Variable-stiffness knee joint, rehabilitation walking-aid exoskeleton and control method of rehabilitation walking-aid exoskeleton

Abstract

The invention provides a rigidity-variable knee joint, a rehabilitation walking-aid exoskeleton and a control method thereof, relates to the technical field of exoskeletons, and solves the technical problems that in the prior art, motor series elastic driving is poor in flexibility, and user experience is affected. The rigidity-variable knee joint, the rehabilitation walking-aid exoskeleton and the control method thereof comprise a rotation driving device, a thigh assembly and a shank assembly, wherein the thigh assembly and the shank assembly are rotationally connected; a variable stiffness assembly is arranged between the thigh assembly and the shank assembly; the variable stiffness assembly can adjust the stiffness between the thigh assembly and the shank assembly in real time according to the positions of the thigh assembly and the shank assembly. According to the variable-stiffness knee joint, the rehabilitation walking-aid exoskeleton and the control method thereof, the driving flexibility is improved, accurate output of the driving torque is achieved, and the comfort degree of a user is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of exoskeletons, and in particular to a variable stiffness knee joint, a rehabilitation and walking assistance exoskeleton and a control method thereof. Background Art

[0002] In the civilian field, the knee joint walking assistance exoskeleton can assist the lower limbs of the human body to walk normally and assist the elderly and people with weak mobility to walk; in the medical field, the knee joint walking assistance exoskeleton can assist the precise rehabilitation training of groups with knee joint injuries, knee osteoarthritis, etc., and accelerate the rehabilitation process.

[0003] At present, the knee joint walking assistance exoskeleton mainly includes direct motor drive, motor wire drive, etc. Direct motor drive is the mainstream drive method, with the advantages of simple drive structure, better assistance and support effect, and can provide assistance in both the extension and flexion directions of the knee joint; the motor wire drive has a lower transmission efficiency, and problems such as wire winding and wire jamming are likely to occur in the wire drive structure. At the same time, it can only drive the knee joint to extend and cannot provide assistance for the knee joint flexion.

[0004] Existing rehabilitation and walking assistance exoskeletons generally have problems of poor driving compliance and accurate torque output. To solve these two problems, currently, it is mainly considered to solve from two aspects. One is to adopt motor series elastic drive to improve the driving compliance from the level of the drive structure. The other is to adopt a neural network intelligent algorithm to improve the control accuracy and improve the driving compliance and the accuracy of torque output from the level of the control algorithm.

[0005] However, the motor series elastic drive has problems of certain driving delay, poor compliance, and inability to achieve accurate torque output control; at the same time, the adoption of the neural network intelligent algorithm has problems such as complex calculation and the need for a large amount of data training. Summary of the Invention

[0006] The purpose of the present invention is to provide a variable stiffness knee joint, a rehabilitation and walking assistance exoskeleton and a control method thereof, so as to solve the technical problem that the motor series elastic drive in the prior art has poor compliance and affects the user experience. The preferred technical solutions provided by the present invention can produce many technical effects as described below.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] The variable stiffness knee joint provided by the present invention includes a rotational drive device, a thigh component and a calf component;

[0009] The thigh component and the calf component are rotatably connected, and a variable stiffness component is arranged between the thigh component and the calf component;

[0010] The variable stiffness component includes a paddle component and a groove component. The paddle component is disposed on one of the thigh component and the calf component, and the groove component is disposed on the other of the thigh component and the calf component.

[0011] The paddle component includes at least two swinging paddles, the groove component includes at least two positioning grooves, and at least two of the swinging paddles are arranged in sequence along the radial direction of the rotation center of the thigh component and the calf component. At least two positioning grooves are correspondingly arranged with at least two swinging paddles.

[0012] Rigid springs are arranged in at least two of the positioning grooves, and the stiffness of the rigid springs in at least two of the positioning grooves is arranged from small to large. The rotation driving device drives the calf component and the thigh component to rotate, enabling at least two of the swinging paddles to rotate along at least two of the positioning grooves respectively, and capable of compressing the rigid springs in sequence from the one with small stiffness to the one with large stiffness.

[0013] Optionally, two sets of rigid springs are arranged in each of the positioning grooves, and the two sets of rigid springs are respectively arranged on both sides of the swinging paddle.

[0014] Optionally, multiple sets of the paddle component and the groove component are provided, and multiple sets of the paddle component and multiple sets of the groove component are arranged in a circular array.

[0015] Optionally, four sets of the paddle component and the groove component are provided.

[0016] And / or, the paddle component includes three swinging paddles, and the groove component includes three positioning grooves.

