Bionic humanoid robot knee joint mechanism, robot and method

Abstract

The present invention discloses a bionic humanoid robot knee joint mechanism, a robot and a method, which solves the problem in the prior art that it is difficult for humanoid robots to squat and difficult to stand up after squatting, and has the beneficial effect of facilitating the humanoid robot to smoothly move from squatting to standing up. The specific scheme is as follows: A bionic humanoid robot knee joint mechanism includes a first power source, the first power source is arranged at the end of the thigh away from the calf, the first power source is connected to the middle section of the rocker, the two ends of the rocker are respectively connected to one end of the first connecting rod and one end of the second connecting rod, the other end of the first connecting rod is connected to the third connecting rod shaft, the end of the thigh close to the calf supports the knee joint shaft, the third connecting rod is rotatably connected to the third connecting rod shaft and the calf, the fourth connecting rod is rotatably connected to the third connecting rod shaft and the knee joint shaft, the fifth connecting rod is rotatably connected to the second connecting rod, the fifth connecting rod is rotatably connected to the knee joint shaft, and the short side end of the fifth connecting rod is rotatably connected to the calf.

Description

Technical Field

[0001] The present invention relates to the field of robotics technology, and in particular to a bionic humanoid robot knee joint mechanism, a robot and a method. 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 not only simulate human appearance, but also human behavior. They can move from squatting to standing, especially from a deep squat to an upright position. This is because when a person squats, the contact point between the thigh bone and the shin bone is far back, and the tendon connecting the quadriceps femoris is farther away from the contact point, resulting in a larger lever arm, which facilitates standing up from a squat. However, existing robots have some difficulties in achieving this goal for the following reasons:

[0004] Existing humanoid robots typically place the knee joint drive motor directly at the knee joint. The robot's knee joint requires a large joint drive torque only during the initial stage of rising from a squat, while the required drive torque is smaller during other stages. This motor placement requires the motor to have a large peak torque, resulting in a larger mass at the knee joint and reducing the robot's dynamic characteristics.

[0005] Some humanoid robots move the knee joint drive motor up to the base of the thigh and drive the knee joint movement through a set of four-bar linkage mechanisms. This arrangement cannot give the robot a large knee joint motion range close to that of humans. At the same time, after the robot squats, the distance between the connecting rod and the knee joint axis, that is, the small lever arm, makes it difficult for the robot to stand up, or it may not be able to perform a deep squat at all.

[0006] In addition, the foot movement of the humanoid robot is driven by a motor installed at the ankle, which makes the ankle mass larger, which is not conducive to the smooth movement of the robot's legs. Or it is driven by two sets of linear drives installed at the legs. Because the movement of the two sets of linear drives is severely coupled, during the movement of the foot, the two sets of linear drives need to be controlled simultaneously to meet the movement requirements of the foot. This process requires complex motion solution, which makes control more difficult. Summary of the Invention

[0007] In view of the deficiencies in the prior art, the present invention aims to provide a bionic humanoid robot knee joint mechanism, which enables the humanoid robot to squat and move from a squatting state to an upright state.

[0008] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0009] A bionic humanoid robot knee joint mechanism includes a first power source, which is arranged at one end of the thigh away from the calf, the first power source is connected to the middle section of a rocker, the two ends of the rocker are respectively connected to one end of the first connecting rod and one end of the second connecting rod, the other end of the first connecting rod is connected to the third connecting rod axis, the end of the thigh close to the calf supports the knee joint axis, the third connecting rod is rotatably connected to the third connecting rod axis and the calf, the fourth connecting rod is rotatably connected to the third connecting rod axis and the knee joint axis, the fifth connecting rod is rotatably connected to the second connecting rod, the fifth connecting rod is rotatably connected to the knee joint axis, and the short side end of the fifth connecting rod is rotatably connected to the calf. When the first power source is actuated, the third connecting rod is pushed to rotate around the knee joint axis through the first connecting rod, the third connecting rod and the fourth connecting rod, and the calf is driven to move through the second connecting rod, thereby realizing the movement of the calf relative to the thigh.

