Motion matching knee joint exoskeleton robot

Abstract

The invention relates to a motion matching knee joint exoskeleton robot, and relates to the technical field of medical instruments, the motion matching knee joint exoskeleton robot comprises a binding device, the binding device comprises a thigh ring sleeve and a shank ring sleeve, a thigh rod is mounted on the thigh ring sleeve, a shank rod is mounted on the shank ring sleeve, a gear joint is arranged between the thigh rod and the shank rod, and the gear joint is connected with the thigh ring sleeve. The gear joint comprises a large gear part and a small gear part, the large gear part is installed on the side, facing the shank rod, of the thigh rod, the small gear part is installed on the side, facing the thigh rod, of the shank rod, the small gear part and the large gear part are meshed with each other, a power piece is installed on the thigh rod, and a connecting rod is installed on the power piece. The power piece drives the connecting rod to rotate, a transmission rod is hinged to the connecting rod, one end of the transmission rod is hinged to the connecting rod, the other end of the transmission rod is hinged to the shank rod, and the effect of improving the adaptation degree of the exoskeleton machine and the knee joint is achieved.

Description

Technical Field

[0001] This application relates to the field of medical devices, and particularly to a motion-matching knee exoskeleton robot. Background Art

[0002] An exoskeleton robot is a wearable mechanical system that integrates disciplines such as mechanics, electricity, control, human-computer interaction, and biomechanics, and has been applied in industrial, military, and medical fields. The exoskeleton robot can provide assistance to the wearer to improve human physical fitness, can help patients with gait disorders and orthopedic diseases perform movement rehabilitation, can help patients with postoperative rehabilitation, and can also assist the elderly with declining motor abilities in daily activities.

[0003] Currently, most exoskeleton robots design the knee joint part as a single-degree-of-freedom fixed-axis rotation structure. However, the knee joint has complex movements. The movement mode of the knee joint is not a simple flexion and extension movement, but a complex multi-degree-of-freedom movement mode that combines flexion and extension, rolling, sliding, lateral displacement, and axial rotation. It includes both rolling and sliding in the sagittal plane, and the instantaneous center of rotation (ICR) of the tibia and femur is not fixed but moves along a "J"-shaped trajectory. The single-degree-of-freedom knee exoskeleton has poor movement coordination with the human knee joint, and the knee joint is overly constrained. When worn, it will not only cause human-machine misalignment and discomfort during wearing, but also cause biomechanical abnormalities of the knee joint, ultimately leading to joint injuries. Summary of the Invention

[0004] In order to improve the adaptability between the exoskeleton robot and the knee joint, this application provides a motion-matching knee exoskeleton robot.

[0005] A motion-matching knee exoskeleton robot provided by this application adopts the following technical solutions:

[0006] A motion-matching knee exoskeleton robot includes a binding device. The binding device includes a thigh loop and a calf loop. A thigh rod is installed on the thigh loop, and a calf rod is installed on the calf loop. A gear joint is provided between the thigh rod and the calf rod. The gear joint includes a large gear part and a small gear part. The large gear part is installed on the side of the thigh rod facing the calf rod, and the small gear part is installed on the side of the calf rod facing the thigh rod. The small gear part and the large gear part mesh with each other. A power component is installed on the thigh rod, and a connecting rod is installed on the power component. The power component drives the connecting rod to rotate. A transmission rod is hingedly provided on the connecting rod. One end of the transmission rod is hinged to the connecting rod, and the other end is hingedly provided on the calf rod.

[0007] By adopting the above technical solution, the large gear part and the small gear part are provided to make the thigh rod and the calf rod rotate around the centers of both the large gear plate and the small gear plate, so as to realize the rotation with two centers, making the rotation between the thigh rod and the calf rod more fitting to the movement of the knee joint of the human leg and improving the adaptability of the exoskeleton robot to the knee joint.

[0008] Optionally, a gear connecting rod is arranged between the large gear part and the small gear part, and the large gear part and the small gear part are respectively rotatably arranged at both ends of the gear connecting rod.

[0009] Optionally, a mounting platform is installed on the thigh rod, and the motor is installed on the thigh rod through the mounting platform.

[0010] Optionally, a limiting ring is arranged on the mounting platform, a limiting port is opened on the limiting ring, and the connecting rod is rotatably arranged in the limiting port.

