Self-adaptive knee joint exoskeleton
By designing an adaptive knee exoskeleton, combined with a dual four-bar linkage and a drive motor, the kinematic compatibility problem of existing exoskeletons at the knee joint is solved, achieving lightweight and highly comfortable rehabilitation assistance.
Patent Information
- Application Number
- CN202510765583.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-10
- Publication Date
- 2026-01-16
AI Technical Summary
Existing lower limb exoskeletons have poor kinematic matching at the knee joint, leading to human-machine coordination errors, increasing the burden on the wearer, and being too heavy, which affects the wearer's comfort and rehabilitation effect.
It adopts an adaptive knee exoskeleton design, including a back assembly, a hip joint adjustment assembly, a telescopic adjustable thigh assembly, a knee joint mechanism, and a telescopic adjustable calf assembly. Combined with a dual four-bar linkage and a drive motor, it achieves a high degree of matching with the human knee joint and provides auxiliary power at the hip, knee, and ankle joints.
It improves wearer comfort and rehabilitation outcomes, reduces weight and trajectory errors, provides better kinematic fit and assistive power, and enhances patients' daily activity abilities.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of medical device technology, specifically to an exoskeleton mechanical structure for providing assistance to paralyzed patients in their daily activities. Background Technology
[0002] Robotic devices such as exoskeletons are used to help paralyzed patients complete daily tasks, assist in neurological rehabilitation, and simultaneously improve users' mobility. Lower limb exoskeletons are mobility devices installed on the lower limbs, providing at least some of the necessary activation energy for lower limb movement. Therefore, human operators can perform tasks that would otherwise be impossible for them alone. Typically, lower limb robotic exoskeletons provide power at major joints in both legs, such as the hip, knee, and ankle joints. Due to their broad potential to improve gait patterns during rehabilitation and their significant effects on walking assistance, lower limb exoskeletons are of great importance in improving quality of life, walking ability, cardiovascular endurance, and motor neuron status in terms of disability and human strength enhancement.
[0003] Most existing exoskeletons employ simple rotational (hinge) joints at the hip, knee, and ankle. Since the human knee joint has three degrees of freedom, this overly simplified design leads to a kinematic mismatch between the human knee and the exoskeleton joints, causing human-machine coordination errors. Secondly, many typical prostheses have uniaxial knee joints, causing the wearer to experience tremors at the hip joint and a pulling sensation at the ankle. Furthermore, uniaxial knee joints increase the burden on the leg, generating unnecessary forces and torques at the joint. Simultaneously, many lower limb exoskeletons use cams and followers or gear mechanisms to mimic the multi-center behavior of the biological knee joint; however, these systems increase the exoskeleton's weight. Although some studies have considered the design of multi-center knee joints, detailed design and optimization of their mechanisms remain insufficient. Summary of the Invention
[0004] This invention overcomes the shortcomings of existing technologies and provides an adaptive knee exoskeleton that effectively solves the problems of good kinematic matching, high wearer comfort, and light human burden in existing lower limb rehabilitation exoskeletons.
[0005] The present invention achieves its objective using the following technical solution: A structural design for an adaptive knee exoskeleton includes: a back assembly (Ⅰ), a hip joint adjustment assembly (Ⅱ), a telescopic adjustable thigh assembly (Ⅲ), a knee joint mechanism (IV), a telescopic adjustable lower leg assembly (V), and a foot assembly (VI).
[0006] Furthermore, the back support is secured to the power supply and driver unit by screws.
[0007] Furthermore, the hip joint fixing section is connected to the hip joint adjusting section by screws, allowing both to be adjusted in length and width; the hip joint adjusting section, servo motor, connector 1 and hip-thigh connecting section are connected by rivets, wherein the hip joint adjusting section and hip-thigh connecting section can rotate relative to each other through human movement; the hip-thigh connecting section, servo motor and connector 2 are connected by rivets.
[0008] Furthermore, the upper thigh and the hip joint-thigh connection segment are able to rotate relative to each other via connector 2; the upper thigh is connected to the lower thigh via screws, allowing both to be adjusted in length and width; the thigh support and the lower thigh are fixed together via screws.
