A rope-driven powered exoskeleton device

Abstract

This invention relates to the field of rehabilitation and assistive robotics, and discloses a rope-driven assisted flexible exoskeleton device, comprising: a drive unit disposed at the torso position, fixed to the waist by a waist belt and fixed to the shoulder by shoulder straps; a lower limb fixation assembly including a knee brace body fixed around the knee joint by nylon straps; and at least three independent flexible transmission channels. This rope-driven assisted exoskeleton device, by centrally arranging the drive unit at the lower back and using three independent flexible transmission channels to distribute the driving force to the front of the thigh, the back of the thigh, and the back of the calf, achieves auxiliary torque output to the hip and ankle joints. Compared to motor-driven rigid exoskeletons, the drive unit of this invention is not located at the joint position, significantly reducing the mass and inertia of the lower limb end, and improving the wearer's movement compliance and comfort.

Description

Technical Field

[0001] This invention relates to the field of rehabilitation and assistive robot technology, specifically to a rope-driven assistive exoskeleton device. Background Technology

[0002] In the field of assistive walking, various lower limb exoskeleton devices have been proposed and applied in rehabilitation training, industrial assistance, and enhanced walking assistance. One common technical approach in the existing technology is the motor-driven lower limb exoskeleton structure. This type of device typically includes a lumbar fixation structure, a thigh or lower limb support structure, a motor drive unit located at the joints of the body, and rigid connectors or metal brackets connecting the various structural components.

[0003] Existing direct-drive exoskeletons generally employ a rigid frame structure, primarily constructed from metallic materials (such as aluminum alloys or steel components). Motors are typically positioned at the corresponding hip or knee joints on the human body, directly driving the exoskeleton joints to rotate via a reduction gear, thus providing power assistance. During operation, the control system, based on a preset gait model or sensor signals, drives the joint motors to output torque, causing the exoskeleton joints to rotate around their mechanical axes. This driving torque is then transmitted to the corresponding joints on the human body via fixed straps or a shell structure.

[0004] However, the rigid structure solution based on direct-drive motor still has room for improvement in practical applications, for example: (1) Due to the use of a large number of metal structural parts and high-power motor components, the overall device is heavy and bulky, which is not conducive to daily carrying and storage. (2) Rigid structures have limited adaptability to the human body’s degrees of freedom of movement. When there is a spatial offset between the actual rotation axis of the human joint and the mechanical rotation axis of the exoskeleton, additional loads or shear forces may be generated. (3) When gait recognition or control synchronization is insufficient, the direct drive motor may produce a certain degree of resistance or reverse damping effect on the natural movement of the human body, thereby affecting the coordination of human-computer interaction. (4) The cost of structural components and power units is relatively high, which is not conducive to lightweighting and widespread application; (5) Due to the rigid frame structure, the device is difficult to fold or compress for storage, and takes up a lot of space when traveling or not in use, making it less convenient to carry.

[0005] Therefore, while ensuring the assistive effect, how to reduce structural weight, improve human-machine motion matching, and enhance wearing comfort remain technical directions that need further optimization in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a rope-driven assisted exoskeleton device to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a rope-driven assisted flexible exoskeleton device, comprising: The drive unit is located on the human torso, fixed to the waist by a belt, and fixed to the shoulder by a shoulder strap; Lower limb fixation components, including a knee brace body secured around the knee joint by nylon straps; And at least three independent flexible transmission channels; The drive unit includes at least one drive mechanism, the output end of which is connected to the flexible transmission channel, for converting the output torque of the drive mechanism into tension in the flexible transmission channel. The at least three flexible transmission channels are arranged along different paths and are respectively connected to the front thigh fixation seat located on the front of the human thigh, the back thigh fixation seat located on the back of the human thigh, and the lower leg quick-release fixation seat located on the back of the human lower leg, so that when the flexible transmission channels are tensioned, they will generate forces at the three force-bearing positions respectively, thereby generating auxiliary torque on at least two joints during human movement.

[0008] Preferably, the driving unit further includes: Fixed back panel; The battery, drive control board, left drive module (16) and right drive module (17) are mounted on the fixed back plate. The left and right drive modules are mirror structures. Each drive module includes a motor base, and a lower leg side motor, a thigh back motor, and a thigh front motor mounted on the motor base. Each motor output shaft is coaxially fixed with a winch, which is used to convert the motor torque into the axial tension of the corresponding drive rope.

