Novel intelligent bionic hydraulic carbon fiber artificial foot

Abstract

The invention provides a novel intelligent bionic hydraulic carbon fiber artificial foot, and relates to the field of artificial feet. A connecting seat; an ankle joint housing; a strain gauge; the electro-hydraulic damping cylinder comprises a cylinder body and a throttling valve assembly, and the throttling valve assembly comprises a telescopic rod, a throttling valve and a supporting rod which are connected with one another from top to bottom; the throttling valve comprises a valve body, a throttling valve sleeve is fixed to the bottom of the valve body in the axial direction of the cylinder body, a through hole is formed in the throttling valve sleeve in the axial direction of the cylinder body, a throttling valve element capable of moving up and down is inserted into the through hole, and a throttling opening is formed in the side wall of the throttling valve sleeve. The coil magnet drives the throttling valve element to move in the through hole according to generated electromagnetic force so as to change the area of the throttling opening blocked by the throttling valve element. The displacement sensor is arranged on the valve body and used for sensing the displacement amount of the throttle valve element moving up and down along the through hole relative to the valve body; the control device is arranged on the outer wall of the cylinder body and comprises an inertial sensor and a microprocessor. The artificial foot provided by the invention is simple in structure and can be actively adjusted to reach corresponding optimal damping.

Description

Technical Field

[0001] The present invention relates to the field of artificial feet, and in particular to a novel intelligent bionic hydraulic carbon fiber artificial foot. Background Art

[0002] Disabled people in my country account for 6.34% of the total population, with over 1.7 million lower limb amputees. In recent years, the number of thigh amputees has increased annually due to factors such as illness, traffic accidents, work-related injuries, and natural disasters. This not only causes inconvenience to these individuals but also places a significant burden on society. As people's living standards improve, the performance requirements for prosthetic limbs are also becoming increasingly demanding.

[0003] At present, the artificial foot products developed in China mainly include carbon fiber foot plates, carbon fiber foot plates plus hydraulic ankle joints, etc. 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. It is very inconvenient for patients to use, and it cannot achieve the bionic characteristics of the human body's natural gait.

[0004] In addition, the damping cylinder in the existing prosthetic foot generally includes a cylinder structure with two relatively sealed chambers, and 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 to complete the flow of liquid between the two chambers. The overall structure is complex; and when the liquid flows, the liquid passes through the corresponding throttle valve from one chamber to the other chamber. The flow route of the liquid is single, and the damping adjustment performance of the damping cylinder needs to be improved.

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

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

[0007] The present invention provides a novel intelligent bionic hydraulic carbon fiber prosthetic foot, which comprises:

[0008] soles of feet;

[0009] A connecting base connected to the footboard;

[0010] An ankle joint housing with a quadrangular pyramid mounted on the top, the bottom of which is pivotally connected to the middle of the connecting seat via a sensing shaft, the sensing shaft being used to sense the rotation angle of the joint;

[0011] A strain gauge is provided between the ankle joint shell and the quadrangular prism to sense vertical tension and compression and plantar dorsiflexion torque;

[0012] The electro-hydraulic damping cylinder disposed inside the ankle joint housing comprises a sealed cylinder body and a throttle valve assembly with both ends extending outside the cylinder body. The throttle valve assembly comprises a telescopic rod, a throttle valve, and a support rod that are arranged from top to bottom on the axis of the cylinder body and connected to each other. The top of the cylinder body is rotatably connected to the ankle joint housing via a horizontal pin shaft, and the bottom of the support rod is rotatably connected to the front end of the connecting seat via a horizontal connecting rod.

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

[0014] A coil and a coil magnet are provided on the inner wall of the valve body, wherein 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, so as to change the area of ​​the throttle valve core blocking the throttle port;

[0015] A displacement sensor provided to the valve body for sensing the 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 is arranged on the outer wall of the cylinder, and includes an inertial sensor for sensing motion acceleration signals and tilt angles, and a microprocessor, wherein

[0017] When the prosthetic foot performs plantar dorsiflexion movement, 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 (proportional integral differential algorithm) to drive the throttle valve core to move in the through hole, so that the actual damping coefficient is close to the optimal damping coefficient to achieve optimal damping.

