A new intelligent bionic hydraulic carbon fiber artificial foot

Abstract

The application provides a novel intelligent bionic hydraulic carbon fiber artificial foot, and relates to the field of artificial feet, which comprises a foot plate, a connecting seat, an ankle joint shell, a strain gauge and an electro-hydraulic damping cylinder. The electro-hydraulic damping cylinder comprises a cylinder body and a throttle valve assembly, and the throttle valve assembly comprises a telescopic rod, a throttle valve and a support rod which are connected with each other from top to bottom. The throttle valve comprises a valve body, a throttle valve sleeve is fixed to the bottom of the valve body along the axial direction of the cylinder body, a through hole is formed in the throttle valve sleeve along the axial direction of the cylinder body, a throttle valve core which can move up and down is inserted into the through hole, and a throttle port is formed in the side wall of the throttle valve sleeve. The coil magnet drives the throttle valve core to move in the through hole according to the electromagnetic force generated by the coil magnet, so as to change the size of the area of the throttle valve core blocking the throttle port. A displacement sensor is arranged on the valve body and is used for sensing the displacement of the throttle valve core relative to the valve body along the up and down movement of the through hole. A control device is arranged on the outer wall of the cylinder body and comprises an inertia sensor and a microprocessor. According to the artificial foot provided by the application, the structure is simple, and the corresponding optimal damping can be actively adjusted.

Description

Technical Field

[0001] This invention relates to the field of prosthetic feet, and more particularly to a novel intelligent bionic hydraulic carbon fiber prosthetic foot. Background Technology

[0002] People with disabilities account for 6.34% of my country's total population, including more than 1.7 million lower limb amputees. In recent years, due to factors such as disease, traffic accidents, work-related injuries, and natural disasters, the number of thigh amputations has been increasing year by year, causing inconvenience to the lives of amputees and placing a huge burden on society. As people's living standards improve, the performance requirements for prostheses are also getting higher and higher.

[0003] Currently, domestically developed prosthetic foot products mainly include carbon fiber foot plates and carbon fiber foot plates combined with hydraulic ankle joints. However, the ankle joint damping performance needs to be adjusted manually, and it is impossible to automatically adjust the ankle joint damping performance according to changes in road conditions. This is very inconvenient for patients to use and cannot achieve the biomimetic characteristics of the human body's natural gait.

[0004] In addition, the damping cylinder in the existing prosthetic foot generally includes a cylinder body structure with two relatively sealed chambers, as well as a piston rod and piston for squeezing the liquid in the chambers. At the same time, two throttle valves need to be installed in the cylinder body to complete the liquid flow between the two chambers, making the overall structure complex. Furthermore, when the liquid flows, it goes from one chamber through the corresponding throttle valve to the other chamber, resulting in a single flow path. The damping adjustment performance of the damping cylinder still needs to be improved.

[0005] Therefore, a new type of intelligent bionic hydraulic carbon fiber prosthetic foot is needed to at least partially solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a novel intelligent bionic hydraulic carbon fiber prosthetic foot that can actively adjust damping to achieve optimal damping for the corresponding terrain and gait stage. Its electro-hydraulic damping cylinder has a simple structure, small size, better damping adjustment performance, and can achieve precise damping control.

[0007] This invention provides a novel intelligent bionic hydraulic carbon fiber prosthetic foot, the prosthetic foot comprising:

[0008] foot;

[0009] Connector to the footplate;

[0010] An ankle joint housing with a truncated quadrangular shape mounted on top, and the bottom of the ankle joint housing is pivotally connected to the middle of the connecting seat via a sensing shaft for sensing the joint rotation angle.

[0011] Strain gauges are placed between the ankle joint housing and the frustum to sense vertical tensile and compressive forces and plantar dorsiflexion torque;

[0012] An electro-hydraulic damping cylinder, disposed inside the ankle joint housing, includes a sealed cylinder body and a throttle valve assembly extending beyond the cylinder body at both ends. The throttle valve assembly includes a telescopic rod, a throttle valve, and a support rod arranged from top to bottom along the cylinder body axis and interconnected. The top of the cylinder body is rotatably connected to the ankle joint housing via a horizontal pin, and the bottom of the support rod is rotatably connected to the front end of a connecting seat via a horizontal connecting rod.

[0013] The throttle valve located in the inner cavity of the cylinder includes a valve body containing a fourth cavity. The outer wall of the valve body is provided with a first sealing plug extending radially outward. The first sealing plug divides the inner cavity of the cylinder into a first cavity and a second cavity. A throttle valve sleeve is fixed at the bottom of the valve body along the cylinder axial direction. The throttle valve sleeve is provided with a through hole along the cylinder axial direction that connects to the fourth cavity and to the first cavity via a first oil passage. A throttle valve core that can move up and down along the through hole is tightly inserted at the end of the through hole near the fourth cavity. A throttle port that connects the second cavity and the through hole is provided on the side wall of the throttle valve sleeve.

[0014] A coil and a coil magnet are installed on the inner wall of the valve body. The coil magnet is used to drive the throttle valve core to move in the through hole according to the electromagnetic force generated by the coil under the action of the coil, so as to change the area of ​​the throttle valve core blocking the throttle orifice.

