Ankle joint and control method thereof, artificial leg and robot

Abstract

The invention discloses an ankle joint and a control method thereof, an artificial leg and a robot. The ankle joint comprises a foot connecting structure; the leg connecting structure is rotationally connected with the foot connecting structure; the driving mechanism is arranged on the leg connecting structure and is connected with the foot connecting structure; the homing mechanism is connected with the driving mechanism; the driving mechanism is configured to drive the foot connecting structure to rotate in the front-back direction of the foot relative to the leg connecting structure; the homing mechanism is configured to return the foot connection structure to an initial position. In the walking process, the real feet rotate back and forth to present different postures. The foot connecting structure is driven by the driving mechanism to rotate front and back, the foot presents different postures in combination with the returning effect of the returning mechanism, the ankle joint is closer to the ankle joint of a real foot, and the bionic effect of the ankle joint and the foot is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of robots, and in particular to an ankle joint and a control method thereof, a prosthetic leg and a robot. Background Art

[0002] In the field of prosthetics or robotics, joints are important components for displaying various postures. The movement of the ankle joint plays an indispensable role in every gait cycle of human walking, and also plays a very important role in various postures of human walking, such as running.

[0003] The existing technology mainly focuses on the knee joint and ignores the ankle joint. The calf and foot are usually rigidly connected, which makes the bionic effect of the ankle joint poor.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an ankle joint and a control method thereof, a prosthetic leg and a robot in view of the above-mentioned defects of the prior art, aiming to solve the problem of poor bionic effect of the ankle joint in the prior art.

[0006] The technical solution adopted by the present invention to solve the technical problem is as follows: An ankle joint, comprising: Foot connection structure; A leg connection structure, rotatably connected to the foot connection structure; A driving mechanism, disposed on the leg connection structure and connected to the foot connection structure; A homing mechanism connected to the driving mechanism; wherein the driving mechanism is configured to drive the foot connection structure to rotate relative to the leg connection structure along the front-rear direction of the foot; The return mechanism is configured to return the foot connection structure to an initial position.

[0007] The ankle joint, wherein the ankle joint further comprises: A motion sensor is disposed on the leg connection structure; Wherein, the motion sensor is configured to detect the motion state of the leg connection structure.

[0008] The ankle joint, wherein the driving mechanism comprises: A first driving member, disposed on the leg connection structure; a first connecting rod connected to the output shaft of the first driving member; a second connecting rod, rotatably connected to the first connecting rod; a third connecting rod, rotatably connected to the second connecting rod; Wherein, the third connecting rod is connected to the foot connecting structure and rotates relative to the leg connecting structure.

[0009] The ankle joint, wherein the homing mechanism comprises: a first elastic structure, connected to the leg connection structure and the first connecting rod respectively; Wherein, the first elastic structure provides elastic force for returning the first connecting rod.

[0010] The ankle joint, wherein the foot connection structure comprises: a first connection structure, rotatably connected to the leg connection structure; a second connecting structure, rotatably connected to the first connecting structure; a second elastic structure, connecting the first connection structure and the second connection structure respectively; wherein the first connection structure rotates relative to the leg connection structure along the front-rear direction of the foot; The second connection structure rotates relative to the first connection structure along the left-right direction of the foot.

[0011] The ankle joint, wherein the ankle joint further comprises: The damping mechanism is rotatably arranged on the leg connection structure and connected to the foot connection structure.

[0012] The ankle joint, wherein the damping mechanism comprises: a fourth connecting rod, rotatably connected to the foot connecting structure; a fifth connecting rod, rotatably connected to the fourth connecting rod and the leg connecting structure respectively; a damping structure, rotatably disposed on the leg connection structure and rotatably connected to the fifth connecting rod; An adjusting structure, rotatably disposed on the leg connecting structure and connected to the damping structure; Wherein, the adjustment structure is configured to adjust the damping of the damping structure.

[0013] An artificial leg, comprising the ankle joint as described in any one of the above items.

[0014] A robot, wherein it comprises an ankle joint as described in any one of the above, or a prosthetic leg as described above.

