A power-assisted gas-liquid coupled damping cylinder for knee joint prosthesis and control method thereof

Abstract

The present invention discloses a power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis and a control method thereof, the damping cylinder comprising: an above-knee receiving cavity fixing piece; a hydraulic cylinder body; a piston rod, one end of which is coaxially arranged in the hydraulic cylinder body, and the other end of which passes through the upper end of the hydraulic cylinder body and is hinged to the above-knee receiving cavity fixing piece; a limit clamping seat, which is fixedly installed at the lower end of the hydraulic cylinder body; a cylinder body, the upper end of which is coaxially connected with the lower end of the hydraulic cylinder body, and the lower end of which is provided with a cylinder hinge hole and is hinged to the prosthesis; wherein a compensation hole is axially opened on the limit clamping seat, and the lower end of the hydraulic cylinder body and the upper end of the cylinder body are connected through the compensation hole; a gas piston, which is arranged in the cylinder body; an inflation valve, which is arranged at the lower end of the cylinder body, and the inflation valve is connected to the cylinder body.

Description

Technical Field

[0001] The present invention relates to the technical field of rehabilitation assistive devices, and in particular to an assisted gas-liquid coupled damping cylinder for a knee joint prosthesis and a control method thereof. Background Art

[0002] Based on sample data from specific groups, tens of thousands of people are forced to undergo amputation surgery every year due to war, earthquakes, traffic accidents and diseases. Wearing a prosthesis is the only viable solution for them to restore their ability to walk. The mechanisms and components of passive knee prostheses are highly compatible with the biomechanics of normal walking, lightweight, quiet and energy-efficient; however, these passive devices cannot fully simulate the natural movement of the limbs under all conditions and have difficulty adapting to different walking speeds or different types of terrain and walking patterns; semi-active prostheses are significantly lighter and quieter. At the same time, these semi-active devices can provide the wearer with the ability to adjust the impedance of the knee joint, thereby controlling the walking speed; however, existing damping cylinders can often only adjust the damping generated when the wearer uses it, but cannot track and control the trajectory; in addition, when amputees wear existing prostheses with damping cylinders as elastic elements, if they face scenes such as slopes or stairs, they need to use energy input to complete the task; however, active prostheses are often heavier than passive prostheses, which will bring higher metabolic costs to the wearer. Summary of the invention

[0003] The purpose of the present invention is to provide a power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis, which has a simple and compact structure, low energy consumption, and can stably and quickly adjust the damping.

[0004] The present invention also provides a control method for an assistive gas-liquid coupled damping cylinder for a knee joint prosthesis, which performs secondary correction based on the adjustment of the damping cylinder, effectively reducing the energy consumption of the prosthesis and improving the assisting effect.

[0005] The technical solution provided by the present invention is:

[0006] A power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis, comprising:

[0007] Above knee socket fixation;

[0008] Hydraulic cylinder;

[0009] A piston rod, one end of which is coaxially arranged in the hydraulic cylinder body, and the other end of which passes through the upper end of the hydraulic cylinder body and is hinged to the above-knee receiving cavity fixing member;

[0010] A limit clamping seat, which is fixedly mounted on the lower end of the hydraulic cylinder body;

[0011] A cylinder body, the upper end of which is coaxially connected to the lower end of the hydraulic cylinder body, and the lower end of which is provided with a cylinder hinge hole for hinged connection with the prosthesis;

[0012] Wherein, a compensation hole is opened in the axial direction on the limit clamping seat, and the lower end of the hydraulic cylinder body and the upper end of the cylinder body are connected through the compensation hole;

[0013] A gas piston disposed in the cylinder body;

[0014] A charging valve is arranged at the lower end of the cylinder body, and the charging valve is communicated with the cylinder body.

[0015] Preferably, it also includes:

[0016] A regulating valve, which is a conical groove valve, and the conical groove valve is connected to the interior of the hydraulic cylinder body through a main oil line pipe and a regulating valve connecting pipe;

[0017] The regulating motor is connected to the lower end of the conical slot valve to drive the conical slot valve to rotate and change the cross-sectional area of ​​the conical slot valve communicating with the interior of the hydraulic cylinder body.

[0018] Preferably, the tapered groove valve is provided with a drain port at the upper end and a tapered groove in the middle; the small-diameter end of the tapered groove is connected to the regulating valve connecting pipe, and the large-diameter end of the tapered groove is connected to the main oil circuit pipe through the drain port.

[0019] Preferably, it also includes:

[0020] A hydraulic pump connecting piece connected to the outer wall of the hydraulic cylinder body and communicating with the interior of the hydraulic cylinder body;

[0021] a gear pump, which is arranged at the lower end of the hydraulic pump connecting piece and is connected to the interior of the hydraulic cylinder body through the hydraulic pump connecting piece;

[0022] A hydraulic pump motor is connected to the gear pump.

[0023] Preferably, it also includes:

[0024] A battery compartment, which is arranged on the prosthesis;

[0025] An STM32 single-chip microcomputer, which is provided on the prosthesis;

[0026] An IMU inertial sensor integrated inside the above-knee socket fixture;

[0027] An angle encoder is arranged at one end of the prosthesis close to the above-knee socket fixing piece;

[0028] A driver, which is arranged on the prosthesis and connected to the regulating motor and the hydraulic pump motor through a wire;

[0029] A pressure sensor fixedly connected to the bottom of the knee joint calf tube;

[0030] Among them, the IMU inertial sensor, the angle encoder, the driver and the pressure sensor are all connected to the STM32 microcontroller.

[0031] Preferably, a control method for a power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis comprises:

[0032] The actual angle of the knee joint is recorded by an angle encoder, and the error value between the actual angle of the knee joint and the desired angle of the knee joint is calculated. The error value is compared with the threshold set by the system. If the error value is greater than the threshold set by the system, the adjustment motor is driven by the driver to perform secondary correction, and the hydraulic pump motor is driven to perform forward or reverse oil suction movement. The hydraulic oil pushes the piston rod to adjust the position so that the knee joint reaches the desired angle of the knee joint.

