A humanoid foot mechanism for a humanoid robot

Abstract

The application discloses a kind of anthropomorphic foot mechanical foot for humanoid robot, including the foot frame of connecting humanoid robot shank and other foot components, split foot arch, with the elastic buffer assembly of forming three-link, heel, with the elastic buffer assembly of forming three-link, two degrees of freedom toes with automatic reset function, ground contact detection sensor.The application makes the toes with pitch degree of freedom, makes the robot forefoot sole relative foot overall rotation, so as to realize anthropomorphic gait;By designing the toes with roll degree of freedom, foot arch elastic buffer assembly, heel elastic buffer assembly, the ability of robot foot to adapt to different terrain is enhanced;By designing contact sensor in foot, the ability of robot foot-ground perception is increased, so as to have the ability to realize static gait.The application can make robot realize more energy-saving, less noise, more anthropomorphic straight knee, toe gait;With the ability of buffering foot impact, adapt to unstructured ground.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of robotics and mechanical technology, and relates to a humanoid foot mechanical foot for a humanoid robot, in particular to a humanoid robot foot device supporting a humanoid gait and enhancing ground adaptability. BACKGROUND

[0002] In recent years, the field of humanoid robots has developed rapidly. Compared with wheeled robots, multi-rotor robots and other foot-type robots, humanoid robots can more easily integrate into human society and replace humans to complete operations and transportation.

[0003] Most of the current humanoid robots adopt flat feet and do not have foot-ground contact sensors. At the same time, due to the assumption in the control algorithm that the foot-ground contact is point contact, the foot posture is unchanged, and the body height is unchanged, the current humanoid robot walking gait mostly presents the characteristics of knee flexion, continuous stepping, and the foot bottom always maintaining horizontal to the ground. Although this reduces the difficulty of control and mechanical design and reduces manufacturing costs, knee flexion causes the robot knee joint motor to always be in a state of bearing high load, and continuous stepping also greatly increases the energy consumption of the robot. At the same time, this unnatural gait is not friendly enough when interacting with humans, and it is noisy and may mis-touch or mis-injure humans.

[0004] Based on the above reasons, it is necessary to design a bionic foot device that supports straight knees, toe gait, is highly adaptable, and has foot-ground sensors, which is the demand for the development of humanoid robots. SUMMARY

[0005] To solve the problems of the prior art, the present application provides a humanoid foot mechanical foot for a humanoid robot, which supports the humanoid robot to realize a humanoid straight knee and toe gait and adapt to unstructured ground.

[0006] The humanoid foot mechanical foot for a humanoid robot of the present application comprises a foot frame, a heel elastic buffer assembly, a heel assembly, an arch elastic buffer assembly, an arch assembly, and a toe assembly.

[0007] The front part and the rear part of the foot frame are respectively provided with the arch assembly and the heel assembly; meanwhile, the middle part and the rear end of the foot frame are respectively provided with a bearing hole and a through hole for connecting the robot calf and the ankle joint driving assembly.

[0008] The arch assembly is provided in two sets and arranged on the left and right sides of the foot frame 1. The middle parts of the two sets of arch assemblies are connected to the foot frame to form a rotating pair; the top parts of the arch assemblies are connected to the foot frame through the arch elastic buffer assembly, and the bottom parts of the arch assemblies are used to connect the toe assembly.

[0009] The toe assembly comprises a toe body and a cross shaft, wherein the bottom surface of the toe body is a plane, and the front and rear opposite connecting shafts of the cross shaft are connected with the support seats fixedly installed on the toe body at the front and rear positions to form a rotating pair.

[0010] The two toe assemblies of the above structure are connected with the bottom of the arch assembly through the left and right opposite connecting shafts of the cross shaft to form a rotating pair.

[0011] The two roll degree torsional springs are sleeved on the front and rear rotating shafts of the cross shaft, and the rotation directions of the two roll degree torsional springs are opposite.

[0012] The pitch degree torsional spring is sleeved on the left and right rotating shafts of the cross shaft.

[0013] The bottom of the heel assembly is a plane, and the top is provided with joints in the front and rear directions.

[0014] The bottom surfaces of the toe body and the heel assembly are both paved with toe rubber pads.

