Robot leg structure and biped robot

Abstract

The utility model belongs to the related technical field of robots, and discloses a robot leg structure and a biped robot, a hip joint module in the leg structure comprises a side expansion driving module, a turnover driving module and a pitching driving module, one ends of the three modules are installed on a hip joint installation frame in a series connection mode, and the other ends of the three modules are installed on a hip joint installation frame. The other end of the connecting rod is connected with the thigh part; the knee joint module is located in the containing cavity of the thigh part, the knee joint module comprises a linear driving module, the fixed end of the linear driving module is rotationally connected with the upper portion of the thigh part, the movable end of the linear driving module is in transmission connection with the top of the shank part, and the linear driving module drives the shank part to do pitching motion through linear telescopic movement; the bottom of the shank part is hinged to the foot bottom part through a cross shaft structure, and the ankle joint module is arranged on the shank part and is in transmission connection with the foot bottom part so as to complete pitching and side stretching movement. The design of hybrid driving of the linear and rotary joint modules gives consideration to the requirements of high robustness and low energy consumption of the foot-type robot in a real scene.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the related technical field of robot, more particularly, it relates to a robot leg structure and biped robot. BACKGROUND

[0002] With the rapid development of foot robot reinforcement learning operation and control algorithm, biped robot obtains a lot of attention and long development because of high terrain passability and high adaptability with human life environment.

[0003] At present, the configuration of twelve degrees of freedom biped robot mainly has two kinds, one is to drive all twelve degrees of freedom by using rotary motor, the advantage of this configuration is that the high dynamic force position response advantage of rotary joint module is used to the greatest extent, the robustness of robot walking in unstructured ground environment is improved, the disadvantage is that in the actual application scene of biped robot, the proportion of low dynamic working condition is very large, and the energy consumption of rotary joint module is large when the robot is in low dynamic or quasi-stationary state due to the limitation of electrical characteristics of rotary joint module.

[0004] Another scheme adopts linear joint module to drive all twelve degrees of freedom, linear joint module usually adopts the form of brushless DC motor driving planetary roller screw to output linear motion and drive joint movement. Planetary roller screw brings high rigidity characteristics to joint module, has the advantages of large load and low energy consumption, but sacrifices part of the dynamic response ability of robot and reduces the robustness. CONTENT OF UTILITY MODEL

[0005] In view of the above defects or improvement needs of prior art, the utility model provides a robot leg structure and biped robot, which is used to solve the contradiction between high energy consumption of full rotary joint and poor robustness of full linear joint in the configuration scheme of existing biped robot.

[0006] In order to achieve the above purpose, according to one aspect of the utility model, a robot leg structure is provided, which is composed of a hip joint module, a thigh part, a knee joint module, a calf part, an ankle joint module and a foot bottom, wherein:

[0007] The hip joint module includes a lateral abduction drive module, a circumrotation drive module and a pitch drive module, the three modules are installed on the hip joint installation frame in series at one end, and are connected with the top of the thigh part at the other end, the three modules each contain a rotary motor combined to form a three degrees of freedom hip joint;

[0008] The bottom of the thigh part is rotationally connected with the top of the calf part, the thigh part has a receiving cavity, the knee joint module is located in the receiving cavity of the thigh part, the knee joint module comprises a linear drive module, the fixed end of the linear drive module is rotationally connected with the upper part of the thigh part, the moving end of the linear drive module is transmissionally connected with the top of the calf part, and the linear drive module drives the calf part to perform pitching movement through linear telescopic movement.

[0009] The bottom of the calf part is hingedly connected with the bottom of the foot through a cross shaft structure, the ankle joint module is arranged on the calf part, and the ankle joint module is transmissionally connected with the bottom of the foot to drive the bottom of the foot to perform pitching and lateral spreading movement.

[0010] According to the robot leg structure, the hip joint mounting frame comprises a front support, a rear support and a connecting plate, the front support and the rear support are connected with the connecting plate to form a receiving cavity, the lateral spreading drive module comprises a lateral spreading drive motor, the output end of the lateral spreading drive motor is connected with the rear support, the rotation drive module is located in the receiving cavity between the front support and the rear support, the rotation drive module comprises a rotation drive motor and a rotation drive motor base, the output end of the rotation drive motor is connected with the rotation drive motor base, one end of the rotation drive motor base is connected with the output shaft of the lateral spreading drive motor, and the other end of the rotation drive motor base is hingedly connected with the front support.

