Rope-driven lower limb rehabilitation robot with knee joint wearing mechanism

Abstract

The invention discloses a rope-driven lower limb rehabilitation robot with a knee joint wearing mechanism, and relates to the field of rehabilitation medical instruments. The robot comprises a driving module, a rope transmission module, a knee joint wearing mechanism and a control module, the knee joint wearing mechanism adopts a multi-connecting-rod hinge mechanism for connecting thigh and shank brackets, and through precise kinematics design, a mechanical rotation center dynamically simulates the change of an instantaneous rotation center of a knee joint of a human body, so that extremely high motion bionic property is realized while the stability of a rigid structure is kept. By combining rope-driven lightweight compliance and high-precision force control, the system can provide efficient, natural and safe lower limb rehabilitation training.

Description

Technical Field

[0001] This invention relates to the field of rehabilitation medical device technology, specifically to a wearable rehabilitation robot for assisting or training patients with lower limb motor dysfunction, and particularly to a lower limb rehabilitation robot system that is cable-driven and equipped with a knee joint wearing mechanism. Background Technology

[0002] Lower limb rehabilitation robots are important tools to help patients with stroke, spinal cord injury, and other conditions regain their walking function. Current lower limb rehabilitation robots mainly fall into two categories: one is large, floor-standing exoskeleton robots, which typically use rigid linkage structures and rotary joint drives. These robots suffer from problems such as heavy weight, high cost, and difficulty in precisely aligning their motion axes with the human physiological axis, making them unsuitable for daily rehabilitation training or home settings. The other category is local joint assistive devices, but their drive mechanism often acts directly on the side of the limb, potentially generating unnecessary lateral forces and affecting the naturalness and comfort of training.

[0003] In pursuit of lightweight design and improved human-machine compatibility, rope-driven rehabilitation robots have emerged. This technology places heavy components such as drive motors on a fixed platform away from the limbs, transmitting tension to the limbs solely through lightweight, flexible ropes. This significantly reduces the inertia of moving parts, improving system compliance and safety. However, the practical application of rope-driven technology faces a core challenge: how to design end effectors, i.e., wearable mechanisms, to address the force transmission issue between the ropes and the human joints.

[0004] Most existing solutions use simple straps or simple hinges combined with rigid links. These designs generally have the following problems: (1) Low force transmission efficiency: The direction of the rope tension is fixed and cannot be dynamically adjusted with the flexion and extension of the knee joint, resulting in a small effective auxiliary force and unnecessary skin shear force; (2) Poor wearing stability: The straps are prone to slippage during movement, changing the lever arm and affecting control accuracy; (3) Insufficient comfort: Rigid components or concentrated force points are prone to compressing soft tissues and nerves and blood vessels; (4) Unable to adapt to physiological movement: When the human knee joint flexes and extends in the sagittal plane, it is accompanied by slight adduction / abduction and rotation. Simple single-axis hinges or pure soft straps cannot achieve the decoupling of this multi-degree-of-freedom movement, either restricting natural movement or introducing movement interference.

[0005] Therefore, although rope-driven technology has advantages in principle, there is a lack of a dedicated knee-joint wearable mechanism that can simultaneously meet the requirements of efficient force transmission, dynamic motion adaptation, and stable and comfortable wear. This severely restricts the promotion and application of this technology in clinical and home settings. Summary of the Invention

[0006] In view of this, the present invention provides a cable-driven lower limb rehabilitation robot with a knee joint wearing mechanism. The robot has a simple structure, is comfortable to wear, and is smoothly driven, which can more naturally assist patients in performing flexion and extension rehabilitation training of their lower limbs.

[0007] Therefore, the present invention provides the following technical solution:

[0008] This invention provides a cable-driven lower limb rehabilitation robot with a knee joint wearing mechanism, comprising: The drive module includes six independent drive units; The rope drive module includes six flexible ropes; each flexible rope is independently controlled by a drive unit; one end of each flexible rope is connected to the drive unit, and the other end is connected to a connection point on the thigh or calf support of the knee joint wearing mechanism. The knee joint wearable mechanism includes a thigh support, a calf support, and two sets of multi-link hinge mechanisms; the configuration of the multi-link hinge mechanisms is designed such that the instantaneous relative rotation center between the thigh support and the calf support changes with the flexion and extension angle; the thigh support and the calf support are provided with six connection points for guiding and connecting flexible ropes; A control module is used to control the drive module.

