A foot structure and humanoid robot
By using a combination of carbon fiber plates and lightweight foam layers in the foot structure of the humanoid robot, the weight and noise problems of the foot structure are solved, achieving better shock absorption and stability, making it suitable for various environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING HUMANOID ROBOTICS INNOVATION CENTER CO LTD
- Filing Date
- 2025-08-08
- Publication Date
- 2026-07-24
AI Technical Summary
In existing technologies, the foot structure of humanoid robots generates significant impact and noise when lifting their legs to land, and is also quite heavy, affecting usage scenarios and stability.
Carbon fiber plates are used as the base plate, combined with a lightweight foam layer as the shock-absorbing middle layer. The thickness gradually increases along the rear end of the foot and is fixed by adhesive to increase the contact area with the ground and reduce the risk of the center of gravity lifting. High-strength wear-resistant rubber plates are used as the base plate, in conjunction with the shell for protection.
It effectively reduces the weight and cost of the foot structure, while improving shock absorption, reducing foot noise, increasing friction, preventing slippage, and making it suitable for more scenarios.
Smart Images
Figure CN224546153U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of robots, and more specifically, to a foot structure and humanoid robot. Background Technology
[0002] In recent years, with the surge in demand for robots in human-inhabited scenarios such as services, healthcare, and homes, humanoid robots have gradually moved from laboratory prototypes to small-scale commercial applications. As the only continuous point of contact between a bipedal humanoid robot and the ground, the performance of the leg structure directly determines the overall dynamic stability, walking lifespan, and safety redundancy of the robot.
[0003] Currently, most humanoid robots use a combination of metal and rubber for their foot structure. When the foot lifts and lands, it comes into contact with the ground, resulting in a large impact. Rubber has limited contractility, so its cushioning and shock absorption effect is poor. At the same time, the robot's feet constantly hitting the ground can produce a lot of noise, which is not conducive to use in some environments. Utility Model Content
[0004] This application provides a foot structure and a humanoid robot that can improve the foot's shock absorption capacity, thereby reducing foot noise.
[0005] Firstly, this application provides a foot structure, employing the following technical solution:
[0006] A foot structure, comprising:
[0007] Base plate;
[0008] The script board is used to connect to the robot body.
[0009] The shock-absorbing intermediate layer is disposed between the foot body plate and the bottom plate, and has shock absorption and sound absorption properties. The thickness of the shock-absorbing intermediate layer gradually increases from the front end of the foot to the rear end of the foot.
[0010] Optionally, the upper surface of the shock-absorbing intermediate layer is fixedly connected to the base plate by adhesive bonding, and the lower surface of the shock-absorbing intermediate layer is fixedly connected to the base plate by adhesive bonding.
[0011] Optionally, the robot body has an ankle adapter, and the script body plate has a connector near the rear end of the foot, the connector having mounting holes for connecting with the ankle adapter.
[0012] Optionally, the foot structure further includes a housing, which is provided with a clearance groove for avoiding the ankle adapter; the housing is located on the side of the foot plate away from the shock-absorbing middle layer, and the housing covers the foot plate.
[0013] Optionally, the script body plate is provided with a mounting groove, and the outer peripheral edge of the housing is located in the mounting groove and fixedly connected to the script body plate.
[0014] Optionally, the base plate is configured as a high-strength, wear-resistant rubber sheet.
[0015] Optionally, the script body plate is configured as a carbon fiber plate.
[0016] Optionally, the shock-absorbing intermediate layer is configured as a lightweight foam layer.
[0017] Optionally, the front and rear ends of the base plate are respectively provided with arc surfaces, and the distance between the arc surfaces and the shock-absorbing intermediate layer gradually decreases along the direction from the center of the foot towards the front and rear ends.
[0018] Secondly, this application provides a humanoid robot, which adopts the following technical solution:
[0019] A humanoid robot includes a robot body and a foot structure as described above.
