AI knee joint and control method thereof

Abstract

The invention belongs to the technical field of medical instruments, and discloses an AI knee joint which is characterized in that a second shaft is arranged on the rear portion of a joint head of the AI knee joint, a sliding block is hinged to the second shaft, a through threaded hole is formed in the sliding block, a third shaft is arranged in the middle of a shank support, a motor is hinged to the third shaft, an output shaft of the motor is connected with a lead screw, and the lead screw is in threaded connection with the sliding block; a toe pressure sensor is arranged on the front side of the shank support, and a heel pressure sensor is arranged on the rear side of the shank support. According to the AI knee joint control method, a plurality of walking modes are preset in a control module and comprise a flat ground mode, an upstep mode, a downstep mode, a sitting mode, a squatting mode and a getting-up mode. Through motor driving, pressure sensing and angle detection, the current state is judged, the walking mode is automatically switched, active flexion and extension control and intelligent gait adaptation are achieved, and the flexibility and stability of the artificial limb and the walking comfort of a user are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and particularly relates to an AI knee joint and a control method thereof. Background Art

[0002] Due to reasons such as traffic accidents and diseases, the number of people with lower leg amputations is gradually increasing, and wearing an ankle prosthesis can achieve compensation for the missing functions of the human body. The research on ankle prostheses started earlier abroad. Most of the early prostheses were passive ankle prostheses. In the early days, passive ankle prostheses were made of wooden prostheses. Later, due to material changes, elastic energy storage devices were mostly used to increase the elastic performance of the prostheses. Now, the general prosthetic material uses energy storage materials such as rubber and carbon fiber to make the foot plate. However, compared with abroad, the research on prostheses in China started relatively late. Domestic research mainly focuses on the realization of the functions of knee prostheses, while the ankle joint is only regarded as an elastic energy storage structure to assist human walking. Some key technologies still need to be developed and improved to solve the pain points of amputee patients.

[0003] Most of the existing lower leg connecting piece ankle joints are passive, using the deformation amount of the foot plate itself to meet the resilience required by the residual limb. The movement is relatively rigid, inflexible, and has poor flexibility. For climbing up and down stairs and walking on slopes, the ankle joint cannot perform plantar flexion and dorsiflexion changes according to the road conditions. Basically, the body swing of the amputee's stump and hip is required to provide power, making the movement strenuous and extremely inconvenient. Summary of the Invention

[0004] The present invention provides an AI knee joint to solve the existing technical problems.

[0005] To solve the above technical problems, the technical solution proposed by the present invention is as follows: An AI knee joint includes a joint head, a lower leg bracket, and a connecting piece. The top of the joint head is connected to the thigh piece. The bottom of the joint head is hinged to the lower leg bracket through a first shaft. The top of the connecting piece is connected to the lower leg bracket, and the bottom of the connecting piece is connected to the foot plate piece. A second shaft is provided at the rear of the joint head, and a slider is hinged to the second shaft. A threaded hole runs through the slider. A third shaft is provided in the middle of the lower leg bracket. The first shaft, the second shaft, and the third shaft are coaxially arranged. A motor is hinged to the third shaft, and an output shaft of the motor is connected to a lead screw, and the lead screw is threadedly connected to the slider; A first extrusion part and a second extrusion part are arranged at intervals up and down on the front side of the lower leg bracket. The first extrusion part and the second extrusion part can deform, and a toe pressure sensor is connected between them. When the front part of the lower leg bracket bears weight, the first extrusion part and the second extrusion part can approach each other to squeeze the toe pressure sensor; The rear side of the calf support is provided with a third pressing part and a fourth pressing part spaced apart from each other, the third pressing part and the fourth pressing part can be deformed, and a heel pressure sensor is connected therebetween, and the calf support can make the third pressing part and the fourth pressing part approach each other when the rear part bears weight to press the heel pressure sensor; A control module and a battery are also provided in the calf support, and the control module is connected to the motor, the toe pressure sensor, the heel pressure sensor and the battery respectively.

[0006] As a further improvement of the above technical solution: The calf support is provided with an angle sensor, a detection axis of the angle sensor is connected to the first axis, and an information output end of the angle sensor is connected to the control module.

[0007] An avoidance groove is arranged at the bottom of the joint head, and the sliding block and the screw rod extending out of the threaded hole can rotate in the avoidance groove.

[0008] The first extrusion portion and the second extrusion portion are close to the upper portion of the calf support, and the third extrusion portion and the fourth extrusion portion are close to the bottom portion of the calf support.