[0009] Furthermore, the multi-link hinge mechanism is a six-bar linkage mechanism; the six-bar linkage mechanism includes a first link, a second link, a third link, a fourth link, a fifth link, and a sixth link connected sequentially via revolute joints; wherein, the second link and the fourth link are triangular link assemblies, the first end of the first link is connected to two fixed points on the thigh support; the first end of the sixth link is connected to two fixed points on the calf support via hinge shafts; the first end of the second link is hinged to the second end of the first link, and the first end of the fourth link is hinged to the third end of the first link; the second end of the second link is hinged to the first end of the third link, the second end of the fourth link is hinged to the second end of the third link, the third end of the second link is hinged to the first end of the fifth link, the second end of the fifth link is hinged to the second end of the sixth link, and the third end of the fourth link is hinged to the third end of the sixth link.

[0010] Furthermore, the lengths of each link and the positions of the hinge points of the six-bar linkage are configured such that the relative rotation center trajectory between the thigh support and the calf support coincides with the average trajectory of the instantaneous rotation center when the human knee joint is naturally flexed and extended within a preset angle range.

[0011] Furthermore, the thigh support is provided with four connection points: a first connection point on the proximal anterior side, a second connection point on the proximal posterior side, a third connection point on the distal anterior side, and a fourth connection point on the distal posterior side; at least four of the aforementioned flexible ropes act independently on the first to fourth connection points to provide multi-directional suspension and control of the thigh. The lower leg support has two connection points, namely the fifth connection point on the proximal anterior side and the sixth connection point on the proximal posterior side; at least two of the flexible ropes act on the fifth connection point and the sixth connection point respectively to synergistically generate knee flexion or extension torque.

[0012] Furthermore, each drive unit includes a servo motor, a ball screw mechanism driven by the servo motor, a movable stage connected to the ball screw mechanism, a linear guide rail guiding the movable stage, and a tension sensor disposed on the movable stage; one end of the flexible rope is fixed to the tension sensor.

[0013] Furthermore, the control module is configured such that the PLC and motor servo system receive IMU sensor signals from the knee joint wearable mechanism and tension signals from the tension sensor of the drive module, and perform closed-loop control of the drive module based on the motion sensor signals and the tension signals.

[0014] Furthermore, the rope drive module also includes a Bowden cable sleeve, through which the flexible rope passes.

[0015] Furthermore, the robot also includes an outer frame, including a bottom support frame, side columns and a top beam. The components are rigidly connected to each other by corner brackets and fasteners to form a stable cuboid cage frame.

[0016] Furthermore, drive and control boxes are installed on the bottom two sides of the outer frame to accommodate the drive module and control module, respectively; mounting positions are reserved on the side columns and crossbeams to fix the guides of the rope transmission module and the mounting base of the weight reduction device, providing mechanical support and installation benchmark for the whole machine.

[0017] Furthermore, it also includes: a weight-reducing device installed on the outer frame, the weight-reducing device including a suspension strap for wearing on the patient's torso.

[0018] The beneficial effects of this invention are as follows: Comfortable to wear and fits well: Through a specially designed rigid multi-link hinge mechanism, the mechanical rotation center can dynamically fit the instantaneous rotation center change of the human knee joint, fundamentally eliminating human-machine motion interference, making assisted movement extremely natural, and greatly improving comfort and safety.

[0019] Efficient and precise force transmission: Combining a high-precision linear drive unit with direct tension measurement, it achieves independent, real-time closed-loop control of the tension of each rope, thereby enabling the precise application of biomechanically compliant auxiliary torque or the provision of compliant resistance training.

[0020] Lightweight and safe system: The rope drive transfers the main weight to the waist, reducing the load on the legs; the combination of mechanical and electronic limit switches, along with the flexible buffer of the Bowden line itself, constitutes a multi-layered safety protection.

