the national standard "GB 10000-88 Chinese Adult Human Dimensions", the length ratio of the thigh and calf of a normal male with a height of 1.83m is 532 / 421=1.26, and the length of the thigh bone 21, i.e., the thigh structure 20, is 505mm (from the axis of the hip joint 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 calf structure 40, is 400mm (from the axis of the knee joint axis 31 to the axis of the ankle joint flexion and extension axis 58), and 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, and the overall upper part is large and the lower part is small, because the human leg muscles are mainly concentrated in the upper part of the thigh and calf, which is consistent with the design principle of the upper placement of the drive module, and is used to make the legs of the humanoid robot 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 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 which 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, so that 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 front foot seat 63 are fixed on the upper mounting surface of the rear foot 61, and the upper mounting surface has an inclination angle with the sole plane, and the upper mounting surface has an inclination angle with the sole plane, which is used to increase the ankle joint dorsiflexion angle. The cross-axis structure includes a flexion-extension axis 58 and a flip axis 59, and the two ends of the flip axis 59 are rotatably inserted in the rear foot seat 62 and the front foot seat 63. A connecting seat is provided above the flip axis 59, and 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 front foot 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 flexion and extension angle of the ankle joint rotates around the axis of the ankle joint axis. The flexion and extension axis 58 and the turning axis 59 form a cross-axis structure. The two sides of the turning 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 lateral swing angle of the ankle joint rotates around the axis of the pins at both sides of the turning 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 turning axis 59 at the lower end but does not intersect. Thus, the ankle joint structure is used to connect the calf structure 40 and the foot mechanism, and simultaneously supports 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 on 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 on the bottom surface of the forefoot 65; the rear sole 61 and the forefoot 65 are rotatably connected through the foot elastic hinge 68, one end of the foot leaf spring 67 is fixed on the rear sole 61, and the other end is pressed on the forefoot 65, and the sole formed by the rear sole 61 and the forefoot 65 is set to imitate the sole of the human body. The shape of the sole formed by the rear sole 61 and the forefoot 65 is similar to the shape and size of the outer contour of the sole of the human body. Therefore, the front and rear sole connection parts form a passive metatarsophalangeal joint of the foot mechanism, and the foot leaf spring 67 is used to provide restoring force after the metatarsophalangeal joint is bent, and can store and release the force acting on the foot when the robot walks.

[0082] Furthermore, the main structural parts of the hip rotation-lateral swing connecting plate 12, the hip 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 prior art 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 have six degrees of freedom of motion, such as Figure 8As shown. This embodiment proposes a leg structure of a humanoid robot with high dynamic motion, using a parallel four-bar linkage to make the knee joint drive module 22 coaxial with the hip joint motor, and the ankle joint drive module moved up to the thigh. The leg structure of the humanoid robot has the advantages of light weight, concentrated weight, low end weight, small moment of inertia, simple structure, small number of parts, easy assembly and maintenance, and shape and proportions that conform to human characteristics.

[0085] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope 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 component. The lower end of the thigh structure is rotatably connected to the upper end of the calf structure through the knee joint structure to provide the calf structure with a degree of freedom of flexion / extension movement. The knee joint drive module is installed at the upper end of the thigh structure. The knee joint drive module is connected to the calf structure through the knee joint transmission component to drive the calf structure to achieve flexion / extension movement through the knee joint transmission component. 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.

2. The leg structure assembly of a humanoid robot as claimed in claim 1, characterized in that: The hip joint assembly comprises 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 on the pelvis of the humanoid robot, and the output end flange is fixed on the rotation-side swing connection plate; the housing of the side swing drive module is fixed on the rotation-side swing connection plate, and the output end flange is fixed on the side swing-flexion and extension connection plate; the housing of the flexion and extension drive module is fixed on the side swing-flexion and extension connection plate, and the output end flange is fixed on the thigh structure; The three rotation axes of the three driving modules of the hip joint assembly intersect at one point; when the rotation driving 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 driving module and the axis of the side swing driving module is an acute angle, and the axis of the side swing driving module and the axis of the flexion and extension driving module are orthogonal.

3. The leg structure assembly of a humanoid robot as claimed in claim 1, characterized in that: The thigh structure includes a thigh bone that is hollow and has an opening at the rear. The thigh bone is designed to imitate a human thigh, and the front side 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.

4. The leg structure assembly of a humanoid robot as claimed in claim 1, characterized in that: The knee joint structure comprises a knee joint shaft, a knee joint end cover and a knee joint bearing, wherein 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 at 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 driving 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 driving module and the axis of the knee joint axis is the same as the length of the line between the two ends of the knee joint connecting rod. The two lines form a parallel four-bar structure with the knee joint crank and the calf structure.

5. The leg structure assembly of a humanoid robot according to any one of claims 1 to 4, characterized in that: The ankle joint drive module comprises a first ankle joint module and a second ankle joint module, wherein 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 synchronously driven, 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 asynchronously driven, they are used to drive the foot structure to achieve eversion / adduction movement; 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.

6. The leg structure assembly of a humanoid robot as claimed in claim 5, characterized in that: The ankle joint transmission assembly comprises 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 driving 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 shaft in the knee joint structure, the length of the line connecting the axis of the ankle joint driving module and the axis of the knee joint shaft 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 connecting rod 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 connecting rod 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 connecting rod 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.

7. The leg structure assembly of a humanoid robot as claimed in claim 6, characterized in that: The two intermediate cranks in the two groups of ankle joint transmission assemblies are located on both sides of the calf structure on 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 calf structure; And / or, the distance from the part where the front end of the intermediate crank is connected to the lower connecting rod of the ankle joint to the center of the intermediate crank is equal to the distance from the part where the rear end of the intermediate crank is connected to the upper connecting rod of the ankle joint to the center of the intermediate crank.

8. The leg structure assembly of a humanoid robot according to any one of claims 1 to 4, characterized in that: The calf structure comprises a calf bone, which is arranged in the manner of a human calf and has the structure of a calf. A hollow structure is arranged on the calf bone, and an anti-lateral bending rib is arranged at the hollow structure.

9. The leg structure assembly of a humanoid robot according to any one of claims 1 to 4, characterized in that: 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; The rear foot seat and the front foot seat are fixed on the upper mounting surface of the rear foot, the upper mounting surface has an inclination angle with the sole plane, the cross-axis structure includes a flexion-extension axis and a flip axis, the two ends of the flip axis are rotatably inserted in the rear foot seat and the front foot seat, a connecting seat is provided above the flip axis, the flexion-extension axis passes through the connecting seat and is connected to the calf structure at both ends, and 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 through 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.

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

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