Bionic wheel-foot leg structure and wheel-foot robot

Abstract

The present invention provides a bionic wheel-foot leg structure and a wheel-foot robot, wherein the bionic wheel-foot leg structure includes: a shank connecting rod, a linear drive, and a foot-end unit, wherein the foot-end unit includes: a wheel, a drive motor, a wrist joint, and a shank base, wherein the drive motor is fixed to a first side of the wrist joint, the drive motor transmission end is connected to the wheel, the shank base is connected to a rotating shaft of the wrist joint, and a rudder bar extends outward from the second side of the wrist joint, wherein the first end of the shank connecting rod extends outward from a bracket, the first end of the linear drive is hinged to the shank connecting rod bracket via a first rotating joint, and the second end is hinged to the rudder bar via a second rotating joint, and the second end of the shank connecting rod is connected to the shank base. In this way, the rotation and swing of the wheel foot can be achieved by imitating the design of the radial and ulnar rotating wrist joint, thereby improving the flexibility of the wheel-foot leg structure.

Description

Technical Field

[0001] The present invention relates to robotics technology, in particular to a bionic wheel-foot leg structure and a wheel-foot type robot. Background Art

[0002] Existing wheeled-legged robots have two main design configurations for their leg structures. The first utilizes no rotating bare joints, meaning the bare joints at the end of the leg can only move forward and backward. The second utilizes a direct motor connection, where the motor's rotation enables the bare joints to rotate. However, the inventors discovered that both designs present certain challenges when achieving overall robot steering.

[0003] For example, the first design doesn't use any rotating bare joints. Since the leg ends can only move forward and backward, the robot's steering can only be achieved by rotating the shoulder joints. This complicates the kinematic algorithms and requires more precise control of the robot, making it more difficult. Furthermore, this design structure presents a problem: if the robot encounters an obstacle while walking, it will not be able to adjust the wheel direction by rotating the bare joints to circumvent the obstacle, further limiting the flexibility of the wheel-legged robot's leg structure.

[0004] As for the mode that uses direct motor connection, although the rotation of the end bare joint can be achieved, the direct motor connection structure will make the end of the leg very heavy and large, and the torque of the motor will also need to be large, which is not conducive to the robot's leg lifting action and the lightweight and miniaturization of the overall device, making the leg structure less flexible and also not conducive to the coordinated design of the robot's overall structure. Summary of the Invention

[0005] To this end, the main purpose of the present invention is to provide a bionic wheel-foot leg structure and a wheel-foot robot, so as to realize the rotation and swing of the wheel foot by imitating the design of the radial and ulnar rotating wrist joint, so as to improve the flexibility of the wheel-foot leg structure.

[0006] In order to achieve the above-mentioned purpose, according to the first aspect of the present invention, a bionic wheel-foot leg structure is provided, which includes: a calf connecting rod, a linear drive, and a foot-end unit, wherein the foot-end unit includes: a wheel, a drive motor, a wrist joint, and a calf base, wherein the drive motor is fixed on the first side of the wrist joint, the drive motor transmission end is connected to the wheel, the calf base is connected to the wrist joint shaft, and the second side of the wrist joint extends outward to form a rudder bar, wherein the first end of the calf connecting rod extends outward to form a bracket, the first end of the linear drive is hinged to the calf connecting rod bracket via the first rotating joint, and the second end is hinged to the rudder bar via the second rotating joint, and the second end of the calf connecting rod is connected to the calf base.

[0007] In a possible preferred embodiment, the wrist joint is provided with a first axial hole, and a keyway is provided in the first axial hole, the calf base is provided with a second axial hole, and the calf base and the wrist joint are connected by a rotating shaft through an anti-loosening shaft inserted into the first and second axial holes, wherein the anti-loosening shaft is provided with a flat key to match with the keyway in the first axial hole of the wrist joint to fix the axial position of the anti-loosening shaft, and the top cover of the second axial hole of the calf base is provided with an angle sensor, and its sensing area faces the top of the anti-loosening shaft.

[0008] In a possible preferred embodiment, a bearing groove is provided at either the first axial hole of the wrist joint or the second axial hole of the calf base to accommodate a thrust bearing, and the wrist joint and the calf base pass through the thrust bearing via an anti-loosening shaft and are inserted into the first and second axial holes to form a rotating shaft connection.