[0021] Reliable and durable structure: Compared with flexible compensation mechanisms, rigid multi-link structures are more robust and have a longer lifespan. They can provide a clear and stable force transmission path, ensuring reliability for long-term use. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the rope-driven lower limb rehabilitation robot and its wearable device in an embodiment of the present invention; Figure 2 This is a three-dimensional structural diagram of the knee joint wearing mechanism in an embodiment of the present invention; Figure 3 This is a simplified diagram illustrating the kinematic principle of the six-bar linkage in an embodiment of the present invention. Figure 4 This is a schematic diagram of the internal structure of the driving unit in an embodiment of the present invention; Figure 5 This is a schematic diagram of a high-precision linear drive unit in an embodiment of the present invention. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] like Figure 1 As shown, this embodiment of a cable-driven lower limb rehabilitation robot with a knee joint wearing mechanism mainly includes: a drive module 1, a cable transmission module 2, a knee joint wearing mechanism 3, a control module 4, an outer frame 5, and a weight-reducing device 6. The drive module 1 and control module 4 are integrated and installed in a drive and control box at the lower part of the outer frame 5; one end of the cable transmission module 2 is connected to the drive module 1, and the other end is connected to the knee joint wearing mechanism 3; the knee joint wearing mechanism 3 is worn by the user's lower limbs, and the weight-reducing device 6 is installed at the top of the outer frame 5 and connected to the user's torso via a suspension strap 61 to achieve weight reduction and support.

[0027] The outer frame 5 is an integral aluminum profile support frame structure, including a bottom support frame, side columns, and a top crossbeam. The components are rigidly connected by corner brackets and fasteners to form a stable cuboid cage frame. The drive and control boxes are installed on the bottom two sides of the outer frame 5 to house the drive module 1 and the control module 4, respectively. The side columns and crossbeams have reserved mounting positions for fixing the guide components of the rope transmission module 2 and the mounting base of the weight reduction device 6, providing mechanical support and installation benchmarks for the entire machine.

[0028] like Figure 2As shown, the knee joint wearing mechanism 3 is a wearable rigid support structure adapted to the human lower limbs, including a thigh support 31 that conforms to the thigh, a calf support 32 that conforms to the calf, and two sets of hinged six-bar mechanisms 33. The thigh support 31 and calf support 32 are made of breathable nylon straps and composite PLE sheet, are adjustable, and are fixed to the user's thigh and calf respectively. The hinged six-bar mechanisms 33 are used to connect the thigh support 31 and calf support 32. One set of hinged six-bar mechanisms 33 connects the left side of the thigh support 31 and the left side of the calf support 32, and the other set connects the right side of the thigh support 31 and the right side of the calf support 32, corresponding to the position of the human knee joint, and can rotate synchronously with the user's knee joint. The end of the thigh support 31 and calf support 32 closest to the human knee joint is the proximal end, and the end furthest from the human knee joint is the distal end. The side corresponding to the front of the thigh and the front of the calf is the anterior side, and the side corresponding to the back of the thigh and the back of the calf is the posterior side. The thigh support 31 has four connection points: a first connection point 311a on the proximal anterior side, a second connection point 311b on the proximal posterior side, a third connection point 311c on the distal anterior side, and a fourth connection point 311d on the distal posterior side. The calf support 32 has a fifth connection point 321a on the proximal anterior side and a sixth connection point 321b on the proximal posterior side. These connection points can be in the form of guide locks or connecting holes, and are respectively connected to the end of the traction rope of the rope transmission module 2, so that each traction rope can apply tension to the wearing mechanism from different directions, thereby driving the user's lower limb to perform rehabilitation training movements. Furthermore, the knee joint wearing mechanism 3 can be adjusted according to the user's limb size to fit users of different body types, ensuring the fit and stability of the wearing device.

[0029] Figure 3As shown, the six-bar linkage 33 is formed by six aviation aluminum alloy links (first link 331, second link 332, third link 333, fourth link 334, fifth link 335, and sixth link 336) hinged together by a revolute joint. The first link 331 is an L-shaped link assembly, while the second link 332 and fourth link 334 are triangular link assemblies. Specifically, the first end of the first link 331 is connected to two fixed points on the thigh support 31. The first end of the sixth link 336 is connected to two fixed points on the lower leg support 32 via hinge shafts. The first end of the second link 332 is hinged to the second end of the first link 331 (point B), and the first end of the fourth link 334 is hinged to the third end of the first link 331 (point A). The second end of the second link 332 is hinged to the first end of the third link 333 (point C), the second end of the fourth link 334 is hinged to the second end of the third link 333 (point D), the third end of the second link 332 is hinged to the first end of the fifth link 335 (point G), the second end of the fifth link 335 is hinged to the second end of the sixth link 336 (point F), and the third end of the fourth link 334 is hinged to the third end of the sixth link 336 (point E).

