A three-point support intelligent foot structure, a robot and a detection method

Abstract

The application relates to a three-point support intelligent foot structure, which comprises a foot mechanism and a detection mechanism, wherein the foot mechanism comprises an arch body, a cantilever slot arranged on a first side of the arch body, a first toe and a second toe rotatably connected to a second side of the arch body, and at least two groups of elastic components arranged between the first toe, the second toe and the arch body; the detection mechanism comprises a first displacement sensor and a second displacement sensor connected to the arch body, a third displacement sensor arranged on the first side of the arch body, and an inertial measurement unit connected to the arch body. The application can provide a support foot structure for a foot robot, an intelligent artificial limb and the like, can provide force information and foot position of the robot through the displacement sensor and the inertial sensor integrated in the foot, and can provide buffering for the collision between the foot and the ground through the elastic components and the cantilever beam structure, so that the force condition of the robot body is improved.

Description

Technical Field

[0001] This invention relates to the field of robotics, and in particular to a three-point support intelligent foot structure, robot, and detection method. Background Technology

[0002] In recent years, research on humanoid robots has received widespread attention, enabling them to perform various movements including walking, running, jumping, and rolling. The robot's force sensing capability is crucial for its motion control, ensuring stability and thus improving its motion performance.

[0003] In existing related technologies, such as the Chinese patent application CN116946280A, entitled "Bipedal Robot, Humanoid Robot, Robot," it is disclosed that the robot includes a body, two leg assemblies arranged on one side of the body, and a swing leg joint fixed on the other side. The swing leg joint has a horizontal swing leg rotation axis and is used to drive the leg assembly to swing around the swing leg rotation axis. The leg assembly includes a leg structure and a rotating leg joint. The rotating leg joint has a vertical swing leg rotation axis and is used to drive the leg structure to rotate around the swing leg rotation axis. The leg structure includes a thigh and a thigh joint that drives the thigh to rotate, a lower leg and a lower leg joint that drives the lower leg to rotate, and a foot and a foot joint. It can be seen that in the above-mentioned prior art, the foot structure is a whole, and the foot transmission assembly uses a crank and rocker arm. The angle between the foot and the lower leg is changed through the crank and rocker arm connected to the lower leg. It only has the main support function of the foot and cannot perceive the surrounding environment.

[0004] For example, the Chinese patent application with publication number CN111959633A and patent name "a hydraulically driven foot-type bionic humanoid robot" has a flat foot structure and its hydraulic drive unit is placed on the lower side of the calf. The ankle joint is lateral and pitched through hydraulic drive, but the foot function is limited.

[0005] Therefore, in realizing robot locomotion, current humanoid robots mainly focus on the hip-knee-ankle structure, while the foot structure itself is often neglected. For simplicity and durability, the foot mostly adopts a simple rigid structure, which only has a certain support function, but cannot provide ground force feedback, cannot provide sufficiently accurate foot-ground contact information, cannot provide reliable balance data through the foot structure, and because the rigid structure has small deformation, it cannot absorb the impact of the collision between the foot and the ground on the body during robot movement, which can easily damage the robot's main structure. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the problem that most of the existing robot feet adopt simple rigid structures, which only have a certain support function, but cannot provide ground force feedback like humans, and cannot reduce the impact of foot-ground collision on the body during movement. The present invention provides a three-point support intelligent foot structure, robot and detection method.

[0007] To address the aforementioned technical problems, this invention provides a three-point support intelligent foot structure, comprising:

[0008] A foot mechanism includes: an arch body, a cantilever groove formed on a first side of the arch body, at least two sets of first toes and second toes respectively rotatably connected to a second side of the arch body, and an elastic component disposed between each first toe and second toe and the arch body. The cantilever groove includes: a floating cavity extending through the width of the arch body, and a mounting cavity communicating with one side of the floating cavity.

[0009] The detection mechanism includes: at least two sets of first displacement sensors, second displacement sensors and at least one set of third displacement sensors respectively disposed on the arch body, the ends of the first displacement sensors and second displacement sensors being movably connected to the first toe and the second toe respectively, and the third displacement sensor being disposed in the mounting cavity and abutting against the floating cavity.

[0010] In one embodiment of the present invention, the floating cavity includes: a first groove formed on the second side of the arch body, a second groove and a third groove connected in sequence, the second groove extending from the end of the first groove toward the second side of the arch body, the third groove extending from the end of the second groove toward the first side of the arch body, and the third displacement sensor disposed above the arch body, the end of which passes through the arch body through the mounting cavity and abuts against the lower sidewall of the first groove.

[0011] In one embodiment of the present invention, the elastic component is a disc spring assembly, which is threadedly connected between each first toe or second toe and the arch body, and the disc spring assembly is disposed between the arch portion and the second pivot.