[0017] Optionally, from the rotation center of the thigh component and the calf component outwards, the stiffness of the rigid springs in the three positioning grooves is arranged from small to large.

[0018] Optionally, the rotation driving device includes a battery component, a motor, and a planetary gear reducer. The output shaft of the planetary gear reducer is connected to the calf component or the thigh component, and the motor is connected to the planet carrier of the planetary gear reducer.

[0019] The planetary gear reducer includes a reducer housing, an internal gear ring, a sun gear, planetary gears, and a planet carrier. The planetary gears are simultaneously meshed with the sun gear and the internal gear ring. The planet carrier is connected to the planetary gears, and an output shaft is provided on the sun gear.

[0020] Under the same inventive concept, the present invention further provides a rehabilitation walking exoskeleton, including the variable stiffness knee joint as described above.

[0021] A rehabilitation walking assist exoskeleton control method is applied to the rehabilitation walking assist exoskeleton as described above. The control method includes:

[0022] Obtain initial data and real-time data. The initial data is the data information of the rotation drive device, thigh component, and calf component when the user wears it. The real-time data is the data information of the rotation drive device, thigh component, and calf component when the user walks.

[0023] According to the initial data and the real-time data, determine the target stage corresponding to the current gait phase of the knee joint, and obtain the expected stiffness value information of the current target stage.

[0024] Control the rotation of the rotation drive device according to the current expected stiffness value information.

[0025] Optionally, according to the initial data and the real-time data, determine the target stage corresponding to the current gait phase of the knee joint, and obtain the expected stiffness value information of the current target stage, including:

[0026] The initial data and the real-time data include plantar pressure data information. According to the plantar pressure data information, determine whether the current gait phase of the knee joint is in the stance phase or the swing phase.

[0027] According to the initial data and the real-time data, determine the knee joint angle data information and the knee joint angular velocity data information.

[0028] According to the knee joint angle data, determine the early stance phase, mid-stance phase, or late stance phase. According to the knee joint angular velocity data information, determine the swing extension phase or the swing flexion phase.

[0029] Optionally, controlling the rotation of the rotation drive device according to the current expected stiffness value information includes:

[0030] Calculate the compression angle information of the rigid spring according to the current expected stiffness value information and the knee joint angle data information.

[0031] Control the rotation of the rotation drive device according to the compression angle information of the rigid spring.

[0032] The beneficial effects of the present invention are as follows: The variable-stiffness knee joint, rehabilitation and walking assistance exoskeleton and its control method provided by the present invention include a rotational driving device, a thigh component, and a calf component. A variable-stiffness component is arranged between the thigh component and the calf component. The variable-stiffness component includes a paddle component and a groove component. The paddle component and the groove component are respectively arranged on the thigh component and the calf component. The paddle component includes at least two swing paddles, and the groove component includes at least two positioning grooves. At least two of the swing paddles are arranged in sequence along the radial direction of the rotation center of the thigh component and the calf component. At least two positioning grooves are arranged corresponding to at least two swing paddles. When the thigh component and the calf component rotate, at least two groups of positioning paddles can be driven to rotate, and at least two groups of positioning paddles can move along the positioning grooves. Rigid springs are arranged in at least two of the positioning grooves, and the stiffnesses of the rigid springs in at least two of the positioning grooves are arranged from small to large. The rotational driving device drives the calf component and the thigh component to rotate, enabling at least two of the swing paddles to rotate along at least two of the positioning grooves and sequentially compress the rigid springs in the order of small stiffness to large stiffness, so as to be able to change the current stiffness value according to the current position of the knee joint, realize the stiffness change in different gait phases, improve the compliance of the drive, achieve the accurate output of the driving torque, and improve the user comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 is a perspective view of the present invention;

[0035] Figure 2 is a partial structural schematic diagram of the present invention;

[0036] Figure 3 is a structural schematic diagram of the thigh component of the present invention;

[0037] Figure 4 is a structural schematic diagram of the calf component of the present invention;

[0038] Figure 5 is a structural schematic diagram of the planetary gear reducer of the present invention.