[0009] Preferably, the flexible transmission channel includes a Bowden rope system, which comprises: a spring tube holder, a spring tube, a Teflon Bowden tube, and a quick-release magnetic buckle connecting the drive rope and the corresponding holder; wherein the front path uses a metal spring tube and the rear path uses a Teflon Bowden tube.

[0010] Preferably, the quick-release magnetic buckle cooperates with the lower leg quick-release fixing seat to achieve rapid separation of the drive unit and the lower limb fixing component.

[0011] Preferably, the three flexible transmission channels are specifically: The front thigh drive cable is connected to the front thigh fixation seat; The posterior thigh drive cable is connected to the posterior thigh fixation seat; And the calf drive rope that connects to the calf fixation seat or the pull ring at the back of the shoe.

[0012] Preferably, the drive unit includes a control module, which generates gait phase information based on the attitude data collected by the IMU, fits the attitude data based on an adaptive oscillator model, determines the output timing of each motor through the oscillator phase, and thus controls the force application timing of the three flexible transmission channels. The expression for the oscillator is: , where A is the amplitude, ω is the angular frequency, and φ is the phase.

[0013] Preferably, the drive mechanism is any of the following alternative forms: a single motor combined with a shunt mechanism, a differential mechanism, or a multi-output shaft structure; or a combination structure of a motor and an elastic energy storage element.

[0014] Preferably, the flexible transmission channel is any one of the following flexible components: rope, steel cable, fiber belt or composite strip component; the guide structure in the Bowden rope system is any one of the following: composite material guide sleeve, low friction bushing structure or segmented guide structure; the fixing seat is any one of the following structures: flexible force distribution pad, fabric reinforcement area or embedded force module.

[0015] A power assist control method for the aforementioned device includes the following steps: Step 1: Collect lower limb posture angle data; Step 2: Construct a periodic oscillation model to fit the gait period; Step 3: Calculate the current gait phase; Step 4: Control the output tension of the flexible transmission channels connected to the front of the thigh, the back of the thigh, and the back of the calf according to the gait phase.

[0016] Compared with the prior art, the present invention provides a rope-driven assisted exoskeleton device, which has the following beneficial effects: 1. This rope-driven assisted exoskeleton device, by centrally arranging the drive unit in the lower back and employing three independent flexible transmission channels to distribute the driving force to the front of the thigh, the back of the thigh, and the back of the calf, achieves auxiliary torque output to the hip and ankle joints. Compared to motor-driven rigid exoskeletons, the drive unit of this invention is not located at the joint positions of the human body, significantly reducing the mass and inertia of the lower limbs and improving the wearer's movement compliance and comfort.

[0017] 2. This rope-driven assisted exoskeleton device uses a flexible transmission channel (such as the Bowden rope system) instead of a traditional rigid linkage. The driving force is transmitted through a flexible path, which can generate displacement compensation during human movement. This effectively avoids the additional load or shear force caused by the misalignment of the exoskeleton's mechanical rotation axis and the human joint axis, thus improving the human-machine kinematic matching and wearing safety.

[0018] 3. This rope-driven assisted exoskeleton device achieves multi-joint coordinated assistance through a three-channel distributed rope drive structure. Furthermore, by abandoning the traditional bulky, high-cost joint direct-drive motors and rigid frames, the overall structure is lighter and more flexible, facilitating folding and storage and improving portability.

[0019] 4. This rope-driven assisted exoskeleton device achieves quick separation of the power unit and the wearable part by setting a quick-release magnetic buckle between the drive unit and the lower limb fixation component, which facilitates quick putting on and taking off by the user and improves the ease of use of the product. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort: Figure 1 This is a schematic diagram of the driving unit of the present invention; Figure 2 This is a schematic diagram of the left and right drive modules of the present invention; Figure 3 This is a schematic diagram of the Bowden rope system of the present invention; Figure 4 This is a slanted view of the Bowden rope system of the present invention.

