A humanoid robot lower limb mechanism and working method thereof

Abstract

The present invention discloses a humanoid robot lower limb mechanism and a working method thereof, which solves the problem in the prior art that the position of the robot knee joint motor is too high, resulting in a small connecting rod force arm, and has the beneficial effect of increasing the motion range of the knee joint. The specific scheme is as follows: A humanoid robot lower limb mechanism includes a thigh and a calf, a first power source is connected to a first rocker arm, the first rocker arm is connected to one end of the knee joint connecting rod, the other end of the knee joint connecting rod is connected to the first connecting rod shaft, the end of the calf close to the thigh supports the second connecting rod shaft, the thigh supports the thigh gear shaft, the calf supports the calf gear shaft, the gear section of the thigh gear shaft and the gear section of the calf gear shaft are engaged with each other, one end of the first connecting rod is rotatably connected to the first connecting rod shaft, the other end of the first connecting rod is rotatably connected to the thigh gear shaft, one end of the second connecting rod is rotatably connected to the first connecting rod shaft, and the other end of the second connecting rod is rotatably connected to the second connecting rod shaft.

Description

Technical Field

[0001] The present invention relates to the field of robotics technology, in particular to a humanoid robot lower limb mechanism and a working method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Humanoid robots have excellent terrain adaptability and flexible working capabilities. They could replace manual labor in many industries in the future and hold broad application prospects. Consequently, the development of humanoid robots has attracted increasing attention from research institutions and businesses in recent years. During squats, the knee joint has a wide range of motion, approaching 180°, while the contact point between the thighbone and shin bone constantly shifts. When a person is in a deep squat, the angle between the thigh and shin bone is very small, requiring a significant amount of torque from the knee joint to stand up. At this point, the contact point between the thighbone and shin bone is positioned far back, and the tendon connecting the quadriceps femoris is farther from the contact point, resulting in a larger moment arm, which facilitates standing.

[0004] One of the existing humanoid robot knee joint drive solutions is to install a drive motor directly at the knee joint. This drive method can give the knee joint a larger range of motion, but the leg has a larger moment of inertia relative to the hip joint, which reduces the robot's motion performance. Another commonly used knee joint drive solution is to install a knee joint motor (CN202410243993.9, application date March 4, 2024) at the hip joint and drive the knee joint rotation through a four-bar linkage, or use a linear actuator (CN202311080903.0, application date August 25, 2023) installed inside the thigh to drive the knee joint rotation. The linear actuator, thigh rod, and shank rod form a four-bar linkage. Although this can achieve knee flexion or straightening, it cannot achieve a wide range of knee joint motion to prevent the four-bar linkage from approaching a singularity point to ensure good force transmission performance. Moreover, when the robot squats deeply, the connecting rod moves linearly and is close to the knee joint axis, resulting in a small connecting rod moment arm. However, the robot requires a very large knee joint torque to move from squatting to standing. The small connecting rod moment arm significantly increases the peak torque of the knee joint motor, causing the knee joint motor to operate under very harsh conditions. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a humanoid robot lower limb mechanism that not only ensures the movement performance of the legs but also significantly improves the working condition of the knee joint motor.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A humanoid robot lower limb mechanism includes a thigh and a calf. A first power source is provided at an end of the thigh away from the calf. The first power source is connected to a first rocker arm. The first rocker arm is connected to one end of a knee joint connecting rod. The other end of the knee joint connecting rod is connected to the first connecting rod shaft. The end of the calf close to the thigh supports the second connecting rod shaft. The thigh supports the thigh gear shaft. The calf supports the calf gear shaft. The gear section of the thigh gear shaft and the gear section of the calf gear shaft are engaged with each other. One end of the first connecting rod is rotatably connected to the first connecting rod shaft, the other end of the first connecting rod is rotatably connected to the thigh gear shaft, one end of the second connecting rod is rotatably connected to the first connecting rod shaft, and the other end of the second connecting rod is rotatably connected to the second connecting rod shaft. When the first power source works, the calf is pushed to swing relative to the thigh through the first rocker arm, the knee joint connecting rod, the first connecting rod and the second connecting rod.

