A biomimetic foot structure and its control method, and a biomimetic robot

Abstract

This invention discloses a bionic foot structure and its control method, as well as a bionic robot. The bionic foot structure includes: an ankle; a foot plate rotatably connected to the ankle; a planetary gear structure; the planetary gear structure includes: a gear ring, planetary gears, and a sun gear, with the planetary gears and the sun gear both located within the gear ring, and the planetary gears meshing with the sun gear and the gear ring respectively; the planetary gears are rotatably connected to the foot plate, and the ankle is connected to the sun gear; a damping structure, with a first end rotatably connected to the foot plate and a second end rotatably connected to the gear ring. When the foot plate rotates at a large angle relative to the ankle, the damping structure has a small range of motion; when the foot plate rotates at a high speed relative to the ankle, the damping structure has a low range of motion. By using a planetary gear structure to improve the matching between the damping structure and the foot plate, the bionic foot structure exhibits rotation similar to that of a human foot.

Description

Technical Field

[0001] This invention relates to the field of robotics, and more particularly to a biomimetic foot structure and its control method, and a biomimetic robot. Background Technology

[0002] The ankle joint is a very important part of a prosthesis. Most prosthetic ankle joints are simple elastic components, such as carbon fiber footplates. Simply relying on the elastic deformation of the material cannot simulate the force and rotation of the real ankle.

[0003] In existing technologies, the ankle joint rotation of a prosthesis is assisted by a damping structure. The damping structure provides passive damping force, but the foot movement is still stiff and the walking gait is still not free, making it difficult to simulate the rotation of the human foot well.

[0004] Therefore, existing technologies still need 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, as well as a bionic robot, in order to address the above-mentioned deficiencies of the prior art, and to solve the problem that the ankle joint of the prosthetic limb in the prior art is difficult to simulate the rotation of the human foot well.

[0006] The technical solution adopted by this invention to solve the technical problem is as follows:

[0007] A biomimetic foot structure, comprising:

[0008] ankle;

[0009] The footplate is rotatably connected to the ankle.

[0010] A 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 mesh with the sun gear and the ring gear respectively; the planetary gears are rotatably connected to the footplate, and the ankle is connected to the sun gear;

[0011] A damping structure, wherein the first end of the damping structure is rotatably connected to the foot plate, and the second end of the damping structure is rotatably connected to the gear ring.

[0012] The biomimetic foot structure, wherein the damping structure includes:

[0013] Hydraulic cylinders are rotatably connected to the foot plate and the gear ring, respectively.

[0014] A regulator is disposed in the hydraulic cylinder and configured to regulate the flow rate of hydraulic oil in the hydraulic cylinder.

[0015] The bionic foot structure further includes:

[0016] A drive component is located on the ankle;

[0017] The ankle is connected to the sun gear via the drive assembly.

[0018] The bionic foot structure further includes:

[0019] A motion state sensor is configured to detect the motion state of the bionic foot structure;

[0020] The controller is electrically connected to the motion state sensor, the damping structure, and the drive assembly, respectively.

[0021] The bionic foot structure, wherein the driving component includes:

[0022] A drive unit is located at the ankle;

[0023] A worm gear is disposed on the output shaft of the drive component;

[0024] The turbine is connected to the sun gear and meshes with the worm gear.

[0025] In the aforementioned bionic foot structure, a first shaft hole is formed on the sun gear, and a second shaft hole is formed on the turbine.

[0026] 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 member is sleeved on the shaft portion, and the two ends of the connecting member are respectively connected to the turbine and the sun gear.

[0027] The aforementioned bionic foot structure, wherein the foot plate comprises:

[0028] plate body;

[0029] A bracket is provided on the plate.

[0030] The bracket is provided with the shaft portion.

[0031] A biomimetic robot, comprising: a biomimetic foot structure as described in any of the above.

[0032] A method for controlling a bionic foot structure as described in any of the above claims, comprising the steps of:

[0033] Based on motion state sensors, the motion state of the bionic foot structure is acquired;

[0034] Based on the motion state, control the drive components and control the damping structure.