[0010] As described above, in a bionic humanoid robot knee joint mechanism, the calf supports the calf rotation axis, the fifth connecting rod is L-shaped, the long side end of the fifth connecting rod is rotatably connected to the second connecting rod through the first connecting rod axis, the middle of the fifth connecting rod is rotatably connected to the knee joint axis at a right angle, and the other end of the fifth connecting rod is rotatably connected to the calf rotation axis.

[0011] As described above, in the knee joint mechanism of a bionic humanoid robot, an inclined section is provided on the side of the calf close to the thigh, the side of the inclined section close to the first connecting rod is rotatably connected to the third connecting rod, and the other side of the inclined section supports the calf rotating shaft.

[0012] As described above, in a bionic humanoid robot knee joint mechanism, the calf supports the second connecting rod shaft, and the third connecting rod is rotatably connected to the second connecting rod shaft. When the humanoid robot stands, the third connecting rod shaft is set higher than the second connecting rod shaft, and the central axis of the second connecting rod shaft is located in front of the central axis of the knee joint shaft. The central axis of the third connecting rod shaft is set higher than the central axis of the knee joint shaft, and the first connecting rod shaft is located behind the knee joint shaft.

[0013] In the knee joint mechanism of a bionic humanoid robot as described above, when the humanoid robot moves from an upright state to a bent knee state, the second connecting rod axis gradually moves to the rear side of the third connecting rod axis.

[0014] In the above-mentioned bionic humanoid robot knee joint mechanism, the first connecting rod is connected to the middle section of the third connecting rod shaft, and the third connecting rod and the fourth connecting rod are sequentially arranged on both sides of the first connecting rod.

[0015] The knee joint mechanism of a bionic humanoid robot as described above, wherein the thigh portion includes two side plates, a hollow portion is formed between the two side plates, the first connecting rod passes through the hollow portion of the two side plates, one end of the side plate adjacent to the calf portion is bent outward to form a bent end, the third connecting rod axis and the knee joint axis are placed inside the bent ends of the two side plates, and the bent ends are arc-shaped;

[0016] The second connecting rod is arranged beyond the side plate of the thigh.

[0017] In a second aspect, the present invention also provides a bionic humanoid robot, including the above-mentioned bionic humanoid robot knee joint mechanism, a foot is arranged at the bottom of the calf, a second power source is arranged on the side of the calf close to the thigh, and the second power source is connected to the foot to drive the foot to move.

[0018] As described above, the second power source of the bionic humanoid robot includes two motors, which are respectively connected to the corresponding planetary reduction mechanisms through transmission components. The planetary reduction mechanisms are installed on the side of the calf close to the foot. The planetary frame of one group of planetary reduction mechanisms extends a longitudinal axis forward and backward to be connected to the foot, driving the foot to pitch and swing relative to the calf. The planetary frame of the other group of planetary reduction mechanisms is provided with a first bevel gear, which is engaged with the second bevel gear fixed to the foot, driving the foot to roll and swing relative to the calf.

[0019] In a third aspect, the present invention further provides a method for operating a bionic humanoid robot, comprising the following contents:

[0020] The thigh, the rocker, the first link and the fourth link form a four-bar linkage, the fifth link, the third link, the fourth link and the calf form a four-bar linkage, and the rocker, the second link, the fifth link and the thigh form a four-bar linkage. When the humanoid robot is in an upright state, when the first power source is activated, the first link, the third link and the fourth link drive the third link axis to rotate around the knee joint axis, and at the same time, the second link drives the calf to move, thereby achieving bending of the calf relative to the thigh, so that the humanoid robot can squat.

[0021] After the humanoid robot squats, the first power source moves in the opposite direction to achieve straightening of the calf relative to the thigh, and the humanoid robot turns from the squatting state to the upright state;

[0022] The second power source operates to drive movement of the foot relative to the lower leg.

