Novel modularized knee joint walking aid system

Abstract

A thigh connecting module is connected with a first connecting rod module and a second connecting rod module through pin shafts, a shank connecting module is connected with the first connecting rod module and the second connecting rod module through pin shafts, the thigh connecting module is connected with the thigh part of an external exoskeleton device, and the shank connecting module is connected with the thigh part of the external exoskeleton device. The shank connecting module is connected with the shank part of an external exoskeleton device, and all the modules jointly form a four-connecting-rod movement mechanism so as to be attached to the movement curve of the knee joint. According to the scheme, the movement curve of the knee joint of the human body is precisely fitted through the unique four-connecting-rod movement mechanism design, stress deviation in the movement process is reduced, simple rope driving and a built-in reset spring ball mechanism are adopted, use of a complex structure is avoided, an intelligent control system or a machine learning algorithm is combined, and the movement accuracy of the knee joint of the human body is improved. Equipment parameters are automatically adjusted, so that the equipment quality and cost are reduced on the premise of greatly improving the precision and naturalness of knee joint assistance.

Description

Technical Field

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

[0002] In the field of exoskeletons, existing knee joint walking assistance devices mostly rely on complex structures such as pneumatic artificial muscles in terms of the assistance method, resulting in a bulky overall structure and a large mass. This not only increases the burden on users but also easily causes fatigue accumulation during long-term use. Moreover, their fitting of the knee joint movement curve is not precise enough, and they cannot adapt to the mechanical requirements of the human knee joint in different movement states to the greatest extent, especially the assistance effect during the gait support phase still needs to be improved. In addition, the complex structure also makes the cost of the device remain high, restricting its wider application. At the same time, existing technologies have deficiencies in energy recovery and utilization, unable to effectively utilize the energy during human movement, resulting in energy waste. Moreover, the personalized adaptation ability for different users is poor, and it cannot be flexibly adjusted according to the physical conditions, movement habits, etc. of users; For example: The instant center adjustable variable stiffness flexible knee joint exoskeleton involved in Patent CN202211063276.5, as Figure 1 shown, the main part of this solution includes a thigh binding connecting piece, a thigh connecting piece, a knee joint thigh connecting piece, a knee joint instant center fitting four-bar mechanism, a knee joint calf connecting piece, a calf connecting piece, a calf binding connecting piece, a fastening airbag, and an IMU sensor, etc. However, on the one hand, the knee joint exoskeleton of this solution has a complex structure and poor comfort, and there are still many problems. Summary of the Invention

[0003] Aiming at the above problems, the purpose of the present invention is to provide a novel modular knee joint walking assistance system.

[0004] The specific technical solution for achieving the purpose of the present invention is as follows: A novel modular knee joint walking assistance system includes a thigh connection module, a calf connection module, a first link module, and a second link module; Wherein, the thigh connection module is connected to the first link module and the second link module through a pin shaft; The calf connection module is connected to the first link module and the second link module through 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 the external exoskeleton device; The thigh connection module, the calf connection module, the first link module, and the second link module together form a four-bar motion mechanism to fit the movement curve of the knee joint.

[0005] Furthermore, the system also includes a guide wheel module, and the guide wheel module is connected to the second connecting rod module through bolts.

[0006] Furthermore, the guide wheel module also includes a sleeve, a guide wheel and a driving rope; 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; 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.

[0007] 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.

[0008] 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.

[0009] Further, the reset unit includes a reset spring and a rolling ball; 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, thereby generating an extension return force.

[0010] Furthermore, a cam surface is set at the contact position between the second connecting rod module and the rolling ball, and the joint resetting torque is adjusted by adjusting 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, thereby achieving adjustment of the resetting force.

[0011] Furthermore, an electromagnetic induction coil or a piezoelectric ceramic sheet is arranged at the position of the return spring, 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.