[0020] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:
[0021] The shock-absorbing middle layer has certain shock absorption and sound absorption properties. When the robot steps on the ground and its feet are impacted, the shock-absorbing middle layer can contract to achieve a shock absorption effect, thereby reducing the impact on the robot body, improving the shock absorption capacity of the foot structure, and thus reducing the noise of stepping on the ground, making the robot suitable for more scenarios. Secondly, the way the shock-absorbing middle layer is set up so that the robot's center of gravity is in the middle of the entire foot structure, preventing the front end from lifting up, increasing the contact area with the ground, thereby increasing friction and preventing slippage. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.
[0023] Figure 1 This is a schematic diagram of the overall structure of a foot structure disclosed in an embodiment of this application;
[0024] Figure 2 This is a cross-sectional view of a foot structure disclosed in an embodiment of this application.
[0025] Explanation of reference numerals in the attached figures:
[0026] 1. Base plate; 11. Curved surface; 2. Base plate; 21. Connector; 22. Mounting hole; 23. Mounting groove; 3. Shock-absorbing middle layer; 4. Shell; 41. Clearance groove. Detailed Implementation
[0027] The present application will be further described in detail below with reference to the accompanying drawings.
[0028] This application provides a foot structure and a humanoid robot that can effectively reduce the weight and cost of the robot's feet, while improving the foot's shock absorption capacity, thereby reducing foot noise.
[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all of them. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.
[0030] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0031] Currently, most humanoid robots use a combination of metal and rubber for their foot structure. This structure is heavy, and both metal processing and rubber manufacturing require high costs. Secondly, the foot makes contact with the ground during the lifting and landing process, resulting in a large impact. Rubber has limited contractility, so the cushioning and shock absorption effect is poor. At the same time, the robot's feet constantly hitting the ground can generate a lot of noise, which is not conducive to use in some environments.
[0032] To address the aforementioned technical problems, this application discloses a foot structure and a humanoid robot. Please refer to [link / reference]. Figure 1and Figure 2 This is one embodiment of the foot structure in this application. The foot structure includes a base plate 1, a script body plate 2, and a shock-absorbing intermediate layer 3. The base plate 1 is used to contact the ground, the script body plate 2 is used to connect with the robot body, and the shock-absorbing intermediate layer 3 has shock absorption and sound absorption properties, and the shock-absorbing intermediate layer 3 is disposed between the script body plate 2 and the base plate 1.
[0033] In this embodiment, the script body plate 2 is configured as a carbon fiber plate, the shock-absorbing middle layer 3 is configured as a lightweight foam layer, and the shock-absorbing middle layer 3 is preferably made of EVA material.
[0034] Understandably, carbon fiber sheets have an areal density only 1 / 3 that of aluminum alloys and 1 / 5 that of steel, yet provide equal or even higher bending stiffness. The lightweight foam layer includes supercritical foaming materials such as ETPU, EVA, and PEBA, which have low density and are over 90% hollow, providing 60% to 70% compression stroke with almost no increase in mass. EVA is cheaper than ETPU, making it suitable for mass production in consumer robots. Traditional metal sheets require stamping, welding, and five-axis machining, resulting in complex tooling. Compared to existing technologies that combine metal sheets with a rubber interlayer, the carbon fiber sheet in this application only requires edge trimming and drilling, simplifying tooling and reducing processing time. The foamed core material can be cut in one sheet, laser-formed in a single cut, and scraps can be recycled and re-foamed, resulting in high material utilization. Therefore, the combination of carbon fiber plates and lightweight foam layers can effectively reduce the weight of the foot structure. On the other hand, the manufacturing process of carbon fiber and lightweight foam layers is simple, which can effectively reduce costs. Secondly, the shock-absorbing middle layer 3 has certain shock absorption and sound absorption properties. When the robot steps on the ground and its feet are impacted, the shock-absorbing middle layer 3 can shrink to achieve a shock absorption effect, thereby reducing the impact on the robot body, improving the shock absorption capacity of the foot structure, and thus reducing the noise of stepping on the ground, making the robot suitable for more scenarios.