[0015] A displacement sensor is installed on the valve body to sense the amount of displacement of the throttle valve core relative to the valve body as it moves up and down along the through-hole; and

[0016] The control device, mounted on the outer wall of the cylinder, includes an inertial sensor for sensing motion acceleration signals and tilt angles, and a microprocessor.

[0017] When the prosthetic foot performs plantar dorsiflexion, the microprocessor is used to: calculate the optimal damping coefficient based on data sensed by the sensing shaft, strain gauge, and inertial sensor respectively; obtain the actual damping coefficient based on the equivalent model of the strain gauge and the instantaneous velocity of the throttle valve core; and adjust the coil current to drive the throttle valve core to move within the through hole based on the PID algorithm (proportional-integral-derivative algorithm) so that the actual damping coefficient is close to the optimal damping coefficient, thereby achieving optimal damping.

[0018] According to the present invention, the prosthetic foot, through a sensing shaft, strain gauge, inertial sensor, displacement sensor, electro-hydraulic damping cylinder and control device, obtains the corresponding optimal damping coefficient based on the identified terrain and gait stage during plantar dorsiflexion. By adjusting the coil current to drive the throttle valve core to move within the through hole, the actual damping coefficient is made close to the optimal damping coefficient, thereby achieving active damping adjustment to reach the optimal damping for the corresponding terrain and gait stage.

[0019] In addition, the electro-hydraulic damping cylinder in the prosthetic foot of the present invention includes a telescopic rod, a throttle valve and a support rod arranged from top to bottom on the cylinder axis, which are connected to each other. The throttle valve is arranged in the inner cavity of the cylinder, which makes the electro-hydraulic damping cylinder simple in structure and small in size. At the same time, by setting a displacement sensor, a coil and a coil magnet, the damping magnitude can be precisely controlled.

[0020] Optionally, the top of the throttle valve core outside the through hole is configured as a positioning protrusion extending radially outward, and the bottom inner wall of the valve body is provided with a stop block sleeved on the throttle valve sleeve. The stop block is provided with a limiting groove to accommodate the positioning protrusion, so that when the positioning protrusion abuts downward to the limiting groove, the throttle port is not completely blocked by the throttle valve core, so as to maintain communication.

[0021] The top of the positioning protrusion is also inserted with a positioning part along the axial direction of the cylinder body, so that when the positioning part abuts against the top inner wall of the valve body, the throttle valve core is still inserted in the through hole.

[0022] The displacement sensor includes a magnetic ring sleeved on the positioning part and a Hall sensor fixed to the valve body.

[0023] According to this solution, the positioning protrusions and stops serve two purposes: firstly, they limit the downward movement of the throttle valve core; secondly, while limiting the throttle valve core, they also ensure that the throttle orifice is not completely blocked by the throttle valve core, thus maintaining connectivity and allowing oil flow. Furthermore, the positioning part limits the upward movement of the throttle valve core; thirdly, while limiting the throttle valve core, it also ensures that the throttle valve core remains inserted in the through hole, guaranteeing normal operation of the throttle valve core. Finally, it also serves as a mounting structure for the magnetic ring.

[0024] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows, and will also become apparent in part to those skilled in the art upon studying the description, or may be learned by practice of the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures specifically pointed out in the description and drawings.

[0025] Those skilled in the art will understand that the objectives and advantages achievable with the present invention are not limited to those specifically described above, and that the above and other objectives achievable with the present invention will become clearer from the following detailed description. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, are not intended to limit the scope of the invention. The components in the drawings are not drawn to scale but are merely illustrative of the principles of the invention. For ease of illustration and description of certain parts of the invention, corresponding portions in the drawings may be enlarged, i.e., may appear larger relative to other components in an exemplary device actually manufactured according to the invention. In the drawings:

[0027] Figure 1 This is a schematic diagram of the structure of a prosthetic foot according to an embodiment of the present invention;

[0028] Figure 2 for Figure 1 Another angle diagram of the prosthetic foot shown;

[0029] Figure 3 This is a schematic diagram of the connecting seat in a prosthetic foot according to an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the internal structure of the electro-hydraulic damping cylinder in a prosthetic foot according to an embodiment of the present invention;

[0031] Figure 5 for Figure 4 An enlarged schematic diagram of part A in the diagram; and

[0032] Figure 6 This is a schematic diagram of the connection frame of a portion of the structure in a prosthetic foot according to an embodiment of the present invention.

[0033] Explanation of reference numerals in the attached figures:

[0034] 100. Prosthetic foot;

[0035] 110. Footboard;

[0036] 120. Connecting base; 121. First mounting hole; 122. Second mounting hole; 123. Third mounting hole;

[0037] 131. Ankle joint shell; 132. Quadrangular frustum; 133. Sensing shaft; 134. Strain gauge;

[0038] 140. Electro-hydraulic damping cylinder;

[0039] 141. Cylinder block; 1412. Cylinder head; 1413. Pin hole; 1414. Lower end cap; 1415. Oil inlet;

[0040] 142. Telescopic pole;

[0041] 143. Throttling valve;

[0042] 1431, Valve body; 14311, Valve cover; 14312, Valve body;

[0043] 1432, Throttling valve sleeve; 14321, Through hole; 14322, Throttling port; 14323, Third valve port;

