A new modular knee joint walking aid system

Abstract

The present invention discloses a novel modular knee joint walking aid system, wherein the thigh connection module and the first link module and the second link module are connected by a pin shaft, the calf connection module and the first link module and the second link module are connected by a pin shaft, the thigh connection module is connected to the thigh part of an external exoskeleton device, and the calf connection module is connected to the calf part of an external exoskeleton device, and the modules together form a four-bar linkage motion mechanism to fit the motion curve of the knee joint. The solution of the present invention accurately fits the motion curve of the human knee joint through the unique four-bar linkage motion mechanism design, reduces the force deviation during the movement process, adopts a simple rope drive and a built-in return spring ball mechanism, avoids the use of complex structures, and combines with an intelligent control system or a machine learning algorithm to automatically adjust the equipment parameters, while greatly improving the accuracy and naturalness of the knee joint assistance, while reducing the quality and cost of the equipment.

Description

Technical Field

[0001] The present invention belongs to the field of lower limb exoskeletons, and in particular relates to a novel modular knee joint walking aid system. Background Art

[0002] In the field of exoskeletons, existing knee joint walking aids rely on complex structures such as pneumatic artificial muscles for power assistance, resulting in a bloated overall structure and a large mass. This not only increases the burden on users, but also easily causes fatigue accumulation during long-term use. In addition, its fitting of the knee joint motion curve is not accurate enough, and it cannot adapt to the mechanical requirements of the human knee joint in different motion states to the greatest extent. In particular, the power assistance effect during the gait support period needs to be improved. In addition, the complex structure also makes the cost of the equipment high, limiting its wider application. At the same time, the existing technology has deficiencies in energy recovery and utilization, and cannot effectively utilize the energy during human movement, resulting in energy waste. Moreover, the personalized adaptability to different users is poor, and it cannot be flexibly adjusted according to the user's physical condition, exercise habits, etc.

[0003] For example: Patent CN202211063276.5 involves an instantaneous center adjustable variable stiffness flexible knee exoskeleton, such as Figure 1 As shown in the figure, the main components of this solution include a thigh binding connector, a thigh connector, a knee-thigh connector, a knee-center fitting four-bar mechanism, a knee-calf connector, a calf connector, a calf binding connector, a fastening airbag, and an IMU sensor. However, this knee exoskeleton solution is complex in structure and lacks comfort, and still has many problems. Summary of the Invention

[0004] In view of the above problems, the purpose of the present invention is to provide a new modular knee joint walking aid system.

[0005] The specific technical solutions for achieving the purpose of the present invention are as follows:

[0006] A novel modular knee joint walking aid system includes a thigh connection module, a calf connection module, a first link module, and a second link module;

[0007] Wherein, the thigh connection module and the first connecting rod module and the second connecting rod module are connected via a pin shaft;

[0008] The calf connection module and the first connecting rod module and the second connecting rod module are connected via a pin shaft;

[0009] The thigh connection module is connected to the thigh part of the external exoskeleton device, and the calf connection module is connected to the calf part of the external exoskeleton device;

[0010] The thigh connection module, the calf connection module, the first link module, and the second link module together form a four-link motion mechanism to fit the motion curve of the knee joint.

[0011] Furthermore, the system also includes a guide wheel module, which is connected to the second connecting rod module via bolts.

[0012] Furthermore, the guide wheel module further includes a sleeve, a guide wheel and a drive rope;

[0013] The sleeve is arranged on the guide wheel module, and a guide wheel is arranged between the second connecting rod module and the guide wheel module;

[0014] The driving rope driven by an external motor extends from the sleeve into the guide wheel module, and is connected to the calf connection module after passing through the guide wheel. The driving rope drives the extension movement of the knee joint walking aid system, thereby realizing the walking aid function.

[0015] Furthermore, an anti-fall-out ball is provided at the connection between the driving rope and the calf connection module to prevent the driving rope from falling out accidentally.

[0016] Furthermore, a reset unit is provided in the thigh connection module, and the reset unit is in contact with the second connecting rod module to provide a reset force.