[0018] According to the prosthetic foot of the present invention, through the sensing shaft, strain gauge, inertial sensor, displacement sensor, electro-hydraulic damping cylinder and control device, the corresponding optimal damping coefficient is obtained according to the identified terrain and gait stage during plantar dorsiflexion operation, and the throttle valve core is driven to move in the through hole by adjusting the coil current so that the actual damping coefficient is close to the optimal damping coefficient, thereby realizing active adjustment of the damping to achieve 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 that are interconnected and arranged from top to bottom on the axis of the cylinder body, and the throttle valve is arranged in the inner cavity of the cylinder body, so that the electro-hydraulic damping cylinder has a simple structure and a compact size; at the same time, by arranging a displacement sensor, a coil and a coil magnet, the damping size can be precisely controlled.

[0020] Optionally, the top of the throttle valve core located 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 stopper sleeved on the throttle valve sleeve, and the stopper is provided with a limiting groove for accommodating the positioning protrusion, so that when the positioning protrusion abuts downward against the limiting groove, the throttle port is not completely blocked by the throttle valve core, thereby maintaining communication;

[0021] A positioning portion is also inserted into the top of the positioning protrusion along the axial direction of the cylinder body, so that when the positioning portion abuts against the top inner wall of the valve body, the throttle valve core is still inserted into the through hole;

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

[0023] According to this solution, the positioning protrusion and stopper, on the one hand, limit the throttle valve core when it moves downward, and on the other hand, based on achieving the limit of the throttle valve core, ensure that the throttle port is not completely blocked by the throttle valve core at this time, thereby maintaining connectivity and allowing oil to flow. Furthermore, the positioning portion, on the one hand, limits the throttle valve core when it moves upward, and on the other hand, based on achieving the limit of the throttle valve core, ensure that the throttle valve core remains inserted into the through hole at this time, thereby ensuring the normal operation of the throttle valve core. Thirdly, it also serves as a mounting structure for the magnetic ring.

[0024] Additional advantages, objects, and features of the present invention will be set forth in part in the following description and will become apparent to those skilled in the art upon examination of the following or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained by the structures particularly pointed out in the description and drawings.

[0025] Those skilled in the art will understand that the purposes and advantages that can be achieved by the present invention are not limited to the above specific descriptions, and the above and other purposes that can be achieved by the present invention will be more clearly understood based on the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are intended to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention. The components in the drawings are not drawn to scale, but are merely for the purpose of illustrating the principles of the present invention. To facilitate the illustration and description of certain portions of the present invention, corresponding portions in the drawings may be exaggerated, that is, may be larger than other components in an exemplary device actually manufactured according to the present invention. In the drawings:

[0027] Figure 1 is a schematic structural diagram 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 is a schematic structural diagram of a connecting base in a prosthetic foot according to an embodiment of the present invention;

[0030] Figure 4 Schematic diagram of the internal structure of an 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 a part A in FIG; and

[0032] Figure 6 FIG. 1 is a schematic diagram of a connection frame of a partial structure of a prosthetic foot according to an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 100. Prosthetic foot;

[0035] 110. soles of feet;

[0036] 120, connecting seat; 121, first mounting hole; 122, second mounting hole; 123, third mounting hole;

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

[0038] 140. Electro-hydraulic damping cylinder;

[0039] 141, cylinder block; 1411, cylinder body; 1412, cylinder head; 1413, pin hole; 1414, lower end cover; 1415, oil inlet;

[0040] 142. Telescopic rod;

[0041] 143. Throttle valve;

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

[0043] 1432, throttle valve sleeve; 14321, through hole; 14322, throttle port; 14323, third valve port;

[0044] 1433, throttle valve core; 14331, second oil passage; 14332, first valve port; 14333, second valve port; 14334, positioning bump; 14335, positioning portion;

[0045] 144, piston end cover; 1441, first oil channel; 1442, first branch line; 1443, first one-way valve; 1444, second branch line; 1445, second one-way valve;

[0046] 145. First sealing plug;

[0047] 1461, coil; 1462, coil magnet;

[0048] 147. Magnetic ring;

[0049] 148, stopper; 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 DESCRIPTION

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

[0054] It should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0055] Ordinal numbers such as "first" and "second" cited in the present invention are merely identifiers and do not have any other meanings, such as a specific order, etc. Moreover, for example, the term "first component" itself does not imply the existence of a "second component", and the term "second component" itself does not imply the existence of a "first component".

