A flexible rope-driven lower limb exoskeleton robot based on a variable stiffness actuator

Abstract

The present invention relates to a flexible, cable-driven lower limb exoskeleton robot based on a variable stiffness actuator, comprising a waist exoskeleton, the waist exoskeleton including a backrest and a waist adjustment assembly for adjusting the waist circumference of the exoskeleton robot; a thigh exoskeleton including an upper and lower adjustable thigh connecting rod; a calf exoskeleton including an upper and lower adjustable calf telescopic rod; an ankle exoskeleton mounted on the calf telescopic rod; a foot exoskeleton mounted on the ankle exoskeleton; and a control box in which a variable stiffness actuator is mounted. In the present invention, a knee joint actuator is mounted on the thigh of the exoskeleton, shifting the weight of the joint upward. Force and torque are transmitted between the actuator and the cable reel via a flexible Bowden cable, which can significantly reduce the mass and rotational inertia of the knee joint, thereby reducing the additional energy loss caused by joint misalignment and improving the wearability and human-machine coordination of the exoskeleton knee joint.

Description

Technical Field

[0001] The present invention relates to a flexible rope-driven lower limb exoskeleton robot, in particular to a flexible rope-driven lower limb exoskeleton robot based on a variable stiffness driver. Background Art

[0002] As a wearable human-machine interaction system, the lower-limb exoskeleton robot integrates multiple technologies, including anatomical structures, motor control, and sensors, to provide the wearer with additional power, achieving a power-saving effect. This power-saving effect can only be achieved in a favorable human-machine interaction environment; otherwise, the exoskeleton becomes an additional burden. Specifically, the exoskeleton structure and motor control scheme should be designed to closely match the human body.

[0003] However, compared with most existing domestic and foreign studies, the following problems were found: the drivers are directly installed at the joints, which has low safety and increases the moment of inertia at the joints, reducing the wearability of the exoskeleton; rigid joints or joints with immutable rigidity are often used, which lack flexibility; a few variable stiffness structures also have complex structures, and the stiffness adjustment range is difficult to change due to structural limitations; the exoskeleton does not have a size adjustment structure or lacks a fast and continuous size adjustment structure, making it difficult to adapt to rapid wear by different people. Summary of the Invention

[0004] The present invention aims to address the above-mentioned deficiencies in the existing technology and develop a flexible rope-driven lower limb exoskeleton robot based on a variable stiffness driver. The core of the present invention is to develop a lower limb exoskeleton robot structure with a good human-computer interaction environment, the ability of the knee joint to actively adjust stiffness, motion flexibility and strong bionics.

[0005] The beneficial effects of the above scheme are:

[0006] In this invention, the knee joint actuator is mounted on the exoskeleton's thigh, shifting the joint's weight upward. Flexible Bowden cables transmit force and torque between the actuator and the cable reel, significantly reducing the mass and rotational inertia of the knee joint. This helps mitigate the additional energy loss caused by joint misalignment, improving the exoskeleton's wearability and human-machine interaction. Furthermore, a variable-stiffness drive scheme is employed in the knee joint to ensure that the exoskeleton's joint stiffness changes with the body's stiffness during walking, enhancing the exoskeleton's human-machine interaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 A schematic structural diagram of a robot provided in an embodiment of the present invention;

[0008] Figure 2 A schematic structural diagram of a waist exoskeleton provided in an embodiment of the present invention;

[0009] Figure 3A schematic diagram of a partially exploded structure of a waist exoskeleton in an embodiment of the present invention;

[0010] Figure 4 A schematic structural diagram of a thigh exoskeleton provided in an embodiment of the present invention;

[0011] Figure 5 A schematic structural diagram of a calf exoskeleton provided in an embodiment of the present invention;

[0012] Figure 6 Schematic diagram of the installation of the ankle exoskeleton and the foot exoskeleton in an embodiment of the present invention.