[0012] In one embodiment of the present invention, the first toe and the second toe are respectively provided with a bracket, and the first displacement sensor and the second displacement sensor are respectively provided on two sets of brackets and abut against the arch body.

[0013] In one embodiment of the present invention, at least two sets of the first displacement sensor, the second displacement sensor, and at least one set of the third displacement sensor are all LVDT displacement sensors.

[0014] The arch support is also equipped with an inertial measurement unit, which includes an accelerometer and a gyroscope.

[0015] The first toe and the second toe each include: a parallel part and an arched part connected to the end of the parallel part. The proximal end of the parallel part is rotatably connected to the arch body through a second pivot. The parallel part is also connected to the arch body through a screw, so that a floating space is formed between the parallel part and the arch body.

[0016] The ends of the first displacement sensor and the second displacement sensor are respectively movably abutted against the first toe and the second toe through a linkage mechanism. The linkage mechanism includes a first linkage assembly and a second linkage assembly. The first toe and the second toe are respectively rotatably connected to the first toe and the second toe through the first linkage assembly and the second linkage assembly. The first linkage assembly includes: a first spline passing through the first toe, a connecting rod connected to the first spline, and a pull rod connected to the first displacement sensor. The end of the connecting rod and the end of the pull rod are rotatably connected through a first rotating shaft. The second linkage assembly has the same structure as the first linkage assembly.

[0017] The present invention also discloses a robot, including the above-described three-point support intelligent foot structure.

[0018] This invention also discloses a detection method for a three-point support intelligent foot structure, used to detect the aforementioned three-point support intelligent foot structure, comprising the following steps:

[0019] Step S1: Obtain the initial coordinates of at least two sets of first and second toes in the foot structure, as well as the support points of the arch body;

[0020] Step S2: During the movement, based on the acquired initial coordinates, at least two sets of first displacement sensors and second displacement sensors are used to detect the displacement of at least two sets of first toe and second toe support points respectively, and the displacement of the arch support point is detected by a third displacement sensor to obtain the changed coordinates.

[0021] Step S3: Calculate the center of gravity projection coordinates by combining the changed coordinates and the force conditions calculated by the displacement data of each support point, and provide the equilibrium data.

[0022] In one embodiment of the present invention, the method for calculating the displacement and force relationship between the first toe and the second toe is as follows: when the toe lands, the toe fulcrum is subjected to a force F, causing the position of the toe fulcrum in the vertical direction to change by a amount Δh, thereby causing the length of the linkage mechanism to change. The first displacement sensor or the second displacement sensor detects the change in the length of the linkage Δl, and the relationship between the force F and the Δl detected by the first displacement sensor or the second displacement sensor is calibrated. The contact force between the big toe and the ground is obtained by detecting the magnitude of Δl.

[0023] The calculation method for the displacement and force relationship of the heel is as follows: When the foot structure lands, the heel fulcrum is subjected to force F', which causes a change in the vertical position of the heel fulcrum by a variable Δh', thereby changing the height of the cantilever beam. The third displacement sensor detects the change in the length of the cantilever groove by Δl'. The relationship between force F' and Δl' detected by the third displacement sensor is calibrated. The contact force between the heel and the ground is obtained by detecting the magnitude of Δl'.

[0024] Another method for calculating the relationship between heel displacement and force is as follows: The heel contacts the ground and is subjected to a uniformly distributed load. A third displacement sensor collects the displacement of the cantilever beam structure, providing displacement change data. The heel displacement can then be obtained as follows:

[0025]

[0026] In the formula, q is the uniformly distributed load, E is the elastic modulus of the material, I is the moment of inertia of the cross section, and l is the displacement change of the third sensor.

[0027] In one embodiment of the present invention, the three sets of support points are set as follows: the first toe, the second toe, and the heel of the arch body. Then, step S3 further includes the following steps: the coordinates of the first toe force point are (x1, y1, 0), and the force is F1; the coordinates of the second toe force point are (x2, y2, 0), and the force is F2; ​​the coordinates of the heel force point are (x3, y3, 0), and the force is F3. F1, F2, and F3 are all the reaction forces of the ground on the robot, and F1, F2, and F3 are calculated by the detection data of the first displacement sensor, the second displacement sensor, and the third displacement sensor, respectively.

[0028] In one embodiment of the present invention, step S3 further includes the following steps:

[0029] Let the coordinates of the center of force be (x0, y0, 0). From the equilibrium equations of an arbitrary force system in space, we get:

[0030] ∑Fi(-x0)=0(i=1,2,3)

[0031] ∑Fi(yo)=0(i=1,2,3)

[0032] By combining the above formulas, the coordinates of the centroid projection position can be obtained as (x0, y0, 0).

