Ai knee joint and control method therefor

Abstract

The present invention belongs to the technical field of medical devices. Disclosed is an AI knee joint. A second shaft is arranged on the rear portion of a joint head of the AI knee joint; a slider is hinged to the second shaft, and the slider is provided with a through threaded hole; a third shaft is arranged on the middle portion of a calf support; a motor is hinged to the third shaft; an output shaft of the motor is connected to a lead screw, and the lead screw is in threaded connection with the slider; a toe pressure sensor is arranged on the front side of the calf support, and a heel pressure sensor is arranged on the rear side of the calf support. Provided is a control method for the AI knee joint. A plurality of walking modes are preset for a control module thereof, and the plurality of walking modes comprise a flat ground mode, an up-step mode, a down-step mode, a sitting-down mode, a squatting mode, and a standing-up mode. According to the present invention, the current state is determined by means of motor driving, pressure sensing, and angle detection, and the walking modes are automatically switched, thereby realizing active flexion-extension control and intelligent gait adaptation, and improving the flexibility and stability of the prosthesis and the walking comfort of a user.

Description

An AI-powered knee joint and its control method Technical Field

[0001] This invention belongs to the field of medical device technology, and in particular relates to an AI knee joint and its control method. Background Technology

[0002] Due to traffic accidents, illnesses, and other reasons, the number of people undergoing lower leg amputations is gradually increasing, and ankle prostheses can compensate for lost functions. Research on ankle prostheses began earlier abroad, with early prostheses mostly being passive. Early passive ankle prostheses used wood, but later, due to material advancements, elastic energy storage devices were used to increase the prosthesis's elasticity. Currently, prostheses are generally made of energy storage materials such as rubber and carbon fiber for the footplate. However, compared to abroad, research on prostheses in China started later. Domestic research mainly focuses on achieving the function of knee prostheses, while the ankle joint is only considered as an elastic energy storage structure to assist walking. Some key technologies still need development and improvement to address the pain points of amputees.

[0003] Existing ankle joint connectors for the lower leg are mostly passive, relying on the deformation of the foot itself to meet the rebound force required by the residual limb. This results in relatively rigid, stiff, and inflexible movement. When crawling up and down stairs or walking on slopes, the ankle joint cannot adjust its plantar flexion and dorsiflexion according to the road surface. It basically requires the wearer's residual limb and hip to provide power, making movement difficult and extremely inconvenient. Summary of the Invention

[0004] This invention provides an AI knee joint to solve existing technical problems.

[0005] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0006] An AI knee joint includes a joint head, a lower leg support, and a connector. The top of the joint head is hinged to a thigh component, and the bottom of the joint head is hinged to the lower leg support via a first axis. The top of the connector is connected to the lower leg support, and the bottom of the connector is connected to a foot plate component. A second axis is provided at the rear of the joint head, and a slider is hinged to the second axis. The slider has a through threaded hole. A third axis is provided in the middle of the lower leg support. The first, second, and third axes are coaxially arranged. A motor is hinged to the third axis, and a lead screw is connected to the output shaft of the motor. The lead screw is threadedly connected to the slider.

[0007] The front side of the calf support is provided with a first compression part and a second compression part that are spaced apart vertically. The first compression part and the second compression part can deform and are connected to a toe pressure sensor. When the calf support is under load at the front, the first compression part and the second compression part can move closer to each other to compress the toe pressure sensor.

[0008] The lower leg support is provided with a third compression part and a fourth compression part arranged at intervals. The third compression part and the fourth compression part can deform and are connected to a heel pressure sensor. When the lower leg support is under load at the rear, the third compression part and the fourth compression part can move closer to each other to compress the heel pressure sensor.

[0009] The lower leg support also includes a control module and a battery. The control module is connected to the motor, toe pressure sensor, heel pressure sensor, and battery, respectively.

[0010] As a further improvement to the above technical solution:

[0011] An angle sensor is provided on the lower leg support. The detection axis of the angle sensor is connected to the first axis, and the information output terminal of the angle sensor is connected to the control module.

[0012] The bottom of the joint head is provided with a clearance groove, and the slider and the lead screw extending from the threaded hole can rotate within the clearance groove.

[0013] The first and second compression sections are located near the upper part of the calf support, while the third and fourth compression sections are located near the bottom of the calf support.

[0014] An AI-based knee joint control method includes a control module that collects toe pressure signals from a toe pressure sensor to detect the force applied when the toes of the foot press against the ground, a control module that collects heel pressure signals from a heel pressure sensor to detect the force applied when the heel of the foot presses against the ground, and a control module that collects flexion-extension angle signals from an angle sensor to detect the flexion-extension angle of the knee joint.

[0015] The control module has multiple preset walking modes, including flat ground mode, step-up mode, step-down mode, sitting mode, squatting mode, and standing mode.