[0044] 1433, Throttling valve core; 14331, Second oil passage; 14332, First valve port; 14333, Second valve port; 14334, Positioning protrusion; 14335, Positioning part;

[0045] 144. Piston end cap; 1441. First oil passage; 1442. First branch line; 1443. First check valve; 1444. Second branch line; 1445. Second check valve;

[0046] 145. First sealing plug;

[0047] 1461. Coil; 1462. Coil magnet;

[0048] 147. Magnetic ring;

[0049] 148. Stop block; 1481. Limiting groove;

[0050] 149. Support rod; 1491. Center hole; 1492. Second sealing plug; 1493. Spring; 1494. Connecting hole;

[0051] 150. Control device; 151. Inertial sensor;

[0052] Q1, First cavity; Q2, Second cavity; Q3, Third cavity; Q4, Fourth cavity. Detailed Implementation

[0053] The objects and functions of the present invention, as well as the methods for achieving these objects and functions, will be clarified by referring to exemplary embodiments. However, the present invention is not limited to the exemplary embodiments disclosed below; it can be implemented in various forms. The purpose of this specification is merely to help those skilled in the art to comprehensively understand the specific details of the invention.

[0054] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0055] The ordinal numbers such as "first" and "second" used in this invention are merely identifiers and do not have any other meaning, such as a specific order. Moreover, for example, the term "first component" does not imply the existence of "second component," and the term "second component" does not imply the existence of "first component."

[0056] It should be noted that the terms “up,” “down,” “front,” “back,” “left,” “right,” “inner,” “outer,” and similar expressions used in this article are for illustrative purposes only and are not intended to be limiting.

[0057] This invention provides a novel intelligent bionic hydraulic carbon fiber prosthetic foot 100. The prosthetic foot 100 can be applied, for example, in the field of rehabilitation aids, and can solve problems such as complex structure, inaccurate damping control, and insufficient damping adjustment found in existing prosthetic feet.

[0058] To address the above problems, this invention provides a novel intelligent biomimetic hydraulic carbon fiber prosthetic foot 100. In a preferred embodiment, as... Figure 1 , Figure 2 and Figure 4 As shown, where Figure 1 This is a schematic diagram of the structure of a prosthetic foot according to an embodiment of the present invention; Figure 2 for Figure 1 Another angle diagram of the prosthetic foot shown; Figure 4 This is a schematic diagram of the internal structure of an electro-hydraulic damping cylinder in a prosthetic foot according to an embodiment of the present invention. The prosthetic foot 100 may include a foot plate 110, a connecting seat 120, an ankle joint housing 131, a strain gauge 134, an electro-hydraulic damping cylinder 140, and a control device 150.

[0059] The footplate 110 is used for contact with the ground. The connecting seat 120 connects the footplate 110, the ankle joint housing 131, and the electro-hydraulic damping cylinder 140. The ankle joint housing 131 is used for mounting the strain gauge 134 and the electro-hydraulic damping cylinder 140. The strain gauge 134 senses vertical tensile and compressive forces and plantar dorsiflexion torque. The electro-hydraulic damping cylinder 140 is used to adjust damping. The control device 150 is used to control and achieve optimal damping.

[0060] Specifically, the footplate 110 can be a footplate 110 using existing technology. It can be a carbon fiber footplate 110.

[0061] The rear end is connected to the foot plate 110 via a connecting seat 120. For example, the rear end of the connecting seat 120 can be connected to the foot plate 110 via a vertical fixing bolt.

[0062] An ankle joint housing 131 with a frustum 132 mounted on top. The ankle joint housing 131 may be a rearwardly bent U-shaped housing with a closed top and front end. The bottom of the ankle joint housing 131 is rotatably connected to the center of the connector 120 via a sensing shaft 133. The sensing shaft 133 is used to sense the joint rotation angle. Specifically, the sensing shaft 133 may include a rotational shaft for rotatable connection and an angle sensor. (Reference) Figure 6 The angle sensor may include a permanent magnet and a magnetic angle encoder. For example, the radial direction of the rotating shaft can be constrained by a set screw (not shown), and its axial direction can be constrained by two sensing shaft covers on the left and right sides. The set screw can be fixed to the connecting seat 120 by threads. A radial permanent magnet is fixed to one end of the rotating shaft, and a magnetic angle encoder is fixed to the sensing shaft cover. The engagement gap between the permanent magnet and the magnetic angle encoder is 0.5mm-1.5mm. When the sensing shaft 133 rotates, the current absolute angle value can be obtained in real time through the magnetic angle encoder, providing important angle information for the plantar flexion / dorsiflexion movement of the ankle joint.

[0063] Strain gauge 134 is positioned between ankle joint housing 131 and frustum 132 to sense vertical tensile and compressive forces and plantar dorsiflexion torque.

[0064] An electro-hydraulic damping cylinder 140, disposed inside the ankle joint housing 131, includes a sealed cylinder body 141 and throttle valve 143 assemblies extending beyond the cylinder body 141 at both ends. The sealed cylinder body 141 can be integral or separate. To facilitate the assembly and disassembly of the cylinder body 141, the cylinder body 141 may include a U-shaped cylinder body 1411 with an open top, a cylinder cover 1412 detachably fitted to the top opening of the cylinder body 1411, and a lower end cover 1414 detachably fitted to the bottom of the cylinder body 1411. The detachable connection method can be screwed, snap-fit, or fastened, etc.