[0033] Preferably, it also includes:

[0034] The hydraulic pump motor runs continuously to continuously pump the hydraulic oil above the piston into the area below the piston rod, thereby generating an upward thrust to assist movement.

[0035] The beneficial effects of the present invention are:

[0036] The power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis provided by the present invention has a simple and compact structure, is light in weight, has low energy consumption, can stably and quickly adjust the damping, and has precise damping adjustment.

[0037] The control method of the power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis provided by the present invention performs secondary correction on the basis of the adjustment of the damping cylinder to realize an operation strategy in which the damping cylinder adjustment is mainly and the hydraulic pump assistance is auxiliary. It can adjust the position and track the trajectory when the knee joint prosthesis swings, effectively reducing the energy consumption of the prosthesis and improving the assistance effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic structural diagram of the power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis according to the present invention.

[0039] Figure 2 It is a cross-sectional view of the hydraulic cylinder body described in the present invention.

[0040] Figure 3 It is a half-section view of the connecting sleeve described in the present invention.

[0041] Figure 4 It is a structural schematic diagram of the piston rod described in the present invention.

[0042] Figure 5 It is a schematic structural diagram of the position limiting holder described in the present invention.

[0043] Figure 6 It is a cross-sectional view of a hydraulic cylinder assembly without a piston rod inside according to the present invention.

[0044] Figure 7 It is a cross-sectional view of the cylinder assembly described in the present invention.

[0045] Figure 8 It is a schematic diagram of the drain port structure of the present invention.

[0046] Fig. 9 It is a schematic diagram of the tapered groove structure described in the present invention.

[0047] Fig.10 It is a structural schematic diagram of the regulating valve assembly described in the present invention.

[0048] Fig.11 This is a flow diagram of the hydraulic oil in the conical groove during the compression movement of the power-assisted gas-liquid coupled damping cylinder for the knee joint prosthesis described in the present invention.

[0049] Fig.12 This is a cross-sectional view of the hydraulic oil flow direction at the small-diameter end of the tapered groove valve during the compression movement of the gas-liquid coupled damping cylinder for the knee joint prosthesis described in the present invention.

[0050] Fig.13 This is a flow diagram of the hydraulic oil at the drain port during compression movement of the assisted gas-liquid coupled damping cylinder for the knee joint prosthesis described in the present invention.

[0051] Fig.14 This is a cross-sectional view of the hydraulic oil flow direction at the large-diameter end of the tapered groove valve during the compression movement of the gas-liquid coupled damping cylinder for the knee joint prosthesis described in the present invention.

[0052] Fig.15 This is a flow diagram of the hydraulic oil in the conical groove during the extension movement of the power-assisted gas-liquid coupled damping cylinder for the knee joint prosthesis described in the present invention.

[0053] Fig.16 It is a cross-sectional view of the flow direction of hydraulic oil at the small-diameter end of the tapered groove valve during the extension movement of the gas-liquid coupled damping cylinder for the knee joint prosthesis described in the present invention.

[0054] Fig.17 This is a flow diagram of the hydraulic oil at the drain port of the assisted gas-liquid coupled damping cylinder for the knee joint prosthesis during extension movement according to the present invention.

[0055] Fig.18 It is a cross-sectional view of the flow direction of hydraulic oil at the large-diameter end of the tapered groove valve during the extension movement of the gas-liquid coupled damping cylinder for the knee joint prosthesis described in the present invention.

[0056] Fig.19 This is an exploded view of the hydraulic pump assembly according to the present invention.

[0057] Fig. 20 It is a schematic structural diagram of the hydraulic pump connecting piece described in the present invention.

[0058] Fig.21 This is an exploded view of the power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis according to the present invention.

[0059] Fig. 22 This is a schematic diagram of the structure of the installation position and control drive assembly of the power-assisted gas-liquid coupled damping cylinder for the knee joint prosthesis described in the present invention.

[0060] Fig.23 This is a flow diagram of the internal hydraulic oil during compression movement of the gas-liquid coupled damping cylinder for the knee joint prosthesis described in the present invention.

[0061] Fig.24 This is a flow diagram of the internal hydraulic oil during the extension movement of the gas-liquid coupled damping cylinder for the knee joint prosthesis described in the present invention.

[0062] Fig.25 This is a flow chart of the control method of the power-assisted gas-liquid coupled damping cylinder for the knee joint prosthesis described in the present invention.

[0063] Figure numerals: hydraulic cylinder assembly 100; hydraulic cylinder body 110; hydraulic cylinder inner cavity 111; piston rod hole 112; sealing groove 113; upper guide port 114; lower guide port 115; main oil circuit pipe 116; regulating valve hole 117; regulating valve connecting pipe 117a; upper connecting hole 118; lower connecting hole 119; connecting sleeve 120; center through hole 121; isolation key 122; first oil port 123; second oil port 124; upper pump port 125; lower pump port 126; upper cavity 127; lower cavity 128; piston rod 130; rod piston 131; hinge 132; first cavity 133; second cavity 134; limit clamp 140; compensation hole 141. Cylinder assembly 200; cylinder body 210; cylinder hinge hole 211; gas piston 220; third cavity 221; fourth cavity 222; charging valve 230; charging valve port 231; charging valve cap 232. Regulating valve assembly 300; conical groove valve 310; valve stem 311; conical groove 312; drain port 313; valve base 314; connecting shaft hole 314a; first thrust bearing 320; second thrust bearing 330; regulating motor 340; regulating motor base 341. Hydraulic pump assembly 400; hydraulic pump connector 410; upper oil port 411; lower oil port 412; first pump diversion channel 413; second pump diversion channel 414; first pump connection hole 415; second pump connection hole 416; gear pump 420; first pump port 421; second pump port 422; coupling hole 423; hydraulic pump motor 430. Control drive assembly 500; IMU inertial sensor 510; angle encoder 520; STM32 single chip microcomputer 530; driver 540; pressure sensor 550; battery compartment 560; sealing Gly ring 610; wear ring 620. DETAILED DESCRIPTION

[0064] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0065] like Figure 1 As shown, the present invention provides a power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis, which includes: a hydraulic cylinder assembly 100, a cylinder assembly 200, a regulating valve assembly 300, and a hydraulic pump assembly 400.