[0021] In the diagram: 1. Drive unit; 2. Waist belt; 3. Bourdon tube retainer; 4. Bourdon tube; 5. Teflon Bouden tube; 6. Quick-release magnetic buckle; 7. Rear thigh drive rope; 8. Rear calf drive rope; 9. Front thigh drive rope; 10. Rear thigh retainer; 11. Front thigh retainer; 12. Nylon strap; 13. Lower calf quick-release retainer; 14. Knee brace body; 15. IMU (Inertial Measurement Unit); 16. Left drive module; 17. Right drive module; 18. Shoulder strap; 19. Backplate; 20. Drive control board; 21. Battery; 22. Winch; 23. Lower calf motor; 24. Rear thigh motor; 25. Front thigh motor; 26. Motor mount. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] This invention provides a technical solution: Example 1

[0024] Please see Figures 1 to 4 This embodiment provides a rope-driven assisted exoskeleton device, the core of which is to replace the traditional rigid linkage structure with a flexible transmission method to achieve assistance to the human lower limbs.

[0025] The device mainly includes: a drive unit 1, a lower limb fixation component, and three independent flexible transmission channels.

[0026] The drive unit 1 is configured to be positioned on the human torso. Specifically, it is secured to the user's waist by a waist belt 2 and further secured to the shoulders by shoulder straps 18 to distribute the reaction force generated during drive. The core components of the drive unit 1 include a fixed back plate 19, and a battery 21, a drive control board 20, and left and right drive modules mounted on the fixed back plate. The left and right drive modules have a mirror-symmetrical structure to accommodate both lower limbs of the human body. Taking one side as an example, the side drive module includes a motor mount 26, and a lower leg motor 23, a posterior thigh motor 24, and a front thigh motor 25 mounted on the motor mount. A winch 22 is coaxially fixed to the output shaft of each motor.

[0027] The lower limb fixation assembly includes a knee brace body 14, which is secured to the user's knee joint by nylon straps 12. The knee brace body 14 serves as the main support and load-bearing base for the lower limb.

[0028] The three flexible transmission channels are specifically a Bowden rope system, which includes: a spring tube fixing seat 3, a spring tube 4, a Teflon Bowden tube 5, a quick-release magnetic buckle 6, and three independent drive ropes: a front thigh drive rope 9, a back thigh drive rope 7, and a back calf drive rope 8.

[0029] One end of each drive rope is fixed and wound around the corresponding winch 22 in the drive unit 1. Specifically, the front thigh drive rope 9 is driven by the winch of the front thigh motor 25, the back thigh drive rope 7 is driven by the winch of the back thigh motor 24, and the back calf drive rope 8 is driven by the winch of the calf motor 23. The other end of each drive rope is connected to a fixing seat located at different parts of the lower limbs via quick-release magnetic buckles 6: the front thigh drive rope 9 is connected to the front thigh fixing seat 11, which is used to fix it to the front of the thigh; the back thigh drive rope 7 is connected to the back thigh fixing seat 10, which is used to fix it to the back of the thigh; and the back calf drive rope 8 is connected to the calf quick-release fixing seat 13, which can be fixed to the back of the calf or connected to the pull ring at the heel of the shoe.

[0030] Regarding the path guidance of the drive ropes, in order to balance bending flexibility and low frictional resistance, this embodiment uses different guide tube materials for different paths. Specifically, for the front path with a larger bending angle (the path of the drive rope 9 on the front of the thigh), a metal spring tube 4 is used as its guide sleeve to provide better structural support and compressive strength. For the rear path (the paths of the drive rope 7 on the back of the thigh and the drive rope 8 on the back of the calf), a Teflon Bouden tube 5 with a lower coefficient of friction is used as the guide sleeve to reduce transmission loss.

[0031] Furthermore, to enable quick donning and doffing of the device, this embodiment incorporates a quick-detachable connection structure between the drive unit 1 and the lower limb fixation assembly. Specifically, the quick-release magnetic buckles 6 at the ends of each drive rope are connected to the corresponding quick-release lower leg fixation seat 13 or thigh fixation seat using a combination of magnetic attraction and mechanical engagement, allowing for quick switching of the power transmission path through simple insertion and removal.