[0008] In the humanoid robot lower limb mechanism as described above, the central axis of the thigh gear shaft is arranged higher than the central axis of the shank gear shaft;

[0009] When the bionic humanoid robot stands, the central axis of the first connecting rod shaft is higher than the central axis of the second connecting rod shaft, the central axis of the second connecting rod shaft is located in front of the central axis of the first connecting rod shaft, and the central axis of the second connecting rod shaft is higher than the central axis of the calf gear shaft.

[0010] In the humanoid robot lower limb mechanism as described above, the shaft segments on both sides of the gear segment in the thigh gear shaft and the calf gear shaft are connected by a third connecting rod, and the thigh gear shaft and the calf gear shaft are both rotationally connected to the third connecting rod.

[0011] The lower limb mechanism of a humanoid robot as described above, wherein a support fork is provided at one end of the calf portion close to the thigh portion, the support fork having an inclined section, the second connecting rod shaft being provided at the top of the inclined section, and the calf gear shaft being provided at the bottom of the inclined section, the support fork supporting the second connecting rod shaft and the calf gear shaft, and the third connecting rod being located on the inner side of the support fork;

[0012] Wear-resistant gaskets are provided between the inner side of the support fork and the third connecting rod, and between the third connecting rod and the gear section of the calf gear shaft.

[0013] In the lower limb mechanism of a humanoid robot as described above, the knee joint connecting rod is connected to the middle section of the first connecting rod shaft, and the second connecting rod and the first connecting rod are sequentially arranged on the two side shaft sections from the inside to the outside, and the shaft sections of the first connecting rod shaft rotatably support the second connecting rod and the first connecting rod.

[0014] As described above, a humanoid robot lower limb mechanism, the thigh portion includes a left thigh cover and a right thigh cover, the left thigh cover and the right thigh cover are buckled together, the left thigh cover and the right thigh cover are bent outward at one end close to the calf, and the inner holes of the bent ends of the left thigh cover and the right thigh cover cooperate with the special-shaped shaft sections at both ends of the thigh gear shaft to form circumferential fixation.

[0015] The humanoid robot lower limb mechanism as described above, wherein the first rocker arm is mounted on the output end of the first power source, a first short shaft is provided at an end of the first rocker arm away from its rotation axis, and the first short shaft is rotatably connected to the knee joint connecting rod;

[0016] The ends of the first connecting rod shaft and the second connecting rod shaft are both provided with shaft end retaining rings, and wear-resistant gaskets are provided between the knee joint connecting rod and the second connecting rod, between the second connecting rod and the first connecting rod, and between the first connecting rod and the corresponding shaft end retaining rings;

[0017] The second connecting rod is provided with wear-resistant pads on both sides of the second connecting rod shaft.

[0018] The lower limb mechanism of a humanoid robot as described above also includes the sole of the foot, which is connected to the calf. The calf is provided with a second power source, which is connected to the second rocker arm. The second rocker arm is rotatably connected to the sole of the foot through an ankle joint link. The calf, the second rocker arm, the ankle joint link and the sole of the foot form a four-bar linkage.

[0019] In a second aspect, the present invention further provides a method for operating a lower limb mechanism of a humanoid robot, comprising the following contents:

[0020] During the movement of the robot, the first power source drives the first rocker arm to rotate, and drives the calf to rotate relative to the thigh around the central axis of the thigh gear shaft through the knee joint link, the first link and the second link. In the process of the robot changing from a standing position to a knee-flexed state, the meshing point of the thigh gear shaft and the calf gear shaft, that is, the force point between the thigh and the calf, continuously moves toward the rear side of the robot, continuously increasing the force arm of the knee joint link relative to the meshing point of the thigh gear shaft and the calf gear shaft, always maintaining good force transmission characteristics of the knee joint, and significantly reducing the peak torque of the first power source.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1) The lower limb structure provided by the present invention places the first power source at the end of the thigh away from the calf, which is equivalent to the hip joint, thereby reducing the rotational inertia of the leg. The first rocker arm, the knee joint link, the first link and the thigh form a four-bar linkage, and the first link, the second link, the third link and the calf form another four-bar linkage, thus forming a composite linkage mechanism. The first power source, the first rocker arm, the knee joint link, the first link and the second link form a knee joint drive mechanism, which can effectively drive the movement of the calf relative to the thigh. Because a set of linkage mechanisms is located between the thigh and the calf, the calf can perform a 0°-180° bending movement relative to the thigh, significantly increasing the motion range of the knee joint and improving the motion performance of the humanoid robot.

[0023] 2) The present invention takes into account that when a person squats deeply, the contact point is far back and the patella is far away from the contact point. As the person gradually stands up, the contact point continues to approach the patella. When the person gradually stands up from a deep squat posture, the contact point between the thigh bone and the calf bone continues to move from back to front, and the torque at the knee joint gradually decreases. A pair of mutually meshing gears are supported by the thigh gear shaft and the calf gear shaft at the knee joint of the humanoid robot, so that when the humanoid robot gradually stands up from a deep squat posture, the force application point between the thigh and the calf continues to move from back to front, thereby achieving a high degree of imitation of the human body's squatting movement. During this process, the four-bar linkage composed of the first connecting rod, the second connecting rod, the calf and the third connecting rod ensure that the knee joint connecting rod always has a large lever arm, which not only reduces the peak torque of the first power source, but also significantly improves the working condition of the first power source.

[0024] 3) The first connecting rod shaft structure of the present invention is reasonably set up. The first connecting rod shaft is provided with a first connecting rod and a second connecting rod. The first connecting rod is rotatably connected to the thigh gear shaft, and the second connecting rod is connected to the second connecting rod shaft, thereby ensuring the setting of the connecting rod mechanism to promote the movement of the second connecting rod shaft when the knee joint connecting rod moves, thereby promoting the movement of the calf.

[0025] 4) The calf structure of the present invention is reasonably arranged. An inclined section is arranged at the top of the calf, a second connecting rod shaft is arranged at the top of the inclined section, and a calf gear shaft is arranged at the bottom of the inclined section, which is conducive to the arrangement of a four-bar linkage. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] Figure 1 It is a front view of a lower limb mechanism of a humanoid robot according to one or more embodiments of the present invention.

[0028] Figure 2is a schematic diagram of a lower limb mechanism of a humanoid robot according to one or more embodiments of the present invention.

[0029] Figure 3 This invention Figure 1 Schematic diagram of the AA section.

[0030] Figure 4 This invention Figure 1 Schematic diagram of the BB section.

[0031] Figure 5 This is another schematic diagram of the lower limb mechanism of a humanoid robot according to one or more embodiments of the present invention.

[0032] Figure 6 This invention Figure 5 A magnified diagram of the explosion at point E in the middle.

[0033] Figure 7 This invention Figure 2 Enlarged schematic diagram of point C in the middle.

[0034] Figure 8 This is a schematic diagram of a lower limb mechanism of a humanoid robot after removing the thigh portion according to one or more embodiments of the present invention.

[0035] Figure 9 This invention Figure 8 Enlarged schematic diagram of point D in the middle.

[0036] Figure 10 This is a simplified motion diagram of a humanoid robot in an upright state in a lower limb mechanism according to one or more embodiments of the present invention.

[0037] Figure 11 This is a simplified diagram of the robot knee flexion movement in the lower limb mechanism of a humanoid robot according to one or more embodiments of the present invention.

[0038] In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for reference only.