[0035] To achieve the connection between the script body plate 2 and the robot body, the robot body has an ankle adapter. A connector 21 is located near the rear end of the foot on the script body plate 2. The connector 21 has mounting holes 22 for connecting to the ankle adapter. The ankle adapter connects to the connector 21 through the mounting holes 22, thereby securing it to the script body plate 2.
[0036] Because the robot's ankle is located at the rear of the foot plate 1, it is prone to issues such as the rear of the foot contracting, the front lifting up, or even slipping. Therefore, the thickness of the shock-absorbing middle layer 3 gradually increases from the front to the rear of the foot. The upper surface of the foot body plate 2 and the shock-absorbing middle layer 3 have the same tilt angle. It is understandable that the shock-absorbing middle layer 3 has a certain slope, which keeps the robot's center of gravity in the middle of the entire foot structure, preventing the front from lifting up, increasing the contact area with the ground, and thus increasing friction to prevent slipping.
[0037] Specifically, the thickness of the rear end of the damping intermediate layer 3 is H, and the inclination angle of the upper surface of the damping intermediate layer 3 is θ. In this embodiment, the core parameters can be obtained through multivariate orthogonal experiments combined with the reinforcement learning model of the operation and control system for iterative optimization. The specific determination process is as follows:
[0038] S1. Define the range of basic parameters.
[0039] Based on robot motion data, such as step frequency and center of gravity transfer rate, the initial thickness range of the rear end of the shock-absorbing middle layer 3 is set to 5-25mm, and the tilt angle range of the upper surface of the shock-absorbing middle layer 3 is set to 0.5°-5°, covering the motion characteristics of robots with a typical weight of 50-100kg.
[0040] S2. Reinforcement learning simulation test.
[0041] Using the vibration reduction efficiency η and energy feedback coefficient κ of the motion control system as core indicators, the system was trained through over 1000 virtual scenarios.
[0042] When the thickness H of the rear end of the damping middle layer 3 increases, the damping efficiency η increases nonlinearly. When H=15mm, the damping efficiency η reaches its peak value of 82%. However, at this time, the energy feedback coefficient κ will decrease, affecting the continuity of motion.
[0043] When the tilt angle θ of the upper surface of the damping middle layer 3 increases, the energy feedback coefficient κ increases significantly, but the damping efficiency η decreases sharply after θ>2°.
[0044] In actual implementation, the rear thickness H of the damping middle layer 3 and the tilt angle θ of the upper surface of the damping middle layer 3 can be determined by the core indicator requirements of the specific application scenario.
[0045] In this embodiment, the upper surface of the damping intermediate layer 3 is fixedly connected to the base plate 2, and the lower surface of the damping intermediate layer 3 is fixedly connected to the base plate 1. The base plate 2, the damping intermediate layer 3, and the base plate 1 have the same shape and size. Specifically, the upper surface of the damping intermediate layer 3 is bonded to the base plate 2, and the lower surface of the damping intermediate layer 3 is bonded to the base plate 1, so that there is no relative slippage between the base plate 1 and the base plate 2. The entire foot structure, from top to bottom, consists of the base plate 2, the full-surface adhesive layer, the damping intermediate layer 3, the full-surface adhesive layer, and the base plate 1, forming a continuous force column without slippage. The impact load is transmitted downward in the form of surface pressure, and the lateral shear component is uniformly absorbed by the adhesive layer. At the same time, due to the absence of bolt holes and notches, the force lines do not detour, and the local maximum principal stress of the base plate 1 decreases, avoiding the edge stress concentration that occurs in traditional point connections, thus improving fatigue life. Secondly, the adhesive layer itself is a viscoelastic material, which continues to dissipate residual energy in the micro-vibration stage, playing a secondary damping role.