[0015] The advantages of the present application are as follows:

[0016] 1. The present application is a humanoid foot mechanical foot for a humanoid robot, which is simple in structure and reasonable in design.

[0017] 2、The application is used for the humanoid foot mechanical foot of humanoid robot, adopts passive design, no driver in the device, effectively reduces the power consumption in the working process of the robot, at the same time uses aluminum alloy and other materials, so that the application is lighter in quality on the basis of meeting the operation demand, effectively enhances the endurance and maneuverability of the humanoid robot.

[0018] 3、The application is used for the humanoid foot mechanical foot of humanoid robot, through the design of the passive freedom degree of pitch direction of the toes, the robot carrying the device can realize straight knee and toe gait. When the foot and the ground exist an angle in the pitch direction, the forefoot formed by the two passive toes can still be attached to the ground, ensuring the surface contact between the foot and the ground; the passive torsion spring at the toe joint ensures that the forefoot can reset without external force, and makes the attachment effect of the forefoot and the ground better.

[0019] 4、The application is used for the humanoid foot mechanical foot of humanoid robot, through the design of the toes with two passive freedom degrees of roll and pitch directions, two-section arches, arch elastic buffer components and heel elastic buffer components, the influence of the impact and vibration between the foot and the ground on the robot body is weakened, the flexible movable forefoot and heel also improve the ability of the foot device to adapt to unstructured ground, and improve the ability of the humanoid robot to adapt to different scenes.

[0020] 5、The application is used for the humanoid foot mechanical foot of humanoid robot, through the way of increasing the ground touch sensor on the bottom surface of the foot device, the foot-ground perception ability of the robot is increased, so that the switching strategy of the support leg and the swing leg of the robot can be changed from fixed time trigger to ground touch event, so that the robot does not need to keep stable through continuous step gait.

[0021] 6、The application is used for the humanoid foot mechanical foot of humanoid robot, completely adopts passive design, avoids introducing motor, reducer and other driving modules, thereby reducing the weight, and reducing the dimension of control problem. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the overall structure diagram of the humanoid foot mechanical foot of the application;

[0023] Figure 2 It is the foot frame structure diagram in the humanoid foot mechanical foot of the application;

[0024] Figure 3 It is the arch assembly structure schematic diagram in the humanoid foot mechanical foot of the application;

[0025] Figure 4 It is the toe assembly structure schematic diagram in the humanoid foot mechanical foot of the application;

[0026] Figure 5Structure sectional view of the toe assembly in the artificial foot mechanical foot of the present application

[0027] Figure 6 Structure diagram of the heel elastic buffer assembly in the artificial foot mechanical foot of the present application

[0028] Figure 7 Sectional view of the heel elastic buffer assembly in the artificial foot mechanical foot of the present application

[0029] Figure 8 Structure diagram of the heel assembly in the artificial foot mechanical foot of the present application

[0030] Figure 9 Sectional view of the heel assembly in the artificial foot mechanical foot of the present application

[0031] Figure 10 Structure diagram of the arch elastic buffer assembly in the artificial foot mechanical foot of the present application

[0032] Figure 11 Sectional view of the arch elastic buffer assembly in the artificial foot mechanical foot of the present application

[0033] Figure 12 Schematic diagram of the forefoot landing process in the artificial foot mechanical foot of the present application

[0034] Figure 13 Schematic diagram of the foot rotation along the roll direction relative to the ground in the artificial foot mechanical foot of the present application

[0035] Figure 14 Schematic diagram of the heel landing process in the artificial foot mechanical foot of the present application

[0036] In the figure:

[0037] 1 - foot frame 2 - heel elastic buffer assembly 3 - heel assembly

[0038] 4 - arch elastic buffer assembly 5 - arch assembly 6 - two-degree-of-freedom toe assembly

[0039] 101 - bearing hole 102 - first light hole 103 - second light hole

[0040] 104 - third light hole 105 - fourth light hole bearing hole 101

[0041] 106 - fifth light hole 201 - guide rod limiting connecting piece 202 - compression spring

[0042] 203 - sliding shaft sleeve 204 - spring limiting sleeve 205 - sliding guide rod

