Variable-stiffness self-adaptive toe joint and biped robot

Abstract

The variable-stiffness self-adaptive toe joint comprises a sole plate and toes located on the front side of the sole plate, the bottom of the sole plate and the bottoms of the toes are located on the same horizontal plane, one side of each toe is installed on the sole plate through a titanium steel plate spring, a pressing wheel is arranged above the titanium steel plate spring, and the other side of each toe is installed on the sole plate. The variable stiffness of the titanium steel plate spring can be adjusted by adjusting the position of the pressing wheel above the titanium steel plate spring. One side of the toe is connected with the sole plate through the titanium steel plate spring, the pressing wheel is located above the titanium steel plate spring and can press the titanium steel plate spring, and the driving mechanism can drive the pressing wheel to move along the titanium steel plate spring; the bending radius when the toes are stressed is changed through different contact positions of the pressing wheels and the titanium steel plate springs on the toes, variable-rigidity self-adaptive movement of the toes in the movement process is achieved, and the walking speed, the stride height and stride of the robot in the walking process and the walking stability of the robot are improved.

Description

Technical Field

[0001] The utility model relates to the field of biped robot manufacturing, in particular to a variable-rigidity self-adaptive toe joint and a biped robot. Background Art

[0002] Bipedal robots are a hot topic in robotics research. After decades of development, many bipedal robots capable of stable walking have emerged worldwide. However, compared to humans, these robots still lag far behind in gait, walking speed, and walking stability.

[0003] Traditional bipedal robot designs often overlook the role of the feet in walking. Typical robot legs have 12 degrees of freedom, with each leg having six degrees of freedom. The foot is composed of the entire sole, making it difficult to achieve a heel-on-toes-off walking pattern. Furthermore, even slightly uneven surfaces can cause irregular contact between the sole and the ground, affecting the stability of the humanoid robot. Only the entire sole of the foot can be placed parallel to the ground, resulting in very slow walking speeds. Because each foot is a single unit, it cannot rotate around the front of the foot during walking, especially with larger strides. This accelerates the movement of the knee joint, increasing the leg's swing amplitude and causing unstable movement.

[0004] For example, the patent publication number is CN107128398A, and the patent name is a multi-joint leg structure of a bipedal walking robot. It specifically discloses "including a foot movement mechanism, an ankle joint movement mechanism, and a leg joint movement mechanism. The toe joint is hinged to the foot through an axis, the lower leg joint bracket is hinged to the inner bracket through an axis, and the inner bracket is hinged to the ankle joint support plate. The foot movement mechanism can control the toe joint to lift the toes around the axis hinged to the foot, thereby realizing the toe lifting movement; the ankle joint movement mechanism can control the foot to swing left or right, and can also control The footplate is controlled to move forward or backward, realizing that the robot's footplate joint can move with multiple degrees of freedom; the leg joint motion mechanism can control the calf joint to lift the leg clockwise or counterclockwise, and can also control the calf to rotate around the thigh, realizing that the robot's leg joint can lift the leg and walk bipedally with multiple degrees of freedom. Although the above technology can rotate the footplate around the toes, the distance between the toes and the footplate is fixed, and the bending range of the two is limited, which limits the robot's walking speed, the height it can cross and the stride length, as well as the stability of the robot when walking. Utility Model Content

[0005] The technical problem to be solved by the utility model is: how to improve the walking speed, the traversable height and the stride of the robot during walking, and improve the walking stability of the robot.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A variable-rigidity adaptive toe joint includes a sole plate and a toe located on the front side of the sole plate, wherein the sole plate and the bottom of the toe are on the same horizontal plane, wherein one side of the toe is mounted on the sole plate via a titanium leaf spring, and a pressure wheel is provided above the titanium leaf spring, and the variable stiffness of the titanium leaf spring can be adjusted by adjusting the position of the pressure wheel above the titanium leaf spring.

[0008] The present application connects the toe to the sole of the foot through a titanium leaf spring on one side, and the pressure wheel is located above the titanium leaf spring and can press the titanium leaf spring. The driving mechanism can drive the pressure wheel to move along the titanium leaf spring. The different contact positions between the pressure wheel and the titanium leaf spring on the toe change the bending radius of the toe when it is under force, thereby realizing variable stiffness adaptive movement of the toe during movement, thereby improving the walking speed, traversable height and stride of the robot during walking, as well as the walking stability of the robot.