[0030] The instantaneous center of rotation (IRC) of the human knee joint moves along an approximately "J"-shaped curve during flexion and extension (gradually moving forward from the posterior femoral condyle in extension to the anterior femoral condyle in flexion). The hinged six-bar linkage 33 is a single-degree-of-freedom planar six-bar linkage, whose relative motion is uniquely determined by the lengths of each link and the positions of the hinge points. By rationally configuring the relative positions of each point and the lengths of each link, when the mechanism moves, the trajectory of the instantaneous relative center of rotation P between the thigh support 31 and the lower leg support 32 approximates the physiological ICR trajectory of the human body.

[0031] Implementation Principle: When the thigh support 31 and the lower leg support 32 rotate relative to each other, the aforementioned parameter configuration forces the lower leg support 32 to undergo a slight translational motion during rotation, consistent with the rolling-sliding composite motion of the femoral condyle on the tibial plateau during knee flexion and extension. Therefore, the instantaneous rotation center P of the mechanism is no longer fixed at a single point, but moves along a curve approximating the physiological IRC height, thus achieving accurate simulation of multi-center knee joint motion under rigid structural constraints. This design, while ensuring all connections are rigid revolute pairs, simulates the complex multi-center motion characteristics of the knee joint with high precision using a single degree of freedom, fundamentally eliminating motion interference and skin shear forces caused by traditional single-axis hinges.

[0032] After optimization calculations, a set of typical geometric parameters were obtained as follows: The length of the first link 331 is 45.15 mm; the length of BC in the second link 332 is 38.37 mm; the length of BG in the second link 332 is 58.56 mm; the length of BG in the second link 332 is... φ 2. Angle: 24.08°; Length of third link 333: 18.21 mm; Length of AE in fourth link 334: 95.42 mm; Length of AD in fourth link 334: 34.26 mm; Length of fourth link 334... φ 1. Angle: 48.01°; 5th link 335 length: 17.73 mm; 6th link 336 length: 61.84 mm.

[0033] like Figure 5 As shown, the rope transmission module 2 includes six independent flexible ropes 21 and corresponding guide devices. Each guide device is fixed to the side column of the outer frame 5. The guide device can be a pin with a small hole through which the flexible rope 21 passes. One end is connected to the connection point of the thigh support 31 or the lower leg support 32, and the other end is connected to the drive unit 11. The layout of the six flexible ropes 21 is as follows: Thigh suspension and control ropes (four ropes): One end of the first to fourth ropes is fixed to the tension sensor 115 of the four independent drive units 11 via the guide device, and the other end is connected to the first to fourth connection points (311a, 311b, 311c, 311d) of the thigh support 31, respectively. These four ropes work together to suspend the weight of the robot system on the outer frame 5, maintain the stable fit of the thigh support 31, and assist in adjusting the thigh posture. Knee joint main drive ropes (two ropes): The fifth and sixth ropes are the core ropes for driving the flexion and extension of the knee joint. Taking the fifth rope (knee extension rope) as an example, one end is fixed to a drive unit 11, and after being guided by a guide mechanism, it is finally fixed to the fifth connection point 321a of the lower leg support 32. The sixth rope (knee flexion rope) has a symmetrical path and is fixed to the sixth connection point 321b. When the drive unit tightens the fifth rope, it generates a torque that causes the lower leg to swing forward, assisting in knee extension; when the sixth rope is tightened, it assists in knee flexion.

[0034] By coordinating and controlling the tension of six ropes, full-range assisted movement of the human lower limbs can be achieved.

[0035] like Figure 4 , Figure 5As shown, drive module 1 and control module 4 are integrated and installed in the drive and control box 200 at the bottom of the outer frame 5. Drive module 1 and control module 4 are electrically connected and together constitute the power and control hub of the robot. Drive module 1 includes six independent drive units 11, which provide power output to the system and realize independent traction control of each rope. Six independent drive units 11 are installed side by side in the drive and control box 200. Each drive unit 11 includes: a servo motor 111, whose output shaft is connected to the lead screw of ball screw mechanism 112 through a coupling. The nut of ball screw mechanism 112 drives the moving stage 113 to slide along the linear guide rail 114. The two ends of the linear guide rail 114 are equipped with rigid limit baffles. An S-shaped tension sensor 115 is installed on the moving stage 113. The outer sheath of Bowden cable sleeve 22 is fixed to the box, and its inner core tube opening is aligned with the tension sensor 115. One end of the flexible rope 21 is fastened to the measuring end of the tension sensor 115 via a threaded connector. The motion of the servo motor 111 is precisely converted into the extension and retraction of the flexible rope 21 and the change in tension.