[0043] 206 - limiting plate 301 - heel main body 302 - heel rubber pad

[0044] 301a-frame connecting head 301b-buffer assembly hinged seat 401-limiting nut

[0045] 402-buffer assembly connecting shaft 403-spring limiting sleeve 404-compression spring

[0046] 405-guide rod 406-buffer assembly sliding shaft sleeve 501-lateral arch frame 502-medial arch frame 503-toe pitch freedom torsion spring 504-pitch freedom torsion spring spring protection shell

[0047] 601-cross shaft 602-toe sliding shaft sleeve 603-toe roll freedom torsion spring

[0048] spring protection shell

[0049] 604-toe body 605-toe rubber pad DETAILED DESCRIPTION

[0050] The application will be further described in detail below with reference to the accompanying drawings.

[0051] The application is a humanoid robot's anthropomorphic foot mechanical foot, including foot frame 1, heel elastic buffer assembly 2, heel assembly 3, arch elastic buffer assembly 4, arch assembly 5, two-degree-of-freedom toe assembly 6, as shown in Figure 1 .

[0052] As shown in Figure 2 , the foot frame 1 is used to connect the humanoid robot's lower leg and other foot parts, and the middle part has bearing holes 101 opened in the left-right direction for connecting the humanoid robot's lower leg. The outer periphery of the lower side of the bearing hole 101 is provided with five light holes from front to back, respectively, the first light hole 102 in front of the bearing hole 101, the second light hole 103, the third light hole 104 below the bearing hole 101, the fourth light hole 105 and the fifth light hole 106 behind the bearing hole 101. Among them, the first light hole 102 is used to connect the arch assembly 5; the second light hole 103 is used to connect the arch elastic buffer assembly 4; the third light hole 104 is used to connect the heel assembly 3; the fourth light hole 105 is used to connect the heel elastic buffer assembly 2; the fifth light hole 106 is used to connect the ankle joint driving connecting rod.

[0053] As shown in Figure 3 , the arch assembly 5 is two sets, the same structure, composed of lateral arch frame 501 and medial arch frame 502.

[0054] The lateral arch outer frame 501 and the lateral arch inner frame 502 are symmetrically arranged left and right, and are both strip-shaped plate structures; a rectangular protrusion is designed in the middle of the lateral arch outer frame 501, the end face of the rectangular protrusion is attached to the inner wall of the middle of the lateral arch inner frame, and is fixed by a screw; thus, two U-shaped grooves are formed at the upper and lower ends of the lateral arch assembly 5, which are respectively used for connecting the lateral arch elastic buffer assembly 4 and the two-degree-of-freedom toe assembly 6.

[0055] The two sets of lateral arch assemblies 5 of the above structure are symmetrically arranged on the left and right sides of the foot frame 1; the bolt passes through the shaft hole and the first light hole 102 coaxially arranged in the middle of the two sets of lateral arch assemblies 5 in the transverse (left and right) direction, and is connected to the two sets of lateral arch assemblies 5 through a thrust bearing and a shaft sleeve, and is axially positioned by tightening the nut, so that the two sets of lateral arch assemblies 5 and the foot frame 1 form a rotating pair.

[0056] As shown in Figure 4 , Figure 5 The two-degree-of-freedom toe assembly 6 includes a cross shaft 601, a toe sliding shaft sleeve 602, a toe body 604, and a toe rubber pad 605.

[0057] The toe body 604 is a rectangular plate with a smooth transition at the circumferential corners. The middle of the cross shaft 601 has a cubic structure main body part, and the opposite pair of connecting shafts are arranged in the front and back directions and are connected to the shaft holes in the front and back support seats fixedly installed on the upper surface of the toe body 604 through the toe sliding shaft sleeve 602 to form a rotating pair. The lower surface of the toe body 604 is paved with the toe rubber pad 605 to increase the friction between the toe body 604 and the contact surface. At the same time, a sheet-shaped pressure sensor is installed between the toe body 604 and the toe rubber pad 605 to obtain the contact force between the toe body 604 and the contact surface in real time.