[0056] It should be noted that the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside" and similar expressions used in this document are for illustrative purposes only and are not limiting.

[0057] The present invention provides a novel intelligent bionic hydraulic carbon fiber prosthetic foot 100. The prosthetic foot 100 can be used in the field of rehabilitation assistive devices, and can solve the problems of existing prosthetic feet such as complex structure, inability to accurately control damping, and insufficient damping adjustment.

[0058] In order to solve the above problems, the present invention provides a novel intelligent bionic hydraulic carbon fiber prosthetic foot 100. In a preferred embodiment, as Figure 1 、 Figure 2 and Figure 4 As shown, Figure 1 is a schematic structural diagram 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 The internal structure of the electro-hydraulic damping cylinder in a prosthetic foot according to one embodiment of the present invention is shown in FIG. 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 connector 120 connects the footplate 110, the ankle joint housing 131, and the electro-hydraulic damping cylinder 140. The ankle joint housing 131 is used to mount a strain gauge 134 and the electro-hydraulic damping cylinder 140. The strain gauge 134 is used to sense vertical tension and compression 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 foot plate 110 can be a conventional foot plate 110 , which can be a carbon fiber foot plate 110 .

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

[0062] An ankle joint housing 131 with a quadrangular pyramid 132 mounted on the top. The ankle joint housing 131 can be a U-shaped housing bent backward, with its top and front end being a closed structure. The bottom of the ankle joint housing 131 is rotatably connected to the middle of the connecting seat 120 via a sensing shaft 133. The sensing shaft 133 is used to sense the rotation angle of the joint. Specifically, the sensing shaft 133 may include a rotating shaft for rotational connection and an angle sensor. 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 top screw (not shown), and the axial direction can be constrained by two left and right sensing shaft covers. The top screw can be fixed to the connecting seat 120 by a thread. 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 clearance 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] The strain gauge 134 provided between the ankle joint housing 131 and the quadrangular pyramid 132 is used to sense vertical tension and pressure and plantar dorsiflexion torque.

[0064] The electro-hydraulic damping cylinder 140 disposed inside the ankle joint housing 131 includes a sealed cylinder body 141 and a throttle valve 143 assembly with both ends extending outside the cylinder body 141. The sealed cylinder body 141 may be of a one-piece type or a split type. In order 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 opening at the top, a cylinder cover 1412 detachably sleeved on the top opening of the cylinder body 1411, and a lower end cover 1414 detachably sleeved on the bottom of the cylinder body 1411. The detachable connection method may be screw connection, snap connection, or buckle connection, etc.

[0065] The throttle valve 143 assembly comprises a telescopic rod 142, a throttle valve 143, and a support rod 149, arranged from top to bottom along the axis of the cylinder 141. The top of the cylinder 141 is pivotally connected to the ankle joint housing 131 via a horizontal pin. The bottom of the support rod 149 is pivotally connected to the front end of the connecting base 120 via a horizontal connecting rod. The cylinder 141 can move up and down along the axial direction of the cylinder 141 relative to the throttle valve 143 assembly under the action of external forces.

[0066] The throttle valve 143, located within 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 to the bottom of the valve body 1431 along the axial direction of the cylinder 141. A through hole 14321 is provided in the throttle valve core 1432 along the axial direction of the cylinder 141, connecting to the fourth cavity Q4 and to the first cavity Q1 via the first oil passage 1441. A throttle valve core 1433 is tightly inserted into the end of the through hole 14321 near the fourth cavity Q4, allowing it to move up and down along the through hole 14321. In other words, the throttle valve core 1433 seals the end of the through hole 14321 near the fourth cavity Q4. A throttle port 14322 is provided on a side wall of the throttle valve core 1432 , communicating with the second cavity Q2 and the through hole 14321 .