[0039] In the figure:

[0040] 1, rotational driving device; 2, thigh component; 3, variable-stiffness component; 4, calf component;

[0041] 11. Battery assembly; 12. Motor; 13. Planetary gear reducer; 131. Internal gear ring; 132. Sun gear; 133. Planet gear; 134. Planet carrier;

[0042] 21. Thigh plate; 22. Thigh strap;

[0043] 31. Paddle assembly; 32. Groove assembly; 33. Rigid spring;

[0044] 311. Swing paddle; 321. Positioning groove; 331. First - stage large rigid spring; 332. Second - stage large rigid spring; 333. Third - stage large rigid spring; 334. First - stage small rigid spring; 335. Second - stage small rigid spring; 336. Third - stage small rigid spring;

[0045] 40. Calf plate; 41. Footrest plate; 42. Footrest; 43. Footrest connecting piece; 44. Ankle joint connecting piece; 45. Footrest connecting piece; 46. Footrest rod; 47. Footrest rod limit; 48. Calf strap. Detailed implementation mode

[0046] The following can refer to the drawings Figures 1 to 5 and the text content to understand the content of the present invention and the differences between the present invention and the prior art. The following further describes the technical solutions (including preferred technical solutions) of the present invention by way of the drawings and by listing some alternative embodiments of the present invention. It should be noted that: Any technical feature and any technical solution in this embodiment are one or several of a variety of alternative technical features or alternative technical solutions. For the sake of concise description, all alternative technical features and alternative technical solutions of the present invention cannot be exhausted in this document, nor is it convenient to emphasize that each implementation manner of each technical feature is one of the alternative multiple implementation manners. Therefore, those skilled in the art should know that: Any technical means provided by the present invention can be replaced, or any two or more technical means or technical features provided by the present invention can be combined with each other to obtain a new technical solution. Any technical feature and any technical solution within this embodiment do not limit the protection scope of the present invention. The protection scope of the present invention should include any alternative technical solution that those skilled in the art can think of without creative work and any new technical solution obtained by those skilled in the art by combining any two or more technical means or technical features provided by the present invention.

[0047] In the description of the present invention, it should be noted that unless otherwise specified, the meaning of "a plurality of" is two or more; the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, terms such as "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0048] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] The present invention provides a variable stiffness knee joint, a rehabilitation and walking assistance exoskeleton and its control method, which can improve the compliance of driving, achieve accurate output of driving torque, and improve the comfort of users.

[0050] The following will Figures 1 to 5 elaborate on the technical solutions provided by the present invention in more detail.

[0051] The present invention provides a variable stiffness knee joint, which includes a rotational driving device 1, a thigh component 2 and a calf component 4;

[0052] The thigh component 2 and the calf component 4 are rotationally connected, and a variable stiffness component 3 is arranged between the thigh component 2 and the calf component 4;

[0053] The variable stiffness component 3 includes a flap component 31 and a groove component 32. The flap component 31 is arranged on one of the thigh component 2 and the calf component 4, and the groove component 32 is arranged on the other of the thigh component 2 and the calf component 4;

[0054] The flap component 31 includes at least two swing flaps 311, the groove component 32 includes at least two positioning grooves 321, and at least two swing flaps 311 are arranged in sequence along the radial direction of the rotation center of the thigh component 2 and the calf component 4, and at least two positioning grooves 321 are arranged corresponding to at least two swing flaps 311;

[0055] At least two of the positioning grooves 321 are each provided with a rigid spring 33, and the stiffness of the rigid springs 33 in at least two of the positioning grooves 321 is arranged from small to large. The rotation driving device 1 drives the lower leg assembly 4 and the thigh assembly 2 to rotate, enabling at least two of the swing paddles 311 to rotate along at least two of the positioning grooves 321 respectively, and sequentially compressing the rigid springs 33 in the order of small stiffness to large stiffness.

[0056] The variable stiffness knee joint provided by the present invention includes a rotation driving device 1, a thigh assembly 2, and a lower leg assembly 4. A variable stiffness assembly 3 is provided between the thigh assembly 2 and the lower leg assembly 4. The variable stiffness assembly 3 includes a paddle assembly 31 and a groove assembly 32. The paddle assembly 31 and the groove assembly 32 are respectively provided on the thigh assembly 2 and the lower leg assembly 4. The paddle assembly 31 includes at least two swing paddles 311, and the groove assembly 32 includes at least two positioning grooves 321. At least two of the swing paddles 311 are sequentially arranged along the radial direction of the rotation center of the thigh assembly 2 and the lower leg assembly 4. At least two positioning grooves 321 are correspondingly arranged with at least two swing paddles 311. When the thigh assembly 2 and the lower leg assembly 4 rotate, at least two groups of positioning paddles can be driven to rotate, and at least two groups of positioning paddles can move along the positioning grooves 321. At least two of the positioning grooves 321 are each provided with a rigid spring 33, and the stiffness of the rigid springs 33 in at least two of the positioning grooves 321 is arranged from small to large. The rotation driving device 1 drives the lower leg assembly 4 and the thigh assembly 2 to rotate, enabling at least two of the swing paddles 311 to rotate along at least two of the positioning grooves 321 respectively, and sequentially compressing the rigid springs 33 in the order of small stiffness to large stiffness, so as to be able to change the current stiffness value according to the current position of the knee joint, realize the stiffness change in different gait phases, improve the compliance of the drive, realize the accurate output of the driving torque, and improve the user comfort.