[0015] A method for controlling an ankle joint as described in any one of the above, comprising the steps of: Based on the motion sensor, determining the motion state of the leg connection structure; the motion state includes: a forward motion state and a stable state; According to the forward movement state of the leg connection structure, the foot connection structure is controlled by the driving mechanism to rotate forward, and after the leg connection structure becomes a stable state, the foot connection structure is controlled by the driving mechanism to rotate backward.

[0016] The ankle joint control method, wherein the motion state further includes: a backward motion state; the control method further includes: According to the backward movement state of the leg connection structure, the foot connection structure is controlled by the driving mechanism to rotate backward, and after the leg connection structure becomes a stable state, the foot connection structure is controlled by the driving mechanism to rotate forward.

[0017] The ankle joint control method, wherein the control method further comprises: According to the movement state of the leg connection structure, the damping of the damping structure is controlled by adjusting the structure.

[0018] Beneficial effect: During walking, the real foot rotates forward and backward to present different postures. The present invention drives the foot connection structure to rotate forward and backward through a driving mechanism, and combines the return effect of the homing mechanism to make the foot present different postures. The ankle joint of the present invention is closer to the ankle joint of a real foot, thereby improving the bionic effect of the ankle joint and the foot. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 1 is a first structural schematic diagram of the ankle joint and foot plate structure in an embodiment of the present invention.

[0020] Figure 2 2 is a second structural schematic diagram of the ankle joint and foot plate structure in an embodiment of the present invention.

[0021] Figure 3 yes Figure 2 Magnified view of the mid-ankle joint.

[0022] Figure 4 1 is a first structural schematic diagram of a driving mechanism and a foot connection structure in an embodiment of the present invention.

[0023] Figure 5 1 is a second structural schematic diagram of the driving mechanism and the foot connection structure in an embodiment of the present invention.

[0024] Figure 6 1 is a side view of the ankle joint and foot plate structure in an embodiment of the present invention.

[0025] Figure 7 is a cross-sectional view of an ankle joint in an embodiment of the present invention.

[0026] Figure 8 1 is a third structural schematic diagram of the ankle joint and foot plate structure in an embodiment of the present invention.

[0027] Fig. 9 2 is a cross-sectional view of an ankle joint in an embodiment of the present invention.

[0028] Fig.10 It is a first structural schematic diagram of the damping mechanism and the foot connection structure in an embodiment of the present invention.

[0029] Fig.11 1 is a second structural schematic diagram of the damping mechanism and the foot connection structure in an embodiment of the present invention.

[0030] Fig.12 Schematic diagram of the structure of the foot plate in an embodiment of the present invention.

[0031] Fig.13 It is a schematic diagram of the foot plate structure in the tiptoe state according to the embodiment of the present invention.

[0032] Fig.14 Schematic diagram of the foot structure in the tiptoe position according to the embodiment of the present invention.

[0033] Description of reference numerals: 10. Foot connection structure; 11. First connection structure; 12. Second connection structure; 13. Second elastic structure; 20. Leg connection structure; 30. Driving mechanism; 31. First driving member; 32. First connecting rod; 33. Second connecting rod; 34. Third connecting rod; 40. Return mechanism; 51. Motion sensor; 52. Controller; 60. Damping mechanism; 61. Fourth connecting rod; 62. Fifth connecting rod; 63. Damping structure; 64. Adjusting structure; 641. Second driving member; 642. Driving gear; 643. Driven gear; 70. Foot structure; 71. Back; 72. Palm; 73. Heel. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] Please also see Figure 1-Figure 14 , the present invention provides some embodiments of an ankle joint.

[0036] like Figure 1-Figure 2 As shown, the ankle joint of the present invention comprises: Foot connection structure 10; A leg connection structure 20, rotatably connected to the foot connection structure 10; A driving mechanism 30, disposed on the leg connection structure 20 and connected to the foot connection structure 10; A homing mechanism 40 connected to the driving mechanism 30; Wherein, the driving mechanism 30 is configured to drive the foot connection structure 10 to rotate relative to the leg connection structure 20 along the front-rear direction of the foot; The return mechanism 40 is configured to return the foot connection structure 10 to an initial position.