[0066] The cylinder assembly 200, the regulating valve assembly 300, and the hydraulic pump assembly 400 are respectively connected to the lower end, front side, and rear side of the hydraulic cylinder assembly 100; the upper end of the hydraulic cylinder assembly 100 is hinged to the above-knee socket fixture, and the lower end is connected to the upper end of the cylinder assembly 200 by threads; the inner wall of the lower end of the hydraulic cylinder assembly 100 is provided with threads, and the outer wall of the upper end of the cylinder assembly 200 is provided with threads, and the hydraulic cylinder assembly 100 is connected to the cylinder assembly 200 by threads; the lower end of the cylinder assembly 200 is hinged to the prosthesis; the regulating valve assembly 300 is connected to the front side of the hydraulic cylinder assembly 100; the hydraulic pump assembly 400 is connected to the rear side of the hydraulic cylinder assembly 100.

[0067] The hydraulic cylinder assembly 100 realizes passive extension and passive flexion movements with adjustable damping through the regulating valve assembly 300; the cylinder assembly 200 is used for storing and releasing energy during the movement of the knee prosthesis, and compensating for part of the volume of the hydraulic oil lost when the piston rod 130 is pressed down; the regulating valve assembly 300 drives the conical groove valve 310 to rotate by the adjusting motor 340 to adjust the opening size of the conical groove valve 310 facing the oil circuit, thereby adjusting the damping of the hydraulic cylinder assembly 100 to realize passive extension and passive flexion of the knee joint; the hydraulic pump assembly 400 drives the gear pump 420 through the hydraulic pump motor 430 to drive the hydraulic pump assembly 400.

[0068] like Figure 2As shown, the hydraulic cylinder assembly 100 includes: a hydraulic cylinder body 110, which forms a hydraulic cylinder cavity 111 inside after being connected with a limit clamp 140, for installing a connecting sleeve 120; a piston rod hole 112 is provided on the top of the hydraulic cylinder body 110, and the piston rod 130 passes through the piston rod hole 112 and is connected to the hydraulic cylinder assembly 100, and the piston rod 130 reciprocates in the hydraulic cylinder assembly 100; a sealing groove 113 is provided inside the piston rod hole 112, for installing a sealing ring 610 between the piston rod 130 and the hydraulic cylinder assembly 100; a main oil line pipe 116 is provided on the front side of the hydraulic cylinder cavity 111; a regulating valve hole 117 is provided at the lower end of the main oil line pipe 116, for installing the regulating valve assembly 300; the inner side of the end of the regulating valve hole 117 A thread is provided, and the regulating motor seat 341 is connected to the regulating valve hole 117 through a thread, so that the hydraulic cylinder assembly 100 and the regulating valve assembly 300 are connected together; an upper guide port 114 and a lower guide port 115 are provided in front of the hydraulic cylinder inner cavity 111, and an upper connecting hole 118 and a lower connecting hole 119 are provided at the rear, which are used to fix the connecting sleeve 120 and the hydraulic pump connecting piece 410; a regulating valve connecting pipe 117a is provided between the regulating valve hole 117 and the hydraulic cylinder body 110, and the hydraulic cylinder inner cavity 111 is connected to the main oil circuit pipe 116 through the upper guide port 114, and the hydraulic cylinder inner cavity 111 is connected to the regulating valve hole 117 through the main oil circuit pipe 116, the upper guide port 114, the lower guide port 115 and the regulating valve connecting pipe 117a.

[0069] like Figure 3 As shown, the hydraulic cylinder assembly 100 also includes: the connecting sleeve 120 is coaxially arranged in the hydraulic cylinder inner cavity 111; an isolation key 122 is provided in the middle of the outer wall of the connecting sleeve 120, and the connecting sleeve 120 is fixedly connected to the hydraulic cylinder body 110 through the isolation key 122; the connecting sleeve 120 is provided with a central through hole 121 for installing the piston rod 130, and the piston rod 130 reciprocates in the central through hole 121; an upper pump port 125 and a lower pump port 126 are provided at the rear of the connecting sleeve 120, and a first oil port 123 and a second oil port 124 are provided in the front of the connecting sleeve 120, and the first oil port 123 and the second oil port 124 are both three parallel circular holes.

[0070] like Figure 4As shown, the hydraulic cylinder assembly 100 also includes: one end of the piston rod 130 is coaxially arranged in the central through hole 121, reciprocating in the central through hole 121, and the other end passes through the upper end of the hydraulic cylinder body 110 and is hinged to the above-knee receiving cavity fixing piece; the piston rod 130 includes: a rod piston 131, one end of which is coaxially arranged in the central through hole 121, and the other end passes through the piston rod hole 112 and is connected to the hydraulic cylinder body 110; the sealing grid ring 610 and the wear-resistant ring 620 are provided between the rod piston 131 and the hydraulic cylinder body 110, and between the rod piston 131 and the connecting sleeve 120; the hinge 132 is arranged at the end of the other end of the rod piston 131, is threadedly connected to the rod piston 131, and is hinged to the above-knee receiving cavity fixing piece.

[0071] A first cavity 133 is formed inside the hydraulic cylinder body 110 , inside the connecting sleeve 120 , and above the rod piston 131 . A second cavity 134 is formed inside the connecting sleeve 120 and above the rod piston 131 .