[0035] The control method for the bionic foot structure, wherein the movement state includes at least one of the following: a stationary state, a walking state, and a running state;

[0036] The step of controlling the drive component and the damping structure according to the motion state includes:

[0037] Based on the static state, the damping structure is controlled to increase the damping value, and the control drive component is paused;

[0038] Based on the walking state, the damping structure is controlled to maintain the damping value, and the drive components are controlled to maintain the drive frequency.

[0039] Based on the running state, the damping structure is controlled to decrease the damping value, and the drive component is controlled to increase the drive frequency.

[0040] Beneficial effects: The foot plate rotates at a large angle relative to the ankle, while the damping structure has a small range of motion; the foot plate rotates at a high speed relative to the ankle, while the damping structure has a low speed of motion. By using a planetary gear structure to improve the matching between the damping structure and the foot plate, the bionic foot structure can achieve rotation similar to that of a human foot. Attached Figure Description

[0041] Figure 1 This is a functional principle block diagram of the bionic foot structure in an embodiment of the present invention.

[0042] Figure 2 This is a first structural schematic diagram of the bionic foot structure in an embodiment of the present invention.

[0043] Figure 3 This is a schematic diagram of the second structure of the bionic foot structure in an embodiment of the present invention.

[0044] Figure 4 yes Figure 3 Sectional view along line A.

[0045] Figure 5 yes Figure 3 Sectional view along line B.

[0046] Figure 6 This is an exploded view of the bionic foot structure in an embodiment of the present invention.

[0047] Figure 7 This is a schematic diagram of the foot plate, drive assembly, damping structure and star gear structure in an embodiment of the present invention.

[0048] Figure 8 This is a schematic diagram of the third structure of the bionic foot structure in this embodiment of the invention.

[0049] Figure 9 yes Figure 8 Sectional view along line C.

[0050] Figure 10 This is a schematic diagram of the structure of the support, planetary carrier, and turbine in an embodiment of the present invention.

[0051] Figure 11 This is a schematic diagram of the ankle and support structure in an embodiment of the present invention.

[0052] Figure 12 This is a schematic diagram of the turbine structure in an embodiment of the present invention.

[0053] Figure 13 This is a schematic diagram of the gear ring seat in an embodiment of the present invention.

[0054] Figure 14 This is a schematic diagram of the connector structure in an embodiment of the present invention.

[0055] Figure 15 This is a schematic diagram of the sun gear in an embodiment of the present invention.

[0056] Explanation of reference numerals in the attached figures:

[0057] 10. Ankle; 11. First shell; 111. Limiting part; 12. Second shell; 121. Notch;

[0058] 20. Foot plate; 21. Plate body; 22. Support; 221. First upright plate; 222. Second upright plate; 223. Shaft;

[0059] 30. Planetary gear structure; 31. Gear ring; 32. Planetary gear; 33. Sun gear; 331. First shaft hole; 34. Planet carrier; 35. Gear ring seat;

[0060] 40. Damping structure; 41. Hydraulic cylinder; 42. Regulator;

[0061] 50. Drive assembly; 51. Drive component; 52. Worm gear; 53. Turbine; 531. Second shaft hole; 54. Connecting component. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0063] Please also refer to Figures 1-15 This invention provides some embodiments of a biomimetic foot structure.

[0064] like Figure 1 , Figure 3 , Figure 4 and Figure 8 As shown, the bionic foot structure of the present invention includes:

[0065] Ankle 10;

[0066] Foot plate 20 is rotatably connected to ankle 10;

[0067] Planetary gear structure 30; the planetary gear structure 30 includes: a gear ring 31, planetary gears 32 and a sun gear 33, the planetary gears 32 and the sun gear 33 are both located inside the gear ring 31, and the planetary gear 32 meshes with the sun gear 33 and the gear ring 31 respectively; the planetary gear 32 is rotatably connected to the foot plate 20, and the ankle 10 is connected to the sun gear 33;

[0068] 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.