[0016] The leg-raising action in the flat ground mode: The wearer shifts the center of gravity forward using the healthy limb, and then only presses the toes of the prosthetic foot onto the ground and maintains the pressing position. The control module collects a continuous toe pressure signal, executes the leg-raising action in the flat ground mode, starts the motor to drive the lead screw to rotate so that the slider is close to the motor, and the knee joint of the prosthesis flexes without supporting the weight. The range of knee flexion is the range of knee flexion required when the human body walks normally.

[0017] The stepping action in the flat ground mode is as follows: when the heel of the foot presses down on the ground and remains in the pressing state, the control module collects a continuous heel pressure signal, executes the stepping action in the flat ground mode, starts the motor to drive the lead screw to rotate in the opposite direction so that the slider moves away from the motor, and the knee joint of the prosthesis extends to an upright position under the load.

[0018] The continuous movements of the flat ground mode are as follows: After the stepping movement in the flat ground mode, the wearer shifts their center of gravity forward and performs the leg lifting movement in the flat ground mode again, repeating this process to complete normal walking on flat ground.

[0019] The leg-lifting action in the step-up mode is as follows: the wearer shifts their center of gravity forward using their healthy limb, then briefly presses the toes of the prosthetic foot onto the ground, then quickly lifts off the ground, and then quickly presses the foot back onto the ground and maintains the pressing position. The control module collects intermittent toe pressure signals, executes the leg-lifting action in the step-up mode, starts the motor to drive the lead screw to rotate so that the slider moves closer to the motor, and the knee joint of the prosthesis flexes without supporting the weight. The degree of knee flexion is the degree of knee flexion required when the human body normally climbs a step.

[0020] The stepping action in the stepping mode is as follows: when the heel and toe of the prosthesis press the ground in sequence and maintain the pressing state, the control module collects the continuous heel pressure signal and toe pressure signal, executes the stepping action in the stepping mode, starts the motor to drive the lead screw to rotate in the opposite direction so that the slider moves away from the motor, and the knee joint of the prosthesis extends to an upright position under the load.

[0021] The continuous movements of the step-up mode are as follows: after the step-up mode, the wearer shifts their weight forward and lifts their leg again, repeating this process until the normal walking up the stairs is completed.

[0022] The leg extension action in the step-down mode is as follows: The wearer shifts their center of gravity forward by bending their healthy limb, extending the prosthesis to the next step. Then, the heel of the prosthesis foot briefly presses against the ground before quickly lifting off, and then quickly pressing against the ground again while maintaining this pressing position. The control module collects intermittent heel pressure signals, executes the leg extension action in the step-down mode, starts the motor to drive the lead screw to rotate so that the slider moves closer to the motor, and the knee joint of the prosthesis flexes under load, with the flexion range being the same as that required for normal step-down. At the same time, the wearer shifts their center of gravity forward and places their healthy limb on the next step.

[0023] The support action of the step-down mode is as follows: the wearer shifts the center of gravity of the body forward and gradually straightens the healthy limb until it is in a state of full weight-bearing support. At the same time, the heel of the prosthetic foot gradually lifts off the ground. The control module collects the heel pressure signal, which gradually weakens. The support action of the step-down mode is executed. The motor is started to drive the lead screw to rotate in the opposite direction so that the slider moves away from the motor. The knee joint of the prosthesis supports the extension of the knee while the weight-bearing gradually decreases. The extension range of the knee is the range of knee joint extension required when the human body normally goes down a step.

[0024] The continuous movements of the step-down mode are as follows: After the supporting movement of the step-down mode, the wearer shifts their center of gravity forward and performs the leg extension movement of the step-down mode again, repeating this process until the normal walking down the steps is completed.

[0025] The sitting action in the sitting mode is as follows: the wearer briefly presses the toes of the prosthetic foot onto the ground, then quickly lifts it off the ground, and then quickly presses the heel back onto the ground, keeping the heel pressed against the ground. The control module collects the brief toe pressure signal and the subsequent continuous heel pressure signal, and executes the sitting action in the sitting mode. The motor is started to drive the lead screw to rotate so that the slider is close to the motor. The knee joint of the prosthesis flexes under the load, and the degree of knee flexion is the degree of knee flexion required when the human body sits normally.

[0026] The sitting-up action is as follows: the wearer simultaneously reduces the pressure on the ground by the toes and heels of the prosthetic foot, and then shifts the body's center of gravity forward, increasing the pressure on the ground. The control module collects the pressure signals of the toes and heels, which gradually increase from near zero to near the maximum preset force value. The sitting-up action is then executed, and the motor is started to drive the lead screw to rotate in the opposite direction so that the slider moves away from the motor. Under the load, the knee joint of the prosthetic extends to an upright position.

[0027] The squatting action in the squatting mode is as follows: the wearer briefly presses the heel of the prosthetic foot onto the ground, then quickly lifts it off the ground, and then quickly presses the toes back onto the ground, keeping the toes pressed against the ground. The control module collects the brief heel pressure signal and the subsequent continuous toe pressure signal, executes the squatting action in the squatting mode, starts the motor to drive the lead screw to rotate so that the slider is close to the motor, and the knee joint of the prosthesis flexes under the load. The degree of knee flexion is the degree of knee flexion required when the human body squats normally.