[0012] Furthermore, pressure sensors and angle sensors are provided in the thigh connection module and the calf connection module to monitor the leg force and joint angle of the user in real time, and based on this, the tension of the drive rope is automatically adjusted to adapt to the physical conditions and exercise habits of different users: That is, during the support phase when the legs touch the ground, the drive rope is tightened to provide active assistance to the knee joint; during the swing phase when the legs leave the ground, the drive rope is loosened to reduce the knee flexion impedance: ; 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.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) The solution of the present invention uses a unique four-bar linkage design to accurately fit the human knee joint motion curve and reduce the force deviation during the movement. The simple rope drive and built-in return spring ball mechanism avoid the use of complex structures, greatly improving the accuracy and naturalness of the knee joint assistance while reducing the equipment quality and cost; (2) The solution of the present invention ensures the stable guidance of the drive rope during movement, reduces energy loss and improves power efficiency through the ingenious fixing method of the guide wheel module and the connecting rod module, and the special design of the drive rope, including the anti-dropout ball at the end; (3) The cam surface at the upper end of the connecting rod of the solution of the present invention can flexibly adjust the interaction relationship with the rolling ball, thereby changing the compression degree of the reset spring, realizing adaptive adjustment of the reset force, and being able to provide appropriate knee joint extension reset force according to different sports scenes and user needs, thereby enhancing the versatility and comfort of the device; (4) The solution of the present invention sets an energy recovery device in the four-bar linkage, such as a piezoelectric ceramic plate or an electromagnetic induction coil, which can effectively collect the energy during human movement and convert it into electrical energy for storage and reuse, thereby reducing dependence on external energy; (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.

[0014] The present invention is further described below in conjunction with specific implementation modes. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of an existing knee joint walking aid system in the background technology of the present invention.

[0016] Figure 2 This is a schematic diagram of the structure of the novel modular knee joint walking aid system of the present invention.

[0017] 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.

[0018] Figure 4 It is a schematic diagram of the guide wheel module structure of the present invention.

[0019] Figure 5Schematic diagram of the connection between the guide wheel module and the second link module of the present invention.

[0020] Figure 6 Schematic diagram of the detailed structure of the guide wheel module in the embodiment of the present invention.

[0021] Figure 7 Schematic diagram of the structure of the reset unit of the present invention.

[0022] Figure 8 Schematic diagram of the adjustment principle of the reset unit of the present invention. Detailed implementation manners

[0023] Embodiment In order to clearly describe the technical solutions of the present invention and the achieved effects, the following combines the drawings of the present invention and specific embodiments to clearly illustrate the technical solutions of the present invention, so that those skilled in the art can implement the invention without creative labor. The structures shown in the drawings are not all of the actual structures but only a part of the actual structures. It should be noted that all other embodiments made by those ordinary skilled in the art without creative labor based on the embodiments of the present invention shall fall within the protection scope of the present invention.

[0024] The following listed partial embodiments are only for better illustrating the present invention, but the content of the present invention is not limited to the applied embodiments. Therefore, those skilled in the art who make non-essential modifications to the implementation manners based on the above-mentioned invention content and apply them to other embodiments are still within the protection scope of the present invention. In addition, for the experimental methods without specific conditions indicated in the following embodiments, they should be carried out according to the conventional or the conditions recommended by the manufacturer. If the expressions in the text are not specially explained, they are only used for distinction and do not have other meanings.

[0025] Combined with Figure 2 , a novel modular knee joint walking aid system, comprising a thigh connection module 1, a calf connection module 2, a first link module 3, and a second link module 4; Wherein, the thigh connection module 1 is connected to the first link module 3 and the second link module 4 through a pin shaft; The calf connection module 2 is connected to the first link module 3 and the second link module 4 through a pin shaft; That is, the thigh connection module 1, the second link module 4, and the calf connection module 2 are all designed with rotating pin shaft columns and pin holes, and the first link module 3 is designed with pin holes. Based on this, a four-bar linkage mechanism is formed through mutual pin shaft connections.

[0026] 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; 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-bar linkage mechanism to fit the movement curve of the knee joint.

[0027] In this embodiment, the first link module 3 and the second link module 4 are respectively as Figure 3 shown. The first link module 3 is arc-shaped, and two revolute pair holes are respectively provided thereon. One end of the second link module 4 is a rotating pin shaft, and two revolute pair holes are provided at the other end with a notch.