[0011] The pitching drive module comprises a pitching drive motor and a support assembly, the pitching drive motor is connected with the output shaft of the rotation drive motor through the support assembly, and the output shaft of the pitching drive motor is connected with the top of the thigh part.

[0012] According to the robot leg structure, the rotation drive module further comprises a rotation cross roller bearing, a bearing inner ring pressing flange and a bearing outer ring pressing flange, the rotation cross roller bearing is arranged in the opening of the rotation drive motor base, the output shaft of the rotation drive motor is connected with the bearing inner ring pressing flange, the bearing inner ring pressing flange is matched with the inner ring of the rotation cross roller bearing, the bearing outer ring pressing flange is connected with the rotation drive motor base, and the bearing outer ring pressing flange and the rotation drive motor base jointly press the outer ring of the rotation cross roller bearing.

[0013] According to the robot leg structure, the bracket assembly comprises a pitch motor bracket arranged on both sides of the pitch driving motor and an auxiliary bracket, the top of the pitch motor bracket and the auxiliary bracket is connected with the bearing inner ring pressing flange at the same time, the top of the pitch motor bracket is matched with the inner ring of the revolving cross roller bearing at the same time, the tail end of the pitch driving motor is connected with the pitch motor bracket, the auxiliary bracket is connected with the output end of the pitch driving motor, one end of the pitch motor bracket is connected with the pitch bearing seat, the other end of the pitch bearing seat is connected with the pitch cross roller bearing, one side of the top of the thigh part is connected with the output shaft of the pitch driving motor, and the other side is connected with the pitch cross roller bearing.

[0014] According to the robot leg structure, the thigh part comprises a thigh outer plate and a thigh inner plate which are oppositely arranged, the thigh outer plate and the thigh inner plate are connected through a plug bolt to form a containing cavity, the thigh outer plate and the thigh inner plate are connected through a first plug bolt at the upper part, and the fixed end of the linear driving module is rotatably connected to the first plug bolt.

[0015] According to the robot leg structure, the thigh outer plate and the thigh inner plate are further connected through a second plug bolt and a third plug bolt at the lower part, the linear driving module is in transmission connection with the upper knee connecting rod and the lower knee connecting rod and the calf part, the moving end of the linear driving module is rotatably connected to the first end of the upper knee connecting rod and the first end of the lower knee connecting rod, the second end of the upper knee connecting rod is rotatably connected to the second plug bolt, the second end of the lower knee connecting rod is rotatably connected to the top of the calf part, and the top of the calf part is rotatably connected to the thigh part through the third plug bolt.

[0016] According to the robot leg structure, the upper knee connecting rod and the lower knee connecting rod are both in Y shape, and the first end of the upper knee connecting rod and the first end of the lower knee connecting rod are respectively bifurcated ends.

[0017] According to the robot leg structure, the moving end of the linear driving module, the first end of the upper knee connecting rod and the first end of the lower knee connecting rod are respectively sleeved on the up-down connecting rod shaft, knee joint bearings are arranged between the first end of the upper knee connecting rod and the up-down connecting rod shaft and between the first end of the lower knee connecting rod and the up-down connecting rod shaft, and an up-down connecting rod shaft sleeve is arranged on the up-down connecting rod shaft at the side of the knee joint bearing.

[0018] According to the robot leg structure provided by the utility model, the ankle joint module contains two ankle joint driving motors which are installed on the lower leg part, a rocker is installed on the output shaft of each of the two ankle joint driving motors, the rocker located on the upper side is hinged to one end of a long connecting rod, the rocker located on the lower side is hinged to one end of a short connecting rod, and the other end of the long connecting rod and the other end of the short connecting rod are respectively hinged to the foot bottom and distributed on the two sides of the foot bottom.

[0019] According to another aspect of the utility model, a biped robot is provided, comprising the robot leg structure of any one of the above.