[0058] In the two sets of toe assemblies 6 of the above structure, the main body part of the cross shaft 601 is located in the U-shaped groove at the bottom end of the two sets of lateral arch assemblies 5; the opposite pair of left and right direction connecting shafts of the cross shaft 601 are connected to the shaft holes at the bottom end of the lateral arch outer frame 501 and the lateral arch inner frame 502 through the toe sliding shaft sleeve 602 to form a rotating pair. Thus, the cross shaft 601 provides the toe assembly 6 with roll (roll) and pitch (pitch) degrees of freedom.

[0059] The roll freedom motion reset of the two sets of toe assemblies 6 is achieved by two roll freedom torsion springs 606. The two roll freedom torsion springs 606 are sleeved on the front shaft of the cross shaft 601, and are located in the toe roll freedom torsion spring protection shell 603 installed on the upper surface of the toe body 604, and are separated by a partition plate. One end of the two roll freedom torsion springs 606 is located in the one-shaped groove at the end of the connecting shaft, and the other end is in contact with the inner wall of the toe roll freedom torsion spring protection shell 603 under the action of the pre-tightening force. The two roll freedom torsion springs rotate in opposite directions and can provide torque in opposite directions on the same axis. Under the action of the two roll freedom torsion springs 606, the bottom surface of the toe body 604 can be kept horizontal, and torque can be provided for the roll freedom rotation reset of the toe assembly 6.

[0060] The pitch freedom of the two sets of toe assemblies 6 is achieved by a pitch freedom torsion spring. The pitch freedom torsion spring is sleeved on the connecting shaft connected to the U-shaped groove and the medial arch inner frame 502, and is located in the toe pitch freedom torsion spring protection shell 503 fixedly installed on the bottom end outer wall of the medial arch inner frame 502. One end of the pitch freedom torsion spring 504 is located in the one-shaped groove at the end of the connecting shaft, and the other end is in contact with the inner wall of the toe pitch freedom torsion spring protection shell 503 under the action of the pre-tightening force. Under the action of the pitch freedom torsion spring 504, the toe assembly 6 can be kept in the forward limit rotation position of the pitch freedom, and torque can be provided for the pitch freedom rotation reset of the toe assembly 6.

[0061] The top end of the two sets of arch assemblies 5 is connected to the foot frame 1 by a set of arch elastic buffer assemblies 4. As shown in FIG. 4, the two sets of arch elastic buffer assemblies 4 are respectively connected to the top end of the two sets of arch assemblies 5, and the two sets of arch elastic buffer assemblies 4 are respectively connected to the foot frame 1. Figure 6 、 Figure 7As shown, the arch elastic buffer assembly 4 includes a limiting nut 401, a buffer assembly connecting shaft 402, an upper and lower spring limiting sleeve 403, a compression spring 404, a guide rod 405 and a buffer assembly sliding sleeve 406. The guide rod 405 is sequentially sleeved from top to bottom with two limiting nuts 401, a buffer assembly connecting shaft 402, an upper spring limiting sleeve 403, a compression spring 404 and a lower spring limiting sleeve 403. The lower end of the guide rod 405 is designed with a joint, the joint is provided with a connecting hole perpendicular to the axial direction of the guide rod 405, and the buffer assembly sliding sleeve 406 is installed in the connecting hole. The lower spring limiting sleeve 403 is in contact with the lower end limiting surface of the guide rod 405 for positioning. The compression spring 404 is sleeved between the upper and lower spring limiting sleeves 403, and the two ends are respectively positioned with the annular shoulder designed on the circumference of the two spring limiting sleeves 403. The buffer assembly connecting shaft 402 is sleeved on the guide rod 405 through the buffer assembly sliding sleeve 406, and the outer wall has two connecting ends perpendicular to the guide rod 405. The axial positioning between the components on the guide rod 405 is realized by tightening the double limiting nuts 401, and the compression spring 404 is adjusted in elasticity.

