Foot structure of robot

Abstract

The embodiment of the invention relates to the technical field of robots, and discloses a robot foot structure which comprises a driving mechanism, a sole plate, an ankle, a transmission hinge and a sole elastic element. Wherein the front sole and the rear sole of the sole plate are hinged through a transmission hinge; a rear foot plate is placed on the ankle; the sole elastic element is arranged on the lower surface of the sole plate; the driving mechanism is arranged on the upper surface of the sole plate and comprises a motor, a transmission push rod, a transmission connecting shaft, a transmission connecting rod and a driven shaft; a motor arranged on the rear foot plate is connected with one end of a transmission push rod, the other end of the transmission push rod is connected with a first end of a transmission connecting rod through a transmission connecting shaft, and a second end of the transmission connecting rod is connected with the front foot sole through a driven shaft. The motor drives the transmission push rod to move, and the transmission push rod drives the front sole to rotate around the transmission hinge through the transmission connecting shaft, the transmission connecting rod and the driven shaft. In this way, toes are accurately controlled, self-locking is formed by toe parts of the foot of the robot according to different requirements, and therefore the foot action of the robot is kept.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of robots, and particularly to a foot structure of a robot. Background Art

[0002] Biped robots are an important direction in the field of robot research. After decades of development, biped robots capable of achieving stable gaits have emerged in many countries. However, compared with humans, there are still significant gaps in gait, walking speed, stability, etc. In traditional biped robot designs, the key role of the foot in walking is usually overlooked. Generally, the foot of a robot is regarded as a whole, and it is difficult to achieve the walking mode of heel strike and toe off in a human-like gait. In addition, even slightly uneven ground may cause uneven contact between the sole and the ground, thus affecting the gait stability of the humanoid robot.

[0003] In the prior art, the robot's sole is parallel to the ground, resulting in a slow walking speed. Since each foot is a whole, it is impossible to rotate the foot around the front end during walking. Especially when the stride is large, this will cause the knee joint to accelerate, thus increasing the swing amplitude of the leg and resulting in unstable gait. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a foot structure of a robot, which can accurately control the movement of the toes, adjust the force and speed according to different walking requirements, so as to provide flexible and stable support during the gait cycle, and at the same time enable the toe components of the robot's foot to form self-locking, so as to maintain the foot movement of the robot.

[0005] To solve the above technical problems, an embodiment of the present invention provides a foot structure of a robot, including a driving mechanism (1), a foot sole plate (2), an ankle (3), a transmission hinge (4), and a sole elastic element (5); wherein, the front sole (21) and the rear sole (22) of the foot sole plate (2) are hinged by the transmission hinge (4); the ankle (3) places the rear sole (22); the sole elastic element (5) is arranged on the lower surface of the foot sole plate (2); the driving mechanism (1) is arranged on the upper surface of the foot sole plate (2), and includes a motor (13), a transmission push rod (12), a transmission connecting shaft (14), a transmission connecting rod (11), and a driven shaft (15); wherein, the motor (13) arranged on the rear sole (22) is connected to one end of the transmission push rod (12), the other end of the transmission push rod (12) is connected to the first end of the transmission connecting rod (11) through the transmission connecting shaft (14), and the second end of the transmission connecting rod (11) is connected to the front sole (21) through the driven shaft (15); the motor (13) drives the transmission push rod (12) to move, and the transmission push rod (12) drives the front sole (21) to rotate around the transmission hinge (4) through the transmission connecting shaft (14), the transmission connecting rod (11), and the driven shaft (15).