[0017] Furthermore, the reset unit includes a reset spring and a rolling ball;

[0018] The return spring is arranged in the thigh connection module, one end of the return spring is fixed, and the other end is connected to the rolling ball. The rolling ball is in contact with the second connecting rod module. When the four-bar linkage mechanism moves, the second connecting rod module pushes the rolling ball to compress the return spring, generating an extension return force.

[0019] Furthermore, a cam surface is set at the contact position between the second connecting rod module and the rolling ball, and the distance from the contact point between the rolling ball and the cam surface of the second connecting rod module to the center of rotation in the direction perpendicular to the connecting rod is adjusted to adjust the joint reset torque and realize the adjustment of the reset force.

[0020] Furthermore, an electromagnetic induction coil or a piezoelectric ceramic sheet is provided at the position of the return spring, which is used to generate electrical energy by cutting the magnetic flux lines when the four-bar linkage moves, and transmit the electrical energy to an external energy storage module for storage.

[0021] Furthermore, pressure sensors and angle sensors are installed in the thigh connection module and the calf connection module to monitor the user's leg force and joint angle in real time, and automatically adjust the tension of the drive rope based on this to adapt to the physical condition and exercise habits of different users:

[0022] That is, during the support phase when the leg contacts the ground, the drive rope is tightened to provide active assistance to the knee joint; during the swing phase when the leg leaves the ground, the drive rope is loosened to reduce the knee flexion resistance:

[0023] ;

[0024] in, is the tension on the drive rope, is the maximum active driving force of the driving rope, To drive the relaxation force, is the normalized knee joint angle.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The solution of the present invention accurately fits the human knee joint motion curve through a unique four-bar linkage design, reducing the force deviation during the movement process. The use of a simple rope drive and a built-in return spring ball mechanism avoids the use of complex structures. While greatly improving the accuracy and naturalness of knee joint assistance, it also reduces the quality and cost of the equipment.

[0027] (2) The solution of the present invention ensures the stable guidance of the drive rope during movement through the ingenious fixing method of the guide wheel module and the connecting rod module, as well as the special design of the drive rope, including the anti-dropout ball at the end, thereby reducing energy loss and improving the power-assisting efficiency;

[0028] (3) The cam surface at the upper end of the connecting rod of the present invention can flexibly adjust its interaction with the rolling ball, thereby changing the degree of compression of the return spring and realizing adaptive adjustment of the return force. It can provide appropriate knee joint extension return force according to different sports scenes and user needs, thereby enhancing the versatility and comfort of the device.

[0029] (4) The solution of the present invention sets an energy recovery device in the four-bar linkage mechanism, such as a piezoelectric ceramic plate or an electromagnetic induction coil, which can effectively collect energy during human movement and convert it into electrical energy for storage and reuse, thereby reducing dependence on external energy;

[0030] (5) The solution of the present invention achieves personalized adaptation to different users by installing sensors in the connection module to monitor the user status in real time and automatically adjusting the device parameters in combination with an intelligent control system or machine learning algorithm.

[0031] The present invention will be further described below with reference to specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic structural diagram of an existing knee joint walking aid system in the background technology of the present invention.

[0033] Figure 2 This is a schematic structural diagram of the novel modular knee joint walking aid system of the present invention.

[0034] Figure 3 Schematic diagram of the structure of the first connecting rod module and the second connecting rod module in an embodiment of the present invention.

[0035] Figure 4 This is a schematic structural diagram of the guide wheel module of the present invention.

[0036] Figure 5 It is a schematic diagram of the connection between the guide wheel module and the second connecting rod module of the present invention.

[0037] Figure 6 Schematic diagram of the detailed structure of the guide wheel module in an embodiment of the present invention.

[0038] Figure 7 Schematic diagram of the reset unit structure of the present invention.