[0009] A control method for an AI knee joint, wherein the control module collects a toe pressure signal from a toe pressure sensor to detect the force value when the toe of the foot presses the ground, the control module collects a heel pressure signal from a heel pressure sensor to detect the force value when the heel of the foot presses the ground, and the control module collects a flexion and extension angle signal from an angle sensor to detect the flexion and extension angle of the knee joint; The control module is preset with a plurality of walking modes, wherein the plurality of walking modes include a flat ground mode, a stair climbing mode, a stair descending mode, a sitting mode, a squatting mode and a standing up mode; The leg-lifting action in the flat-ground mode: the wearer moves the center of gravity of the human body forward through the healthy limb, and then only presses the toe of the prosthetic foot plate on the ground and keeps pressing the ground. The control module collects the continuous toe pressure signal, executes the leg-lifting action in the flat-ground mode, starts the motor to drive the screw rod to rotate so that the slider is close to the motor, and the knee joint of the prosthetic limb is bent without supporting the weight, and the range of knee flexion is the range of knee joint bending required for normal walking of the human body; The stepping action in the flat ground mode: when the heel of the foot presses the ground and keeps pressing the ground, the control module collects a continuous heel pressure signal, executes the stepping action in the flat ground mode, starts the motor to drive the screw rod to rotate in the opposite direction to move the slider away from the motor, and the knee joint of the prosthesis is extended to an upright state under load; Continuous action in the flat ground mode: after the stepping action in the flat ground mode, the wearer moves the center of gravity forward and performs the leg lifting action in the flat ground mode again, repeating the steps one after another to complete normal walking on the flat ground; The leg-lifting action in the stair-climbing mode: the wearer moves the center of gravity of the human body forward through the healthy limb, and then only presses the ground with the toe of the prosthetic foot briefly, and then quickly leaves the ground, and then quickly presses the ground again, and keeps pressing the ground. The control module collects intermittent toe pressure signals, executes the leg-lifting action in the stair-climbing mode, starts the motor to drive the screw rod to rotate so that the slider is close to the motor, and the knee joint of the prosthesis is bent without supporting the weight, and the range of knee flexion is the range of knee joint bending required when the human body normally climbs stairs; The stepping action of the stair-climbing mode: when the heel and toe of the prosthesis press the ground in turn and keep pressing the ground, the control module collects continuous heel pressure signals and toe pressure signals, executes the stepping action of the stair-climbing mode, starts the motor to drive the screw rod to rotate in the opposite direction to move the slider away from the motor, and the knee joint of the prosthesis is extended to an upright state under load; The continuous action of the stair climbing mode: after the stepping action in the stair climbing mode, the wearer moves the center of gravity forward and performs the leg lifting action in the stair climbing mode again, repeating the steps in sequence until the normal walking on the stairs is completed; The leg extension action in the step-down mode: the wearer bends the healthy limb to move the body's center of gravity forward, extends the prosthesis to the next step, and then only briefly presses the ground with the heel of the prosthesis foot, then quickly leaves the ground, and then quickly presses the ground again, and keeps pressing the ground. The control module collects intermittent heel pressure signals, executes the leg extension action in the step-down mode, starts the motor to drive the screw rod to rotate so that the slider approaches the motor, and the knee joint of the prosthesis bends under load, and the range of knee flexion is the range of knee joint bending required when the human body normally goes down the stairs; at the same time, the body's center of gravity is moved forward, and the healthy limb is stepped onto the next step; The support action of the step-down mode: the wearer moves the center of gravity of the human body forward and gradually straightens the healthy limb until it is in a fully load-bearing support state. At the same time, the heel of the prosthetic foot gradually leaves the ground, and the control module collects a gradually weakening heel pressure signal, executes the support action of the step-down mode, starts the motor to drive the screw rod to rotate in the opposite direction to move the slider away from the motor, and the knee joint of the prosthesis supports the knee extension under the condition of gradually decreasing load, and the range of knee extension is the range of knee joint extension required when the human body normally steps down the stairs; Continuous action of the step-down mode: After the supporting action of the step-down mode, the wearer moves the center of gravity forward and performs the leg extension action of the step-down mode again, and repeats the process until the normal walking of the step-down mode is completed; The sitting-down motion of the sitting-down mode: The wearer briefly presses the toe of the prosthetic footplate against the ground, then quickly lifts it off the ground, and then quickly presses the heel against the ground and keeps the heel pressing against the ground. Then the control module collects a brief toe pressure signal and a subsequent continuous heel pressure signal, executes the sitting-down motion of the sitting-down mode, activates the motor to drive the screw rod to rotate so that the slider approaches the motor, and the knee joint of the prosthesis bends under load, and the bending amplitude is the amplitude of knee joint bending required for normal sitting of the human body; The standing-up motion of the sitting-down mode: The wearer simultaneously reduces the pressure of the toe and the heel of the prosthetic footplate on the ground, then shifts the center of gravity of the human body forward and simultaneously increases the pressure on the ground. Then the control module collects the toe pressure signal and the heel pressure signal gradually increasing from near zero to near the maximum preset force value, executes the standing-up motion of the sitting-down mode, activates the motor to drive the screw rod to rotate in the reverse direction so that the slider moves away from the motor, and the knee joint of the prosthesis extends to the upright state under load; The squatting-down motion of the squatting-down mode: The wearer briefly presses the heel of the prosthetic footplate against the ground, then quickly lifts it off the ground, and then quickly presses the toe against the ground and keeps the toe pressing against the ground. Then the control module collects a brief heel pressure signal and a subsequent continuous toe pressure signal, executes the squatting-down motion of the squatting-down mode, activates the motor to drive the screw rod to rotate so that the slider approaches the motor, and the knee joint of the prosthesis bends under load, and the bending amplitude is the amplitude of knee joint bending required for normal squatting of the human body; The standing-up motion of the squatting-down mode: The wearer gradually shifts the center of gravity of the human body to the healthy limb. At the same time, the wearer reduces and then increases the pressure of the toe of the prosthetic footplate on the ground, increases and then reduces the pressure of the heel on the ground, and at the same time, increases the pressure of the toe and the heel of the prosthetic footplate on the ground. Then the control module collects the toe pressure signal gradually increasing from near zero to near the maximum preset force value, and at the same time, the heel pressure signal gradually decreases from near the maximum preset force value to near zero, executes the standing-up motion of the sitting-down mode, activates the motor to drive the screw rod to rotate in the reverse direction so that the slider moves away from the motor, and the knee joint of the prosthesis extends to the upright state under load.