[0065] The throttle valve 143 assembly includes a telescopic rod 142, a throttle valve 143, and a support rod 149, which are arranged from top to bottom along the axis of the cylinder body 141 and are interconnected. The top of the cylinder body 141 is rotatably connected to the ankle joint housing 131 via a horizontal pin. The bottom of the support rod 149 is rotatably connected to the front end of the connecting seat 120 via a horizontal connecting rod. The cylinder body 141 is axially movable relative to the throttle valve 143 assembly under the action of an external force.

[0066] The throttle valve 143 located in the inner cavity of the cylinder 141 includes a valve body 1431 containing a fourth cavity Q4. A first sealing plug 145 extending radially outward is provided on the outer wall of the valve body 1431. The first sealing plug 145 divides the inner cavity of the cylinder 141 into a first cavity Q1 and a second cavity Q2. A throttle valve core 1432 is fixed axially along the bottom of the valve body 1431. The throttle valve core 1432 is axially provided with a through hole 14321 communicating with the fourth cavity Q4 and communicating with the first cavity Q1 via a first oil passage 1441. The throttle valve core 1433, which can move up and down along the through hole 14321, is tightly inserted into the end of the through hole 14321 near the fourth cavity Q4, i.e., the throttle valve core 1433 seals the end of the through hole 14321 near the fourth cavity Q4. The side wall of the throttle valve core 1432 is provided with a throttle port 14322 that connects the second cavity Q2 and the through hole 14321.

[0067] A coil 1461 and a coil magnet 1462 are disposed on the inner wall of the valve body 1431. The coil magnet 1462, under the action of the coil 1461, drives the throttle valve core 1433 to move within the through-hole 14321 according to the generated electromagnetic force, thereby changing the area of ​​the throttle valve core 1433 blocking the throttle orifice 14322. That is, the excitation current of the coil 1461 can be changed to change the magnitude of the electromagnetic force generated by the coil magnet 1462, thereby changing the moving position of the throttle valve core 1433 within the through-hole 14321, and thus changing the area of ​​the throttle valve core 1433 blocking the throttle orifice 14322. Specifically, during plantar flexion, the throttle valve core 1433 is controlled to block a larger area of ​​the throttle orifice 14322. During dorsiflexion, the throttle valve core 1433 is controlled to block a smaller area of ​​the throttle orifice 14322.

[0068] A displacement sensor is installed on the valve body 1431 to sense the amount of displacement of the throttle valve core 1433 relative to the valve body 1431 as it moves up and down along the through hole 14321.

[0069] The control device 150, mounted on the outer wall of the cylinder block 141, includes an inertial sensor 151 for sensing motion acceleration signals and tilt angles, and a microprocessor. When the prosthetic foot 100 performs plantar dorsiflexion, the microprocessor calculates the optimal damping coefficient based on data sensed by the sensing shaft 133, strain gauge 134, and inertial sensor 151; obtains the actual damping coefficient based on the equivalent model of strain gauge 134 and the instantaneous velocity of the throttle valve core 1433; and adjusts the current of coil 1461 to drive the throttle valve core 1433 to move within the through-hole 14321 using a PID algorithm (proportional-integral-derivative algorithm) to make the actual damping coefficient approach the optimal damping coefficient, thereby achieving optimal damping.

[0070] Specifically, the microprocessor senses the joint rotation angle, vertical tension and compression, plantar dorsiflexion torque, motion acceleration signal, and tilt angle respectively by sensing the joint rotation angle, vertical tension and compression, plantar dorsiflexion torque, motion acceleration signal, and tilt angle by sensing the joint rotation angle, strain gauge, and inertial sensor 151, respectively. After signal processing such as filtering, noise reduction, and feature extraction, these data can be used to identify motion intentions by using pattern recognition or classification algorithms, identify terrain (such as flat ground, uphill and downhill slopes, stairs) and gait stages (such as heel or toe contact with and off the ground). Based on the identified terrain and gait stages, the optimal damping coefficient corresponding to the pre-stored data can be retrieved by using a lookup table method.

[0071] The determination of the optimal damping coefficient can be achieved using existing technologies. For example, the optimal damping coefficient can be pre-established through experiments and training to obtain a mapping table corresponding to the optimal damping coefficient for different working conditions (different terrains and gait stages).

[0072] The method of retrieving the pre-stored one-to-one optimal damping coefficient by looking up a table has the following advantages: 1. The table lookup operation has a small computational load and can be calculated in real time and efficiently; 2. The experimental data implicitly contains the nonlinear characteristics of the system (such as friction and hysteresis), which improves the robustness of the system; 3. The control strategy can be quickly iterated through offline optimization of table parameters, making debugging convenient.

[0073] By employing multimodal ankle joint sensing and electrohydraulic damping adjustment, the ankle joint maintains contact with the ground during changes in angle, resulting in a more symmetrical gait and excellent stability and safety even when walking on slopes and rugged terrain. It can not only recognize road conditions but also automatically adjust the damping cylinder, solving the problem of manual damping in previous models and addressing the inability of passively damped prosthetic feet to provide adjustable damping. This significantly improves the comfort of the patient's residual limb.

