Lower limb assembly and humanoid robot

Abstract

The invention discloses a lower limb assembly and a humanoid robot. The lower limb assembly comprises a shank, a sole, a connecting piece, a first driving mechanism and a second driving mechanism. The connecting piece comprises a first shaft part and a second shaft part, the central axis of the first shaft part and the central axis of the second shaft part perpendicularly intersect, the bottom of the shank is pivoted to the first shaft part, and the sole is pivoted to the second shaft part. A connecting seat, a pivot and a rotating shaft are arranged on the sole; the central axes of the pivot and the rotating shaft are vertically intersected; the first driving mechanism comprises a first swing arm, a first connecting rod and a first driving piece, the first connecting rod extends along a first straight line, and the first straight line and the central axis of the first shaft part jointly define a first plane; the second driving mechanism comprises a second swing arm, a second connecting rod and a second driving piece, the second connecting rod extends along a second straight line, and the second straight line and the central axis of the second shaft part jointly define a second plane. Abrasion of parts is relieved, the service life of the humanoid robot is prolonged, and power loss is reduced.

Description

Technical Field

[0001] This invention relates to the field of humanoid robot technology, specifically to a lower limb assembly and a humanoid robot. Background Technology

[0002] Humanoid robots are a new type of robot capable of mimicking the shape and movement of the human body, and they have broad development prospects. Similar in structure to the human body, a humanoid robot includes a head, torso, a pair of upper limbs, and a pair of lower limbs. The lower limbs consist of the thigh, calf, and foot. The ankle joint, where the calf connects to the foot, needs to be able to swing up and down as well as side to side. In the lower limb assembly of a humanoid robot, a drive mechanism is typically installed on the calf to achieve the up-and-down and side-to-side swinging at the ankle joint. The drive mechanism is connected to the foot via a swing arm and a linkage. In existing humanoid robots... In the lower limb assembly, due to the installation conditions of the drive mechanism, the connecting rod is usually required to be bent and tilted to connect the swing arm and the foot. For example, the lower limb mechanism of the humanoid robot disclosed in patent document CN118810958A has a bent and tilted connecting rod. When the connecting rod moves, the interaction force generated by the connecting rod pushing or pulling the swing arm and the foot will inevitably produce a certain offset angle with the rotation axis of the connecting rod end, resulting in more severe wear at the connection between the connecting rod and the swing arm and the foot, which affects the service life of the humanoid robot. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the purpose of the present invention is to provide a lower limb assembly and a humanoid robot to solve the problem that the connecting rods that cooperate with the drive mechanism in the prior art are prone to wear.

[0004] The objective of this invention is achieved through the following technical solution: The lower limb assembly includes the lower leg, foot, connector, first drive mechanism, and second drive mechanism; The connector includes a first shaft portion and a second shaft portion connected to the first shaft portion. The central axis of the first shaft portion intersects the central axis of the second shaft portion perpendicularly. The bottom of the lower leg is pivotally connected to the first shaft portion, and the ball of the foot is pivotally connected to the second shaft portion. The foot is provided with a connecting seat, a pivot coaxial with the first axis, and a rotating shaft parallel to and offset from the second axis. The rotating shaft is pivotally connected to the connecting seat so that the rotating shaft can rotate relative to the connecting seat about its own central axis. The pivot is connected to the rotating shaft and the central axis of the pivot intersects the central axis of the rotating shaft perpendicularly. The first drive mechanism includes a first swing arm, a first connecting rod, and a first drive member. One end of the first swing arm is pivotally connected to the lower leg and connected to the output end of the first drive member, so that the first drive member drives the first swing arm to swing relative to the lower leg. The upper end of the first connecting rod is hinged to the other end of the first swing arm, and the lower end is pivotally connected to a pivot. The first connecting rod extends along a first straight line, and the first straight line and the central axis of the first shaft portion together define a first plane. The second drive mechanism includes a second swing arm, a second connecting rod, and a second drive member. One end of the second swing arm is pivotally connected to the lower leg and connected to the output end of the second drive member, so that the second drive member drives the second swing arm to swing relative to the lower leg. The upper end of the second connecting rod is hinged to the other end of the second swing arm, and the lower end is pivotally connected to the second shaft. The second connecting rod extends along a second straight line, and the second straight line and the central axis of the second shaft define a second plane.

