A cushioning stiffness self-adapting ankle prosthesis

Abstract

The present application belongs to the technical field of human body artificial limb, and particularly relates to a foot-ankle artificial limb with adaptive adjustment of buffer stiffness, which comprises a foot plate, an ankle joint connecting seat is fixedly arranged on the foot plate, a rotating shaft is fixedly arranged on the ankle joint connecting seat, a supporting seat is rotatably connected to the rotating shaft, a supporting cylinder is fixedly arranged on the supporting seat, and an ankle joint elastic reset unit and an ankle joint damping adjustment unit are arranged on the two sides of the supporting seat respectively. The gait sensing unit is used to detect the gait in real time, and the buffer stiffness adjustment, the ankle joint damping adjustment and the electromagnetic damping energy return unit are cooperatively controlled by the electric control unit, so that the synchronous adaptive adjustment of the equivalent buffer support stiffness and the ankle joint rotating damping of the foot-ankle artificial limb is realized. The foot-ankle artificial limb can not only ensure the soft foot feeling during walking and the stable support during running, but also can inhibit the rebound impact of the buffer spring and convert the rebound kinetic energy into electric energy for recovery, so that the walking comfort, the running support and the rebound damping performance are effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of human prosthetics technology, and in particular relates to a foot and ankle prosthesis with adaptive adjustment of buffer stiffness. Background Technology

[0002] In modern foot and ankle prostheses, to cushion axial vibrations and ground impacts during walking and improve wearing comfort, elastic elements, such as cushioning springs, are usually incorporated into the prosthesis. These springs absorb and release energy through axial expansion and contraction. When the user's foot lands, their weight is transferred to the cushioning spring through the prosthesis's socket, compressing the spring to absorb impact energy. After the foot leaves the ground, the spring releases its stored energy, assisting in the axial return of the foot to its original position.

[0003] However, the human body has significantly different requirements for the tension of the cushioning springs under different continuous exercise states: when walking, the stride frequency is low and the impact force is small, so the preload of the cushioning spring needs to be small to obtain a smooth foot feel. When entering a continuous running state, the stride frequency is significantly higher than walking and is maintained at a high level, and the impact force is also increased accordingly, so the preload of the cushioning spring needs to be larger to provide sufficient support at the moment of ground contact. At present, the tension of the cushioning springs in most foot and ankle prostheses is either fixed at the factory and cannot be switched with the changes in continuous exercise state, causing users to compromise with the same foot feel in different exercise modes, or although there is an adjustment mechanism, the spring preload needs to be changed manually, which is cumbersome and cannot be automatically adjusted in real time according to gait changes during exercise.

[0004] To address the aforementioned technical problems, this invention proposes a foot and ankle prosthesis with adaptively adjustable buffer stiffness. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a foot and ankle prosthesis with adaptive adjustment of buffer stiffness, which solves the problem that the preload of the buffer elastic element of the foot and ankle prosthesis is difficult to automatically adjust with the movement state, resulting in a difficulty in achieving both walking flexibility and running support; at the same time, the ankle joint rotation damping and axial buffer support state cannot be matched in coordination, resulting in large rebound impact of the buffer spring and difficulty in recovering and utilizing the rebound kinetic energy.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a foot and ankle prosthesis with adaptive adjustment of buffer stiffness, comprising a foot plate, an ankle joint connecting seat fixedly disposed on the foot plate, and a rotating shaft fixedly disposed on the ankle joint connecting seat, a support seat rotatably connected to the rotating shaft, and a support cylinder fixedly disposed on the support seat, and an ankle joint elastic reset unit and an ankle joint damping adjustment unit respectively disposed on both sides of the support seat;

[0007] A slide block is slidably disposed inside the support cylinder. Multiple buffer springs are fixedly disposed between the slide block and the inner bottom surface of the support cylinder. A support column is fixedly disposed on the slide block, and the upper end of the support column extends to the outside of the support cylinder and is fixedly connected to a small leg connecting seat.

[0008] A buffer stiffness adjustment unit is provided between the support cylinder and the support base, an electromagnetic damping energy recovery unit is provided between the buffer stiffness adjustment unit and the slide, and a gait sensing unit is provided inside the support cylinder.