[0057] It can be understood that at least two of the swing paddles 311 are sequentially arranged along the radial direction of the rotation center of the thigh assembly 2 and the lower leg assembly 4. The distances of at least two swing paddles 311 from the center are different. At least two positioning grooves 321 are correspondingly arranged with at least two swing paddles 311, and the distances of at least two positioning grooves 321 from the rotation center are also different. When the leg assembly and the lower leg assembly 4 rotate, at least two groups of positioning paddles can move along at least two groups of positioning grooves 321 respectively. Rigid springs 33 are provided in at least two of the positioning grooves 321. When at least two swing paddles 311 rotate along at least two positioning grooves 321, the rigid springs 33 can be sequentially compressed in the order of small stiffness to large stiffness, so as to be able to change the stiffness when the thigh assembly 2 and the lower leg assembly 4 rotate.

[0058] That is to say, when the swing paddle 311 rotates, the first swing paddle 311 first compresses the rigid spring 33 with a small stiffness. As the rotation continues, the second swing paddle 311 will then compress the rigid spring 33 with a larger stiffness. At this time, at least two swing paddles 311 simultaneously compress the rigid springs 33 in at least two positioning grooves 321, and the torsional stiffness of the knee joint increases as the compression angle of the rigid spring 33 increases.

[0059] It should be noted that during the flexion and extension of the knee joint, there are significant differences in the stiffness of the knee joint. For example: in the support state, when the heel touches the ground and the knee joint flexes slightly, the stiffness of the knee joint is the largest; from the heel touching the ground to the sole completely touching the ground, the knee joint extends and the stiffness of the knee joint is relatively large; from the sole completely touching the ground to only the toes touching the ground, the knee joint flexes and the stiffness of the knee joint is relatively small; in the swing state, when the sole completely leaves the ground and the knee joint flexes, the stiffness of the knee joint is relatively small; from the sole completely leaving the ground to the sole touching the ground and the knee joint extending, the stiffness of the knee joint is relatively small. By combining different stiffness values in different states and adopting the variable-stiffness knee joint provided by the present invention, the adjustment of stiffness can be achieved, thereby improving the compliance of driving, realizing the accurate output of driving torque, and improving user comfort.

[0060] In some embodiments of the present invention, two sets of rigid springs 33 are provided in each of the positioning grooves 321, and the two sets of rigid springs 33 are respectively arranged on both sides of the swing paddle 311.

[0061] In some of the above embodiments of the present invention, two sets of rigid springs 33 are provided in the positioning groove 321, and the two sets of rigid springs 33 are respectively arranged on both sides of the swing paddle 311, so that the swing paddle 311 can achieve stiffness adjustment both during forward rotation and reverse rotation, making the stiffness adjustment during the flexion and extension of the knee joint more accurate, further improving the compliance of driving, realizing the accurate output of driving torque, and improving user comfort.

[0062] It can be understood that the two sets of rigid springs 33 are arranged in the positioning groove 321, and the stiffness of the two sets of rigid springs 33 can be selected according to the actual situation to meet the requirements of different stiffnesses during flexion and extension.

[0063] It should be emphasized that when at least two sets of swing paddles 311 rotate along at least two sets of the positioning grooves 321 respectively, they all compress the rigid springs 33 in the order from small stiffness to large stiffness. Whether it is forward rotation or reverse rotation, the torsional stiffness of the knee joint increases as the compression angle of the spring increases.

[0064] In some specific embodiments of the present invention, the paddle assembly 31 is arranged on the calf assembly 4, the groove assembly 32 is arranged on the thigh assembly 2, the rotation driving device 1 is arranged on the thigh assembly 2, and the output shaft of the rotation driving device 1 is connected to the calf assembly 4.

[0065] The rotation driving device 1 drives the calf assembly 4 to rotate forward or backward. The swing paddle 311 on the calf assembly 4 can rotate along the positioning groove 321, compressing the rigid spring 33 in the positioning groove 321.

[0066] In some embodiments of the present invention, multiple sets of the paddle assembly 31 and the groove assembly 32 are provided, and multiple sets of the paddle assembly 31 and multiple sets of the groove assembly 32 are arranged in a circular array.

[0067] In some of the above embodiments of the present invention, multiple sets of the paddle assembly 31 and the groove assembly 32 are provided, and multiple sets of the paddle assembly 31 and multiple sets of the groove assembly 32 are arranged in a circular array, which can ensure that the rotation of the knee joint is more compliant, realize the accurate output of the driving torque, and improve the user comfort.

