Lower limb exoskeleton leg structure based on Bowden cable driving and modular layout

Abstract

The lower limb exoskeleton leg structure based on Bowden cable driving and modular layout comprises hip joint motors and knee joint motors, the hip joint motors are installed on hip joint motor fixing plates through hip joint motor fixing pieces, and the hip joint motor fixing plates are connected with hip joint upper connecting plates and hip joint lower connecting plates; a motor flange is mounted at the output end of the hip joint motor; a motor output shaft is fixed on the motor flange; the other end of the motor output shaft is connected with a knee joint motor, and meanwhile, the motor output shaft transmits power to a thigh rod connecting piece through a transmission bolt; the thigh rod connecting piece is connected with the upper thigh rod, and the upper thigh rod is connected with the lower thigh rod; the other end of the lower thigh rod is connected with a knee joint fixing part, the knee joint fixing part is rotationally connected with a knee joint moving part, the tail end of the knee joint moving part is connected with an upper shank rod, an output shaft of the knee joint motor is fixedly provided with a Bowden cable driving wheel, and the Bowden cable driving wheel drives the knee joint moving part to rotate through a Bowden cable.

Description

Technical Field

[0001] The present invention belongs to the field of exoskeleton robot technology, and specifically relates to an adjustable lower limb exoskeleton structure based on flexible drive and modular design, which is particularly suitable for medical rehabilitation and walking assistance scenarios. Background Art

[0002] In traditional lower limb exoskeleton designs, the hip and knee joint drive systems often limit wear comfort and flexibility due to issues such as bulky size, low transmission efficiency, or complex structure. In existing technologies, knee joints are mostly driven by rigid gears or connecting rods, resulting in uneven weight distribution and difficulty adapting to the natural gait of the human body; the decentralized layout of the hip joint drive module increases the redundant volume of the overall structure. In addition, the exoskeleton length adjustment mechanism often relies on cumbersome mechanical locking devices, making it difficult to quickly adapt to different user needs. How to improve the lightweight, response speed, and human-machine collaboration efficiency of the exoskeleton through compact design and flexible drive technology remains a technical difficulty that needs to be solved urgently. Summary of the Invention

[0003] In order to solve the technical problems existing in the prior art, the present invention proposes a lower limb exoskeleton leg structure based on Bowden cable drive and modular design.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows: The lower limb exoskeleton leg structure based on Bowden cable drive and modular layout includes a hip joint motor fixing plate, a hip joint motor, and a knee joint motor. The hip joint motor is installed on the hip joint motor fixing plate through a hip joint motor fixing piece. The hip joint motor fixing plate is connected to the upper connecting plate of the hip joint and the lower connecting plate of the hip joint to form a stable support structure; a motor flange is installed at the output end of the hip joint motor, and a motor output shaft is fixed on the motor flange to transmit the torque generated by the motor; the other end of the motor output shaft is connected to the knee joint motor, and at the same time, the motor output shaft transmits power to the thigh rod connecting piece through a transmission bolt; the thigh rod connecting piece is connected to the upper thigh rod, and the upper thigh rod is connected to the lower thigh rod; the other end of the lower thigh rod is connected to the knee joint fixing piece, the knee joint fixing piece is rotatably connected to the knee joint movable part, and the end of the knee joint movable part is connected to the upper calf rod, and the knee joint motor output shaft is fixed with a Bowden cable drive wheel, which drives the knee joint movable part to rotate through the Bowden cable. The present invention significantly reduces the volume of the hip by centrally arranging the hip joint motor and the knee joint motor, and at the same time utilizes the flexible transmission characteristics of the Bowden cable to achieve efficient driving of the knee joint.

[0005] As a further technical solution, the motor output shaft includes a first connecting part and a second connecting part. The first connecting part is buckled together with the motor flange. A connecting hole is provided on the first connecting part. The connecting hole is connected to the connecting hole on the motor flange. A connecting ear is provided on the side of the first connecting part and is connected to the transmission bolt. The second connecting part is connected to the knee joint motor.

[0006] As a further technical solution, there is a wire rope channel inside the Bowden cable drive wheel. The wire rope inside the Bowden cable passes through the wire rope channel and is wrapped around once. The center hole in the middle of the Bowden cable drive wheel cooperates with a screw to tighten the wire rope.