[0028] The standing-up action in the squatting mode: The wearer gradually shifts their center of gravity to the healthy limb, while simultaneously decreasing and then increasing the pressure of the toes of the prosthetic foot on the ground, and increasing and then decreasing the pressure of the heel on the ground. At the same time, the pressure of the toes and heels of the prosthetic foot on the ground increases. The control module collects the pressure signal of the toes, which gradually increases from near zero to near the maximum preset force value, while the pressure signal of the heel gradually decreases from near the maximum preset force value to near zero. The standing-up action in the sitting mode is then executed. The motor is started, which drives the lead screw to rotate in the opposite direction so that the slider moves away from the motor. Under the load, the knee joint of the prosthesis extends to an upright position.

[0029] The control module is equipped with a confirmation mechanism and preset flexion and extension angles of the prosthetic knee joint in multiple walking modes. The mode confirmation mechanism is as follows: in one walking mode, the control module obtains the actual flexion and extension angle of the prosthetic knee joint based on the flexion and extension angle signal transmitted by the angle sensor, and then compares it with the preset flexion and extension angle to determine whether the corresponding action has been performed, or whether the actual flexion and extension angle is consistent with the preset flexion and extension angle. If they are inconsistent, the corresponding action is restarted.

[0030] The control module is equipped with a speed mechanism, which is as follows: in one walking mode, the control module analyzes the current walking speed of the wearer based on the rate of change of the toe pressure signal and the continuous heel pressure signal, and then adjusts the speed of the motor according to the walking speed so that the speed of the flexion and extension movement of the prosthetic knee joint matches the walking speed.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. Active flexion and extension control: The active flexion and extension of the knee joint is achieved by driving the lead screw and slider through the motor, which improves the flexibility and adaptability of the prosthesis and makes walking more natural.

[0033] 2. Precise gait perception: Equipped with toe and heel pressure sensors, and combined with deformable compression components, it can perceive the weight-bearing status in real time, accurately identify different gaits, and improve the stability and safety of walking.

[0034] 3. Intelligent Angle Adjustment: The angle sensor monitors the flexion and extension state of the knee joint, and the intelligent calculation of the control module ensures that the movement of the prosthesis conforms to the gait requirements of the human body, thus enhancing the intelligence level of the prosthesis.

[0035] 4. Structural optimization design: The avoidance groove avoids the movement interference between the lead screw and the slider, ensuring smooth operation of the mechanism, while improving overall durability and stability.

[0036] 5. Adaptable to multiple walking modes: It can make corresponding adjustments according to the user's walking conditions, such as walking on flat ground, going up and down stairs, sitting down, and standing up, so that the prosthesis can better fit the natural movement needs of the human body.

[0037] Overall, the AI ​​knee joint in this embodiment significantly improves flexibility, intelligence, and comfort compared to traditional passive prostheses, providing amputees with a more natural gait experience and greater mobility. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 is a schematic diagram of the structure of the AI ​​knee joint;

[0040] Figure 2 shows the flexion and extension state of the AI ​​knee joint.

[0041] Figure 3 shows the second diagram of the flexion and extension state of the AI ​​knee joint.

[0042] Figure 4 shows the flexion and extension state of the AI ​​knee joint.

[0043] Legend:

[0044] 1. Joint head; 11. First axis; 12. Second axis; 13. Slider; 2. Lower leg support; 21. Third axis; 22. Motor; 23. Lead screw; 24. First extrusion section; 25. Second extrusion section; 26. Toe pressure sensor; 27. Third extrusion section; 28. Fourth extrusion section; 29. ​​Heel pressure sensor; 3. Connector; 4. Control module; 5. Battery; 6. Angle sensor. Detailed Implementation

[0045] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0046] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art, such as anterior part being on the same side as the anterior part of a limb, and posterior part being on the same side as the posterior part of a limb. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of protection of the invention.

[0047] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0048] Example: As shown in Figures 1-4, the AI ​​knee joint of this example includes a joint head 1, a lower leg support 2, and a connector 3. The top of the joint head 1 is hinged to the thigh component, and the bottom of the joint head 1 is hinged to the lower leg support 2 via a first shaft 11. The top of the connector 3 is connected to the lower leg support 2, and the bottom of the connector 3 is connected to the foot plate component. A second shaft 12 is provided at the rear of the joint head 1, and a slider 13 is hinged to the second shaft 12. A through threaded hole is provided on the slider 13. A third shaft 21 is provided in the middle of the lower leg support 2. The first shaft 11, the second shaft 12, and the third shaft 21 are coaxially arranged. A motor 22 is hinged to the third shaft 21, and a lead screw 23 is connected to the output shaft of the motor 22. The lead screw 23 is threadedly connected to the slider 13.

[0049] The front side of the calf support 2 is provided with a first compression part 24 and a second compression part 25 that are spaced apart vertically. The first compression part 24 and the second compression part 25 can deform and are connected to a toe pressure sensor 26. When the calf support 2 is under load at the front, the first compression part 24 and the second compression part 25 can move closer to each other to compress the toe pressure sensor 26.