[0039] Figure 8 Schematic diagram of the adjustment principle of the reset unit of the present invention. DETAILED DESCRIPTION

[0040] Example

[0041] In order to clearly describe the technical solution and the effects achieved by the present invention, the technical solution of the present invention is clearly explained below in combination with the drawings and specific embodiments of the present invention, so that technical personnel in this field can implement the invention without performing creative work. The structure shown in the drawings is not the entire actual structure but only a part of the actual structure. It should be noted that all other embodiments made by ordinary technical personnel in this field on the basis of the embodiments of the present invention without performing creative work should fall within the scope of protection of the present invention.

[0042] The following examples are merely intended to better illustrate the present invention, but the present invention is not limited to the examples set forth herein. Therefore, those skilled in the art may make non-essential modifications to the embodiments based on the above disclosure and apply them to other examples, which remain within the scope of the present invention. Furthermore, any experimental procedures in the following examples that do not specify specific conditions should be performed according to conventional or manufacturer-recommended conditions. Unless otherwise specified, expressions in the text are used solely for differentiation and have no other meaning.

[0043] Combine Figure 2 , a new modular knee joint walking aid system, including a thigh connection module 1, a calf connection module 2, a first link module 3, and a second link module 4;

[0044] The thigh connection module 1 and the first connecting rod module 3 and the second connecting rod module 4 are connected via a pin shaft;

[0045] The calf connection module 2 is connected to the first connecting rod module 3 and the second connecting rod module 4 via a pin shaft;

[0046] That is, the thigh connection module 1, the second connecting rod module 4, and the calf connection module 2 are all designed with a rotating pin column and a pin hole, and the first connecting rod module 3 is designed with a pin hole. Based on this, they are connected to each other through pins to form a four-bar linkage.

[0047] The thigh connection module 1 is connected to the thigh part of the external exoskeleton device, and the calf connection module 2 is connected to the calf part of the external exoskeleton device;

[0048] The thigh connection module 1, the calf connection module 2, the first link module 3, and the second link module 4 together form a four-link motion mechanism to fit the motion curve of the knee joint.

[0049] In this embodiment, the first connecting rod module 3 and the second connecting rod module 4 are respectively as follows Figure 3 As shown, the first connecting rod module 3 is arc-shaped and has two rotation auxiliary holes thereon. The second connecting rod module 4 has a rotation pin at one end and two rotation auxiliary holes with a notch at the other end.

[0050] The first connecting rod module 3 and the second connecting rod module 4 respectively form a rotation pair with the thigh connection module 1 and the calf connection module 2 through their upper shafts.

[0051] Combine Figure 4 and Figure 5 The system further includes a guide wheel module 5, which is connected to the second connecting rod module 4 by bolts. In this embodiment,

[0052] The second connecting rod module 4 has a rotating pin at one end and two notched rotating secondary holes at the other end. A threaded hole and a pin hole are also provided on the upper portion. The guide wheel module 5 is designed with a corresponding bump, three bolt holes, a pin hole, a rotating shaft avoidance groove, and a wiring harness sleeve fixing hole. The second connecting rod module 4 and the guide wheel module 5 are fixed with bolts through the corresponding three threaded holes and bolt holes. The guide wheel module 5 and the second connecting rod module 4 use their corresponding pin holes to install the guide wheel to guide the drive rope and fix the sleeve. The ingenious fixing method of the guide wheel module and the connecting rod module, as well as the special design of the drive rope, including the anti-dislodgement ball at the end, ensures stable guidance of the drive rope during movement, reduces energy loss, and improves power assist efficiency.

[0053] The guide wheel module 5 further includes a sleeve 6, a guide wheel 7 and a drive rope 8;

[0054] The sleeve 6 is provided on the guide wheel module 5, and a guide wheel 7 is provided between the second connecting rod module 4 and the guide wheel module 5;

[0055] The driving rope 8 driven by an external motor extends from the sleeve 6 into the guide wheel module 5, and is connected to the calf connection module 2 via the guide wheel 7. The driving rope drives the extension movement of the knee joint walking aid system, thereby realizing the walking aid function. Here, the driving rope 8 can be connected to the thigh module or to the waist chain of the external exoskeleton mechanism. The driving rope is driven by an external motor, and the external motor can be arranged in the thigh or in multiple places such as the waist chain.