[0009] Furthermore, the motor end cap is connected by embedding a servo motor; the transmission rod connects the motor end cap and the connecting ligament; the tracking active crank is placed between the lower half of the thigh and the upper half of the calf, and is connected by rivets, allowing the two to rotate relative to each other; the tracking driven crank is placed at both ends of the lower half of the thigh and the upper half of the calf, and is connected by rivets, allowing the two to rotate relative to each other.
[0010] Furthermore, the upper part of the lower leg is connected to the lower part of the lower leg by screws, allowing both to be adjusted for extension and retraction; the lower leg support and the upper part of the lower leg are fixed by screws.
[0011] Furthermore, the servo motor and the calf-foot connector are connected by connector 3; the helical spring is embedded in the calf-foot connector and fixed by screws; the foot plate and the calf-foot connector are connected by rivets, allowing them to rotate relative to each other; the retainer is fixed to the foot plate by screws. Beneficial effects
[0012] Compared with the prior art, the beneficial effects of this invention are reflected in: The invention describes the effects of the technical solution in words. It employs an adaptive knee exoskeleton design to assist paralyzed patients with daily activities. A dual four-bar linkage is used as the exoskeleton's knee joint to achieve a high degree of matching with human knee joint movement. Furthermore, the device has drive motors at the hip, knee, and ankle joints, providing auxiliary power during patient movement and rehabilitation, and helping the exoskeleton maintain balance. Compared to other exoskeletons, this invention is lighter, more compact, and has less trajectory error, improving wearer comfort and rehabilitation effectiveness. Attached Figure Description
[0013] Figure 1 This is a diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the back component structure; Figure 3This is a schematic diagram of the hip joint adjustment component. Figure 4 This is a schematic diagram of the retractable and adjustable thigh assembly structure; Figure 5 This is a schematic diagram of the knee joint mechanism; Figure 6 This is a schematic diagram of the retractable and adjustable lower leg assembly. Figure 7 This is a schematic diagram of the foot component structure; In the diagram: 1-Back support, 2-Power supply and driver, 3-Lumbar support, 4-Hip joint fixation section, 5-Hip joint adjustment section, 6-Servo motor, 7-Connector 1, 8-Hip joint-thigh connector, 9-Servo motor, 10-Connector 2, 11-Upper thigh, 12-Lower thigh, 13-Thigh support, 14-Motor end cap, 15-Servo motor, 16-Drive rod, 17-Connecting ligament, 18-Tracking active crank, 19-Tracking driven crank, 20-Upper lower leg, 21-Lower leg support, 22-Lower lower leg, 23-Servo motor, 24-Connector 3, 25-Lower leg-foot connector, 26-Coil spring, 27-Footplate, 28-Fixer. Detailed Implementation
[0014] The present invention will now be described in detail with reference to the accompanying drawings. like Figures 1 to 7 As shown, the structural design of an adaptive knee exoskeleton described in this invention includes a back assembly I, a hip joint adjustment assembly II, a telescopic adjustable thigh assembly III, a knee joint mechanism IV, a telescopic adjustable lower leg assembly V, and a foot assembly VI.
[0015] Specifically, the back support (1) of the back assembly I is fixed to the power supply and driver device (2) by screws.
[0016] Specifically, the lumbar support (3) of the hip joint adjustment component II is fixed to the hip joint fixing section (4) by screws; the hip joint fixing section (4) is connected to the hip joint adjustment section (5) by screws, allowing both to be adjusted in extension and retraction; the hip joint adjustment section (5), servo motor (6), connector 1 (7) and hip joint-thigh connection section (8) are connected by rivets, wherein the hip joint adjustment section (5) and hip joint-thigh connection section (8) can rotate relative to each other through human movement; the hip joint-thigh connection section (8), servo motor (9) and connector 2 (10) are connected by rivets.
[0017] Specifically, the upper thigh part (11) and the hip joint-thigh connection section (8) of the retractable and adjustable thigh assembly III are able to rotate relative to each other through the connector 2 (10); the upper thigh part (11) is connected to the lower thigh part (12) by screws, allowing both to be retracted and adjusted; the thigh support (13) and the lower thigh part (12) are fixed by screws.