[0067] A coil 1461 and a coil magnet 1462 are attached to the inner wall of the valve body 1431. Under the action of the coil 1461, the coil magnet 1462 generates an electromagnetic force to drive the throttle valve core 1433 to move within the through-hole 14321, thereby changing the area of ​​the throttle valve core 1433 blocking the throttle opening 14322. Specifically, by varying the excitation current of the coil 1461, the electromagnetic force generated by the coil magnet 1462 can be varied, thereby changing the position of the throttle valve core 1433 within the through-hole 14321 and, in turn, the area of ​​the throttle valve core 1433 blocking the throttle opening 14322. Specifically, during plantar flexion, the throttle valve core 1433 is controlled to block a larger area of ​​the throttle opening 14322. During dorsiflexion, the throttle valve core 1433 is controlled to block a smaller area of ​​the throttle opening 14322.

[0068] The displacement sensor provided to the valve body 1431 is used to sense the displacement of the throttle valve core 1433 relative to the valve body 1431 moving up and down along the through hole 14321.

[0069] The control device 150, mounted on the outer wall of the cylinder 141, includes an inertial sensor 151 for sensing motion acceleration signals and tilt angle, and a microprocessor. When the prosthetic foot 100 performs plantar dorsiflexion, the microprocessor is configured to: calculate the optimal damping coefficient based on data sensed by the sensing shaft 133, the strain gauge 134, and the inertial sensor 151; determine the actual damping coefficient based on the equivalent model of the strain gauge 134 and the instantaneous velocity of the throttle valve core 1433; and adjust the current in the coil 1461 using a PID algorithm (proportional-integral-differential algorithm) to drive the throttle valve core 1433 within the through hole 14321, so that the actual damping coefficient approaches the optimal damping coefficient, thereby achieving optimal damping.

[0070] Specifically, the microprocessor is based on the joint rotation angle, vertical tension and pressure, plantar dorsiflexion torque, motion acceleration signal and tilt angle sensed by the sensing shaft 133, strain gauge 134 and inertial sensor 151 respectively. After these data are processed by filtering, noise reduction and feature extraction, pattern recognition or classification algorithm can be used to identify movement intention, terrain (such as flat ground, up and down slopes, stairs) and gait stage (such as heel or toe touching and leaving the ground). Based on the identified terrain and gait stage, the pre-stored one-to-one corresponding optimal damping coefficient can be retrieved by table lookup method.

[0071] The optimal damping coefficient can be determined by using existing technologies. For example, the optimal damping coefficient can be determined by pre-establishing different working conditions (different terrains and gait phases) through experiments and training, and obtaining a mapping table corresponding to the optimal damping coefficients that match different terrains and gait phases.

[0072] The pre-stored one-to-one correspondence optimal damping coefficient is retrieved through the table lookup method. The advantages of this method are: 1. The table lookup operation has a small amount of computational complexity and can be calculated efficiently in real time; 2. The experimental data implicitly includes 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, which makes debugging convenient.

[0073] Through multimodal ankle joint sensing and electro-hydraulic damping adjustment, the ankle joint angle changes to maintain contact with the ground, resulting in a more symmetrical gait and excellent stability and safety even when walking on slopes and rough terrain. The system not only recognizes road conditions but also automatically adjusts the damping of the damping cylinder, eliminating the previous manual damping requirement and addressing the inability of passively damped prosthetic feet 100 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 the strain gauge 134 and the instantaneous speed of the throttle valve core 1433, specifically including:

[0075] Based on the equivalent model of strain gauge 134, damping force F is obtained. The instantaneous velocity V of throttle valve core 1433 is calculated using numerical differentiation based on the displacement obtained by the displacement sensor. The actual damping coefficient C is then calculated using the formula C = F / V. Alternatively, the displacement-time curve of throttle valve core 1433 can be measured through preliminary dynamic experiments, and the instantaneous velocity can be calculated using numerical differentiation. Based on the force-velocity relationship, a nonlinear characteristic curve of the damping coefficient as it changes with displacement or velocity can be obtained by fitting. During operation of prosthetic foot 100, the current actual damping coefficient can be dynamically calculated based on the real-time displacement and velocity signals of throttle valve core 1433.