[0037] Specifically, the foot connection structure 10 is used to connect the foot plate structure 70, and the leg connection structure 20 is used to connect the leg structure. The foot connection structure 10 and the leg connection structure 20 rotate relative to each other, thereby changing the posture of the overall structure. The driving mechanism 30 is used to drive the foot connection structure 10 to rotate relative to the leg connection structure 20, and the specific rotation direction is the front and back direction of the foot. The return mechanism 40 is used to rotate the foot connection structure 10 relative to the leg connection structure 20 and return it to the initial position. The initial position is the position where the central axis of the foot connection structure 10 coincides with the central axis of the leg connection structure, and the foot plate structure 70 and the leg structure are approximately in a vertical state.

[0038] When the foot plate structure 70 is in a natural state, the foot connection structure 10 is in an initial position, and the central axis of the foot connection structure 10 coincides with the central axis of the leg connection structure. Fig.13 As shown, when the driving mechanism 30 drives the foot connection structure 10 to rotate toward the front of the foot, the foot plate structure 70 is in a toe-tip state; Fig.14 As shown, when the driving structure drives the foot connection structure 10 to rotate toward the rear of the foot, the foot plate structure 70 is in a tiptoe state. Regardless of whether the foot plate structure 70 is in a tiptoe state or a tiptoe state, after the driving mechanism 30 stops driving, the return mechanism 40 will return the foot connection structure 10 to its initial position, so that the foot connection structure 10 is in a natural state.

[0039] When walking, when the first real foot steps forward, the first real foot is in a state of tiptoeing. After the first real foot touches the ground, the first real foot gradually returns to a natural state. When the second real foot steps forward, the first real foot gradually changes from a natural state to a state of tiptoeing. After the first real foot leaves the ground, the first real foot gradually returns to a natural state. It can be seen that during walking, the real foot rotates back and forth to present different postures. The present application drives the foot connection structure 10 to rotate back and forth through the driving mechanism 30, and combines the return effect of the homing mechanism 40 to make the foot present different postures. The ankle joint of the present application is closer to the ankle joint of the real foot, thereby improving the bionic effect of the ankle joint and the foot.

[0040] In a preferred implementation of the embodiment of the present invention, Figure 1-Figure 2 As shown, the ankle joint also includes: A motion sensor 51, disposed on the leg connection structure 20; The motion sensor 51 is configured to detect the motion state of the leg connection structure 20 .

[0041] Specifically, the leg connection structure 20 is also equipped with a motion sensor 51, which detects the motion state of the leg connection structure 20, and the motion state includes at least one of a forward motion state, a backward motion state, and a stable state. When the leg connection structure 20 leaves the ground and steps forward, it is in a forward motion state; when the leg connection structure 20 leaves the ground and steps backward, it is in a backward motion state; when the leg connection structure 20 contacts the ground, it is in a stable state. The motion state of the foot connection structure 10 can be determined by the motion sensor 51, so that the drive mechanism 30 is controlled according to the motion state to drive the foot connection structure 10 to rotate forward and backward.

[0042] The ankle joint further includes a controller 52 which is electrically connected to the driving mechanism 30 and the motion sensor 51 . The controller 52 obtains the motion state sensed by the motion sensor 51 and controls the driving mechanism 30 .

[0043] In a preferred implementation of the embodiment of the present invention, Figure 3-Figure 6 As shown, the driving mechanism 30 includes: A first driving member 31, disposed on the leg connecting structure 20; A first connecting rod 32 connected to the output shaft of the first driving member 31; A second connecting rod 33, rotatably connected to the first connecting rod 32; A third connecting rod 34, rotatably connected to the second connecting rod 33; The third connecting rod 34 is connected to the foot connecting structure 10 and rotates relative to the leg connecting structure 20 .

[0044] Specifically, the first driving member 31 drives the first connecting rod 32 to rotate, and drives the second connecting rod 33 and the third connecting rod 34 to rotate, thereby driving the foot connecting structure 10 to rotate relative to the leg connecting structure 20 through the third connecting rod 34. The leg connecting structure 20 is provided with two ring structures, and the ring structures are sleeved outside the third connecting rod 34.