[0074] The microprocessor is used to obtain the actual damping coefficient based on the equivalent model of strain gauge 134 and the instantaneous velocity of the throttle valve core 1433, specifically including:

[0075] The damping force F is obtained based on the equivalent model of strain gauge 134. The instantaneous velocity V of the throttle valve core 1433 is calculated using numerical differentiation based on the displacement obtained from the displacement sensor. The actual damping coefficient C is then calculated using the formula C = F / V. Alternatively, the displacement-time curve of the throttle valve core 1433 can be measured through prior dynamic experiments. The instantaneous velocity can be calculated using numerical differentiation, and the nonlinear characteristic curve of the damping coefficient changing with displacement or velocity can be obtained by fitting the force-velocity relationship. During operation, the actual damping coefficient is dynamically calculated based on the real-time displacement and velocity signals of the throttle valve core 1433.

[0076] Furthermore, the control device 150 may also include a communication module for communicating with mobile phones and computers. The control device 150 may also include a power management module for power supply and power management.

[0077] According to the above technical solution, the prosthetic foot 100 of the present invention, through the sensing shaft 133, strain gauge 134, inertial sensor 151, displacement sensor, electro-hydraulic damping cylinder 140 and control device 150, etc., obtains the corresponding optimal damping coefficient according to the identified terrain and gait stage during plantar dorsiflexion. By adjusting the current of the coil 1461 to drive the throttle valve core 1433 to move within the through hole 14321, the actual damping coefficient is made close to the optimal damping coefficient. In this way, the damping is actively adjusted to achieve the best damping for the corresponding terrain and gait stage. Thus, the electro-hydraulic damping cylinder 140 provides the most appropriate damping for the corresponding plantar dorsiflexion or dorsiflexion movement of the ankle joint. Furthermore, the electro-hydraulic damping cylinder 140 includes a telescopic rod 142, a throttle valve 143, and a support rod 149 that are connected to each other from top to bottom on the axis of the cylinder body 141. The throttle valve 143 is arranged in the inner cavity of the cylinder body 141, which makes the electro-hydraulic damping cylinder 140 simple in structure and small in size. At the same time, by setting a displacement sensor, a coil 1461, and a coil magnet 1462, the damping magnitude can be precisely controlled.

[0078] refer to Figure 3 Regarding the connecting seat 120, it may include a seat body extending in the front and rear directions. The seat body may have a first mounting hole 121 for the sensing shaft 133 (rotation shaft) to pass through, a second mounting hole 122 for the connecting rod to pass through, a third mounting hole 123 for the fixing bolt to pass through, and a fourth mounting hole (not shown) communicating with the second mounting hole 122 for mounting a set screw.

[0079] To facilitate the installation of the cylinder block 141, aligned pin holes 1413 for connection can be provided on both sides of the cylinder head 1412. For example, the electro-hydraulic damping cylinder 140 can be rotatably connected to the ankle joint housing 131 via a pin in the pin hole 1413. Of course, an oil inlet 1415 can be provided on the cylinder block 141 near the lower end cover 1414 so that oil can be injected into the cylinder block 141.

[0080] The top of the valve body 1431, containing a fourth cavity Q4, is connected to the telescopic rod 142. The bottom of the valve body 1431 can be connected to the piston end cap 144. A first sealing plug 145 extending radially outward is provided on the outer wall of the valve body 1431. For example, the first sealing plug 145 can be provided at the connection between the outer wall of the valve body 1431 and the piston end cap 144. The other end of the piston end cap 144 can be connected to the support rod 149. The support rod 149 extends axially from the first cavity Q1 downward through the bottom of the cylinder body 141 and outward. The telescopic rod 142 extends axially from the second cavity Q2 upward through the top of the cylinder body 141 and outward.

[0081] It is understood that the bottom and top of the cylinder body 141 are respectively provided with through holes for the support rod 149 and the telescopic rod 142 to pass through, and the corresponding through holes are sealed.

[0082] Furthermore, the valve body 1431 may include a detachably connected gate-type valve cover 14311 and a Y-type valve body 14312 to facilitate the assembly and disassembly of the valve body 1431. The valve cover 14311 and the telescopic rod 142 may be an integral structure.

[0083] The support rod 149 can be screwed onto the protruding part at the bottom of the piston end cap 144. The piston end cap 144 can also be screwed onto the protruding part at the bottom of the valve body 14312. This design allows for detachable connections between the support rod 149 and the piston end cap 144, and between the piston end cap 144 and the valve body 14312, facilitating assembly and disassembly.

[0084] The support rod 149 may have a central hole 1491 with an open top along the axial direction. A spring 1493, with one end connected to the bottom of the support rod 149 and the other end connected to the second sealing plug 1492, is installed in the central hole 1491. The space between the central hole 1491 and the lower end face of the second sealing plug 1492 and the piston end cover 144 forms a third cavity Q3. When the electro-hydraulic damping cylinder 140 is in the zero position, the spring 1493 can have a certain preload, so that the second sealing plug 1492 is almost in contact with the lower end face of the piston end cover 144, and at this time there is almost no oil in the third cavity Q3.

[0085] It is understandable that the center hole 1491 can also be a through hole, and its bottom can be sealed by setting a sealing cap or sealing plug.