[0013] In the accompanying drawings: 10, waist exoskeleton; 11, back pillow; 12, waist and back slider; 13, hip joint fixing part; 14, waist and back connecting part; 15, hip joint slider; 16, waist and hip rotation pair; 17, hip joint connecting part; 18, waist and back outer shell; 19, waist and back inner shell; 110, waist and back cam handle; 111, hip joint cam handle; 20, thigh exoskeleton; 21, thigh connecting rod; 22, driver mounting frame; 23, hip joint driver; 24, hip joint output rod; 25, thigh guide rail; 26, upper thigh inner shell; 27, Upper thigh outer shell; 28. Lower thigh inner shell; 29. ​​Lower thigh outer shell; 210. Upper thigh nesting shell; 211. Thigh connecting rod cam handle; 30. Calf exoskeleton; 31. Calf telescopic rod; 32. Calf connecting rod; 33. Bearing outer baffle; 34. Bearing inner baffle; 35. Routing bracket; 36. Cable drum; 37. Step shaft; 38. Calf inner shell; 39. Calf outer shell; 310. Telescopic rod cam handle; 40. Ankle exoskeleton; 50. Foot exoskeleton; 51. Joint connecting rod; 52. Foot pedal; 60. Control box. DETAILED DESCRIPTION

[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0015] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other.

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0017] like Figures 1 to 6As shown, the robot provided in the embodiment of the present invention includes a waist exoskeleton 10, which includes a back pillow 11 and a waist adjustment component for adjusting the waist of the exoskeleton robot; a thigh exoskeleton 20, which includes an upper and lower adjustable thigh connecting rod 21, and the thigh exoskeleton 20 is installed on the waist adjustment component; a calf exoskeleton 30, which includes a calf telescopic rod 31; a calf connecting rod 32, which is equipped with a bearing outer baffle 33, a bearing inner baffle 34 and a wire drum 36, and the calf exoskeleton 30 includes a lower leg extending rod 31; a lower leg connecting rod 32, and the lower leg connecting rod 32 is equipped with a bearing outer baffle 33, a bearing inner baffle 34 and a wire drum 36, and the lower leg extending rod 31 includes a lower leg extending rod 31; a lower leg connecting rod 32, and the lower leg connecting rod 32 includes ... the lower leg connecting rod 32 includes a lower leg extending rod 31, and the lower leg extending rod 32 includes a lower leg extending rod 31; the lower leg connecting rod 32 includes a lower leg extending rod 31, and the lower leg extending rod 32 includes a lower leg extending rod 31; the lower leg connecting rod 32 includes a lower leg extending rod 31, and the lower leg extending rod 32 includes a lower leg extending rod 31, and the lower leg extending rod 32 includes a lower leg extending rod 31, and the lower leg extending rod The connecting rod 32 is installed on the thigh connecting rod 21 through the inner bearing baffle 34, and the wiring bracket 35 is installed on the outer bearing baffle 33. The calf telescopic rod 31 is adjustable up and down and embedded in the calf connecting rod 32; and the wire drum 36, the wire drum 36 is installed on the calf connecting rod 32 through the stepped shaft 37; the ankle exoskeleton 40, the ankle exoskeleton 40 is installed on the calf telescopic rod 31; the foot exoskeleton 50, the foot exoskeleton 50 is installed on the ankle exoskeleton 40; and the control box 60, the control box 60 is installed with a variable stiffness driver.

[0018] The detailed structure of the variable stiffness actuator in this invention is disclosed in patent application number CN202211140968.5, entitled "An Antagonistic Variable Stiffness Structure and Antagonistic Variable Stiffness Flexible Actuator." The principle behind this actuator is to achieve varying joint stiffness by varying the fulcrum compression spring, and therefore will not be further described here. To reduce the mass and moment of inertia of the calf exoskeleton 30, the variable stiffness actuator is installed in the control box 60 on the back of the waist exoskeleton 10.