[0045] In a preferred implementation of the embodiment of the present invention, Figure 3-Figure 5 As shown, the homing mechanism 40 includes: A first elastic structure is connected to the leg connection structure 20 and the first connecting rod 32 respectively; The first elastic structure provides elastic force for returning the first connecting rod 32 .

[0046] Specifically, the return mechanism 40 adopts a first elastic structure, and the first elastic structure is connected to the leg connection structure 20 and the first connecting rod 32 respectively. When the foot connection structure 10 is in the initial position relative to the leg connection structure 20, the first elastic structure is in a natural state; if the first driving member 31 drives the first connecting rod 32 to rotate, the first elastic structure is deformed, and the elastic force provided by the first elastic structure causes the first connecting rod 32 to return to the natural state. The first elastic structure can adopt a torsion spring, and the torsion spring provides elastic force when the first connecting rod 32 rotates clockwise or counterclockwise.

[0047] In a preferred implementation of the embodiment of the present invention, Figure 1-Figure 4 As shown, the foot connection structure 10 includes: A first connection structure 11, rotatably connected to the leg connection structure 20; A second connecting structure 12, rotatably connected to the first connecting structure 11; A second elastic structure 13, connected to the first connection structure 11 and the second connection structure 12 respectively; The first connection structure 11 rotates along the front-to-back direction of the foot relative to the leg connection structure 20 ; the second connection structure 12 rotates along the left-to-right direction of the foot relative to the first connection structure 11 .

[0048] Specifically, the foot connection structure 10 is divided into two parts, namely, a first connection structure 11 and a second connection structure 12, the first connection structure 11 and the second connection structure 12 are rotatably connected to each other, and the first connection structure 11 and the leg connection structure 20 are rotatably connected to each other. A second elastic structure 13 is arranged between the first connection structure 11 and the second connection structure 12, and the second elastic structure 13 provides an elastic force for the first connection structure 11 to return relative to the second connection structure 12. The first connection structure 11 rotates in the left-right direction of the foot relative to the second connection structure 12, and the first connection structure 11 rotates in the front-back direction of the foot relative to the leg connection structure 20. Through the elastic force provided by the first elastic structure and the second elastic structure 13, the foot plate structure 70 moves within a certain angle range relative to the leg structure.

[0049] The first connecting structure 11 and the second connecting structure 12 are rotatably connected to each other at a location where the first connecting structure 11 and the second connecting structure 12 are rotatably connected to each other, and there are two groups of second elastic structures 13, which are respectively located on both sides of the rotational center axis. The left rotation of the first connecting structure 11 relative to the second connecting structure 12 will force one group of the second elastic structures 13 to deform, and the right rotation of the first connecting structure 11 relative to the second connecting structure 12 will force the other group of the second elastic structures 13 to deform.

[0050] In a preferred implementation of the embodiment of the present invention, Figure 7-Figure 11 As shown, the ankle joint also includes: The damping mechanism 60 is rotatably arranged on the leg connection structure 20 and connected to the foot connection structure 10.

[0051] Specifically, the elastic coefficient of the first elastic structure is smaller than that of the second elastic structure 13. The foot plate structure 70 is not easily rotated left and right, but is more easily rotated back and forth. The damping mechanism 60 is configured to provide resistance to the back-and-forth rotation of the foot plate structure 70, and hinder the rotation of the foot connection structure 10 relative to the leg connection structure 20 in the front-back direction of the foot.

[0052] In a preferred implementation manner of the embodiment of the present invention, as Figure 9-11 shown, the damping mechanism 60 includes: A fourth connecting rod 61, rotatably connected to the foot connection structure 10; A fifth connecting rod 62, respectively rotatably connected to the fourth connecting rod 61 and the leg connection structure 20; A damping structure 63, rotatably arranged on the leg connection structure 20 and rotatably connected to the fifth connecting rod 62; An adjusting structure 64, rotatably arranged on the leg connection structure 20 and connected to the damping structure 63; Wherein, the adjusting structure 64 is configured to adjust the damping of the damping structure 63.