[0033] This invention provides a supporting foot structure for legged robots and intelligent prostheses. It can also provide force information and foot posture to the robot through displacement and inertial sensors integrated inside the foot, thereby providing the robot's center of gravity projection position and providing a reference for the robot's balance control. Furthermore, it can provide cushioning for collisions between the foot and the ground through elastic components and cantilever beam structure, improving the force situation of the robot body.

[0034] The technical solution of the present invention has the following advantages compared with the prior art:

[0035] The present invention discloses a three-point support intelligent foot structure, which forms a three-point positioning support structure through the first toe, the second toe, and the heel, so as to maintain sufficient stability of the foot structure. By setting the first displacement sensor and the second displacement sensor on the frame, the first toe and the second toe will produce a small displacement when the foot structure is subjected to force. The magnitude of the contact force between the first toe and the second toe and the ground is calculated by the obtained displacement signal. The cantilever groove makes the arch body and the heel part of the foot arch form a flexible hinge structure, which deforms when the heel is subjected to force, thereby calculating the magnitude of the contact force between the heel and the ground. The magnitude of the contact force at the first toe, the second toe, and the heel can be used to calculate the projection position of the robot's center of gravity on the ground. The elastic component and the cantilever beam structure can provide buffering for collisions between the foot and the ground, avoid the sensors directly bearing the support force of the foot and the ground, and also provide balance data for displacement and force analysis of the foot structure, so as to realize the balance control and stable walking of the humanoid robot. Attached Figure Description

[0036] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0037] Figure 1 This is a schematic diagram of the foot structure of the present invention;

[0038] Figure 2 This is a front view of the present invention;

[0039] Figure 3 This is a cross-sectional view of the foot structure of the present invention;

[0040] Figure 4 This is a schematic diagram of the linkage assembly of the present invention;

[0041] Figure 5 This is a schematic diagram of the structure of the bracket of the present invention;

[0042] Figure 6 This is a top view of the present invention;

[0043] Figure 7 This is a schematic diagram of the force applied to the toe structure of the present invention;

[0044] Figure 8 This is a schematic diagram of the force applied to the heel in this invention.

[0045] Explanation of reference numerals in the accompanying drawings: 1. Arch body; 2. First toe; 3. First link assembly; 4. Second link assembly; 5. Second toe; 6. First displacement sensor; 7. Second displacement sensor; 8. Frame; 9. Inertial measurement unit; 10. Floating cavity; 101. First groove; 102. Second groove; 103. Third groove; 104. Elastic hole; 11. Disc spring assembly; 12. Parallel part; 13. Arch-shaped part; 14. Extension part; 15. Arch body; 16. Heel; 17. Third displacement sensor; 18. Connecting rod; 19. Pull rod; 20. Second spline; 21. Bracket; 22. Mounting cavity; 23. First mounting beam; 24. Second mounting beam; 25. First pivot; 26. Second pivot; 27. Elastic washer; 28. Screw. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0047] Example 1

[0048] Reference Figure 1-8 As shown, a three-point support smart foot structure of the present invention includes:

[0049] A foot mechanism includes: an arch body 1, a cantilever groove formed on a first side of the arch body 1, at least two sets of first toes 2 and second toes 5 respectively rotatably connected to a second side of the arch body 1, and an elastic component disposed between each first toe 2 and second toe 5 and the arch body 1. The cantilever groove includes: a floating cavity 10 extending through the width of the arch body 1, and a mounting cavity 22 communicating with one side of the floating cavity 10.

[0050] The detection mechanism includes: at least two sets of first displacement sensors 6 and second displacement sensors 7 respectively disposed on the arch body 1, and at least one set of third displacement sensors 17. The ends of the first displacement sensors 6 and second displacement sensors 7 are movably connected to the first toe 2 and the second toe 5 respectively. The third displacement sensor 17 is disposed on the mounting cavity 22 and abuts against the floating cavity 10. One end of the third displacement sensor 17 is mounted on the mounting cavity 22, and the other end is connected to the wall of the floating cavity 10 away from the mounting cavity 22, so that the third displacement sensor 17 is connected to both sides of the floating cavity 10, thereby measuring the floating displacement of the floating cavity 10.