[0036] The control module 4 includes a main control unit, which is connected to the host computer for communication. It receives control commands and outputs control signals to each servo motor 111 in the drive module 1, thereby controlling the rotation of each servo motor 111 in the drive module 1. At the same time, the main control unit receives real-time tension signals from each tension sensor 115 in the drive module 1, as well as the relative angle and spatial attitude signals of the thigh and lower leg measured by the inertial measurement unit (IMU) embedded in the thigh support 31 and the lower leg support 32.

[0037] In "Assist Mode," the controller calculates the knee joint torque required to complete a preset ideal gait angle trajectory (e.g., a trajectory curve with gait cycle percentage as the x-axis and knee joint angle as the y-axis), combined with the actual knee joint angle and angular velocity fed back by the IMU in real time, using an inverse dynamics model. Then, based on the mapping relationship between cable tension and joint torque, the target tension values ​​for the fifth and sixth cables are calculated. The controller employs an impedance-admittance control algorithm to drive the servo motor 111 to accurately track this target tension, achieving smooth and natural motion assistance. Simultaneously, based on the thigh posture signal fed back by the IMU, the controller coordinates the adjustment of the tension of the first to fourth cables to ensure the overall stability of the wearable mechanism at each stage of gait.

[0038] In "Training Mode," the user actively exerts force to move, and the controller monitors the knee joint angle and angular velocity in real time via the IMU. When the system detects that the user's movement deviates from the preset trajectory range or the angular velocity exceeds a set threshold, it provides variable resistance by adjusting the tension of the fifth and sixth ropes. At the same time, the controller dynamically adjusts the tension of the first to fourth ropes based on the posture changes fed back by the IMU to maintain a stable fit of the wearable mechanism and prevent slippage caused by the inertial force generated by active movement.

[0039] The weight-reduction device 6 is installed on the top crossbeam of the outer frame 5 and includes a mounting base, an elastic adjustment component, and a suspension strap 61. The mounting base is fixed to the top crossbeam of the outer frame 5. The elastic adjustment component is located between the mounting base and the suspension strap 61 and can provide adjustable upward tension to support part of the user's weight. The suspension strap 61 is a wearable flexible strap that fits the human torso. It is worn and fixed to the user's chest or upper torso to transfer part of the user's weight to the outer frame 5, thereby reducing the load pressure on the lower limbs and assisting the user in rehabilitation training while in a weight-reduction state.

[0040] During operation, the user wears the knee joint wearing mechanism 3 and suspension belt 61. The host computer sends a control mode selection command to the control module 4. In the auxiliary mode or training mode, the control module 4 drives the servo motor of the drive module 1 to rotate, which drives the knee joint wearing mechanism 3 to move through the rope transmission module 2, thereby assisting the user's lower limbs to complete knee joint rehabilitation training movements. At the same time, the tension sensor 115 collects the rope tension signal in real time and feeds it back to the control module 4 to realize closed-loop control of traction force. With the weight reduction support of the weight reduction device 6, a safe and controllable rehabilitation training environment is provided for the user.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cable-driven lower limb rehabilitation robot with a knee joint wearing mechanism, characterized in that, include: The drive module (1) includes six independent drive units (11). The rope drive module (2) includes six flexible ropes (21); each flexible rope (21) is independently controlled by a drive unit (11); one end of the flexible rope (21) is connected to the drive unit (11), and the other end is connected to the connection point on the thigh support (31) or calf support (32) of the knee joint wearing mechanism (3); The knee joint wearing mechanism (3) includes a thigh support (31), a calf support (32), and two sets of multi-link hinge mechanisms (33); the configuration of the multi-link hinge mechanism (33) is designed such that the instantaneous relative rotation center between the thigh support (31) and the calf support (32) varies with the flexion and extension angle; the thigh support (31) and the calf support (32) are provided with six connection points for guiding and connecting flexible ropes (21); The control module (4) is used to control the drive module (1).