[0006] Compared with the prior art, the embodiment of the present invention adopts a foot structure including a driving mechanism (1), a foot sole plate (2), an ankle (3), a transmission hinge (4), and a sole elastic element (5). In the present invention, the driving mechanism (1) is composed of a motor (13), a transmission push rod (12), a transmission connecting shaft (14), a transmission connecting rod (11), and a driven shaft (15). The motor (13) drives the transmission push rod (12) to perform a linear motion. The transmission push rod (12) is hinged to the transmission connecting rod (11) through the transmission connecting shaft (14), and the other end of the transmission connecting rod (11) drives the front sole (21) to rotate around the transmission hinge (4) through the driven shaft (15). Through the cooperation of the motor (13), the transmission push rod (12), and the transmission connecting rod (11), the independent movement of the front sole (21) is realized. Thanks to the driving mechanism (1) of the present invention, within a limited space, the "push-pull" action is realized through the combination of the motor (13) and the transmission push rod (12) to provide a greater driving force, so that the foot of the robot forms a self-locking, thereby maintaining the foot movement of the robot.

[0007] In some embodiments, the foot structure at least includes multiple groups of the driving mechanisms (1) arranged in parallel, and any group of the driving mechanisms (1) is arranged perpendicular to the transmission hinge (4) in space.

[0008] In some embodiments, the foot structure includes 2 groups of the driving mechanisms (1) arranged in parallel, which are respectively arranged on the left and right sides of the foot structure.

[0009] In some embodiments, one end of the transmission push rod (12) is provided with a lead screw (131) that mates with the motor (13). A ball screw is formed between the lead screw (131) and the rotor of the motor (13) through balls. The motor (13) drives the transmission push rod (12) to move through the ball screw.

[0010] In some embodiments, the connecting shaft (14) and the driven shaft (15) are respectively embedded in the shaft holes at both ends of the transmission link (11). A revolute pair is formed between the transmission link (11) and the transmission push rod (12) through a transmission connecting shaft (14), and a revolute pair is formed between the transmission link (11) and the front foot sole (21) through the driven shaft (15), so that the motor (13) drives the transmission push rod (12) and drives the front foot sole (21) to rotate around the transmission hinge (4) through the transmission link (11).

[0011] In some embodiments, the output axis of the motor (13) is collinear with the movement directions of the transmission push rod (12) and the transmission link (11).

[0012] In some embodiments, the ankle (3) includes an ankle boss (31) and a six-axis force sensor (32) integrated on the ankle boss (31). Among them, the six-axis force sensor (32) is fixedly parallel to the upper surface of the rear foot plate (22). The ankle boss (31) is connected to the leg of the robot.

[0013] In some embodiments, the ankle boss (31) is provided with an ankle joint support plate (311), and the ankle joint support plate is provided with a shaft hole (312) for fixing the leg connecting shaft of the robot.

[0014] In some embodiments, the transmission hinge (4) includes an upper hinge (41) fixed to the front foot sole (21) and a lower hinge (42) fixed to the rear foot plate (22). A revolute pair is formed between the upper hinge (41) and the lower hinge (42) through a transmission rotating shaft.

[0015] In some embodiments, the sole elastic element (5) includes a front foot sole pad (51) and a rear foot plate pad (52). Among them, the front foot sole pad (51) is fixed to the bottom surface of the front foot sole (21), and the rear foot plate pad (52) is fixed to the bottom surface of the rear foot plate (22). Description of the Drawings

[0016] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the drawings in the figures do not constitute a scale limitation.

[0017] Figure 1 It is a schematic structural diagram of a robot foot according to an embodiment of the present invention;

[0018] Figure 2 It is another schematic structural diagram of a robot foot according to an embodiment of the present invention

[0019] Figure 3 It is a schematic structural diagram of a driving mechanism of a robot foot according to an embodiment of the present invention;

[0020] Figure 4 It is a schematic structural diagram of a motor involved in a driving mechanism of a robot foot according to an embodiment of the present invention;

[0021] Figure 5 It is a schematic structural diagram of a foot sole plate of a robot foot according to an embodiment of the present invention;

[0022] Figure 6 It is a schematic structural diagram of an ankle of a robot foot according to an embodiment of the present invention;

[0023] Figure 7 It is another schematic diagram of an ankle structure of a robot foot according to an embodiment of the present invention;

[0024] Figure 8 It is a schematic structural diagram of a transmission hinge of a robot foot according to an embodiment of the present invention;

[0025] Figure 9 It is a schematic diagram of a sole elastic element of a robot foot according to an embodiment of the present invention. Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0028] In addition, if there are descriptions such as "first" and "second" in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions 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 required by the present invention.