[0046] The base plate 1 is configured as a high-strength, wear-resistant rubber plate, giving it wear resistance and anti-slip properties. This allows the robot's foot structure to achieve reliable grip in complex terrain while maintaining a long lifespan and low maintenance costs during high-frequency use. In other embodiments, the base plate 1 can be configured with different performance characteristics to meet the needs of different scenarios.
[0047] Furthermore, the front and rear ends of the base plate 1 are respectively provided with curved surfaces 11, and the distance between the curved surfaces 11 and the shock-absorbing intermediate layer 3 gradually decreases along the direction from the center of the foot towards the front and rear ends. The curved surfaces 11 at the front and rear ends of the base plate 1 can touch or lift off the ground before the main body of the base plate 1 when the robot walks or lifts its feet, avoiding the rigid flat bottom from directly scraping against ground protrusions, step edges or gaps, reducing the risk of falling. Secondly, the curved surfaces 11 allow the center of gravity to transition continuously between the ball of the foot and toes or heel and ball of the foot, prolonging the impact time, thereby reducing the impact effect.
[0048] The foot structure also includes a housing 4, which protects the footplate 2 and the connecting piece 21. The housing 4 has a clearance groove 41 for avoiding the ankle adapter. The housing 4 is located on the side of the footplate 2 away from the shock-absorbing intermediate layer 3 and covers the footplate 2. The footplate 2 has a mounting groove 23, and the outer peripheral edge of the housing 4 is located within the mounting groove 23 and is fixedly connected to the footplate 2. It can be understood that after the edge of the housing 4 is embedded in the mounting groove 23, it forms an inverted U-shaped cross section with the footplate 2, which is equivalent to adding a continuous reinforcing rib around the footplate 2, improving the bending stiffness. At the same time, the mounting groove 23 provides 360° radial positioning, and the housing 4 can be pressed in, eliminating the need for multiple positioning pins and hole alignment steps in the traditional method.
[0049] This application also discloses a humanoid robot, which includes a robot body and the aforementioned foot structure. Since the humanoid robot adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.
[0050] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A foot structure, characterized in that, include: Base plate; The script board is used to connect to the robot body. The shock-absorbing intermediate layer is disposed between the foot body plate and the bottom plate, and has shock absorption and sound absorption properties. The thickness of the shock-absorbing intermediate layer gradually increases from the front end of the foot to the rear end of the foot.
2. The foot structure according to claim 1, characterized in that, The upper surface of the shock-absorbing intermediate layer is fixedly connected to the base plate by adhesive bonding, and the lower surface of the shock-absorbing intermediate layer is fixedly connected to the base plate by adhesive bonding.
3. The foot structure according to claim 1, characterized in that, The robot body has an ankle adapter, and the script body plate has a connector near the rear end of the foot. The connector has mounting holes for connecting with the ankle adapter.
4. The foot structure according to claim 3, characterized in that, The foot structure also includes a housing, which is provided with a clearance groove for avoiding the ankle adapter; the housing is located on the side of the foot body plate away from the shock-absorbing middle layer, and the housing covers the foot body plate.
5. The foot structure according to claim 4, characterized in that, The script body plate is provided with a mounting groove, and the outer peripheral edge of the housing is located in the mounting groove and is fixedly connected to the script body plate.
6. The foot structure according to claim 1, characterized in that, The base plate is configured as a high-strength, wear-resistant rubber sheet.
7. The foot structure according to claim 1, characterized in that, The script body plate is configured as a carbon fiber plate.
8. The foot structure according to claim 1, characterized in that, The shock-absorbing intermediate layer is configured as a lightweight foam layer.
9. The foot structure according to claim 1, characterized in that, The base plate has arc surfaces at both the front and rear ends, and the distance between the arc surfaces and the shock-absorbing intermediate layer gradually decreases along the direction from the center of the foot towards the front and rear ends.
10. A humanoid robot, characterized in that, It includes the robot body and the foot structure as described in any one of claims 1 to 9.