2. The rope-driven lower limb rehabilitation robot according to claim 1, characterized in that, The multi-link hinge mechanism (33) is a six-bar linkage mechanism; the six-bar linkage mechanism includes a first link (331), a second link (332), a third link (333), a fourth link (334), a fifth link (335), and a sixth link (336) connected sequentially through a revolute joint; wherein, the second link (332) and the fourth link (334) are triangular link assemblies, the first end of the first link (331) is connected to two fixed points on the thigh support (31); the first end of the sixth link (336) is connected to two fixed points on the calf support (32) through a hinge shaft; the second link (331) is connected to the second link (332) and the fourth link (334) through a revolute joint. The first end of the rod (332) is hinged to the second end of the first link (331), and the first end of the fourth link (334) is hinged to the third end of the first link (331); the second end of the second link (332) is hinged to the first end of the third link (333), the second end of the fourth link (334) is hinged to the second end of the third link (333), the third end of the second link (332) is hinged to the first end of the fifth link (335), the second end of the fifth link (335) is hinged to the second end of the sixth link (336), and the third end of the fourth link (334) is hinged to the third end of the sixth link (336).

3. The rope-driven lower limb rehabilitation robot according to claim 2, characterized in that, The lengths of each link and the position of the hinge point of the six-bar linkage are configured such that the relative rotation center trajectory between the thigh support (31) and the lower leg support (32) matches the average trajectory of the instantaneous rotation center when the human knee joint is naturally flexed and extended within a preset angle range.

4. The rope-driven lower limb rehabilitation robot according to claim 1, characterized in that, The thigh support (31) has four connection points: a first connection point (311a) on the anterior side of the proximal end, a second connection point (311b) on the posterior side of the proximal end, a third connection point (311c) on the anterior side of the distal end, and a fourth connection point (311d) on the posterior side of the distal end; at least four of the flexible ropes (21) act independently on the first to fourth connection points (311a, 311b, 311c, 311d) to provide multi-directional suspension and control of the thigh. The lower leg support (32) has two connection points, namely the fifth connection point (311a) on the proximal front side and the sixth connection point (311b) on the proximal rear side; at least two of the flexible ropes (21) act on the fifth connection point (321a) and the sixth connection point (321b) respectively to generate knee flexion or knee extension torque in a coordinated manner.

5. The rope-driven lower limb rehabilitation robot according to claim 1, characterized in that, Each drive unit (11) includes a servo motor (111), a ball screw mechanism (112) driven by the servo motor (111), a moving stage (113) connected to the ball screw mechanism (112), a linear guide rail (114) guiding the moving stage (113), and a tension sensor (115) disposed on the moving stage (113); one end of the flexible rope (21) is fixed to the tension sensor (115).

6. The cable-driven lower limb rehabilitation robot according to claim 1, characterized in that, The control module (4) is configured such that the PLC (41) and the motor servo system (42) receive the IMU sensor signal from the knee joint wearing mechanism (3) and the tension signal from the tension sensor (115) of the drive module (1), and perform closed-loop control of the drive module (1) based on the motion sensor signal and the tension signal.

7. The rope-driven lower limb rehabilitation robot according to claim 1, characterized in that, The rope drive module (2) also includes a Bowden cable sleeve (22), and the flexible rope (21) is inserted inside the Bowden cable sleeve (22).

8. The rope-driven lower limb rehabilitation robot according to claim 1, characterized in that, The robot also includes an outer frame (5), which includes a bottom support frame, side columns and a top beam. The components are rigidly connected by corner pieces and fasteners to form a stable cuboid cage frame.

9. The rope-driven lower limb rehabilitation robot according to claim 8, characterized in that, The bottom sides of the outer frame (5) are respectively equipped with drive and control boxes to accommodate drive module (1) and control module (4); the side columns and crossbeams have reserved installation positions for fixing the guide of rope transmission module (2) and the mounting seat of weight reduction device (6) to provide mechanical support and installation benchmark for the whole machine.

10. The rope-driven lower limb rehabilitation robot according to claim 7, characterized in that, Also includes: The outer frame (5) is equipped with a weight-reducing device (6), which includes a suspension strap (61) for wearing on the patient's torso.

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