[0010] The control module is provided with a confirmation mechanism and preset flexion and extension angles of the knee joint of the prosthesis in multiple walking modes. The mode confirmation mechanism is as follows: In one of the walking modes, the control module obtains the actual flexion and extension angle of the knee joint of the prosthesis according to the flexion and extension angle signal transmitted by the angle sensor, then compares it with the preset flexion and extension angle, judges whether the corresponding action has been executed, or whether the actual flexion and extension angle is consistent with the preset flexion and extension angle. If not, the corresponding action is restarted.

[0011] The control module is provided with a speed mechanism, which is: in one of the walking modes, the control module analyzes the current wearer's walking speed 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 based on the walking speed so that the speed of the flexion and extension movement of the prosthetic knee joint matches the walking speed.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. Active flexion and extension control: The motor drives the lead screw and the slider to realize active flexion and extension of the knee joint, improving the flexibility and adaptability of the prosthesis and making walking more natural.

[0013] 2. Accurate gait perception: Toe and heel pressure sensors are set up and combined with deformable extrusion components to sense the load-bearing status in real time, accurately identify different gaits, and improve walking stability and safety.

[0014] 3. Intelligent angle adjustment: The angle sensor monitors the flexion and extension of the knee joint, and cooperates with the intelligent calculation of the control module to ensure that the prosthetic movement meets the gait requirements of the human body and enhance the intelligence level of the prosthesis.

[0015] 4. Structural optimization design: The setting of the avoidance groove avoids the movement interference between the screw rod and the slider, ensuring the smooth operation of the mechanism while improving the overall durability and stability.

[0016] 5. Adapt to various 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, standing up, etc., so that the prosthesis can better fit the natural movement needs of the human body.

[0017] Overall, the AI ​​knee joint of this embodiment has significant improvements in flexibility, intelligence, and comfort compared to traditional passive prostheses, providing amputees with a more natural gait experience and greater convenience of movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 This is a schematic diagram of the structure of the AI ​​knee joint; Figure 2 Is the flexion and extension state of the AI ​​knee joint Figure 1 .

[0020] Figure 3 Is the flexion and extension state of the AI ​​knee jointFigure 2 。

[0021] Figure 4 is the flexion and extension state of the AI knee joint Figure 3 。

[0022] Legend: 1. Joint head; 11. First axis; 12. Second axis; 13. Slide block; 2. Calf bracket; 21. Third axis; 22. Motor; 23. Lead screw; 24. First extrusion part; 25. Second extrusion part; 26. Toe pressure sensor; 27. Third extrusion part; 28. Fourth extrusion part; 29. Heel pressure sensor; 3. Connector; 4. Control module; 5. Battery; 6. Angle sensor. Detailed implementation mode

[0023] For the convenience of understanding the present invention, the following will describe the present invention more comprehensively and meticulously in combination with the specification drawings and preferred embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0024] Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly understood by those skilled in the art. For example, the front part and the front part of the limb are on the same side, and the rear part and the rear part of the limb are on the same side. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention.

[0025] Unless otherwise specifically stated, various raw materials, reagents, instruments and equipment used in the present invention can be obtained through the market or can be prepared by existing methods.