[0032] The working principle of this embodiment is briefly described as follows: When the drive control board 20 issues a command, the corresponding motor starts, and its output shaft drives the coaxial winch 22 to rotate. The rotation of the winch 22 winds the drive rope wound around it inward, thereby converting the motor's output torque into axial tension on the drive rope. This tension is redirected and transmitted to the distal fixed seat through a guide path composed of a Bourdon tube 4 or a Teflon Bouden tube 5. The tension acting on the front of the thigh, the back of the thigh, and the back of the calf together form an auxiliary torque, acting on the hip and ankle joints, thus providing assistance during the user's walking. Because the driving force is transmitted through a flexible rope, and the weight of the drive unit is concentrated in the lower back, the burden on the lower limbs and the moment of inertia are effectively reduced.

[0033] Example 2

[0034] Based on Embodiment 1, this embodiment further introduces an attitude detection unit and a corresponding control module to achieve more intelligent and coordinated assist control.

[0035] In this embodiment, an IMU (Inertial Measurement Unit) 15 is fixed to the outside of the knee brace body 14. This IMU 15 acts as an attitude detection unit, used to collect real-time motion attitude data (such as angles and angular velocities) of the lower leg or thigh. This data is transmitted via wired or wireless means to a control module located within the drive unit 1 (this control module can be integrated onto the drive control board 20).

[0036] The control module has a built-in gait recognition algorithm. In this embodiment, the algorithm is based on an adaptive oscillator model and can perform real-time fitting of the continuous attitude angle signal θ(t) acquired by the IMU15. Its mathematical expression is: Where A is the real-time amplitude, ω is the angular frequency, and φ is the current gait phase. By calculating the gait phase φ, the control module can accurately determine the current gait cycle stage of the user (e.g., support phase, swing phase, etc.).

[0037] Based on the determined gait phase, the control module sends different control commands to the motors 25 on the front of the thigh, 24 on the back of the thigh, and 23 on the lower leg, according to a preset force application sequence. For example, during the push-off phase, the motors 24 on the back of the thigh and 23 on the lower leg primarily output high torque to simulate the exertion of human muscles; during the leg lift and swing phase, the motor 25 on the front of the thigh primarily outputs appropriate pulling force to assist in leg lift. This achieves the effect of "on-demand assistance" based on the natural rhythm of human movement, further enhancing the smoothness and naturalness of human-machine collaboration.

[0038] Alternative implementation methods The two embodiments described above are merely preferred embodiments of the present invention. It should be understood that, based on the core concept of the "three-channel distributed flexible tension transmission" of the present invention, those skilled in the art can foresee various equivalent alternatives or variations, all of which fall within the protection scope of the present invention.

[0039] For example: 1. Alternative Drive Mechanisms: Although the embodiment uses three independent motors to drive the three channels respectively, the drive mechanism can also be a single motor combined with a shunt mechanism, a differential mechanism, or a multi-output shaft structure to achieve independent or semi-independent drive of the three flexible transmission channels. Alternatively, the drive mechanism can also adopt a combination structure of a motor and an elastic energy storage element (such as a spring), using the elastic element to store and release energy to assist the motor output.

[0040] 2. Alternatives to Flexible Transmission Structures: The drive rope is not limited to round ropes; it can also be any flexible component capable of transmitting tension, such as steel cables, fiber tapes, or composite strip components. In Bowden rope systems, guide tubes, in addition to metal spring tubes and Teflon tubes, can also be composite material guide sleeves, low-friction bushing structures, or segmented guide structures.

[0041] 3. Replacement of force-bearing structures: The front thigh fixation seat 11, the back thigh fixation seat 10 and the calf quick-release fixation seat 13 are not necessarily rigid mechanical parts, but can also be flexible force-bearing distribution pads sewn or embedded in clothing or straps, locally reinforced fabric areas or small embedded force-bearing modules.

[0042] 4. Alternative layout of drive unit: In addition to being centrally located in the waist and back, drive unit 1 can also be distributed on both sides of the waist, both sides of the back, or other trunk positions that do not affect the freedom of the lower limbs, as needed.