[0076] Furthermore, the control device 150 may further include a communication module for communicating with a mobile phone or a computer. The control device 150 may further include a power management module for power supply and power management.

[0077] According to the above technical solution, the prosthetic foot 100 according to the present invention obtains the corresponding optimal damping coefficient according to the identified terrain and gait stage during plantar dorsiflexion operation through the sensing shaft 133, strain gauge 134, inertial sensor 151, displacement sensor, electro-hydraulic damping cylinder 140 and control device 150, and drives the throttle valve core 1433 to move in the through hole 14321 by adjusting the current of the coil 1461, so that the actual damping coefficient is close to the optimal damping coefficient, thereby realizing active adjustment of the damping to achieve the optimal damping in the corresponding terrain and gait stage, so that the electro-hydraulic damping cylinder 140 provides the most appropriate damping for the corresponding plantar flexion or dorsiflexion movement of the ankle joint. In addition, the electro-hydraulic damping cylinder 140 includes a telescopic rod 142, a throttle valve 143 and a support rod 149 that are interconnected and arranged from top to bottom on the axis of the cylinder body 141, and the throttle valve 143 is arranged in the inner cavity of the cylinder body 141, so that the electro-hydraulic damping cylinder 140 has a simple structure and a small size; at the same time, by setting a displacement sensor, a coil 1461 and a coil magnet 1462, the damping size can be precisely controlled.

[0078] refer to Figure 3 The connecting base 120 may include a base body extending forward and backward. The base body may include a first mounting hole 121 for the sensor shaft 133 (rotating shaft), a second mounting hole 122 for the connecting rod, a third mounting hole 123 for the fixing bolt, and a fourth mounting hole (not shown) connected to the second mounting hole 122 for installing a jackscrew.

[0079] To facilitate installation of the cylinder body 141, aligned pin holes 1413 for connection can be provided on the left and right sides of the cylinder cover 1412. For example, the electro-hydraulic damping cylinder 140 can be rotatably connected to the ankle joint housing 131 via a pin within the pin hole 1413. Furthermore, the cylinder body 141 can be provided with an oil inlet 1415 near the lower end cover 1414 to facilitate injection of oil into the cylinder body 141.

[0080] The top of the valve body 1431 containing the fourth cavity Q4 is connected to the telescopic rod 142. The bottom of the valve body 1431 can be connected to the piston end cover 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 cover 144. The other end of the piston end cover 144 can be connected to the support rod 149. The support rod 149 can movably extend downward from the first cavity Q1 along the axial direction of the cylinder body 141, through the bottom of the cylinder body 141, and extend to the outside. The telescopic rod 142 can movably extend upward from the second cavity Q2 along the axial direction of the cylinder body 141, through the top of the cylinder body 141, and extend to the outside.

[0081] It can be understood that the bottom of the cylinder body 141 and the 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-shaped valve body 14312 to facilitate assembly and disassembly of the valve body 1431. The valve cover 14311 and the telescopic rod 142 may be an integrated structure.

[0083] The support rod 149 can be threadedly mounted on the protrusion at the bottom of the piston end cap 144. The piston end cap 144 can also be threadedly mounted on the protrusion 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 in the axial direction. A spring 1493 is mounted within the central hole 1491, with one end connected to the bottom of the support rod 149 and the other end connected to the second sealing plug 1492. The space between the central hole 1491 and the second sealing plug 1492 and the lower end surface of the piston end cover 144 forms a third cavity Q3. When the electro-hydraulic damping cylinder 140 is in the neutral position, the spring 1493 exerts a certain preload force, causing the second sealing plug 1492 to nearly contact the lower end surface of the piston end cover 144. At this point, the third cavity Q3 is almost free of oil.