[0009] In a possible preferred embodiment, the first rotating joint comprises: a first joint and a second joint, wherein the first joint is Z-shaped, with a first longitudinal axis fork provided on its first side and the second side fixed on the bracket, and the second joint is U-shaped fork-shaped, with a longitudinal axis hole provided on its concave side and a transverse axis hole provided near the fork head, the second joint is connected to the first longitudinal axis fork rotating shaft of the first joint via the longitudinal axis hole, and the fork head of the second joint is connected to the first end rotating shaft of the linear drive via the transverse axis hole to establish a two-degree-of-freedom hinge between the linear drive and the calf connecting rod.

[0010] In a possible preferred embodiment, the second rotational joint component includes: a third joint and a fourth joint, wherein the third joint is in a U-shaped fork shape, a longitudinal axis hole is provided on its concave side, and a transverse axis hole is provided near the fork head, and a second longitudinal axis fork and a third longitudinal axis fork are provided at both ends of the fourth joint, and the second longitudinal axis fork and the third longitudinal axis fork are inclined, the fourth joint component is connected to the third joint longitudinal axis hole rotating shaft via the second longitudinal axis fork, the fourth joint component is connected to the rudder shaft via the third longitudinal axis fork, and the third joint is connected to the second end rotating shaft of the linear drive via the transverse axis hole at the fork head to establish a three-degree-of-freedom hinge between the linear drive and the rudder shaft.

[0011] In a possible preferred embodiment, the bionic wheel-foot leg structure further includes: a joint motor group, a crank four-bar linkage, wherein the crank four-bar linkage includes: a thigh link, a thigh auxiliary link, a driving link, and a knee joint link, the first ends of the thigh link and the thigh auxiliary link are respectively connected to the end motor stator of the joint motor group, the driving link is connected to the end motor rotor of the joint motor group, the first end of the knee joint link is connected to the crank shaft of the driving link, and the second ends of the thigh link, the thigh auxiliary link, and the knee joint link are respectively connected to the shaft at the corresponding position of the third end of the calf link.

[0012] In a possible preferred embodiment, the joint motor group includes: a first hip joint motor, a second hip joint motor, a second hip mounting seat, a knee mounting seat, and a knee joint motor. The second hip mounting seat is connected to the stator of the second hip joint motor on the lateral side and to the rotor of the first hip joint motor on the longitudinal side. The stator of the knee joint motor is connected to the rotor of the second hip joint motor via the knee mounting seat. The first ends of the thigh connecting rod and the thigh auxiliary connecting rod are respectively connected to the stator of the knee joint motor, and the driving connecting rod is connected to the rotor of the knee joint motor.

[0013] In a possible preferred embodiment, the joint motor group further includes: a shock absorber, which includes: a mounting ring, a support member, and a spring, wherein the spring is fixed to one side of the mounting ring via the support member, and the mounting ring is connected to the first end of the thigh connecting rod. When the joint motor group drives the crank four-bar linkage to perform a knee-flexing and prone movement to approximately the limit, the spring and the calf connecting rod are offset.

[0014] In order to achieve the above-mentioned purpose, according to the second aspect of the present invention, a wheel-footed robot is further provided, which comprises: a wheel-footed leg composed of any of the above-mentioned bionic wheel-footed leg structures, and a frame, wherein the frame is used to install the wheel-footed leg.

[0015] In a possible preferred embodiment, there are four wheel-foot legs, including two front legs and two rear legs, wherein the front legs and the rear legs have the same structure and are arranged in a front elbow and rear knee style.

[0016] The bionic wheel-foot leg structure and wheel-foot robot provided by the present invention cleverly realize the bionic structure of the wrist joint through only six mechanical components (calf connecting rod, linear drive, calf base, wrist joint component, first and second rotational joint components), thereby simulating the internal rotation and external rotation of the ulna and radius of a living being to support the wheel-foot rotation angle range from -60 degrees to +60 degrees, thereby greatly improving the flexibility of the wheel-foot leg structure.