[0086] The piston end cap 144 may have a Y-shaped structure. When the piston end cap 144 is connected to the valve body 14312, the recessed portion at the top of the piston end cap 144 may be screwed onto the protruding portion at the bottom of the valve body 14312. A first oil passage 1441 communicating with the first cavity Q1 is provided inside the piston end cap 144. The first oil passage 1441 communicates with the third cavity Q3 via a first branch line 1442 provided with a first one-way valve 1443 and a second branch line 1444 provided with a reverse second one-way valve 1445.

[0087] Regarding the bottom of the valve body 1431 and the throttle valve core 1432, for example, the two can be connected and fixed by screwing.

[0088] refer to Figure 5 The throttle valve core 1433 may also be provided with a second oil passage 14331 along its length, one end of which is connected to the through hole 14321 and the other end of which is connected to the fourth cavity Q4. The side wall of the throttle valve core 1432 is provided with a throttle port 14322 connected to the through hole 14321. The throttle port 14322 can be connected to the second cavity Q2 via a channel opened in the valve body 1431.

[0089] According to the above scheme, the working process of the electro-hydraulic damping cylinder 140 in the prosthetic foot 100 of the present invention is as follows:

[0090] When the electro-hydraulic damping cylinder 140 is in the zero position, there is no oil in the third cavity Q3, and there is oil in the first cavity Q1, the second cavity Q2 and the fourth cavity Q4. The throttle valve core 1433 is in the initial position. At this time, the first valve port 14332 is connected to the fourth cavity Q4, and the second valve port 14333 is not connected to the third valve port 14323.

[0091] Then, when the cylinder 141 moves upward relative to the valve body 1431 under the action of external force (e.g., plantar flexion), the first cavity Q1 is squeezed and begins to discharge oil. After the oil enters the first oil passage 1441, part of it enters the third cavity Q3 through the first branch line 1442 and the first one-way valve 1443, and the third cavity Q3 is filled with oil. The filling of the third cavity Q3 will further compress the spring 1493, which will reset the spring 1493 and prepare for the subsequent filling of the first cavity Q1 with oil. Part of it enters the second cavity Q2 through the through hole 14321 and the throttle port 14322, and the second cavity Q2 is filled with oil. Another part enters the fourth cavity Q4 through the through hole 14321, the second oil passage 14331 and the first valve port 14332 (or through the through hole 14321, the second oil passage 14331, the second valve port 14333 and the third valve port 14323), and the fourth cavity Q4 begins to be filled with oil. Simultaneously, the oil flows through multiple routes in different directions, resulting in better damping adjustment performance. Furthermore, the rate of oil discharge from the first cavity Q1 during this process is controlled by the actual area of ​​the throttle port 14322 that can supply oil flow. This can be achieved by driving the throttle valve core 1433 downwards along the through hole 14321 under the combined electromagnetic force generated by the coil 1461 and the coil magnet 1462. The displacement sensor then controls the distance the throttle valve core 1433 moves downwards along the through hole 14321, thereby controlling the area of ​​the throttle port 14322 blocked by the throttle valve core 1433, and thus precisely controlling the damping magnitude.

[0092] When cylinder block 141 moves downward relative to valve body 1431 under external force (e.g., flexion motion), the area of ​​first cavity Q1 increases, creating negative pressure and initiating oil filling. Simultaneously, second cavity Q2 begins to discharge oil, entering first cavity Q1 through throttle port 14322, through hole 14321, and first oil passage 1441. Fourth cavity Q4 also begins to discharge oil, entering first cavity Q1 through first valve port 14332, second oil passage 14331, through hole 14321, and first oil passage 1441 (or third valve port 14323, second valve port 14333, second oil passage 14331, through hole 14321, and first oil passage 1441). Third cavity Q3 also begins to discharge oil, entering first cavity Q1 through second branch line 1444, second check valve 1445, and first oil passage 1441. At the same time, the oil flows through multiple routes in different directions, resulting in better damping adjustment performance. Furthermore, during this process, the rate at which the first cavity Q1 is filled with oil is controlled by the actual area of ​​the throttle port 14322 that can supply oil flow. This can be achieved by driving the throttle valve core 1433 to move upward along the through hole 14321 under the combined electromagnetic force generated by the coil 1461 and the coil magnet 1462. Similarly, the displacement sensor detects the displacement and controls the distance the throttle valve core 1433 moves upward along the through hole 14321, thereby continuing to control the area of ​​the throttle port 14322 blocked by the throttle valve core 1433, and thus precisely controlling the damping magnitude.

[0093] Therefore, in the electro-hydraulic damping cylinder 140 of the dummy foot 100 according to the present invention, the oil flows through multiple routes in different directions at the same time during damping adjustment, resulting in better damping adjustment performance. Furthermore, the electro-hydraulic damping cylinder 140 of the present invention adopts a closed-loop position control combining electromagnetic force drive and displacement feedback. The excitation current of the regulating coil 1461 dynamically controls the displacement of the throttle valve core 1433, and the displacement sensor synchronously collects the position signal of the throttle valve core 1433, forming a closed-loop adjustment link of "current-electromagnetic force-throttle valve core 1433 displacement". Based on the positive correlation characteristics of electromagnetic force and current and the nonlinear regulation mechanism of the displacement of the throttle valve core 1433 on the hydraulic oil flow, the electro-hydraulic damping cylinder 140 can adjust the displacement of the throttle valve core 1433 according to the required damping force output, thereby realizing the dynamic adjustment of the damping characteristics of the electro-hydraulic damping cylinder 140 and achieving precise damping control. At the same time, it also achieves the purpose of simple structure and small size of the electro-hydraulic damping cylinder 140, thus making the entire dummy foot 100 structurally simple as well.

