Bionic foot structure, control method thereof and bionic robot

Abstract

The invention discloses a bionic foot structure, a control method of the bionic foot structure and a bionic robot. The bionic foot structure comprises an ankle; the foot plate is rotationally connected with the ankle; a planetary gear structure; the planetary gear structure comprises a gear ring, a planetary gear and a sun gear, the planetary gear and the sun gear are both located in the gear ring, and the planetary gear is meshed with the sun gear and the gear ring. The planetary gear is rotationally connected with the foot plate, and the ankle is connected with the sun gear; the first end of the damping structure is rotationally connected with the foot plate, and the second end of the damping structure is rotationally connected with the gear ring. The foot plate rotates by a large angle relative to the ankle, and the damping structure has small activity; the rotation speed of the foot plate relative to the ankle is high, and the movement speed of the damping structure is low. The matching between the damping structure and the foot plate is improved through the planetary gear structure, so that the bionic foot structure can rotate similar to a human foot.

Description

Technical Field

[0001] The present invention relates to the field of robots, and in particular to a bionic foot structure and a control method thereof, and a bionic robot. Background Art

[0002] The ankle joint is a very important part of a prosthesis. Most prosthetic ankle joints are simple elastic parts such as carbon fiber foot plates. The elastic deformation of the material alone cannot simulate the real ankle force and rotation.

[0003] In the prior art, a damping structure is used to assist the rotation of the prosthetic ankle joint. The damping structure provides passive damping force, but the footsteps are still stiff and the walking gait is still unsmooth, making it difficult to simulate the rotation of the human foot.

[0004] Therefore, the existing technology 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 a bionic foot structure and its control method, and a bionic robot in response to the above-mentioned defects of the prior art, aiming to solve the problem in the prior art that the prosthetic ankle joint is difficult to simulate the rotation of the human foot well.

[0006] The technical solutions adopted by the present invention to solve the technical problems are as follows: A bionic foot structure, comprising: ankle; a foot plate, rotatably connected to the ankle; A planetary gear structure comprising a ring gear, planetary gears, and a sun gear, wherein the planetary gears and the sun gear are both located within the ring gear, and the planetary gears are meshed with the sun gear and the ring gear, respectively; the planetary gears are rotatably connected to the footboard, and the ankle is connected to the sun gear; A damping structure, wherein a first end of the damping structure is rotatably connected to the foot plate, and a second end of the damping structure is rotatably connected to the gear ring.

[0007] The bionic foot structure, wherein the damping structure comprises: A hydraulic cylinder is rotatably connected to the foot plate and the gear ring respectively; The regulator is provided on the hydraulic cylinder and is configured to adjust the flow of the hydraulic oil in the hydraulic cylinder.

[0008] The bionic foot structure, wherein the bionic foot structure further comprises: a drive assembly, disposed on the ankle; Wherein, the ankle is connected to the sun gear through the driving assembly.

[0009] The bionic foot structure, wherein the bionic foot structure further comprises: a motion state sensor configured to detect the motion state of the bionic foot structure; The controller is electrically connected to the motion state sensor, the damping structure, and the driving component respectively.

[0010] The bionic foot structure, wherein the driving assembly includes: a driving member, disposed on the ankle; a worm, arranged on the output shaft of the driving member; The turbine is connected to the sun gear and meshes with the worm.

[0011] The bionic foot structure, wherein the sun gear is formed with a first shaft hole, and the turbine is formed with a second shaft hole; The foot plate is provided with a shaft portion, which passes through the first shaft hole and the second shaft hole in sequence. A connecting piece is provided on the outer surface of the shaft portion, and two ends of the connecting piece are respectively connected to the turbine and the sun gear.

[0012] The bionic foot structure, wherein the foot plate comprises: plate body; a bracket, arranged on the plate body; Wherein, the bracket is provided with the shaft portion.

[0013] A bionic robot, comprising: a bionic foot structure as described in any one of the above items.

[0014] A method for controlling a bionic foot structure as described in any one of the above, comprising the steps of: Based on the motion state sensor, the motion state of the bionic foot structure is obtained; According to the motion state, the driving component and the damping structure are controlled.

[0015] The control method of the bionic foot structure, wherein the motion state includes at least one of a stationary state, a walking state, and a running state; The controlling of the driving component and the controlling of the damping structure according to the motion state includes: According to the static state, controlling the damping structure to increase the damping value and suspending the control of the driving component; According to the walking state, controlling the damping structure to maintain a damping value, and controlling the driving component to maintain a driving frequency; According to the running state, the damping structure is controlled to reduce the damping value, and the driving component is controlled to increase the driving frequency.