[0017] On the other hand, the design of this bionic wheel-foot leg structure makes it possible to use a linear drive to simulate the effects of the pronator and supinator muscles. Compared with existing solutions that require complex control algorithms, this solution can directly control the extension and contraction of the linear drive to achieve and establish a control relationship with the left and right rotation and swing of the wrist joint. The operation is more convenient and conducive to achieving more precise motion control of the robot. Moreover, since this structure does not require the use of a motor, it also improves the miniaturization and lightweightness of the wheel-foot leg structure compared to existing technologies, and further reduces the implementation cost.

[0018] In addition, when the bionic wheel-foot leg structure is applied to a multi-legged wheel-foot robot, the steering function of wheeled motion can be realized, which is beneficial to avoid the friction generated during differential driving and improve the service life and reliability of the wheel-foot part. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0020] Figure 1 Schematic diagram of the linkage structure of the bionic wheel-foot leg structure of the present invention when the linear actuator is in a contracted state;

[0021] Figure 2 Schematic diagram of the linkage structure of the linear actuator in the bionic wheel-foot leg structure of the present invention in an extended state;

[0022] Figure 3 This is a schematic diagram of the decomposition of the lower leg structure of the bionic wheel-foot leg structure of the present invention;

[0023] Figure 4 This is a schematic diagram of the structure of the bones in the human arm and wrist when the wrist rotates;

[0024] Figures 5 and 6 This is a schematic diagram of the structure of the bionic wheeled foot leg structure of the present invention, in which the thigh and calf parts are linked, wherein the wheel rotation control of the calf part can be independent of the control of the thigh part;

[0025] Figure 7 This is a schematic diagram of the exploded structure of the thigh portion of the bionic wheel-foot leg structure of the present invention;

[0026] Figure 8 Schematic diagram of the bionic wheel-foot leg structure of the present invention in standing and lying with knees bent;

[0027] Figure 9 This is a schematic structural diagram of a wheel-foot robot that adopts the bionic wheel-foot leg structure of the present invention.

[0028] Description of Reference Numerals

[0029] Joint motor group 1, calf link 2, bracket 21, linear drive 3, foot end unit 4, wheel 41, first joint 5, second joint 6, third joint 7, fourth joint 8, wrist joint 9, rudder bar 91, drive motor 10, small wheel connector 11, calf base 12, thrust bearing 13, anti-loosening shaft 14, angle sensor 15, first rotary joint 80, second rotary joint 81, crank four-bar linkage 20, thigh link 21, thigh auxiliary link 22, drive link 23, knee joint link 24, crank 25, hip joint first motor 26, hip joint second motor 27, hip second mounting seat 28, knee mounting seat 29, knee joint motor 30, mounting ring 31, support 32, spring 33, frame 50, wheel foot leg 51. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0033] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, or are the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance. The terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0034] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0035] In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "layout", "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances and in combination with the existing technology. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other unless there is a conflict. And one or more of the components in the diagram may be necessary or non-essential, and the relative positional relationship between the components in the above diagram can be adjusted according to actual needs.

[0036] In addition, since this case involves bionic structural design, it involves the mixing or replacement of different bionic parts. For example, this case involves the design of a robot foot, but its ankle joint is actually constructed using the structure of the bionic human wrist joint. Therefore, the ankle joint or wrist joint referred to in this case can be understood based on actual conditions without any restriction or definition.

[0037] See also Figures 1 to 4 As shown, in order to imitate the radial and ulnar rotation wrist joint to realize the rotation and swing of the wheel foot, the present invention provides a bionic wheel foot leg structure, wherein the calf part includes: a calf connecting rod 2, a linear drive 3, and a foot end unit 4, wherein the foot end unit 4 includes: a wheel 41, a drive motor 10, a wrist joint 9, and a calf base 12, wherein the drive motor 10 is fixed to the first side of the wrist joint 9, and the drive end of the drive motor 10 can be directly connected to the wheel 41, or matched with the wheel through the wheel connecting member 11, the calf base 12 is connected to the rotating shaft of the wrist joint 9 from the top, and a rudder bar 91 extends outward from the second side of the wrist joint 9, wherein the first end of the calf connecting rod 2 extends outward to form a bracket 21, wherein the bracket 21 is shaped as follows Figure 2 As shown, the example is in a roughly triangular shape. The purpose of this design is to protect the linear drive 3 on the inside from the outside, similar to protecting muscles through bones, so as to achieve a protective effect.