[0051] The present invention discloses a three-point support intelligent foot structure. Through a floating cavity 10, the arch body 1 is divided into a heel 16 portion that contacts the ground for support, and an arch body 15 portion that connects to the first toe 2 and the second toe 5 respectively. The first toe 2, the second toe 5, and the heel 16 form a three-point positioning support structure. By setting a first displacement sensor 6 and a second displacement sensor 7 on the frame 8, the foot structure causes slight displacements in the first toe 2 and the second toe 5 when subjected to force. The displacements of the first toe 2 and the second toe 5 respectively drive the first displacement sensor 6 and the second displacement sensor 7 to produce displacements. The displacement sensors output displacement signals, and the magnitude of the contact force between the first toe 2 and the second toe 5 and the ground is calculated from the obtained displacement signals. The cantilever groove 10 allows the foot... The bow body 15 and the heel part of the bow body 1 form a flexible hinge structure, which causes the heel 16 to deform when subjected to force. The deformation of the heel 16 is detected by the third displacement sensor 17, thereby calculating the magnitude of the contact force between the heel 16 and the ground. The projection position of the robot's center of gravity on the ground can be calculated by obtaining the contact force at the first toe 2, the second toe 5 and the heel 16, thus providing balance data for the foot structure. In conjunction with the inertial measurement unit 9, which is equipped with a three-axis accelerometer and a three-axis gyroscope and is mounted at the center of mass of the structure, it is used to sense the changes in velocity and angular velocity of the foot structure and the foot posture, providing support for the balance control and stable walking of the humanoid robot. When there are more toes, such as three, four, five, or six, a corresponding number of displacement sensors can also be set for data acquisition.

[0052] See Figure 4 , Figure 5As shown, the ends of the first displacement sensor 6 and the second displacement sensor 7 are movably abutted against the first toe 2 and the second toe 5 respectively via a linkage mechanism. The linkage mechanism includes a first linkage assembly 3 and a second linkage assembly 4. The first toe 2 and the second toe 5 are rotatably connected to the first toe 2 and the second toe 5 respectively via the first linkage assembly 3 and the second linkage assembly 4. The first linkage assembly 3 includes: a first spline passing through the first toe 2, a connecting rod 18 connected to the first spline, and a pull rod 19 connected to the first displacement sensor 6. A second spline 20 is provided on the frame 8. The first displacement sensor 6 and the second displacement sensor 7 are connected to the frame 8 via the second spline 20. The ends of the connecting rod 18 and the pull rod 19 are connected by a first rotating shaft 25. The second link assembly 4 and the first link assembly 3 are structurally identical. When the user walks, the position and force distribution of the toes will be different with each step. The first and second displacement sensors 7 monitor the displacement of the toes in real time and feed this data back to the foot structure control system in real time. After receiving the data from the displacement sensors, the control system calculates the adjustment command through a preset algorithm. This algorithm not only considers the current gait information, but also makes real-time optimization adjustment decisions based on the user's walking speed, direction changes, and different ground conditions, such as flat, inclined, and unstable conditions. During walking, the arch body 1 not only bears the task of supporting the weight, but also makes adaptive adjustments to its shape according to changes in the walking environment, such as ground hardness and inclination.

[0053] The inertial measurement unit (IMU) monitors the foot's movement in all directions, including acceleration and rotation angle. This data together constitutes a deep understanding of the user's walking state and provides data support for adjusting the foot's structure and posture.

[0054] See also Figure 4As shown, in another embodiment, the first toe 2 and the second toe 5 are respectively provided with brackets 21. The first displacement sensor 6 and the second displacement sensor 7 are respectively provided on the two sets of brackets 21 and abut against the arch body 1. The first displacement sensor 6, the second displacement sensor 7 and the third displacement sensor 17 are any one of LVDT displacement sensor, potentiometer displacement sensor, inductive displacement sensor, synchro, capacitive displacement sensor, eddy current displacement sensor and Hall effect displacement sensor terminal. In this embodiment, LVDT sensor is preferred. The first displacement sensor 6 and the second displacement sensor 7 are respectively provided on the first toe 2 and the second toe 5. Each set of brackets 21 is provided with two positioning seats. The two positioning seats fix the two sides of a first displacement sensor 6 or a second displacement sensor 7. Specifically, the first displacement sensor 6 or the second displacement sensor 7 passes through the positioning seat and the movable end abuts against the arch body 1. The positioning seat is also provided with a retaining ring to limit and lock the corresponding sensor to prevent rotation. It can be set according to the actual situation. The first and second displacement sensors 7 are provided on the first and second toes 5 and abut against the arch body 1, or are provided on the arch and abut against the first and second toes 5 through a connecting rod assembly.

[0055] See Figures 1-3 As shown, both the first toe 2 and the second toe 5 include: a parallel portion 12 and an arched portion 13 connected to the end of the parallel portion 12. The proximal end of the parallel portion 12 is rotatably connected to the arch body 1 via a second pivot 26. The parallel portion 12 is also connected to the arch body 1 via a screw 28, forming a floating space between the parallel portion 12 and the arch body 1. A disc spring assembly 11 is provided between the parallel portion 12 and the arch body 1. The disc spring assembly 11 is located between the arched portion 13 and the second pivot 26. Between 6, the first side of the arch body 1 has an extension 14, and the lower edge of the end of the extension 14 also has a flange extending downward. The flange stops the disc spring. The extension 14 and the parallel part 12 are arranged in parallel and located above the parallel part 12. The disc spring is set in the floating space. The parallel part 12 forms a rotation support point through the second rotating shaft 26. When the arch is compressed, it presses down on the toes. The toes rotate upward on the space extension 14 under the support force of the ground. The disc spring is set to buffer between the parallel part 12 and the extension 14.