[0050] The lower leg support 2 is provided with a third compression part 27 and a fourth compression part 28 arranged at intervals. The third compression part 27 and the fourth compression part 28 can deform and are connected to a heel pressure sensor 29. When the lower leg support 2 is under load at the rear, the third compression part 27 and the fourth compression part 28 can move closer to each other to compress the heel pressure sensor 29.

[0051] The lower leg support 2 also contains a control module 4 and a battery 5. The control module 4 is connected to the motor 22, the toe pressure sensor 26, the heel pressure sensor 29 and the battery 5 respectively.

[0052] This embodiment achieves active flexion and extension of the AI ​​knee joint through the linkage of motor 22, lead screw 23, and slider 13, enabling the prosthesis to dynamically adjust according to the user's walking pattern. Compared to traditional passive prostheses, this embodiment incorporates a toe pressure sensor 26 and a heel pressure sensor 29 on the lower leg support 2. The deformation of the first compression part 24, second compression part 25, third compression part 27, and fourth compression part 28 senses the load-bearing state, allowing the control module 4 to accurately determine gait and adjust the knee joint angle. Furthermore, the addition of the angle sensor 6 allows the control module 4 to detect the flexion and extension state of the knee joint in real time, further improving the adaptability and intelligence of the prosthesis. The clearance groove design at the bottom of the joint head 1 ensures that the movement of the lead screw 23 and slider 13 is not structurally restricted, improving the stability and durability of the mechanism. Overall, compared to traditional passive prostheses, the AI ​​knee joint of this embodiment can more flexibly adapt to different terrains and usage needs, providing amputees with a more natural and comfortable gait experience.

[0053] In this embodiment, an angle sensor 6 is provided on the lower leg support 2. The detection axis of the angle sensor 6 is connected to the first axis 11, and the information output terminal of the angle sensor 6 is connected to the control module 4. It can monitor the rotation angle of the knee joint in real time and transmit the data to the control module 4, so that the control system can accurately perceive the joint movement state, thereby optimizing the drive control of the motor 22, realizing a more natural gait transition, and improving the dynamic adaptability and comfort of the prosthesis.

[0054] In this embodiment, the bottom of the joint head 1 is provided with a clearance groove, and the slider 13 and the lead screw 23 extending out of the threaded hole can rotate in the clearance groove.

[0055] In this embodiment, the first extrusion part 24 and the second extrusion part 25 are located near the upper part of the lower leg support 2, and the third extrusion part 27 and the fourth extrusion part 28 are located near the bottom of the lower leg support 2. The clearance groove allows the slider 13 and the lead screw 23 to rotate freely within it, effectively avoiding structural interference, improving the motion stability of the lead screw 23, ensuring smooth transmission when driven by the motor 22, thereby improving the response speed and reliability of the knee joint.

[0056] In this embodiment, an AI knee joint control method is described. The control module 4 collects the toe pressure signal from the toe pressure sensor 26 to detect the force value when the toe of the foot presses against the ground. The control module 4 also collects the heel pressure signal from the heel pressure sensor 29 to detect the force value when the heel of the foot presses against the ground. The control module 4 further collects the flexion and extension angle signal from the angle sensor 6 to detect the flexion and extension angle of the knee joint.

[0057] The control module 4 has multiple walking modes preset, including flat ground mode, step-up mode, step-down mode, sitting mode, squatting mode, and standing mode.

[0058] In flat ground mode, the wearer shifts their center of gravity forward using their healthy limb, then presses only the toes of the prosthetic foot onto the ground and maintains this pressing position. The control module 4 then collects a continuous toe pressure signal and executes the flat ground mode leg lift. The motor 22 is activated, which drives the lead screw 23 to rotate so that the slider 13 moves closer to the motor 22. The knee joint of the prosthesis flexes without bearing weight, and the range of knee flexion is the range of knee flexion required for normal walking.

[0059] Stepping motion in flat ground mode: When the heel of the foot presses down on the ground and remains in the pressing state, the control module 4 collects a continuous heel pressure signal, executes the stepping motion in flat ground mode, starts the motor 22 to drive the lead screw 23 to rotate in the opposite direction so that the slider 13 moves away from the motor 22, and the knee joint of the prosthesis extends to an upright position under the load.

[0060] Continuous movements in flat ground mode: After stepping in flat ground mode, the wearer shifts their weight forward and performs the leg-lifting movement in flat ground mode again, repeating this process to complete normal walking on flat ground.

[0061] The leg-lifting action in the step-up mode: The wearer shifts the center of gravity forward using the healthy limb, then only briefly presses the toes of the prosthetic foot onto the ground, then quickly lifts off the ground, and then quickly presses back onto the ground and maintains the pressing position. The control module 4 collects intermittent toe pressure signals, executes the leg-lifting action in the step-up mode, starts the motor 22 to drive the lead screw 23 to rotate so that the slider 13 moves closer to the motor 22. The knee joint of the prosthesis flexes without supporting the weight, and the degree of knee flexion is the degree of knee flexion required when the human body normally climbs a step.