[0085] It can be understood that the center hole 1491 can also be a through hole, and its bottom can be closed by providing a sealing cover or a sealing plug.

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

[0087] The bottom of the valve body 1431 and the throttle valve core 1432 can be connected and fixed therebetween, for example, 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. A throttle opening 14322 is provided on the sidewall of the throttle valve core 1432, which is connected to the through hole 14321. The throttle opening 14322 can be connected to the second cavity Q2 via a channel defined in the valve body 1431.

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

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

[0091] Then, when the cylinder body 141 moves upward relative to the valve body 1431 under the action of an 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, a portion flows through the first branch line 1442 and the first one-way valve 1443 into the third cavity Q3, filling the third cavity Q3 with oil. This further compresses the spring 1493, preparing for its return, thus preparing for the subsequent filling of the first cavity Q1. A portion flows through the through hole 14321 and the throttle port 14322 into the second cavity Q2, filling the second cavity Q2 with oil. Another portion flows through the through hole 14321, the second oil passage 14331, and the first valve port 14332 (or alternatively, through the through hole 14321, the second oil passage 14331, the second valve port 14333, and the third valve port 14323) into the fourth cavity Q4, beginning to fill the fourth cavity Q4 with oil. Oil flows simultaneously through multiple routes in different directions, resulting in better damping adjustment performance. During this process, the speed of oil discharge from the first cavity Q1 is controlled by the actual area of ​​the throttle opening 14322 through which the oil can flow. The electromagnetic force generated by the coil 1461 and the coil magnet 1462 drives the throttle valve core 1433 downward along the through-hole 14321. The displacement sensed by the displacement sensor controls the distance the throttle valve core 1433 moves downward along the through-hole 14321, thereby controlling the area of ​​the throttle opening 14322 blocked by the throttle valve core 1433 and thereby precisely controlling the damping level.

[0092] When cylinder 141 moves downward relative to valve body 1431 under external force (e.g., during dorsiflexion), the area of ​​first cavity Q1 increases, creating a negative pressure and beginning to fill with oil. Simultaneously, second cavity Q2 begins to discharge oil, entering first cavity Q1 through orifice 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 alternatively, 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. This simultaneous flow of oil through multiple, different directions improves damping adjustment performance. In this process, the speed at which the first cavity Q1 is filled with oil is also controlled by the actual area of ​​the throttle port 14322 that can provide oil circulation. The throttle valve core 1433 can be driven to move upward along the through hole 14321 under the action of the electromagnetic force jointly generated by the coil 1461 and the coil magnet 1462. Similarly, the displacement sensed by the displacement sensor is used to control the distance that the throttle valve core 1433 moves upward along the through hole 14321, so as to continue to control the area of ​​the throttle port 14322 blocked by the throttle valve core 1433, thereby accurately controlling the damping size.

[0093] Therefore, according to the electro-hydraulic damping cylinder 140 in the artificial foot 100 of the present invention, the oil flows through multiple routes in different directions at the same time during damping adjustment, and the damping adjustment performance is better. The electro-hydraulic damping cylinder 140 of the present invention adopts a position closed-loop control that combines electromagnetic force drive and displacement feedback. The excitation current of the adjustment 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 to form a closed-loop adjustment link of "current-electromagnetic force-throttle valve core 1433 displacement". Based on the positive correlation between electromagnetic force and current and the nonlinear control mechanism of the throttle valve core 1433 displacement on the hydraulic oil flow, the electro-hydraulic damping cylinder 140 can adjust the displacement of the throttle valve core 1433 according to the damping force output as needed, thereby realizing dynamic adjustment of the damping characteristics of the electro-hydraulic damping cylinder 140 and realizing precise damping control; at the same time, the electro-hydraulic damping cylinder 140 is simple in structure and compact in size, thereby making the entire artificial foot 100 also simple in structure.