[0019] In the present invention, one end of one Bowden cable on the cable drum 36 passes through a reserved hole in the inner track of the cable drum 36, winds counterclockwise around the cable drum 36 half a turn, then passes through the left side of the cable drum 36. It then passes through the preload structure of the variable stiffness actuator and the cable routing bracket 35, and is connected to the left side of the cable drum 36 to control the extension movement of the calf exoskeleton 30. Another end of the Bowden cable on the cable drum 36 passes through a reserved hole in the outer track of the cable drum 36, winds clockwise around the cable drum 36 half a turn, then passes through the right side of the cable drum 36, and then passes through the preload structure of the variable stiffness actuator and the cable routing bracket 35, and is connected to the right side of the cable drum 36 to control the flexion movement of the calf exoskeleton 30. In the present invention, the cable winding methods on the left and right calf exoskeletons 30 are mirror images of each other. The rope-driven arrangement structure moves the joint motor upward, reducing the mass of the leg and improving the wearability of the exoskeleton. At the same time, the knee joint uses a smaller diameter wire drum instead of the joint motor, which greatly reduces the joint rotational inertia. This can avoid the additional energy loss caused by joint alignment problems to a certain extent, and improve the human-machine coordination at the exoskeleton knee joint.

[0020] Taking into account the different heights of different wearers and their different wearing requirements when wearing and using the robot, the thigh exoskeleton 20 and calf exoskeleton 30 are optimized in design. When in use, the wearer adjusts the thigh connecting rod 21 and the calf telescopic rod 31 in turn to adapt to the height, and then puts on the exoskeleton robot and uses it.

[0021] As a specific example, the waist adjustment assembly includes two waist and back sliders 12, which are adjustable left and right and embedded in the backrest portion 11; two hip joint fixing members 13, which are correspondingly mounted on the waist and back sliders 12 via waist and back connectors 14; and two hip joint sliders 15, which are adjustable front and back and embedded in the hip joint fixing members 13. The hip joint sliders 15 are mounted with hip joint connectors 17 via waist-hip rotation pairs 16, and the thigh exoskeleton 20 is mounted on the hip joint connectors 17. Under the above structure, when adjustment is needed, the waist and back sliders 12 can be adjusted left and right first to the appropriate position and then locked. The hip joint sliders 15 can then be adjusted front and back to the appropriate position and then locked to accommodate different wearer waist circumferences.

[0022] Furthermore, in order to improve safety and avoid contact between the wearer's body and the robot component, the above-mentioned waist adjustment component may also include an outer waist and back shell 18, which is fixed on the side wall of the hip joint fixing component 13 on the side relatively away from the wearer; and an inner waist and back shell 19, which is fixed on the side wall of the hip joint fixing component 13 on the side relatively close to the wearer. The inner waist and back shell 19 and the outer waist and back shell 18 surround and cover the periphery of the hip joint fixing component 13 to avoid entanglement of the wearer's clothes and the like with the corresponding structure.

[0023] As a specific example of adjusting and locking the corresponding structure, the waist adjustment component in the present invention may also include two waist and back cam handles 110, which are installed on the back pillow part 11; and two hip joint cam handles 111, which are installed on the hip joint fixing part 13; under the above structure, after adjusting the waist and back slider 12 to an appropriate position, the waist and back cam handles 110 can be used to lock the waist and back slider 12 on the back pillow part 11, and then the hip joint slider 15 can be adjusted to an appropriate position and then the hip joint cam handles 111 can be used to lock the hip joint slider 15.

[0024] As a specific example, the thigh exoskeleton 20 includes a driver mounting frame 22, on which a hip joint driver 23 is mounted; a hip joint output rod 24, which is mounted on the output end of the hip joint driver 23; and a thigh guide rail 25, which is mounted on the hip joint output rod 24 via a thigh rotation pair, and a thigh link 21 is adjustably mounted on the thigh guide rail 25. Under the above structure, when adjustment is required, the thigh link 21 can be adjusted up and down to the appropriate position and then locked to accommodate different thigh lengths of the wearer.