[0026] Embodiment: As Figures 1 - 4 shown, the AI knee joint of this embodiment includes a joint head 1, a calf bracket 2 and a connector 3. The top of the joint head 1 is connected to the thigh part, the bottom of the joint head 1 is hinged to the calf bracket 2 through a first axis 11, the top of the connector 3 is connected to the calf bracket 2, the bottom of the connector 3 is connected to the foot plate part, a second axis 12 is provided at the rear of the joint head 1, a slide block 13 is hinged to the second axis 12, a through threaded hole is provided on the slide block 13, a third axis 21 is provided in the middle of the calf bracket 2, the first axis 11, the second axis 12 and the third axis 21 are coaxially arranged, a motor 22 is hinged to the third axis 21, an output shaft of the motor 22 is connected to a lead screw 23, and the lead screw 23 is threadedly connected to the slide block 13; The front side of the calf bracket 2 is provided with a first extrusion part 24 and a second extrusion part 25 arranged at intervals up and down. The first extrusion part 24 and the second extrusion part 25 can be deformed, and a toe pressure sensor 26 is connected between them. When the calf bracket 2 bears weight and force at the front part, the first extrusion part 24 and the second extrusion part 25 can be close to each other to squeeze the toe pressure sensor 26; On the rear side of the calf support 2, there are a third extrusion part 27 and a fourth extrusion part 28 arranged at intervals up and down. The third extrusion part 27 and the fourth extrusion part 28 can deform, and a heel pressure sensor 29 is connected between them. When the rear part of the calf support 2 bears weight, the third extrusion part 27 and the fourth extrusion part 28 can approach each other to squeeze the heel pressure sensor 29. The calf support 2 also is provided with a control module 4 and a battery 5 inside. The control module 4 is respectively connected to the motor 22, the toe pressure sensor 26, the heel pressure sensor 29 and the battery 5.

[0027] In this embodiment, through the linkage of the motor 22, the lead screw 23 and the slider 13, the active flexion and extension function of the AI knee joint is realized, enabling the prosthetic limb to be dynamically adjusted according to the walking pattern of the user. Compared with traditional passive prosthetic limbs, in this embodiment, a toe pressure sensor 26 and a heel pressure sensor 29 are arranged on the calf support 2, and the bearing state is sensed through the deformation of the first extrusion part 24, the second extrusion part 25, the third extrusion part 27 and the fourth extrusion part 28, so that the control module 4 can accurately judge the gait and adjust the knee joint angle. In addition, the addition of the angle sensor 6 enables the control module 4 to detect the flexion and extension state of the knee joint in real time, further improving the adaptability and intelligence level of the prosthetic limb. The design of the avoidance groove at the bottom of the joint head 1 ensures that the movement of the lead screw 23 and the slider 13 will not be restricted by the structure, improving the stability and durability of the mechanism. Generally speaking, compared with traditional passive prosthetic limbs, the AI knee joint of this embodiment can more flexibly adapt to different terrains and usage requirements, providing a more natural and comfortable gait experience for amputees.

[0028] In this embodiment, an angle sensor 6 is arranged on the calf support 2. The detection axis of the angle sensor 6 is connected to the first axis 11, and the information output end 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, enabling the control system to accurately sense the joint movement state, thereby optimizing the drive control of the motor 22, realizing a more natural gait transition, and enhancing the dynamic adaptability and usage comfort of the prosthetic limb.

[0029] In this embodiment, an avoidance groove is arranged at the bottom of the joint head 1. The slider 13 and the lead screw 23 extending out of the threaded hole can rotate in the avoidance groove.

[0030] In this embodiment, the first extrusion part 24 and the second extrusion part 25 are close to the upper part of the calf support 2, and the third extrusion part 27 and the fourth extrusion part 28 are close to the bottom of the calf support 2. The setting of the avoidance groove enables the slider 13 and the lead screw 23 to rotate freely therein, effectively avoiding structural interference, improving the movement stability of the lead screw 23, ensuring smooth transmission when the motor 22 drives, and thus enhancing the response speed and reliability of the knee joint.