[0094] In a preferred embodiment, the top portion of the throttle valve core 1433, located outside the through hole 14321, may be provided with a positioning protrusion 14334 extending radially outward. A stopper 148 is provided on the bottom inner wall of the valve body 1431, which sleeves over the throttle valve core 1432. Stopper 148 is provided with a limiting groove 1481 that accommodates the positioning protrusion 14334. This ensures that when the positioning protrusion 14334 abuts the limiting groove 1481 downward, the throttle opening 14322 is not completely blocked by the throttle valve core 1433, thereby maintaining communication.

[0095] In this way, by setting the positioning protrusion 14334 and the stop block 148, on the one hand, the throttle valve core 1433 is limited when it moves downward, and on the other hand, on the basis of achieving the limitation of the throttle valve core 1433, it is also ensured that the throttle port 14322 is not completely blocked by the throttle valve core 1433 at this time, so as to keep the throttle port 14322 connected so that the oil can flow.

[0096] refer to Figure 4 A positioning portion 14335 may be inserted into the top of the positioning projection 14334 along the axial direction of the cylinder body 141. When the positioning portion 14335 abuts the top inner wall of the valve body 1431, the throttle valve core 1433 remains inserted into the through hole 14321. The specific type of the positioning portion 14335 is not strictly limited and may, for example, be a flower-shaped cap bolt, a T-shaped cap bolt, or a round cap bolt, inserted into the positioning projection 14334 via a threaded connection.

[0097] Regarding the displacement sensor, the specific type 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 mounted on the positioning portion 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 linear Hall sensor changes, thereby enabling the Hall sensor to accurately obtain a displacement value.

[0098] By setting the positioning portion 14335, on the one hand, the throttle valve core 1433 is limited when it moves upward. On the other hand, on the basis of achieving the limitation of the throttle valve core 1433, it is also ensured that the throttle valve core 1433 is still inserted in the through hole 14321 at this time to ensure the normal operation of the throttle valve core 1433. Thirdly, it can also serve as the installation structure of the magnetic ring 147.

[0099] Continue to refer Figure 5To ensure better oil communication between the second oil passage 14331 and the fourth cavity Q4, the sidewall of the throttle valve core 1433 may be spaced apart along its length to provide a first valve port 14332 and a second valve port 14333, each connected to the second oil passage 14331. The sidewall of the throttle valve core 1432 may 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 1433.

[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 communication 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 along the radial direction to the side wall of the throttle valve core 1433. The third valve port 14323 and the throttle port 14322 can be symmetrically arranged along the radial direction to the side wall of the throttle valve core 1432.

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

[0103] Other embodiments of the present invention will be readily apparent to those skilled in the art from the description and practice of the invention disclosed herein. The description and embodiments are intended to be exemplary only, and the true scope and spirit of the present invention are defined by the claims.

Claims

1. A new type of intelligent bionic hydraulic carbon fiber prosthetic foot, characterized by: include: soles of feet; An ankle joint housing is installed with a quadrangular pyramid, and a strain gauge for sensing vertical tension and compression and plantar dorsiflexion torque is set between the ankle joint housing and the quadrangular pyramid. The bottom of the ankle joint housing is pivotally connected to the middle of the connecting base of the foot plate via a sensing shaft for sensing the rotation angle of the joint; The electro-hydraulic damping cylinder, whose two ends are respectively connected to the ankle joint housing and the front of the connecting seat, comprises a cylinder body and a telescopic rod, a throttle valve and a support rod connected to each other and arranged on the central axis of the cylinder body from top to bottom; wherein, a throttle valve is arranged in the inner cavity of the cylinder body, and a first sealing plug is provided on the outer wall of the valve body and extends radially outward to separate the inner cavity of the cylinder body into a first cavity and a second cavity; a throttle valve sleeve is fixed to the bottom of the valve body along the axial direction of the cylinder body, and the throttle valve sleeve is provided with a through hole connected to the first cavity and the fourth cavity in the valve body along the axial direction of the cylinder body; a throttle valve core that can move up and down along the through hole is tightly inserted at one end of the through hole close to the fourth cavity, and a throttle opening connecting the second cavity and the through hole is provided on the side wall of the throttle valve sleeve; a coil and a coil magnet are provided in the valve body for driving the throttle valve core to move in the through hole by electromagnetic force to change the area of ​​the throttle opening blocked by the throttle valve core, as well as a displacement sensor for sensing the displacement of the throttle valve core relative to the valve body along the through hole; a control device connected to the outer wall of the cylinder, comprising a microprocessor and an inertial sensor for sensing motion acceleration signals and tilt angles; Among them, when the prosthetic foot performs plantar dorsiflexion movement, 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 to move, so that the actual damping coefficient is close to the optimal damping coefficient to achieve the best damping.