[0038] Furthermore, the first end of the linear drive 3 is hinged to the calf link 2 bracket 21 via the first rotary joint 80 , and the second end is hinged to the rudder bar 91 via the second rotary joint 81 . The second end of the calf link 2 is connected to the calf base 12 .

[0039] Specifically, if Figure 3 、 Figure 4 As shown, in order to simulate the pronation and supination movements of the ulna and radius of the human body, the present invention cleverly designs the calf base 12 to be equivalent to the function of the ulna in the bionic mechanism, and the linear drive 3 and the first and second rotational joints 80 and 81 act as the radius and its pronator and supinator muscles to connect with the calf link 2 and the wrist joint 9, so that the wrist joint 9 can be driven to rotate by relying on the extension and contraction of the linear drive 3 to control the rotation angle of the wheel 41.

[0040] To this end, in this example, the first rotating joint 80 includes: a first joint 5 and a second joint 6, wherein the first joint 5 is Z-shaped, with a first longitudinal axis fork provided on its first side and the second side fixed on the bracket 21, and the second joint 6 is U-shaped fork-shaped, with a longitudinal axis hole provided on its concave side and a transverse axis hole provided near the fork head. The second joint 6 is connected to the first longitudinal axis fork rotating shaft of the first joint 5 through the longitudinal axis hole, and the fork head of the second joint 6 is connected to the first end rotating shaft of the linear drive 3 through the transverse axis hole to establish a two-degree-of-freedom hinge between the linear drive 3 and the calf link 2.

[0041] On the other hand, the second rotating joint 81 includes: a third joint 7 and a fourth joint 8, wherein the third joint 7 is in a U-shaped fork shape, and a longitudinal axis hole is provided on its concave side, and a transverse axis hole is provided near the fork head. The second longitudinal axis fork and the third longitudinal axis fork are respectively provided at both ends of the fourth joint 8, and the second longitudinal axis fork and the third longitudinal axis fork are inclined. The fourth joint 8 is connected to the longitudinal axis hole of the third joint 7 via the second longitudinal axis fork, and the fourth joint 8 is connected to the rudder bar 91 via the third longitudinal axis fork. The third joint 7 is connected to the second end axis of the linear drive 3 via the transverse axis hole at the fork head to establish a three-degree-of-freedom hinge between the linear drive 3 and the rudder bar 91.

[0042] Thus, the 7 components, including the shank link 2, wrist joint 9, linear drive 3, first joint 5, second joint 6, third joint 7, and fourth joint 8, together constitute the core of the bionic wrist joint. , number of institutions , number of joints , the degrees of freedom of each joint , the degrees of freedom of the mechanism can be calculated:

[0043]

[0044]

[0045] The number of joints Including Figure 2 The A to G labels are shown, and the institutional data Including: the extension / contraction of the linear drive 3 is regarded as two mechanisms, the calf connecting rod 2, the calf base 12 and the first joint 5 are regarded as one mechanism, the second joint 6, the third joint 7, and the fourth joint 8 are regarded as three mechanisms respectively, and the wrist joint 9 is regarded as one mechanism.

[0046] Therefore, driven by the linear actuator 3 , the wrist joint 9 can rotate relative to the calf base 12 to simulate the left and right swing of the wrist joint, thereby driving the wheel 41 to rotate.

[0047] Furthermore, in order to detect the rotation angle of the wheel 41, the wrist joint 9 in this embodiment is provided with a first axial hole, and a keyway is provided in the first axial hole, and the calf base 12 is provided with a second axial hole, and the calf base 12 and the wrist joint 9 are connected by an anti-loosening shaft 14 inserted into the first and second axial holes, wherein the anti-loosening shaft 14 is provided with a flat key to match the keyway in the first axial hole of the wrist joint 9 to fix the axial position of the anti-loosening shaft 14, and the top cover of the second axial hole of the calf base 12 is provided with an angle sensor 15, wherein in this embodiment, it is preferably a Hall angle sensor, and its sensing area is toward the top of the anti-loosening shaft 14.