[0029] In order to solve the problems of the existing entire sole touching the ground in parallel, the contact between the sole and the ground being irregular, and affecting the stability of the humanoid robot, etc., the present invention provides a foot structure for a robot. Figures 1 to 7 A preferred embodiment of the foot structure of the robot provided by the present invention is shown.

[0030] Please refer to Figure 1 and Figure 2 In this embodiment, a foot structure of a robot is involved. The foot structure includes a driving mechanism (1), a foot sole (2), an ankle (3), a transmission hinge (4), and a sole elastic element (5); wherein, the front sole (21) and the rear sole (22) of the foot sole (2) are hinged through the transmission hinge (4); the ankle (3) places the rear sole (22); the sole elastic element (5) is arranged on the lower surface of the foot sole (2); the driving mechanism (1) is arranged on the upper surface of the foot sole (2) and includes a motor (13), a transmission push rod (12), a transmission connecting shaft (14), a transmission connecting rod (11), and a driven shaft (15); wherein, the motor (13) arranged on the rear sole (22) is connected to one end of the transmission push rod (12), the other end of the transmission push rod (12) is connected to the first end of the transmission connecting rod (11) through the transmission connecting shaft (14), and the second end of the transmission connecting rod (11) is connected to the front sole (21) through the driven shaft (15); the motor (13) drives the transmission push rod (12) to move, and the transmission push rod (12) drives the front sole (21) to rotate around the transmission hinge (4) through the transmission connecting shaft (14), the transmission connecting rod (11), and the driven shaft (15). Thus, through the combined action of the motor (13), the transmission push rod (12), and the transmission connecting rod (11), the independent movement of the front sole (21) is achieved. Moreover, due to the use of the transmission structure of the motor (13) and the transmission push rod (12), a greater force can be provided by the "push-pull" action in a limited space to maintain the movement of the robot, enabling the foot of the robot to form self-locking. At the same time, a motor with a small volume and light weight can be used to reduce the inertia during the leg movement and save space.

[0031] Specifically, the driving mechanism (1) includes a transmission connecting rod (11), a transmission push rod (12), a motor (13), a transmission connecting shaft (14), and a driven shaft (15). The motor (13) is fixed on the foot sole (2) as a power source, and the flexible movement of the toes is achieved through precise control. One end of the transmission push rod (12) is provided with a lead screw (131), and power is transmitted between the lead screw (131) and the motor (13) through a ball screw. The motor (13) transmits power to the balls, and the balls transmit the power to the lead screw (131) at one end of the transmission push rod (12). The driving force and bearing capacity are greatly enhanced through the movement of the ball screw. The other end of the transmission push rod (12) is connected to the transmission connecting shaft (14), and the transmission connecting shaft (14) is driven to move back and forth by the transmission push rod (12) to ensure the smoothness of the movement. Both ends of the transmission connecting rod (11) are respectively connected to the transmission connecting shaft (14) and the driven shaft (15). The driven shaft (15) is connected to the front sole (21) of the foot sole (2) and is responsible for transmitting the motor power to the toes to achieve the active movement of the toes. In this way, through the integration of components such as the driving mechanism, foot sole, ankle, transmission hinge, and foot sole elastic element, precise control of the movement of the robot toes is achieved, which not only improves the speed, crossing height, and stride of the robot during walking, but also enhances the walking stability and is applicable to complex and changeable terrain environments.

[0032] In some embodiments, the foot structure at least includes multiple groups of the driving mechanisms (1) arranged in parallel, and any one of the driving mechanisms (1) is arranged perpendicular to the transmission hinge (4) in space.

[0033] Specifically, please refer to Figure 1 , in one embodiment, the foot structure includes 2 groups of the driving mechanisms (1) arranged in parallel, which are respectively arranged on the left and right sides of the foot structure.