[0062] The stepping action in the stepping mode: When the heel and toe of the prosthesis press the ground in sequence and maintain the pressing state, the control module 4 collects the continuous heel pressure signal and toe pressure signal, executes the stepping action in the stepping mode, starts the motor 22 to drive the lead screw 23 to rotate in the opposite direction so that the slider 13 moves away from the motor 22, and the knee joint of the prosthesis extends to the upright state under the load.

[0063] The continuous movements of the stepping motion: After stepping up the stairs, the wearer shifts their weight forward and lifts their leg again, repeating this motion until they complete the normal walking motion up the stairs.

[0064] The leg extension action in the step-down mode: The wearer shifts their center of gravity forward by bending their healthy limb, extending the prosthesis to the next step. Then, the heel of the prosthesis foot briefly presses against the ground, then quickly lifts off the ground, and then quickly presses against the ground again, maintaining the pressed-to-the-ground state. The control module 4 collects intermittent heel pressure signals and executes the leg extension action in the step-down mode. The motor 22 is started, driving the lead screw 23 to rotate so that the slider 13 moves closer to the motor 22. The knee joint of the prosthesis flexes under load, and the degree of knee flexion is the degree of knee flexion required when the human body normally descends a step. At the same time, the wearer shifts their center of gravity forward and places their healthy limb on the next step.

[0065] The support action in the step-down mode: The wearer shifts the center of gravity forward and gradually straightens the healthy limb until it is fully supported. At the same time, the heel of the prosthetic foot gradually lifts off the ground. The control module 4 collects the heel pressure signal, which gradually weakens. The support action in the step-down mode is executed. The motor 22 is started, which drives the lead screw 23 to rotate in the opposite direction so that the slider 13 moves away from the motor 22. The knee joint of the prosthesis supports the extension of the knee as the load gradually decreases. The extension range is the range of knee joint extension required when the human body is normally stepping down.

[0066] The continuous movements of the step-down mode: After the supporting movement of the step-down mode, the wearer shifts their center of gravity forward and performs the leg extension movement of the step-down mode again, repeating this process until the normal walking down the steps is completed.

[0067] The sitting action in the sitting mode: The wearer briefly presses the toes of the prosthetic foot onto the ground, then quickly lifts it off the ground, and then quickly presses the heel onto the ground, keeping the heel pressed against the ground. The control module 4 collects the brief toe pressure signal and the subsequent continuous heel pressure signal, and executes the sitting action in the sitting mode. The motor 22 is started to drive the lead screw 23 to rotate so that the slider 13 moves closer to the motor 22. The knee joint of the prosthesis flexes under the load, and the degree of knee flexion is the degree of knee flexion required when the human body sits normally.

[0068] The sitting-up action: The wearer reduces the pressure on the ground by simultaneously reducing the pressure of the toes and heels of the prosthetic foot, and then shifts the body's center of gravity forward, increasing the pressure on the ground. The control module 4 collects the pressure signals of the toes and heels, which gradually increase from near zero to near the maximum preset force value, and executes the sitting-up action. The motor 22 is started, which drives the lead screw 23 to rotate in the opposite direction so that the slider 13 moves away from the motor 22. Under the load, the knee joint of the prosthesis extends to an upright position.

[0069] Squatting action in squatting mode: The wearer briefly presses the heel of the prosthetic foot onto the ground, then quickly lifts it off the ground, and then quickly presses the toes back onto the ground, keeping the toes pressed against the ground. The control module 4 collects the brief heel pressure signal and the subsequent continuous toe pressure signal, and executes the squatting action in squatting mode. The motor 22 is started to drive the lead screw 23 to rotate so that the slider 13 moves closer to the motor 22. The knee joint of the prosthesis flexes under load, and the degree of knee flexion is the degree of knee flexion required when the human body squats normally.

[0070] The standing up action in squatting mode: The wearer gradually shifts their center of gravity to the healthy limb. At the same time, the pressure of the toes of the prosthetic foot on the ground decreases and then increases, while the pressure of the heel on the ground increases and then decreases. Simultaneously, the pressure of the toes and heels of the prosthetic foot on the ground increases. The control module 4 collects the pressure signal of the toes, which gradually increases from near zero to near the maximum preset force value. At the same time, the pressure signal of the heel gradually decreases from near the maximum preset force value to near zero. The standing up action in sitting mode is executed. The motor 22 is started, which drives the lead screw 23 to rotate in the opposite direction so that the slider 13 moves away from the motor 22. Under the load, the knee joint of the prosthesis extends to an upright position.

[0071] In this embodiment, the control module 4 collects signals from the toe pressure sensor 26, heel pressure sensor 29, and angle sensor 6 to detect the force on the prosthetic foot and the flexion and extension angle of the knee joint in real time, thereby achieving intelligent control in different walking modes. This design can effectively improve the adaptability of the prosthesis, making the wearer's movements more natural and fluid in different scenarios.