[0048] Therefore, when the linear drive 3 is extended and retracted, the first and second rotary joints 80 and 81 can imitate the effects of the pronator and supinator muscles of the radius to pull the rudder bar 91, drive the wrist joint 9 and the wheel 41 associated with it to rotate, and also drive the anti-loosening shaft 14 to rotate synchronously. At this time, since the calf base 12 is fixed on the calf connecting rod 2, the relative position of the angle sensor 15 is fixed, so that its rotation angle relative to the anti-loosening shaft 14 can be identified, thereby detecting the rotation angle of the wheel 41, thereby forming a closed-loop control.

[0049] It is worth mentioning that the design of the bionic wheel-foot leg structure of the present invention is conducive to constructing a control relationship between the sensing data and the telescopic distance of the linear drive 3 for the rotation angle of the wheel 41. Compared with the existing technology, due to the change in the mechanical transmission structure, the bionic structure of this scheme can greatly simplify the complexity of the wheel 41 rotation angle control algorithm, thereby forming a control advantage.

[0050] Furthermore, in order to improve the ability of the wrist joint 9 and the calf base 12 to withstand the axial force of the anti-loosening shaft 14, in a preferred example, a bearing groove is provided at either the first axial hole of the wrist joint 9 or the second axial hole of the calf base 12 to accommodate the thrust bearing 13. The wrist joint 9 and the calf base 12 pass through the thrust bearing 13 via the anti-loosening shaft 14 and are inserted into the first and second axial holes to form a rotating shaft connection.

[0051] On the other hand, see Figures 5 to 8 As shown, in order for the bionic wheel-foot leg structure to support walking and knee-flexed lying modes, it is necessary to imitate the functional morphology of the thigh and calf of a living being. For this purpose, the bionic wheel-foot leg structure of the present invention, wherein the thigh part also includes: a joint motor group 1, a crank four-bar linkage 20, wherein the key motor group mainly realizes the imitation of the hip joint structure similar to that of the human body, and the crank four-bar linkage 20 mainly realizes the imitation of the knee joint of a living being and the transmission of its power.

[0052] Specifically, if Figure 7 As shown, the crank four-bar linkage 20 includes: a thigh link 21, a thigh auxiliary link 22, a driving link 23, and a knee joint link 24. The first ends of the thigh link 21 and the thigh auxiliary link 22 are respectively connected to the end motor stator of the joint motor group 1, the driving link 23 is connected to the end motor rotor of the joint motor group 1, the first end of the knee joint link 24 is connected to the crank 25 shaft of the driving link 23, and the second ends of the thigh link 21, the thigh auxiliary link 22, and the knee joint link 24 are respectively connected to the shafts at the corresponding positions on both sides of the third end of the calf link 2.

[0053] The joint motor group 1 includes: a first hip joint motor 26, a second hip joint motor 27, a second hip mounting seat 28, a knee mounting seat 29, and a knee joint motor 30. The second hip mounting seat 28 is connected to the stator of the second hip joint motor 27 on the lateral side and to the rotor of the first hip joint motor 26 on the longitudinal side. The stator of the knee joint motor 30 is connected to the rotor of the second hip joint motor 27 via the knee mounting seat 29. The first ends of the thigh connecting rod 21 and the thigh auxiliary connecting rod 22 are respectively connected to the stator of the knee joint motor 30, and the driving connecting rod 23 is connected to the rotor of the knee joint motor 30.

[0054] Thus, the rotation of the rotor of the first hip joint motor 26 enables the bionic wheel-foot leg structure to swing left and right. The rotor of the second hip joint motor 27 drives the second hip mounting base 28 to achieve a 90-degree axis shift. Furthermore, because the rotor of the second hip joint motor 27 is connected to one side of the knee mounting base 29, and the other side of the knee mounting base 29 is connected to the stator of the knee joint motor 30, when the knee joint motor 30 is not rotating, the rotation of the second hip joint motor 27 can drive the entire lower leg portion to swing forward and backward.

[0055] Furthermore, because the stator of the knee motor 30 is connected to the thigh link 21 and the thigh auxiliary link 22, and the rotor of the knee motor 30 is linked to the knee link 24 via the drive link 23, it can drive the shank link 2 to achieve swinging of the shank portion. Thus, the drive link 23, knee link 24, thigh link 21, and shank link 2 together form a crank-connecting rod four-bar mechanism, which transmits power to the knee joint and supports the bionic wheeled foot leg structure to switch between upright walking and knee-flexed prone modes.