[0016] Beneficial effects: The larger the footplate rotates relative to the ankle, the smaller the movement of the damping structure. The faster the footplate rotates relative to the ankle, the smaller the movement of the damping structure. The planetary gear structure improves the matching between the damping structure and the footplate, allowing the bionic foot structure to rotate similarly to a human foot. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a functional principle block diagram of the bionic foot structure in an embodiment of the present invention.

[0018] Figure 2 Schematic diagram of the first structure of the bionic foot structure in an embodiment of the present invention.

[0019] Figure 3 2 is a second structural diagram of the bionic foot structure in an embodiment of the present invention.

[0020] Figure 4 yes Figure 3 A-axis sectional view.

[0021] Figure 5 yes Figure 3 Middle B-direction sectional view.

[0022] Figure 6 1 is an exploded view of the bionic foot structure in an embodiment of the present invention.

[0023] Figure 7 It is a structural schematic diagram of the foot plate, drive assembly, damping structure and planetary gear structure in an embodiment of the present invention.

[0024] Figure 8 3 is a schematic diagram of the third structure of the bionic foot structure in an embodiment of the present invention.

[0025] Figure 9 yes Figure 8 Middle C-section view.

[0026] Figure 10 It is a schematic structural diagram of the bracket, planetary carrier and turbine in an embodiment of the present invention.

[0027] Figure 11 Schematic diagram of the structure of the ankle and the bracket in an embodiment of the present invention.

[0028] Figure 12 Schematic diagram of the structure of the turbine in an embodiment of the present invention.

[0029] Figure 13 2 is a schematic structural diagram of the gear ring seat in an embodiment of the present invention.

[0030] Figure 14 Schematic diagram of the structure of the connecting member in an embodiment of the present invention.

[0031] Figure 152 is a schematic structural diagram of the sun gear in an embodiment of the present invention.

[0032] Description of reference numerals: 10. Ankle; 11. First housing; 111. Limiting portion; 12. Second housing; 121. Notch; 20. Footboard; 21. Board body; 22. Bracket; 221. First vertical board; 222. Second vertical board; 223. Axis; 30. Planetary gear structure; 31. Ring gear; 32. Planetary gear; 33. Sun gear; 331. First shaft hole; 34. Planet carrier; 35. Ring gear seat; 40. Damping structure; 41. Hydraulic cylinder; 42. Regulator; 50. Drive assembly; 51. Drive member; 52. Worm; 53. Turbine; 531. Second shaft hole; 54. Connector. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clear and distinct, 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 intended to limit the present invention.

[0034] Please also see Figures 1-15 , the present invention provides some embodiments of a bionic foot structure.

[0035] like Figure 1 、 Figure 3 、 Figure 4 and Figure 8 As shown, the bionic foot structure of the present invention includes: Ankle 10; A foot plate 20, rotatably connected to the ankle 10; The planetary gear structure 30 includes a ring gear 31, planetary gears 32, and a sun gear 33. The planetary gears 32 and the sun gear 33 are both located within the ring gear 31, and the planetary gears 32 are meshed with the sun gear 33 and the ring gear 31, respectively. The planetary gears 32 are rotatably connected to the foot plate 20, and the ankle 10 is connected to the sun gear 33. The damping structure 40 has a first end rotatably connected to the foot plate 20 , and a second end rotatably connected to the gear ring 31 .

[0036] Specifically, the bionic foot structure mimics the structure of a human foot. The footplate 20 mimics a human footplate, contacts the ground, and supports the bionic foot structure. The ankle 10 mimics a human ankle, enabling rotation of the footplate 20. The damping structure 40 provides resistance to the rotation of the footplate 20, and the planetary gear structure 30 matches the damping structure 40 with the footplate 20. The footplate 20 rotates at a large angle and within a wide range of rotational speeds; the damping structure 40 has a limited range of motion. The planetary gear structure 30 connects the footplate 20 and the damping structure 40, allowing the damping structure 40 to match the rotational angle and speed of the footplate 20. The ring gear 31, planetary gears 32, and sun gear 33 in the planetary gear structure 30 rotate at different speeds and angles. The ring gear 31 rotates at a smaller angle and a lower speed, while the sun gear 33 rotates at a larger angle and a higher speed. The ring gear 31 is rotationally connected to the damping structure 40, the sun gear 33 is connected to the ankle 10, and the planetary gears 32 are rotationally connected to the footplate 20. When the footplate 20 rotates at a greater angle relative to the ankle 10, the damping structure 40 moves less. When the footplate 20 rotates at a higher speed relative to the ankle 10, the damping structure 40 moves less. The planetary gear structure 30 improves the matching between the damping structure 40 and the footplate 20, allowing the bionic foot structure to rotate similarly to a human foot.