[0072] Knee joint angle variation parameters in each mode:

[0073] Flat Ground Mode: Knee flexion angle range: When a person walks normally, the knee joint flexion angle is generally between 0° and 65° (when taking a step); Knee extension angle range: When a person stands, the knee joint is close to 0°, that is, fully extended; Flat Ground Mode is a control mode for various movements in one gait cycle.

[0074] Stair climbing mode: Knee flexion angle range: When a person climbs a stair, the knee joint flexion angle is generally between 70° and 90°, depending on the height of the stair; Knee extension angle range: The knee is extended to 0°, that is, fully straightened, to support the body weight.

[0075] Step-down mode: Knee flexion angle range: When a person goes down a step, the knee flexion angle is generally between 15° and 40°, depending on the stride and descent speed; Knee extension angle range: Usually between 0° and 10°, depending on the walking method; When going down a step, the knee is slowly flexed while in a supporting position.

[0076] Sitting mode: Knee flexion angle range: When a person sits down normally, the knee joint flexion angle is usually between 90° and 120°. Different seat heights may cause changes in the angle; Knee extension angle range: When sitting down, the knees are not extended and remain in a flexed state.

[0077] Standing up mode: Knee flexion angle range: Before standing up, the knee joint is generally at 90°~120°, depending on the sitting posture before standing up; Knee extension angle range: After standing up, the knee joint extends to 0° to complete standing.

[0078] Squatting mode: Knee flexion angle range: When a person squats normally, the knee joint flexion angle is generally between 90° and 150°, and even close to 160° when squatting deeply; Knee extension angle range: When standing up, the knee joint gradually returns from 90° to 150° to the 0° upright position.

[0079] The response mechanism of the intelligent prosthesis: The control module 4 determines the current state based on the signals from the pressure sensor and the angle sensor, and automatically switches the walking mode;

[0080] Precise control: Motor 22 drives lead screw 23, causing slider 13 to move along the lead screw, precisely controlling the bending and extension of the knee joint;

[0081] Dynamic adaptation: In different modes, the knee flexion and extension angles conform to the natural movement needs of the human body, making the wearer's movement more stable and closer to a normal walking posture; the center of gravity shifts from the heel to the ball of the foot, and the knee flexion begins according to the actual situation.

[0082] This design can effectively improve the comfort and adaptability of prosthesis wearers in different terrains and with different movements, and enhance the safety and naturalness of walking.

[0083] In this embodiment, the control module 4 is equipped with a confirmation mechanism and preset flexion-extension angles of the prosthetic knee joint in multiple walking modes. The mode confirmation mechanism works as follows: In one walking mode, the control module 4 obtains the actual flexion-extension angle of the prosthetic knee joint based on the flexion-extension angle signal transmitted from the angle sensor 6, and then compares it with the preset flexion-extension angle to determine whether the corresponding action has been performed, or whether the actual flexion-extension angle is consistent with the preset flexion-extension angle. If they are inconsistent, the corresponding action is restarted. This effectively improves the precise control and responsiveness of the prosthetic knee joint. The confirmation mechanism monitors the flexion-extension angle of the prosthetic knee joint in real time through feedback from the angle sensor 6 and compares it with the preset angle to determine whether the predetermined action has been performed, avoiding problems such as inaccurate or abnormal prosthetic movement, and ensuring the wearer's gait is stable and natural.

[0084] In this embodiment, the control module 4 is equipped with a speed mechanism. This mechanism works as follows: In one walking mode, the control module 4 analyzes the wearer's current walking speed based on the rate of change of the toe pressure signal and the continuous heel pressure signal. Then, it adjusts the rotation speed of the motor 22 according to the walking speed to match the speed of the prosthetic knee joint's flexion and extension movements with the walking speed. This highly matches the flexion and extension movements of the prosthetic knee joint with the walking speed, providing a more comfortable and efficient walking experience. It effectively solves the problem of poor adaptability of traditional prosthetic knee joints under different gait states and avoids sudden or excessively slow movements when the prosthesis touches the ground. If the movement is too fast upon contact with the ground, the system will automatically adjust to prevent unnatural and violent reactions from the prosthesis; if the movement is too slow, the system will increase the motor speed to ensure smooth and timely response of the prosthesis's movement. In this way, the control module 4 ensures that the movement of the prosthesis is more stable and natural, improving the wearer's comfort and safety.

