A multi-degree-of-freedom waist-knee bionic exoskeleton robot system

Abstract

This invention discloses a multi-degree-of-freedom waist-knee bionic exoskeleton robot system, belonging to the field of exoskeleton assistive robots. Based on the biomechanical characteristics of human movement bearing, its multi-degree-of-freedom waist bionic design aims to provide movement assistance to the human body without affecting the natural movement form and wearing comfort, which is beneficial for the early prevention and rehabilitation of lumbar diseases. The included waist exoskeleton connection system can transfer the weight of the upper limbs to the ground through the knee joint via armpit support, thereby reducing the load on the joints and muscles caused by the wearer's own weight. Simultaneously, the introduction of an overrunning clutch, one of the core components, can provide different contact stiffnesses for the lower limbs in the "support phase" and "swinging phase," overcoming the problem of blood circulation problems at the contact points under prolonged fixed binding. Its combination with armpit support improves the exoskeleton's load-bearing capacity and ability to resist dynamic disturbances, thus achieving a comprehensive improvement in the wearability and practicality of the exoskeleton.

Description

Technical Field

[0001] This invention belongs to the field of exoskeleton-assisted robots. Background Technology

[0002] The spine is an important and complex skeletal structure in the human body, and also one of the more vulnerable parts of the skeleton. The lumbar vertebrae, as the main load-bearing structure of the spine, are highly susceptible to damage and degenerative changes under long-term physiological and external loads. Severe cases can lead to functional loss, deformity, and nerve damage, resulting in lumbar diseases. To address the need for prevention and rehabilitation assistance for lumbar diseases, numerous scholars have conducted extensive research on wearable exoskeleton robots that can reduce the burden on the lower back. However, current lumbar exoskeleton robots are mostly "powered," aiming to improve the load-bearing effectiveness of the exoskeleton robot, while neglecting its geometric biomimetic inclusion of the human lumbar flexion movement. This results in significant differences in lumbar trajectory before and after wearing, meaning that the exoskeleton robot interferes with human movement, mechanically altering the body's natural posture. Therefore, the human-machine integration of exoskeleton robots is insufficient (e.g., publications CN111110520B and CN105459145 B), thus reducing their wearing comfort and practicality. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention provides a multi-degree-of-freedom waist-knee bionic exoskeleton robot system, the technical solution of which is as follows:

[0004] A multi-degree-of-freedom waist-knee bionic exoskeleton robot system includes a waist exoskeleton robot worn on the human body, a waist connection system, and a knee exoskeleton robot. The waist exoskeleton robot, the waist connection system, and the knee exoskeleton robot are connected in sequence. The waist exoskeleton robot includes an armpit bracket and an armpit support base fixed to the armpit area of ​​the human body. The armpit bracket transmits the weight of the upper body to the waist exoskeleton robot through the armpit support base, and the waist connection system transmits the force to the ground through the knee exoskeleton robot.

[0005] In this invention, the lumbar exoskeleton robot includes a shoulder arm, a shoulder base, a first rotation axis, an axillary support, a second rotation axis, an axillary support base, and a hip connection structure. The lumbar exoskeleton robot is fixed to the wearer via straps and the hip connection structure. The shoulder arm is mounted on the shoulder base, which is connected to the straps to prevent slippage during operation. The shoulder base and the support base are connected by a locking cap. The axillary support is mounted on the axillary support base via the first rotation axis, which is designed with a stop structure to ensure stability of the axillary support. The axillary support bracket rotates upwards rather than downwards in its sagittal plane. A second rotation axis is mounted on the axillary support base, causing the axillary support bracket to rotate in the horizontal plane. The axillary support base is equipped with the axillary support bracket, which is covered with flexible material to reduce discomfort in human-machine contact. The axillary support bracket is connected to the strap via a strap buckle. The bottom of the axillary support base is connected to the top vertebra, the bottom of the top vertebra is connected to the vertebral element, and the lower end of the vertebral element is connected to the hip connection structure. It includes a drive rope and a spring that connect the vertebral element and the hip connection structure.

[0006] Furthermore, the vertebral element includes four vertebrae connected by universal joints. Each universal joint has three rotational degrees of freedom, corresponding to the degrees of freedom of the lumbar vertebrae.