[0007] As a further technical solution, limit blocks are symmetrically provided on both sides of the Bowden cable drive wheel. After the steel wire rope inside the Bowden cable passes through the hole of the limit block, it follows the arc structure formed by the outer skin of the Bowden cable and passes through the upper opening of the knee joint fixed part, then goes around the knee joint movable part half a circle and is fixed on the knee joint movable part.

[0008] As a further technical solution, it also includes a knee joint baffle, which is fixed to the knee joint connecting part, and the knee joint connecting part is connected to the knee joint fixing part. A thrust bearing is placed between the knee joint baffle and the knee joint movable part, and between the knee joint movable part and the knee joint fixing part respectively. The two thrust bearings are located in the circular grooves on both sides of the knee joint movable part.

[0009] As a further technical solution, a protruding structure is provided on the movable part of the knee joint for limiting the rotation range of the knee joint.

[0010] As a further technical solution, the hip joint motor fixing piece is connected to the hip joint motor sleeve, and the thigh rod connecting piece is sleeved on the hip joint motor sleeve.

[0011] As a further technical solution, a limit stop is provided on one side of the motor flange. As a further technical solution, an absolute encoder is installed on one side of the knee joint fixator, which is composed of an encoder bracket, an absolute magnetic encoder, small magnetic particles, and a magnetic particle fixing bracket. The encoder fixing bracket is on the knee joint fixator, the absolute magnetic encoder is embedded in the encoder fixing bracket, the small magnetic particles are embedded in the circular holes on the magnetic particle fixing bracket, and the magnetic particle fixing bracket is fixed on the knee joint movable part. When the knee joint movable part rotates, the small magnetic particles will also rotate relative to the absolute magnetic encoder. The absolute magnetic encoder can detect the rotation signal and output the position of the knee joint in real time.

[0012] As a further technical solution, the thigh rod connector is installed on the hip joint motor sleeve, the hip joint motor sleeve is connected to the hip joint motor fixing piece, and a bearing is provided between the thigh rod connector and the hip joint motor sleeve.

[0013] The beneficial effects of the present invention are as follows: 1. The present invention achieves a more compact structural design by integrating the hip joint motor with the knee joint motor; the close arrangement of the two motors effectively reduces space occupancy and reduces the weight of the device. The design method of shortening the distance between the motors can significantly reduce the rotational inertia of the exoskeleton legs, improve the response speed and movement accuracy of the exoskeleton, and has obvious advantages in complex gait control and fine movement coordination; the present invention simplifies the power transmission system by rationally arranging the motor flange, motor output shaft and transmission bolts, reduces the complexity of the transmission part, and improves the stability and durability of the system. By optimizing the layout of the motor and transmission mechanism, the present invention effectively reduces the volume of the joint assembly, making the device more adaptable to the human body structure and improving the wearing experience. It is particularly suitable for rehabilitation treatment and long-term wear; the flexible transmission of the Bowden cable reduces energy loss and cooperates with the dual-bearing support to achieve low-friction, high-response joint movement.

[0014] 2. The centralized dual-motor layout and nested thigh rod design of the present invention significantly reduce structural redundancy and improve wearing comfort.

[0015] 3. The modular hole structure of the upper thigh bar and the lower thigh bar of the present invention supports quick length adjustment to adapt to the needs of users of different body shapes.

[0016] 4. The dual mechanical limit mechanism for the hip / knee joint effectively prevents excessive movement and reduces the risk of accidents. Specifically, a protruding structure on the knee joint's movable part limits the range of rotation of the knee joint. A limit block is provided on one side of the motor flange to prevent the motor output shaft from moving beyond the natural range of motion of the human hip joint, thereby avoiding possible injury or safety accidents.