[0037] In a preferred implementation of the embodiment of the present invention, Figure 4 and Figure 10 As shown, the planetary gear structure 30 also includes: The planet carrier 34 is provided on the foot plate 20; The planetary gears 32 are rotatably mounted on the planetary carrier 34 .

[0038] Specifically, the planet carrier 34 is fixed to the foot plate 20 , and the planetary gears 32 rotate relative to the planet carrier 34 . The planet carrier 34 is located inside the ring gear 31 .

[0039] In a preferred implementation of the embodiment of the present invention, Figure 3-Figure 6 As shown, the foot plate 20 includes: Plate body 21; The bracket 22 is disposed on the plate body 21 .

[0040] Specifically, the plate 21 contacts the ground, and the bracket 22 is disposed at the rear end of the plate 21. The planet carrier 34 is disposed on the bracket 22. The ankle 10 is rotatably mounted on the bracket 22. The bracket 22 includes two vertical plates: a first vertical plate 221 and a second vertical plate 222. The first vertical plate 221 and the second vertical plate 222 are connected by a shaft 223. The ankle 10 is rotatably mounted on the shaft 223. Specifically, a bearing may be disposed between the shaft 223 and the ankle 10. The planet carrier 34 is disposed on the second vertical plate 222.

[0041] In a preferred implementation of the embodiment of the present invention, Figure 2 、 Figure 3 、 Figure 6 and Figure 11 As shown, the ankle 10 includes a first shell 11 and a second shell 12 connected to each other.

[0042] Specifically, the first housing 11 is positioned between the first upright plate 221 and the second upright plate 222. A notch 121 is formed in the second housing 12, located at a position corresponding to the planetary gear structure 30. The notch 121 provides clearance between the second upright plate 222 and the planetary gear structure 30. A stopper 111 is formed in the first housing 11, which limits the position of the first upright plate 221, restricting the rotation range of the first housing 11 relative to the first upright plate 221. This, in turn, limits the rotation range between the foot plate 20 and the ankle 10.

[0043] In a preferred implementation of the embodiment of the present invention, Figure 5-Figure 7 As shown, the damping structure 40 includes: The hydraulic cylinder 41 is rotatably connected to the foot plate 20 and the gear ring 31 respectively; The regulator 42 is provided on the hydraulic cylinder 41 and is configured to adjust the flow rate of the hydraulic oil in the hydraulic cylinder 41 .

[0044] Specifically, the damping structure 40 can be a damping structure with adjustable damping size. The damping structure 40 can adopt a hydraulic damping structure. For example, there is hydraulic oil and a piston in the cylinder body of the hydraulic cylinder 41, and the piston is connected to a piston rod. The cylinder body is rotatably connected to the foot plate 20, specifically to the middle part of the plate body 21. Figure 4 and Figure 13 As shown, the piston rod is rotatably connected to the ring gear 31. Specifically, the piston rod is connected to the ring gear 31 via the ring gear holder 35, and the piston rod rotates relative to the ring gear holder 35. A bearing is disposed between the ring gear holder 35 and the planetary carrier 34, allowing the ring gear holder 35 to rotate relative to the planetary carrier 34. When the ring gear 31 rotates, it drives the piston rod to extend and retract, causing the piston to move within the cylinder. A regulator 42 adjusts the flow of hydraulic oil in the cylinder, thereby adjusting the resistance experienced by the piston within the cylinder and thereby adjusting the damping effect of the damping structure 40.

[0045] In a preferred implementation of the embodiment of the present invention, Figure 2 、 Figure 3 and Figure 4 As shown, the bionic foot structure further includes: A driving assembly 50 is provided on the ankle 10; The ankle 10 is connected to the sun gear 33 via the driving assembly 50 .