[0039] Wherein: 101. knee joint motor, 102. first rocker arm, 103. first bearing, 104. knee joint connecting rod, 105. thigh, 1051. left thigh cover, 1052. right thigh cover, 106. first connecting rod, 107. second connecting rod, 108. third connecting rod, 109. calf, 110. ankle joint motor, 111. second bearing, 112. second rocker arm, 113. ankle joint connecting rod, 114. sole, 115. support fork, 116. arc portion;

[0040] 201. Shaft end retaining ring, 202. First wear-resistant gasket, 203. Third bearing, 204. First connecting rod shaft, 205. Second wear-resistant gasket, 206. Second connecting rod shaft, 301. Thigh gear shaft, 302. Calf gear shaft, 303. Fixed plate, 304. Third wear-resistant gasket. DETAILED DESCRIPTION

[0041] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0042] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise clearly indicated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprising" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations;

[0043] As introduced in the background art, in the prior art, a humanoid robot has a problem in which the range of motion of the knee joint is limited after the power source of the knee joint is moved upward. In order to solve the above technical problem, the present invention proposes a lower limb mechanism of a humanoid robot.

[0044] Example 1

[0045] In a typical embodiment of the present invention, referring to Figure 1 and Figure 2 As shown, a humanoid robot lower limb mechanism includes a thigh 105 and a calf 109. A first power source is provided at one end of the thigh 105 away from the calf 109. The first power source is connected to a first rocker arm 102. The first rocker arm 102 is connected to one end of a knee joint link 104. The other end of the knee joint link 104 is connected to a first connecting rod shaft. An end of the calf 109 close to the thigh 105 supports a second connecting rod shaft 206. The thigh 105 supports a thigh gear shaft 301. The calf 109 supports a calf gear shaft 302. The gear segment of the thigh gear shaft 301 and the gear segment of the calf gear shaft 302 are meshed with each other. Figure 3As shown, one end of the first connecting rod 106 is rotatably connected to the first connecting rod shaft 204, the other end of the first connecting rod 106 is rotatably connected to the thigh gear shaft 301, one end of the second connecting rod 107 is rotatably connected to the first connecting rod shaft 204, and the other end of the second connecting rod 107 is rotatably connected to the second connecting rod shaft 206. The first power source is working, and the calf 109 is pushed to swing relative to the thigh 105 through the first rocker arm 102, the knee joint connecting rod 104, the first connecting rod 106 and the second connecting rod 107. The first power source is the knee joint motor 101, and the knee joint motor 101, the first rocker arm 102, the knee joint connecting rod 104, the first connecting rod 106, and the second connecting rod 107 constitute a knee joint driving mechanism.

[0046] Specifically, the thigh part 105 is composed of two parts rigidly connected, namely the left thigh cover 1051 and the right thigh cover 1052. The thigh part 105, the thigh gear shaft 301, the calf part 109, the calf gear shaft 302 and the third connecting rod 108 constitute a knee joint support mechanism, and the thigh gear shaft 301 serves as the knee joint axis.

[0047] refer to Figure 4 、 Figure 5 and Figure 6 As shown, the thigh 105 and the calf 109 are connected by the third connecting rod 108, a first gear is set in the middle of the thigh gear shaft 301, and a second gear is set in the middle of the calf gear shaft 302, the first gear and the second gear are meshed, and special-shaped shaft sections are processed at both ends of the thigh gear shaft 301, and the special-shaped shaft sections can be long strips. The shaft holes at the lower ends of the left thigh cover 1051 and the right thigh cover 1052 are processed with corresponding special-shaped grooves. The special-shaped shaft sections at both ends of the thigh gear shaft 301 cooperate with the special-shaped grooves of the shaft holes at the lower ends of the left thigh cover 1051 and the right thigh cover 1052 for circumferential fixation. Threaded holes are processed on both end surfaces of the thigh gear shaft 301, and the left thigh cover 1051 and the right thigh cover 1052 are fixed to the thigh gear shaft by screws;

[0048] The third connecting rod 108 and the first connecting rod 106 are sequentially arranged on both sides of the middle gear tooth section of the thigh gear shaft 301. The first connecting rod 106 and the third connecting rod 108 are rotatably connected to the thigh gear shaft 301; third bearings 203 are installed between the thigh gear shaft 301 and the third connecting rod 108 and the first connecting rod 106, and third wear-resistant gaskets 304 are arranged between the middle gear tooth section of the thigh gear shaft 301 and the third connecting rod 108, between the third connecting rod and the first connecting rod 106, and between the third connecting rod and the left thigh cover 1051 and the right thigh cover 1052.