[0017] 5. Precise control: The magnetic encoder provides real-time feedback of joint angles, providing high-precision closed-loop data support for gait coordination. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Illustration of the leg structure Figure 1 ; Figure 2 Illustration of the leg structure Figure 2 ; Figure 3 Illustration of the leg structure Figure 3 ; Figures 4 (a) and 4 (b) are partial schematic diagrams of the knee joint and leg structure; Figure 5 A schematic diagram of the hip joint; Figure 6 (a) and Figure 6 (b) are schematic diagrams of the active parts of the knee joint; Figure 7 is a schematic diagram of a knee joint fixation device; Figure 8 This is a schematic diagram of the Bowden cable limit block; Figure 9 (a) and Figure 9 (b) are schematic diagrams of the Bowden cable drive wheel; Figure 10 is a schematic diagram of the motor output shaft; Figure 11 is a schematic diagram of the hip joint motor sleeve; Figure: 1. Hip joint motor fixture; 2. Thigh rod connector; 3. Upper thigh rod; 4. Lower thigh rod; 5. Knee joint fixture; 6. Knee joint movable member; 7. Upper calf rod; 8. Magnetic particle fixing bracket; 9. Hip joint motor; 10. Hip joint lower connecting plate; 11. Hip joint motor fixing plate; 12. Hip joint upper connecting plate; 13. Limit block; 14. Motor flange; 15. Motor output shaft; 16. Knee joint motor; 17. Knee joint baffle; 18. Drive bolt; 19. Bowden cable drive wheel; 20. Small magnetic particles; 21. Absolute magnetic encoder; 22. Encoder fixing bracket; 23. Limit block; 24. Hip joint motor sleeve; 25. Bearing; 26. Bearing; 27. Bearing retaining ring; 28. Nut; 29. ​​Bowden cable; 6-1. Limiting structure; 6-1. Hole; 6-2. Hole; 6-3. Protruding structure; 15-1. First connecting portion; 15-2. Second connecting portion; 15-3. Connecting ear; 24-1. Sleeve; 24-2. Flange; 19-1. Wire rope channel; 19-2. Center hole; DETAILED DESCRIPTION It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0019] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise clearly indicated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprising" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations; For the convenience of description, if the words "up", "down", "left" and "right" appear in the present invention, they only indicate that they are consistent with the up, down, left and right directions of the drawings themselves, and do not limit the structure. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0020] As introduced in the background technology, in order to solve the deficiencies in the existing technology, the present invention proposes a lower limb exoskeleton leg structure based on Bowden cable drive and modular layout.

[0021] The present invention discloses a lower limb exoskeleton leg structure based on Bowden cable drive and modular layout, such as Figure 1 、、 Figure 2 、 Figure 3 As shown, it includes: hip joint motor 9, knee joint motor 16; The hip joint motor 9 is used to drive the movement of the pitch angle of the hip joint. The hip joint motor 9 is fixed on the hip joint motor fixing part 1. The hip joint motor fixing part 1 is respectively connected to the hip joint motor fixing plate 11, the hip joint upper connecting plate 12, and the hip joint lower connecting plate 10. The hip joint upper connecting plate 12, the hip joint lower connecting plate 10 and the hip joint motor fixing plate 11 are connected to form a whole, which is used to connect other hip joints.

[0022] The end of the output shaft of the hip joint motor 9 is connected to a motor flange 14, to which is connected a motor output shaft 15. The motor output shaft 15 is a plate-shaped structure (as shown in Figures 9(a) and 9(b)). The side of the motor output shaft 15 is connected to the thigh rod connector 2 via a transmission bolt 18 and a nut 28. The lower part of the motor output shaft 15 is connected to the knee joint motor 16. The hip joint motor 9 transmits the power to the thigh rod connector 2 through the motor flange, motor output shaft, and transmission bolts; the thigh rod connector 2 is connected to the upper thigh rod 3, and the upper thigh rod 3 is connected to the lower thigh rod 4; the other end of the lower thigh rod 4 is connected to the knee joint fixing part 5, and the knee joint fixing part 5 is as shown in FIG. Figure 7 As shown in FIG6( a ) and FIG6 ( b ), the knee joint movable member 6 can rotate around the knee joint fixed member 5 . The knee joint movable member 6 is shown in FIG6( a ) and FIG6( b ). The end of the knee joint movable member 6 is connected to the upper shank rod 7 . The knee joint movable member 6 is driven by the tension at both ends of the Bowden cable 29 .

[0023] Furthermore, in this embodiment, a stopper 13 is provided on one side of the motor flange 14 to prevent the motor output shaft from moving beyond the natural range of motion of the human hip joint, thereby avoiding possible injury or safety accidents. The stopper is symmetrically structured, with both ends acting as limiters and secured to the hip joint motor mounting plate 11. This ensures that the hip joint's range of motion does not exceed the human body's natural range of motion, preventing joint injury or equipment damage caused by excessive movement.