[0069] Specifically, the bionic foot structure refers to a structure that mimics the human foot. The footplate 20 mimics the human foot, contacting the ground and supporting the bionic foot structure; the ankle 10 mimics the human ankle, enabling the 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 and the footplate 20. The footplate 20 has a large rotation angle and 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 rotation angle and speed of the footplate 20. The rotational speeds and angles of the ring gear 31, planetary gear 32, and sun gear 33 in the planetary gear structure 30 are different. The ring gear 31 has a smaller rotation angle and lower speed, while the sun gear 33 has a larger rotation angle and higher speed. The ring gear 31 is rotatably connected to the damping structure 40, the sun gear 33 is connected to the ankle 10, and the planetary gear 32 is rotatably connected to the footplate 20. The foot plate 20 rotates at a large angle relative to the ankle 10, while the damping structure 40 has a small range of motion; the foot plate 20 rotates at a high speed relative to the ankle 10, while the damping structure 40 has a low speed of motion. The planetary gear structure 30 improves the matching between the damping structure 40 and the foot plate 20, enabling the bionic foot structure to rotate in a manner similar to that of a human foot.

[0070] In a preferred implementation of this invention, such as Figure 4 and Figure 10 As shown, the planetary gear structure 30 also includes:

[0071] Planetary carrier 34, mounted on foot plate 20;

[0072] The planetary gear 32 is rotatably mounted on the planet carrier 34.

[0073] Specifically, the planet carrier 34 is fixed to the foot plate 20, and the planet gear 32 rotates relative to the planet carrier 34. The planet carrier 34 is located inside the gear ring 31.

[0074] In a preferred implementation of this invention, such as Figures 3-6 As shown, the foot plate 20 includes:

[0075] Plate body 21;

[0076] The bracket 22 is disposed on the plate 21.

[0077] Specifically, the plate 21 contacts the ground, and the support 22 is located at the rear end of the plate 21. The planetary carrier 34 is located on the support 22. The ankle 10 is rotatably mounted on the support 22. The support 22 includes two upright plates, namely a first upright plate 221 and a second upright plate 222, which are connected by a shaft 223. The ankle 10 is rotatably mounted on the shaft 223, and a bearing can be arranged between the shaft 223 and the ankle 10. The planetary carrier 34 is located on the second upright plate 222.

[0078] In a preferred implementation of this invention, such as Figure 2 , Figure 3 , Figure 6 and Figure 11 As shown, the ankle 10 includes a first housing 11 and a second housing 12 that are interconnected.

[0079] Specifically, the first housing 11 is located between the first upright plate 221 and the second upright plate 222. A notch 121 is formed on the second housing 12 and is located at the corresponding position of the planetary gear structure 30. The notch 121 provides clearance between the second upright plate 222 and the planetary gear structure 30. A limiting part 111 is formed on the first housing 11, which limits the rotation range of the first housing 11 relative to the first upright plate 221, thus limiting the rotation range between the footplate 20 and the ankle 10.

[0080] In a preferred implementation of this invention, such as Figures 5-7 As shown, the damping structure 40 includes:

[0081] Hydraulic cylinder 41 is rotatably connected to foot plate 20 and gear ring 31 respectively;

[0082] A regulator 42 is disposed in the hydraulic cylinder 41 and configured to regulate the flow rate of hydraulic oil in the hydraulic cylinder 41.

[0083] Specifically, the damping structure 40 can be an adjustable damping structure. The damping structure 40 can be a hydraulic damping structure; for example, a hydraulic cylinder 41 contains hydraulic oil and a piston, with a piston rod connected to the piston. The cylinder is rotatably connected to the foot plate 20, specifically rotatably connected to the middle of the plate 21. Figure 4 and Figure 13 As shown, the piston rod is rotatably connected to the gear ring 31, specifically via a gear ring seat 35. The piston rod rotates relative to the gear ring seat 35. A bearing is disposed between the gear ring seat 35 and the planetary carrier 34, and the gear ring seat 35 rotates relative to the planetary carrier 34. When the gear ring 31 rotates, it drives the piston rod to extend and retract, thus moving the piston within the cylinder. The regulator 42 can adjust the flow rate of hydraulic oil within the cylinder, thereby adjusting the resistance experienced by the piston within the cylinder, and consequently adjusting the damping magnitude of the damping structure 40.