[0068] It can be understood that the cooperation of multiple sets of the groove assembly 32 and the paddle assembly 31 can make the structure more stable when the thigh assembly 2 and the calf assembly 4 rotate, the stiffness control more accurate, and the service life of the rigid spring 33 greatly improved.

[0069] In some embodiments of the present invention, four sets of the paddle assembly 31 and the groove assembly 32 are provided;

[0070] And / or, the paddle assembly 31 includes three swing paddles 311, and the groove assembly 32 includes three positioning grooves 321.

[0071] In some of the above embodiments of the present invention, four sets of the paddle assembly 31 and the groove assembly 32 are provided. The four sets of the paddle assembly 31 and multiple sets of the groove assembly 32 are arranged in a circular array, forming a more stable structure, and can ensure the rotation requirements of the knee joint, and at the same time can control the stiffness more accurately, improving the user comfort.

[0072] Specifically, the radian angle of the positioning groove 321 of each set of the groove assembly 32 is 90 degrees, and the four sets of the groove assembly 32 are integrally arranged on the variable stiffness disk, and the variable stiffness disk is fixedly connected to the thigh assembly.

[0073] The paddle assembly 31 includes three swing paddles 311, and the groove assembly 32 includes three positioning grooves 321. Rigid springs 33 are respectively arranged in the three positioning grooves 321, constituting a regulation of high, medium, and low three-level stiffness, with a wider regulation range, better driving compliance, and more accurate output of driving torque, improving user comfort.

[0074] In some embodiments of the present invention, starting from the rotation centers of the thigh assembly 2 and the calf assembly 4 outward, the stiffness of the rigid springs 33 in the three positioning grooves 321 is arranged from small to large.

[0075] In some of the above embodiments of the present invention, the swing paddle 311 close to the center first compresses the rigid spring 33 with small rigidity close to the center, and then sequentially compresses the other two rigid springs 33 with gradually increasing stiffness away from the center, so that the torsional stiffness of the knee joint can increase as the compression angle of the rigid spring 33 increases.

[0076] Specifically, the rigid springs 33 in the three positioning grooves 321 are sequentially divided into first-level, second-level, and third-level from the center outward, and the stiffness of the rigid springs 33 compressed by the forward rotation of the swing paddle 311 and the stiffness of the rigid springs 33 compressed by the reverse rotation are different, which are large rigid springs and small rigid springs respectively.

[0077] Among them, when the three swing paddles 311 rotate forward, they sequentially compress the first-level large rigid spring 331, the second-level large rigid spring 332, and the third-level large rigid spring 333. The compression stiffness of the rigid spring 33 is converted into torsional stiffness, and the torsional stiffness increases from the first level to the third level. At this time, the corresponding stiffness magnitudes are: forward first level, forward second level, forward third level.

[0078] When the three swing paddles 311 rotate reversely, they sequentially compress the first-level small rigid spring 334, the second-level small rigid spring 335, and the third-level small rigid spring 336. At this time, the corresponding stiffness magnitudes are: reverse first level, reverse second level, reverse third level.

[0079] It can be understood that when the three swing paddles 311 rotate forward, the innermost swing paddle 311 first compresses the first-level large rigid spring 331, and then the middle swing paddle 311 compresses the second-level large rigid spring 332. At this time, the innermost swing paddle 311 is still in the state of compressing the first-level large rigid spring 331; finally, the outermost swing paddle 311 compresses the third-level large rigid spring 333. At this time, the innermost swing paddle 311 is still in the state of compressing the first-level large rigid spring 331, and the middle swing paddle 311 is in the state of compressing the second-level large rigid spring 332. The same is true for reverse rotation.

[0080] In some embodiments of the present invention, the rotation driving device 1 includes a battery assembly 11, a motor 12, and a planetary gear reducer 13. The output shaft of the planetary gear reducer 13 is connected to the calf assembly 4 or the calf assembly 4, and the motor 12 is connected to the planet carrier 134 of the planetary gear reducer 13;

[0081] The planetary gear reducer 13 includes a reducer housing, an internal gear ring 131, a sun gear 132, planetary gears 133, and a planet carrier 134. The planetary gears 133 are simultaneously meshed with the sun gear 132 and the internal gear ring 131. The planet carrier 134 is connected to the planetary gears 133, and an output shaft is provided on the sun gear 132.