[0005] According to an embodiment of the present invention, the first swing arm and the first link of the first drive mechanism form a parallel four-bar linkage with the lower leg and the foot, and the second swing arm and the second link of the second drive mechanism form a parallel four-bar linkage with the lower leg and the foot. The first link and the second link both extend along a straight line. The foot swings in the first plane and swings up and down in the second plane. The first straight line falls in the first plane, and the second straight line falls in the second plane, so that the first link and the second link do not need to be tilted on the outside of the lower leg. The rotation axis at the connection between the first link and the first swing arm and the pivot, and the rotation axis at the connection between the second link and the second swing arm and the second shaft will not have an offset angle, which reduces the wear of the parts, improves the accuracy of the lower limb assembly, and extends the service life of the humanoid robot. Since there is no offset angle at the connection between the link and the swing arm and the foot, the link can efficiently transmit the output power of the drive component, reduce power loss, and improve the endurance of the humanoid robot.

[0006] In a preferred embodiment, a first mounting groove extending along a first direction is provided on the lower leg, the first direction being parallel to the central axis of the second shaft portion. The first driving member is embedded in the first mounting groove and fixedly engaged with the lower leg. A second mounting groove extending along a second direction is provided on the lower leg, the second direction being parallel to the central axis of the first shaft portion. The second driving member is embedded in the second mounting groove and fixedly engaged with the lower leg. Providing mounting grooves on the lower leg provides mounting space for the first and second driving members, avoiding the first and second driving mechanisms from occupying excessive mounting space and preventing large protrusions on the sides of the lower limb assembly, thus making the overall structure of the lower limb assembly more compact. Simultaneously, embedding the first and second driving members within the lower leg minimizes the size of the swing arm and connecting rod, facilitating their arrangement on the lower leg.

[0007] In a preferred embodiment, the first driving component is a first motor, and the first swing arm includes a first segment located at one end of the first motor and connected to the output end of the first motor, and a second segment extending from the first segment toward the center of the first motor's axial direction. The second segment has a pivot portion located directly above a pivot, and the upper end of the first connecting rod is pivotally connected to the pivot portion. By configuring the first swing arm as an L-shape, the connection point between the first swing arm and the first connecting rod extends to or near the center of the first motor's axial direction. This reduces the space occupied by the first driving mechanism in the front-rear direction while ensuring the first connecting rod extends vertically.

[0008] In a preferred embodiment, the second driving component is a second motor, and the second swing arm includes a third segment located at one end of the second motor and connected to the output end of the second motor, and a fourth segment extending from the third segment toward the center of the second motor's axial direction. A rotating seat is provided on the fourth segment above the central axis of the second shaft, and the upper end of the second connecting rod is hinged to the rotating seat. By configuring the second swing arm in an L-shape, the connection point between the second swing arm and the second connecting rod extends to or near the center of the second motor's axial direction. This reduces the space occupied by the second driving mechanism in the left-right direction while ensuring the second connecting rod extends vertically.

[0009] In a preferred embodiment, the connector has two opposing lugs, a pivot is positioned between the two lugs and pivotally engages with them, and the pivot has a through groove extending from its top surface to its bottom surface. A pivot is placed within the through groove, with its two ends connected to the side walls of the through groove. The lower end of the first connecting rod is placed within the through groove and pivotally fitted onto the pivot. During assembly, the lower end of the first connecting rod can be inserted into the through groove, aligning a pre-drilled hole on the lower end of the first connecting rod with a hole on the side wall of the through groove. Then, the pivot is inserted from one side of the pivot, passing through the hole at the lower end of the first connecting rod and the holes on the side walls of the through groove, thus facilitating the connection between the first connecting rod and the pivot. A cross-shaped axle component is formed by a rotating shaft and a pivot, connecting the foot and the first link. The first drive mechanism can move in the first plane, causing the foot to swing sideways in the left and right directions. At the same time, the first link can adaptively swing back and forth around the pivot. When the second drive mechanism causes the foot to swing up and down in the front and back directions, the first link can adaptively follow the pivot, avoiding interference of the first link with the up and down swing of the foot.