[0020] Overall, compared with the prior art, the robot leg structure and the biped robot provided by the utility model have the following advantages:

[0021] 1. The three degrees of freedom of the hip joint and the two degrees of freedom of the ankle are driven by the rotary joint module, which can ensure that the robot has basic high dynamic characteristics, the one degree of freedom of the knee joint is driven by the linear joint module, which can greatly reduce the energy consumption of the robot under low dynamic conditions and improve the load of the robot; the design of the mixed driving of the linear and rotary joint modules can meet the needs of high robustness and low energy consumption of the leg robot in real scenes;

[0022] 2. The specific connection structure of the three modules in the hip joint module is reasonably and compactly designed in space, and the structure is simple and convenient for assembly; the linear driving module in the knee joint module is connected with the lower leg part through the upper knee connecting rod and the lower knee connecting rod, which is beneficial to improve the stability of the transmission;

[0023] 3. The Y-shaped structure design of the upper knee connecting rod and the lower knee connecting rod can weaken the quick return characteristics of the connecting rod mechanism, that is, the torque and speed of the end output are more stable. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The biped robot structure schematic diagram shown in the utility model embodiment;

[0025] Figure 2 The hip joint module exploded view shown in the utility model embodiment;

[0026] Figure 3 The turn-to-drive module exploded view shown in the utility model embodiment;

[0027] Figure 4 The pitch drive module exploded view shown in the utility model embodiment;

[0028] Figure 5 The upper thigh part exploded view shown in the utility model embodiment;

[0029] Figure 6 A knee joint module exploded view shown in the embodiment of the utility model;

[0030] Figure 7 A ankle joint module exploded view shown in the embodiment of the utility model;

[0031] In all the drawings, the same reference signs are used to indicate the same elements or structures, wherein:

[0032] 1, hip joint module;11, hip joint installation frame;12, side spread drive module;13, week transfer drive module;14, pitch drive module;111, front support;112, rear support;113, connecting plate;131, week transfer drive motor;132, bearing inner ring compression flange;133, week transfer drive motor base;134, week transfer bearing;135, week transfer cross roller bearing;136, bearing outer ring compression flange;141, auxiliary support;142, pitch drive motor;143, pitch motor support;144, pitch bearing seat;145, pitch cross roller bearing;2, leg trunk;21, thigh;22, shank;211, thigh outer plate;212, thigh inner plate;213, first plug bolt;214, second plug bolt;215, third plug bolt;3, knee joint module;31, linear motor;32, knee upper connecting rod;33, knee lower connecting rod;34, upper and lower connecting rod shaft;35, inner side upper and lower connecting rod shaft sleeve;36, outer side upper and lower connecting rod shaft sleeve;37, lower connecting rod shank shaft;38, lower connecting rod shaft sleeve;39, knee joint bearing;4, ankle joint module;41, ankle joint drive motor;42, rocker;43, long connecting rod;44, short connecting rod;45, connecting rod shaft;46, fish eye bearing;47, ankle joint shaft sleeve;48, connecting rod cover plate;49, cross axle structure;50, ankle joint bearing;51, shaft end nut;52, foot plate. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following will be further described in detail with the help of the drawings and examples. It should be understood that the specific examples described here are only used to explain the utility model, and are not used to limit the utility model. In addition, the technical features involved in each embodiment of the utility model described below can be combined with each other as long as they do not conflict with each other.

[0034] Please refer to Figure 1 The embodiment provides a robot leg structure, which is composed of a hip joint module 1, a thigh 21, a knee joint module 3, a shank 22, an ankle joint module 4 and a foot bottom, wherein the thigh 21 and the shank 22 form a leg trunk 2, and the hip joint module 1 is connected to the thigh 21 through a hip joint installation frame 11.

[0035] The hip joint module 1 comprises a lateral abduction driving module 12, a circumduction driving module 13 and a pitch driving module 14, which are connected in series at one end to the hip joint mounting frame 11 and at the other end to the top of the thigh part 21, and each of the three modules comprises a rotary motor to form a three-degree-of-freedom hip joint.

[0036] The bottom of the thigh part 21 is rotatably connected to the top of the lower leg part 22, the thigh part 21 has a receiving cavity, the knee joint module 3 is located in the receiving cavity of the thigh part 21, the knee joint module 3 comprises a linear driving module, the fixed end of the linear driving module is rotatably connected to the upper part of the thigh part 21, and the moving end of the linear driving module is drivingly connected to the top of the lower leg part 22, so that the linear driving module drives the lower leg part 22 to pitch through linear extension and contraction.

[0037] The bottom of the lower leg part 22 is hingedly connected to the foot bottom through a cross shaft structure 49, the ankle joint module 4 is arranged on the lower leg part 22, and the ankle joint module 4 is drivingly connected to the foot bottom to drive the foot bottom to pitch and laterally abduct.

[0038] In some embodiments, with reference to Figure 2 and Figure 3 , the hip joint mounting frame 11 comprises a front support 111, a rear support 112 and a connecting plate 113, the front support 111 and the rear support 112 are respectively connected to the connecting plate 113 by bolts or the like to form a receiving cavity. The lateral abduction driving module 12 comprises a lateral abduction driving motor, which is a rotary motor. The output end of the lateral abduction driving motor is connected to the rear support 112 by bolts or the like.