[0084] In a preferred implementation of this invention, such as Figure 2 , Figure 3 and Figure 4 As shown, the bionic foot structure also includes:

[0085] Drive component 50 is disposed on the ankle 10;

[0086] The ankle 10 is connected to the sun gear 33 via the drive assembly 50.

[0087] Specifically, the drive assembly 50 is disposed in the first housing 11. The drive assembly 50 drives the sun gear 33 to rotate. Since the sun gear 33 rotates simultaneously with the planetary gear 32 and the ring gear 31, and the ring gear 31 is rotatably 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 large, the sun gear 33 is not easy to rotate (it can remain stationary relative to the footplate 20). When the drive assembly 50 drives the sun gear 33 to rotate, a larger relative rotation angle between the ankle 10 and the footplate 20 can be achieved more quickly. If the damping of the damping structure 40 is small, the sun gear 33 rotates easily. When the drive assembly 50 drives the sun gear 33 to rotate, it will not only cause the sun gear 33 to rotate relative to the footplate 20, realizing the extension and retraction of the damping structure 40, but will also achieve a smaller relative rotation angle between the ankle 10 and the footplate 20 more slowly. 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.

[0088] In a preferred embodiment of the present invention, the bionic foot structure further includes:

[0089] A motion state sensor is configured to detect the motion state of the bionic foot structure;

[0090] The controller is electrically connected to the motion state sensor, the damping structure 40, and the drive assembly 50, respectively.

[0091] Specifically, the motion state sensor can detect the motion state of the bionic foot structure, including at least one of the following: a stationary state, a walking state, and a running state. The stationary state can be a squatting state, a standing state, a semi-squatting state, etc. The walking state can be a slow walking state or a fast walking state. The running state can be a jogging state or a sprinting state. The motion state sensor can be an accelerometer, a gyroscope, a magnetometer, an ultrasonic sensor, etc. The installation location of the motion state sensor can be determined as needed, and it can be installed on the ankle 10, the foot plate 20, or the planetary gear structure 30. The controller can be located inside the second housing 12 and electrically connected to a power source.

[0092] In a preferred implementation of this invention, such as Figures 5-7 As shown, the drive component 50 includes:

[0093] Drive element 51 is disposed on the ankle 10;

[0094] The worm gear 52 is disposed on the output shaft of the drive component 51;

[0095] The turbine 53 is connected to the sun gear 33 and meshes with the worm 52.

[0096] Specifically, the drive unit 51 drives the worm gear 52 to rotate, which in turn drives the turbine 53 and the sun gear 33 to rotate. The drive unit 51 is disposed in the first housing 11, which covers the drive unit 51, the worm gear 52, and the turbine 53. The bionic foot structure also includes a power supply, which can be configured in the second housing 12, and supplies power to the drive assembly 50 and the motion state sensor.

[0097] In a preferred implementation of this invention, such as Figure 9 , Figure 12 and Figure 15 As shown, a first shaft hole 331 is formed on the sun gear 33, and a second shaft hole 531 is formed on the turbine 53; a shaft portion 223 is provided on the foot plate 20, the shaft portion 223 passes through the first shaft hole 331 and the second shaft hole 531 in sequence, and a connecting member 54 is sleeved on the shaft portion 223, the two ends of the connecting member 54 are respectively connected to the turbine 53 and the sun gear 33.

[0098] Specifically, a first shaft hole 331 is formed on the sun gear 33, and a second shaft hole 531 is formed on the worm gear 53. A shaft portion 223 passes through the first shaft hole 331 and the second shaft hole 531. The shaft portion 223 is mounted on the foot plate 20 and can be fixed to it. Both the sun gear 33 and the worm gear 53 rotate relative to the shaft portion 223, and the sun gear 33 and the worm gear 53 are connected by a connector 54 (see [link]). Figure 9 and Figure 14 The connecting member 54 can be a bushing, which is fitted over the shaft 223, and the sun gear 33, the connecting member 54, and the worm gear 53 rotate together. The shaft 223 is mounted on the bracket 22.

[0099] Based on the bionic foot structure described in any of the above embodiments, the present invention also provides a preferred embodiment of a bionic robot.

[0100] The bionic robot of this invention includes a bionic foot structure as described in any of the above embodiments.