[0024] Furthermore, the knee joint motor 16 is fixed to the motor output shaft of the hip joint motor 9, and a Bowden cable drive wheel 19 is fixed to the output shaft of the knee joint motor 16. The structure of the Bowden cable drive wheel 19 is shown in Figures 9 (a) and 9 (b). There is a wire rope channel 19-1 inside. The wire rope inside the Bowden cable 29 can pass through the middle and be wound around once. Then, the center hole 19-2 in the middle of the Bowden cable drive wheel 19 cooperates with a screw to prevent a screw from tightening the wire rope of the Bowden cable 29 and preventing the wire rope from sliding relative to each other. The wire rope passes through the middle opening of the Bowden cable limit block 23. The limit block is as shown in FIG. Figure 8 shown.

[0025] Furthermore, the Bowden cable 29 is constructed from an internal steel wire rope and an external sheath of a certain hardness. When forces are applied to both ends, the sheath maintains a certain shape. One end of the Bowden cable 29 is fixed to the opening of the stop block 23, while the other end is fixed to two circular holes in the upper portion of the knee joint fastener 5. The Bowden cable 29 maintains an arc shape, while the steel wire rope slides within the sheath of the cable 29. The structure of the knee joint is shown in Figures 6(a) and 6(b).

[0026] The two ends of the steel wire rope inside the Bowden cable 29 pass through the holes of the two limit blocks 23, follow the arc structure formed by the outer skin of the Bowden cable 29, pass through the upper opening of the knee joint fixed component 5, and then wrap half a circle around the knee joint movable component 6 and fix it to the knee joint movable component 6. The knee joint movable component 6 has two openings, namely hole 6-1 and hole 6-2, which respectively fix the two ends of the steel wire rope. The two limit blocks 23 are symmetrically arranged on both sides of the Bowden cable drive wheel 19; the structure of the limit blocks 23 can be seen in FIG. Figure 8 ; The knee joint motor 16 drives the Bowden cable drive wheel 19 to rotate, and the Bowden cable drive wheel 19 pulls the knee joint movable part 6 to rotate relative to the knee joint fixed part 5 through the Bowden cable wire rope.

[0027] Furthermore, the device includes a knee baffle 17, which is fixed to the knee fixed component 5. This baffle serves to form a revolute pair for the knee joint and to connect to other structures. Thrust bearings are placed between the knee baffle 17 and the knee movable component 6, and between the knee movable component 6 and the knee fixed component 5. The two thrust bearings are located in circular grooves on either side of the knee movable component 6 to reduce friction during rotation. A protrusion 6-3 on the knee movable component 6 limits the range of knee joint rotation, preventing the knee joint from exceeding its limits and potentially causing a dangerous movement.

[0028] Furthermore, the upper thigh rod 3 in this embodiment is a hollow structure, with holes evenly opened on the upper thigh rod 3. The outer diameter of the lower thigh rod 4 is slightly smaller than the inner diameter of the upper thigh rod 3. The lower thigh rod 4 is inserted into the upper thigh rod 3. The lower thigh rod 4 is also opened in the same way as the upper thigh rod 3. The holes of the two are arranged in the same way. By adjusting the alignment of the holes on the two rods, the length of the entire thigh rod can be adjusted. The upper thigh rod and the lower thigh rod are fixed by bolts passing through their holes.

[0029] Furthermore, two bearings are placed between the thigh rod connector 2 and the hip joint motor 9 to reduce the friction between the two when they rotate. The bearings are sleeved on the motor sleeve, and the hip joint motor 9 is located inside the motor sleeve. The motor sleeve is connected to the hip joint motor fixing part. A bearing retaining ring is placed between the two bearings to position and constrain the two bearings.

[0030] Specifically, the structure of the motor output shaft 15 is as follows Figure 10 As shown, the motor output shaft 15 includes a first connecting part 15-1 and a second connecting part 15-2. The first connecting part 15-1 is snapped together with the motor flange 14. A connecting hole is provided on the first connecting part 15-1, and the connecting hole is connected to the connecting hole on the motor flange 14. A connecting ear 15-3 is provided on the side of the first connecting part 15-1, and a connecting hole is provided on the connecting ear 15-3, which is connected to the transmission bolt. The second connecting part 15-2 is connected to the knee joint motor 16, and the second connecting part 15-2 is a semicircular connecting part; the first connecting part 15-1 is a semicircular connecting part, and the cross-sectional shape of the first connecting part 15-1 is L-shaped.