[0039] The circumduction driving module 13 is located in the receiving cavity between the front support 111 and the rear support 112, the circumduction driving module 13 comprises a circumduction driving motor 131 and a circumduction driving motor base 133, the output end of the circumduction driving motor 131 is connected to the circumduction driving motor base 133 by screws, one end of the circumduction driving motor base 133 is connected to the output shaft of the lateral abduction driving motor, and the other end is hingedly connected to the front support 111. The output end of the motor, i.e. one end provided with an output shaft, is connected to the motor housing part.

[0040] One end of the circumduction driving motor base 133 is provided with a mounting boss, the mounting boss is connected to the output shaft of the lateral abduction driving motor by screws, the other end of the circumduction driving motor base 133 is provided with a connecting shaft, the front support 111 is provided with a mounting hole, the connecting shaft is inserted into the mounting hole and rotatably connected to the front support 111 by a circumduction bearing 134.

[0041] When assembling, the lateral abduction driving module 12 should be first installed on the rear support 112, then the per revolution driving motor base 133 is connected to the output shaft of the lateral abduction driving module 12 by screws and the rear support 112 is installed on the connecting plate 113, ensuring that the other end of the per revolution driving motor base 133 is located in the bearing hole of the front support 111. Then the per revolution bearing 134 is installed in the bearing hole of the front support 111, so that the outer ring of the per revolution bearing 134 is matched with the bearing hole and the inner ring is matched with the other end of the per revolution driving motor base 133. Finally, the retaining ring is installed to prevent the per revolution bearing 134 from falling off. At this point, the per revolution driving module 13 is hinged with the hip joint mounting frame 11 and the lateral abduction driving module 12 can drive the per revolution driving module 13 to move laterally.

[0042] Reference Figure 3 and Figure 4 The pitch driving module 14 includes a pitch driving motor 142 and a support assembly, the pitch driving motor 142 is connected with the output shaft of the per revolution driving motor 131 through the support assembly, and the output shaft of the pitch driving motor 142 is connected with the top of the thigh part 21.

[0043] The per revolution driving module 13 further includes a per revolution crossed roller bearing 135, a bearing inner ring pressing flange 132 and a bearing outer ring pressing flange 136; the per revolution crossed roller bearing 135 is arranged in the opening of the per revolution driving motor base 133, the output shaft of the per revolution driving motor 131 is connected with the bearing inner ring pressing flange 132 by screws or the like, the bearing inner ring pressing flange 132 is matched with the inner ring of the per revolution crossed roller bearing 135, the bearing outer ring pressing flange 136 is connected with the per revolution driving motor base 133, and the bearing outer ring pressing flange 136 and the per revolution driving motor base 133 jointly press the outer ring of the per revolution crossed roller bearing 135; the support assembly is connected to the bearing inner ring pressing flange 132.

[0044] Reference Figure 3 The middle of the per revolution driving motor base 133 is provided with a circular opening, and the circular opening is provided with a stepped opening on the downward side, the per revolution crossed roller bearing 135 is placed on the stepped surface of the stepped opening, and specifically the outer ring is placed on the stepped surface and the inner ring is located inside the circular opening. The bottom of the bearing inner ring pressing flange 132 is provided with a boss, which is inserted into the inner ring of the per revolution crossed roller bearing 135 and is in contact with the inner wall surface of the inner ring, and at the same time the bearing inner ring pressing flange 132 is pressed on the upper end surface of the inner ring. So that the bearing inner ring pressing flange 132 is matched with the inner ring of the per revolution crossed roller bearing 135 and abuts against the end surface of the inner ring of the per revolution crossed roller bearing 135.

[0045] The bearing outer ring pressing flange 136 is also provided with an opening, and a ring-shaped boss is arranged on the outer edge of the opening at the upper end face. When the bearing outer ring pressing flange 136 is connected to the rotating drive motor base 133 through a screw, the ring-shaped boss is pressed against the lower end face of the outer ring of the rotating cross roller bearing 135. The bearing outer ring pressing flange 136 and the rotating drive motor base 133 jointly press the outer ring of the rotating cross roller bearing 135. Specifically, the circular opening on the rotating drive motor base 133 is provided with two stepped faces on the downward side. The outer ring of the rotating cross roller bearing 135 is placed on the upper stepped face, and the ground surface of the outer ring is flush with the lower stepped face, so that the ring-shaped boss on the bearing outer ring pressing flange 136 is pressed against the outer ring and the lower stepped face at the same time. Then, the edge part of the bearing outer ring pressing flange 136 is connected to the rotating drive motor base 133.