[0082] In some of the above embodiments of the present invention, power is provided by the battery assembly 11, and the motor 12 outputs power through the planetary gear reducer 13 to drive the thigh assembly 2 and the calf assembly 4 to rotate. The battery assembly 11 includes a battery housing, a battery fixedly connected to the battery housing, a battery cover fixedly connected to the battery housing, wire outlet holes and charging holes distributed on the battery housing, switch mounting holes distributed on the battery cover, and fixing clips distributed on the battery housing. Since the battery assembly 11 and the planetary gear reducer 13 are common technical means in the art, they will not be elaborated here.

[0083] In some embodiments of the present invention, a thigh attitude sensor is provided on the thigh assembly 2, and a calf attitude sensor and a plantar pressure sensor are provided on the calf assembly 4.

[0084] In some of the above embodiments of the present invention, data information such as thigh angle, angular velocity, calf angle, angular velocity, and plantar pressure data can be obtained through the thigh attitude sensor, the calf attitude sensor, and the plantar pressure sensor.

[0085] In some embodiments of the present invention, the thigh assembly 2 includes a thigh plate 21 and at least one thigh strap 22, and the calf assembly 4 includes a calf plate 40, at least one calf strap 48, a footrest plate 41, a footrest 42, an ankle joint connector 44, and a footrest rod 46. The footrest rod 46 is connected to the calf plate 40. The bottom of the ankle joint connector 44 is rotatably connected to a footrest connector 45 on the footrest plate 41. The top of the ankle joint connector 44 is connected to the footrest rod 46 through a footrest rod 46 connector, and the top of the ankle joint connector 44 is rotatably connected to the footrest rod 46 connector, and the rotation axes at the top and bottom of the ankle joint connector 44 are perpendicular to each other.

[0086] It should be noted that the footrest 42 is provided on the footrest plate 41, and the elastic bandages for fixing the user's feet provided on the footrest plate 41 are all conventional technical means in the art and will not be elaborated here.

[0087] In some embodiments of the present invention, an adjustment groove and an adjustment member are provided on the calf plate 40. A plurality of holes are provided in the length direction of the foot support rod 46. The foot support rod 46 is adapted to the adjustment groove, and the foot support rod 46 can slide along the adjustment groove, and the foot support rod 46 is locked on the calf plate 40 by the cooperation of the adjustment member and the holes.

[0088] In some of the above embodiments of the present invention, by providing an adjustment groove between the foot support rod 46 and the calf plate 40, the foot support rod 46 can be slidably arranged in the adjustment groove, and adjustment holes are provided on the foot support rod 46. The positions of the foot support rod 46 and the calf plate 40 can be fixed by the adjustment member, thereby realizing the adjustment of the position between the foot support rod 46 and the calf plate 40, and meeting the usage requirements of users with different heights and different leg lengths.

[0089] Specifically, the adjustment member includes a split pin flange and a split pin. The split pin is threadedly connected to the split pin flange, and the split pin can be inserted into the adjustment hole to fix the foot support rod 46 and the calf plate 40.

[0090] More specifically, a foot support rod limit 47 is provided on the calf plate 40 for limiting the extreme position of the movement of the foot support rod 46. A plantar pressure sensor is provided on the foot support plate 41.

[0091] The present invention also provides a rehabilitation walking assist exoskeleton, including the variable stiffness knee joint as described above.

[0092] The rehabilitation walking assist exoskeleton provided by the present invention includes the variable stiffness knee joint as described above, and has the beneficial effects of being able to change the current stiffness value according to the current position of the knee joint, realizing the stiffness change in different gait phases, improving the driving compliance, realizing the accurate output of the driving torque, and improving the user comfort.

[0093] The present invention also provides a control method for a rehabilitation walking assist exoskeleton, which is applied to the rehabilitation walking assist exoskeleton as described above. The control method includes:

[0094] Obtaining initial data and real-time data, where the initial data is the data information of the rotation of the driving device 1, the thigh assembly 2, and the calf assembly 4 when the user wears it, and the real-time data is the data information of the rotation of the driving device 1, the thigh assembly 2, and the calf assembly 4 when the user walks;

[0095] According to the initial data and the real-time data, determining the target stage corresponding to the current gait phase of the knee joint, and obtaining the expected stiffness value information of the current target stage;

[0096] Controlling the rotation of the driving device 1 to rotate according to the current expected stiffness value information.

[0097] The rehabilitation walking exoskeleton control method provided by the present invention includes obtaining initial data and real-time data. According to the initial data and the real-time data, the target stage corresponding to the current gait phase of the knee joint can be determined, and the expected stiffness value information of the current target stage can be obtained. According to the current expected stiffness value information, the rotation driving device 1 can be controlled to rotate, so as to adjust the current stiffness value of the knee joint and improve the user's comfort.