[0043] In summary, any exoskeleton device that uses flexible rope drive and a three-channel distributed force transmission method based on the structural principles of this invention to provide multi-joint assistance to the lower limbs is considered to be within the scope of protection claimed by this invention.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A rope-driven assisted flexible exoskeleton device, characterized in that, include: The drive unit (1) is located on the human torso, fixed to the waist by a waist belt (2), and fixed to the shoulder by a shoulder strap (18); The lower limb fixation assembly includes a knee brace body (14) that is fixed around the knee joint by nylon straps (12); And at least three independent flexible transmission channels; The drive unit (1) includes at least one drive mechanism, the output end of which is connected to the flexible transmission channel to convert the output torque of the drive mechanism into tension in the flexible transmission channel; The at least three flexible transmission channels are arranged along different paths and are respectively connected to the front thigh fixation seat (11) located on the front of the human thigh, the back thigh fixation seat (10) located on the back of the human thigh, and the lower leg quick-release fixation seat (13) located on the back of the human lower leg, so that when the flexible transmission channels are tensioned, they will generate forces at the above three force-bearing positions, thereby generating auxiliary torque on at least two joints during human movement.

2. The rope-driven assisted exoskeleton device according to claim 1, characterized in that: The drive unit (1) further includes: Fixed back panel (19); The battery (21), drive control board (20), left drive module (16) and right drive module (17) are installed on the fixed back plate. The left and right drive modules are mirror structures. Each drive module includes a motor base (26), and a lower leg side motor (23), a thigh back side motor (24), and a thigh front side motor (25) mounted on the motor base. Each motor output shaft is coaxially fixed with a winch (22) to convert the motor torque into the axial tension of the corresponding drive rope.

3. The rope-driven assisted exoskeleton device according to claim 1, characterized in that: The flexible transmission channel includes a Bowden rope system, which includes: a spring tube fixing seat (3), a spring tube (4), a Teflon Bowden tube (5), and a quick-release magnetic buckle (6) connecting the drive rope and the corresponding fixing seat; wherein, the front path uses a metal spring tube (4), and the rear path uses a Teflon Bowden tube (5).

4. The rope-driven assisted exoskeleton device according to claim 3, characterized in that: The quick-release magnetic buckle (6) cooperates with the lower leg quick-release fixing seat (13) to realize the quick separation of the drive unit (1) and the lower limb fixing component.

5. The rope-driven assisted exoskeleton device according to claim 1, characterized in that: The three flexible transmission channels are specifically as follows: The front thigh drive rope (9) is connected to the front thigh fixation seat (11). The posterior thigh drive rope (7) is connected to the posterior thigh fixation seat (10). And the calf drive rope (8) connected to the calf rear fixing seat or the shoe rear pull ring.

6. The rope-driven assisted exoskeleton device according to claim 1, characterized in that: It also includes an attitude detection unit, which is an IMU (inertial measurement unit) (15) fixed to the outside of the knee brace body (14) for collecting human motion attitude data.

7. A rope-driven assisted exoskeleton device according to claim 6, characterized in that: The drive unit (1) includes a control module. The control module generates gait phase information based on the attitude data collected by the IMU, and fits the attitude data based on the adaptive oscillator model. The output timing of each motor is determined by the oscillator phase, thereby controlling the power generation timing of the three flexible transmission channels. The expression for the oscillator is: , where A is the amplitude, ω is the angular frequency, and φ is the phase.

8. The rope-driven assisted exoskeleton device according to claim 1, characterized in that: The drive mechanism can be any of the following alternative forms: a single motor combined with a shunt mechanism, a differential mechanism, or a multi-output shaft structure; or a combination structure of a motor and an elastic energy storage element.

9. The rope-driven assisted exoskeleton device according to claim 1, characterized in that: The flexible transmission channel is any of the following flexible components: rope, steel cable, fiber belt or composite strip component; the guide structure in the Bowden rope system is any of the following: composite material guide sleeve, low friction bushing structure or segmented guide structure; the fixing seat is any of the following structures: flexible force distribution pad, fabric reinforcement area or embedded force module.

10. A power assist control method for the device according to any one of claims 1 to 9, characterized in that, Includes the following steps: Step 1: Collect lower limb posture angle data; Step 2: Construct a periodic oscillation model to fit the gait period; Step 3: Calculate the current gait phase; Step 4: Control the output tension of the flexible transmission channels connected to the front of the thigh, the back of the thigh, and the back of the calf according to the gait phase.

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