[0046] When assembling the rotating drive module 13, the rotating drive motor 131 should be installed first, then the bearing inner ring pressing flange 132 is installed, and then the rotating cross roller bearing 135 is installed. After confirming that the inner ring, the outer ring, and the inner ring end face of the rotating cross roller bearing 135 are all matched in place, the bearing outer ring pressing flange 136 is installed. The pitching drive module 14 is connected to the rotating drive module 13 through the bearing inner ring pressing flange 132, so that the rotating drive module 13 can drive the pitching drive module 14 to rotate.

[0047] Reference Figure 4 The support assembly includes the pitching motor support 143 and the auxiliary support 141 arranged on both sides of the pitching drive motor 142. The top of the pitching motor support 143 and the auxiliary support 141 is connected to the bearing inner ring pressing flange 132 at the same time. The flange plate at the top of the auxiliary support 141 can be connected to the bearing inner ring pressing flange 132 below the flange plate at the top of the pitching motor support 143. The bolts for installing the auxiliary support 141 will pass through the through holes at the corresponding positions of the pitching motor support 143 and be connected to the bearing inner ring pressing flange 132.

[0048] The upper end of the flange plate at the top of the pitching motor support 143 can be provided with a boss, which can be inserted into the inner ring of the rotating cross roller bearing 135, and at the same time, the flange plate at the top of the pitching motor support 143 is pressed against the lower end face of the inner ring. The top of the pitching motor support 143 is matched with the inner ring of the rotating cross roller bearing 135 at the same time, and the bearing inner ring pressing flange 132 jointly presses the inner ring of the rotating cross roller bearing 135.

[0049] The tail end of the pitch driving motor 142 is connected with the pitch motor support 143, the auxiliary support 141 is connected with the output end of the pitch driving motor 142, one end of the pitch motor support 143 is connected with the pitch bearing seat 144 through screws, the other end of the pitch bearing seat 144 is connected with the pitch crossed roller bearing 145, for example, the outer ring of the pitch crossed roller bearing 145 is connected with the pitch crossed roller bearing 145 through screws, one side of the top of the thigh part 21 is connected with the output shaft of the pitch driving motor 142, and the other side is connected with the pitch crossed roller bearing 145, for example, the inner ring of the pitch crossed roller bearing 145 is connected with the pitch crossed roller bearing 145 through screws.

[0050] Reference Figure 5 The thigh part 21 includes the thigh outer plate 211 and the thigh inner plate 212 arranged oppositely, the thigh outer plate 211 and the thigh inner plate 212 are connected through the jack bolt to form a containing cavity, the thigh outer plate 211 and the thigh inner plate 212 are connected through the first jack bolt 213 at the upper part, and the fixed end of the linear driving module is rotatably connected to the first jack bolt 213.

[0051] The thigh inner plate 212 and the thigh outer plate 211 are provided with hollow structures, and the inner sides of the thigh inner plate 212 and the thigh outer plate 211 are respectively provided with mounting columns provided with through holes for passing through the jack bolt and limiting the components sleeved on the jack bolt.

[0052] Reference Figure 5 The thigh outer plate 211 and the thigh inner plate 212 are further connected through the second jack bolt 214 and the third jack bolt 215 at the lower part, the thigh outer plate 211 and the thigh inner plate 212 are connected through the first jack bolt 213, the second jack bolt 214 and the third jack bolt 215 to form a containing cavity, and the thigh outer plate 211 is connected with the inner ring of the pitch crossed roller bearing 145, so that the pitch driving module 14 can drive the thigh part 21 to complete the pitch action, the thigh inner plate 212 is connected with the output shaft of the pitch driving motor 142, and the thigh part 21 and the calf part 22 are hinged together through the third jack bolt 215 and the nut.

[0053] Reference Figure 5The knee module 3 further comprises an upper knee link 32 and a lower knee link 33. The linear drive module can be a linear motor 31. The linear drive module is in transmission connection with the lower leg 22 through the upper knee link 32 and the lower knee link 33. The moving end of the linear drive module is in rotational connection with the first end of the upper knee link 32 and the first end of the lower knee link 33. The second end of the upper knee link 32 is rotatably connected to the second set screw 214. The second end of the lower knee link 33 is rotatably connected to the top of the lower leg 22. The top of the lower leg 22 is further rotatably connected to the upper leg 21 through a third set screw 215.