Claims

1. An AI knee joint comprising a joint head (1), a lower leg support (2) and a connecting piece (3), the top of the joint head (1) being connected to a thigh piece, the bottom of the joint head (1) being hingedly connected to the lower leg support (2) via a first shaft (11), the top of the connecting piece (3) being connected to the lower leg support (2), and the bottom of the connecting piece (3) being connected to a foot plate piece, characterized in that, The joint head (1) is provided with a second shaft (12) in the rear part, the second shaft (12) is hinged with a sliding block (13), the sliding block (13) is provided with a threaded hole penetrating through, the middle part of the lower leg support (2) is provided with a third shaft (21), the first shaft (11), the second shaft (12) and the third shaft (21) are coaxially arranged, the third shaft (21) is hinged with a motor (22), the output shaft of the motor (22) is connected with a lead screw (23), the lead screw (23) is threadedly connected with the sliding block (13); The front side of the lower leg support (2) is provided with a first extrusion part (24) and a second extrusion part (25) arranged in an upper and lower interval, the first extrusion part (24) and the second extrusion part (25) can be deformed, and the toe pressure sensor (26) is connected between the first extrusion part (24) and the second extrusion part (25), the lower leg support (2) can make the first extrusion part (24) and the second extrusion part (25) close to each other when the front part is under load, so as to extrude the toe pressure sensor (26); The rear side of the lower leg support (2) is provided with a third extrusion part (27) and a fourth extrusion part (28) arranged in an upper and lower interval, the third extrusion part (27) and the fourth extrusion part (28) can be deformed, and the heel pressure sensor (29) is connected between the third extrusion part (27) and the fourth extrusion part (28), the lower leg support (2) can make the third extrusion part (27) and the fourth extrusion part (28) close to each other when the rear part is under load, so as to extrude the heel pressure sensor (29); The lower leg support (2) is further provided with a control module (4) and a battery (5), the control module (4) is connected with the motor (22), the toe pressure sensor (26), the heel pressure sensor (29) and the battery (5) respectively.

2. The AI knee joint of claim 1, wherein, The lower leg support (2) is provided with an angle sensor (6), the detection shaft of the angle sensor (6) is connected with the first shaft (11), and the information output end of the angle sensor (6) is connected with the control module (4).

3. The AI knee joint of claim 1, wherein, The bottom of the joint head (1) is provided with an avoiding groove, and the sliding block (13) and the lead screw (23) extending out of the threaded hole can rotate in the avoiding groove.

4. The AI knee according to claim 1, characterized in that, The first extrusion part (24) and the second extrusion part (25) are close to the upper part of the lower leg support (2), and the third extrusion part (27) and the fourth extrusion part (28) are close to the bottom of the lower leg support (2).