[0046] Specifically, the drive assembly 50 is disposed within the first housing 11 and drives the sun gear 33 to rotate. Because the sun gear 33 rotates simultaneously with the planetary gears 32 and the ring gear 31, and because the ring gear 31 is rotationally connected to the damping structure 40, the rotation of the sun gear 33 is hindered by the damping structure 40. If the damping of the damping structure 40 is high, the sun gear 33 rotates less easily (it can remain stationary relative to the footplate 20). When the drive assembly 50 drives the sun gear 33 to rotate, it can quickly achieve a larger angle of relative rotation between the ankle 10 and the footplate 20. If the damping of the damping structure 40 is low, the sun gear 33 rotates more easily. When the drive assembly 50 drives the sun gear 33 to rotate, it not only causes the sun gear 33 to rotate relative to the footplate 20, thereby extending and retracting the damping structure 40, but also allows the ankle 10 and footplate 20 to rotate more slowly, achieving a smaller angle of relative rotation. By adjusting the damping of the damping structure 40, the ease of relative rotation between the ankle 10 and the footplate 20 can be adjusted.

[0047] In a preferred implementation of the embodiment of the present invention, the bionic foot structure further includes: a motion state sensor configured to detect the motion state of the bionic foot structure; The controller is electrically connected to the motion state sensor, the damping structure 40 and the driving assembly 50 respectively.

[0048] Specifically, the motion state sensor can detect the motion state of the bionic foot structure, and the motion state includes at least one of a stationary state, a walking state, and a running state. The stationary state can be a squatting state, a standing state, a half-squatting state, etc. The walking state can be a slow walk state or a fast walk state. The running state can be a jogging state or a sprint state. The motion state sensor can be an accelerometer, a gyroscope, a magnetometer, an ultrasonic sensor, etc. The motion state sensor can be installed at a position as needed and can be installed on the ankle 10, the foot plate 20, or the planetary gear structure 30. The controller can be arranged in the second housing 12 and electrically connected to the power supply.

[0049] In a preferred implementation of the embodiment of the present invention, Figure 5-Figure 7 As shown, the drive assembly 50 includes: A driving member 51 is provided on the ankle 10; a worm 52 , provided on the output shaft of the driving member 51 ; The turbine 53 is connected to the sun gear 33 and meshes with the worm 52 .

[0050] Specifically, the driving member 51 drives the worm 52 to rotate, which in turn drives the turbine 53 and the sun gear 33. The driving member 51 is disposed within the first housing 11, which covers the driving member 51, the worm 52, and the turbine 53. The bionic foot structure also includes a power supply, which can be disposed within the second housing 12 and provides power to the driving assembly 50 and the motion state sensor.

[0051] In a preferred implementation of the embodiment of the present invention, Figure 9 、 Figure 12 and Figure 15 As shown, a first axial hole 331 is formed on the sun gear 33, and a second axial hole 531 is formed on the turbine 53; a shaft portion 223 is provided on the foot plate 20, and the shaft portion 223 passes through the first axial hole 331 and the second axial hole 531 in sequence, and a connecting member 54 is provided on the outer surface of the shaft portion 223, and the two ends of the connecting member 54 are respectively connected to the turbine 53 and the sun gear 33.

[0052] Specifically, a first shaft hole 331 is formed on the sun gear 33, and a second shaft hole 531 is formed on the turbine 53. The shaft portion 223 is inserted into the first shaft hole 331 and the second shaft hole 531. The shaft portion 223 is provided on the foot plate 20 and can be fixed to the foot plate 20. The sun gear 33 and the turbine 53 both rotate relative to the shaft portion 223. The sun gear 33 and the turbine 53 are connected by a connecting member 54 (see Figure 9 and Figure 14 ), the connecting member 54 can be a shaft sleeve, which is sleeved outside the shaft portion 223, and the sun gear 33, the connecting member 54 and the turbine 53 rotate together. The shaft portion 223 is set on the bracket 22.

[0053] Based on the bionic foot structure described in any one of the above embodiments, the present invention also provides a preferred embodiment of a bionic robot.

[0054] The bionic robot according to the embodiment of the present invention includes the bionic foot structure according to any one of the above embodiments.

[0055] Based on the bionic foot structure described in any one of the above embodiments, the present invention also provides a preferred embodiment of a control method for the bionic foot structure.

[0056] The control method of the bionic foot structure according to the embodiment of the present invention comprises the following steps: Step S100: acquiring the motion state of the bionic foot structure based on the motion state sensor; Step S200: Control the driving component and the damping structure according to the motion state.

[0057] Specifically, the motion state sensor determines the motion state of the bionic foot structure, which includes at least one of a stationary state, a walking state, and a running state. Based on the motion state, the drive assembly and the damping structure are controlled. Specifically, the drive assembly is controlled to achieve rotation of the ankle and foot, and the damping value of the damping structure is controlled to adjust the ease of rotation between the ankle and foot.