[0023] The beneficial effects of the present invention are as follows:

[0024] In the present invention, the first power source is used as the driving power source of the knee joint and is arranged at one end of the thigh away from the calf, avoiding the first power source being arranged at the knee joint, which is equivalent to the first power source being installed at the hip joint, thereby reducing the leg rotational inertia; the thigh, the rocker, the first connecting rod and the fourth connecting rod form a four-bar linkage, the fifth connecting rod part, the third connecting rod, the fourth connecting rod and the calf form a four-bar linkage, the rocker, the second connecting rod, the fifth connecting rod and the thigh form a four-bar linkage, thus forming multiple sets of coupled connecting rod mechanisms at the knee joint. The fifth link connects the knee joint axis and the calf, and the connection between the fifth link and the calf forms a calf rotation axis, which can enable the calf rotation axis to continuously move from back to front relative to the thigh when the humanoid robot gradually stands up from a deep squat posture. This is similar to the state of a person gradually standing up from a squatting posture. The contact point between the thigh bone and the calf bone continuously moves from back to front, and the torque at the knee joint gradually decreases, thereby achieving a high degree of imitation of the human body's squatting movement, which not only reduces the peak torque of the first power source, but also significantly improves the working condition of the first power source.

[0025] 2) In the present invention, the fifth connecting rod is configured to be L-shaped, with the long side end of the fifth connecting rod being rotatably connected to the second connecting rod, and the right angle being rotatably connected to the lower end of the thigh through the knee joint axis, and the short side end being rotatably connected to the calf through the calf rotation axis. In this way, during the movement of the second connecting rod, the calf rotation axis is driven by the fifth connecting rod to move around the knee joint axis, which is conducive to realizing the squatting movement of the humanoid robot.

[0026] 3) The calf structure of the present invention is reasonably arranged. The calf is provided with an inclined section, which is beneficial to the arrangement of the second connecting rod axis and the arrangement of the knee joint axis close to the calf rotation axis. The structural arrangement is reasonable and will not hinder the relative movement between the thigh and the calf.

[0027] 4) In the present invention, the humanoid robot is provided with feet, and the second power source is located at a position above the calf to avoid the heavy mass at the ankle of the humanoid robot. The second power source drives the pitching and rolling swing of the foot through the transmission components and the planetary gear reduction mechanism, realizing low-torque transmission, which not only reduces the rotational inertia of the calf relative to the knee joint, but also meets the larger driving torque requirement of the ankle joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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.

[0029] Figure 1 It is a front view of a knee joint mechanism of a bionic humanoid robot according to one or more embodiments of the present invention.

[0030] Figure 2This is a schematic diagram of the bending of the calf in a knee joint mechanism of a bionic humanoid robot according to one or more embodiments of the present invention.

[0031] Figure 3 It is an enlarged schematic diagram of the structure of the knee joint in a bionic humanoid robot knee joint mechanism according to one or more embodiments of the present invention.

[0032] Figure 4 This invention Figure 1 Schematic diagram of the AA section.

[0033] Figure 5 This invention Figure 1 Schematic diagram of the BB section.

[0034] Figure 6 This invention Figure 1 Schematic diagram at the CC section.

[0035] Figure 7 is an enlarged schematic diagram of the foot of a bionic humanoid robot according to one or more embodiments of the present invention.

[0036] Figure 8 This is a schematic diagram of a bionic humanoid robot knee joint mechanism in an upright state according to one or more embodiments of the present invention.

[0037] Figure 9 This is a schematic diagram of a knee joint mechanism of a bionic humanoid robot when the calf is bent 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. thigh, 1011. first side plate, 1012. second side plate, 102. first end cover, 103. rocker, 104. first motor, 105. first bearing, 106. first connecting rod, 107. second connecting rod, 109. second end cover, 110. first connecting rod shaft, 111. third connecting rod, 112. second connecting rod shaft, 113. fourth connecting rod, 114. calf, 115. fifth connecting rod, 116. side cover, 117. timing belt, 118. bevel gear seat, 119. ankle joint cover, 120. bearing seat, 121. foot, 122. tilting section, 123. arc block;

[0040] 201. First wear-resistant gasket, 202. Third connecting rod shaft, 203. Second wear-resistant gasket, 204. Second bearing;

[0041] 301. Knee joint shaft, 302. Third wear-resistant gasket, 303. Lower leg shaft, 304. Support plate, 305. First synchronous pulley, 306. Second motor, 307. Fifth bearing, 308. Internal gear ring, 309. Fourth bearing, 310. Third bearing, 311. Retaining ring, 312. Second synchronous pulley, 313. First gear shaft, 314. Planetary gear shaft, 315. Fifth bearing, 316. Planetary gear, 317. First bevel gear, 318. Planetary carrier, 319. Bushing, 320. Second bevel gear, 321. Second gear shaft, 322. Ear plate. DETAILED DESCRIPTION

[0042] 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.