[0098] In some embodiments of the present invention, according to the initial data and the real-time data, the target stage corresponding to the current gait phase of the knee joint is determined, and the expected stiffness value information of the current target stage is obtained, including:

[0099] The initial data and the real-time data include plantar pressure data information. According to the plantar pressure data information, it is determined whether the current gait phase of the knee joint is in the stance phase or the swing phase;

[0100] According to the initial data and the real-time data, the knee joint angle data information and the knee joint angular velocity data information are determined;

[0101] According to the knee joint angle data, the early stance phase, the mid-stance phase or the late stance phase is determined. According to the knee joint angular velocity data information, the swing extension phase or the swing flexion phase is determined.

[0102] In some of the above embodiments of the present invention, the stance phase and the swing phase are determined according to the plantar pressure data threshold method. The plantar pressure data higher than a certain threshold is the stance phase, and vice versa is the swing phase. The early, middle and late stages of the stance phase are determined according to the differential zero point of the stance-phase knee joint angle. The swing extension phase and the swing flexion phase are determined according to the positive and negative of the knee joint angular velocity data.

[0103] Specifically, according to the angle data and angular velocity data provided by the attitude sensors of the thigh component 2 and the calf component 4, and the plantar pressure data provided by the plantar pressure sensor, the gait phase during walking is divided. According to the different knee joint torsional stiffness and driving directions provided, it is mainly divided into five stages: the early stance phase, the mid-stance phase, the late stance phase, the swing flexion phase, and the swing extension phase:

[0104] At the early stance phase, the heel touches the ground, the knee joint flexes slightly, the knee joint stiffness is the largest, the rotation driving device 1 drives the knee joint to extend forward to provide buffering for the heel to touch the ground, and the swing flap 311 compresses the rigid spring 33 to the three-stage large rigid spring 333 group to provide the maximum three-stage stiffness in the forward direction.

[0105] In the middle stage of the support state, from heel strike to full foot contact with the ground, the knee joint is straight, the knee joint stiffness is relatively large, the rotational drive device 1 drives forward to provide assistance for straightening the knee joint and plays a supporting role. The swing flap 311 compresses the 33 groups of rigid springs to the 332 groups of large rigid springs of the second level, providing the second-level positive stiffness.

[0106] In the late stage of the support state, from full foot contact with the ground to only the toes touching the ground, the knee joint flexes, the knee joint stiffness is relatively small, the forward drive of the rotational drive device 1 plays a certain supporting role, and the swing flap 311 compresses the 33 groups of rigid springs to the 331 groups of large rigid springs of the first level, providing the first-level positive stiffness.

[0107] In the flexion period of the swing state, the sole of the foot is completely off the ground and the knee joint flexes. The knee joint stiffness is relatively small. The reverse drive of the rotational drive device 1 provides assistance for flexing the knee joint. The swing flap 311 compresses the 33 groups of rigid springs to the 334 groups of small rigid springs of the first level, providing the first-level reverse stiffness.

[0108] In the extension period of the swing state, from the sole of the foot being completely off the ground to the sole of the foot touching the ground and the knee joint being straight, the knee joint stiffness is relatively small. The forward drive of the rotational drive device 1 provides assistance for straightening the knee joint. The swing flap 311 compresses successively to the 331 groups of large rigid springs of the first level and the 332 groups of large rigid springs of the second level, providing the first-level positive stiffness and the second-level positive stiffness in sequence.

[0109] It should be noted that when using this rehabilitation and walking-assisting exoskeleton for assisting the walking of weak walkers, only compressing to the 334 groups of small rigid springs of the first level and providing the first-level reverse stiffness can meet the usage requirements.

[0110] When a relatively large torque and stiffness are required for knee joint flexion, during the process from the sole of the foot being completely off the ground to being lifted in the flexion period of the swing state, the knee joint flexes, the knee joint stiffness is relatively large, the reverse drive of the rotational drive device 1 provides assistance for flexing the knee joint, and the swing flap 311 compresses the 33 groups of rigid springs to the 33 groups of rigid springs with small stiffness of the third level, providing the maximum third-level reverse stiffness.

[0111] In some embodiments of the present invention, controlling the rotation of the rotational drive device 1 according to the current desired stiffness value information includes:

[0112] Calculating the compression angle information of the rigid spring 33 according to the current desired stiffness value information and the knee joint angle data information;

[0113] Controlling the rotation of the rotational drive device 1 according to the compression angle information of the rigid spring 33.

[0114] In some of the above embodiments of the present invention, after determining the gait phase based on the plantar pressure data and the angle data of the thigh component 2 and the calf component 4, etc., according to the current knee joint angle, plantar pressure data, and the desired torsional stiffness, the compression angle of the current desired rigid spring 33 group is calculated, and the angle control is carried out with this as the target value, ultimately achieving a compliant angle output and an accurate torque output.