[0009] An electronic control unit is provided on the support base. The electronic control unit is electrically connected to the gait sensing unit, and the electronic control unit can adjust the working status of the buffer stiffness adjustment unit, the electromagnetic damping energy recovery unit and the ankle joint damping adjustment unit according to the feedback of the gait sensing unit.

[0010] In the above-mentioned foot and ankle prosthesis with adaptive adjustment of buffer stiffness, the ankle joint elastic reset unit includes a first protective shell, a slider, and a reset spring. The first protective shell is fixedly disposed on one side of the support base, and one end of the rotating shaft extends into the first protective shell and is fixedly connected to the slider. An arc-shaped groove is provided in the first protective shell, and the slider is slidably connected to the arc-shaped groove. The slider and the end of the arc-shaped groove are fixedly connected by the reset spring.

[0011] In the above-mentioned foot and ankle prosthesis with adaptive adjustment of buffer stiffness, the ankle joint damping adjustment unit includes a second protective shell, a damping disc, two micro electric actuators and two damping blocks. The second protective shell is fixedly disposed on the side of the support base away from the first protective shell. The other end of the rotating shaft extends into the second protective shell and is fixedly connected to the damping disc. Both micro electric actuators are fixedly disposed on the second protective shell, and the output end of the micro electric actuator extends into the second protective shell and is fixedly connected to the corresponding damping block.

[0012] In the aforementioned adaptively adjustable cushioning stiffness foot and ankle prosthesis, the cushioning stiffness adjustment unit includes a servo motor, a worm gear, two worm wheels, and two lead screws. Both lead screws are rotatably mounted within the support cylinder. The slide has a clearance opening that mates with the lead screws. A drive cavity is located on the upper side of the support. The servo motor is fixedly mounted within the drive cavity. The worm gear is rotatably mounted within the drive cavity, with one end of the worm gear being drive-connected to the servo motor. The lower ends of both lead screws extend into the drive cavity and are fixedly sleeved with corresponding worm wheels. Both worm wheels mesh with the worm gear. Threaded blocks are threadedly connected to the upper parts of both lead screws, and a limit link is fixedly mounted between the two threaded blocks. A stop sleeve is fixedly mounted on the lower side of each threaded block. The stop sleeve is used to press against the slide to adjust the preload of the cushioning spring.

[0013] In the above-mentioned foot and ankle prosthesis with adaptive adjustment of buffer stiffness, the electromagnetic damping energy recovery unit includes two coils and two magnetic blocks. The two coils are respectively fixedly sleeved in the corresponding abutment, and the two magnetic blocks are fixedly set on the slide and are respectively located directly below the corresponding coils.

[0014] In the above-mentioned foot and ankle prosthesis with adaptive adjustment of buffer stiffness, the gait sensing unit includes a photoelectric displacement sensor and a sensing plate. The photoelectric displacement sensor is fixedly disposed on the inner bottom surface of the support cylinder, and the sensing plate is fixedly disposed on the lower side of the slide, with the sensing plate located directly above the photoelectric displacement sensor to provide a stable reflective surface to the photoelectric displacement sensor.

[0015] In the above-mentioned foot and ankle prosthesis with adaptive adjustment of buffer stiffness, the electronic control unit includes an electronic control box, and a battery, a PLC controller, a rectifier, a supercapacitor and an electromagnetic relay installed in the electronic control box. The electronic control box is fixedly installed on the support base. The battery is electrically connected to the PLC controller, a photoelectric displacement sensor, a servo motor and a miniature electric actuator to provide working power.

[0016] The signal input terminal of the PLC controller is electrically connected to the photoelectric displacement sensor, and the signal output terminal of the PLC controller is electrically connected to the control terminals of the servo motor, the miniature electric actuator, and the electromagnetic relay, respectively.

[0017] The coil is electrically connected to the charging terminal of the battery via an electromagnetic relay, a rectifier, and a supercapacitor.

[0018] In the above-mentioned foot and ankle prosthesis with adaptive adjustment of buffer stiffness, a limiting slide rod is fixedly provided on the slide block, and the upper end of the limiting slide rod passes through the top of the support cylinder and is fixedly connected to one side extension end of the support column.