[0031] In this embodiment, a control method for an AI knee joint. The control module 4 collects the toe pressure signal of the toe pressure sensor 26 to detect the force value when the toe of the foot plate presses on the ground, collects the heel pressure signal of the heel pressure sensor 29 to detect the force value when the heel of the foot plate presses on the ground, and collects the flexion and extension angle signal of the angle sensor 6 to detect 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 a flat ground mode, a stepping-up mode, a stepping-down mode, a sitting-down mode, a squatting-down mode, and a standing-up mode; Lifting action in the flat ground mode: The wearer shifts the center of gravity of the body forward through the healthy limb, then only makes the toe of the prosthetic foot plate press on the ground and maintains the state of pressing on the ground. Then the control module 4 collects a continuous toe pressure signal and executes the lifting action in the flat ground mode, starting the motor 22 to drive the lead screw 23 to rotate so that the slider 13 approaches the motor 22. The knee joint of the prosthesis bends without supporting the weight, and the bending amplitude is the amplitude required for the knee joint during normal human walking; Stepping action in the flat ground mode: When the heel of the foot plate presses on the ground and maintains the state of pressing on the ground, the control module 4 collects a continuous heel pressure signal and executes the stepping action in the flat ground mode, starting the motor 22 to drive the lead screw 23 to rotate in the reverse direction so that the slider 13 moves away from the motor 22. The knee joint of the prosthesis extends to the upright state under load; Continuous action in the flat ground mode: After the stepping action in the flat ground mode, the wearer then shifts the center of gravity forward again and executes the lifting action in the flat ground mode again, repeating in turn to complete normal walking on the flat ground; Lifting action in the stepping-up mode: The wearer shifts the center of gravity of the body forward through the healthy limb, then only makes the toe of the prosthetic foot plate briefly press on the ground, then quickly leaves the ground, and then quickly presses on the ground again and maintains the state of pressing on the ground. Then the control module 4 collects an intermittent toe pressure signal and executes the lifting action in the stepping-up mode, starting the motor 22 to drive the lead screw 23 to rotate so that the slider 13 approaches the motor 22. The knee joint of the prosthesis bends without supporting the weight, and the bending amplitude is the amplitude required for the knee joint during normal stepping up; Stepping action in the stepping-up mode: When the heel and toe of the prosthetic foot plate press on the ground in sequence and maintain the state of pressing on the ground, the control module 4 collects a continuous heel pressure signal and toe pressure signal and executes the stepping action in the stepping-up mode, starting the motor 22 to drive the lead screw 23 to rotate in the reverse direction so that the slider 13 moves away from the motor 22. The knee joint of the prosthesis extends to the upright state under load; Continuous action in the stepping-up mode: After the stepping action in the stepping-up mode, the wearer then shifts the center of gravity forward again and executes the lifting action in the stepping-up mode again, repeating in turn until normal walking up the steps is completed; Leg extension movement in the descending step mode: The wearer shifts the center of gravity of the body forward by bending the healthy leg, extends the prosthetic leg to the next lower step, then briefly presses the heel of the prosthetic foot sole against the ground, quickly lifts it off the ground, then quickly presses it against the ground again and maintains the state of pressing against the ground. Then the control module 4 collects intermittent heel pressure signals, executes the leg extension movement in the descending step mode, starts the motor 22 to drive the lead screw 23 to rotate so that the slider 13 approaches the motor 22, and the knee joint of the prosthetic leg bends under load, and the bending amplitude is the amplitude required for the knee joint to bend during normal descending steps of the human body; at the same time, shift the center of gravity of the body forward and step the healthy leg on the next lower step. Support movement in the descending step mode: The wearer shifts the center of gravity of the body forward and gradually straightens the healthy leg until it reaches the fully loaded support state. At the same time, the heel of the prosthetic foot sole gradually lifts off the ground. Then the control module 4 collects that the heel pressure signal gradually weakens, executes the support movement in the descending step mode, starts the motor 22 to drive the lead screw 23 to rotate in the reverse direction so that the slider 13 moves away from the motor 22, and the knee joint of the prosthetic leg supports and extends the knee under the condition of gradually decreasing load, and the extension amplitude is the amplitude required for the knee joint to extend during normal descending steps of the human body. Continuous movement in the descending step mode: After the support movement in the descending step mode, the wearer then shifts the center of gravity forward again and executes the leg extension movement in the descending step mode again, repeating in turn until the normal walking of descending the step is completed. Sitting-down movement in the sitting-down mode: The wearer briefly presses the toe of the prosthetic foot sole against the ground, then quickly lifts it off the ground, and then quickly presses the heel against the ground and keeps the heel pressing against the ground. Then the control module 4 collects a brief toe pressure signal and a subsequent continuous heel pressure signal, executes the sitting-down movement in the sitting-down mode, starts the motor 22 to drive the lead screw 23 to rotate so that the slider 13 approaches the motor 22, and the knee joint of the prosthetic leg bends under load, and the bending amplitude is the amplitude required for the knee joint to bend during normal sitting of the human body. Standing-up movement in the sitting-down mode: The wearer reduces the pressure on the ground of both the toe and the heel of the prosthetic foot sole at the same time, then shifts the center of gravity of the body forward and increases the pressure on the ground at the same time. Then the control module 4 collects that the toe pressure signal and the heel pressure signal gradually increase from close to zero to close to the maximum preset force value, executes the standing-up movement in the sitting-down mode, starts the motor 22 to drive the lead screw 23 to rotate in the reverse direction so that the slider 13 moves away from the motor 22, and the knee joint of the prosthetic leg extends to the upright state under load. Squatting movement in the squatting mode: The wearer briefly presses the heel of the prosthetic foot sole against the ground, then quickly lifts it off the ground, and then quickly presses the toe against the ground and keeps the toe pressing against the ground. Then the control module 4 collects a brief heel pressure signal and a subsequent continuous toe pressure signal, executes the squatting movement in the squatting mode, starts the motor 22 to drive the lead screw 23 to rotate so that the slider 13 approaches the motor 22, and the knee joint of the prosthetic leg bends under load, and the bending amplitude is the amplitude required for the knee joint to bend during normal squatting of the human body. Stand-up motion in the squatting mode: The wearer gradually shifts the center of gravity of the body to the healthy limb. At the same time, the wearer reduces and then increases the pressure of the toe of the prosthetic footplate on the ground, and increases and then reduces the pressure of the heel on the ground. At the same time, the wearer increases the pressure of the toe and the heel of the prosthetic footplate on the ground. Then, the control module 4 collects that the toe pressure signal gradually increases from near zero to near the maximum preset force value, and at the same time, the heel pressure signal gradually decreases from near the maximum preset force value to near zero, and executes the stand-up motion in the sitting mode, starting the motor 22 to drive the lead screw 23 to rotate in the reverse direction to move the slider 13 away from the motor 22. Under load, the knee joint of the prosthesis extends to the upright state.