[0056] See Figure 1 , Figure 2 , Figure 5As shown, the floating cavity 10 includes: a first groove 101 formed on the second side of the arch body 1, a second groove 102 and a third groove 103 connected in sequence. The second groove 102 extends from the end of the first groove 101 toward the second side of the arch body 1, and the third groove 103 extends from the end of the second groove 102 toward the first side of the arch body 1. The third displacement sensor 17 is disposed above the arch body 1, and its end passes through the arch body 1 and abuts against the lower sidewall of the first groove 101. The first groove 101, the second groove 102 and the third groove 103 form an S-shaped continuous groove structure. The S-shaped continuous groove structure penetrates the width of the arch body 1 but does not penetrate... The length of the arch body 1 is specified, and an elastic hole 104 is opened at the end of the third groove 103, extending through the width of the arch body 1. The elastic hole 104 is cylindrical or elliptical. The cantilever groove 10 provides an elastic floating space between the arch body 1 and the heel 16. The elastic force is provided by the deformation between the arch body 15 and the heel 16. A mounting cavity 22 is also provided on the second side of the arch body 1. A first mounting beam 23 is connected inside the mounting cavity 22. A third displacement sensor 17 is installed on the first mounting beam 23 and abuts against the bottom wall of the first groove 101. A second mounting beam 24 is provided on the first side of the arch body 1, and a second rotating shaft 26 is installed on the second mounting beam 24.

[0057] Example 2

[0058] The present invention also discloses a robot comprising the above-described three-point support intelligent foot structure.

[0059] The robot disclosed in this embodiment walks by using a three-point support intelligent foot structure and provides walking balance data for the robot to adjust its posture.

[0060] The robot disclosed in this embodiment, in addition to its intelligent foot structure, is equipped with a multi-jointed flexible arm for performing complex manipulation tasks, mimicking the fine movements of a human arm and hand. The arm joints utilize high-precision servo motors to ensure the accuracy and repeatability of the movements. A control system processes data from various sensors, including foot displacement sensors and an inertial measurement unit (IMU) 9, as well as other environmental perception sensors such as cameras and infrared sensors. The control system makes decisions based on this data to control the robot's movement and behavior. Furthermore, an integrated sensor system is included: in addition to the sensors within the foot structure, the robot is equipped with various sensors, such as vision sensors (cameras), tactile sensors, temperature sensors, and sound sensors, enabling comprehensive environmental perception. Employing machine learning algorithms, the robot can optimize its walking strategy and task execution methods based on past experience, improving its adaptability and work efficiency in unknown environments.

[0061] To further enhance the robot's performance and adaptability, each foot joint is driven by a drive system such as a servo motor, servo cylinder, or hydraulic system, including a miniature drive motor for the toes. Control commands are issued by the control system to simulate the complexity and flexibility of human foot movements, ensuring a high degree of dynamic response and accuracy of foot movements, enabling the robot to quickly adapt to different ground conditions.

[0062] In addition to the drive system, the foot structure integrates elastic elements (such as elastic materials and springs) that mimic the natural elasticity of the human foot, providing additional energy storage and release mechanisms for the robot's gait. This design helps increase walking efficiency and reduce energy consumption, especially when crossing obstacles or walking on uneven ground. In this embodiment, the cantilever groove 10 corrects the arch 15 and heel 16 to form a flexible hinge structure. Elastic pads 27 are also provided below the heel 16, the first toe 2, and the second toe 5. The elastic elements are rubber pads, silicone pads, etc. The elastic pads 27 are bonded or embedded in the heel 16, the first toe 2, and the second toe 5, with the lower end protruding from the embedded part. This provides elasticity to the contact surface and can also amplify the displacement of the displacement sensor. The elastic pads 27 of the heel 16 are located at the rear of the heel 16, concentrating the force on the heel at the rear of the heel and amplifying the displacement changes of the cantilever beam structure.