[0034] In some embodiments, please refer to Figure 3 and Figure 4 , one end of the transmission push rod (12) is provided with a lead screw (131) that cooperates with the motor (13). A ball screw is formed between the lead screw (131) and the rotor of the motor (13) through balls, and the motor (13) drives the transmission push rod (12) to move through the ball screw.

[0035] Specifically, the motor (13) transmits power to the ball, and the ball then transmits the power to one end of the transmission push rod (12) through the ball screw. Due to the function of the ball screw, the driving force and the bearing capacity are greatly enhanced. The transmission push rod (12) is driven by the ball screw to move back and forth, ensuring the smoothness of the movement. The use of the ball screw design not only enhances the driving force and the bearing capacity but also ensures the smoothness of the movement. Further, the cooperation between the ball screw and the transmission push rod effectively transmits the power to the transmission connecting shaft, and then drives the transmission link to move, realizing the active bending and stretching of the toes, significantly improving the flexibility and functionality of the robot foot, and enabling it to adapt to various complex terrains and movement requirements. During the whole process, the smoothness of the movement and the effective transmission of the force are ensured, and the bearing capacity of the system is also enhanced.

[0036] Different from the related technology in which the driving motor rotates to drive the transmission rod to rotate around the bearing axis, so that the foot plate rotates clockwise or counterclockwise around the axis, the present invention adopts the transmission structure of the motor (13) and the transmission push rod (12). In this structure, within a limited space, a greater force is provided through the "push-pull" action to maintain the movement of the robot, making the robot foot form a self-locking. In addition, the use of a motor with a small volume and light weight can reduce the inertia in the leg movement, thus saving space.

[0037] Please refer to Figures 1 to 4 , in some embodiments, the connecting shaft (14) and the driven shaft (15) are respectively embedded in the shaft holes at both ends of the transmission link (11); the transmission link (11) and the transmission push rod (12) form a revolute pair through the transmission connecting shaft (14), and the transmission link (11) and the front foot sole (21) form a revolute pair through the driven shaft (15), so that the motor (13) drives the transmission push rod (12), and drives the front foot sole (21) to rotate around the transmission hinge (4) through the transmission link (11).

[0038] Specifically, after the connecting shaft (14) passes through the transmission push rod (12), it is placed in the shaft hole at one end of the transmission link (11); the driven shaft (15) is placed in the shaft hole at the other end of the transmission link (11) and fixed on the support plate of the front foot sole (21). Through this structure, the transmission link (11) drives the front foot sole (21) to rotate around the transmission hinge (4). Thus, the linear motion of the motor is converted into a rotational motion through the transmission link (11), pushing the front foot sole (21) to rotate around the transmission hinge (4), completing the transmission and amplification of the movement, and significantly improving the movement efficiency.

[0039] In this structure, the driven shaft (15) in the driving mechanism (1) plays a crucial role in effectively transmitting power to the forefoot (21). When power is transmitted to the forefoot (21) through the driven shaft (15), it triggers relative movement between the forefoot (21) and the rear footplate (22). This movement is the core of the working mechanism of the sole (2), ensuring the flexibility and efficiency of the sole function. With this design, the forefoot (21) and the rear footplate (22) can achieve precise relative displacement according to requirements, thus meeting different gait and movement needs. Please refer to Figure 1 and Figure 5 , the sole (2) includes a plurality of positioning holes for the components of the above-mentioned foot structure to be fixed to the positioning holes of the sole (2) by means of snap-fitting, riveting, screwing, etc.

[0040] Please refer to Figure 3 and Figure 4 , in some embodiments, the output axis of the motor (13) is collinear with the movement directions of the transmission push rod (12) and the transmission link (11).