[0053] Specifically, the damping mechanism 60 is a mechanism with adjustable damping, and specifically adjusts the damping of the damping structure 63 through the adjusting structure 64. When the foot connection structure 10 and the leg connection structure 20 rotate relative to each other, the foot connection structure 10 drives the fourth connecting rod 61 and the fifth connecting rod 62 to rotate, thereby driving the damping structure 63 to expand and contract, and providing a resistance to hinder the relative rotation of the foot connection structure 10 and the leg connection structure 20.

[0054] In a preferred implementation manner of the embodiment of the present invention, as Figure 9-10 shown, the adjusting structure 64 includes: A second driving member 641, rotatably arranged on the leg connection structure 20; A driving gear 642, arranged on the output shaft of the second driving member 641; A driven gear 643, arranged on the damping structure 63 and meshing with the driving gear 642.

[0055] Specifically, the second driving member 641 is driven to rotate the driving gear 642, and drives the driven gear 643 to rotate, thereby rotating the knob of the damping structure 63 to adjust the damping of the damping structure 63.

[0056] Based on the ankle joint described in any of the above embodiments, the present invention also provides a preferred embodiment of a control method for an ankle joint.

[0057] The ankle joint control method of the embodiment of the present invention comprises the following steps: Step S100: determining the motion state of the leg connection structure based on the motion sensor; the motion state includes: at least one of a forward motion state, a backward motion state, and a stable state; Step S200: According to the forward movement state of the leg connection structure, the foot connection structure is controlled to rotate forward by the driving mechanism, and after the leg connection structure becomes a stable state, the foot connection structure is controlled to rotate backward by the driving mechanism.

[0058] Specifically, the motion state can be divided into a forward motion state with a large acceleration, a backward motion state with a large acceleration, and a stable state with a small acceleration according to the magnitude of the acceleration. The forward motion state with a large acceleration can also be divided into a walking state with a large acceleration and a running state with an even larger acceleration.

[0059] The foot can walk forward, and the ankle joint needs to rotate the foot connection structure forward after the foot plate structure leaves the ground, so that the foot plate structure is in a tiptoe state, which is convenient for the heel to touch the ground. After the foot plate structure touches the ground, the foot connection structure is slowly rotated backward, so that the foot plate structure is in a tiptoe state, which is convenient for the toe to touch the ground.

[0060] The control method also includes: Step S300: According to the backward movement state of the leg connection structure, the foot connection structure is controlled to rotate backward by the driving mechanism, and after the leg connection structure becomes a stable state, the foot connection structure is controlled to rotate forward by the driving mechanism.

[0061] Specifically, the foot can also walk backwards, and the ankle joint needs to rotate the foot connection structure backwards after the foot plate structure leaves the ground, so that the foot plate structure is in a tiptoe state, which is convenient for the toes to touch the ground later. After the foot plate structure touches the ground, the foot connection structure is slowly rotated forward, so that the foot plate structure is in a tiptoe state, which is convenient for the toes to leave the ground.

[0062] The control method also includes: Step S400: According to the motion state of the leg connection structure, the damping of the damping structure is controlled by adjusting the structure.

[0063] Specifically, the damping of the damping structure can be adjusted according to the state of motion. In the walking state, the damping structure adopts a smaller damping, which is convenient for controlling the forward or backward rotation of the foot connection structure through the first driving member; in the running state, the damping structure adopts a larger damping, which is convenient for buffering the impact of the body on the ankle joint, so that the foot plate structure is more stable when running and is not easy to fall.

[0064] Based on the ankle joint described in any one of the above embodiments, the present invention also provides an embodiment of a prosthetic leg.

[0065] like Figure 1 and Figure 2 As shown, the artificial leg of the present invention comprises: an ankle joint as in any of the above-mentioned embodiments. The artificial leg also comprises a foot plate structure 70 and a leg structure. The foot connection structure 10 is connected to the foot plate structure 70, and the leg structure is connected to the leg connection structure 20. Fig.12 As shown, the foot plate structure 70 includes: A back portion 71 connected to the foot connection structure 10; A palm portion 72 connected to the back portion 71; a heel portion 73 connected to the back portion 71; The palm portion 72 and the heel portion 73 are spaced apart from each other.