[0062] The two sets of arch elastic buffer assemblies 4 are arranged on the left and right sides of the foot frame 1, and the upper buffer assembly connecting shafts 402 are respectively located in the U-shaped grooves at the top ends of the two sets of arch assemblies 1. The two connecting ends of the connecting shafts are respectively connected to the shaft holes at the top ends of the arch outer frame 501 and the arch inner frame 502 through the buffer assembly sliding sleeve 406 to form a rotating pair. The joints at the lower ends of the two sets of arch elastic buffer assemblies 4 are respectively sleeved on the two ends of the rotating shaft inserted into the second light hole 103 of the foot frame 1 through the buffer assembly sliding sleeve 406 to form a rotating pair. When the toe assembly 6 is subjected to normal pressure from the ground, the two sets of arch elastic buffer assemblies 4 will be compressed. The compression spring 404 absorbs the energy of impact and vibration to realize shock absorption and reduce the influence of the foot bottom reaction force fluctuation on the overall machine body.

[0063] As shown in Figure 8 , Figure 9 The heel assembly 3 includes a heel body 301 and a heel rubber pad 302. The heel body 301 is a rectangular plate structure, and the top surface of the heel body 301 is designed with a frame connecting head 301a and a buffer assembly hinged seat 301b at the front and rear positions. The bottom surface of the heel body 301 is paved with a heel rubber pad 302, and the heel rubber pad 302 wraps the circumferential wall surface of the heel body 301. A sheet-shaped pressure sensor is also installed between the heel rubber pad 302 and the heel body 301 to realize the contact force between the heel assembly 3 and the contact surface.

[0064] The frame connecting head 301a is connected with the fourth light hole 105 in the foot frame 1 through a rotating shaft to form a rotating pair. The frame connecting head 301a is composed of two side strip plates, the bottom ends of which are connected with the top surface of the heel body 301, and the top ends of which are provided with through holes. The third light hole 104 in the foot frame 1 is disposed between the top ends of the two strip plates, and the rotating shaft passes through the through holes in the top ends of the two strip plates and the third light hole 104, and the two ends are connected with the two strip plates through shaft sleeves to form a rotating pair.

[0065] The above-mentioned buffer assembly connecting head 301b is connected with the foot frame 1 through two heel elastic buffer assemblies 2. As shown in Figure 10 、 Figure 11 The two heel elastic buffer assemblies 2 are the same in structure and include a guide rod limiting connecting piece 201, a compression spring 202, a sliding shaft sleeve 203, a spring limiting sleeve 204 and a sliding guide rod 205. The bottom end of the sliding guide rod 205 is designed with a joint, and the joint is provided with a connecting hole with an axis perpendicular to the sliding guide rod 205. The top end of the sliding guide rod 205 is inserted into the cylindrical guide rod limiting connecting piece 201 through a shaft sleeve. The sliding guide rod 205 is sleeved with the compression spring 202, and the upper and lower parts of the compression spring 202 are sleeved with the spring limiting sleeve 204 on the guide rod limiting connecting piece 201 and the sliding guide rod 205 respectively. Meanwhile, the upper and lower ends of the compression spring 202 are matched with the circumferential shoulders of the outer walls of the guide rod limiting connecting piece 201 and the spring limiting sleeve 204 respectively. The top end of the guide rod limiting sleeve 204 is also designed with a joint, and the joint is provided with a through hole with an axis perpendicular to the guide rod.

[0066] In the two heel elastic buffer assemblies 2 with the above-mentioned structure, the joints at the top ends of the guide rod limiting sleeves 204 are respectively located on the left and right sides of the foot frame 1, and the connecting holes on the joints are matched with the fourth light hole in the foot frame 1 to be connected through a rotating shaft to form a rotating pair. In the two heel elastic buffer assemblies 2, the joints at the bottom ends of the guide rod limiting sleeves 204 are respectively located on the left and right sides of the buffer assembly hinged seat 301b, and the connecting holes on the joints are matched with the through holes provided on the buffer assembly hinged seat 301b on the heel body 301 to be connected through a rotating shaft to form a rotating pair. Thus, the elastic buffer assembly 2, the heel assembly 3 and the foot frame 1 together form a three-link mechanism with a variable length. When the heel assembly 3 is subjected to pressure from the ground, the heel assembly 3 rotates around the rotating shaft connected with the foot frame 3, so that the two heel elastic buffer assemblies 2 are pressed to generate elastic force to play a buffering role.