[0056] In addition, if Figure 6 As shown, an anti-fall-out ball 801 is provided at the connection between the driving rope 8 and the calf connection module 2 to prevent the driving rope 8 from falling out accidentally.

[0057] A reset unit is provided in the thigh connection module 1 , and the reset unit is in contact with the second connecting rod module 4 to provide a reset force.

[0058] Combine Figure 7 , the reset unit includes a reset spring 9 and a rolling ball 10;

[0059] The return spring 9 is arranged in the thigh connection module 1, one end of the return spring 9 is fixed, and the other end is connected to the rolling ball 10. The rolling ball 10 is in contact with the second connecting rod module 4. When the four-bar linkage mechanism moves, the second connecting rod module 4 pushes the rolling ball 10 to compress the return spring 9, generating an extension return force.

[0060] A cam surface is set at the contact position between the second connecting rod module 4 and the rolling ball 10, and the joint reset torque is adjusted by adjusting the distance from the contact point between the rolling ball 10 and the cam surface of the second connecting rod module 4 to the center of rotation in the vertical connecting rod direction to achieve adjustment of the reset force.

[0061] The principle is as follows Figure 8 As shown, r and h in the figure are known quantities in the design. r is the equivalent tangent radius between the rolling ball center and the rotation center of the second connecting rod module 4, and h is the perpendicular distance between the rolling ball center motion line and the rotation center of the connecting rod 4. Angle a is the angular position of the second connecting rod module 4;

[0062] Then when we are at point 1, we know:

[0063] d21=r*tana1,d11=h / cosa1-d21,L1=sqrtr 2 +d11 2

[0064] The angle between L1 and the straight line of motion of the center of the rolling ball is b1=a1+tan -1 d1 / r

[0065] Similarly, at point 2, d22=r*tana2, d12=h / cosa2-d22, L2=sqrtr 2 +d12 2

[0066] The angle between L2 and the straight line of motion of the center of the rolling ball is b2=a2+tan -1 d12 / r

[0067] Here the distances DS, L1, and L2 between the two points form a triangle, and its three angles are known, so DS=sqrtL1 2 +L2 2 -2*L1*L2*cos180-b2+b1;

[0068] Here the torque is the joint reduction force:

[0069] M=Fspring*h=F0+K*DS*h

[0070] Where K is the spring constant and F0 is the initial preload force;

[0071] d1 is the distance from the contact point between the rolling ball and the cam surface of the second connecting rod module 4 to the center of the rotation circle along the connecting rod direction. d1=fa is a calculable value.

[0072] If the design changes the distance from the contact point between the rolling ball at a certain position and the cam surface of the second link module 4 to the center of rotation in the vertical link direction, then the DS can be directly changed and thus the joint reset torque at this position can be changed. Based on this design, this scheme can change the compression degree of the reset spring to achieve adaptive adjustment of the reset force, and can provide appropriate knee joint extension reset force according to different sports scenarios and user needs, thereby enhancing the versatility and comfort of the equipment.

[0073] In addition, in some embodiments, an electromagnetic induction coil or a piezoelectric ceramic sheet is provided at the position of the return spring 9 to generate electrical energy by cutting the magnetic flux lines when the four-bar linkage moves, and transmit the electrical energy to an external energy storage module for storage.

[0074] The thigh connection module 1 and the calf connection module 2 are equipped with pressure sensors and angle sensors to monitor the user's leg force and joint angle in real time, and automatically adjust the tension of the drive rope based on this to adapt to the physical condition and exercise habits of different users:

[0075] That is, during the support phase when the leg contacts the ground, the drive rope is tightened to provide active assistance to the knee joint; during the swing phase when the leg leaves the ground, the drive rope is loosened to reduce the knee flexion resistance:

[0076] ;

[0077] in, is the tension on the drive rope, is the maximum active driving force of the driving rope, To drive the relaxation force, is the normalized knee joint angle.