[0019] Compared with existing technologies, the advantages of a foot and ankle prosthesis with adaptively adjustable cushioning stiffness are:

[0020] 1. By setting up a gait sensing unit to detect the vertical displacement of the slide in real time and feed it back to the electronic control unit, the electronic control unit determines whether the user is walking or running based on the movement frequency of the slide, and automatically adjusts the preload of the buffer spring accordingly. This achieves adaptive adjustment of the buffer spring stiffness with gait changes. When walking, the buffer spring preload is smaller to provide a smooth foot feel, while when running, the buffer spring preload is larger to provide higher support.

[0021] 2. By setting up a dual-screw synchronous drive mechanism consisting of a servo motor, worm gear, two worm wheels, and two lead screws, and an electromagnetic damping energy recovery unit consisting of coils and magnetic blocks, the coordinated operation of buffer stiffness adjustment and rebound suppression is realized. The buffer stiffness adjustment unit adjusts the preload of the buffer spring precisely by smoothly raising and lowering the sleeve, so that the force on both sides of the slide is uniform. When the slide rebounds, the electromagnetic damping energy recovery unit generates an electromagnetic damping force that naturally increases with the decrease of the distance, which absorbs the rebound energy in stages, effectively reduces the rebound vibration, and at the same time converts the rebound kinetic energy into electrical energy for recovery.

[0022] 3. By setting up a damping adjustment system that combines an ankle joint damping adjustment unit with an electronic control unit, the electronic control unit synchronously controls the micro electric actuator to adjust the pressure of the damping block on the damping disc based on the gait judgment result, so as to realize the synchronous adjustment of the ankle joint rotation damping and the tension of the buffer spring. When running, the rotation damping increases to provide stable support for pushing off the ground, and when walking, the rotation damping decreases, making the foot rotation more flexible, so that the prosthesis has coordinated mechanical characteristics in different movement states. Attached Figure Description

[0023] Figure 1 This is a side view structural diagram of a foot and ankle prosthesis with adaptive adjustment of buffer stiffness provided by the present invention;

[0024] Figure 2 This is a front view schematic diagram of a foot and ankle prosthesis with adaptive adjustment of buffer stiffness provided by the present invention;

[0025] Figure 3 This is a frontal sectional view of the support cylinder and support seat of a foot and ankle prosthesis with adaptive adjustment of buffer stiffness provided by the present invention.

[0026] Figure 4 This is a side sectional view of the screw and slide of a foot and ankle prosthesis with adaptive adjustment of buffer stiffness provided by the present invention.

[0027] Figure 5 This is a side sectional view of the ankle joint elastic reset unit and the rotating shaft of a foot and ankle prosthesis with adaptive adjustment of buffer stiffness provided by the present invention.

[0028] Figure 6 This is a top sectional view of the ankle joint damping adjustment unit and the rotating shaft of a foot and ankle prosthesis with adaptive adjustment of buffer stiffness provided by the present invention.

[0029] Figure 7 This is a schematic diagram of the internal structure of the electrical control box of a foot and ankle prosthesis with adaptive buffer stiffness adjustment provided by the present invention.

[0030] In the diagram: 1 Footplate, 2 Ankle joint connector, 3 Rotating shaft, 4 Support base, 5 Support cylinder, 6 Ankle joint elastic reset unit, 61 First protective shell, 62 Slider, 63 Reset spring, 7 Ankle joint damping adjustment unit, 71 Second protective shell, 72 Damping disc, 73 Miniature electric actuator, 74 Damping block, 8 Slide seat, 9 Buffer spring, 10 Support column, 11 Lower leg connector, 12 Buffer stiffness adjustment unit, 121 Servo motor, 122 Worm gear, 123 Worm wheel, 124 Lead screw, 13 Electromagnetic damping energy return unit, 131 Coil, 132 Magnetic block, 14 Gait sensing unit, 141 Photoelectric displacement sensor, 142 Sensing plate, 15 Electronic control unit, 151 Electronic control box, 152 Battery, 153 PLC controller, 154 rectifier, 155 supercapacitor, 156 electromagnetic relay, 16 arc-shaped slide, 17 clearance port, 18 threaded block, 19 limit link, 20 abutment sleeve, 21 limit slide bar, 22 drive cavity. Detailed Implementation

[0031] Specific embodiments of the present invention will now be described in detail. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other instances, well-known circuits, software, or methods have not been specifically described to avoid obscuring the invention.