[0063] Through dynamic adjustments of the foot arch body 1 and toes, the robot can adjust its foot posture in real time according to changes in ground contact during walking, thereby maintaining stability. The adjustment data is obtained through real-time analysis from displacement sensors and inertial measurement units 9 (accelerometers and gyroscopes). For example, when walking on unstable or sloping ground, the robot can automatically adjust the corresponding angle of its toes, which not only increases the ground contact area but also improves grip and balance. Combining sensor data of the foot structure and the robot's environmental perception system, the central processing unit can generate highly adaptive gait to optimize walking efficiency and stability. This includes adopting a softer landing method on soft surfaces or dynamically adjusting stride length and stride height on irregular ground. By utilizing the elastic elements of the foot, some kinetic energy is recovered and converted into electrical energy during each step, or stored in the elastic elements for use in the next step. This energy recovery mechanism enables the robot to use energy more efficiently and extend its working time in environments without external energy supply.

[0064] Example 3

[0065] This invention also discloses a detection method for a three-point support intelligent foot structure, applicable to detecting the three-point support intelligent foot structure described in Embodiment 1, comprising the following steps:

[0066] Step S1: Obtain the initial coordinates of at least two sets of first toes 2 and second toes 5 in the foot structure, as well as the support points of the arch body 1;

[0067] Step S2: During the movement, based on the acquired initial coordinates, at least two sets of first displacement sensors 6 and second displacement sensors 7 are used to detect the displacement of at least two sets of first toe 2 and second toe 5 support points respectively, and the third displacement sensor 17 is used to detect the displacement of the support point of the arch body 1 to obtain the changed coordinates.

[0068] Step S3: Calculate the center of gravity projection coordinates by combining the changed coordinates and the force conditions calculated by the displacement data of each support point, and provide the equilibrium data.

[0069] This embodiment discloses a detection method for a three-point support intelligent foot structure. The system first needs to acquire the coordinates of the three support points of the foot structure, which is usually achieved by embedding displacement sensors within the foot structure. These sensors can monitor the positional changes of the three support points in real time. The inertial measurement unit 9 (IMU) integrated in the foot includes an accelerometer and a gyroscope. In this embodiment, it is a three-axis accelerometer and a three-axis gyroscope, which can accurately measure the tilt angle, rotation angle, and acceleration of the foot structure. Through comprehensive analysis of these data, the robot can understand its absolute position and relative posture in space in real time, providing basic data for subsequent balance adjustment. Using the data obtained from the displacement sensors and combined with the physical model of the foot structure, the system can calculate and evaluate the force on each support point. The system analyzes the magnitude of the supporting force and assesses the force changes caused by the robot's own weight, movements, or external environment (such as slopes or uneven ground). Through real-time analysis of the force at each support point, the system can accurately assess the force balance of the foot structure, providing a basis for subsequent movement adjustments. By combining the force at the support points and the posture data of the foot structure, the system dynamically calculates the projected position of the center of gravity on the ground. Mathematical models and algorithms, such as dynamic weight allocation algorithms, are used to adjust the center of gravity position in real time to adapt to different movement states and ground conditions. Determining the projected position of the center of gravity not only ensures the robot's stability but also optimizes its movement efficiency, reduces energy consumption, and provides a real-time feedback mechanism for balance data. After obtaining the projected position of the center of gravity, the system further analyzes the posture changes of the foot structure and compares them with the expected balance state to provide balance data. This data is fed back to the robot's central control unit, which adjusts the robot's movement strategy in real time according to the preset balance algorithm, including adjusting body posture and gait changes, to maintain the robot's balance and stability. Detection methods such as PID control and fuzzy logic control are used to achieve further dynamic balance adjustments.

[0070] Let the three sets of support points be: the first toe 2, the second toe 5, and the heel 16 of the foot arch body 1. Then, step S2 further includes the following steps: let the coordinates of the force point of the first toe be (x1, y1, 0) and the force be F1; let the coordinates of the force point of the second toe be (x2, y2, 0) and the force be F2; let the coordinates of the force point of the heel 16 be (x3, y3, 0) and the force be F3. F1, F2, and F3 are all the reaction forces of the ground on the robot. F1, F2, and F3 are calculated by the detection data of the first displacement sensor 6, the second displacement sensor 7, and the third displacement sensor 17, respectively.

[0071] A simplified diagram of the toe structure is shown below. Figure 7 As shown, the first toe 2 is the big toe. The first and second toes have an angle between them, working in conjunction with the second toe 5 to detect forces in both directions. Since the structures of the first toe 2 and the second toe 5 are similar, only the big toe is analyzed. Link AC represents the first toe 2 and the connecting rod 18 fixed to it. Link AB with a sliding joint represents the LVDT displacement sensor and the rotating panel. BC represents the heel. AB, AC, and BC are hinged together. When the toe touches the ground, the fulcrum A is subjected to a force F, causing a change in the vertical displacement Δh of point A. This changes the length of link AB, and the LVDT displacement sensor detects the change in Δl. Therefore, the change in Δl is related to the magnitude of force F. By calibrating the relationship between force F and the displacement Δl detected by the LVDT, the contact force between the first toe 2 and the ground can be obtained by detecting the magnitude of Δl.