[0010] In a preferred embodiment, two opposing connecting ears are provided on the sole of the foot. A second shaft is positioned between the two connecting ears and pivotally engages with them, allowing the sole of the foot to swing relative to the second shaft around its central axis. One end of the second shaft extends into a shaft head, which has a clearance groove extending from its top surface to its bottom surface. A connecting shaft is disposed within the clearance groove, with both ends of the connecting shaft connected to the side walls of the clearance groove. The lower end of a second connecting rod is positioned within the clearance groove and pivotally fitted onto the connecting shaft. During assembly, the lower end of the second connecting rod is inserted into the clearance groove, aligning the hole at the lower end of the second connecting rod with pre-set holes on the side walls of the clearance groove. The connecting shaft is then passed horizontally from one side of the shaft head to the pre-set hole on the shaft head and the hole at the lower end of the second connecting rod, thus facilitating the connection between the second connecting rod and the second shaft. By extending the shaft head on the second shaft, the lower end of the second link is offset from the central axis of the first shaft by a certain distance. In the parallel four-bar linkage composed of the second swing arm, the second link, the foot, and the lower leg, the second swing arm has sufficient size, so that the foot has a large vertical swing range within the limited swing range of the second swing arm, in order to meet the usage requirements of the humanoid robot in different scenarios.

[0011] In a preferred embodiment, both the first and second connecting rods have circular cross-sections, and the diameters of both cross-sections gradually decrease from the middle to both ends along their length. Because the cross-sections of the first and second connecting rods are regular circles, they are easy to manufacture. Furthermore, by designing them with gradually changing cross-sectional dimensions, their mid-length portion exhibits high bending strength. This minimizes their weight while meeting usage requirements, thereby reducing the overall weight of the lower limb assembly.

[0012] In a preferred embodiment, the lower leg is encased in an outer shell, which includes a first shell and a second shell fixed to both sides of the lower leg. The bottom of the first shell is located between the connector and the connecting seat. The bottom of the lower leg and the bottom of the first shell each form a connecting portion, which are opposite each other. A first shaft is placed between the two connecting portions and pivotally engages with them. During assembly, the second shaft of the connector is connected to the foot. The connecting portions and the connecting parts are respectively connected from both sides of the connector to the two ends of the first shaft. The first shell and the lower leg are fixed together with bolts, so that the bottom of the lower leg is connected to the foot through the connector. The connecting seat is placed outside the connecting portion at the bottom of the first shell, offset from the middle position in the width direction of the foot. There is a certain distance between the pivot and the connector. In the parallel four-bar linkage composed of the first swing arm, the first link, the foot, and the lower leg, the first swing arm has sufficient size, so that the foot has a large left and right swing amplitude within the limited swing range of the first swing arm, to meet the usage requirements of the humanoid robot in different scenarios.

[0013] In a preferred embodiment, the outer casing is provided with a first clearance hole and a second clearance hole. The upper end of the first connecting rod is hinged to the first swing arm at the first clearance hole, and the upper end of the second connecting rod is hinged to the second swing arm at the second clearance hole. The first clearance hole facilitates the connection between the first swing arm and the upper end of the first connecting rod, and also provides space for the first swing arm to move. The second clearance hole facilitates the connection between the swing arm and the upper end of the second connecting rod, and also provides space for the second swing arm to move.

[0014] Humanoid robot, including the aforementioned lower limb components.

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the installation of the present invention; Figure 3 for Figure 2 A schematic diagram showing the connection between the first drive mechanism, the second drive mechanism, and the foot. Figure 4 for Figure 2 A schematic diagram of the midfoot structure; Figure 5 for Figure 2 Schematic diagram of the middle connector; Figure 6 This is a schematic diagram of one working state of the present invention; Figure 7 This is a schematic diagram of another working state of the present invention.

[0017] In the diagram: 10. Lower leg; 101. First mounting slot; 102. Second mounting slot; 11. Connecting part; 20. Foot; 21. Connecting seat; 211. Ear; 22. Pivot; 23. Rotating shaft; 231. Through groove; 24. Connecting ear; 30. Connecting piece; 31. First shaft; 32. Second shaft; 33. Shaft head; 331. Clearance groove; 34. Connecting shaft; 41. First driving member; 42. First swing arm; 421. First section; 422. Second section; 423. Pivot part; 43. First connecting rod; 51. Second driving member; 52. Second swing arm; 521. Third section; 522. Fourth section; 523. Rotating seat; 53. Second connecting rod; 60. Outer shell; 601. First clearance hole; 602. Second clearance hole; 61. First housing; 611. Connecting part; 62. Second housing. Detailed Implementation

[0018] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Unless otherwise specified, the materials and equipment used in this embodiment are commercially available. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0019] In the description of this application, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In the description of this application, "a plurality of" means two or more, unless otherwise precisely specified.