[0072] like Figure 5 As shown, the hydraulic cylinder assembly 100 also includes: the limit clamp 140 is fixedly installed at the lower end of the hydraulic cylinder body 110, and a compensation hole 141 is axially opened on the limit clamp 140, and the lower end of the hydraulic cylinder body 110 and the upper end of the cylinder body 210 are connected through the compensation hole 141, so as to compensate for the part of the hydraulic oil entering the third cavity 221 through the compensation hole 141 when the piston rod 130 is pressed downward; the upper part of the limit clamp 140 is fixedly connected to the lower end of the connecting sleeve 120, and is used for limiting the connecting sleeve 120; the lower part of the limit clamp 140 is fixedly connected to the upper end of the cylinder body 210, and is used for limiting the cylinder body 210 and isolating the gas piston 220.

[0073] like Figure 6 As shown, the cavity formed between the outer side of the connecting sleeve 120 and the inner side of the hydraulic cylinder body 110 is divided into an upper cavity 127 and a lower cavity 128 by the isolating key 122; the upper cavity 127 is formed by the inner side of the hydraulic cylinder body 110, the outer side of the connecting sleeve 120 and above the isolating key 122, and the lower cavity 128 is formed by the inner side of the hydraulic cylinder body 110, the outer side of the connecting sleeve 120 and below the isolating key 122; the upper cavity 127 is connected with the first cavity 133 through the first oil port 123, and the lower cavity 128 is connected with the second cavity 134 through the second oil port 124.

[0074] like Figure 7As shown, the cylinder assembly 200 includes: the cylinder body 210, the interior of which is a cylinder cavity for installing the gas piston 220, the gas piston 220 is arranged in the cylinder cavity, and reciprocates in the cylinder cavity, and the sealing ring 610 and the wear-resistant ring 620 are arranged between the gas piston 220 and the cylinder body 210; the upper end of the cylinder body 210 is fixedly connected to the lower part of the limit card seat 140, and is coaxially connected to the lower end of the hydraulic cylinder body 110 through a thread, and the lower end is provided with a cylinder hinge hole 211, which is hinged to the prosthesis; the inner side of the cylinder body 210 is connected to the upper part of the gas piston 220 The third cavity 221 is formed, and a fourth cavity 222 is formed inside the cylinder body 210 and below the gas piston 220; an air filling valve 230 is arranged at the front side of the lower end of the cylinder body 210, and the air filling valve 230 is connected to the fourth cavity 222, and the cylinder assembly 200 can be inflated and deflated through the air filling valve 230; an air filling valve cap 232 is arranged on the outer side of the air filling valve port 231, and the outer wall of the air filling valve port 231 is provided with threads, and the air filling valve cap 232 is connected to the air filling valve port 231 by threads; the air filling valve cap 232 is used to protect the air filling valve 230.

[0075] like Figure 8-9 As shown, the regulating valve assembly 300 includes: a regulating valve, which is the tapered groove valve 310, and the tapered groove valve 310 includes: a valve stem 311, which is used to fix the tapered groove valve 310; a drain port 313, which is arranged at the upper end of the valve stem 311, and is used for the flow of hydraulic oil on the tapered groove valve 310, and a tapered groove 312, which is arranged in the middle of the valve stem 311, and the small-diameter end of the tapered groove 312 is narrow and shallow, and the large-diameter end is wide and deep, and the cross-section of the tapered groove 312 is circular, and the unfolded shape is conical; the tapered groove The large-diameter end of 312 is connected to the drain port 313, the small-diameter end of the tapered groove 312 is connected to the regulating valve connecting pipe 117a, and the large-diameter end of the tapered groove 312 is connected to the main oil circuit pipe 116 through the drain port 313. The damping is adjusted by changing the cross-sectional area of ​​the tapered groove 312 and the lower guide port 115, and the cross-sectional area and the rotation angle of the tapered groove valve 310 are in a quadratic function relationship; a valve base 314 is provided at the lower end of the valve stem 311, and a connecting shaft hole 314a is provided in the valve base 314.

[0076] like Fig.10As shown, the regulating valve assembly 300 also includes: a first thrust bearing 320 and a second thrust bearing 330, which are respectively arranged on the upper and lower sides of the valve base 314; the conical groove valve 310 is arranged in the regulating valve hole 117, and the valve stem 311 passes through the first thrust bearing 320 and rotates in the main oil pipe 116; the upper side of the first thrust bearing 320 is fixedly connected to the top of the regulating valve hole 117, and the lower side is fixedly connected to the upper side of the valve base 314; the regulating motor 340 is provided with the regulating motor seat 341 on its upper part, and the regulating motor 340 is connected to the lower end of the conical groove valve 310 to drive the conical groove valve 310 to rotate, and the conical groove 312 is changed by the conical groove 312 and the conical groove 312. The damping is adjusted by adjusting the cross-sectional area of ​​the regulating valve connecting pipe 117a; a fixed threaded hole is provided inside the regulating motor seat 341, and the regulating motor 340 is threadedly connected to the regulating motor seat 341 through the fixed threaded hole; a thread is provided on the outer wall of the regulating motor seat 341, so that the regulating motor 340 is threadedly connected to the lower end of the regulating valve hole 117; the upper side of the second thrust bearing 330 is fixedly connected to the lower side of the valve base 314, and the lower side is fixedly connected to the upper side of the regulating motor seat 341; the regulating motor 340 passes through the adjusting motor seat 341 and the second thrust bearing 330 and is connected to the connecting shaft hole 314a, so that the regulating motor 340 is fixedly connected to the conical slot valve 310.

[0077] like Figure 11-14 As shown, when the piston rod 130 moves from top to bottom, the hydraulic oil in the second cavity 134 passes through the second oil port 124 and then passes through the lower cavity 128, the lower guide port 115, and the regulating valve connecting pipe 117a to enter the regulating valve hole 117, and then passes through the narrow side of the tapered groove valve 310, the wide side of the tapered groove valve 310, and the drain port 313 to enter the main oil circuit pipe 116, and then passes through the upper guide port 114, the upper cavity 127, and the first oil port 123 to enter the first cavity 133.