[0056] It is worth mentioning that the bionic structure of the thigh part adopts a stacked structure design, and all connecting rod components are flattened. Therefore, the overall mechanism occupies a small volume and is lightweight, with the function of stretching and folding. The stacked structure design makes the impact resistance performance of its outer side better.

[0057] On the other hand, since the above-mentioned bionic wheel-foot leg structure is transformed into the knee-flexed prone mode, when it uses the wheels 41 to travel on bumpy roads, the connection part between the third end of the calf link 2 and the thigh link 21, the thigh auxiliary link 22, and the knee joint link 24 is easily subjected to force and vibration, thereby affecting the life and reliability of the knee joint structure here.

[0058] For this reason Figure 7 As shown, the joint motor group 1 in this example also includes: a shock absorber, which includes: a mounting ring 31, a support member 32, and a spring 33, wherein the spring 33 is fixed to one side of the mounting ring 31 through the support member 32, and the mounting ring 31 is connected to the first end of the thigh link 21. When the joint motor group 1 drives the crank four-bar linkage 20 to perform a knee-flexing and prone movement to approximately the limit, the spring 33 and the calf link 2 are offset.

[0059] The shock absorber can thus serve as an insurance in the extreme position of the prone position with the knees bent, and can also be used as a shock absorber when using the wheeled driving mode.

[0060] Corresponding to the bionic wheel-foot leg structure in the above example, Figure 9 As shown, the present invention also provides a wheel-foot robot, which includes: a wheel-foot leg 51 composed of any of the above-mentioned bionic wheel-foot leg structures, and a frame 50, wherein the frame 50 is used to install the wheel-foot leg 51.

[0061] In a preferred example, there are four wheel-foot legs 51, including two front legs and two rear legs, wherein the front legs and the rear legs have the same structure and are arranged in a front elbow and rear knee style.

[0062] In summary, the bionic wheel-foot leg structure and wheel-foot robot provided by the present invention cleverly realize the bionic structure of the wrist joint through only six mechanical components (calf connecting rod 2, linear drive 3, calf base 12, wrist joint component 9, first and second rotation joint components 81), thereby simulating the internal rotation and external rotation of the ulna and radius of a living being to support the wheel-foot rotation angle range from -60 degrees to +60 degrees, thereby greatly improving the flexibility of the wheel-foot leg structure.

[0063] On the other hand, the design of this bionic wheel-foot leg structure makes it possible to use a linear drive 3 to simulate the effects of the pronator teres and supinator muscles. Compared with existing solutions that require complex control algorithms, this solution can directly control the extension and contraction of the linear drive 3 to achieve and establish a control relationship with the left and right rotation and swing of the wrist joint 9. The operation is more convenient and is conducive to achieving more precise motion control of the robot. Moreover, since this structure does not require the use of a motor, compared with the existing technology, it also improves the miniaturization and lightweight of the wheel-foot leg structure and further reduces the implementation cost.

[0064] In addition, when the bionic wheel-foot leg structure is applied to a multi-legged wheel-foot robot, the steering function of wheeled motion can be realized, which is beneficial to avoid the friction generated during differential driving and improve the service life and reliability of the wheel-foot part.

[0065] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made based on the contents of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can better understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0066] In addition, various implementations of the embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims

1. A bionic wheel-foot leg structure, comprising: A calf connecting rod, a linear drive, a foot end unit, a joint motor group, and a crank four-bar linkage, wherein the foot end unit includes: a wheel, a drive motor, a wrist joint, and a calf base, wherein the drive motor is fixed to a first side of the wrist joint, a transmission end of the drive motor is connected to the wheel, the calf base is connected to a rotating shaft of the wrist joint, a rudder rod extends outward from the second side of the wrist joint, wherein a bracket extends outward from the first end of the calf connecting rod, a first end of the linear drive is hinged to the calf connecting rod bracket via a first rotating joint, and a second end is hinged to the rudder rod via a second rotating joint, and the second end of the calf connecting rod is connected to the calf base; The first rotary joint comprises: a first joint and a second joint, wherein the first joint is Z-shaped, with a first longitudinal axis fork provided on its first side and a second side fixed to a bracket, and the second joint is U-shaped fork-shaped, with a longitudinal axis hole provided on its concave side and a transverse axis hole provided near the fork head, the second joint is connected to the first longitudinal axis fork rotating shaft of the first joint via the longitudinal axis hole, and the fork head of the second joint is connected to the first end rotating shaft of the linear drive via the transverse axis hole, so as to establish a hinge with two degrees of freedom between the linear drive and the calf connecting rod; The second rotational joint component includes: a third joint and a fourth joint, wherein the third joint is in a U-shaped fork shape, a longitudinal axis hole is provided on its concave side, and a transverse axis hole is provided near the fork head, and a second longitudinal axis fork and a third longitudinal axis fork are provided at both ends of the fourth joint respectively, and the second longitudinal axis fork and the third longitudinal axis fork are inclined, the fourth joint component is connected to the third joint longitudinal axis hole rotating shaft via the second longitudinal axis fork, the fourth joint component is connected to the rudder shaft via the third longitudinal axis fork, and the third joint is connected to the second end rotating shaft of the linear drive via the transverse axis hole at the fork head, so as to establish a three-degree-of-freedom hinge between the linear drive and the rudder shaft; The crank four-bar linkage includes: a thigh link, a thigh auxiliary link, a driving link, and a knee joint link. The first ends of the thigh link and the thigh auxiliary link are respectively connected to the end motor stator of the joint motor group, the driving link is connected to the end motor rotor of the joint motor group, the first end of the knee joint link is connected to the crank shaft of the driving link, and the second ends of the thigh link, the thigh auxiliary link, and the knee joint link are respectively connected to the shaft at the corresponding position of the third end of the calf link.

2. The bionic wheel-foot leg structure according to claim 1, wherein the wrist joint is provided with a first axial hole, and a keyway is provided in the first axial hole, and the calf base is provided with a second axial hole, and the calf base and the wrist joint are connected by an anti-loosening shaft inserted into the first and second axial holes to form a rotating shaft, wherein the anti-loosening shaft is provided with a flat key to match the keyway in the first axial hole of the wrist joint to fix the axial position of the anti-loosening shaft, and the top cover of the second axial hole of the calf base is provided with an angle sensor, and its sensing area faces the top of the anti-loosening shaft.

3. The bionic wheel-foot leg structure according to claim 2, wherein a bearing groove is provided at either the first axial hole of the wrist joint or the second axial hole of the calf base to accommodate a thrust bearing, and the wrist joint and the calf base are connected by a pivot shaft passing through the thrust bearing and inserted into the first and second axial holes.

4. The bionic wheel-foot leg structure according to claim 1, wherein the joint motor group comprises: A first hip joint motor, a second hip joint motor, a second hip mounting seat, a knee mounting seat, and a knee joint motor. The second hip mounting seat is connected to the stator of the second hip joint motor on the lateral side and to the rotor of the first hip joint motor on the longitudinal side. The stator of the knee joint motor is connected to the rotor of the second hip joint motor via the knee mounting seat. The first ends of the thigh connecting rod and the thigh auxiliary connecting rod are respectively connected to the stator of the knee joint motor. The driving connecting rod is connected to the rotor of the knee joint motor.

5. The bionic wheel-foot leg structure according to claim 4, wherein the joint motor group further comprises: The shock absorber includes: a mounting ring, a support member, and a spring, wherein the spring is fixed to one side of the mounting ring via the support member, the mounting ring is connected to the first end of the thigh connecting rod, and when the joint motor group drives the crank four-bar linkage to perform a knee-bending and prone movement to an approximate limit, the spring and the calf connecting rod are offset.

6. A wheel-legged robot comprising: A wheel-foot leg composed of the bionic wheel-foot leg structure according to any one of claims 1 to 5, and a frame, wherein the frame is used to install the wheel-foot leg.

7. The wheeled-leg robot according to claim 6, wherein the wheeled-leg legs are four, including two front legs and two hind legs, wherein the front legs and the hind legs have the same structure and are arranged in a front elbow and back knee style.

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