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

3. The artificial foot according to claim 1, wherein: The microprocessor is used to obtain an actual damping coefficient based on the strain gauge equivalent model and the instantaneous speed 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 artificial foot according to claim 1, wherein: The throttle valve further comprises a piston end cover fixed to the bottom of the valve body, the bottom of the piston end cover is connected to the support rod, and the first sealing plug is arranged at the connection between the valve body and the piston end cover.

5. The artificial foot according to claim 1, wherein: The support rod further has a central hole with an open top in the axial direction, and a spring is installed in the central hole, one end of which is connected to the bottom of the support rod and the other end is connected to the second sealing plug. The central hole is located in the space between the second sealing plug and the lower end surface of the piston end cover to form a third cavity; The first oil passage is provided in the piston end cover, and is also connected to the third cavity via a first branch line provided with a first one-way valve and a second branch line provided with a reverse second one-way valve.

6. The artificial foot according to claim 1, wherein: A second oil passage is further provided in the throttle valve core along its length, one end of the passage being connected to the through hole and the other end being connected to the fourth cavity; The side wall of the throttle valve core is provided with a first valve port and a second valve port respectively connected to the second oil passage at intervals along the length direction, and the side wall of the throttle valve sleeve is further provided with a third valve port 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 in the through hole, at least one of the following remains in a connected state: a first valve port and a fourth cavity; a second valve port, a third valve port, and a fourth cavity; The first valve port and the second valve port are symmetrically arranged to the side wall of the throttle valve core along the radial direction, and the third valve port and the throttle port are symmetrically arranged to the side wall of the throttle valve sleeve along the radial direction.

7. The artificial foot according to claim 1, wherein: The cylinder body comprises a U-shaped cylinder body with an opening at the top, a cylinder cover detachably sleeved on the top opening of the cylinder body, and a lower end cover detachably sleeved on the bottom of the cylinder body; and / or The valve body comprises a detachably connected door-type valve cover and a Y-shaped valve body; Wherein, the valve cover and the telescopic rod are an integrated structure.

8. The artificial foot according to claim 1, wherein: The top of the throttle valve core located outside the through hole is constructed as a positioning protrusion extending radially outward, and the bottom inner wall of the valve body is provided with a stopper sleeved on the throttle valve sleeve, and the stopper is provided with a limiting groove for accommodating the positioning protrusion, so that when the positioning protrusion abuts downward against the limiting groove, the throttle port is not completely blocked by the throttle valve core, so as to maintain communication; the top of the positioning protrusion is also inserted with a positioning portion along the axial direction of the cylinder body, so that when the positioning portion abuts upward against the top inner wall of the valve body, the throttle valve core is still inserted in the through hole; Wherein, the displacement sensor includes a magnetic ring sleeved on the positioning part and a Hall sensor fixed to the valve body.

9. The artificial foot according to claim 7, characterized in that The cylinder body is further provided with an oil inlet near the lower end cover; and / or A through connecting hole is also provided at the lower portion of the support rod, for the connecting rod to pass through the connecting hole and then be rotatably connected to the front end of the connecting seat.

10. The artificial foot according to claim 1, wherein The control device further includes a communication module for communicating with a mobile phone or a computer; and / or The control device further comprises a power management module for supplying power and managing power.

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