[0066] Specifically, the back 71 is connected to the second connection structure 12. The back 71 has a certain strength and can be deformed. When walking or running, the palm 72 touches the ground and the heel 73 leaves the ground, the back 71 bends, and the distance between the palm 72 and the heel 73 increases. With the support of the palm 72, the foot is more stable.

[0067] Based on the ankle joint described in any of the above embodiments, the present invention also provides an embodiment of a robot.

[0068] The robot of the present invention comprises: an ankle joint as in any one of the above embodiments or a prosthetic leg as in any one of the above embodiments.

[0069] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. An ankle joint, characterized in that: include: Foot connection structure; A leg connection structure, rotatably connected to the foot connection structure; A driving mechanism, disposed on the leg connection structure and connected to the foot connection structure; A homing mechanism connected to the driving mechanism; wherein the driving mechanism is configured to drive the foot connection structure to rotate relative to the leg connection structure along the front-rear direction of the foot; The return mechanism is configured to return the foot connection structure to an initial position.

2. The ankle joint according to claim 1, characterized in that: The ankle joint also includes: A motion sensor is disposed on the leg connection structure; Wherein, the motion sensor is configured to detect the motion state of the leg connection structure.

3. The ankle joint according to claim 2, characterized in that: The driving mechanism comprises: A first driving member, disposed on the leg connection structure; a first connecting rod connected to the output shaft of the first driving member; a second connecting rod, rotatably connected to the first connecting rod; a third connecting rod, rotatably connected to the second connecting rod; Wherein, the third connecting rod is connected to the foot connecting structure and rotates relative to the leg connecting structure.

4. The ankle joint according to claim 3, characterized in that: The homing mechanism comprises: a first elastic structure, connected to the leg connection structure and the first connecting rod respectively; Wherein, the first elastic structure provides elastic force for returning the first connecting rod.

5. The ankle joint according to claim 2, characterized in that: The foot connection structure comprises: a first connection structure, rotatably connected to the leg connection structure; a second connecting structure, rotatably connected to the first connecting structure; a second elastic structure, connecting the first connection structure and the second connection structure respectively; wherein the first connection structure rotates relative to the leg connection structure along the front-rear direction of the foot; The second connection structure rotates relative to the first connection structure along the left-right direction of the foot.

6. The ankle joint according to claim 2, characterized in that: The ankle joint also includes: The damping mechanism is rotatably arranged on the leg connection structure and connected to the foot connection structure.

7. The ankle joint according to claim 6, characterized in that: The damping mechanism comprises: a fourth connecting rod, rotatably connected to the foot connecting structure; a fifth connecting rod, rotatably connected to the fourth connecting rod and the leg connecting structure respectively; a damping structure, rotatably disposed on the leg connection structure and rotatably connected to the fifth connecting rod; An adjusting structure, rotatably disposed on the leg connecting structure and connected to the damping structure; Wherein, the adjustment structure is configured to adjust the damping of the damping structure.

8. A prosthetic leg, characterized in that: It comprises the ankle joint as claimed in any one of claims 1 to 7.

9. A robot, characterized in that: It comprises an ankle joint as claimed in any one of claims 1 to 7, or a prosthetic leg as claimed in claim 8.

10. A method for controlling an ankle joint according to any one of claims 2 to 7, characterized in that: Includes steps: Based on the motion sensor, determining the motion state of the leg connection structure; the motion state includes: a forward motion state and a stable state; According to the forward movement state of the leg connection structure, the foot connection structure is controlled by the driving mechanism to rotate forward, and after the leg connection structure becomes a stable state, the foot connection structure is controlled by the driving mechanism to rotate backward.

11. The ankle joint control method according to claim 10, characterized in that: The motion state also includes: a backward motion state; the control method also includes: According to the backward movement state of the leg connection structure, the foot connection structure is controlled by the driving mechanism to rotate backward, and after the leg connection structure becomes a stable state, the foot connection structure is controlled by the driving mechanism to rotate forward.

12. The ankle joint control method according to claim 10, characterized in that: The control method further comprises: According to the movement state of the leg connection structure, the damping of the damping structure is controlled by adjusting the structure.

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