[0018] Specifically, the motor end cap (14) of the knee joint mechanism IV is connected by embedding a servo motor (15); the transmission rod (16) connects the motor end cap (14) and the connecting ligament (17); the tracking active crank (18) is placed between the lower thigh (12) and the upper calf (20) and is connected by rivets, allowing the two to rotate relative to each other; the tracking driven crank (19) is placed at both ends of the lower thigh (12) and the upper calf (20) and is connected by rivets, allowing the two to rotate relative to each other.
[0019] Specifically, the upper part (20) of the retractable adjustable calf assembly V and the calf support (21) are fixed by screws; the upper part (20) of the calf is connected to the lower part (22) of the calf by screws, allowing both to be retracted and adjusted.
[0020] Specifically, the servo motor (23) of the foot component VI and the calf-foot connector (24) are connected by connector 3 (25); the coil spring (26) is embedded in the calf-foot connector (24) and fixed by screws; the foot plate (27) and the calf-foot connector (24) are connected by rivets, allowing them to rotate relative to each other; the retainer (28) is fixed to the foot plate (27) by screws.
[0021] The working process of this invention: When in use, the knee exoskeleton belt will fix the wearer in place. The thigh support (13) and calf support (21) allow for a certain amount of movement to compensate for the locked degree of freedom. The fixator (28) can firmly fix the wearer's shoes. That is, the exoskeleton will connect to the human body at the waist, thigh and calf segments and foot pedals to assist the patient in rehabilitation exercises.
[0022] The rotational motion of the servo motor (6) is transmitted to the hip-thigh connection section (8) through the hip joint adjustment section (5), thereby assisting the human hip joint in adduction and abduction movements. In addition, the hip joint adjustment section is provided with equidistant threaded holes, allowing for a 20cm size adjustment, which can be adjusted according to the size of the human hip joint, giving the patient a comfortable wearing experience.
[0023] The rotational motion of the servo motor (9) is transmitted to the upper thigh (11) and lower thigh (12) through the hip joint-thigh connection segment (8). This assists the human hip joint in making flexion and extension movements.
[0024] The upper part (11) of the thigh segment is connected to the lower part (12) of the thigh segment by screws. The upper part (20) of the calf segment is connected to the lower part (22) of the calf segment by screws. Both the thigh segment and the calf segment are provided with equidistant threaded holes. The thigh segment allows for 8cm size adjustment and the calf segment allows for 10cm size adjustment. The size can be adjusted according to the length of the human leg to accommodate patients of different heights and provide patients with a comfortable wearing experience.
[0025] The rotational motion of the servo motor (15) is transmitted to the transmission rod (16) through the motor end cap. The end of the transmission rod (16) is connected to the connecting ligament (17), so the rotational motion of the servo motor (15) can drive the connecting ligament (17) to rotate. The connecting ligament (17) connects the lower thigh (12) and the upper calf (20) surface. The tracking active crank (18) connects the lower thigh (12) and the upper calf (20), so the torque of the servo motor (15) can drive the tracking active crank (18) to move. The movement of the tracking active crank (18) is transmitted to the tracking driven crank (19) through the upper end of the upper calf (20). This assists the human knee joint in making bending and extension movements.
[0026] The rotational motion of the servo motor (23) is transmitted to the lower leg-foot connector (25) through the lower half of the lower leg (25). The lower leg-foot connector (25) is connected to the foot plate (27), so the rotational motion of the servo motor (23) can drive the foot plate (27) to move. This assists the human ankle joint in dorsiflexion and plantarflexion.
[0027] The lower leg-foot connector (25) is connected to the foot plate (26) via a coil spring (16), allowing the lower leg-foot connector (25) and the foot plate (26) to rotate relative to each other, thereby assisting the human ankle joint in inversion and eversion movements.
[0028] The above embodiments are merely illustrative examples of this patent and do not limit its scope of protection. Those skilled in the art can make partial changes to them, as long as they do not exceed the spirit and essence of this patent, they are all within the scope of protection of this patent.