[0009] As a further solution of the present invention: a rotation gap is reserved between the toes and the sole of the foot.

[0010] As a further solution of the present invention: the titanium steel leaf spring is a plate-shaped structure made of titanium steel and can be bent, and a titanium steel plate mounting hole connected to the foot plate is opened at the end of the titanium steel leaf spring.

[0011] As a further solution of the present invention: pressure wheel blocks are installed on both sides of the top of the sole plate, wherein the two ends of the pressure wheel can be movably connected in the two pressure wheel blocks, and the driving mechanism can drive the pressure wheel to roll back and forth along the direction of the two pressure wheel blocks.

[0012] As a further solution of the present invention: a driving mechanism capable of driving the pressure wheel to move is installed above the sole.

[0013] As a further solution of the present invention: the driving mechanism includes a motor holder installed on the sole plate, wherein a motor is installed on the motor holder, and the output end of the motor is connected to a crank through a reducer, one end of the crank is connected to the end of the connecting rod, and the other end of the connecting rod is connected to one end of the pressure wheel.

[0014] As a further solution of the present invention: a pressure wheel roller groove corresponding to the pressure wheel is opened on the inner side of the pressure wheel block, and a pressure wheel center axis groove corresponding to the pressure wheel center axis is opened on the side of the pressure wheel roller groove facing away from the pressure wheel.

[0015] As a further solution of the present invention: the height of the pressure wheel center axis groove is lower than the height of the pressure wheel roller groove.

[0016] The utility model also discloses a biped robot, comprising the variable stiffness adaptive toe joint.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. This application connects one side of the toe to the sole of the foot via a titanium leaf spring. A pressure wheel is located above the titanium leaf spring and can press the titanium leaf spring. A driving mechanism can drive the pressure wheel to move along the titanium leaf spring. The bending radius of the toe when subjected to force is changed by the different contact positions between the pressure wheel and the titanium leaf spring on the toe, thereby achieving variable stiffness adaptive movement of the toe during movement, thereby improving the walking speed, traversable height and stride length of the robot during walking, as well as the walking stability of the robot.

[0019] 2. The variable stiffness adaptive toe joint speed reduction mechanism of this application uses a worm gear mechanism to enable self-locking when the toe is subjected to force while increasing the output torque of the motor;

[0020] 3. The variable stiffness adaptive toe joint involved in this application uses an elastic titanium steel leaf spring as the toe structure. When the toe is subjected to external force, it will adaptively bend and automatically return to its original shape when the force is removed.

[0021] 4. This application can archive the distance between the toe and the pressure wheel, so that when the pressure wheel position is adjusted later, the relationship between the pressure wheel position and the toe bending radius can be clearly understood in a timely manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of a variable stiffness adaptive toe joint according to an embodiment of the present utility model;

[0023] Figure 2 This is a front view of the variable stiffness adaptive toe joint according to an embodiment of the present utility model;

[0024] Figure 3 This is a schematic structural diagram of the toe and titanium leaf spring of an embodiment of the utility model;

[0025] Figure 4 An exploded view of the variable stiffness adaptive toe joint according to an embodiment of the present utility model;

[0026] Figure 5 This is a top view of the variable stiffness adaptive toe joint according to an embodiment of the present utility model;

[0027] Description of reference numerals:

[0028] 1. Driving mechanism; 11. Motor; 12. Reducer; 13. Crank; 14. Connecting rod; 15. Motor holder;

[0029] 2. Driven mechanism; 21. Pressing wheel block; 22. Pressing wheel; 23. Pressing wheel center axis groove; 24. Pressing wheel roller groove;

[0030] 3. Toe; 31. Titanium leaf spring; 32. Titanium plate mounting hole;

[0031] 4. Foot plate; 41. Bottom plate mounting hole. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0033] Example 1

[0034] Reference Figure 1 、 Figure 2 and Figure 5 A variable stiffness adaptive toe joint includes a driving mechanism 1, a driven mechanism 2, a toe 3 and a sole plate 4, wherein the toe 3 is installed at the front end of the sole plate 4, and the driven mechanism 2 and the driving mechanism 1 are installed on the top of the sole plate 4.