[0020] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected," "linked," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a connection through an intermediary, or a connection within two elements or an interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus.

[0022] Please refer to Figure 1-7As shown, this invention provides a lower limb assembly for a humanoid robot, comprising a lower leg 10, a foot 20, a connector 30, a first drive mechanism, and a second drive mechanism. The connector 30 connects the lower leg 10 and the foot 20, allowing the lower leg 10 and the foot 20 to rotate relative to each other around two perpendicularly intersecting axes. The connector 30 specifically includes a first shaft portion 31 and a second shaft portion 32. The central axis O2 of the second shaft portion 32 intersects perpendicularly with the central axis O1 of the first shaft portion 31. The lower leg 10 is a rigid member, with its lower end pivotally connected to the first shaft portion 31, allowing the lower leg 10 to swing relative to the connector 30 around the central axis O1 of the first shaft portion 31. The foot 20 is pivotally connected to the second shaft portion 32, allowing the foot 20 to swing relative to the connector 30 around the central axis of the second shaft portion 32. The first shaft portion 31 and the second shaft portion 32 intersect perpendicularly, forming a cross-shaped axle component with the connector 30. In some embodiments, the first shaft portion 31 and the second shaft portion 32 are integrally formed components.

[0023] The foot 20 is provided with a connecting seat 21, a pivot 22, and a rotating shaft 23. The connecting seat 21 is offset from the middle position in the width direction of the foot 20. The rotating shaft 23 is pivotally connected to the connecting seat 21 so that the rotating shaft 23 can rotate relative to the connecting seat 21 around its own central axis O3. The pivot 22 is coaxial with the first shaft part 31. That is, the central axis O1 is the common central axis of the pivot 22 and the first shaft part 31. The pivot 22 is connected to the rotating shaft 23 so that the central axis O1 of the pivot 22 intersects the central axis O3 of the rotating shaft 23 perpendicularly, thereby making the pivot 22 and the rotating shaft 23 form a cross shaft component. The extension direction of the central axis O1 is consistent with the left and right direction, and the extension direction of the central axis O2 is consistent with the front and back direction. The first drive mechanism is used to provide power for the rotation of the foot 20 around the central axis O2 relative to the lower leg 10, so that the foot 20 swings to the left and right direction. The second drive mechanism is used to provide power for the rotation of the foot 20 around the central axis O1 relative to the lower leg 10, so that the foot 20 swings up and down in the front and back direction, thereby simulating the two swing degrees of freedom at the human ankle joint.

[0024] The first drive mechanism includes a first swing arm 42, a first link 43, and a first drive member 41. The first drive member 41 is mounted on the lower leg 10. One end of the first swing arm 42 is pivotally connected to the lower leg 10 and connected to the output end of the first drive member 41. The first drive member 41 can drive the first swing arm 42 to swing relative to the lower leg 10. The upper end of the first link 43 is hinged to the other end of the first swing arm 42, and the lower end of the first link 43 is pivotally connected to the pivot 22. The first link 43 extends along a first straight line L1. The first straight line L1 and the central axis O1 of the first shaft 31 together define a first plane A. In the first plane A, the first swing arm 42, the first link 43, the foot 20, and the lower leg 10 constitute a parallel four-bar linkage. The first swing arm 42, as the active part of the parallel four-bar linkage, drives the foot 20, as the driven part, to swing laterally in the left and right directions.

[0025] The second drive mechanism is the same as the first drive mechanism, including a second swing arm 52, a second link 53, and a second drive member 51. The second drive member 51 is mounted on the lower leg 10. One end of the second swing arm 52 is pivotally connected to the lower leg 10 and connected to the output end of the second drive member 51. The second drive member 51 can drive the second swing arm 52 to swing relative to the lower leg 10. The upper end of the second link 53 is hinged to the other end of the second swing arm 52, and the lower end of the second link 53 is pivotally connected to the second shaft 32. The second link 53 extends along the second straight line L2. The second straight line L2 and the central axis O2 of the second shaft 32 together define a second plane B. In this second plane, the second swing arm 52, the second link 53, the foot 20, and the lower leg 10 constitute a parallel four-bar linkage. The second swing arm 52, as the active part of the parallel four-bar linkage, drives the foot 20, as the driven part, to swing up and down in the front-back direction.