[0078] like Figure 15-18 As shown, when the piston rod 130 moves from bottom to top, the hydraulic oil in the first cavity 133 passes through the first oil port 123 and then passes through the upper cavity 127 and the upper guide port 114 in turn to enter the main oil circuit pipe 116, and then passes through the drain port 313, the wide side of the tapered groove valve 310, and the narrow side of the tapered groove valve 310 in turn to enter the regulating valve hole 117, and then passes through the regulating valve connecting pipe 117a, the lower guide port 115, the lower cavity 128, and the second oil port 124 in turn to enter the second cavity 134.

[0079] The minimum cross-sectional area of ​​the travel of the conical slot valve 310 and the lower guide port 115 is always semicircular. The damping is adjusted by changing the cross-sectional area of ​​the conical slot valve 310 and the lower guide port 115. The cross-sectional area and the rotation angle of the conical slot valve 310 are in a quadratic function relationship, which facilitates damping calculation and precise damping control.

[0080] like Fig.19 As shown, the hydraulic pump assembly 400 includes: the hydraulic pump connecting member 410, which is connected to the outer wall of the rear side of the hydraulic cylinder body 110 and is connected to the interior of the hydraulic cylinder body 110; the gear pump 420, which is connected to the lower end of the hydraulic pump connecting member 410 and is connected to the interior of the hydraulic cylinder body 110 through the hydraulic pump connecting member 410; the gear pump 420 is provided with a coupling hole 423 at the rear, a first pump port 421 is provided at the right front side, and a second pump port 422 is provided at the left front side; the hydraulic pump motor 430 is connected to the gear pump 420 through the coupling hole 423; the gear pump 420 is driven by the hydraulic pump motor 430, thereby driving the hydraulic pump cylinder assembly 400.

[0081] like Fig. 20 As shown, the hydraulic pump connecting member 410 is provided with an upper oil port 411 and a lower oil port 412 on the front side, a first pump guide channel 413 is provided on the right side of the rear interior, a second pump guide channel 414 is provided on the left side of the rear interior of the hydraulic pump connecting member 410, a first pump connecting hole 415 is provided on the right side of the bottom of the hydraulic pump connecting member 410, and a second pump connecting hole 416 is provided on the left side of the bottom of the hydraulic pump connecting member 410; the upper oil port 411, the first pump guide channel 413, the first pump connecting hole 415, the first pump port 421, the lower oil port 412, the second pump guide channel 414, the second pump connecting hole 416, and the second pump port 422 are connected one by one; the upper pump port 125 is connected to the upper oil port 411 through the upper connecting hole 118, and the lower pump port 126 is connected to the lower oil port 412 through the lower connecting hole 119.

[0082] like Fig.21 As shown, the hydraulic cylinder assembly 100 is connected to the cylinder assembly 200 through threads, the regulating valve assembly 300 is connected in the regulating valve hole 117 of the hydraulic cylinder assembly 100, and the upper oil port 411 is connected to the upper pump port 125, and the lower oil port 412 is connected to the lower pump port 126, so that the hydraulic pump assembly 400 is connected to the hydraulic cylinder assembly 100 together.

[0083] like Fig. 22As shown, the control drive assembly 500 is connected to the upper end of the hydraulic cylinder assembly 100 and the lower end of the cylinder assembly 200 to determine the motion state of the prosthesis and then output a signal to drive the adjustment motor 340 and the hydraulic pump motor 430 .

[0084] The control drive component 500 is used to determine the motion state output signal of the prosthesis, so as to drive the adjustment motor 340 and the hydraulic pump motor 430; the control drive component 500 includes: a battery compartment 560, which is arranged above the front side of the prosthesis, and the battery compartment 560 contains batteries to power the prosthesis; an IMU inertial sensor 510, which is fixedly connected to the above-knee socket fixture and is used to measure the phase angle between the thigh and the vertical direction; the IMU inertial sensor 510 is integrated inside the above-knee socket fixture; an angle encoder 520, which is arranged at one end of the prosthesis close to the above-knee socket fixture, and is used to measure and record the actual angle of the knee joint; the STM32 single-chip microcomputer 530 is installed on the front side of the battery compartment 560, and is used to process the signals of various sensors; the driver 540 is installed at the lower front side of the prosthesis, and is used to provide driving signals for the adjusting motor 340 and the hydraulic pump motor 430. The driver 540 uses a multi-axis driver, and the driver 540 is connected to the adjusting motor 340 and the hydraulic pump motor 430 through wires; the pressure sensor 550 is fixedly connected to the bottom of the calf tube of the knee joint, and is used to measure the ground reaction force exerted on the prosthesis, wherein the IMU inertial sensor 510, the angle encoder 520, the driver 540 and the pressure sensor 550 are all connected to the STM32 microcontroller 530.

[0085] like Fig.23 As shown, when the knee joint is flexed, the damping cylinder begins to compress, the piston rod 130 moves downward, and the hydraulic oil under the piston rod 130 begins to flow. Under the push of the piston rod 130, the hydraulic oil enters the regulating valve hole 117 from the second cavity 134 through the second oil port 124, the lower cavity 128, the lower guide port 115, and the regulating valve connecting pipe 117a, and then is adjusted through the regulating valve assembly 300, and enters the main oil circuit pipe 116 through the narrow side of the tapered groove valve 310, the wide side of the tapered groove valve 310, and the drain port 313 in turn. After adjustment, it enters the first cavity 133 through the upper guide port 114, the upper cavity 127, and the first oil port 123 in turn.