[0035] For ease of understanding and description, Figure 1 The side of the midfoot sole plate 4 facing the toe 3 is the front, and the rest of the directions are based on this as a reference. It should be understood that this direction setting is only for the convenience of description and understanding, and cannot be understood as a limitation of the present invention.

[0036] Reference Figure 1 、 Figure 2 and Figure 4 The driving mechanism 1 includes a motor 11, a reducer 12, a crank 13, a connecting rod 14 and a motor holder 15, wherein the motor 11 and the reducer 12 are both installed above the sole plate 4 through the motor holder 15; wherein the motor holder 15 is provided with three groups, each group is a conical structure, and the bottom can be welded or fastened to the sole plate 4 by bolts or pins, the motor 11 and the reducer 12 are fixed between the three motor holders 15, the output shaft of the motor 11 is connected to the reducer 12, and the output shaft of the reducer 12 is connected to the crank 13 located on the top side of the sole plate 4, wherein the crank 13 is fan-shaped as a whole, and one end of the connecting rod 14 is movably connected to the tip of the fan, and the arc portion of the fan is connected to the reducer 12; and the other end of the connecting rod 14 is connected to the pressure wheel 22 located in the driven mechanism 2.

[0037] It should be noted that the reducer 12 contains a worm gear mechanism, which achieves reverse self-locking and only allows movement in one direction. The power is output to the crank 13 through the reducer 12, and the crank 13 drives the other end of the connecting rod 14 to move back and forth in a straight line.

[0038] In summary, the working principle here is as follows: by controlling the operation of the motor 11, the motor 11 can drive the crank 13 to rotate through the reducer 12, and when the crank 13 rotates, it can drive the connecting rod 14 to perform circular motion, and then the power transmitted from the crank 13 to the connecting rod 14 pulls the pressure wheel 22 to achieve lateral movement.

[0039] The driving mechanism 1 of the present application adopts the combination of a crank connecting rod and a motor to convert circular motion into linear motion of the pressure wheel 22; and a linear cylinder or other method can also be selected to achieve the linear motion of the pressure wheel 22. The present application does not limit this method and only gives one of the optimal implementation methods.

[0040] Reference Figure 1 、 Figure 2 and Figure 4 The driven mechanism 2 includes a pressure wheel block 21, a pressure wheel 22, a pressure wheel center axis groove 23 and a pressure wheel roller groove 24;

[0041] Two groups of pressure wheel blocks 21 are provided, which are fixed on both sides of the top of the sole plate 4 respectively, and the pressure wheel 22 is located between the two pressure wheel blocks 21 and can roll forward and backward between the two pressure wheel blocks 21. The two groups of pressure wheel blocks 21 are arranged horizontally, and a pressure wheel roller groove 24 is provided on the inner side of each pressure wheel block 21. The pressure wheel 22 can roll and move in the pressure wheel roller groove 24. A pressure wheel center axis groove 23 is provided on the side of the pressure wheel roller groove 24 facing away from the center of the pressure wheel 22. It should be noted that the height of the pressure wheel center axis groove 23 is less than the height of the pressure wheel roller groove 24.

[0042] The pressure wheel 22 as a whole is composed of rollers of three diameters. The pressure wheel roller of the outermost circle has the largest diameter, and the pressure wheel center axis roller of the innermost circle has the smallest diameter. When the pressure wheel 22 is located between the two sets of pressure wheel blocks 21, the pressure wheel roller of the outermost circle can just press the titanium steel leaf spring 31 installed on the sole plate 4, and the middle roller is just located in the pressure wheel roller groove 24, and the pressure wheel center axis roller with the smallest diameter is just located in the pressure wheel center axis groove 23; therefore, when the pressure wheel 22 is driven by the driving mechanism 1 to roll forward or backward, the pressure wheel center axis roller can roll in the pressure wheel center axis groove 23, the middle roller can roll in the pressure wheel roller groove 24, and the pressure wheel roller of the outermost circle can roll on the titanium steel leaf spring.