[0026] See Figure 6 and Figure 7The first swing arm 42 and the first link 43 of the first drive mechanism form a parallel four-bar linkage with the lower leg 10 and the foot 20. The second swing arm 52 and the second link 53 of the second drive mechanism also form a parallel four-bar linkage with the lower leg 10 and the foot 20. The first link 43 extends along the first straight line L1, and the second link 53 extends along the second straight line L2. Both the first link 43 and the second link 53 extend along straight lines. The foot 20 swings within the first plane A and oscillates up and down within the second plane B. The first straight line L1 falls within the first plane A, and the second straight line L2 falls within the second plane B. The first link 43 and the second link 53 do not need to be tilted on the outside of the lower leg 10. The rotation axis at the connection between the first link 43 and the first swing arm 42 and the pivot 22, and the rotation axis at the connection between the second link 53 and the second swing arm 52 and the second shaft 32 will not have any offset angle. This reduces the wear of the parts, improves the precision of the lower limb assembly, and extends the service life of the humanoid robot. Since there is no offset angle at the connection between the link and the swing arm and the foot, the link can efficiently transmit the output power of the drive component, reduce power loss, and improve the endurance of the humanoid robot.

[0027] In a preferred embodiment, the present invention provides a first mounting groove 101 on the lower leg 10, the first mounting groove 101 extending along a first direction, the first direction being parallel to the central axis O2 of the second shaft portion 32, that is, the first direction being consistent with the front-rear direction, the first driving member 41 being embedded in the first mounting groove 101 and fixedly engaged with the lower leg 10; a second mounting groove 102 is also provided on the lower leg 10, the second mounting groove 102 extending along a second direction, the second direction being parallel to the central axis of the first shaft portion 31, that is, the second direction being consistent with the left-right direction, the second driving member 51 being embedded in the second mounting groove 102 and fixedly engaged with the lower leg 10. An installation groove is provided on the lower leg 10 to provide installation space for the first drive member 41 and the second drive member 51, so as to avoid the first drive mechanism and the second drive mechanism occupying a large installation space and avoid the lower limb assembly having a large protruding part on the side, making the overall structure of the lower limb assembly more compact; at the same time, the first drive member 41 and the second drive member 51 are embedded inside the lower leg 10 to minimize the size of the swing arm and the connecting rod, and facilitate the arrangement of the swing arm and the connecting rod on the lower leg 10.

[0028] The first driving component 41 mentioned above is a first motor. The first mounting groove 101 extends in the front-rear direction, and the first motor is embedded in the first mounting groove 101 with its axial direction consistent with the front-rear direction. The first swing arm 42 is configured as an L-shape. Specifically, the first swing arm 42 includes a first segment 421 and a second segment 422. The first segment 421 is located at the front end of the first motor and is connected to the output end located at the front end of the first motor. The second segment 422 extends from the first segment 421 toward the middle of the axial direction of the first motor. A pivot part 423 is provided on the second segment 422, located directly above the pivot 22. The upper end of the first connecting rod 43 is pivotally connected to the pivot part 423. By configuring the first swing arm 42 as an L-shape, the position where the first swing arm 42 connects to the first connecting rod 43 extends to or near the middle of the axial direction of the first motor. This reduces the space occupied by the first driving mechanism in the front-rear direction while allowing the first connecting rod 43 to extend in the vertical direction.

[0029] Similar to the above, the second driving component 51 is a second motor, and the second mounting groove 102 extends in the left-right direction. The second motor is embedded in the second mounting groove 102, and its axial direction is consistent with the left-right direction. The second swing arm 52 is configured as an L-shape. Specifically, the second swing arm 52 includes a third segment 521 and a fourth segment 522. The third segment 521 is located at one end of the second motor and is connected to the output end located at one end of the second motor. The fourth segment 522 extends from the third segment 521 toward the center of the second motor in the circumferential direction. A rotating seat 523 is provided on the fourth segment 522, located directly above the central axis O2 of the second shaft portion 32. The upper end of the second connecting rod 53 is hinged to the rotating seat 523. By configuring the second swing arm 52 as an L-shape, the position where the second swing arm 52 connects to the second connecting rod 53 extends to or near the center of the second motor's axial direction. While extending the second connecting rod 53 in the vertical direction, the space occupied by the second driving mechanism in the left-right direction is reduced.