[0032] In this embodiment, the control module 4 collects the signals of the toe pressure sensor 26, the heel pressure sensor 29 and the angle sensor 6, and real-time detects the force condition of the prosthetic footplate and the flexion and extension angle of the knee joint, so as to realize intelligent control under different walking modes. This design can effectively improve the adaptability of the prosthesis and make the wearer's actions more natural and smooth in different scenarios.

[0033] Knee joint angle change parameters in each mode: Flat ground mode: Flexion angle range: When a person walks normally, the knee joint flexion angle is generally between 0° and 65° (when taking a step); Extension angle range: When a person stands, the knee joint is close to 0°, that is, in a fully extended state; The flat ground mode is a control mode for various actions in a gait cycle.

[0034] Up-step mode: Flexion angle range: When a person steps up a step, the knee joint flexion angle is generally between 70° and 90°, and the specific angle depends on the step height; Extension angle range: Extend the knee to 0°, that is, in a fully extended state, to support the body weight.

[0035] Down-step mode: Flexion angle range: When a person steps down a step, the knee joint flexion angle is generally between 15° and 40°, depending on the step length and the descending speed; Extension angle range: Usually between 0° and 10°, depending on the walking manner; When stepping down a step, the knee joint bends slowly in the supporting state.

[0036] Sitting mode: Flexion angle range: When a person sits down normally, the knee joint flexion angle is usually between 90° and 120°, and different seat heights may cause angle changes; Extension angle range: There is no extension involved when sitting down, and the knee joint remains in the flexed state.

[0037] Stand-up mode: Flexion angle range: Before standing up, the knee joint is generally between 90° and 120°, depending on the sitting posture before standing up; Extension angle range: After standing up, the knee joint extends to 0° to complete standing.

[0038] 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° during deep squats; Knee extension angle range: When standing up, the knee joint gradually returns from 90° - 150° to the 0° upright state.

[0039] Response mechanism of the intelligent prosthetic limb: 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; Precise control: The motor 22 drives the lead screw 23 to move the slider 13 along the lead screw, precisely controlling the flexion and extension of the knee joint; Dynamic adaptation: In different modes, the flexion and extension angles of the knee joint conform to the natural movement requirements of the human body, making the movement of the wearer more stable and closer to the normal walking posture; The transfer of the center of gravity is from the heel to the sole of the foot, and knee flexion starts according to the actual situation; This design can effectively improve the comfort and adaptability of prosthetic limb wearers in different terrains and different movements, and enhance the safety and naturalness of walking.

[0040] In this embodiment, 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 as follows: 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 it with the preset flexion and extension angle to determine whether the corresponding action has been executed, or whether the actual flexion and extension angle is consistent with the preset flexion and extension angle. If not, the corresponding action is restarted. This effectively improves the precise control and response ability of the prosthetic knee joint. The confirmation mechanism monitors the flexion and extension angle of the prosthetic knee joint in real time through the feedback of the angle sensor 6 and compares it with the preset angle, enabling it to determine whether a predetermined action has been executed, avoiding problems such as inaccurate movement or inability to execute normally of the prosthetic limb, and ensuring the stability and naturalness of the wearer's gait.

[0041] In this embodiment, the control module 4 is provided with a speed mechanism. The speed mechanism is as follows: In one of the walking modes, the control module 4 analyzes the current walking speed of the wearer according to the change rate of the toe pressure signal and the continuous heel pressure signal, and then adjusts the rotation speed of the motor 22 according to the walking speed to make the speed of the flexion and extension movement of the prosthetic knee joint match the walking speed. This makes the flexion and extension movement of the prosthetic knee joint highly match the walking speed, thereby providing a more comfortable and efficient walking experience, effectively solving the problem of poor adaptability of traditional prosthetic knee joints in different gaits, and avoiding problems such as sudden movements or overly slow movements of the prosthetic limb when touching the ground. If the movement is too fast when touching the ground, the system will automatically adjust to avoid unnatural violent reactions of the prosthetic limb; if the movement is too slow when touching the ground, the system will increase the motor rotation speed to ensure the smoothness and timely response of the prosthetic limb movement. In this way, the control module 4 can ensure that the movement of the prosthetic limb is more stable and natural, enhancing the comfort and safety of the wearer.