[0049] It is easy to understand that both ends of the calf gear shaft 302 are processed with special-shaped shaft sections, and the calf part 109 and the fixing plate 303 are processed with special-shaped grooves that cooperate with the special-shaped shaft sections of the calf gear shaft 302. Circumferential fixation is achieved through the cooperation of the special-shaped grooves and the special-shaped shaft sections. Threaded holes are processed on both end surfaces of the calf gear shaft 302, and the calf gear shaft 302 is fixedly connected to the calf part 109 and the fixing plate 303 by screws. The shaft sections on both sides of the middle gear section of the calf gear shaft 302 support the third connecting rod 108 through the third bearing 203. A third wear-resistant gasket 304 is provided between the middle gear section of the calf gear shaft 302 and the third connecting rod 108, between the third connecting rod and the calf part 109, and between the third connecting rod and the fixing plate 303. The third wear-resistant gasket 304 located on the side of the third connecting rod is a whole piece, covering the thigh gear shaft 301 and the calf gear shaft 302.

[0050] Furthermore, the knee joint motor 101 is mounted on the upper end of the thigh 105, and the first rocker arm 102 is mounted on the output end of the knee joint motor 101. The first rocker arm 102 extends away from the rotation axis and is provided with a first short shaft. The first short shaft is connected to one end of the knee joint connecting rod 104, and the first short shaft is parallel to the central axis of the knee joint motor 101.

[0051] A first connecting rod shaft 204 is provided at one end of the thigh portion 105 close to the calf portion 109. The other end of the knee joint connecting rod 104 is rotatably connected to the first connecting rod shaft 204 via a first bearing 103. The two second connecting rods 107 are rotatably connected to the first connecting rod shaft 204 via a third bearing 203 and are symmetrically arranged on both sides of the knee joint connecting rod 104. The two first connecting rods 106 are rotatably connected to the first connecting rod shaft 204 via a third bearing 203 and are symmetrically arranged on the outside of the two second connecting rods 107. A second wear-resistant gasket 205 is provided between each connecting rod.

[0052] Threaded holes are respectively processed on both end faces of the first connecting rod shaft 204, and each connecting rod is axially fixed by screws and shaft end retaining rings 201. A first wear-resistant gasket 202 is arranged between the shaft end retaining ring 201 and the first connecting rod 106. The other ends of the two first connecting rods 106 are rotatably connected to the thigh gear shaft 301 through the third bearing 203, and the other ends of the two second connecting rods 107 are rotatably connected to the second connecting rod shaft 206 through the third bearing 203. The second connecting rod shaft 206 is installed in the shaft hole at the upper end of the calf part 109. Threaded holes are processed on both end faces of the second connecting rod shaft 206, and are fixed to the calf part 109 by two shaft end retaining rings 201 and screws.

[0053] It should be noted that the reference Figure 7As shown, after the left thigh cover 1051 and the right thigh cover 1052 are connected, the interior is hollow to set the knee joint connecting rod 104, and the left thigh cover and the right thigh cover in the thigh part 105 are bent outward at one end close to the calf, so that the distance between the left thigh cover 1051 and the right thigh cover 1052 is increased to set the first connecting rod, the second connecting rod and other components, and the width of the side of the thigh part 105 close to the calf part 109 gradually narrows.

[0054] refer to Figure 8 and Figure 9 As shown, an arc-shaped portion 116 is provided on one side of the calf portion 109 close to the thigh portion 105 to simulate the human patella, and a support fork 115 is provided at one end of the calf portion 109 close to the thigh portion 105. The support fork 115 has an inclined section, and a second connecting rod shaft is provided at the top of the inclined section. The second connecting rod shaft is provided close to the arc-shaped portion 116, and a calf gear shaft is provided at the bottom of the inclined section. The third connecting rod is located on the inner side of the support fork.