[0011] Optionally, a plurality of fixing plates are detachably arranged on both the thigh rod and the calf rod, a plurality of thigh rings and calf rings are respectively arranged on the thigh rod and the calf rod, and the thigh rings are installed on the thigh rod through the fixing plates, and the calf rings are installed on the calf rod through the fixing plates.

[0012] Optionally, a plurality of mounting holes are evenly opened along the length direction of both the thigh rod and the calf rod, and the fixing plates are detachably installed on the thigh rod or the calf rod by bolts in cooperation with the mounting holes.

[0013] Optionally, both the thigh ring and the calf ring include a coil and a strap, the coil is fixedly installed on the fixing plate, and the strap is wrapped outside the coil.

[0014] Optionally, a layer of gasket is fixedly arranged inside the coil.

[0015] In summary, the present application includes at least one of the following beneficial technical effects:

[0016] 1. By arranging the large gear part and the small gear part, the thigh rod and the calf rod rotate around the centers of both the large gear plate and the small gear plate, so as to realize the rotation with two centers, making the rotation between the thigh rod and the calf rod more fitting to the movement of the knee joint of the human leg and improving the adaptability of the exoskeleton robot to the knee joint;

[0017] 2. Using the matlab nlinfit non - linear fitting function to fit the instantaneous center of motion of the knee joint into a circle, and formulating the sizes of the large gear plate and the small gear plate by analyzing the radius of the fitted circle as a parameter, so as to further improve the adaptability of the exoskeleton robot to the knee joint;

[0018] 3. The setting of the limit ring restricts the movement range of the exoskeleton within the normal range of the human joint, ensuring that the rotation range of the exoskeleton does not exceed the movement limit of the human joint, avoiding accidental injuries to the human body caused by exoskeleton failures, and enhancing the safety of the exoskeleton;

[0019] 4. The fixing plate is detachably installed on the thigh rod or calf rod through bolts and mating mounting holes, and by installing the fixing plate at different positions, it can be suitable for users with different leg lengths;

[0020] 5. The setting of the gasket can make the wrapping of the coil more comfortable. Brief Description of the Drawings

[0021] Figure 1 is a schematic diagram of the overall structure of the embodiment of the present application.

[0022] Figure 2 is an exploded view of the overall structure of the embodiment of the present application.

[0023] Figure 3 is a schematic diagram of the structure of the gear joint of the embodiment of the present application.

[0024] Figure 4 is a schematic diagram of the gear-five link mechanism of the embodiment of the present application.

[0025] Figure 5 is a fitting diagram of the instantaneous center of knee joint movement in the present application.

[0026] In the figure, 1. Binding device; 101. Thigh loop; 102. Calf loop; 1011. Coil; 1012. Binding strap; 2. Thigh rod; 3. Calf rod; 4. Gear joint; 41. Large gear part; 411. Large mounting plate; 412. Large gear plate; 42. Small gear part; 421. Small mounting plate; 422. Small gear plate; 5. Power component; 6. Connecting rod; 7. Transmission rod; 8. Gear link; 9. Rotating shaft; 10. Bearing; 11. Mounting table; 12. Limit ring; 13. Limit port; 14. Fixing plate; 15. Mounting hole; 16. Gasket. Detailed Description of the Embodiment

[0027] The following will further illustrate the present application in conjunction with the appended Figures 1-5 drawings and specific embodiments:

[0028] First of all, it should be noted here that in the description of this application, when terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and other orientation words appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings. It is only for the convenience of description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation to this application; in addition, when terms such as "first", "second", "third" and other numerical quantifiers appear, they are only for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in this application, unless otherwise clearly specified and limited, when terms such as "installation", "connection", "linkage" appear, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, an interference fit, a transition fit and other limiting connections, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium; therefore, for those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0029] An embodiment of the present application discloses a motion-matching knee exoskeleton robot. Referring to Figure 1 , Figure 2 and Figure 3 , it includes a binding device 1. The binding device 1 includes a thigh loop 101 and a calf loop 102. A thigh rod 2 is installed on the thigh loop 101, and a calf rod 3 is installed on the calf loop 102. A gear joint 4 is arranged between the thigh rod 2 and the calf rod 3. The gear joint 4 includes a large gear part 41 and a small gear part 42. The large gear part 41 includes a large mounting plate 411 and a large gear plate 412. The large mounting plate 411 is detachably installed on one end of the thigh rod 2 facing the calf rod 3 through bolts. The large gear plate 412 is fixed on the large mounting plate 411. The large gear plate 412 is a fan-shaped gear plate. The small gear part 42 includes a small mounting plate 421 and a small gear plate 422. The small mounting plate 421 is detachably installed on one end of the calf rod 3 facing the thigh rod 2 through bolts. The small gear plate 422 is fixed on the small mounting plate 421. The small gear plate 422 is a semi-circular gear plate. The small gear plate 422 and the large gear plate 412 mesh with each other. A power component 5 is installed on the thigh rod 2. In this embodiment, the power component 5 is selected as a motor. A connecting rod 6 is installed on the power component 5. The power component 5 drives the connecting rod 6 to rotate. A transmission rod 7 is hingedly arranged on the connecting rod 6. One end of the transmission rod 7 is hinged to the connecting rod 6, and the other end is hingedly arranged on the calf rod 3; through the setting of the large gear part 41 and the small gear part 42, the thigh rod 2 and the calf rod 3 take the centers of the large gear plate 412 and the small gear plate 422 as the rotation points, so as to realize the rotation of two centers, making the rotation between the thigh rod 2 and the calf rod 3 more fitting the movement of the knee joint of the human leg and improving the adaptability of the exoskeleton machine to the knee joint.