Claims

1. An AI knee joint, comprising a joint head (1), a calf support (2) and a connecting member (3), wherein the top of the joint head (1) is hinged to the thigh member, and the bottom of the joint head (1) is hinged to the calf support (2) via a first axis (11), the top of the connecting member (3) is connected to the calf support (2), and the bottom of the connecting member (3) is connected to the foot member, characterized in that: A second shaft (12) is provided at the rear of the joint head (1), a slider (13) is hingedly connected to the second shaft (12), a threaded hole is provided on the slider (13), a third shaft (21) is provided at the middle of the calf support (2), the first shaft (11), the second shaft (12) and the third shaft (21) are coaxially arranged, a motor (22) is hingedly connected to the third shaft (21), an output shaft of the motor (22) is connected to a screw rod (23), and the screw rod (23) is threadedly connected to the slider (13); The front side of the calf support (2) is provided with a first pressing portion (24) and a second pressing portion (25) spaced apart from each other, the first pressing portion (24) and the second pressing portion (25) are capable of deformation, and a toe pressure sensor (26) is connected therebetween; when the front portion of the calf support (2) is subjected to load, the first pressing portion (24) and the second pressing portion (25) can be brought closer together to press the toe pressure sensor (26); The rear side of the calf support (2) is provided with a third pressing portion (27) and a fourth pressing portion (28) spaced apart from each other, the third pressing portion (27) and the fourth pressing portion (28) are capable of deformation, and a heel pressure sensor (29) is connected therebetween; when the rear portion of the calf support (2) is subjected to load, the third pressing portion (27) and the fourth pressing portion (28) can be brought closer together to press the heel pressure sensor (29); A control module (4) and a battery (5) are also provided in the calf support (2); 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.

2. The AI ​​knee joint according to claim 1, characterized in that: The calf support (2) is provided with an angle sensor (6), the detection axis of the angle sensor (6) is connected to the first axis (11), and the information output end of the angle sensor (6) is connected to the control module (4).

3. The AI ​​knee joint according to claim 1, characterized in that: The bottom of the joint head (1) is provided with an avoidance groove, and the sliding block (13) and the screw rod (23) extending out of the threaded hole can rotate in the avoidance groove.