[0025] Furthermore, in order to improve safety and avoid contact between the wearer's body and the robot components, the above-mentioned thigh exoskeleton 20 may also include an upper inner thigh shell 26, which is installed on the side of the thigh guide 25 facing the wearer; an upper outer thigh shell 27, which is installed on the side of the thigh guide 25 facing away from the wearer, the upper outer thigh shell 27 is clamped on the upper inner thigh shell 26, and the upper outer thigh shell 27 and the upper inner thigh shell 26 are surrounded and covered on the periphery of the thigh guide 25; a lower inner thigh shell 28, which is installed on the side of the thigh connecting rod 21 facing the wearer; a lower outer thigh shell 29, which is installed on the side of the thigh connecting rod 21 facing away from the wearer, and the lower outer thigh shell 29 is clamped on the lower thigh The upper thigh nested shell 210 is fixedly mounted on the thigh connecting rod 21, and the upper thigh nested shell 210 is also embedded in the upper thigh outer shell 27. Under the above structure, the upper thigh inner shell 26 and the upper thigh outer shell 27 are used to cover the outer periphery of the thigh guide rail 25, and the lower thigh inner shell 28 and the lower thigh outer shell 29 are used to cover the outer periphery of the thigh connecting rod 21. When the thigh connecting rod 21 is adjusted up and down, the upper thigh nested shell 210 can move up and down synchronously with the thigh connecting rod 21 to avoid entanglement of the wearer's clothes and the corresponding structure.

[0026] As a specific example of adjusting and locking the corresponding structure, the thigh exoskeleton 20 of the present invention may also include a thigh link cam handle 211. Under the above structure, when the thigh link 21 is adjusted to an appropriate position, the thigh link cam handle 211 can be used to lock the thigh link.

[0027] In order to improve safety and avoid contact between the wearer's body and the robot components in the present invention, the calf exoskeleton 30 may also include an inner calf shell 38, which is installed on the side wall of the calf connecting rod 32 close to the wearer; and an outer calf shell 39, which is installed on the other side wall of the calf connecting rod 32 away from the wearer. The outer calf shell 39 is clamped on the inner calf shell 38, and the outer calf shell 39 and the inner calf shell 38 are surrounded and covered on the periphery of the calf connecting rod 32; under the above structure, when the calf telescopic rod 31 is adjusted up or down, the calf telescopic rod 31 can be extended from or retracted into the shell structure accordingly to avoid entanglement between the wearer's clothes and the structural parts.

[0028] The ankle exoskeleton 40 of the present invention is an ankle revolute pair having a passive single degree of freedom, which makes this part of the structure simple and can bear a large weight; the foot exoskeleton 50 includes a joint link 51 and a foot pedal 52, which is mounted on the ankle revolute pair through the joint link.

[0029] In the lower limb exoskeleton robot of the present application, the hip joint and knee joint are each provided with one active degree of freedom, the hip joint is provided with two passive degrees of freedom, and the ankle joint is provided with one passive degree of freedom, so as to improve the coordination of human walking movement while ensuring the stability of the structure.

[0030] The above are only preferred embodiments of the present invention and do not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A flexible rope-driven lower limb exoskeleton robot based on a variable stiffness actuator, characterized in that: include: A waist exoskeleton, comprising a backrest portion and a waist adjustment component for adjusting the waist circumference of the exoskeleton robot; A thigh exoskeleton, comprising upper and lower adjustable thigh links, and mounted on the waist adjustment assembly; A calf exoskeleton, comprising a calf telescopic rod; a calf connecting rod, wherein the calf connecting rod is mounted with an outer bearing baffle, an inner bearing baffle, and a cable drum; the calf connecting rod is mounted on the thigh connecting rod via the inner bearing baffle; a cable routing bracket is mounted on the outer bearing baffle; the calf telescopic rod is adjustable up and down on the calf connecting rod; and a cable drum, wherein the cable drum is mounted on the calf connecting rod via a stepped shaft; Ankle joint exoskeleton, the ankle joint exoskeleton is installed on the calf telescopic rod; a foot exoskeleton, the foot exoskeleton being mounted on the ankle exoskeleton; as well as A control box, wherein a variable stiffness driver is installed in the control box; Among them, one end of one of the Bowden cables on the cable drum passes through the reserved hole in the inner track of the cable drum, goes around the cable drum half a circle counterclockwise, and then passes through the left side of the cable drum, and then passes through the preloaded structure in the variable stiffness driver and the cable bracket in sequence, and then is connected to the left side of the cable drum to control the calf exoskeleton to perform extension movement; one end of the other Bowden cable on the cable drum passes through the reserved hole in the outer track of the cable drum, goes around the cable drum half a circle clockwise, and then passes through the right side of the cable drum, and then passes through the preloaded structure in the variable stiffness driver and the cable bracket in sequence, and then is connected to the right side of the cable drum to control the calf exoskeleton to perform flexion movement.