[0030] Referring toFigure 2 , Figure 3 and Figure 4 , a gear link 8 is provided between the large gear portion 41 and the small gear portion 42. In this embodiment, two gear links 8 are provided on both sides of the large gear portion 41 and the small gear portion 42 in the thickness direction. Two rotating shafts 9 are provided between the two gear links 8. In this embodiment, the rotating shaft 9 is selected as a bolt, and the bolt can not only serve as the rotating shaft 9 but also cooperate with a nut to install the two gear links 8 between the large gear portion 41 and the small gear portion 42. The two rotating shafts 9 are respectively provided near both ends of the gear link 8 in the length direction. Bearings 10 are sleeved on the rotating shafts 9. The large gear portion 41 and the small gear portion 42 are respectively rotatably provided at both ends of the gear link 8 through the bearings 10. One end of the rotating shaft 9 of the gear link 8 passes through the center of the large gear plate 412, and the other end of the rotating shaft 9 of the gear link 8 passes through the center of the small gear plate 422. The gear link 8 provides a connection between the large gear portion 41 and the small gear portion 42, reducing the probability of their mutual separation. At the same time, the thigh rod 2, the calf rod 3, the gear link 8, the transmission rod 7, the connecting rod 6 and the gear joint 4 form a gear-five link mechanism. The formula for calculating the degree of freedom of the mechanism is F = 3n - Pl - Ph (where F is the degree of freedom; n is the number of movable members; Pl is the number of lower pair constraints; Ph is the number of higher pair constraints). It can be seen that the degree of freedom of the five link mechanism is 2. The five link mechanism itself has 2 degrees of freedom and requires two prime movers to have a definite motion, which does not meet the motion conditions. However, after introducing a pair of gear higher pairs, the degree of freedom is 1, which just meets the motion requirements driven by a DC motor at this time. The introduced gear profile can be used to simulate the instantaneous center of motion of the knee joint; The instantaneous center of motion of the knee joint refers to Figure 5As shown, the matlab nlinfit non - linear fitting function is used to fit it into a circle. The radius of the fitted circle is 71.74 mm, and 72 mm is taken in actual use. Then, a gear is designed with the diameter of the fitted circle as the pitch circle radius of the gear. This gear is used as the bionic gear joint 4 to approximately simulate the change trajectory of the instantaneous center of the knee joint movement; among the basic parameters of the gear, the module and the number of teeth jointly determine the size and strength performance of the gear. The module is the ratio of the pitch between two adjacent teeth on the gear to π. The module is one of the indicators to measure the size of the gear. The size of the gear increases with the increase of the module, and the load - bearing capacity also becomes stronger as the module increases. The number of teeth refers to the number of teeth on the gear. The more teeth there are, the larger the size of the gear, but the load - bearing capacity is not necessarily stronger. The pitch circle diameter is the diameter of the circle where the center connection line of two adjacent teeth on the gear is located. The product of the module and the number of teeth is the pitch circle diameter of the gear. The relationship among the three is shown in the formula d = m * z (where: d is the pitch circle diameter; m is the gear module; z is the number of teeth of the gear). In this embodiment, the pitch circle radius of the bionic gear joint 4 has been determined to be 72 mm, so only one of the parameters of the module and the number of teeth needs to be determined. Since the value of the module is related to the load - bearing capacity of the gear, the generally most commonly used module range is between 2 and 5. Therefore, the module of 3 is selected, and the number of teeth of the bionic gear is calculated to be 48. The bionic gear is designed with these parameters. Then, according to the gear meshing principle of equal module and equal pressure angle, the appropriate number of teeth is selected according to the appropriate size. Finally, the determined number of teeth is 20 and the module is 3. The gear - five - link mechanism is composed of a pair of gears and five links. The gears are used to simulate the change of the rotation center of the knee joint, and the five links are respectively used as the thigh rod 2, the calf rod 3, the gear link 8, and two power rods. After the design of the bionic gear joint 4 is completed, the lengths of each link need to be determined. In a conventional four - link knee exoskeleton, the instantaneous center of the common four - link mechanism is often used to simulate the rotation center of the knee joint. This brings higher requirements for the determination of the lengths of the four links. It is necessary to strictly calculate the lengths of each link to make the instantaneous center of the mechanism coincide or be similar to the rotation center of the knee joint. The design of the four - link mechanism is relatively complex and requires more work to solve and optimize the lengths of the four links.In the gear-five-bar linkage mechanism, the rotational instantaneous center of the knee joint is simulated by the tooth profiles of the meshing gears. The lengths of the five bars only need to consider the overall dimensions of the exoskeleton. Therefore, only the overall dimensions of the exoskeleton need to be used to determine the appropriate lengths, which simplifies the design process of the bar lengths and makes the simulation of the instantaneous center trajectory of the knee joint movement more efficient and intuitive. To facilitate the structural design and ensure that the overall dimensions of the whole machine are not too large, the length from the hinge point on the large gear plate 412 to one end of the connecting rod 6 for installing the power component 5 on the thigh bar 2 is finally determined to be 134 mm. The length from the hinge point on the small gear plate 422 to the hinge point of the calf bar 3 and the transmission bar 7 is 45 mm. The length of the connecting rod 6 is 60 mm, the length of the transmission bar 7 is 236 mm, and the length of the gear link 8 is 102 mm. It should be noted that the length of the gear link 8 is determined as the center distance length of the meshing of the two gears after the bionic gear joint 4 is designed.