[0054] Specifically, the upper knee link 32 and the lower knee link 33 are both Y-shaped, comprising a large end and a small end. The bifurcated end is the large end, and the non-bifurcated end is the small end. The first end of the upper knee link 32 and the first end of the lower knee link 33 are bifurcated ends.

[0055] With reference to Figure 6 The moving end of the linear drive module, the first end of the upper knee link 32, and the first end of the lower knee link 33 are respectively sleeved on the upper and lower link shaft 34. The first end of the upper knee link 32 and the first end of the lower knee link 33 are respectively provided with knee joint bearings 39 between them and the upper and lower link shaft 34. The upper and lower link shaft 34 is provided with an upper and lower link shaft sleeve on the side of the knee joint bearing 39.

[0056] Specifically, the large end and the small end of the upper knee link 32 and the lower knee link 33 are respectively provided with knee joint bearings 39. The knee joint bearings 39 have flanges, and the flange end is directed outward during installation. The fixed end of the linear motor 31 is hinged to the outer thigh plate 211 and the inner thigh plate 212 through a first set screw 213. The output end is coaxially rotatably connected to the large end of the upper knee link 32 and the large end of the lower knee link 33 through the upper and lower link shaft 34.

[0057] The upper and lower link shaft 34 is provided with a check ring at both ends to prevent the knee joint bearing 39 of the large end of the upper knee link 32 from falling off. The outer upper and lower link shaft sleeve 36 is installed between the knee joint bearings 39 of the upper knee link 32 and the lower knee link 33 and is axially positioned through the outer upper and lower link shaft sleeve 36. The inner upper and lower link shaft sleeve 35 is installed between the knee joint bearing 39 of the lower knee link 33 and the output end of the linear motor 31 and is axially positioned through the inner upper and lower link shaft sleeve 35. The holes on both sides of the small end of the upper knee link 32 are respectively provided with knee joint bearings 39 to cooperate with the second set screw 214 to realize the hinge connection of the upper knee link 32 and the upper leg 21.

[0058] The lower leg part 22 has two upper and two lower bearing mounting holes near one end of the thigh part 21 for mounting knee joint bearings 39, one end of which has a flange, facing the outside of the lower leg part 22, and the upper two knee joint bearings 39 are used to cooperate with the third set of bolts 215 to realize the articulation of the lower leg part 22 and the thigh part 21. The lower two knee joint bearings 39 are articulated with the knee joint bearings 39 on the small end of the lower knee joint connecting rod 33 through the lower connecting rod lower leg shaft 37, and the two bearings are axially positioned by the lower connecting rod shaft sleeve 38. The lower connecting rod lower leg shaft 37 is provided with a check ring at both ends to prevent the bearings from falling off. Thus, the movement of the output end of the linear cylinder will be transmitted to the lower leg part 22 through the upper knee joint connecting rod 32 and the lower knee joint connecting rod 33, driving the knee joint to bend. This knee joint mechanism can attenuate the quick return characteristics of the connecting rod mechanism, that is, the torque and speed of the end output are more stable.

[0059] Reference Figure 7 The ankle joint module 4 includes two ankle joint drive motors 41 mounted on the lower leg part 22, and a rocker 42 is mounted on the output shaft of each of the two ankle joint drive motors 41. The upper rocker 42 is articulated with one end of a long connecting rod 43, and the lower rocker 42 is articulated with one end of a short connecting rod 44. The other ends of the long connecting rod 43 and the short connecting rod 44 are respectively articulated with the foot bottom and distributed on both sides of the foot bottom.

[0060] The lower leg part 22 includes a lower leg frame, and the lower leg frame is provided with two annular mounting frames for mounting the two ankle joint drive motors 41. The foot bottom includes a foot bottom plate 52.

[0061] Specifically, the two ankle joint drive motors 41 are connected to the lower leg part 22 through the tail end, one inside and one outside, one above and one below, wherein the ankle joint drive motor 41 with the output shaft facing the inside of the body is mounted above the lower leg part 22, and the ankle joint drive motor 41 with the output shaft facing the outside of the body is mounted below the lower leg part 22. A rocker 42 is mounted on the output shaft of each of the two ankle joint drive motors 41. The rocker 42 on the inside of the body is articulated with one end of a long connecting rod 43, and the rocker 42 on the outside of the body is articulated with one end of a short connecting rod 44. The other end of the long connecting rod 43 is articulated with the inside of the foot bottom plate 52, and the other end of the short connecting rod 44 is articulated with the outside of the foot bottom plate 52. The long connecting rod 43 and the short connecting rod 44 are identical in structure except for the length, and the structures of the two ends of the connecting rod are also identical. The structure details will be described below taking the long connecting rod 43 as an example.