[0072] When the toes land, the fulcrum of the first toe 2 and the second toe 5 is subjected to a force F, causing a change in the vertical position of the toe fulcrum by a quantity Δh. This results in a change in the length of the linkage mechanism. The first displacement sensor 6 or the second displacement sensor 7 detects the change in length Δl of the first linkage assembly 3 or the second linkage assembly 4. The relationship between the force F and the Δl detected by the first displacement sensor 6 or the second displacement sensor 7 is calibrated. By detecting the magnitude of Δl, the contact force between the first toe 3 or the second toe 4 and the ground is obtained. Due to the force F acting on the first toe 3 and the second toe 5, the contact force between the first toe 3 and the second toe 4 and the ground is determined. 4. The foot arch body 1 is connected to the second pivot 26. Therefore, the displacement direction of the first toe 3 and the second toe 4 relative to the foot arch body is determined, that is, they rotate around the pivot point. Thus, the displacement of the first toe 3 and the second toe 4 and the magnitude of the force are uniquely determined. A corresponding force and displacement mapping table or database can be established. Alternatively, a mapping function can be built into the control system to determine the force on the first toe 3 and the second toe 4. By independently analyzing and comparing the magnitude of the force on the second toe, the first toe 3, and the heel 16, the force direction of the foot structure can be obtained.

[0073] When a linkage mechanism is not used, the first displacement sensor 3 or the second displacement sensor 4 detects the change in the length of the linkage Δl, calibrates the relationship between the force F and Δl detected by the first displacement sensor or the second displacement sensor, and obtains the contact force between the big toe and the ground by detecting the magnitude of Δl.

[0074] The calculation method for the displacement and force relationship of the heel is as follows: When the foot structure lands, the heel fulcrum is subjected to a force F', causing a change in the vertical position of the heel fulcrum by a variable Δh'. This results in a change in the height of the cantilever beam. The third displacement sensor detects the change in the length of the cantilever groove by Δl'. The relationship between the force F' and the Δl' detected by the third displacement sensor is calibrated. The contact force between the heel and the ground is obtained by detecting the magnitude of Δl'.

[0075] In some embodiments, the method for calculating the displacement and force relationship of the heel is as follows: the heel touches the ground and is subjected to a uniformly distributed load. The third displacement sensor 17 collects the displacement between the bow body 15 and the heel 16, providing displacement change data. The displacement of the heel 16 can be obtained as follows:

[0076]

[0077] In the formula, q is the uniformly distributed load, l is the displacement change of the third sensor, E is the elastic modulus of the material, and I is the moment of inertia of the cross section.

[0078] Step S3 also includes the following steps:

[0079] Let the coordinates of the center of force be (x0, y0, 0). From the equilibrium equations of an arbitrary force system in space, we get:

[0080] ∑F(-xo)=0(i=1,2,3)

[0081] ∑Fi(yo)=0(i=1,2,3)

[0082] By combining the above formulas, the numerical values ​​of the centroid projection position coordinates (x0, y0, 0) can be obtained.

[0083] The first toe 2 and the second toe 5 extend downward in a direction away from the arch body 1. The arch body 1 extends downward in a direction away from the first toe 2 and the second toe 5. The first toe 2, the second toe 5 and the arch body 1 form a three-point support structure. The inertial measurement unit 9 is located at the center of mass of the foot structure. The end of the screw 28 is threaded with a limit nut. The end of the second rotating shaft 26 is provided with a locking ring.

[0084] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A three-point support intelligent foot structure, characterized in that, include: A foot mechanism includes: an arch body, a cantilever groove formed on a first side of the arch body, at least two sets of first toes and second toes respectively rotatably connected to a second side of the arch body, and an elastic component disposed between each first toe and second toe and the arch body. The cantilever groove includes: a floating cavity extending through the width of the arch body, and a mounting cavity communicating with one side of the floating cavity. The detection mechanism includes: at least two sets of first displacement sensors, second displacement sensors and at least one set of third displacement sensors respectively disposed on the arch body, the ends of the first displacement sensors and second displacement sensors being movably connected to the first toe and the second toe respectively, and the third displacement sensor being disposed in the mounting cavity and abutting against the floating cavity.

2. The three-point support intelligent foot structure according to claim 1, characterized in that: The floating cavity includes: a first groove formed on the second side of the arch body, a second groove and a third groove connected in sequence, the second groove extending from the end of the first groove toward the second side of the arch body, the third groove extending from the end of the second groove toward the first side of the arch body, and the third displacement sensor disposed above the arch body, with its end passing through the arch body through the mounting cavity and abutting against the lower side wall of the first groove.