[0032] like Figures 1-7 As shown, a foot and ankle prosthesis with adaptive buffer stiffness adjustment includes a foot plate 1, an ankle joint connecting seat 2 fixedly mounted on the foot plate 1, a rotating shaft 3 fixedly mounted on the ankle joint connecting seat 2, a support seat 4 rotatably connected to the rotating shaft 3, a support cylinder 5 fixedly mounted on the support seat 4, and an ankle joint elastic reset unit 6 and an ankle joint damping adjustment unit 7 respectively mounted on both sides of the support seat 4.

[0033] The ankle joint elastic reduction unit 6 includes a first protective shell 61, a slider 62, and a reduction spring 63. The first protective shell 61 is fixedly disposed on one side of the support base 4, and one end of the rotating shaft 3 extends into the first protective shell 61 and is fixedly connected to the slider 62. An arc-shaped groove 16 is provided in the first protective shell 61. The slider 62 is slidably connected to the arc-shaped groove 16, and the ends of the slider 62 and the arc-shaped groove 16 are fixedly connected by the reduction spring 63. By setting the reduction spring 63 to cooperate with the arc-shaped groove 16, the reduction spring 63 provides elastic reduction force for the plantar flexion and dorsiflexion rotation of the foot plate 1, so that the foot plate 1 can automatically return to the center after leaving the ground. The arc-shaped groove 16 limits the rotation angle of the rotating shaft 3 to prevent the foot plate 1 from over-rotating and ensure the safety and stability of the ankle joint rotation.

[0034] The ankle joint damping adjustment unit 7 includes a second protective shell 71, a damping disc 72, two micro electric actuators 73, and two damping blocks 74. The second protective shell 71 is fixedly installed on the side of the support base 4 away from the first protective shell 61. The other end of the rotating shaft 3 extends into the second protective shell 71 and is fixedly connected to the damping disc 72. The two micro electric actuators 73 are fixedly installed on the second protective shell 71. The two micro electric actuators 73 are symmetrically arranged, and the output end of the micro electric actuators 73 extends into the second protective shell 71 and is fixedly connected to the corresponding damping blocks 74. By setting two symmetrically arranged micro electric actuators 73 to drive the corresponding damping blocks 74 to press the damping disc 72 from both sides, symmetrical adjustment of ankle joint rotation damping is achieved, so that the damping disc 72 is evenly stressed. The damping force can be flexibly adjusted according to gait requirements, improving the support stability and rotation flexibility of the ankle joint under different movement states.

[0035] A slide block 8 is slidably installed inside the support cylinder 5. Multiple buffer springs 9 are fixedly installed between the slide block 8 and the inner bottom surface of the support cylinder 5. A support column 10 is fixedly installed on the slide block 8, and the upper end of the support column 10 extends to the outside of the support cylinder 5 and is fixedly connected to a small leg connecting seat 11. Multiple heat dissipation holes are also provided on the support cylinder 5, and dustproof nets are covered on the heat dissipation holes. The heat dissipation holes facilitate heat dissipation of the support cylinder 5, and the dustproof nets can prevent dust. A limiting slide rod 21 is fixedly installed on the slide block 8, and the upper end of the limiting slide rod 21 passes through the top of the support cylinder 5 and is fixedly connected to one side extension end of the support column 10. The limiting slide rod 21 can constrain the slide block 8 and prevent the slide block 8 from rotating circumferentially during axial movement.