[0041] Specifically, the motor (13) converts the rotational motion of the motor into the linear motion of the push rod through the lead screw (131) installed in the inner tube. The transmission push rod (12) is connected to the lead screw (131) to achieve translation along the output axis of the motor (13), and the transmission link (12) further drives the transmission link (11) to rotate around the connecting shaft (14) through the connecting shaft (14). In this way, when the axes are collinear, the rotational power output by the motor can be directly converted into the linear motion of the push rod or the link, thereby optimizing the power transmission path, reducing energy loss, reducing mechanical stress, and improving the synchronization accuracy. This design not only ensures the transmission efficiency but also extends the service life of the equipment, meeting the common reliability design principles in mechanical systems.

[0042] In some embodiments, please refer to Figure 1 , Figure 6 and Figure 7 , the ankle (3) includes an ankle boss (31) and a six-axis force sensor (32) integrated on the ankle boss (31); wherein, the six-axis force sensor (32) is fixedly parallel to the upper surface of the rear footplate (22); the ankle boss (31) is connected to the leg of the robot.

[0043] Furthermore, in some embodiments, the ankle boss (31) is provided with two ankle joint support plates, and the ankle joint support plates are provided with shaft holes (312) for fixing the leg connecting shaft of the robot.

[0044] Specifically, the ankle (3) includes an ankle boss (31) and a six-axis force sensor (32). The ankle boss (31) is an important connecting component between the leg structure and the foot, and is also a core component of the ankle joint movement. The six-axis force sensor (32) is responsible for real-time monitoring of the torque and force borne by the ankle, and can accurately feedback the force condition of the ankle, providing necessary data support and accurate feedback information for the control system, so as to achieve precise control of the foot movement.

[0045] In some embodiments, please refer to Figure 1 and Figure 8 , which includes an upper hinge (41) fixed to the front sole (21) and a lower hinge (42) fixed to the rear sole plate (22), and the upper hinge (41) and the lower hinge (42) form a revolute pair through a transmission rotating shaft.

[0046] Specifically, the transmission hinge (4) is composed of an upper hinge (41) and a lower hinge (42), wherein the upper hinge (41) is fixed to the front sole (21), and the lower hinge (42) is fixed to the rear sole plate (22). A transmission rotating shaft is provided between the upper hinge (41) and the lower hinge (42), so that when a force is applied to the front sole (21), the upper hinge (41) can be driven to rotate around the lower hinge (42), thereby realizing the predetermined function of the transmission hinge (4). In addition, the design of the transmission hinge enables the front sole to rotate around the lower hinge under the action of a force, that is, to rotate towards the rear sole plate, expanding the range of motion of the foot and improving the flexibility of movement, so as to complete the predetermined motion function. The transmission hinge (4) in the present invention is one implementation manner. In specific applications, those skilled in the art can use different types of hinges to connect the front sole (21) and the rear sole plate (22), such as universal joints (universal hinges), flexible hinges or joint shafts, etc.

[0047] In some embodiments, please refer to Figure 1 , Figure 2 and Figure 9 , the sole elastic element (5) includes a front sole pad (51) and a rear sole plate pad (52); wherein, the front sole pad (51) is fixed to the bottom surface of the front sole (21), and the rear sole plate pad (52) is fixed to the bottom surface of the rear sole plate (22).

[0048] Specifically, the sole elastic element (5) includes a forefoot pad (51) and a rear foot pad (52). The forefoot pad (51) is located under the forefoot (21). Anti-slip patterns can be provided on the surfaces of the forefoot pad (51) and the rear foot pad (52) to enhance the grip. A honeycomb shock-absorbing structure can be adopted inside both of them to improve the buffering effect. In addition, the forefoot pad (51) and the rear foot pad (52) can be made of elastic materials with different hardnesses to provide different levels of comfort and support. Its main function is to provide buffering for walking or exercising, while enhancing the grip, thereby improving comfort and stability. The rear foot pad (52) is located under the rear foot (22), and is designed to provide effective shock-absorbing effect and support for the heel, ensuring the comfort and safety of the user during activities such as walking and jumping.