[0030] In this invention, the first driving member 41 and the second driving member 51 are not limited to motors; they can also be other driving members that can drive the first swing arm 42 and the second swing arm 52 to swing.

[0031] For ease of assembly, two front-to-back opposing ears 211 are provided on the connecting seat 21. The pivot 23 is placed between the two ears 211 and pivotally engages with the two ears 211. The pivot 23 is provided with a through groove 231 extending from its top surface to its bottom surface. The through groove 231 is configured to have sufficient size in the front-to-back direction to allow the bottom of the first connecting rod 43 to be embedded and to allow the first connecting rod 43 to swing back and forth inside it. The pivot 22 is placed in the through groove 231, and the two ends of the pivot 22 are respectively connected to the two side walls of the through groove 231. The lower end of the first connecting rod 43 is embedded in the through groove 231, and the lower end of the first connecting rod 43 is sleeved on the pivot 22 and pivotally engages with the pivot 22.

[0032] During assembly, the lower end of the first connecting rod 43 can be embedded in the through groove 231, aligning the pre-set hole on the lower end of the first connecting rod 43 with the hole on the side wall of the through groove 231. Then, the pivot 22 is inserted from one side of the rotating shaft 23, passing through the hole at the lower end of the first connecting rod 43 and the holes on both sides of the through groove 231, thus facilitating the connection between the first connecting rod 43 and the pivot 22. The pivot 22 can be fixed to the rotating shaft 23 by bolts. In some other embodiments, a bolt passing through the rotating shaft 23 can be used directly as the pivot 22. The pivot 23 is pivotally connected between the two ears 211, and the pivot 22 passes through the pivot 23. Thus, the pivot 23 and the pivot 22 form a cross-axis component connecting the foot 20 and the first link 43. The first drive mechanism can move in the first plane A, causing the foot 20 to swing sideways in the left and right directions. At the same time, the first link 43 can adaptively swing back and forth around the pivot 22. When the second drive mechanism causes the foot 20 to swing up and down in the back and forth direction, the first link 43 can adaptively follow the pivot 22, avoiding interference of the first link 43 with the up and down swing of the foot 20.

[0033] To facilitate the connection of the connector 30 to the foot 20, two front-to-back connecting ears 24 are provided on the foot 20. The second shaft 32 is placed between the two connecting ears 24, and both ends of the second shaft 32 are pivotally connected to the two connecting ears 24 respectively, so that the foot 20 can swing relative to the second shaft 32 around the central axis O2 of the second shaft 32. A shaft head 33 protruding from the front connecting ear 24 extends from the front end of the second shaft 32. A clearance groove 331 extending from its top surface to its bottom surface is provided on the shaft head 33. A connecting shaft 34 is provided in the clearance groove 331. Both ends of the connecting shaft 34 are connected to the side wall of the clearance groove 331 respectively. The lower end of the second connecting rod 53 is embedded in the clearance groove 331, and its lower end is sleeved on the connecting shaft 34 and pivotally engaged with the connecting shaft 34. The clearance groove 331 is set to have sufficient size in the front-to-back direction so that the second connecting rod 53 can swing back and forth inside it.

[0034] During assembly, the lower end of the second connecting rod 53 is inserted into the clearance groove 331, aligning the hole at the lower end of the second connecting rod 53 with the pre-set holes on both sides of the clearance groove 331. The connecting shaft 34 is then passed horizontally from one side of the shaft head 33 to the pre-set hole on the shaft head 33 and the hole at the lower end of the second connecting rod 53, thus facilitating the connection between the second connecting rod 53 and the second shaft portion 32. Through the shaft head 33 extending from the second shaft portion 32, the lower end of the second connecting rod 53 is offset from the central axis O1 of the first shaft portion 31 by a certain distance. In the parallel four-bar linkage composed of the second swing arm 52, the second connecting rod 53, the foot 20, and the lower leg 10, the second swing arm 52 has sufficient dimensions, allowing the foot 20 to have a large vertical swing amplitude within the limited swing range of the second swing arm 52, thus meeting the usage requirements of the humanoid robot in different scenarios.