[0067] In order to reduce the overall weight of the device while ensuring the structural strength and functionality of the device, the foot frame 1, the heel elastic buffer assembly 2, the heel assembly 3, the arch elastic buffer assembly 4, the arch assembly 5 and the two-degree-of-freedom toe assembly are all optimized to reduce weight. The main materials of each component are all aluminum alloy, the connecting shaft materials of the arch and the foot frame are steel, and the materials of each shaft sleeve are nylon.

[0068] This invention relates to a humanoid robot with a robotic foot that is connected to the robot's lower leg via bearing holes in the foot frame 1, forming a rotating pair. Simultaneously, a fifth optical hole is connected to the robot's ankle joint drive linkage via a rotating shaft, completing the connection with the robot's lower leg. In this invention, an inclined limiting plate 206 is designed on the rear side of the heel body 301; the inclination angle of this limiting plate 206 is the same as the inclination angle of the two shaped plates in the buffer assembly hinge seat 301b, and it is located within a groove on the rear side of the two shaped plates, with its top edge contacting the inner wall of the groove. Figure 2 As shown. Simultaneously, a cushioning rubber pad is laid on the limiting plate 206 between the two strip plates. This pad contacts the foot frame 1 during robot movement, limiting the downward displacement of the rear of the foot frame 1 and thus preventing the sliding bushings 203 on the two sets of heel elastic cushioning assemblies 2 from dislodging during robot movement. Furthermore, the limiting plate 206 reinforces the two strip plate structures, preventing them from bending downwards due to excessive force during robot movement.

[0069] The movement mechanism of the anthropomorphic mechanical foot used in this invention for humanoid robots is as follows:

[0070] (1) As Figure 1 As shown, when the heel component 2 and toe component 6 of the humanoid foot mechanical foot touch the ground at the same time, the arch elastic cushioning component 4 and heel elastic cushioning component 2 provide support for the arch component 5 and heel component 3, ensuring that the robot can be supported by the humanoid foot mechanical foot.

[0071] (2) Figure 12 As shown, when only the bottom surface of the toe component 6 of the humanoid foot touches the ground and there is a certain angle of rotation in the pitch direction relative to the ground, the toe component 6 can rotate around the pitch direction to ensure that the bottom surface is as close to the ground as possible, thereby ensuring that the humanoid robot can perform the action of the bottom surface of the toe component 6 touching the ground; when the arch component 5 is not perpendicular to the ground, the impact on the toe component 6 can still be absorbed by the arch elastic buffer component 4; when the bottom surface of the toe component 6 leaves the ground, the toe component 6 will return to its original position under the action of the torsion spring.

[0072] (3) Figure 13 As shown, when the humanoid foot has a certain angle of rotation relative to the ground in the roll direction, the bottom surfaces of the two toe components 6 will be subjected to ground reaction forces of different magnitudes. Under the combined action of the ground reaction force and the foot arch elastic buffer component 4, the two arch components 5 will rotate around the connection point of the foot frame 1 at different angles. The two toe components 6 will rotate around their respective cross axis at a certain angle to ensure that the bottom surface of the toe component 6 is in contact with the ground.

[0073] (4) Figure 14When the foot device only the heel touches the ground and has a certain angle in the pitch direction relative to the ground, the heel assembly 3 can rotate a certain angle in the pitch direction under the joint action of the ground reaction force and the heel elastic buffer assembly 2, which can make the heel bottom surface as close to the ground as possible and make the heel elastic buffer assembly 2 absorb the vibration and impact of the heel assembly 3 touching the ground.

[0074] (5) When the different bottom surfaces of the humanoid foot mechanical foot touch the ground with different sizes of force, the sheet-shaped pressure sensor of the foot bottom can provide the robot with data of whether the ground is touched and the size of the ground reaction force.

[0075] (6) When the humanoid robot applying the humanoid foot mechanical foot walks, the humanoid foot mechanical foot will switch between the states described in (1), (2) and (4) alternately and be interspersed with the state described in (3), so as to complete the straight knee and heel-toe gait.