3. The three-point support intelligent foot structure according to claim 1, characterized in that: The first toe and the second toe are respectively equipped with a first displacement sensor or a second displacement sensor via a bracket or a linkage mechanism; When installed using the bracket method: the first toe and the second toe are respectively provided with brackets, and the first displacement sensor and the second displacement sensor are respectively provided on the two sets of brackets and abut against the arch body. When installed via the linkage mechanism: the ends of the first displacement sensor and the second displacement sensor are respectively movably abutted against the first toe and the second toe via the linkage mechanism. The linkage mechanism includes a first linkage assembly and a second linkage assembly. The first toe and the second toe are respectively rotatably connected to the first toe and the second toe via the first linkage assembly and the second linkage assembly. The first linkage assembly includes: a first spline passing through the first toe, a connecting rod connected to the first spline, and a pull rod connected to the first displacement sensor. The end of the connecting rod and the end of the pull rod are rotatably connected via a first rotating shaft. The second linkage assembly has the same structure as the first linkage assembly.

4. The three-point support intelligent foot structure according to claim 1, characterized in that: At least two sets of the first displacement sensor, the second displacement sensor, and at least one set of the third displacement sensor are any one of LVDT displacement sensor, potentiometer displacement sensor, inductive displacement sensor, synchro, capacitive displacement sensor, eddy current displacement sensor, and Hall effect displacement sensor. The foot arch body is also provided with an inertial measurement unit, which includes an accelerometer and a gyroscope.

5. A three-point support intelligent foot structure according to claim 1 or 2, characterized in that: The first toe and the second toe each include: a parallel part and an arched part connected to the end of the parallel part. The proximal end of the parallel part is rotatably connected to the arch body through a second pivot. The parallel part is also connected to the arch body through a screw, so that a floating space is formed between the parallel part and the arch body.

6. The three-point support intelligent foot structure according to claim 5, characterized in that: The elastic component is a disc spring assembly, which is threadedly connected between each first or second toe and the arch body, and is disposed between the arch portion and the second pivot.

7. A robot, characterized in that, Including a three-point support smart foot structure as described in any one of claims 1-6.

8. A detection method for a three-point support intelligent foot structure, characterized in that: The method for detecting a three-point support smart foot structure as described in any one of claims 1-6 includes the following steps: Step S1: Obtain the initial coordinates of at least two sets of first and second toes in the foot structure, as well as the support points of the arch body; Step S2: During the movement, based on the acquired initial coordinates, at least two sets of first displacement sensors and second displacement sensors are used to detect the displacement of at least two sets of first toe and second toe support points respectively, and the displacement of the arch support point is detected by a third displacement sensor to obtain the changed coordinates. Step S3: Calculate the center of gravity projection coordinates by combining the changed coordinates and the force conditions calculated by the displacement data of each support point, and provide the equilibrium data.

9. The detection method for a three-point support intelligent foot structure according to claim 8, characterized in that: The calculation method for the displacement and force relationship of the first and second toes is as follows: When the toes land, the toe fulcrum is subjected to force F, which causes the position of the toe fulcrum in the vertical direction to change by a certain amount Δh, thereby causing the length of the linkage mechanism to change. The first displacement sensor or the second displacement sensor detects the change in the length of the linkage Δl. The relationship between force F and Δl detected by the first displacement sensor or the second displacement sensor is calibrated. The contact force between the big toe and the ground is obtained by detecting the magnitude of Δl. The calculation method for the displacement and force relationship of the heel is as follows: When the foot structure lands, the heel fulcrum is subjected to force F', which causes a change in the vertical position of the heel fulcrum by a variable Δh', thereby changing the height of the cantilever beam. The third displacement sensor detects the change in the length of the cantilever groove by Δl'. The relationship between force F' and Δl' detected by the third displacement sensor is calibrated. The contact force between the heel and the ground is obtained by detecting the magnitude of Δl'.

10. The detection method for a three-point support intelligent foot structure according to claim 8, characterized in that: Assuming the three support points are: the first toe, the second toe, and the heel of the arch, then step S3 further includes the following step: Let the coordinates of the force-bearing point of the first toe be ( The magnitude of the force is The coordinates of the point of force application on the second toe are ( ,), the magnitude of the force is The coordinates of the point where the heel bears the force are ( The magnitude of the force is , All are the reaction forces of the ground on the robot. F1, F2, and F3 are calculated using the detection data from the first, second, and third displacement sensors, respectively. Step S3 also includes the following steps: Let the coordinates of the center of force be ( From the equilibrium equations of an arbitrary force system in space, we obtain: （i=1,2,3） （i=1,2,3） By combining the above formulas, the coordinates of the centroid projection position can be obtained as ( ).

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