[0035] In this invention, since both the first link 43 and the second link 53 are configured to extend in a straight line and do not need to be configured to be inclined, the first link 43 and the second link 53 can adopt some regular cross-sections. For example, the cross-sections of the first link 43 and the second link 53 are both configured to be circular, and the diameter of the cross-sections of the first link 43 and the second link 53 gradually decreases from the middle of their length direction to both ends. Since the cross-sections of the first link 43 and the second link 53 are regular circles, the first link 43 and the second link 53 are easy to process and manufacture. Furthermore, by configuring them with a gradually changing cross-sectional size, the bending strength of the middle of their length direction is high. Under the premise of meeting the usage requirements, the weight of the two links is reduced as much as possible, thereby reducing the self-weight of the entire lower limb assembly.

[0036] In other embodiments, the cross-sections of the first link 43 and the second link 53 may also be set to other regular shapes that are easy to process, such as square, ellipse, etc.

[0037] To make the anthropomorphic shape of the lower limb components more realistic, an outer shell 60 is wrapped around the lower leg 10. The shape of the outer shell 60 is consistent with the surface shape of the human lower leg. It includes a first shell 61 and a second shell 62 fixed on both sides of the lower leg 10. The bottom of the first shell 61 is located between the connector 30 and the connecting seat 21. A connecting part 11 is provided at the bottom of the lower leg 10. The connecting part 611 is provided at the bottom of the first shell 61. The connecting part 11 and the connecting part 611 are arranged opposite to each other. A first shaft part 31 is placed between the connecting part 11 and the connecting part 611, and the two ends of the first shaft part 31 are pivotally connected to the connecting part 11 and the connecting part 611 respectively.

[0038] During assembly, the second shaft portion 32 of the connector 30 is connected to the foot 20. The connecting portion 11 and the connecting portion 611 are respectively connected from both sides of the connector 30 to the two ends of the first shaft portion 31. The first housing 61 and the lower leg 10 are fixed together with bolts, so that the bottom of the lower leg 10 is connected to the foot 20 through the connector 30. The connecting seat 21 is placed outside the connecting portion 611 at the bottom of the first housing 61. The connecting seat 21 is offset from the middle position in the width direction of the foot 20. There is a certain gap between the rotating shaft 23 and the connector 30. In the parallel four-bar linkage composed of the first swing arm 42, the first connecting rod 43, the foot 20 and the lower leg 10, the first swing arm 42 has sufficient size, so that the foot 20 has a large left and right swing amplitude within the limited swing range of the first swing arm 42, so as to meet the usage requirements of the humanoid robot in different scenarios.

[0039] The outer casing 60 is provided with a first clearance hole 601 and a second clearance hole 602. The upper end of the first connecting rod 43 is hinged to the first swing arm 42 at the first clearance hole 601. Specifically, the pivot part 423 on the first swing arm 42 extends to the first clearance hole 601 to facilitate connection with the upper end of the first connecting rod 43, and the first clearance hole 601 provides space for the first swing arm 42 to move. The upper end of the second connecting rod 53 is hinged to the second swing arm 52 at the second clearance hole 602. Specifically, the swivel seat 523 on the second swing arm 52 extends to the second clearance hole 602 to facilitate connection with the upper end of the second connecting rod 53, and the second clearance hole 602 provides space for the second swing arm 52 to move.

[0040] The humanoid robot of the present invention includes the lower limb assembly described above. Other structures of the humanoid robot are the same as those in the prior art and will not be described in detail here.

[0041] Although only certain components and embodiments of this application have been illustrated and described, many modifications and alterations will be apparent to those skilled in the art without actually departing from the scope and spirit of the claims, such as variations in the size, dimensions, structure, shape and proportion of the various elements, installation arrangement, material use, color, orientation, etc.