[0043] 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;

[0044] As introduced in the background art, in the prior art, humanoid robots have difficulty squatting and standing up after squatting. In order to solve the above technical problems, the present invention proposes a bionic humanoid robot knee joint mechanism.

[0045] Example 1

[0046] In a typical embodiment of the present invention, reference is made to Figure 1As shown, a bionic humanoid robot knee joint mechanism includes a first power source, a first power source is set at one end of the thigh 101 away from the calf 114, the first power source is connected to the middle section of the rocker 103, the two ends of the rocker 103 are respectively connected to one end of the first connecting rod 106 and one end of the second connecting rod 107, the other end of the first connecting rod 106 is connected to the third connecting rod shaft 202, the end of the thigh 101 close to the calf 114 supports the knee joint shaft, the third connecting rod 111 is rotatably connected to the third connecting rod shaft 202 and the calf 114, the fourth connecting rod 113 is rotatably connected to the third connecting rod shaft 202 and the knee joint shaft 301, the fifth connecting rod 115 is connected to the second connecting rod 107, and the fifth connecting rod 115 is connected The knee joint axis and the calf 114, the thigh 101, the rocker 103, the first link 106 and the fourth link 113 constitute a four-bar linkage mechanism, part of the fifth link 115, the third link 111, the fourth link 113 and the calf 114 constitute a four-bar linkage mechanism, the rocker 103, the second link 107, the fifth link 115 and the thigh 101 constitute a four-bar linkage mechanism, the first power source is actuated, and the calf 114 is driven to move around the knee joint axis 301 through the second link 107 and the fifth link 115, and at the same time, the calf 114 is driven to rotate around the calf rotation axis 303 through the first link 106, the third link 111 and the fourth link 113, thereby realizing the movement of the calf 114 relative to the thigh 101.

[0047] In this embodiment, the thigh 101 includes two side plates, which are respectively a first side plate 1011 and a second side plate 1012 fixedly connected. The first side plate 1011 and the second side plate 1012 have the same structure, and a hollow is formed between the two side plates. The first connecting rod 106 passes through the hollow of the two side plates, and the first side plate 1011 and the second side plate 1012 are arc-shaped on the side away from the calf 114. The arc-shaped side is used to set the first power source, and the first power source is the first motor 104. The output end of the first motor 104 is connected to the middle section of the rocker 103, and the rocker 103 is also provided in the hollow between the first side plate 1011 and the second side plate 1012. One end of the first side plate 1011 and the second side plate 1012 close to the calf 114 is bent outward to form a bent end, and the third connecting rod axis 202 and the knee joint axis 301 are placed inside the bent ends of the two side plates, and the side of the bent end is arc-shaped; the second connecting rod 107 is set beyond the side plate of the thigh 101.

[0048] Specifically, refer to Figure 3 As shown, an arc-shaped block 123 is provided on the side of the calf 114 close to the thigh 101 to serve as the knee of the humanoid robot, and an inclined section 122 is provided on the side of the calf 114 close to the thigh 101. Two U-shaped grooves are symmetrically provided on one end of the inclined section 122 close to the first connecting rod, and the second connecting rod shaft 112 crosses the two U-shaped grooves to rotatably connect the calf with the two third connecting rods 111, and the two third connecting rods are respectively placed in the two U-shaped grooves.

[0049] refer to Figure 1 and Figure 4 As shown, the large diameter end of the second connecting rod shaft 112 is processed with special-shaped opposite sides, which can be long strips, and the corresponding special-shaped grooves are processed at the junction of the shank portion 114 and the large diameter end of the second connecting rod shaft 112 to fix the second connecting rod shaft 112 circumferentially, and the small diameter end face of the second connecting rod shaft 112 is processed with threads and axially fixed to the shank portion 114 by screws.