[0055] In this embodiment, the central axis of the thigh gear shaft 301 is arranged higher than the central axis of the calf gear shaft 302; when the bionic humanoid robot is standing, the central axis of the first connecting rod shaft 204 is higher than the central axis of the second connecting rod shaft 206, and the central axis of the second connecting rod shaft 206 is located in front of the central axis of the first connecting rod shaft 204. The central axis of the second connecting rod shaft 206 is higher than the central axis of the calf gear shaft 302, thereby ensuring the motion range of the four-bar linkage composed of the first connecting rod 106, the second connecting rod 107 and the calf part 109;

[0056] refer to Figure 1 As shown, the lower end of the calf 109 is rotatably connected to the sole 114, and a second power source is installed near the knee joint of the calf 109. The second power source is an ankle motor 110, and a second rocker arm 112 is installed at the output end of the ankle motor 110. The second rocker arm 112 is provided with a second short axis parallel to the axis of the ankle motor 110 at one end away from the rotation axis. One end of the ankle link 113 is rotatably connected to the second short axis through a second bearing 111, and the other end of the ankle link 113 is rotatably connected to the sole 114 through the second bearing 111. The calf 109, the second rocker arm 112, the ankle link 113 and the sole form a positive four-bar linkage. When the ankle motor 110 rotates, the ankle link 113 drives the sole 114 to pitch and swing relative to the calf 109 to achieve good contact with the ground.

[0057] like Figure 10 、 Figure 11As shown, when the robot is standing, the thigh 105 and the calf 109 are in a vertical line, and the knee joint torque is almost zero. During the movement of the robot, the knee joint motor 101 drives the first rocker arm 102 to rotate, and drives the calf 109 to rotate relative to the thigh 105 through the knee joint connecting rod 104 and the second connecting rod 107. When the robot bends its knees from a standing position, the meshing point of the thigh gear shaft 301 and the calf gear shaft 302, that is, the force point between the thigh 105 and the calf 109, continuously moves to the right, similar to the continuous movement of the thigh and calf contact point away from the patella during a person's squatting process. The force arm of the knee joint connecting rod 104 relative to the meshing point of the thigh gear shaft 301 and the calf gear shaft 302 is continuously increased, thereby always maintaining good force transmission characteristics at the knee joint and significantly reducing the peak torque of the knee joint motor 101.

[0058] Example 2

[0059] This embodiment discloses a method for operating the lower limb mechanism of a humanoid robot. Figure 10 and Figure 11 As shown, including the following:

[0060] During the movement of the robot, the first power source drives the first rocker arm 102 to rotate, and drives the calf 109 to rotate relative to the thigh 105 around the central axis of the thigh gear shaft through the knee joint link 104, the first link 106, and the second link 107. In the process of the robot changing from a standing position to a knee-flexed state, the meshing point of the thigh gear shaft 301 and the calf gear shaft 302, that is, the force point between the thigh and the calf, continuously moves toward the rear side of the robot, continuously increasing the force arm of the knee joint link relative to the meshing point of the thigh gear shaft and the calf gear shaft, always maintaining good force transmission characteristics at the knee joint, and significantly reducing the peak torque of the first power source.