Claims
1. A structural design for an adaptive knee exoskeleton, comprising: The back assembly (Ⅰ), hip joint adjustment assembly (Ⅱ), telescopic adjustable thigh assembly (Ⅲ), knee joint mechanism (IV), telescopic adjustable calf assembly (V) and foot assembly (VI) are characterized in that the back assembly (Ⅰ) is fixed to the hip joint adjustment assembly (Ⅱ) by screws, the hip joint-thigh connection section (7) and servo motor (8) of the hip joint adjustment assembly (Ⅱ) are rotatably connected to the telescopic adjustable thigh assembly (Ⅲ) by connector (9), the telescopic adjustable thigh assembly (Ⅲ) and the telescopic adjustable calf assembly (V) are movably connected by knee joint mechanism (IV), and the lower half (21) of the calf of the telescopic adjustable calf assembly (V) is connected to the calf-foot connector (25) of the foot assembly (VI).
2. The adaptive knee exoskeleton structure design according to claim 1, characterized in that, The back assembly (Ⅰ) includes a back support (1) and a power supply and driver unit (2). The back support (1) is fixed to the power supply and driver unit (2) by screws.
3. The adaptive knee exoskeleton structure design according to claim 1, characterized in that, The hip joint adjustment assembly (II) includes: a lumbar support (3), a hip joint fixation section (4), a hip joint adjustment section (5), a servo motor (6), a connector 1 (7), a hip joint-thigh connection section (8), a servo motor (9), and a connector 2 (10). The lumbar support (3) is fixed to the hip joint fixation section (4) by screws; the hip joint fixation section (4) is connected to the hip joint adjustment section (5) by screws, allowing both to be adjusted in a telescopic manner; the hip joint adjustment section (5), the servo motor (6), the connector 1 (7), and the hip joint-thigh connection section (8) are connected by rivets, wherein the hip joint adjustment section (5) and the hip joint-thigh connection section (8) can rotate relative to each other through human movement; the hip joint-thigh connection section (8), the servo motor (9), and the connector 2 (10) are connected by rivets.
4. The adaptive knee exoskeleton structure design according to claim 1, characterized in that, The retractable and adjustable thigh assembly (Ⅲ) includes: an upper thigh part (11), a lower thigh part (12), and a thigh support (13). The upper thigh part (11) and the hip joint-thigh connection section (8) can rotate relative to each other through a connector 2 (10); the upper thigh part (11) is connected to the lower thigh part (12) by screws, allowing both to be retracted and adjusted; the thigh support (13) is fixed to the lower thigh part (12) by screws.
5. The adaptive knee exoskeleton structure design according to claim 1, characterized in that, The knee joint mechanism (IV) includes: a connecting end cap (14), a servo motor (15), a transmission rod (16), a connecting ligament (17), a tracking active crank (18), and a tracking driven crank (19). The motor end cap (14) is connected by embedding the servo motor (15); the transmission rod (16) connects the motor end cap (14) and the connecting ligament (17); the tracking active crank (18) is located between the lower thigh (12) and the upper calf (20) and is connected by rivets, allowing the two to rotate relative to each other; the tracking driven crank (19) is located at both ends of the lower thigh (12) and the upper calf (20) and is connected by rivets, allowing the two to rotate relative to each other.
6. The adaptive knee exoskeleton structure design according to claim 1, characterized in that, The retractable adjustable calf assembly (V) includes an upper calf portion (20), a calf support (21), and a lower calf portion (22). The upper calf portion (20) and the calf support (21) are fixed by screws; the upper calf portion (20) is connected to the lower calf portion (22) by screws, allowing both to be retracted and adjusted.
7. The adaptive knee exoskeleton structure design according to claim 1, characterized in that, The foot assembly (VI) includes: a servo motor (23), a calf-foot connector (24), a connector 3 (25), a coil spring (26), a foot plate (27), and a retainer (28). The servo motor (23) and the calf-foot connector (24) are connected by the connector 3 (25); the coil spring (26) is embedded in the calf-foot connector (24) and fixed by screws; the foot plate (27) and the calf-foot connector (24) are connected by rivets, allowing them to rotate relative to each other; the retainer (28) is fixed to the foot plate (27) by screws.