[0049] Those of ordinary skill in the art can understand that the above-described embodiments are specific examples for implementing the present disclosure, and in practical applications, various changes can be made to them in form and details without departing from the spirit and scope of the present disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure should be determined by the scope defined in the claims.

Claims

1. A foot structure of a robot, characterized in that: The invention comprises a driving mechanism (1), a sole plate (2), an ankle (3), a transmission hinge (4) and a sole elastic element (5); wherein the front sole (21) and the rear sole (22) of the sole plate (2) are hingedly connected via the transmission hinge (4); the ankle (3) is placed on the rear sole (22); the sole elastic element (5) is arranged on the lower surface of the sole plate (2); the driving mechanism (1) is arranged on the upper surface of the sole plate (2), and comprises a motor (13), a transmission push rod (12), a transmission connecting shaft (14), a transmission connecting rod (11) and a driven shaft (15 ); wherein, a motor (13) arranged on the rear foot plate (22) is connected to one end of a transmission push rod (12); the other end of the transmission push rod (12) is connected to the first end of a transmission connecting rod (11) via a transmission connecting shaft (14); the second end of the transmission connecting rod (11) is connected to the front sole (21) via a driven shaft (15); the motor (13) drives the transmission push rod (12) to move, and the transmission push rod (12) drives the front sole (21) to rotate around a transmission hinge (4) via the transmission connecting shaft (14), the transmission connecting rod (11) and the driven shaft (15).

2. The foot structure of the robot according to claim 1, characterized in that: The foot structure comprises at least a plurality of sets of driving mechanisms (1) arranged in parallel, and any set of driving mechanisms (1) is spatially vertically arranged with respect to the transmission hinge (4).

3. The foot structure of the robot according to claim 2, characterized in that: The foot structure comprises two sets of driving mechanisms (1) arranged in parallel, which are respectively arranged on the left and right sides of the foot structure.

4. The foot structure of the robot according to claim 1, characterized in that: A screw rod (131) matched with the motor (13) is provided at one end of the transmission push rod (12); a ball screw is formed between the screw rod (131) and the rotor of the motor (13) via a ball; the motor (13) drives the transmission push rod (12) to move via the ball screw.

5. The foot structure of the robot according to claim 1, characterized in that: The connecting shaft (14) and the driven shaft (15) are respectively embedded in the shaft holes at both ends of the transmission connecting rod (11); the transmission connecting rod (11) and the transmission push rod (12) form a rotation pair through the transmission connecting shaft (14); the transmission connecting rod (11) and the front sole (21) form a rotation pair through the driven shaft (15), so that the motor (13) drives the transmission push rod (12) and drives the front sole (21) to rotate around the transmission hinge (4) through the transmission connecting rod (11).

6. The foot structure of the robot according to claim 4 or 5, characterized in that: The output axis of the motor (13) is colinear with the movement directions of the transmission push rod (12) and the transmission connecting rod (11).

7. The foot structure of the robot according to claim 1, characterized in that: The ankle (3) comprises an ankle boss (31) and a six-dimensional force sensor (32) integrated on the ankle boss (31); wherein: The six-dimensional force sensor (32) is fixed in parallel to the upper surface of the rear foot plate (22); and the ankle boss (31) is connected to the leg of the robot.

8. The foot structure of the robot according to claim 7, characterized in that: The ankle boss (31) is provided with an ankle joint support plate (311), and the ankle joint support plate is provided with an axis hole (312) for fixing the leg connection axis of the robot.

9. The foot structure of the robot according to claim 1, characterized in that: The transmission hinge (4) comprises an upper hinge (41) fixed on the front sole (21) and a lower hinge (42) fixed on the rear foot plate (22), and the upper hinge (41) and the lower hinge (42) form a rotating pair through a transmission shaft.

10. The foot structure of the robot according to claim 1, characterized in that: The sole elastic element (5) comprises a forefoot pad (51) and a rear foot pad (52); wherein the forefoot pad (51) is fixed to the bottom surface of the forefoot (21), and the rear foot pad (52) is fixed to the bottom surface of the rear foot (22).

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