[0050] refer to Figure 1 As shown, the rocker 103 is mounted on the output end of the first motor 104. There are two protruding ends on both sides of the rotation axis of the rocker 103. The distances between the two protruding ends relative to the rotation axis of the rocker are different. A short shaft is processed on each protruding end. The upper end of the first connecting rod 106 is rotatably connected to the short shaft of the long end of the rocker 103 through the first bearing 105 and is axially fixed by the first end cover 102. Figure 2 As shown, the lower end of the first connecting rod 106 is rotatably connected to the third connecting rod shaft 202 through the first bearing 105, the other ends of the two third connecting rods 111 are rotatably connected to the third connecting rod shaft 202 through the second bearing 204, and are symmetrically arranged on both sides of the first connecting rod 106, and the other ends of the two fourth connecting rods 113 are rotatably connected to the third connecting rod shaft 202 through the second bearing 204, and are symmetrically arranged on both sides of the third connecting rod 111.

[0051] refer to Figure 4 As shown, both ends of the third connecting rod shaft 202 are provided with special-shaped grooves, and the second end cover 109 is processed with corresponding special-shaped protrusions. The second end cover 109 is fixed to both ends of the third connecting rod shaft 202 by screws to axially fix each connecting rod, and the first wear-resistant gasket 201 is installed at each mutual joint surface of the first connecting rod 106, the third connecting rod 111, the fourth connecting rod 113 and the second end cover 109. The upper end of the second connecting rod 107 is rotatably connected to the short shaft of the short end of the rocker 103 through the first bearing 105, and is axially fixed by the first end cover 102. The lower end of the second connecting rod 107 is connected to the long side end of the fifth connecting rod 115 through the first connecting rod shaft 110. The second connecting rod is rotatably connected to the first connecting rod shaft through the first bearing 105, and a second wear-resistant gasket 203 is installed at the joint surface between the second connecting rod 107 and the fifth connecting rod 115.

[0052] refer to Figure 5As shown, the lower end of the thigh 101 is rotatably connected to the fourth connecting rod 113 and the fifth connecting rod 115 through the knee joint shaft 301. The two ends of the knee joint shaft 301 are processed with special-shaped opposite sides, which can be long strips. The joint between the thigh 101 and the knee joint shaft 301 is processed with corresponding special-shaped grooves to fix the knee joint shaft 301 circumferentially. Threaded holes are processed on both end surfaces of the knee joint shaft 301 and are axially fixed to the thigh 101 by screws. A third wear-resistant gasket 302 is provided at the contact point between the inner side of the calf 114 and the fifth connecting rod 115.

[0053] refer to Figure 3 As shown, the fifth connecting rod 115 is L-shaped, the long side end of the fifth connecting rod is rotatably connected to the second connecting rod, and the fifth connecting rod is rotatably connected to the knee joint axis at a right angle. The short side end of the fifth connecting rod 115 is rotatably connected to the calf 114 through the calf rotating shaft 303, and the two ends of the calf rotating shaft 303 are processed with special-shaped opposite sides, and the calf 114 and the support plate 304 are matched with the calf rotating shaft 303 at corresponding special-shaped grooves to fix the calf rotating shaft 303 circumferentially, and the two end surfaces of the calf rotating shaft 303 are processed with threaded holes, which are axially fixed to the calf 114 and the support plate 304 by screws, and the support plate 304 and the calf 114 are rigidly connected with screws.

[0054] It should be noted that the thigh 101, the rocker 103, the first link 106, the fourth link 113, the third link 111, the fifth link 115, and the calf 114 form a composite four-bar linkage, which transmits the rotation and torque output by the first motor 104 to the calf 114, driving the calf 114 to swing back and forth relative to the thigh 101. The thigh 101, the rocker 103, the second link 107, and the fifth link 115 form a four-bar linkage, which changes the relative position of the calf 114 to the thigh 101 during the leg movement. The front and rear positions of the rotation axis improve the force transmission performance of the knee joint, so that when the humanoid robot gradually stands up from a deep squat posture, the calf rotation axis 303 moves continuously from back to front relative to the thigh 101. This is similar to the state of a person gradually standing up from a squatting posture. The contact point between the thigh bone and the calf bone continuously moves from back to front, and the torque at the knee joint gradually decreases, achieving a high degree of imitation of the human body's squatting movement. It not only reduces the peak torque of the first power source, but also significantly improves the working condition of the first power source and ensures a larger range of motion of the calf relative to the thigh.