[0094] In a preferred embodiment, the top of the throttle valve core 1433 outside the through hole 14321 may be a positioning protrusion 14334 extending radially outward. A stop 148 is provided on the bottom inner wall of the valve body 1431, which is fitted onto the throttle valve core 1432. The stop 148 is provided with a limiting groove 1481 to accommodate the positioning protrusion 14334, so that when the positioning protrusion 14334 abuts downward against the limiting groove 1481, the throttle port 14322 may not be completely blocked by the throttle valve core 1433, thus maintaining communication.

[0095] In this way, by setting the positioning protrusion 14334 and the stop 148, on the one hand, the throttle valve core 1433 is limited when it moves downward, and on the other hand, while limiting the throttle valve core 1433, it also ensures that the throttle port 14322 is not completely blocked by the throttle valve core 1433, so as to keep the throttle port 14322 connected and allow the oil to flow.

[0096] refer to Figure 4 A positioning part 14335 can also be inserted into the top of the positioning protrusion 14334 along the axial direction of the cylinder body 141. When the positioning part 14335 abuts against the inner top wall of the valve body 1431, the throttle valve core 1433 is still inserted in the through hole 14321. The specific type of the positioning part 14335 is not strictly limited. For example, it can be a flower-shaped cap bolt, a T-shaped cap bolt, or a round cap bolt, etc., and is inserted into the positioning protrusion 14334 by means of threaded connection.

[0097] The specific type of displacement sensor is not limited. For example, the displacement sensor may include a magnetic ring 147 and a Hall sensor (not shown) fixed to the valve body 1431. The magnetic ring 147 may be sleeved onto the positioning part 14335. The magnetic ring 147 is fixed to the tail end of the throttle valve core 1433. When the magnetic ring 147, which moves with the throttle valve core 1433, moves relative to the linear Hall sensor, the magnetic field strength at the position of the linear Hall sensor changes, thereby allowing the Hall sensor to obtain an accurate displacement value.

[0098] The positioning part 14335 serves three purposes: firstly, it limits the upward movement of the throttle valve core 1433; secondly, it ensures that the throttle valve core 1433 remains inserted in the through hole 14321 while limiting its movement, thus guaranteeing normal operation of the throttle valve core 1433; and thirdly, it can also serve as the mounting structure for the magnetic ring 147.

[0099] Continue to refer to Figure 5To achieve better oil flow between the second oil passage 14331 and the fourth cavity Q4, the sidewall of the throttle valve core 1433 can be provided with a first valve port 14332 and a second valve port 14333 respectively connected to the second oil passage 14331 along its length. The sidewall of the throttle valve core 1432 can also be provided with a third valve port 14323 connected to the fourth cavity Q4. The second valve port 14333 is located between the first valve port 14332 and the third valve port 14323 along the length of the throttle valve core 14333.

[0100] When the throttle valve core 1433 moves up and down in the through hole 14321, at least one of the following remains in a connected state: the first valve port 14332 and the fourth cavity Q4, or the second valve port 14333, the third valve port 14323 and the fourth cavity Q4.

[0101] The first valve port 14332 and the second valve port 14333 can be symmetrically arranged radially to the side wall of the throttle valve core 1433. The third valve port 14323 and the throttle port 14322 can be symmetrically arranged radially to the side wall of the throttle valve core 1432.

[0102] To facilitate the installation of the support rod 149, a horizontal connecting hole 1494 can be provided at the lower part of the support rod 149. For example, the support rod 149 can be connected and fixed to other structures by a connecting rod passing through the connecting hole 1494.

[0103] Other embodiments of the invention will be readily conceived and understood by those skilled in the art in conjunction with the description and practice of the invention disclosed herein. The descriptions and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are defined by the claims.

Claims

1. A novel intelligent bionic hydraulic carbon fiber prosthetic foot, characterized in that, include: foot; An ankle joint housing with a truncated pyramid is installed. A strain gauge for sensing vertical tension and compression and plantar dorsiflexion torque is provided between the ankle joint housing and the truncated pyramid. The bottom of the ankle joint housing is pivotally connected to the middle of the footplate connector via a sensing shaft for sensing the joint rotation angle. An electro-hydraulic damping cylinder, rotatably connected at both ends to the ankle joint housing and the front of the connecting seat, includes a cylinder body and interconnected telescopic rods, throttle valves, and support rods arranged from top to bottom along the central axis of the cylinder body; The throttle valve, located within the cylinder body cavity, has a first sealing plug extending radially outward on its outer wall, dividing the cylinder body cavity into a first cavity and a second cavity. A throttle valve sleeve is fixed axially at the bottom of the valve body. This sleeve has a through-hole connecting the first cavity and a fourth cavity within the valve body. A throttle valve core, movable vertically along the through-hole, is tightly inserted into the end of the through-hole near the fourth cavity. A throttle port connecting the second cavity and the through-hole is located on the side wall of the throttle valve sleeve. The valve body contains a coil and a coil magnet for driving the throttle valve core to move within the through-hole via electromagnetic force to change the area of ​​the throttle valve core blocking the throttle port, as well as a displacement sensor for sensing the displacement of the throttle valve core relative to the valve body along the through-hole. The control device connected to the outer wall of the cylinder includes a microprocessor and an inertial sensor for sensing motion acceleration signals and tilt angles; When the prosthetic foot performs plantar dorsiflexion, the microprocessor is used to: calculate the optimal damping coefficient based on the data sensed by the sensing shaft, strain gauge and inertial sensor respectively; obtain the actual damping coefficient based on the strain gauge equivalent model and the instantaneous speed of the throttle valve core movement; and adjust the coil current based on the PID algorithm to drive the throttle valve core movement so that the actual damping coefficient is close to the optimal damping coefficient, thereby achieving the best damping.