[0028] The first link module 3 and the second link module 4 respectively form revolute pairs with the thigh connection module 1 and the calf connection module 2 through the shafts thereon.

[0029] Combined with Figure 4 and Figure 5 , a guide wheel module 5 is further included in the system. The guide wheel module 5 is connected to the second link module 4 by bolts. In this embodiment, One end of the second link module 4 is a rotating pin shaft, and two revolute pair holes are provided at the other end with a notch. Threaded holes and pin holes are also respectively provided thereon. The guide wheel module 5 is designed with bumps corresponding to the second link module 4, three bolt through holes, a pin hole, a rotation shaft avoidance groove, and also a wire harness sleeve fixing hole. The second link module 4 and the guide wheel module 5 are fixed by bolts through the corresponding three threaded holes and bolt through holes. The guide wheel module 5 and the second link module 4 install guide wheels using their corresponding pin holes to realize the guiding of the drive rope and the fixing of the sleeve. Through the ingenious fixing method of the guide wheel module and the link module, and the special design of the drive rope, including the anti-disengagement ball at the end, the stable guiding of the drive rope during the movement process is ensured, the energy loss is reduced, and the assistance efficiency is improved.

[0030] 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 link module 4 and the guide wheel module 5; The drive rope 8 driven by an external motor extends from the sleeve 6 into the guide wheel module 5, passes through the guide wheel 7 and then is connected to the calf connection module 2. The extension movement of the knee joint assist system is driven by the drive rope, thereby realizing the assisting function. Here, the drive rope 8 can be connected to the thigh module or the waist chain of the external exoskeleton mechanism. The drive rope is driven by an external motor, and the external motor can be arranged at multiple places such as the thigh or the waist chain.

[0031] In addition, as Figure 6As 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.

[0032] A reset unit is disposed 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.

[0033] Combination Figure 7 , the reset unit includes 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. 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.

[0034] A cam surface is set at the contact position between the second connecting rod module 4 and the rolling ball 10, and the joint resetting 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 resetting force.

[0035] Its principle is as follows Figure 8 As shown, r and h in the figure are known quantities of 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 vertical distance between the rolling ball center motion straight line and the rotation center of the connecting rod 4. Angle a is the angular position of the second connecting rod module 4; Then when we are at point 1, we know: d21=r*tana1,d11=h / cosa1-d21,L1=sqrtr 2 +d11 2 The angle between L1 and the straight line of motion of the center of the rolling ball is b1=a1+tan -1 d1 / r Similarly, at point 2, d22=r*tana2, d12=h / cosa2-d22, L2=sqrtr 2 +d12 2 The angle between L2 and the straight line of motion of the center of the rolling ball is b2=a2+tan -1 d12 / r Here the distances between the two points DS, L1, L2 form a triangle, and its three angles are known, so DS=sqrtL1 2 +L2 2 -2*L1*L2*cos180-b2+b1; Here the torque is the joint reduction force: M = F_spring * h = F0 + K * DS * h Where K is the spring stiffness coefficient and F0 is the initial pre - tightening force; d1 is the distance along the connecting rod direction from the contact point of the rolling ball and the cam surface of the second connecting rod module 4 to the rotation center, and d1 = fa is a calculable value; If the design changes the distance perpendicular to the connecting rod direction from the contact point of the rolling ball and the cam surface of the second connecting rod module 4 at a certain position to the rotation center, then DS can be directly changed, thereby changing the joint reset torque at this position. Based on this design, this solution can change the compression degree of the reset spring, realize the adaptive adjustment of the reset force, and can provide an appropriate knee joint extension reset force according to different motion scenarios and user needs, enhancing the versatility and comfort of the device.

[0036] In addition, in some embodiments, an electromagnetic induction coil or a piezoelectric ceramic sheet is arranged at the position of the reset spring 9, which is used to generate electrical energy by cutting magnetic induction lines when the four - connecting - rod motion mechanism moves, and transmit the electrical energy to an external energy storage module for storage.