5. The control method of an AI knee joint according to any one of claims 2-4, characterized in that, The control module (4) collects the toe pressure signal of the toe pressure sensor (26), which is used for detecting the stress value when the foot plate presses the ground at the toe, the control module (4) collects the heel pressure signal of the heel pressure sensor (29), which is used for detecting the stress value when the foot plate presses the ground at the heel, and the control module (4) collects the flexion and extension angle signal of the angle sensor (6), which is used for detecting the flexion and extension angle of the knee joint; The control module (4) is preset with multiple walking modes, and the multiple walking modes include flat ground mode, up stairs mode, down stairs mode, sitting mode, squatting mode and standing up mode; The leg lifting action of the flat ground mode: the wearer moves the body center of gravity forward by the healthy limb, then only the tip of the prosthetic foot plate presses the ground, and keeps the state of pressing the ground, then the control module (4) collects the continuous tip pressure signal, executes the leg lifting action of the flat ground mode, starts the motor (22) to drive the screw rod (23) to rotate to make the sliding block (13) close to the motor (22), the knee joint of the prosthesis is bent without supporting the weight, and the bending amplitude is the bending amplitude of the knee joint required when the human body normally walks; The stepping action of the flat ground mode: when the heel of the foot plate presses the ground and keeps the state of pressing the ground, the control module (4) collects the continuous heel pressure signal, executes the stepping action of the flat ground mode, starts the motor (22) to drive the screw rod (23) to reversely rotate to make the sliding block (13) away from the motor (22), the knee joint of the prosthesis is stretched to the upright state under the weight; The continuous action of the flat ground mode: after the stepping action of the flat ground mode, the wearer moves the center of gravity forward again, executes the leg lifting action of the flat ground mode again, and reciprocates in turn to complete the normal walking on the flat ground; The leg lifting action of the step climbing mode: the wearer moves the body center of gravity forward by the healthy limb, then only the tip of the prosthetic foot plate briefly presses the ground, then quickly leaves the ground, then quickly presses the ground again, and keeps the state of pressing the ground, then the control module (4) collects the intermittent tip pressure signal, executes the leg lifting action of the step climbing mode, starts the motor (22) to drive the screw rod (23) to rotate to make the sliding block (13) close to the motor (22), the knee joint of the prosthesis is bent without supporting the weight, and the bending amplitude is the bending amplitude of the knee joint required when the human body normally climbs steps; The stepping action of the step climbing mode: when the heel and the tip of the foot plate of the prosthesis press the ground in turn and keep the state of pressing the ground, the control module (4) collects the continuous heel pressure signal and the tip pressure signal, executes the stepping action of the step climbing mode, starts the motor (22) to drive the screw rod (13) to reversely rotate to make the sliding block (13) away from the motor (22); the knee joint of the prosthesis is stretched to the upright state under the weight; The stepping action of the step climbing mode: after the stepping action of the flat ground mode, the wearer moves the center of gravity again, executes the leg lifting action of the step climbing mode again, and reciprocates in turn until the normal walking on the steps is completed; The leg lifting action of the step climbing mode: the wearer moves the body center of gravity by bending the healthy limb, stretches the prosthesis to the next step, then only the heel of the prosthetic foot plate briefly presses the ground, then quickly leaves the ground, then quickly press the ground again, and keep the state of pressing the ground, then the control module (4) collects the intermittent heel pressure signal, executes the leg lifting action of the step climbing mode, starts the motor (22), drives the screw rod (23) to rotate to make the sliding block (13) close to the electric motor (22), the knee joint of the prosthesis is bent under the weight, and the bending amplitude is the bending amplitude of the knee joint required when the human being normally descends the steps; simultaneously, the body center of gravity is moved forward, and the healthy limb is stepped on the next step. The support action of the down-step mode: the wearer moves the body center of gravity forward, gradually straightens the healthy limb, until the full weight-bearing support state, at the same time, the heel of the prosthetic foot plate gradually leaves the ground, then the control module (4) collects the gradually weakened heel pressure signal, executes the support action of the down-step mode, starts the motor (22) to drive the screw rod (23) to reverse rotation to make the sliding block (13) away from the motor (22), the knee joint of the prosthesis supports the extension of the knee under the condition of gradually decreasing weight-bearing, and the amplitude of the extension of the knee is the amplitude required for the knee joint when the human body normally steps down; The continuous action of the down-step mode: after the support action of the down-step mode, the wearer moves the center of gravity forward again, executes the leg extension action of the down-step mode again, and reciprocates in turn until the normal walking of the down-step is completed; The sitting action of the sitting mode: the wearer makes the toe of the prosthetic foot plate press the ground temporarily, then quickly leaves the ground, and then makes the heel quickly press the ground, so that the heel keeps pressing the ground, then the control module (4) collects the temporary toe pressure signal and the subsequent continuous heel pressure signal, executes the sitting action of the sitting mode, starts the motor (22) to drive the screw rod (23) to rotate to make the sliding block (13) close to the motor (22), the knee joint of the prosthesis flexes under the weight, and the amplitude of the flexion of the knee is the amplitude required for the knee joint when the human body normally sits down; The standing action of the sitting mode: the wearer simultaneously reduces the pressure of the toe and the heel of the prosthetic foot plate on the ground, then moves the body center of gravity forward, and simultaneously increases the pressure on the ground, then the control module (4) collects the toe pressure signal and the heel pressure signal from close to zero to gradually increase to close to the maximum preset force value, executes the standing action of the sitting mode, starts the motor (22) to drive the screw rod (23), so that the sliding block (13) is away from the motor (22), the knee joint of the prosthesis extends to the upright state under the weight; The squatting action of the squatting mode: the wearer makes the heel of the prosthetic foot plate press the ground temporarily, then quickly leaves the ground, and then the toe quickly presses the ground, so that the toe keeps pressing the ground, then the control module (4) collects the temporary heel pressure signal and the subsequent continuous toe pressure signal, executes the squatting action of the squatting mode, starts the motor (22) to drive the screw rod (23) to rotate to enable the sliding block (13) to be close to the motor (22), the knee joint of the prosthesis flexes under the load, and the amplitude of the flexion of the knee is the amplitude required for the knee joint to bend when the human body normally squats; The standing action of the squatting mode: the wearer gradually moves the body center of gravity to the healthy limb, simultaneously reduces and then increases the pressure of the toe of the prosthetic foot plate on the ground, simultaneously increases and then reduces the pressure of the heel on the ground, simultaneously increases the pressure of the toe and the heel of the prosthetic foot plate on the ground, then the control module (4) collects the toe pressure signal from close to zero to gradually increase to close to the maximum preset force value, and simultaneously collects the heel pressure signal from close to the maximum preset force value to gradually decrease to close to zero, executes the standing action of the sitting mode, starts the motor (22) to drive the reverse rotation of the screw rod (23) to make the sliding block (13) away from the motor (22), and the knee joint of the prosthesis extends to the upright state under the weight. 6.The control method of an AI knee joint according to claim 5, characterized in that, The control module (4) is provided with a confirmation mechanism and preset flexion and extension angles of the prosthetic knee joint in multiple walking modes, the mode confirmation mechanism is that in one of the walking modes, the control module (4) obtains the actual flexion and extension angle of the prosthetic knee joint according to the flexion and extension angle signal transmitted by the angle sensor (6), and then compares the preset flexion and extension angle to determine whether the corresponding action is performed or whether the actual flexion and extension angle is consistent with the preset flexion and extension angle, and if not, the corresponding action is restarted. 7.The control method of an AI knee joint according to claim 6, characterized in that, The control module (4) is provided with a speed mechanism, the speed mechanism is that in one of the walking modes, the control module (4) analyzes the walking speed of the current wearer according to the change rate of the toe pressure signal and the sustained heel pressure signal, and then adjusts the rotating speed of the motor (22) according to the walking speed, so that the flexion and extension speed of the prosthetic knee joint matches the walking speed.

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