[0115] It can be understood that after calculating the compression angle information of the rigid spring 33, by obtaining the current output angle of the motor 12, the angle that the motor 12 needs to continue to output can be calculated, so that the rotation of the motor 12 can be controlled.

[0116] In the description of this specification, the description with reference to terms such as "example", "embodiment" or "some embodiments" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0117] Certainly, the present invention is not limited to the above embodiments. Those skilled in the art can make equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent variations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A variable stiffness knee joint, characterized in that, It includes a rotational drive device, a thigh component, and a calf component; The thigh component and the calf component are rotationally connected, and a variable stiffness component is provided between the thigh component and the calf component; The variable stiffness component includes a flap component and a groove component. The flap component is provided on one of the thigh component and the calf component, and the groove component is provided on the other of the thigh component and the calf component; The flap component includes at least two swing flaps, the groove component includes at least two positioning grooves, and at least two of the swing flaps are arranged in sequence along the radial direction of the rotation center of the thigh component and the calf component. At least two positioning grooves are arranged corresponding to at least two swing flaps; Rigid springs are arranged in at least two of the positioning grooves, and the stiffness of the rigid springs in at least two of the positioning grooves is arranged from small to large. The rotational drive device drives the calf component and the thigh component to rotate, enabling at least two of the swing flaps to rotate along at least two of the positioning grooves respectively, and capable of sequentially compressing the rigid springs in the order of small stiffness to large stiffness.

2. The variable stiffness knee joint according to claim 1, wherein Two sets of rigid springs are arranged in each of the positioning grooves, and the two sets of rigid springs are respectively arranged on both sides of the swing flap.

3. The variable-stiffness knee joint according to claim 1, wherein Multiple sets of the flap component and the groove component are provided, and multiple sets of the flap component and multiple sets of the groove component are arranged in a circular array.

4. The variable stiffness knee joint according to claim 3, characterized in that, Four sets of the flap component and the groove component are provided; And / or, the flap component includes three swing flaps, and the groove component includes three positioning grooves.

5. The variable stiffness knee joint according to claim 4, characterized in that, Outward from the rotation center of the thigh component and the calf component, the stiffness of the rigid springs in the three positioning grooves is arranged from small to large.

6. The variable stiffness knee joint according to claim 1, characterized in that, The rotational drive device includes a battery component, a motor, and a planetary gear reducer. The output shaft of the planetary gear reducer is connected to the calf component or the calf component, and the motor is connected to the planet carrier of the planetary gear reducer; The planetary gear reducer includes a reducer housing, an internal gear ring, a sun gear, planetary gears, and a planet carrier. The planetary gears are simultaneously meshed with the sun gear and the internal gear ring. The planet carrier is connected to the planetary gears, and an output shaft is provided on the sun gear.

7. A rehabilitation walking assistive exoskeleton, characterized in that, It includes the variable stiffness knee joint according to any one of claims 1 - 6.

8. A control method for a rehabilitation walking assistive exoskeleton, characterized in that, Applied to the rehabilitation walking assist exoskeleton according to claim 7, the control method includes: Obtaining initial data and real - time data. The initial data is the data information of the rotational drive device, the thigh component, and the calf component when the user wears it, and the real - time data is the data information of the rotational drive device, the thigh component, and the calf component when the user walks; According to the initial data and the real - time data, determining the target stage corresponding to the current gait phase of the knee joint, and obtaining the expected stiffness value information of the current target stage; According to the current expected stiffness value information, controlling the rotational drive device to rotate.

9. According to the rehabilitation walking assist exoskeleton control method of claim 8, according to the initial data and the real - time data, determining the target stage corresponding to the current gait phase of the knee joint, and obtaining the expected stiffness value information of the current target stage; includes: The initial data and the real-time data include plantar pressure data information. Based on the plantar pressure data information, it is determined whether the current gait phase of the knee joint is in the stance phase or the swing phase; Based on the initial data and the real-time data, knee joint angle data information and knee joint angular velocity data information are determined; Based on the knee joint angle data, the early stance phase, the mid-stance phase or the late stance phase is determined. Based on the knee joint angular velocity data information, the swing phase extension period or the swing phase flexion period is determined.

10. The rehabilitation-assisted walking exoskeleton control method according to claim 9, controlling the rotation of the rotation drive device according to the current desired stiffness value information, including: Calculating the compression angle information of the rigid spring according to the current desired stiffness value information and the knee joint angle data information; Controlling the rotation of the rotation drive device according to the compression angle information of the rigid spring.

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