[0086] In order to compensate for the missing volume of the piston rod 130, part of the hydraulic oil in the second cavity 134 flows into the third cavity 221 through the compensation hole 141 of the limit clamp 140. The gas piston 220 moves downward under the pressure of the hydraulic oil, compressing the gas in the fourth cavity 222 to accumulate energy.

[0087] like Fig.24 As shown, when the knee joint swings, the energy accumulated after the gas in the fourth cavity 222 is compressed begins to be released, the gas piston 220 moves upward, the piston rod 130 moves upward under the action of the thrust, and the human knee joint begins to swing; the hydraulic oil in the third cavity 221 flows into the second cavity 134 through the compensation hole 141 of the limit clamp 140; when the piston rod 130 moves from bottom to top, the hydraulic oil in the first cavity 133 flows into the second cavity 134 through the first oil port 1 23, then enters the main oil circuit pipe 116 through the upper cavity 127 and the upper guide port 114 in turn, and then is adjusted by the regulating valve assembly 300, and enters the regulating valve hole 117 through the drain port 313, the wide side of the tapered groove valve 310, and the narrow side of the tapered groove valve 310 in turn, and after adjustment, it enters the second cavity 134 through the regulating valve connecting pipe 117a, the lower guide port 115, the lower cavity 128, and the second oil port 124 in turn.

[0088] The flexion and swing of the knee joint are directly controlled by the wearer. After adjustment by the regulating valve assembly 300, the minimum throttling area of ​​the entire oil circuit changes, the flow rate of the oil circuit circulation changes, and the corresponding damping also changes, thereby controlling the speed and trajectory of the flexion and extension of the knee joint; the program is written in advance and burned into the STM32 microcontroller 530; before the prosthesis is used, the cylinder body 210 needs to be inflated through the inflation valve 230, similar to the inflation of a bicycle tire.

[0089] Through the joint action of the hydraulic cylinder assembly 100 and the air cylinder assembly 200, the damping can be adjusted quickly and stably. The combined system can output a large thrust with stability. This structure can give full play to the advantages of the hydraulic cylinder 110 in terms of output force, and at the same time utilize the rapid response characteristics of the air cylinder 210, so that the system has both powerful power and flexible controllability, can achieve lower energy consumption, can be flexibly adjusted according to different work requirements, and is easy to maintain.

[0090] like Fig.25 As shown, a control method for a power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis is provided, which includes: walking correction mode:

[0091] Step 1, the IMU inertial sensor 510 measures the phase angle between the thigh and the vertical direction, and inputs the phase angle into the STM32 single chip microcomputer 530;

[0092] Step 2: construct a phase variable in the STM32 single-chip microcomputer 530, and obtain a unique virtual constraint function of knee joint motion based on the experimental results of healthy people's tests to generate a desired angle of the knee joint; the STM32 single-chip microcomputer 530 outputs a position signal according to the desired angle of the knee joint, and the driver 540 receives the position signal from the STM32 single-chip microcomputer 530 to drive the regulating motor 340 to work, and the regulating motor 340 drives the conical slot valve 310 to adjust the damping in the gait cycle;

[0093] Step 3, the angle encoder 520 records the actual angle of the knee joint, and compares it with the expected angle of the knee joint, calculates the error value, constructs an error function in the STM32 single-chip microcomputer 530, and the STM32 single-chip microcomputer 530 outputs a corresponding position signal according to the error function. The driver 540 receives the position signal from the STM32 single-chip microcomputer 530, performs a correction, and drives the adjustment motor 340 to work again, fine-tunes the position of the conical slot valve 310, and then controls the damping of the prosthetic joint movement, so that the error function tends to 0, so that the system satisfies the virtual constraint relationship, reaches the expected angle of the knee joint, and realizes the coordinated movement or stillness of the prosthesis wearer;

[0094] Step 4, the angle encoder 520 records the actual angle of the knee joint again, and compares it with the expected angle of the knee joint, calculates a new error value, and compares the error value with the threshold value set by the system. If the error value is less than the threshold value set by the system, no secondary correction is required; if the error value is greater than the threshold value set by the system, the adjustment motor 340 performs secondary correction and at the same time the hydraulic pump assembly 400 is added to the secondary correction process, the driver 540 receives the position signal from the STM32 single-chip microcomputer 530, drives the adjustment motor 340 to perform secondary correction through the driver, and drives the hydraulic pump motor 430 to perform forward or reverse oil suction movement, and the hydraulic oil pushes the piston rod 130 to adjust the position so that the knee joint reaches the expected angle of the knee joint; the pressure sensor 550 measures the ground reaction force exerted on the prosthesis, and uses the actual angle of the knee joint recorded by the angle encoder 520 and the phase angle of the thigh and the vertical direction measured by the IMU inertial sensor 510 as variables for judging the walking state switching function of the wearer, so as to switch the speed and mode.

[0095] During this period, the angle encoder 520 will record the actual angle of the knee joint and compare it with the expected angle of the knee joint. If the knee joint angle at a certain moment of movement still does not reach the predetermined position after the damping adjustment, the hydraulic pump assembly 400 will start and perform a secondary correction simultaneously with the adjustment motor 340; if the actual angle of the knee joint is less than the expected angle of the knee joint, refer to Fig.23, the gear pump 420, driven by the hydraulic pump motor 430, sucks the hydraulic oil from the second cavity 134 into the gear pump 420 through the lower pump port 126, the second pump guide channel 414, the lower oil port 412 and the second pump port 422 in sequence, and then the hydraulic oil is pumped out from the first pump port 421, and enters the first cavity 133 through the first pump guide channel 413, the upper oil port 411 and the upper pump port 125 in sequence. Under the action of the hydraulic pump assembly 400, the hydraulic oil gives the piston rod 130 a downward thrust, fine-tuning the piston rod 130 to reach the desired position, so that the prosthesis can reach the desired angle of the knee joint; if the actual angle of the knee joint is greater than the desired angle of the knee joint, please refer to Fig.24 Driven by the hydraulic pump motor 430, the gear pump 420 sucks the hydraulic oil from the first cavity 133 into the gear pump 420 through the upper pump port 125, the first pump guide channel 413, the upper oil port 411 and the first pump port 421 in sequence, and then the hydraulic oil is pumped out from the second pump port 422, and enters the second cavity 134 through the second pump guide channel 414, the lower oil port 412 and the lower pump port 126 in sequence. Under the action of the hydraulic pump assembly 400, the hydraulic oil gives the piston rod 130 an upward thrust, fine-tunes the piston rod 130 to reach the desired position, and the prosthesis can reach the desired angle of the knee joint.