[0031] Referring to Figure 1 and Figure 2 , a mounting platform 11 is installed on the thigh bar 2, and the motor is installed on the thigh bar 2 through the mounting platform 11. A limiting ring 12 is provided on the mounting platform 11, and a limiting port 13 is opened on the limiting ring 12. The connecting rod 6 is rotatably arranged in the limiting port 13. Since the movement of the human joint is within a certain range, during the structural design process of the knee joint exoskeleton, the movement range of the human knee joint should be actually considered. The function of the limiting ring 12 is to limit the movement range of the exoskeleton within the normal range of the human joint, ensure that the rotation range of the exoskeleton does not exceed the movement limit of the human joint, avoid accidental injuries to the human body caused by the failure of the exoskeleton, and improve the safety of the exoskeleton. The normal movement range of the human knee joint is between 0° and 110°. Therefore, the limiting protrusions on the thigh bar 2 strictly control the flexion and extension angles of the exoskeleton within this range, so as to avoid the movement range of the exoskeleton exceeding the physiological limit and bringing potential hazards to the human body.

[0032] Referring to Figure 1 and Figure 2, a plurality of fixing plates 14 are detachably arranged on the thigh rod 2 and the calf rod 3. In this embodiment, two fixing plates 14 are arranged on both the thigh rod 2 and the calf rod 3. A plurality of thigh rings 101 and calf rings 102 are respectively arranged on the thigh rod 2 and the calf rod 3. In this embodiment, two thigh rings 101 and two calf rings 102 are arranged. The thigh ring 101 is installed on the thigh rod 2 through the fixing plate 14, and the calf ring 102 is installed on the calf rod 3 through the fixing plate 14. A plurality of mounting holes 15 are evenly formed in the thigh rod 2 and the calf rod 3 along their respective lengths. The fixing plate 14 is detachably installed on the thigh rod 2 or the calf rod 3 by bolts cooperating with the mounting holes 15. By installing the fixing plate 14 at different positions, it can be suitable for users with different leg lengths; both the thigh ring 101 and the calf ring 102 include a coil 1011 and a strap 1012. The coil 1011 is made of polytetrafluoroethylene and is fixed to the fixing plate 14 by bolts. The strap 1012 is wrapped outside the coil 1011. A through hole is formed in the fixing plate 14. When the strap 1012 wraps the installation part of the coil 1011 and the fixing plate 14, it is realized by passing through the through hole. A magic tape is arranged on the strap 1012, and the fixing of the strap 1012 is realized through the magic tape. The size of the circle formed by the coil 1011 is adjusted by the strap 1012, so as to wrap the coil 1011 outside the thigh or calf; a layer of gasket 16 is fixedly arranged inside the coil 1011. The gasket 16 is made of textile material. Through the arrangement of the gasket 16, the wrapping of the coil 1011 can be more comfortable.