[0007] In this invention, the waist connection system includes two lumbar support plates (left and right), a waist connection hip joint, a leg rotation axis, a waist belt, a strap buckle, a buffer mechanism, a strap insertion port, and a buffer slot. The waist connection hip joint is connected to the universal joint in the waist exoskeleton robot. Three drive ropes and springs are provided and fixed in the mounting holes provided in the hip joint. The waist belt is used for auxiliary fixation so that the exoskeleton hip joint part is worn in the corresponding position of the human hip joint. The left and right parts of the waist belt are connected by the strap buckle and the strap insertion port. There are two buffer mechanisms, which are respectively connected and fixed to the left and right lumbar support plates in the buffer slot. The buffer slot has fixing grooves on the buffer shell at different positions to adjust the left and right installation positions to meet the needs of users with different body shapes.

[0008] Furthermore, the cushioning mechanism includes a universal ball connector, a central cushioning compression spring, cushioning compression spring I, a cushioning shell, and cushioning compression spring II. The universal ball connector is fixed to the waist support plate and connected to the central cushioning compression spring. During operation, the central rod of the central cushioning compression spring extends backward through the rear cover hole of the cushioning shell, while the central rods of cushioning compression spring I and cushioning compression spring II extend forward. At this time, the three cushioning compression springs in the cushioning shell are in a compressed state, thus providing a cushioning effect.

[0009] In this invention, the knee joint exoskeleton robot includes a nonlinear human-machine contact unit and a clutch drive unit. The nonlinear human-machine contact unit includes a waist fixation component, a thigh adjustment and fixation component, a variable-cell bionic knee joint, a variable stiffness support rod structure, a calf adjustment and support component, and an exoskeleton buffer layer. The waist fixation component is connected to the leg rotation axis of the waist connection system, and the bottom is sequentially connected to the thigh adjustment and fixation component, the exoskeleton buffer layer, the variable-cell bionic knee joint, the variable stiffness support rod structure, and the calf adjustment and support component.

[0010] The clutch drive unit is installed on the exoskeleton buffer layer and includes an overrunning clutch drive unit assembly, springs and damping, and an exoskeleton articulated armor layer. The overrunning clutch drive unit assembly includes a rear end cover and a ratchet mounted on the rear end cover. The ratchet, pulley, and torsion spring are respectively equipped with upper and lower stop posts. The pulley and torsion spring are connected to a spring damping pull rope. The pawl is provided with a permanent magnet at the lower end, which cooperates with the permanent magnet at the upper end of the permanent magnet on the rear end cover.

[0011] Furthermore, the rear cover is also equipped with a limit wheel for limiting the spring damping pull rope.

[0012] Furthermore, the exoskeleton's articulated armor layer contains a close-fitting woven material.

[0013] This invention provides a method for joint movement in the multi-degree-of-freedom waist-knee bionic exoskeleton robot system of this invention, including a support phase and a swing phase.

[0014] Support level:

[0015] ① In the initial stage of the support phase, the stepper motor, which serves as the drive input, starts and causes the ratchet to rotate clockwise. At this time, the lower end of the permanent magnet on the pawl attracts the upper end of the permanent magnet. During the rotation, the spring and damper extend and store energy.

[0016] ② During the continuous support phase, the stepper motor rotates, pulling the spring and damper to retract, thereby pulling the side armor layer and transferring the pulling force from the left to the right. The stepper motor stops after rotating at the rated angle. At this time, the ratchet and pawl mechanism self-lock, and the entire clutch cannot reverse counterclockwise. The linear spring is still in the extended state. The normal load of the tension and relaxation wearable system on the human body is increased by rotating the stepper motor, and the effectiveness of the assist is increased by improving the stiffness of the human-machine contact.

[0017] ③ At the end of the support phase, the stepper motor rotates clockwise by a small angle again and then stops, causing the upper stop column to lift the front end of the pawl and attach to the permanent magnet, thus achieving the effect of releasing the clutch self-locking.

[0018] Swinging phase:

[0019] ① At the beginning of the swing phase, the lower end of the permanent magnet on the pawl remains attracted to the upper end of the permanent magnet. The spring immediately releases energy and retracts, causing the ratchet to rotate counterclockwise. The spring and damping as a whole quickly retract to the right.

[0020] ② During the continuous and final phases of the swing phase, a torsion spring is installed at the connection between the ratchet and the stepper motor to ensure that the ratchet reverses and recovers at a sufficiently large angle. The lower stop rotates to the upper left position of the pawl and pulls the pawl away from the upper end of the permanent magnet, causing it to lock the ratchet. The clutch can only rotate clockwise.

[0021] At this point, one cycle of clutch operation is complete, and the clutch awaits the start of the next support phase.