[0096] Special power-assisting mode: For example, when going uphill or up stairs, the hydraulic pump motor 430 drives the gear pump 420 to run continuously, and the hydraulic oil in the first cavity 133 is continuously pumped into the second cavity 134, generating an upward thrust to assist the movement.

[0097] Control process in walking correction mode: the regulating valve assembly 300 and the hydraulic pump assembly 400 simultaneously regulate the damping of the prosthetic joint movement; the phase angle between the thigh and the vertical direction is measured by the IMU inertial sensor 510 , construct the phase variable , set the virtual constraint function , generate the desired angle of the knee joint according to the virtual constraint function First, the STM32 microcontroller 530 in the control drive assembly 500 controls the knee joint angle according to the desired Output position signal , the driver 540 receives a position signal from , driving the regulating motor 340 to work, the regulating motor 340 drives the conical slot valve 310 to adjust the damping in the gait cycle; then, setting the error function to , the actual knee joint angle is recorded by the angle encoder 520 and the desired knee angle By comparison, the STM32 microcontroller 530 in the control drive component 500 outputs a corresponding position signal according to the error function , the driver 540 receives a position signal from The driver 540 receives the position signal from the STM32 microcontroller 530 , make a correction, drive the regulating motor 340 to work again, fine-tune the position of the conical slot valve 310, and then control the damping of the prosthetic joint movement, so that the error function tends to 0, making the system satisfy the virtual constraint relationship , to achieve the desired knee angle , to achieve coordinated movement or stillness of the prosthesis wearer; the actual knee joint angle is recorded again by the angle encoder 520 and the desired knee angle A comparison is made to generate a new error value, and the relationship between the error value and the threshold value set by the system is determined. If the error value is less than the threshold value set by the system, no secondary correction is required; if the error value is still greater than the threshold value set by the system, the regulating motor 340 performs secondary correction while the hydraulic pump assembly 400 is added to the secondary correction process, and the driver 540 receives the position signal from the STM32 microcontroller 530. , driving the hydraulic pump assembly 400 to perform forward or reverse oil suction movement, and the hydraulic oil pushes the piston rod 130 to adjust the position so that the knee joint reaches the desired knee joint angle .

[0098] in: is the phase angle between the thigh and the vertical direction; is the phase variable; is a virtual constraint function; is the desired angle of the knee joint; is the actual angle of the knee joint; is the error function; is the position signal.

[0099] In the walking correction mode, the regulating valve assembly 300 and the hydraulic pump assembly 400 simultaneously adjust the damping of the prosthetic joint during movement, the angle encoder 520 records the actual angle of the knee joint and compares it with the expected angle of the knee joint to generate an error value. In order to make the error function tend to 0, the regulating valve assembly 300 performs a correction, and the regulating valve assembly 300 and the hydraulic pump assembly 400 perform a secondary correction at the same time, so that the error function is less than the system threshold, so that the system satisfies the virtual constraint relationship, realizes the coordinated movement or stillness of the prosthesis wearer, and makes the knee joint reach the expected angle; the pressure sensor 550 measures the ground reaction force exerted on the prosthesis, and together with the knee joint angle recorded by the angle encoder 520 and the phase angle between the thigh and the vertical direction measured by the IMU inertial sensor 510, they are used as variables for judging the wearer's walking state switching function, so as to switch the speed and mode.

[0100] The power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis of the present invention comprises a hydraulic cylinder assembly, an air cylinder assembly, a regulating valve assembly, and a hydraulic pump assembly. The above-mentioned components are all integrated inside the damping cylinder, and have a simple and compact structure, a small size, a light weight, and low energy consumption, and can stably and quickly adjust the damping. Among them, the regulating valve assembly adopts a conical groove valve design, which makes the damping adjustment more precise and easy to control.

[0101] The control method of the power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis of the present invention performs secondary correction on the basis of the adjustment of the damping cylinder, and has an accurate trajectory, comfortable use, and high safety. It realizes an operation strategy of mainly using damping adjustment and supplemented by hydraulic pump power assistance, and can perform position regulation and trajectory tracking control when the knee joint prosthesis swings, effectively reducing the energy consumption of the prosthesis, improving the power-assisting effect, and extending the endurance time.