2. The flexible rope-driven lower limb exoskeleton robot according to claim 1, characterized in that: The waist adjustment component includes: Two waist and back sliders, the waist and back sliders are adjustable left and right and embedded on the back pillow; Two hip joint fixing members, each of which is correspondingly mounted on the waist and back slider via a waist and back connecting member; and Two hip joint sliders are adjustable frontally and rearwardly and embedded in the hip joint fixing member. A hip joint connector is mounted on the hip joint slider via a waist-hip rotation pair, and the thigh exoskeleton is mounted on the hip joint connector.

3. The flexible rope-driven lower limb exoskeleton robot according to claim 2, characterized in that: The waist adjustment component also includes: A waist and back outer shell fixed to the side wall of the hip joint fixing component on the side facing away from the wearer; and The inner shell of the waist and back is fixed on the side wall of the hip joint fixing component relatively close to the wearer. The inner shell of the waist and back and the outer shell of the waist and back surround and cover the periphery of the hip joint fixing component.

4. The flexible rope-driven lower limb exoskeleton robot according to claim 2 or 3, characterized in that: The waist adjustment component also includes: Two waist and back cam handles, used for correspondingly adjusting and locking the waist and back sliders, the waist and back cam handles being installed on the back pillow portion; and Two hip joint cam handles are used for correspondingly adjusting and locking the hip joint sliders, and the hip joint cam handles are installed on the hip joint fixing component.

5. The flexible rope-driven lower limb exoskeleton robot according to claim 1, characterized in that: The thigh exoskeleton comprises: a driver mounting frame, on which a hip joint driver is mounted; A hip joint output rod, the hip joint output rod being mounted on the output end of the hip joint driver; A thigh guide rail is mounted on the hip joint output rod through a thigh rotating pair, and the thigh connecting rod is mounted on the thigh guide rail in an upward and downward adjustable manner.

6. The flexible rope-driven lower limb exoskeleton robot according to claim 5, characterized in that: The thigh exoskeleton further comprises: an upper inner thigh shell mounted on the side of the thigh rail facing the wearer; An upper outer thigh shell is mounted on the side of the thigh rail facing away from the wearer, the upper outer thigh shell is snap-connected to the upper inner thigh shell, and the upper outer thigh shell and the upper inner thigh shell surround and cover the outer periphery of the thigh rail; a lower inner thigh shell mounted on the side of the thigh link facing the wearer; a lower thigh outer shell, mounted on the side of the thigh connecting rod facing away from the wearer, the lower thigh outer shell being snap-connected to the lower thigh inner shell, and the lower thigh outer shell and the lower thigh inner shell encircling and covering the outer periphery of the thigh connecting rod; and The upper thigh nesting shell is fixedly mounted on the thigh connecting rod, and the upper thigh nesting shell is also embedded in the upper thigh outer shell.

7. The flexible rope-driven lower limb exoskeleton robot according to claim 5 or 6, characterized in that: The thigh exoskeleton further comprises: The thigh connecting rod cam handle is used for adjusting and locking the thigh connecting rod, and the thigh connecting rod cam handle is installed on the thigh guide rail.

8. The flexible rope-driven lower limb exoskeleton robot according to claim 1, characterized in that: The calf exoskeleton further comprises: The inner calf shell is mounted on the side wall of the calf link close to the wearer; and The outer calf shell is installed on the side wall of the calf connecting rod away from the wearer. The outer calf shell is clamped on the inner calf shell, and the outer calf shell and the inner calf shell surround and cover the outer periphery of the calf connecting rod.

9. The flexible rope-driven lower limb exoskeleton robot according to claim 8, characterized in that: The calf exoskeleton also includes: The telescopic rod cam handle is used to adjust and lock the calf telescopic rod, and the telescopic rod cam handle is installed on the calf telescopic rod.

10. The flexible rope-driven lower limb exoskeleton robot according to claim 1, characterized in that: The ankle exoskeleton is an ankle revolute pair, and the foot exoskeleton includes a joint connecting rod and a foot pedal, wherein the foot pedal is mounted on the ankle revolute pair through the joint connecting rod.

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