[0055] Example 2

[0056] This embodiment provides a bionic humanoid robot, referring to Figure 6 and Figure 7As shown, it includes a bionic humanoid robot knee joint mechanism as described in Example 1, a foot 121 is set at the bottom of the calf 114, the foot 121 can be a flat plate, and the shape of the foot is similar to that of a human foot. A second power source is set on the side of the calf 114 close to the thigh; the second power source includes two second motors, one of which is connected to the first gear shaft 313 at the ankle through a first transmission component such as a synchronous belt, and the foot is driven to roll and swing by the first bevel gear 317 after planetary deceleration, and the other second motor is connected to the second gear shaft 321 at the ankle through a second transmission component such as a synchronous belt, and drives the foot to pitch relative to the calf after planetary deceleration.

[0057] Specifically, two second motors 306 are symmetrically installed inside the calf part 114 near the knee joint (the calf part is close to the calf rotation axis), and the first synchronous pulleys 305 are respectively installed on the output shafts of the two second motors 306. A U-shaped opening is provided at the lower end of the calf part 114, and ear plates 322 are provided on both sides of the U-shaped opening. The ear plates 322 are processed with coaxial bearing seat holes, and two inner gear rings 308 are respectively installed in the bearing seat holes from the inner sides of the ear plates on both sides of the U-shaped opening, and are fixedly connected to the calf part 114 by screws. Two third bearings 310 are respectively installed in the bearing seat holes of the ear plates on both sides of the U-shaped opening, and are tightly fitted with the end faces of the inner gear ring 308.

[0058] refer to Figure 5 and Figure 6 As shown, the inner gear ring 308, the planetary gear 316, the first gear shaft 313 and the first bevel gear 317 at one side ear plate 322 constitute a planetary reduction mechanism, the first bevel gear 317 is a support frame for the planetary gear, the gear tooth portion of the first bevel gear protrudes from the inner gear ring 308, the first gear shaft 313 is installed inside the first bevel gear 317 through two fourth bearings 309, and is axially fixed by a retaining ring 311, the bevel gear seat 118 and the bearing seat 120 are fixedly provided at the foot, the second bevel gear is fixedly installed on the bevel gear seat 118, and the first bevel gear is meshed with the second bevel gear.

[0059] At the other ear plate, the planet carrier 318, the planet gear 316, the second gear shaft 321, and the inner ring gear 308 form a planetary reduction mechanism. The outer side of the right section of the planet carrier 318 cooperates with the third bearing 310 and is axially fixed by the retaining ring 311. The planet gear 316 is installed on the right section of the planet carrier 318 through the planet gear shaft 314 and the fifth bearing 315. The second gear shaft 321 is installed inside the right section of the planet carrier 318 through two fourth bearings 309 and is axially fixed by the retaining ring 311. A bearing seat hole is machined inside the left section of the planet carrier 318. The right extended shaft section of the first bevel gear 317 is installed in the bearing seat hole of the left section of the planet carrier 318 through two fifth bearings 307. The two fifth bearings 307 are separated and positioned by the shaft sleeve 319.

[0060] In fact, the first bevel gear 317 and the planetary carrier 318 together form a cross axis. The horizontal axis is rotatably connected to the ear plate of the calf 114 through two third bearings 310, and the longitudinal axis is rotatably connected to the front bearing seat 120 and the rear bevel gear seat 118 of the foot 121 through two fifth bearings 307. The second synchronous pulley 312 is respectively installed on the extended shaft sections of the first gear shaft 313 and the second gear shaft 321, and is closed and protected with an ankle joint cover 119. The first gear shaft is driven to rotate by the second synchronous pulley, and then the first bevel gear is driven to rotate, and the second bevel gear drives the foot 121 to roll and swing.