[0061] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A humanoid robot lower limb mechanism, characterized in that: The calf comprises a thigh and a calf, a first power source is provided at an end of the thigh away from the calf, the first power source is connected to a first rocker arm, the first rocker arm is connected to one end of a knee joint connecting rod, the other end of the knee joint connecting rod is connected to the first connecting rod shaft, an end of the calf close to the thigh supports the second connecting rod shaft, the thigh supports the thigh gear shaft, the calf supports the calf gear shaft, the gear section of the thigh gear shaft and the gear section of the calf gear shaft are engaged with each other, one end of the first connecting rod is rotatably connected to the first connecting rod shaft, the other end of the first connecting rod is rotatably connected to the thigh gear shaft, one end of the second connecting rod is rotatably connected to the first connecting rod shaft, the other end of the second connecting rod is rotatably connected to the second connecting rod shaft, and when the first power source works, the calf is pushed to swing relative to the thigh through the first rocker arm, the knee joint connecting rod, the first connecting rod and the second connecting rod; The central axis of the thigh gear shaft is arranged higher than the central axis of the calf gear shaft; When the bionic humanoid robot is standing, the central axis of the first connecting rod shaft is higher than the central axis of the second connecting rod shaft, the central axis of the second connecting rod shaft is located in front of the central axis of the first connecting rod shaft, and the central axis of the second connecting rod shaft is higher than the central axis of the calf gear shaft; The shaft sections on both sides of the gear section in the thigh gear shaft and the calf gear shaft are connected via a third connecting rod, and both the thigh gear shaft and the calf gear shaft are rotationally connected to the third connecting rod.

2. A humanoid robot lower limb mechanism according to claim 1, characterized in that: A support fork is provided at one end of the calf portion close to the thigh portion, the support fork having an inclined section, the second connecting rod shaft is provided at the top of the inclined section, the calf gear shaft is provided at the bottom of the inclined section, and the third connecting rod is located on the inner side of the support fork; Wear-resistant gaskets are provided between the inner side of the support fork and the third connecting rod, and between the third connecting rod and the gear section of the calf gear shaft.

3. The humanoid robot lower limb mechanism according to claim 1, characterized in that: The knee joint connecting rod is connected to the middle section of the first connecting rod shaft. The second connecting rod and the first connecting rod are arranged in sequence on both side sections of the first connecting rod shaft from the inside to the outside. The sections of the first connecting rod shaft rotatably support the second connecting rod and the first connecting rod.

4. The humanoid robot lower limb mechanism according to claim 1, characterized in that: The thigh part includes a left thigh cover and a right thigh cover, which are buckled together. The ends of the left thigh cover and the right thigh cover close to the calf are bent outward, and the inner parts of the bent ends of the left thigh cover and the right thigh cover cooperate with the special-shaped shaft sections at both ends of the thigh gear shaft to form circumferential fixation.

5. The humanoid robot lower limb mechanism according to claim 1, characterized in that: The first rocker arm is installed at the output end of the first power source. A first short shaft is provided at one end of the first rocker arm away from its rotation axis. The first short shaft is rotatably connected to the knee joint connecting rod.

6. The humanoid robot lower limb mechanism according to claim 5, characterized in that: The ends of the first connecting rod shaft and the second connecting rod shaft are both provided with shaft end retaining rings, and wear-resistant gaskets are provided between the knee joint connecting rod and the second connecting rod, between the second connecting rod and the first connecting rod, and between the first connecting rod and the corresponding shaft end retaining rings; The second connecting rod is provided with wear-resistant pads on both sides of the second connecting rod shaft.

7. The humanoid robot lower limb mechanism according to claim 1, characterized in that: It also includes the sole of the foot, which is connected to the calf. The calf is provided with a second power source, the second power source is connected to the second rocker arm, and the second rocker arm is rotatably connected to the sole of the foot through an ankle joint connecting rod. The calf, the second rocker arm, the ankle joint connecting rod and the sole of the foot form a four-bar linkage.

8. A method for operating a lower limb mechanism of a humanoid robot according to any one of claims 1 to 7, characterized in that: Includes the following: During the movement of the robot, the first power source drives the first rocker arm to rotate, and drives the calf to rotate relative to the thigh around the central axis of the thigh gear shaft through the knee joint link, the first link and the second link. In the process of the robot changing from a standing position to a knee-flexed state, the meshing point of the thigh gear shaft and the calf gear shaft, that is, the force point between the thigh and the calf, continuously moves toward the rear side of the robot, continuously increasing the force arm of the knee joint link relative to the meshing point of the thigh gear shaft and the calf gear shaft, always maintaining good force transmission characteristics of the knee joint, and significantly reducing the peak torque of the first power source.

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