[0031] Furthermore, a limit stopper 13 is fixed on one side of the motor flange 14. The limit stopper 13 is used to limit the rotation range of the motor output shaft 15 to prevent the rotation from exceeding the limit of human hip joint movement and causing danger. The limit stopper 13 can achieve upper and lower limits.

[0032] Furthermore, an absolute value encoder is installed on one side of the knee joint fixator 5, which is composed of an encoder fixing bracket 22, an absolute value magnetic encoder 21, small magnetic particles 20, and a magnetic particle fixing bracket 8. The encoder fixing bracket 22 is on the knee joint fixator, the absolute value magnetic encoder 21 is embedded in the encoder fixing bracket 22, the small magnetic particles 20 are embedded in the circular hole on the magnetic particle fixing bracket 8, and the magnetic particle fixing bracket 8 is fixed on the knee joint movable part. When the knee joint movable part rotates, the small magnetic particles will also rotate relative to the absolute value magnetic encoder. The absolute value magnetic encoder can detect the rotation signal and output the position of the knee joint in real time.

[0033] As a further technical solution, the hip joint motor fixing part 1 includes a fixing tube, on which a bolt hole is provided, and the bolt hole is used to connect with the hip joint motor. Two connecting plates extend from the outer circle of the fixing tube, and the connecting plates are connected to the hip joint motor fixing plates.

[0034] As a further technical solution, a hip joint motor sleeve 24 is also included, such as Figure 11 As shown, the hip joint motor sleeve 24 includes a sleeve 24-1, a flange 24-2 is provided at one end of the sleeve 24-1, and a circle of connecting holes is opened on the flange 24-2, which is connected to the hip joint motor fixing part 1 to form a whole; bearings 25 and bearings 26 are provided between the hip joint motor sleeve 24 and the thigh rod connecting part 2; a bearing retaining ring 27 is provided between the bearings 25 and the bearings 26; the bearings 25, 26 and the bearing retaining ring 27 are all mounted on the hip joint motor sleeve 24 to form a stable transmission system.

[0035] The working principle of the present invention is as follows: The hip joint motor transmits power to the thigh rod connector via a flange and output shaft, driving the leg's pitch motion. Limit blocks constrain its rotation range to prevent overload. The knee joint motor drives the Bowden cable drive wheel to tighten or release the cable. Flexible traction causes the knee joint's movable parts to rotate around the fixed parts, simulating human knee flexion and extension. The curved path design of the Bowden cable's outer sheath optimizes the direction of force transmission, while the guiding action of the limit blocks reduces cable slippage. The nested structure of the thigh rod is fixed to the aligned holes via bolts, enabling stepless length adjustment. An absolute magnetic encoder detects magnetic particle displacement to provide real-time feedback on joint angles, providing high-precision data for motion control.

[0036] The present invention has the following advantages: Compact and Lightweight: The centralized dual-motor layout and nested thigh-bar design significantly reduce structural redundancy and enhance wearer comfort. Efficient Drive: The flexible Bowden cable transmission reduces energy loss, and the dual-bearing support achieves low-friction, highly responsive joint movement.

[0037] Adaptive adjustment: The modular hole structure supports quick length adjustment to suit the needs of users of different body shapes.

[0038] Safety redundancy: The dual mechanical limit mechanisms of the hip / knee joints effectively prevent excessive movement and reduce accident risks.

[0039] Precise control: The magnetic encoder provides real-time feedback of joint angles, providing high-precision closed-loop data support for gait coordination.

[0040] This invention significantly reduces the size of the hip joint by centrally arranging the hip and knee joint motors. It also leverages the flexible transmission characteristics of the Bowden cable to achieve efficient knee joint actuation. The hip joint utilizes a double-layer connecting plate and a limit block integrated solution, ensuring pitch motion accuracy while limiting range of motion to enhance safety. The thigh bar utilizes a nested, adjustable structure, enabling rapid length adjustment through hole alignment. The knee joint utilizes the synergistic effect of the Bowden cable drive wheel and the limit block, combined with dual thrust bearings to reduce frictional resistance. An absolute magnetic encoder is introduced to monitor joint angles in real time, ensuring precise motion control.