[0036] A buffer stiffness adjustment unit 12 is provided between the support cylinder 5 and the support base 4. The buffer stiffness adjustment unit 12 is used to adjust the preload of the buffer spring 9. The buffer stiffness adjustment of the present invention refers to changing the equivalent buffer support stiffness of the ankle prosthesis at the initial ground contact by changing the preload and initial compression of the buffer spring 9. The buffer stiffness adjustment unit 12 includes a servo motor 121, a worm gear 122, two worm wheels 123 and two lead screws 124. Both lead screws 124 are rotatably mounted inside the support cylinder 5. The slide 8 has a clearance opening 17 that cooperates with the lead screw 124. The upper side of the support base 4 has a drive cavity 22. The servo motor 121 is fixedly mounted inside the drive cavity 22. The worm gear 122 is rotatably mounted inside the drive cavity 22, and one end of the worm gear 122 is connected to the servo motor 121 for transmission. A safety coupling is also installed between the servo motor 121 and the worm gear 122 to ensure the safety of transmission. The lower ends of the levers 124 extend into the drive cavity 22 and are fixedly sleeved with the corresponding worm gears 123. Both worm gears 123 mesh with the worm 122. The upper parts of the two lead screws 124 are threadedly connected with threaded blocks 18, and a limit link 19 is fixedly provided between the two threaded blocks 18. The limit link 19 can limit the two threaded blocks 18 to each other, preventing the threaded blocks 18 from rotating with the lead screws 124. A stop sleeve 20 is fixedly provided on the lower side of the threaded block 18. The stop sleeve 20 is used to press against the slide 8 to adjust the preload of the buffer spring 9. By setting a synchronous drive mechanism composed of a servo motor 121, a worm 122, two worm gears 123 and two lead screws 124, the stop sleeve 20 can be raised and lowered smoothly, so that the slide 8 is evenly stressed and moves smoothly, thereby stabilizing the adjustment of the preload of the buffer spring 9. The self-locking characteristics of the worm 122 and the worm gears 123 can further lock the position of the threaded blocks 18.

[0037] An electromagnetic damping energy recovery unit 13 is provided between the buffer stiffness adjustment unit 12 and the slide 8. The electromagnetic damping energy recovery unit 13 includes two coils 131 and two magnetic blocks 132. The two coils 131 are respectively fixedly sleeved in the corresponding abutment 20. The two magnetic blocks 132 are fixedly set on the slide 8 and are respectively located directly below the corresponding coils 131. By setting the coils 131 and magnetic blocks 132 to cooperate, when the slide 8 rebounds, the damping force generated by electromagnetic induction naturally increases as the distance decreases. The rebound energy of the buffer spring 9 is absorbed in stages, thereby effectively reducing the rebound vibration and avoiding direct rigid impact between the slide 8 and the abutment 20. At the same time, the rebound kinetic energy is converted into electrical energy for recovery.

[0038] A gait sensing unit 14 is installed inside the support cylinder 5. The gait sensing unit 14 includes a photoelectric displacement sensor 141 and a sensing plate 142. The photoelectric displacement sensor 141 is fixedly installed on the inner bottom surface of the support cylinder 5, and the sensing plate 142 is fixedly installed on the lower side of the slide block 8, with the sensing plate 142 located directly above the photoelectric displacement sensor 141. This provides a stable reflective surface for the photoelectric displacement sensor 141. By setting the photoelectric displacement sensor 141 and the sensing plate 142 on the lower side of the slide block 8 to cooperate, non-contact detection of the vertical displacement of the slide block 8 is achieved. The sensing plate 142 provides a stable reflective surface, ensuring that the displacement signal is accurate and reliable. In practical applications, a telescopic dust cover is also fixedly installed between the slide block 8 and the inner bottom surface of the support cylinder 5. Both the photoelectric displacement sensor 141 and the sensing plate 142 are covered inside the telescopic dust cover to block external dust and stray light, ensuring the stability and reliability of displacement detection.

[0039] An electronic control unit 15 is installed on the support base 4. The electronic control unit 15 is electrically connected to the gait sensing unit 14. The electronic control unit 15 can adjust the working status of the buffer stiffness adjustment unit 12, the electromagnetic damping energy return unit 13 and the ankle joint damping adjustment unit 7 according to the feedback of the gait sensing unit 14. The electronic control unit 15 includes an electronic control box 151, and a battery 152, a PLC controller 153, a rectifier 154, a supercapacitor 155 and an electromagnetic relay 156 installed in the electronic control box 151. The electronic control box 151 is fixedly installed on the support base 4. The battery 152 is electrically connected to the PLC controller 153, the photoelectric displacement sensor 141, the servo motor 121 and the miniature electric actuator 73 to provide working power. A charging port and a power display screen are also provided on the outside of the electronic control box 151 to facilitate users to charge and check the remaining power.