[0043] Reference Figure 1 and Figure 3, the rear end of the toe 3 is provided with an integrated titanium steel leaf spring 31, the bottom of the toe 3 is horizontal, the top is arc-shaped, and a certain bending gap is left between the toe 3 and the sole plate 4 to prevent the bending between the toe 3 and the sole plate 4 from being affected; the titanium steel leaf spring 31 is arranged at the rear end root of the toe 3, the titanium steel leaf spring has a certain elasticity, is made of titanium steel material and can be bent, and the overall deformation can be restored. A titanium steel plate mounting hole 32 is opened on the side of the titanium steel leaf spring 31 away from the toe 3, and the titanium steel plate mounting hole 32 can be directly fixed to the bottom plate mounting hole 41 on the sole plate 4 by a threaded connection such as a bolt;

[0044] Let H be the distance between the toe 3 and the pressure wheel 22; the larger the H value, the larger the rotation radius of the toe 3 and the smaller the stiffness of the titanium leaf spring 31; the smaller the H value, the smaller the rotation radius of the toe 3 and the larger the stiffness of the titanium leaf spring 31. By varying the contact position between the pressure wheel 22 and the titanium leaf spring 31, the bending radius of the toe 3 when subjected to force is changed, achieving variable stiffness adaptive movement of the toe during movement. Adjustment of this variable stiffness means adjusting the rotation radius of the toe 3 relative to the sole 4, and thus the walking speed, stride height, and stride length of the robot during walking.

[0045] Reference Figure 1 The sole plate 4 is a plate-shaped structure as a whole, and its bottom is flush with the bottom of the toe 3.

[0046] Example 2

[0047] The utility model also discloses a bipedal walking robot, the bipedal walking robot adopts the variable stiffness adaptive toe joints in Example 1. When walking, the bending radius of the toe joints when subjected to force can be adjusted in real time as needed, thereby realizing variable stiffness adaptive movement of the toes during movement.

[0048] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A variable stiffness adaptive toe joint, comprising a sole plate (4) and a toe (3) located on the front side of the sole plate (4), characterized in that: The sole plate (4) and the bottom of the toe (3) are on the same horizontal plane, wherein one side of the toe (3) is mounted on the sole plate (4) via a titanium steel leaf spring (31), and a pressure wheel (22) is provided above the titanium steel leaf spring (31). By adjusting the position of the pressure wheel (22) above the titanium steel leaf spring (31), the variable stiffness of the titanium steel leaf spring (31) can be adjusted.

2. The variable stiffness adaptive toe joint according to claim 1, characterized in that: A rotation gap is reserved between the toes (3) and the sole (4).

3. The variable stiffness adaptive toe joint according to claim 1, characterized in that: The titanium steel plate spring (31) is a plate-shaped structure made of titanium steel and can be bent. A titanium steel plate mounting hole (32) connected to the foot plate (4) is provided at the end of the titanium steel plate spring (31).

4. The variable stiffness adaptive toe joint according to claim 1, characterized in that: Pressure wheel blocks (21) are installed on both sides of the top of the sole plate (4), wherein the two ends of the pressure wheel (22) can be movably connected in the two pressure wheel blocks (21), and a driving mechanism (1) capable of driving the pressure wheel (22) to move is installed above the sole plate (4); the driving mechanism (1) can drive the pressure wheel (22) to roll back and forth along the direction of the two pressure wheel blocks (21).

5. The variable stiffness adaptive toe joint according to claim 4, characterized in that: The driving mechanism (1) includes a motor holder (15) mounted on the sole plate (4), wherein a motor (11) is mounted on the motor holder (15), an output end of the motor (11) is connected to a crank (13) via a reducer (12), one end of the crank (13) is connected to the end of a connecting rod (14), and the other end of the connecting rod (14) is connected to one end of a pressure wheel (22).

6. The variable stiffness adaptive toe joint according to claim 4, characterized in that: A pressing wheel roller groove (24) corresponding to the pressing wheel (22) is provided on the inner side of the pressing wheel block (21), and a pressing wheel center axis groove (23) corresponding to the pressing wheel center axis is provided on the side of the pressing wheel roller groove (24) facing away from the pressing wheel (22).

7. The variable stiffness adaptive toe joint according to claim 6, characterized in that: The height of the pressing wheel center axis groove (23) is lower than the height of the pressing wheel roller groove (24).

8. A bipedal robot, characterized in that: It comprises the variable stiffness adaptive toe joint as described in any one of claims 1-7.

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