[0102] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis, characterized in that: include: above knee socket fixation; Hydraulic cylinder; A communicating sleeve, which is coaxially disposed in the hydraulic cylinder body; An isolation key, which is arranged in the middle of the outer wall of the connecting sleeve; Wherein, the connecting sleeve is fixedly connected to the hydraulic cylinder body via the isolation key; A piston rod, one end of which is coaxially arranged in the connecting sleeve, and the other end of which passes through the upper end of the hydraulic cylinder body and is hinged to the above-knee receiving cavity fixing member; A limit clamping seat, which is fixedly mounted on the lower end of the hydraulic cylinder body; A cylinder body, the upper end of which is coaxially connected to the lower end of the hydraulic cylinder body, and the lower end of which is provided with a cylinder hinge hole for hinged connection with the prosthesis; Wherein, a compensation hole is opened in the axial direction on the limit clamping seat, and the lower end of the hydraulic cylinder body and the upper end of the cylinder body are connected through the compensation hole; A gas piston disposed in the cylinder body; A charging valve, which is arranged at the lower end of the cylinder body, and the charging valve is connected to the cylinder body; A regulating valve assembly and a hydraulic pump assembly, which are arranged on the side of the hydraulic cylinder body and communicated with the interior of the hydraulic cylinder body; A control drive assembly, which is mounted on the hydraulic cylinder body and is used to drive the regulating valve assembly and the hydraulic pump assembly to adjust the damping; The regulating valve assembly comprises: The regulating valve is a conical groove valve, which is connected to the inside of the hydraulic cylinder body through a main oil line pipe and a regulating valve connecting pipe; a drain port is provided at the upper end of the conical groove valve, and a conical groove is provided in the middle; the small-diameter end of the conical groove is connected to the regulating valve connecting pipe, and the large-diameter end of the conical groove is connected to the main oil line pipe through the drain port; an adjusting motor connected to the lower end of the conical slot valve to drive the conical slot valve to rotate and change the cross-sectional area of ​​the conical slot valve in communication with the interior of the hydraulic cylinder body; The hydraulic pump assembly comprises: A hydraulic pump connecting piece connected to the outer wall of the hydraulic cylinder body and communicating with the interior of the hydraulic cylinder body; a gear pump, which is arranged at the lower end of the hydraulic pump connecting piece and is connected to the interior of the hydraulic cylinder body through the hydraulic pump connecting piece; A hydraulic pump motor is connected to the gear pump.

2. The power-assisted gas-liquid coupled damping cylinder for knee joint prosthesis according to claim 1, characterized in that: The connecting sleeve is provided with a central through hole, and the piston rod reciprocates in the central through hole; an upper pump port and a lower pump port are provided at the rear of the connecting sleeve; a first oil port and a second oil port are provided at the front of the connecting sleeve, and the first oil port and the second oil port are both three parallel circular holes.

3. The power-assisted gas-liquid coupled damping cylinder for knee joint prosthesis according to claim 2, characterized in that: An upper connecting hole and a lower connecting hole are arranged at the rear of the hydraulic cylinder body.

4. The power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis according to claim 3, characterized in that: An upper oil port and a lower oil port are provided on the front side of the hydraulic pump connecting piece, a first pump flow guide channel is provided on the right side of the rear interior, a second pump flow guide channel is provided on the left side of the rear interior of the hydraulic pump connecting piece, a first pump connecting hole is provided on the right side of the bottom of the hydraulic pump connecting piece, and a second pump connecting hole is provided on the left side of the bottom of the hydraulic pump connecting piece; a coupling hole is provided at the rear of the gear pump, a first pump port is provided on the right side of the front, and a second pump port is provided on the left side of the front; wherein, the hydraulic pump motor is connected to the gear pump through the coupling hole; the upper oil port, the first pump flow guide channel, the first pump connecting hole, the first pump port, the lower oil port, the second pump flow guide channel, the second pump connecting hole, and the second pump port are connected one by one; the upper pump port is connected to the upper oil port through the upper connecting hole, and the lower pump port is connected to the lower oil port through the lower connecting hole.

5. The power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis according to claim 1, characterized in that: The control drive component comprises: A battery compartment, which is arranged on the prosthesis; An STM32 single-chip microcomputer, which is provided on the prosthesis; An IMU inertial sensor integrated inside the above-knee socket fixture; An angle encoder is arranged at one end of the prosthesis close to the above-knee socket fixing piece; A driver, which is arranged on the prosthesis and connected to the regulating motor and the hydraulic pump motor through a wire; A pressure sensor fixedly connected to the bottom of the knee joint calf tube; Among them, the IMU inertial sensor, the angle encoder, the driver and the pressure sensor are all connected to the STM32 microcontroller.

6. A control method for a power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis, used to control the power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis as claimed in claim 5, characterized in that: include: Step 1, the IMU inertial sensor measures the phase angle between the thigh and the vertical direction, and inputs the phase angle into the STM32 single chip microcomputer; Step 2: constructing a phase variable in the STM32 single-chip microcomputer, and using the experimental results based on healthy people's tests to obtain a unique virtual constraint function of the knee joint motion, to generate a desired angle of the knee joint; the STM32 single-chip microcomputer outputs a position signal according to the desired angle of the knee joint, the driver receives the position signal from the STM32 single-chip microcomputer, drives the regulating motor to work, and the regulating motor drives the conical slot valve to adjust the damping in the gait cycle; Step 3, the angle encoder records the actual angle of the knee joint, and compares it with the expected angle of the knee joint, calculates the error value between the actual angle of the knee joint and the expected angle of the knee joint, constructs an error function in the STM32 single-chip microcomputer, and the STM32 single-chip microcomputer outputs a corresponding position signal according to the error function. The driver receives the position signal from the STM32 single-chip microcomputer, performs a correction, drives the adjustment motor to work again, fine-tunes the position of the tapered slot valve, and then controls the damping of the prosthetic joint motion, so that the error function tends to 0, so that the system satisfies the virtual constraint relationship, reaches the expected angle of the knee joint, and realizes coordinated movement or stillness of the prosthesis wearer; Step 4. The angle encoder records the actual angle of the knee joint again and compares it with the expected angle of the knee joint, calculates a new error value between the actual angle of the knee joint and the expected angle of the knee joint, and compares the error value with a threshold value set by the system. If the error value is greater than the threshold value set by the system, the driver drives the adjustment motor for secondary correction, and drives the hydraulic pump motor to perform forward or reverse oil suction movement. The hydraulic oil pushes the piston rod to adjust the position so that the knee joint reaches the expected angle of the knee joint.

7. The control method of the power-assisted gas-liquid coupled damping cylinder for a knee joint prosthesis according to claim 6, characterized in that: Also includes: The hydraulic pump motor runs continuously to continuously pump the hydraulic oil above the piston into the area below the piston rod, thereby generating an upward thrust to assist movement.

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