[0040] The signal input terminal of the PLC controller 153 is electrically connected to the photoelectric displacement sensor 141, and the signal output terminal of the PLC controller 153 is electrically connected to the control terminals of the servo motor 121, the micro electric actuator 73, and the electromagnetic relay 156, respectively. This allows the PLC controller 153 to control the servo motor 121, the micro electric actuator 73, and the electromagnetic relay 156 based on the feedback from the gait sensing unit 14. In addition, a pressure sensor that works in conjunction with the PLC controller 153 is provided between the output terminal of the micro electric actuator 73 and the damping block 74 to detect the clamping force of the damping block 74 on the damping disk 72 in real time, so as to assist the PLC controller 153 in regulating the thrust of the micro electric actuator 73.

[0041] The coil 131 is electrically connected to the charging terminal of the battery 152 through the electromagnetic relay 156, rectifier 154 and supercapacitor 155. By setting the electromagnetic relay 156, the coil 131 is controlled to connect to the charging circuit only during the rebound stage. The rebound kinetic energy is converted into electrical energy, which is then rectified by the rectifier 154 and then smoothly supplied to the battery 152 through the supercapacitor 155. At the same time, the unidirectional conductivity of the rectifier 154 is used to prevent the current of the battery 152 from flowing back to the coil 131, thus ensuring the safety of energy recovery.

[0042] The operating principle of the present invention is described as follows:

[0043] When the user wears this prosthesis to walk or run, the footplate 1 periodically completes the landing and lifting actions. When the footplate 1 touches the ground, the body weight is transmitted to the slide seat 8 through the lower leg connecting seat 11 and the support column 10. The slide seat 8 compresses the buffer spring 9 to absorb the impact energy of the ground. At the same time, the footplate 1 rotates in plantar flexion or dorsiflexion. The return spring 63 is compressed or stretched to store elastic return force. When the footplate 1 leaves the ground, the buffer spring 9 releases energy, causing the slide seat 8 to rebound upward relative to the support cylinder 5. The return spring 63 releases energy simultaneously to make the footplate 1 automatically return to center.

[0044] The gait sensing unit 14 detects the vertical displacement of the slide 8 in real time and sends the displacement signal to the PLC controller 153. The PLC controller 153 calculates the movement frequency of the slide 8 per unit time. When the movement frequency is lower than the preset threshold, it is determined to be in walking mode. At this time, the buffer spring 9 should be loose to provide a smooth foot feel. When the movement frequency continues to exceed the threshold and is maintained for a preset time, it is determined to be in running mode. At this time, the buffer spring 9 should be tight to provide higher support. For occasional fluctuations in gait, the PLC controller 153 does not trigger adjustment. It only performs switching when the movement frequency continuously reaches the preset threshold to avoid frequent adjustment.

[0045] When the tension of the buffer spring 9 needs to be switched, the PLC controller 153 controls the servo motor 121 to rotate forward or backward based on the gait judgment result. This drives the lead screw 124 to rotate via the worm gear 122 and worm wheel 123, causing the threaded block 18 to move the abutment sleeve 20. The movement distance of the abutment sleeve 20 is determined by the PLC controller 153 through controlling the number of rotations of the servo motor 121. Adjustment stops when the number of rotations reaches a preset value corresponding to the target displacement. When switching to running mode, the abutment sleeve 20 needs to be lowered to increase the preload. The PLC controller 153 then adjusts the tension based on the gait sensing unit 14. The slide block 8 displacement signal is fed back. When the slide block 8 is in the pressing stage, the downward movement is performed. The judgment of the pressing stage is that the slide block 8 continues to move downward from near the upper stop point, indicating that the buffer spring 9 is being compressed. At this time, the downward movement direction of the abutment 20 is consistent with the movement direction of the slide block 8. The servo motor 121 has a small load and smooth adjustment. If the entire downward movement is not completed in a single ground contact stage, the PLC controller 153 continues to execute step by step in the subsequent ground contact stages until the abutment 20 reaches the preset position. When switching to the walking state, the abutment 20 needs to be moved upward to reduce the preload. The upward movement can be performed at any time.