[0037] Pressure sensors and angle sensors are arranged in the thigh connection module 1 and the calf connection module 2 to real - time monitor the leg force and joint angle of the user, and automatically adjust the tension of the drive rope based on this to adapt to the physical conditions and motion habits of different users: That is, in the support phase when the leg touches the ground, the drive rope is tightened to provide active assistance to the knee joint; in the swing phase when the leg leaves the ground, the drive rope is loosened to reduce the knee joint flexion impedance: ; Wherein, is the tension on the drive rope, is the maximum active driving force of the drive rope, is the drive relaxation force, is the normalized knee joint angle.

[0038] The solution of the present invention, through the unique design of the four - connecting - rod motion mechanism, accurately fits the motion curve of the human knee joint, reduces the force deviation during the motion process, adopts a simple rope drive and an internal reset spring and ball mechanism, avoids the use of complex structures, and combines an intelligent control system or a machine learning algorithm to automatically adjust the device parameters. On the premise of greatly improving the accuracy and naturalness of the knee joint assistance, the device quality and cost are reduced at the same time.

[0039] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A novel modular knee joint walking assistance system, characterized in that, It includes a thigh connection module (1), a calf connection module (2), a first link module (3), and a second link module (4). Among them, the thigh connection module (1) is connected to the first link module (3) and the second link module (4) by a pin shaft. The calf connection module (2) is connected to the first link module (3) and the second link module (4) by a pin shaft. 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. 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-bar linkage mechanism to fit the movement curve of the knee joint.

2. The novel modular knee joint walking aid system according to claim 1, characterized in that, The system also includes a guide wheel module (5), and the guide wheel module (5) is connected to the second link module (4) by bolts.

3. The novel modular knee joint walking assistance system according to claim 2, wherein, 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 link module (4) and the guide wheel module (5). The drive rope (8) driven by an external motor extends into the guide wheel module (5) from the sleeve (6), passes through the guide wheel (7), and then is connected to the calf connection module (2). The extension movement of the knee joint assistive walking system is driven by the drive rope, thereby realizing the assistive walking function.

4. The novel modular knee joint walking assistance system according to claim 3, wherein, An anti-disengagement ball (801) is arranged at the connection position of the drive rope (8) and the calf connection module (2) to prevent the accidental disengagement of the drive rope (8).

5. The novel modular knee joint walking assistance system according to claim 1, characterized in that, A reset unit is arranged in the thigh connection module (1), and the reset unit is in contact with the second link module (4) to provide a reset force.

6. The novel modular knee joint walking assistance system according to claim 5, wherein, The reset unit includes a reset spring (8) and a rolling ball (9). The reset spring (8) is arranged in the thigh connection module (1). One end of the reset spring (8) is fixed, and the other end is connected to the rolling ball (9). The rolling ball (9) is in contact with the second link module (4). When the four-bar linkage mechanism moves, the second link module (4) pushes the rolling ball (9) to compress the reset spring (8), generating an extension reset force.

7. The novel modular knee joint walking assistance system according to claim 6, characterized in that, A cam surface is arranged at the position where the second link module (4) is in contact with the rolling ball (9). By adjusting the distance from the contact point of the rolling ball (9) and the cam surface of the second link module (4) to the vertical link direction of the rotation center, the joint reset torque is adjusted, and the adjustment of the reset force is realized.

8. The novel modular knee joint walking assistance system according to claim 6, characterized in that An electromagnetic induction coil or a piezoelectric ceramic sheet is arranged at the position of the reset spring (8) to generate electrical energy by cutting magnetic induction lines when the four-bar linkage mechanism moves, and transmit the electrical energy to an external energy storage module for storage.

9. The novel modular knee joint walking assistance system according to claim 1, characterized in that, Pressure sensors and angle sensors are arranged in the thigh connection module (1) and the calf connection module (2) to monitor the leg force and joint angle of the user in real time, and automatically adjust the tension of the drive rope based on this to adapt to the physical conditions and movement habits of different users: That is, during the stance 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 joint flexion impedance: ； Among them, is the tensile force on the drive rope, is the maximum active driving force of the drive rope, is the drive slack force, is the normalized knee joint angle.

Images