[0041] Finally, it should be noted that relational terms such as first and second are merely used to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0042] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A lower limb exoskeleton leg structure based on Bowden cable drive and modular layout, characterized by: It includes a hip joint motor and a knee joint motor. The hip joint motor is installed on a hip joint motor fixing plate through a hip joint motor fixing part. The hip joint motor fixing plate is connected to the upper connecting plate of the hip joint and the lower connecting plate of the hip joint to form a stable supporting structure; a motor flange is installed at the output end of the hip joint motor, and a motor output shaft is fixed on the motor flange to transmit the torque generated by the motor; the other end of the motor output shaft is connected to the knee joint motor, and at the same time, the motor output shaft transmits power to the thigh rod connecting part through a transmission bolt; the thigh rod connecting part is connected to the upper thigh rod, and the upper thigh rod is connected to the lower thigh rod; the other end of the lower thigh rod is connected to a knee joint fixing part, the knee joint fixing part is rotatably connected to the knee joint movable part, and the end of the knee joint movable part is connected to the upper calf rod, and a Bowden cable drive wheel is fixed to the knee joint motor output shaft, and the Bowden cable drive wheel drives the knee joint movable part to rotate through the Bowden cable.

2. The lower limb exoskeleton leg structure based on Bowden cable drive and modular layout according to claim 1, characterized in that: The motor output shaft includes a first connecting part and a second connecting part. The first connecting part is buckled together with the motor flange. A connecting hole is provided on the first connecting part. The connecting hole is connected to the connecting hole on the motor flange. A connecting ear is provided on the side of the first connecting part and is connected to the transmission bolt. The second connecting part is connected to the knee joint motor.

3. The lower limb exoskeleton leg structure based on Bowden cable drive and modular layout according to claim 1, characterized in that: The Bowden cable drive wheel has a wire rope channel inside, and the wire rope inside the Bowden cable passes through the wire rope channel and is wound around once. The center hole in the middle of the Bowden cable drive wheel cooperates with a screw to tighten the wire rope.

4. The lower limb exoskeleton leg structure based on Bowden cable drive and modular layout according to claim 1, characterized in that: Limit blocks are symmetrically arranged on both sides of the Bowden cable driving wheel. After the steel wire rope inside the Bowden cable passes through the hole of the limit block, it follows the arc structure formed by the outer skin of the Bowden cable, passes through the upper opening of the knee joint fixed part, and then wraps around the knee joint movable part half a circle and is fixed on the knee joint movable part.

5. The lower limb exoskeleton leg structure based on Bowden cable drive and modular layout according to claim 1, characterized in that: It also includes a knee joint baffle, which is fixed to the knee joint connecting part, and the knee joint connecting part is connected to the knee joint fixing part. A thrust bearing is placed between the knee joint baffle and the knee joint movable part, and between the knee joint movable part and the knee joint fixing part respectively. The two thrust bearings are located in the circular grooves on both sides of the knee joint movable part.

6. The lower limb exoskeleton leg structure based on Bowden cable drive and modular layout according to claim 1, characterized in that: The knee joint movable part is provided with a protruding structure for limiting the rotation range of the knee joint.

7. The lower limb exoskeleton leg structure based on Bowden cable drive and modular layout according to claim 1, characterized in that: The hip joint motor fixing piece is connected to the hip joint motor sleeve, and the thigh rod connecting piece is sleeved on the hip joint motor sleeve.

8. The lower limb exoskeleton leg structure based on Bowden cable drive and modular layout according to claim 1, characterized in that: A limit block is provided on one side of the motor flange.

9. The lower limb exoskeleton leg structure based on Bowden cable drive and modular layout according to claim 1, characterized in that: An absolute encoder is installed on one side of the knee joint fixation.

10. The lower limb exoskeleton leg structure based on Bowden cable drive and modular layout according to claim 1, characterized in that: The thigh rod connecting piece is installed on the hip joint motor sleeve, the hip joint motor sleeve is connected to the hip joint motor fixing piece, and a bearing is provided between the thigh rod connecting piece and the hip joint motor sleeve.

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