[0046] Synchronously, the PLC controller 153 controls the ankle joint damping adjustment unit 7 according to the gait. When running, the thrust of the micro electric push rod 73 is increased, the clamping force of the damping block 74 on the damping disc 72 is increased, and the rotational damping is increased accordingly, providing stable support for pushing off the ground. When walking, the thrust is reduced, and the clamping force and rotational damping are reduced accordingly, so that the foot plate 1 can rotate more flexibly with the terrain during walking, improving ground contact and comfort.

[0047] During the stage when foot plate 1 touches the ground and slide 8 presses down, PLC controller 153 controls electromagnetic relay 156 to remain open, and coil 131 is not connected to the charging circuit to avoid electromagnetic force interfering with the normal compression of buffer spring 9. When foot plate 1 leaves the ground and enters the rebound stage, PLC controller 153 controls electromagnetic relay 156 to close, connecting coil 131 to the charging circuit composed of rectifier 154 and supercapacitor 155. When slide 8 moves upward, magnetic block 132 will gradually approach coil 131, and the coil 131 will... As the magnetic flux increases, an induced current is generated. After being rectified by the rectifier 154, the current is fed into the supercapacitor 155 and charges the battery 152. According to Lenz's law, the magnetic field generated by the induced current always opposes the magnetic block 132 from approaching, forming an electromagnetic damping force. In the early stage of rebound, the distance between the magnetic block 132 and the coil 131 is relatively large, and the damping force is weak, allowing the spring to release energy smoothly. As the slide 8 approaches the top dead center, the distance decreases sharply, and the damping force is significantly enhanced, converting the kinetic energy at the end of the rebound into electrical energy, thus avoiding rigid impact and recovering energy.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A foot-ankle prosthesis with adaptive adjustment of the cushioning stiffness, comprising a foot plate (1), characterized in that An ankle joint connecting seat (2) is fixedly installed on the foot plate (1), and a rotating shaft (3) is fixedly installed on the ankle joint connecting seat (2). A support seat (4) is rotatably connected to the rotating shaft (3), and a support cylinder (5) is fixedly installed on the support seat (4). An ankle joint elastic reset unit (6) and an ankle joint damping adjustment unit (7) are respectively installed on both sides of the support seat (4). A slide block (8) is slidably arranged inside the support cylinder (5). Multiple buffer springs (9) are fixedly arranged between the slide block (8) and the inner bottom surface of the support cylinder (5). A support column (10) is fixedly arranged on the slide block (8), and the upper end of the support column (10) extends to the outside of the support cylinder (5) and is fixedly connected to a small leg connecting seat (11). A buffer stiffness adjustment unit (12) is provided between the support cylinder (5) and the support base (4), an electromagnetic damping energy recovery unit (13) is provided between the buffer stiffness adjustment unit (12) and the slide (8), and a gait sensing unit (14) is provided inside the support cylinder (5). An electronic control unit (15) is provided on the support base (4). The electronic control unit (15) is electrically connected to the gait sensing unit (14), and the electronic control unit (15) can adjust the working status of the buffer stiffness adjustment unit (12), the electromagnetic damping energy recovery unit (13) and the ankle joint damping adjustment unit (7) according to the feedback of the gait sensing unit (14).

2. The foot and ankle prosthesis with adaptively adjustable buffer stiffness according to claim 1, characterized in that, The ankle joint elastic reset unit (6) includes a first protective shell (61), a slider (62) and a reset spring (63). The first protective shell (61) is fixedly disposed on one side of the support base (4), and one end of the rotating shaft (3) extends into the first protective shell (61) and is fixedly connected to the slider (62). An arc-shaped groove (16) is provided in the first protective shell (61). The slider (62) is slidably connected to the arc-shaped groove (16), and the ends of the slider (62) and the arc-shaped groove (16) are fixedly connected by the reset spring (63).