[0101] Based on the bionic foot structure described in any of the above embodiments, the present invention also provides a preferred embodiment of a control method for the bionic foot structure.

[0102] The control method for the bionic foot structure according to an embodiment of the present invention includes the following steps:

[0103] Step S100: Based on the motion state sensor, acquire the motion state of the bionic foot structure;

[0104] Step S200: Control the drive assembly and control the damping structure according to the motion state.

[0105] Specifically, based on motion state sensors, the motion state of the bionic foot structure is determined, including at least one of a stationary state, a walking state, and a running state. Then, according to the motion state, the drive component and the damping structure are controlled. Specifically, the drive component is controlled to realize the 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.

[0106] Step S200 specifically includes:

[0107] Step S210: Based on the static state, control the damping structure to increase the damping value and pause the control drive component;

[0108] Step S220: Based on the walking state, control the damping structure to maintain the damping value and control the drive component to maintain the drive frequency;

[0109] Step S230: Based on the running state, control the damping structure to reduce the damping value and control the drive component to increase the drive frequency.

[0110] 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 to facilitate the user's walking. The driving frequency refers to the frequency at which the foot plate rotates 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 foot plate to rotate relative to the ankle at the driving frequency to assist the user's walking. When the bionic foot structure is in the stationary state, the damping structure needs to be controlled to increase the damping value, and the driving component needs to be paused. Because the damping value of the damping structure is relatively large, the gear ring, planetary gears, and sun gear are not easy to rotate, and the worm gear and worm are also not easy to rotate, and the foot plate and ankle are also not easy to rotate. When the bionic foot structure is in the running state, the damping structure needs to be controlled to decrease the damping value, and the driving component needs to be controlled to increase the driving frequency to adapt to the frequency of the foot plate's back and forth rotation when the user is running.

[0111] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A biomimetic foot structure, characterized in that, include: ankle; The footplate is rotatably connected to the ankle. Planetary gear structure; The planetary gear structure includes: a gear ring, planetary gears, and a sun gear. The planetary gears and the sun gear are both located within the gear ring, and the planetary gears mesh with the sun gear and the gear ring, respectively. The planetary gears are rotatably connected to the footplate, 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; The damping structure includes: Hydraulic cylinders are rotatably connected to the foot plate and the gear ring, respectively. A regulator is disposed in the hydraulic cylinder and configured to regulate the flow rate of hydraulic oil in the hydraulic cylinder; The bionic foot structure also includes: A drive component is located on the ankle; The ankle is connected to the sun gear via the drive assembly.

2. The bionic foot structure according to claim 1, characterized in that, The bionic foot structure also includes: A motion state sensor is 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 drive assembly, respectively.

3. The bionic foot structure according to claim 2, characterized in that, The driving component includes: A drive unit is located at the ankle; A worm gear is disposed on the output shaft of the drive component; The worm gear is connected to the sun gear and meshes with the worm.

4. The bionic foot structure according to claim 3, characterized in that, The sun gear has a first shaft hole, and the worm gear has 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 member is sleeved on the shaft portion, and the two ends of the connecting member are respectively connected to the worm gear and the sun gear.

5. The bionic foot structure according to claim 4, characterized in that, The footplate includes: plate body; A bracket is provided on the plate. The bracket is provided with the shaft portion.

6. A biomimetic robot, characterized in that, include: The bionic foot structure as described in any one of claims 1 to 5.

7. A control method for the bionic foot structure as described in any one of claims 2 to 5, characterized in that, Including the following steps: Based on motion state sensors, the motion state of the bionic foot structure is acquired; Based on the motion state, control the drive components and control the damping structure.

8. The control method for the bionic foot structure according to claim 7, characterized in that, The motion state includes at least one of the following: a stationary state, a walking state, and a running state; The step of controlling the drive component and the damping structure according to the motion state includes: Based on the static state, the damping structure is controlled to increase the damping value, and the control drive component is paused; Based on the walking state, the damping structure is controlled to maintain the damping value, and the drive components are controlled to maintain the drive frequency. Based on the running state, the damping structure is controlled to decrease the damping value, and the drive component is controlled to increase the drive frequency.

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