[0062] In assembly, the fish-eye bearing 46 is first placed in the bearing hole reserved at the two ends of the long connecting rod 43, the fish-eye bearing 46 is fixed through the connecting rod cover plate 48, then the connecting rod shaft 45 is passed through the shaft hole of the rocker 42 and the inner ring of the fish-eye bearing 46, thereby realizing the hinging of the long connecting rod 43 and the rocker 42. The connecting rod shaft 45 has a stop ring at both ends to prevent it from sliding out of the hinged parts. The inner ring of the fish-eye bearing 46 is axially positioned through the ankle joint shaft sleeve 47, and the ankle joint shaft sleeve 47 is sleeved on the connecting rod shaft 45. The two ends of the long connecting rod 43 and the short connecting rod 44 are hinged to the rocker 42 and the foot plate 52 through the above method. The rotation of the ankle joint driving motor 41 is transmitted to the foot plate 52 through the rocker 42, the long connecting rod 43 and the short connecting rod 44, thereby driving the foot plate 52 to complete the pitching and lateral spreading movement.

[0063] Further, the cross shaft structure 49 comprises two first shaft holes arranged along the same axial direction, and two second shaft holes arranged along another same axial direction, the axial directions of the first shaft holes and the second shaft holes can be perpendicular. The upper end of the lower leg part 22 is hinged to the upper leg part 21, the lower end is hinged to the two coaxial shaft holes of the cross shaft structure 49, for example, the first shaft holes, and the other two coaxial shaft holes of the cross shaft structure 49, for example, the second shaft holes are hinged to the foot plate 52.

[0064] The hinging mode can be, for example, that the end face of the shaft hole of the cross shaft is matched with the inner side end face of the inner ring of the ankle joint bearing 50, the outer ring of the ankle joint bearing 50 is matched with the stepped counterbore hole of the lower end of the lower leg part 22, and the stepped counterbore hole can realize the axial positioning of the lower leg part 22. The four shaft holes of the cross shaft are threaded holes, the head of the shaft end nut 51 is matched with the outer side end face of the inner ring of the ankle joint bearing 50 by rotating the shaft end nut 51 into the threaded hole, thereby realizing the axial fixation of the ankle joint bearing 50. The foot plate 52 can be connected with the other two shaft holes of the cross shaft through the same hinging mode. At this time, the foot plate 52 can be connected with the lower leg part 22 through the cross shaft structure 49 to realize the movement in two directions of pitching and lateral spreading. The hinging mode between the cross shaft structure 49 and the lower leg part 22 and the foot plate 52 can also be other modes, which aims to realize the rotation of the foot plate 52 relative to the lower leg part 22 in two degrees of freedom directions, and the specific description is not repeated.

[0065] Further, the embodiment also provides a biped robot, which comprises the robot leg structure of any one of the above, and specifically comprises two legs which are chiral symmetrical to each other.

[0066] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A robot leg structure characterized by comprising: The hip joint module, the thigh part, the knee joint module, the lower leg part, the ankle joint module and the foot bottom part are connected together, wherein: The hip joint module includes a side spread driving module, a rotation driving module and a pitch driving module, the three modules are installed on the hip joint installation frame in series, and the other end is connected with the top of the thigh part, the three modules each include a rotating motor, and the three modules are combined to form a three-degree-of-freedom hip joint; The bottom of the thigh part is rotationally connected with the top of the lower leg part, the thigh part has a receiving cavity, the knee joint module is located in the receiving cavity of the thigh part, the knee joint module includes a linear driving module, the fixed end of the linear driving module is rotationally connected with the upper part of the thigh part, the moving end of the linear driving module is transmissionally connected with the top of the lower leg part, and the linear driving module drives the lower leg part to perform pitch movement through linear extension and contraction movement; The bottom of the lower leg part is hingedly connected with the foot bottom part through a cross shaft structure, the ankle joint module is arranged on the lower leg part, and the ankle joint module is transmissionally connected with the foot bottom part to drive the foot bottom part to perform pitch and side spread movement.