3. The foot and ankle prosthesis with adaptively adjustable buffer stiffness according to claim 2, characterized in that, The ankle joint damping adjustment unit (7) includes a second protective shell (71), a damping disc (72), two micro electric actuators (73) and two damping blocks (74). The second protective shell (71) is fixedly installed on the side of the support base (4) away from the first protective shell (61). The other end of the rotating shaft (3) extends into the second protective shell (71) and is fixedly connected to the damping disc (72). The two micro electric actuators (73) are fixedly installed on the second protective shell (71), and the output end of the micro electric actuator (73) extends into the second protective shell (71) and is fixedly connected to the corresponding damping block (74).

4. The foot and ankle prosthesis with adaptively adjustable cushioning stiffness according to claim 3, characterized in that, The buffer stiffness adjustment unit (12) includes a servo motor (121), a worm gear (122), two worm wheels (123), and two lead screws (124). Both lead screws (124) are rotatably mounted within the support cylinder (5). The slide block (8) has a clearance opening (17) that cooperates with the lead screws (124). The upper side of the support block (4) has a drive cavity (22). The servo motor (121) is fixedly mounted within the drive cavity (22), and the worm gear (122) is rotatably mounted within the drive cavity (22). One end of the worm gear (122)... The two leadscrews (124) are connected to the servo motor (121) for transmission. The lower ends of the two leadscrews (124) extend into the drive cavity (22) and are fixedly sleeved with the corresponding worm gears (123). The two worm gears (123) mesh with the worm (122). The upper part of the two leadscrews (124) is threaded with threaded blocks (18), and a limit link (19) is fixedly provided between the two threaded blocks (18). A retaining sleeve (20) is fixedly provided on the lower side of the threaded block (18). The retaining sleeve (20) is used to press against the slide (8) to adjust the preload of the buffer spring (9).

5. The foot and ankle prosthesis with adaptively adjustable buffer stiffness according to claim 4, characterized in that, The electromagnetic damping regenerative unit (13) includes two coils (131) and two magnetic blocks (132). The two coils (131) are respectively fixedly sleeved in the corresponding sleeves (20), and the two magnetic blocks (132) are fixedly set on the slide (8) and are respectively located directly below the corresponding coils (131).

6. The foot and ankle prosthesis with adaptively adjustable buffer stiffness according to claim 5, characterized in that, The gait sensing unit (14) includes a photoelectric displacement sensor (141) and a sensing plate (142). The photoelectric displacement sensor (141) is fixedly disposed on the inner bottom surface of the support cylinder (5), and the sensing plate (142) is fixedly disposed on the lower side of the slide (8). The sensing plate (142) is located directly above the photoelectric displacement sensor (141) and is used to provide a stable reflective surface to the photoelectric displacement sensor (141).

7. The foot and ankle prosthesis with adaptively adjustable buffer stiffness according to claim 6, characterized in that, The electrical control unit (15) includes an electrical control box (151), and a battery (152), a PLC controller (153), a rectifier (154), a supercapacitor (155), and an electromagnetic relay (156) installed in the electrical control box (151). The electrical control box (151) is fixedly mounted on the support base (4). The battery (152) is electrically connected to the PLC controller (153), the photoelectric displacement sensor (141), the servo motor (121), and the miniature electric actuator (73) to provide working power. The signal input terminal of the PLC controller (153) is electrically connected to the photoelectric displacement sensor (141), and the signal output terminal of the PLC controller (153) is electrically connected to the control terminals of the servo motor (121), the miniature electric push rod (73), and the electromagnetic relay (156), respectively. The coil (131) is electrically connected to the charging terminal of the battery (152) via an electromagnetic relay (156), a rectifier (154), and a supercapacitor (155).

8. The foot and ankle prosthesis with adaptively adjustable buffer stiffness according to claim 1, characterized in that, A limiting slide rod (21) is fixedly installed on the slide block (8), and the upper end of the limiting slide rod (21) passes through the top of the support cylinder (5) and is fixedly connected to one side extension end of the support column (10).

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