[0076] When the humanoid robot applying the humanoid foot mechanical foot walks on unstructured ground, the pressure of the three contact surfaces on the bottom of the humanoid foot mechanical foot is not uniformly distributed, under the joint action of the non-uniform pressure and the elastic assembly, the bottom surfaces of the two toe assemblies 6 and the heel assembly 3 will each rotate a certain angle and finally reach a balanced state, and the characteristic of this balanced state is that the three bottom surfaces will respectively maintain surface contact with the ground as much as possible, thereby ensuring the friction between the foot and the ground in the case of unstructured ground.

Claims

1. A humanoid foot mechanism for a humanoid robot, characterized by: The foot frame, the heel elastic buffer assembly, the heel assembly, the arch elastic buffer assembly, the arch assembly and the toe assembly are included. The front and rear parts of the foot frame are respectively provided with the arch assembly and the heel assembly; meanwhile, the middle and rear ends of the foot frame are respectively provided with bearing holes and through holes for connecting the robot shank and the ankle joint driving assembly. The arch assembly is provided with two sets, which are arranged on the left and right sides of the foot frame; the middle parts of the two sets of arch assemblies are connected with the foot frame to form rotating pairs; the top parts of the arch assemblies are connected with the foot frame through the arch elastic buffer assembly; and the bottom parts of the arch assemblies are used for connecting the toe assembly. The toe assembly includes a toe body and a cross shaft; the bottom surface of the toe body is a plane; the front and rear opposite connecting shafts of the cross shaft are connected with the support seats fixedly installed on the toe body to form rotating pairs; when the toe assembly is subjected to normal pressure from the ground, the arch elastic buffer assembly is compressed; and the impact and vibration energy is absorbed by the compression spring. The two toe assemblies are connected with the bottom parts of the arch assemblies through the left and right opposite connecting shafts of the cross shaft to form rotating pairs; the cross shaft provides the toe assembly with roll and pitch freedom degrees; and the two roll freedom degree torsional springs and one pitch freedom degree torsional spring are used to respectively realize the reset of the roll and pitch freedom degree rotation. The two roll freedom degree torsional springs are sleeved on the front and rear rotating shafts of the cross shaft, and the rotation directions of the two roll freedom degree torsional springs are opposite; in the absence of external force, the two roll freedom degree torsional springs are used to make the bottom surface of the toe body horizontal and provide the reset of the roll freedom degree rotation of the toe assembly with torque. The pitch freedom degree torsional spring is sleeved on the left and right rotating shafts of the cross shaft; in the absence of external force, the pitch freedom degree torsional spring is used to make the toe assembly in the forward limit rotating position of the pitch freedom degree and provide the reset of the pitch freedom degree rotation of the toe assembly with torque. The bottom part of the heel assembly is a plane, and the top part is provided with joints in front and rear; the front joint is connected with the foot frame to form a rotating pair, and the rear joint is connected with the foot frame through the heel elastic buffer assembly; when the heel assembly is subjected to pressure from the ground, the heel assembly rotates around the rotating shaft connected with the foot frame, so that the two heel elastic buffer assemblies are compressed to generate elastic force and play a buffering role.

2. The anthropomorphic foot mechanism for a humanoid robot of claim 1, wherein: Five light holes are respectively arranged from front to rear on the periphery below the bearing hole of the foot frame, which are respectively a first light hole in front of the bearing hole, a second light hole below the bearing hole, a third light hole, a fourth light hole and a fifth light hole behind the bearing hole; the first light hole is used for connecting the arch assembly; the second light hole is used for connecting the arch elastic buffer assembly; the third light hole is used for connecting the heel assembly; the fourth light hole is used for connecting the heel elastic buffer assembly; and the fifth light hole is used for connecting the ankle joint driving connecting rod.

3. The anthropomorphic foot mechanism for a humanoid robot of claim 1, wherein: The toe rubber pads are arranged on the bottom surfaces of the toe body and the heel assembly; and the sheet-shaped pressure sensors are arranged between the toe body and the toe rubber pad and between the heel assembly and the rubber pad.

4. The anthropomorphic foot mechanism for a humanoid robot of claim 1, wherein: Two roll freedom torsion springs are located in the toe roll freedom torsion spring protection shell mounted on the toe body, and are separated by a partition plate; one end of each roll freedom torsion spring is placed in a one-word groove opened at the end of the connecting shaft, and the other end is in contact with the inner wall of the toe roll freedom torsion spring protection shell under the action of the pre-tightening force.