2. The robotic leg structure of claim 1, wherein, The hip joint installation frame includes a front support, a rear support and a connecting plate, the front support and the rear support are connected with the connecting plate to form a receiving cavity, the side spread driving module includes a side spread driving motor, the output end of the side spread driving motor is connected with the rear support, the rotation driving module is located in the receiving cavity between the front support and the rear support, the rotation driving module includes a rotation driving motor and a rotation driving motor base, the output end of the rotation driving motor is connected with the rotation driving motor base, one end of the rotation driving motor base is connected with the output shaft of the side spread driving motor, and the other end of the rotation driving motor base is hingedly connected with the front support; The pitch driving module includes a pitch driving motor and a support assembly, the pitch driving motor is connected with the output shaft of the rotation driving motor through the support assembly, and the output shaft of the pitch driving motor is connected with the top of the thigh part.

3. The robotic leg structure of claim 2, wherein, The rotation driving module further includes a rotation cross roller bearing, a bearing inner ring pressing flange and a bearing outer ring pressing flange, the rotation cross roller bearing is arranged in the opening of the rotation driving motor base, the output shaft of the rotation driving motor is connected with the bearing inner ring pressing flange, the bearing inner ring pressing flange is matched with the inner ring of the rotation cross roller bearing, the bearing outer ring pressing flange is connected with the rotation driving motor base, and the bearing outer ring pressing flange and the rotation driving motor base jointly press the outer ring of the rotation cross roller bearing, and the support assembly is connected with the bearing inner ring pressing flange.

4. The robotic leg structure of claim 3, wherein, The support assembly comprises a pitch motor support and an auxiliary support arranged on both sides of the pitch driving motor, the top of the pitch motor support and the auxiliary support is connected with the bearing inner ring pressing flange, the top of the pitch motor support is matched with the inner ring of the revolving crossed roller bearing, the tail end of the pitch driving motor is connected with the pitch motor support, the output end of the pitch driving motor is connected with the auxiliary support, one end of the pitch motor support is connected with the pitch bearing seat, the other end of the pitch bearing seat is connected with the pitch crossed roller bearing, one side of the top of the thigh is connected with the output shaft of the pitch driving motor, and the other side is connected with the pitch crossed roller bearing.

5. The robotic leg structure of any of claims 1-4, wherein, The thigh comprises a thigh outer plate and a thigh inner plate arranged oppositely, the thigh outer plate and the thigh inner plate are connected by a plug bolt to form a containing cavity, the thigh outer plate and the thigh inner plate are connected by a first plug bolt at the upper part, and the fixed end of the linear driving module is rotatably connected to the first plug bolt.

6. The robotic leg structure of claim 5, wherein, The thigh outer plate and the thigh inner plate are further connected by a second plug bolt and a third plug bolt at the lower part, the linear driving module is drivingly connected with the upper knee connecting rod and the lower knee connecting rod and the shank, the moving end of the linear driving module is rotatably connected with the first end of the upper knee connecting rod and the first end of the lower knee connecting rod, the second end of the upper knee connecting rod is rotatably connected to the second plug bolt, the second end of the lower knee connecting rod is rotatably connected to the top of the shank, and the top of the shank is rotatably connected to the thigh through the third plug bolt.

7. The robotic leg structure of claim 6, wherein, The upper knee connecting rod and the lower knee connecting rod are both Y-shaped, and the first end of the upper knee connecting rod and the first end of the lower knee connecting rod are respectively bifurcated ends.

8. The robotic leg structure of claim 6, wherein, The moving end of the linear driving module, the first end of the upper knee connecting rod and the first end of the lower knee connecting rod are respectively sleeved on the up-down connecting rod shaft, knee joint bearings are arranged between the first end of the upper knee connecting rod and the up-down connecting rod shaft and between the first end of the lower knee connecting rod and the up-down connecting rod shaft, and an up-down connecting rod sleeve is arranged on the up-down connecting rod shaft at a position on the side of the knee joint bearings.

9. The robotic leg structure of any one of claims 1-4, wherein, The ankle module comprises two ankle driving motors installed on the shank, a rocker is arranged on the output shaft of each ankle driving motor, the upper rocker is hingedly connected to one end of a long connecting rod, the lower rocker is hingedly connected to one end of a short connecting rod, and the other end of the long connecting rod and the short connecting rod are respectively hingedly connected to the foot and distributed on both sides of the foot.

10. A biped robot characterized by comprising: The robot leg structure comprises the robot leg structure according to any one of claims 1-9.

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