[0061] It should be noted that the left section of the planetary carrier 318 has an extending shaft extending in the front and rear directions, and the extending shaft is the longitudinal axis. The front longitudinal axis is fixed to the foot 121 through the fifth bearing 307 and the bearing seat 120, and the rear longitudinal axis is rotatably connected to the second bevel gear 320 through the fifth bearing 307, and the second bevel gear 320 is rigidly fixed to the foot 121 through the bevel gear seat 118.

[0062] In addition, vertical grooves are provided on both sides of the calf 114, and a synchronous belt 117 is installed in each of the two grooves to connect the first synchronous pulley 305 with the second synchronous pulley 312. When the second motor 306 drives the second gear shaft 321 to rotate through the synchronous belt 117, the planetary carrier 318 drives the foot to pitch relative to the calf after planetary deceleration. When the second motor 306 drives the first gear shaft 313 to rotate through the synchronous belt 117, the first bevel gear drives the second bevel gear 320 to rotate after deceleration by the planetary mechanism. Because of the setting of the cross axis, the second bevel gear 320 drives the foot 121 to rotate around the longitudinal axis, so that the foot 121 rolls relative to the calf 114. By reasonably controlling the movement of the two second motors 306, the pitch and roll swings of the foot 121 can be flexibly controlled to ensure full contact with the ground and maintain the stability of the humanoid robot. Side covers 116 are respectively provided on both sides of the calf 114.

[0063] A working method of a bionic humanoid robot, comprising the following contents:

[0064] The thigh 101, the rocker 103, the first link 106 and the fourth link 113 form a four-bar linkage, the part of the fifth link 115, the third link 111, the fourth link 113 and the calf 114 form a four-bar linkage, and the rocker 103, the second link 107, the fifth link 115 and the thigh 101 form a four-bar linkage. When the humanoid robot is in an upright state, when the first power source is actuated, the first link 106, the third link 111 and the fourth link 113 push the third link shaft 202 to rotate around the knee joint axis 301, and at the same time, the second link 107 drives the calf 114 to move, thereby achieving bending of the calf 114 relative to the thigh 101.

[0065] refer to Figure 8 、 Figure 9 As shown, when the humanoid robot is standing, the thigh 101 and the calf 114 are in a vertical line, and the knee joint torque is almost zero. During the movement of the humanoid robot, the first motor 104 drives the rocker 103 to rotate, and drives the calf 114 to rotate relative to the thigh 101 through the first connecting rod 106 and the second connecting rod 107. When the humanoid robot bends its knees from a standing position, the force point between the thigh 101 and the calf 114 continuously moves backward, which is similar to the contact point between the thigh and the calf continuously moving away from the patella during a squat. This continuously increases the force arm of the first connecting rod 106 relative to the calf shaft 303, always maintaining good force transmission characteristics at the knee joint, and significantly reducing the peak torque of the first motor 104.

[0066] When a person squats deeply, the contact point is far back and the patella is far away from the contact point. As the person stands up gradually, the contact point continues to approach the patella, which is conducive to the person's standing. When the humanoid robot moves from a squatting state to a standing state, the calf rotation axis 303 continues to move from back to front relative to the thigh 101, which is similar to the state of a person gradually standing up from a squatting posture. The contact point between the femur and the calf bone continues to move from back to front, and the torque at the knee joint gradually decreases, achieving a high degree of imitation of the human body's squatting movement, which not only reduces the peak torque of the first power source, but also significantly improves the working condition of the first power source.

[0067] 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 shall be included within the scope of protection of the present invention.