[0042] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the embodiments of the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A lower leg assembly characterized by, Includes the lower leg, foot, connecting parts, first drive mechanism, and second drive mechanism; The connector includes a first shaft portion and a second shaft portion connected to the first shaft portion. The central axis of the first shaft portion intersects the central axis of the second shaft portion perpendicularly. The bottom of the lower leg is pivotally connected to the first shaft portion, and the ball of the foot is pivotally connected to the second shaft portion. The foot is provided with a connecting seat, a pivot coaxial with the first axis, and a rotating shaft parallel to and offset from the second axis. The rotating shaft is pivotally connected to the connecting seat so that the rotating shaft can rotate relative to the connecting seat about its own central axis. The pivot is connected to the rotating shaft and the central axis of the pivot intersects the central axis of the rotating shaft perpendicularly. The first drive mechanism includes a first swing arm, a first connecting rod, and a first drive member. One end of the first swing arm is pivotally connected to the lower leg and connected to the output end of the first drive member, so that the first drive member drives the first swing arm to swing relative to the lower leg. The upper end of the first connecting rod is hinged to the other end of the first swing arm, and the lower end is pivotally connected to a pivot. The first connecting rod extends along a first straight line, and the first straight line and the central axis of the first shaft portion together define a first plane. The second drive mechanism includes a second swing arm, a second connecting rod, and a second drive member. One end of the second swing arm is pivotally connected to the lower leg and connected to the output end of the second drive member, so that the second drive member drives the second swing arm to swing relative to the lower leg. The upper end of the second connecting rod is hinged to the other end of the second swing arm, and the lower end is pivotally connected to the second shaft. The second connecting rod extends along a second straight line, and the second straight line and the central axis of the second shaft define a second plane.

2. The lower extremity assembly of claim 1, wherein, The lower leg is provided with a first mounting groove extending in a first direction, which is parallel to the central axis of the second shaft portion. A first driving member is embedded in the first mounting groove and fixedly engaged with the lower leg. The lower leg is provided with a second mounting groove extending in a second direction, which is parallel to the central axis of the first shaft portion. A second driving member is embedded in the second mounting groove and fixedly engaged with the lower leg.

3. The lower extremity assembly of claim 2, wherein, The first driving component is a first motor. The first swing arm includes a first section located at one end of the first motor and connected to the output end of the first motor, and a second section extending from the first section toward the center of the first motor axis. A pivot part is provided on the second section located directly above the pivot. The upper end of the first connecting rod is pivotally connected to the pivot part.

4. The lower extremity assembly of claim 2, wherein, The second driving component is a second motor. The second swing arm includes a third section located at one end of the second motor and connected to the output end of the second motor, and a fourth section extending from the third section toward the center of the second motor axis. A rotating seat is provided on the fourth section located above the central axis of the second shaft. The upper end of the second connecting rod is hinged to the rotating seat.

5. The lower extremity assembly of claim 1, wherein, The connector has two opposing ears. The pivot is placed between the two ears and pivotally engages with them. The pivot has a through groove extending from its top surface to its bottom surface. The pivot is placed in the through groove and its two ends are respectively connected to the two side walls of the through groove. The lower end of the first connecting rod is placed in the through groove and is pivotally engaged with the pivot.

6. The lower limb assembly as claimed in claim 1, characterized in that, Two opposing connecting ears are provided on the ball of the foot. The second shaft is placed between the two connecting ears and pivotally engages with the two connecting ears so that the ball of the foot can swing relative to the second shaft about the central axis of the second shaft. One end of the second shaft extends into a shaft head, and the shaft head is provided with a clearance groove extending from its top surface to its bottom surface. A connecting shaft is provided in the clearance groove. The two ends of the connecting shaft are respectively connected to the two side walls of the clearance groove. The lower end of the second connecting rod is placed in the clearance groove, and the lower end of the second connecting rod is pivotally fitted onto the connecting shaft.

7. The lower limb assembly as claimed in claim 1, characterized in that, Both the first and second links have circular cross-sections, and the diameters of both cross-sections gradually decrease from the middle of their length towards both ends.

8. The lower limb assembly as claimed in claim 1, characterized in that, The lower leg is covered by an outer shell, which includes a first shell and a second shell fixed to both sides of the lower leg. The bottom of the first shell is located between the connector and the connecting seat. The bottom of the lower leg and the bottom of the first shell form a connecting part, which are opposite to each other. The first shaft is placed between the two connecting parts and pivotally engages with the two connecting parts.

9. The lower limb assembly as claimed in claim 8, characterized in that, The outer casing is provided with a first clearance hole and a second clearance hole. The upper end of the first connecting rod is hinged to the first swing arm at the first clearance hole, and the upper end of the second connecting rod is hinged to the second swing arm at the second clearance hole.

10. A humanoid robot, characterized in that, Includes the lower limb assembly as described in any one of claims 1-9.

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