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

5. The control method of the AI ​​knee joint according to any one of claims 2 to 4, characterized in that: The control module (4) collects a toe pressure signal from a toe pressure sensor (26) for detecting the force value when the toe of the foot presses the ground; the control module (4) collects a heel pressure signal from a heel pressure sensor (29) for detecting the force value when the heel of the foot presses the ground; the control module (4) collects a flexion and extension angle signal from an angle sensor (6) for detecting the flexion and extension angle of the knee joint; The control module (4) is preset with a plurality of walking modes, the plurality of walking modes comprising a flat ground mode, a stair climbing mode, a stair descending mode, a sitting mode, a squatting mode and a standing up mode; The leg-lifting action in the flat-ground mode: the wearer moves the body's center of gravity forward with the healthy limb, and then only presses the toe of the prosthetic foot plate against the ground and maintains the state of pressing the ground, then the control module (4) collects a continuous toe pressure signal, executes the leg-lifting action in the flat-ground mode, starts the motor (22) to drive the screw rod (23) to rotate so that the slider (13) approaches the motor (22), and the knee joint of the prosthetic limb is bent without supporting the load, and the range of knee flexion is the range of knee joint bending required for normal walking of the human body; The stepping action in the flat ground mode: when the heel of the foot plate presses the ground and keeps pressing the ground, the control module (4) collects a continuous heel pressure signal, executes the stepping action in the flat ground mode, starts the motor (22) to drive the screw rod (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 is extended to an upright state under load; Continuous action in the flat ground mode: after the stepping action in the flat ground mode, the wearer moves the center of gravity forward and performs the leg lifting action in the flat ground mode again, repeating the steps one after another to complete normal walking on the flat ground; The leg-lifting action in the stair-climbing mode is as follows: the wearer moves the body's center of gravity forward through the healthy limb, then only briefly presses the ground with the toe of the prosthetic foot, then quickly leaves the ground, then quickly presses the ground again, and keeps pressing the ground. The control module (4) collects intermittent toe pressure signals, executes the leg-lifting action in the stair-climbing mode, starts the motor (22) to drive the screw rod (23) to rotate so that the slider (13) approaches the motor (22), and the knee joint of the prosthetic limb is bent without supporting the load, and the range of knee flexion is the range of knee joint bending required when the human body normally climbs stairs; The stepping action in the stair-climbing mode: when the heel and toe of the prosthesis press the ground in turn and keep pressing the ground, the control module (4) collects continuous heel pressure signals and toe pressure signals, executes the stepping action in the stair-climbing mode, starts the motor (22) to drive the screw rod (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 is extended to an upright state under load; The continuous action of the stair climbing mode: after the stepping action in the stair climbing mode, the wearer moves the center of gravity forward and performs the leg lifting action in the stair climbing mode again, repeating the steps in sequence until the normal walking on the stairs is completed; The leg extension action in the step-down mode: the wearer bends the healthy limb to move the body's center of gravity forward, extends the prosthesis to the next step, and then only briefly presses the ground with the heel of the prosthesis foot, then quickly leaves the ground, and then quickly presses the ground again, and keeps pressing the ground. The control module (4) collects intermittent heel pressure signals, executes the leg extension action in the step-down mode, starts the motor (22) to drive the screw rod (23) to rotate so that the slider (13) approaches the motor (22), and the knee joint of the prosthesis flexes under load, and the range of flexion is the range of knee joint flexion required when the human body normally steps down the stairs; at the same time, the body's center of gravity is moved forward, and the healthy limb steps onto the next step; The support action of the step-down mode is as follows: the wearer moves the body's center of gravity forward and gradually straightens the healthy limb until it reaches a fully load-bearing support state. At the same time, the heel of the prosthetic foot gradually leaves the ground, and the control module (4) detects that the heel pressure signal gradually weakens, and executes the support action of the step-down mode, starting the motor (22) to drive the screw rod (23) to rotate in the opposite direction so that the slider (13) moves away from the motor (22). The prosthetic knee joint supports the knee extension under the condition that the load is gradually reduced, and the range of knee extension is the range of knee joint extension required when the human body normally steps down; Continuous action of the step-down mode: After the supporting action of the step-down mode, the wearer moves the center of gravity forward and performs the leg extension action of the step-down mode again, and repeats the process until the normal walking of the step-down mode is completed; The sitting down action in the sitting down mode is as follows: the wearer briefly presses the toe of the prosthetic foot plate against the ground, then quickly leaves the ground, and then quickly presses the heel against the ground, so that the heel remains in the state of pressing the ground. The control module (4) collects a brief toe pressure signal and a subsequent continuous heel pressure signal, executes the sitting down action in the sitting down mode, starts the motor (22) to drive the screw rod (23) to rotate so that the slider (13) approaches the motor (22), and the knee joint of the prosthesis flexes under the load, and the flexion range is the range of knee joint flexion required when the human body sits down normally; The standing up action in the sitting down mode: the wearer reduces the pressure of the toe and heel of the prosthetic foot on the ground at the same time, and then moves the body's center of gravity forward while increasing the pressure on the ground. The control module (4) collects the toe pressure signal and the heel pressure signal and gradually increases them from close to zero to close to the maximum preset force value, and performs the standing up action in the sitting down mode. The motor (22) is started to drive the screw rod (23) to rotate in the opposite direction so that the slider (13) is away from the motor (22), and the knee joint of the prosthetic limb is extended to an upright state under the load. The squatting action in the squatting mode is as follows: the wearer briefly presses the heel of the prosthetic foot plate against the ground, then quickly leaves the ground, and then quickly presses the toes against the ground, so that the toes remain in the state of pressing the ground. The control module (4) collects a brief heel pressure signal and a subsequent continuous toe pressure signal, executes the squatting action in the squatting mode, starts the motor (22) to drive the screw rod (23) to rotate so that the slider (13) approaches the motor (22), and the knee joint of the prosthetic limb flexes under load, and the flexion range is the range of knee joint flexion required for a normal squat by a human body; The standing up action in the squatting mode is as follows: the wearer gradually moves the body's center of gravity to the healthy limb, and at the same time, the pressure of the toe of the prosthetic foot on the ground is reduced and then increased, and the pressure of the heel on the ground is increased and then reduced, and at the same time, the pressure of the toe and heel of the prosthetic foot on the ground is increased, then the control module (4) collects the toe pressure signal which gradually increases from close to zero to close to the maximum preset force value, and at the same time, the heel pressure signal gradually decreases from close to the maximum preset force value to close to zero, and performs the standing up action in the sitting mode, starts the motor (22) to drive the screw rod (23) to rotate in the opposite direction so that the slider (13) is away from the motor (22), and the knee joint of the prosthetic limb is extended to an upright state under the load.

6. The AI ​​knee joint control method 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 under multiple walking modes. The mode confirmation mechanism is as follows: in one of the walking modes, the control module (4) 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 (6), 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.

7. The AI ​​knee joint control method according to claim 6, characterized in that: The control module (4) is provided with a speed mechanism, wherein in one of the walking modes, the control module (4) analyzes the current walking speed of the wearer according to the rate of change of the toe pressure signal and the continuous heel pressure signal, and then adjusts the rotation speed of the motor (22) according to the walking speed, so that the speed of the flexion and extension movement of the prosthetic knee joint matches the walking speed.

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