[0033] The implementation principle of the embodiment of this application is as follows: adjust the installation position of the fixing plate 14 according to the lengths of the user's thigh and calf, and then install the thigh rod 2 and the calf rod 3 at the patient's knee joint through the binding device 1, so that the knee joint is aligned with the gear joint 4. Subsequently, the power member 5 drives the connecting rod 6 to rotate. The connecting rod 6 drives the transmission rod 7 to rotate and drive the calf rod 3. The rotation of the user's calf relative to the thigh is driven by the meshing of the large gear part 41 and the small gear part 42, so as to assist the patient in flexing and extending the knee joint and help the patient carry out rehabilitation training and some simple movements.

[0034] It should be noted that the above embodiments are only used to illustrate this application and do not limit the technical solutions described in this application. Although this specification has described this application in detail with reference to the above embodiments, those of ordinary skill in the art should understand that those skilled in the technical field can still modify this application or make equivalent replacements. All technical solutions and their improvements that do not depart from the spirit and scope of this application shall be covered within the scope of the claims of this application.

Claims

1. A motion-matching knee exoskeleton robot, comprising a binding device (1), and the binding device (1) includes a thigh loop (101) and a calf loop (102), characterized in that: A thigh rod (2) is installed on the thigh loop (101), a calf rod (3) is installed on the calf loop (102), a gear joint (4) is arranged between the thigh rod (2) and the calf rod (3), the gear joint (4) includes a large gear portion (41) and a small gear portion (42), the large gear portion (41) is installed on one side of the thigh rod (2) facing the calf rod (3), the small gear portion (42) is installed on one side of the calf rod (3) facing the thigh rod (2), the small gear portion (42) and the large gear portion (41) are meshed with each other, a power member (5) is installed on the thigh rod (2), a connecting rod (6) is installed on the power member (5), the power member (5) drives the connecting rod (6) to rotate, a transmission rod (7) is hinged on the connecting rod (6), one end of the transmission rod (7) is hinged to the connecting rod (6), and the other end is hinged to the calf rod (3).

2. The kinematic matching knee exoskeleton robot according to claim 1, characterized in that: A gear link (8) is arranged between the large gear portion (41) and the small gear portion (42), and the large gear portion (41) and the small gear portion (42) are respectively rotatably arranged at both ends of the gear link (8).

3. The kinematic matching knee exoskeleton robot according to claim 1, characterized in that: An installation platform (11) is installed on the thigh rod (2), and the motor is installed on the thigh rod (2) through the installation platform (11).

4. The kinematic matching knee exoskeleton robot according to claim 3, wherein: A limiting ring (12) is arranged on the installation platform (11), a limiting port (13) is opened on the limiting ring (12), and the connecting rod (6) is rotatably arranged in the limiting port (13).

5. A motion-matching knee exoskeleton robot according to claim 1, characterized in that: A plurality of fixing plates (14) are detachably arranged on the thigh rod (2) and the calf rod (3), a plurality of thigh loops (101) and calf loops (102) are respectively arranged on the thigh rod (2) and the calf rod (3), and the thigh loop (101) is installed on the thigh rod (2) through the fixing plate (14), and the calf loop (102) is installed on the calf rod (3) through the fixing plate (14).

6. The motion-matching knee exoskeleton robot according to claim 5, characterized in that: A plurality of installation holes (15) are uniformly opened along the length direction of the thigh rod (2) and the calf rod (3), and the fixing plate (14) is detachably installed on the thigh rod (2) or the calf rod (3) by bolts cooperating with the installation holes (15).

7. The kinematic matching knee exoskeleton robot according to claim 6, characterized in that: Both the thigh loop (101) and the calf loop (102) include a coil material (1011) and a binding band (1012), the coil material (1011) is fixedly installed on the fixing plate (14), and the binding band (1012) is wrapped outside the coil material (1011).

8. The kinematic matching knee exoskeleton robot according to claim 7, characterized in that: A layer of gasket (16) is fixedly arranged inside the coil material (1011).

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