[0078] The solution of the present invention uses a unique four-bar linkage motion mechanism design to accurately fit the human knee joint motion curve, reduce force deviation during movement, adopt a simple rope drive and built-in return spring ball mechanism, avoid the use of complex structure, and combine with intelligent control system or machine learning algorithm to automatically adjust equipment parameters, greatly improving the accuracy and naturalness of knee joint assistance while reducing equipment quality and cost.

[0079] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A modular knee joint walking aid system, characterized in that: It includes a thigh connection module (1), a calf connection module (2), a first connecting rod module (3), and a second connecting rod module (4); The thigh connection module (1) is connected to the first connecting rod module (3) and the second connecting rod module (4) via a pin shaft; The calf connection module (2) and the first connecting rod module (3) and the second connecting rod module (4) are connected via a pin shaft; The thigh connection module (1) is connected to the thigh portion of the external exoskeleton device, and the calf connection module (2) is connected to the calf portion of the external exoskeleton device; The thigh connection module (1), the calf connection module (2), the first connecting rod module (3), and the second connecting rod module (4) together form a four-link motion mechanism to fit the motion curve of the knee joint; A reset unit is provided in the thigh connection module (1), and the reset unit is in contact with the second connecting rod module (4) to provide a reset force; The reset unit comprises a reset spring (9) and a rolling ball (10); The return spring (9) is arranged in the thigh connection module (1), one end of the return spring (9) is fixed, and the other end is connected to the rolling ball (10), and the rolling ball (10) is in contact with the second connecting rod module (4). When the four-bar linkage mechanism moves, the second connecting rod module (4) pushes the rolling ball (10) to compress the return spring (9), thereby generating an extension return force; A cam surface is provided at the position where the second connecting rod module (4) and the rolling ball (10) contact each other, and the distance from the contact point between the rolling ball (10) and the cam surface of the second connecting rod module (4) to the center of the rotation circle in a direction perpendicular to the connecting rod is adjusted to thereby adjust the joint reset torque and achieve adjustment of the reset force.

2. The modular knee joint walking aid system according to claim 1, characterized in that: The system also includes a guide wheel module (5), which is connected to the second connecting rod module (4) via bolts.

3. The modular knee joint walking aid system according to claim 2, characterized in that: The guide wheel module (5) further includes a sleeve (6), a guide wheel (7) and a drive rope (8); The sleeve (6) is arranged on the guide wheel module (5), and a guide wheel (7) is arranged between the second connecting rod module (4) and the guide wheel module (5); The driving rope (8) driven by an external motor extends from the sleeve (6) into the guide wheel module (5), and is connected to the calf connection module (2) via the guide wheel (7). The driving rope drives the extension movement of the knee joint walking aid system, thereby realizing the walking aid function.

4. The modular knee joint walking aid system according to claim 3, characterized in that: An anti-fall-out ball (801) is provided at the connection between the driving rope (8) and the calf connection module (2) to prevent the driving rope (8) from falling out accidentally.

5. The modular knee joint walking aid system according to claim 1, characterized in that: A reset unit is provided in the thigh connection module (1), and the reset unit is in contact with the second connecting rod module (4) for providing a reset force.

6. The modular knee joint walking aid system according to claim 1, characterized in that: An electromagnetic induction coil or a piezoelectric ceramic sheet is provided at the position of the return spring (8), which is used to generate electric energy by cutting the magnetic flux lines when the four-bar linkage moves, and transmit the electric energy to an external energy storage module for storage.

7. The modular knee joint walking aid system according to claim 1, characterized in that: Pressure sensors and angle sensors are provided in the thigh connection module (1) and the calf connection module (2) to monitor the user's leg force and joint angle in real time, and based on this, automatically adjust the tension of the drive rope to adapt to the physical conditions and exercise habits of different users: That is, during the support phase when the leg contacts the ground, the drive rope is tightened to provide active assistance to the knee joint; during the swing phase when the leg leaves the ground, the drive rope is loosened to reduce the knee flexion resistance: ； in, is the tension on the drive rope, is the maximum active driving force of the driving rope, To drive the relaxation force, is the normalized knee joint angle.

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