[0058] Step S200 specifically includes: Step S210: According to the static state, controlling the damping structure to increase the damping value and suspending control of the driving component; Step S220: controlling the damping structure to maintain a damping value and controlling the driving component to maintain a driving frequency according to the walking state; Step S230: According to the running state, the damping structure is controlled to reduce the damping value, and the driving component is controlled to increase the driving frequency.

[0059] Specifically, in the initial state, the damping value of the damping structure is configured according to the walking state, and the driving frequency of the active component is also configured according to the walking state, so as to facilitate the user's walking. The driving frequency refers to the frequency at which the footplate is driven to rotate back and forth relative to the ankle. When the bionic foot structure is in the walking state, the damping structure is controlled to maintain the damping value, and the driving component is controlled to drive the footplate to rotate relative to the ankle at the driving frequency to assist the user in walking. When the bionic foot structure is in a stationary state, it is necessary to control the damping structure to increase the damping value and suspend control of the driving component. Due to the large damping value of the damping structure, the ring gear, planetary gears and sun gear are not easy to rotate, and the turbine and worm are also not easy to rotate, and the footplate and ankle are also not easy to rotate. When the bionic foot structure is in the running state, it is necessary to control the damping structure to reduce the damping value and control the driving component to increase the driving frequency to adapt to the frequency at which the user's footplate rotates back and forth when running.

[0060] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, 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. A bionic foot structure, characterized in that: include: ankle; a foot plate, rotatably connected to the ankle; Planetary gear structure; The planetary gear structure includes: a ring gear, planetary gears and a sun gear, wherein the planetary gears and the sun gear are both located within the ring gear, and the planetary gears are meshed with the sun gear and the ring gear respectively; the planetary gears are rotatably connected to the footboard, and the ankle is connected to the sun gear; A damping structure, wherein a first end of the damping structure is rotatably connected to the foot plate, and a second end of the damping structure is rotatably connected to the gear ring.

2. The bionic foot structure according to claim 1, characterized in that: The damping structure comprises: A hydraulic cylinder is rotatably connected to the foot plate and the gear ring respectively; The regulator is provided on the hydraulic cylinder and is configured to adjust the flow of the hydraulic oil in the hydraulic cylinder.

3. The bionic foot structure according to any one of claims 1 to 2, characterized in that: The bionic foot structure further comprises: a drive assembly, disposed on the ankle; Wherein, the ankle is connected to the sun gear through the driving assembly.

4. The bionic foot structure according to claim 3, characterized in that: The bionic foot structure further comprises: a motion state sensor configured to detect the motion state of the bionic foot structure; The controller is electrically connected to the motion state sensor, the damping structure, and the driving component respectively.

5. The bionic foot structure according to claim 4, characterized in that: The drive assembly includes: a driving member, disposed on the ankle; a worm, arranged on the output shaft of the driving member; The turbine is connected to the sun gear and meshes with the worm.

6. The bionic foot structure according to claim 5, characterized in that: A first shaft hole is formed on the sun gear, and a second shaft hole is formed on the turbine; The foot plate is provided with a shaft portion, which passes through the first shaft hole and the second shaft hole in sequence. A connecting piece is provided on the outer surface of the shaft portion, and two ends of the connecting piece are respectively connected to the turbine and the sun gear.

7. The bionic foot structure according to claim 6, characterized in that: The footboard includes: plate body; a bracket, arranged on the plate body; Wherein, the bracket is provided with the shaft portion.

8. A bionic robot, characterized in that: include: The bionic foot structure according to any one of claims 1 to 7.

9. A method for controlling a bionic foot structure according to any one of claims 4 to 7, characterized in that: Including steps: Based on the motion state sensor, the motion state of the bionic foot structure is obtained; According to the motion state, the driving component and the damping structure are controlled.

10. The control method of the bionic foot structure according to claim 9, characterized in that: The motion state includes at least one of a stationary state, a walking state, and a running state; The controlling of the driving component and the controlling of the damping structure according to the motion state includes: According to the static state, controlling the damping structure to increase the damping value and suspending the control of the driving component; According to the walking state, controlling the damping structure to maintain a damping value, and controlling the driving component to maintain a driving frequency; According to the running state, the damping structure is controlled to reduce the damping value, and the driving component is controlled to increase the driving frequency.

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