5. The anthropomorphic foot mechanism for a humanoid robot of claim 1, wherein: The pitch freedom torsion spring is located in the toe pitch freedom torsion spring protection shell fixedly installed on the inner wall of the arch assembly; one end of the pitch freedom torsion spring is placed in a one-word groove opened at the end of the connecting shaft, and the other end is in contact with the inner wall of the toe pitch freedom torsion spring protection shell under the action of the pre-tightening force.

6. The anthropomorphic foot mechanism for a humanoid robot of claim 1, wherein: The arch elastic buffer assembly comprises a limiting nut, a buffer assembly connecting shaft, two spring limiting sleeves, a compression spring, and a guide rod and a buffer assembly sliding sleeve; the guide rod is sequentially sleeved from top to bottom with two limiting nuts, a buffer assembly connecting shaft, an upper spring limiting sleeve, a compression spring, and a lower spring limiting sleeve; the buffer assembly connecting shaft is used to realize connection with the arch assembly; a joint is designed at the lower end of the guide rod to realize connection with the foot frame.

7. The anthropomorphic foot mechanism for a humanoid robot of claim 1, wherein: The heel elastic buffer assembly comprises a guide rod limiting connector, a compression spring, a spring limiting sleeve, and a sliding guide rod; the bottom end of the sliding guide rod is designed with a joint for connecting the heel body; the top end of the sliding guide rod is inserted into the cylindrical guide rod limiting connector; the compression spring is sleeved on the sliding guide rod, and the upper and lower ends of the compression spring are respectively matched with the guide rod limiting connector and the outer wall circumferential shoulder of the spring limiting sleeve; the top end of the guide rod limiting sleeve is also designed with a joint for connecting the foot frame.

8. The anthropomorphic foot mechanism for a humanoid robot of claim 1, wherein: A limiting plate is designed at the rear side of the heel body, and a buffer rubber pad is laid on the limiting plate, which is used to contact the foot frame during the movement of the robot and limit the downward displacement of the rear part of the foot frame.

9. The anthropomorphic foot mechanism for a humanoid robot of claim 1, wherein: The movement mode is as follows: (1) When the bottom surfaces of the heel assembly and the toe assembly touch the ground at the same time, the arch elastic buffer assembly and the heel elastic buffer assembly provide support force for the arch assembly and the heel assembly, so that the robot can be supported by the foot device; (2) When only the bottom surface of the toe assembly touches the ground and has a turning angle in the pitch direction relative to the ground, the toe assembly rotates around the pitch direction to ensure the adhesion of the bottom surface to the ground and realize the forefoot palm movement; when the arch assembly is not perpendicular to the ground, the impact on the forefoot palm is absorbed by the arch elastic buffer assembly; after the forefoot palm leaves the ground, the toe assembly is reset under the action of the pitch freedom torsion spring; (3) When the whole has a turning angle in the roll direction relative to the ground, the bottom surfaces of the two toe assemblies are subjected to different sizes of ground reaction force, and the two arch assemblies rotate around the foot frame connecting point under the combined action of the ground reaction force and the arch elastic buffer assembly; the two toe assemblies will rotate around their respective cross shaft axes to ensure that the bottom surface of the forefoot palm adheres to the ground. (4) When only the heel touches the ground and has a turning angle in the pitch direction relative to the ground, the heel assembly rotates around the pitch direction under the joint action of the ground reaction force and the heel elastic buffer assembly, ensuring the fit between the heel bottom surface and the ground and allowing the heel elastic buffer assembly to absorb the vibration and impact of the heel assembly when it touches the ground; (5) When touching the ground with different forces at different bottom surfaces, the sheet-shaped pressure sensor provides data on whether the ground is touched and the size of the ground reaction force; (6) When walking, the states described in (1), (2), and (4) are alternately switched, and the state described in (3) is interposed, thereby completing the straight-knee, heel-toe gait; when walking on unstructured ground, the bottom surfaces of the two toe assemblies and the bottom surface of the heel assembly will each rotate by a certain angle and eventually reach a balanced state.

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