2. The prosthetic foot according to claim 1, characterized in that, The microprocessor is used to calculate the optimal damping coefficient based on data sensed by the sensing shaft, strain gauges, and inertial sensors, specifically including: The microprocessor uses the joint rotation angle, vertical tension and compression and plantar dorsiflexion torque, motion acceleration signal and tilt angle sensed by the sensing shaft, strain gauge and inertial sensor respectively. It uses pattern recognition or classification algorithm to identify terrain and gait stages. Based on the identified terrain and gait stages, it uses a lookup table method to retrieve the pre-stored one-to-one corresponding optimal damping coefficient.

3. The prosthetic foot according to claim 1, characterized in that, The microprocessor is used to obtain the actual damping coefficient based on the strain gauge equivalent model and the instantaneous velocity of the throttle valve core movement, specifically including: The damping force F is obtained based on the strain gauge equivalent model. The instantaneous velocity V of the throttle valve core is calculated using the numerical differentiation method based on the displacement obtained by the displacement sensor. The actual damping coefficient C is calculated using the formula C = F / V.

4. The prosthetic foot according to claim 1, characterized in that, The throttle valve also includes a piston end cap fixed to the bottom of the valve body, the bottom of the piston end cap being connected to a support rod, and the first sealing plug being disposed at the connection between the valve body and the piston end cap.

5. The prosthetic foot according to claim 1, characterized in that, The support rod also has a central hole with an open top along the axial direction. A spring with one end connected to the bottom of the support rod and the other end connected to the second sealing plug is installed in the central hole. The central hole forms a third cavity in the space between the second sealing plug and the lower end face of the piston end cap. The first oil passage is located inside the piston end cap, and the first oil passage is also connected to the third cavity via a first branch line equipped with a first check valve and a second branch line equipped with a reverse second check valve.

6. The prosthetic foot according to claim 1, characterized in that, The throttle valve core is also provided with a second oil passage along its length, one end of which is connected to the through hole and the other end of which is connected to the fourth cavity. The sidewall of the throttle valve core is provided with a first valve port and a second valve port that are respectively connected to the second oil passage along the length direction. The sidewall of the throttle valve sleeve is also provided with a third valve port that is connected to the fourth cavity. The second valve port is located between the first valve port and the third valve port along the length direction of the throttle valve core. When the throttle valve core moves up and down within the through-hole, at least one of the following remains in a connected state: First valve port and fourth cavity; The second valve port, the third valve port, and the fourth cavity; The first valve port and the second valve port are symmetrically arranged radially to the side wall of the throttle valve core, and the third valve port and the throttle port are symmetrically arranged radially to the side wall of the throttle valve sleeve.

7. The prosthetic foot according to claim 1, characterized in that, The cylinder body includes a U-shaped cylinder body with an open top, a cylinder head detachably fitted to the top opening of the cylinder body, and a lower end cap detachably fitted to the bottom of the cylinder body; and / or The valve body includes a detachably connected gate-type valve cover and a Y-shaped valve body; The valve cover and the telescopic rod are an integral structure.

8. The prosthetic foot according to claim 1, characterized in that, The top of the throttle valve core, located outside the through hole, is configured as a positioning protrusion extending radially outward. The bottom inner wall of the valve body is provided with a stop block that fits onto the throttle valve sleeve. The stop block is provided with a limiting groove to accommodate the positioning protrusion, so that when the positioning protrusion abuts downward to the limiting groove, the throttle orifice is not completely blocked by the throttle valve core, thus maintaining communication. The top of the positioning protrusion is also inserted with a positioning part along the axial direction of the cylinder body, so that when the positioning part abuts upward to the top inner wall of the valve body, the throttle valve core is still inserted in the through hole. The displacement sensor includes a magnetic ring sleeved on the positioning part and a Hall sensor fixed to the valve body.

9. The prosthetic foot according to claim 7, characterized in that, The cylinder body is also provided with an oil inlet near the lower end cover; and / or The lower part of the support rod is also provided with a through connection hole, which is used for the connecting rod to be rotatably connected to the front end of the connecting seat after passing through the connection hole.

10. The prosthetic foot according to claim 1, characterized in that, The control device also includes a communication module for communicating with mobile phones and computers; and / or The control device also includes a power management module for power supply and power management.

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