Claims

1. A bionic humanoid robot knee joint mechanism, characterized in that: The first power source is provided at one end of the thigh away from the calf, the first power source is connected to the middle section of the rocker, the two ends of the rocker are respectively connected to one end of the first connecting rod and one end of the second connecting rod, the other end of the first connecting rod is connected to the third connecting rod axis, the end of the thigh close to the calf supports the knee joint axis, the third connecting rod is rotatably connected to the third connecting rod axis and the calf, the fourth connecting rod is rotatably connected to the third connecting rod axis and the knee joint axis, the fifth connecting rod is rotatably connected to the second connecting rod, the fifth connecting rod is rotatably connected to the knee joint axis, and the short side end of the fifth connecting rod is rotatably connected to the calf. When the first power source is actuated, the third connecting rod is pushed to rotate around the knee joint axis through the first connecting rod, the third connecting rod and the fourth connecting rod, and the calf is driven to move through the second connecting rod, thereby realizing the movement of the calf relative to the thigh; The calf supports the calf rotation axis, the fifth connecting rod is L-shaped, the long side end of the fifth connecting rod is rotatably connected to the second connecting rod through the first connecting rod axis, the middle of the fifth connecting rod is rotatably connected to the knee joint axis at a right angle, and the other end of the fifth connecting rod is rotatably connected to the calf rotation axis; The calf supports the second connecting rod shaft, and the third connecting rod is rotatably connected to the second connecting rod shaft. When the humanoid robot stands, the third connecting rod shaft is set higher than the second connecting rod shaft, and the central axis of the second connecting rod shaft is located in front of the central axis of the knee joint shaft. The central axis of the third connecting rod shaft is set higher than the central axis of the knee joint shaft, and the first connecting rod shaft is located on the rear side of the knee joint shaft.

2. The bionic humanoid robot knee joint mechanism according to claim 1, characterized in that: An inclined section is provided on the side of the calf close to the thigh, and the side of the inclined section close to the first connecting rod is rotatably connected to the third connecting rod, and the other side of the inclined section supports the calf rotating shaft.

3. The bionic humanoid robot knee joint mechanism according to claim 1, characterized in that: When the humanoid robot moves from an upright state to a kneeling state, the second link shaft gradually moves to the rear side of the third link shaft.

4. The bionic humanoid robot knee joint mechanism according to claim 1, characterized in that: The first connecting rod is connected to the middle section of the third connecting rod shaft. The third connecting rod and the fourth connecting rod are sequentially arranged on both sides of the first connecting rod.

5. The bionic humanoid robot knee joint mechanism according to claim 1, characterized in that: The thigh portion includes two side plates, a hollow portion is formed between the two side plates, the first connecting rod passes through the hollow portion of the two side plates, one end of the side plate close to the calf portion is bent outward to form a bent end, the third connecting rod axis and the knee joint axis are placed inside the bent ends of the two side plates, and the bent ends are arc-shaped; The second connecting rod is arranged beyond the side plate of the thigh.

6. A bionic humanoid robot, characterized in that: A bionic humanoid robot knee joint mechanism comprising any one of claims 1-5, wherein a foot is arranged at the bottom of the calf, a second power source is arranged on the side of the calf close to the thigh, and the second power source is connected to the foot to drive the foot to move.

7. The bionic humanoid robot according to claim 6, characterized in that: The second power source includes two motors, which are respectively connected to corresponding planetary reduction mechanisms through transmission components. The planetary reduction mechanisms are installed on the side of the calf close to the foot. One set of planetary reduction mechanisms has a planetary frame extending forward and backward with a longitudinal axis connected to the foot, driving the foot to pitch and swing relative to the calf. The other set of planetary reduction mechanisms has a first bevel gear provided on the planetary frame, which is engaged with a second bevel gear fixed to the foot, driving the foot to roll and swing relative to the calf.

8. A method for operating a bionic humanoid robot according to claim 6 or 7, characterized in that: Includes the following: The thigh, the rocker, the first link and the fourth link form a four-bar linkage, the fifth link, the third link, the fourth link and the calf form a four-bar linkage, and the rocker, the second link, the fifth link and the thigh form a four-bar linkage. When the humanoid robot is in an upright state, when the first power source is activated, the first link, the third link and the fourth link drive the third link axis to rotate around the knee joint axis, and at the same time, the second link drives the calf to move, thereby achieving bending of the calf relative to the thigh, so that the humanoid robot can squat. After the humanoid robot squats, the first power source moves in the opposite direction to achieve straightening of the calf relative to the thigh, and the humanoid robot turns from the squatting state to the upright state; The second power source operates to drive movement of the foot relative to the lower leg.

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