[0022] The technical effects achieved by this invention are:

[0023] This invention features a multi-degree-of-freedom biomimetic design for the lumbar region based on the biomechanical characteristics of human movement. It aims to provide movement assistance without affecting the natural movement patterns and wearing comfort, thus aiding in the early prevention and rehabilitation of lumbar diseases. The lumbar exoskeleton connection system transfers the weight of the upper limbs to the ground via the knee joint through armpit support, thereby reducing the load on the joints and muscles caused by the wearer's weight. Simultaneously, the introduction of an overrunning clutch, a core component, provides different contact stiffness for the lower limbs in the "support phase" and "swinging phase," overcoming the problem of poor blood circulation at the contact points caused by prolonged use of fixed binding. Combined with armpit support, it enhances the exoskeleton's load-bearing capacity and ability to resist dynamic disturbances, thereby achieving a comprehensive improvement in the wearability and practicality of the exoskeleton. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the multi-degree-of-freedom waist-knee bionic exoskeleton robot system of the present invention.

[0025] Figure 2 For the present invention Figure 1 A schematic diagram of the components of the waist exoskeleton robot.

[0026] Figure 3 For the present invention Figure 2 The working principle diagram of the universal joint in China.

[0027] Figure 4 For the present invention Figure 1 A schematic diagram of the waist connection system.

[0028] Figure 5 For the present invention Figure 4 A schematic diagram of the buffer mechanism in the diagram.

[0029] Figure 6 For the present invention Figure 1 A schematic diagram of the components of the knee joint exoskeleton robot.

[0030] Figure 7 For the present invention Figure 6 Assembly diagram of the overrunning clutch drive unit.

[0031] In the diagram: 1. Human body; 2. Waist exoskeleton robot; 3. Waist connection system; 4. Knee joint exoskeleton robot; 2-1. Shoulder arm; 2-2. Shoulder base; 2-3. First rotation axis; 2-4. Locking cover; 2-5. Straps; 2-6. Strap buckle; 2-7. Axillary support; 2-8. Second rotation axis; 2-9. Axillary support base; 2-10. Cover plate; 2-11. Nut; 2-12. Vertebra; 2-13. Drive rope and spring; 2-14. Universal joint; 2-15. Hip connection structure; 2-16. Top vertebra.

[0032] 3-1 Waist support plate; 3-2 Waist connection to hip joint; 3-3 Leg rotation axis; 3-4 Waist belt; 3-5 Strap buckle; 3-6 Buffer mechanism; 3-7 Strap insertion port; 3-8 Buffer slot.

[0033] 3-6-1 Universal ball connector; 3-6-2 Center buffer compression spring; 3-6-3 Buffer compression spring I; 3-6-4 Buffer housing; 3-6-5 Buffer compression spring II;

[0034] 4-1 Waist fixation component; 4-2 Thigh adjustment and fixation component; 4-3 Overrunning clutch drive unit component; 4-4 Variable-cell bionic knee joint; 4-5 Variable stiffness support rod structure; 4-6 Lower leg adjustment and support component; 4-7 Exoskeleton buffer layer; 4-8 Springs and damping; 4-9 Exoskeleton articulated armor layer; 4-10 Close-fitting woven fabric.

[0035] 4-3-1 Lower stop post; 4-3-2 Pulley and torsion spring; 4-3-3 Ratchet; 4-3-4 Rear end cover; 4-3-5 Upper stop post; 4-3-6 Pawl; 4-3-7 Pawl connecting screw; 4-3-8 Upper end of permanent magnet; 4-3-9 Lower end of permanent magnet; 4-3-10 Stop post positioning screw; 4-3-11 Limiting wheel; 4-3-12 Spring damping pull rope. Detailed Implementation

[0036] This invention discloses a novel multi-degree-of-freedom waist-knee bionic exoskeleton robot, such as... Figure 1As shown, the device includes a waist exoskeleton robot 2, a waist connection system 3, and a knee exoskeleton robot 4, all worn on the human body. The waist exoskeleton robot 2, waist connection system 3, and knee exoskeleton robot 4 are connected sequentially. The waist exoskeleton robot 2 includes an armpit support 2-7 and an armpit support base 2-9 fixed to the armpit area. Its functions are as follows: ① The armpit support 2-7 transmits the weight of the upper body to the waist exoskeleton 2 via the armpit support base 2-9, and the waist connection system 3 transmits the force to the ground via the knee exoskeleton 4, reducing the load on the joints and muscles caused by the wearer's weight; ② It proposes a bionic hip joint 2-15 with a cushioning function and an overrunning clutch device 4-3, combined with a variable-cell bionic knee joint 4-4, to improve the wearability and comfort of the exoskeleton. Its composition and working principle are as follows.

[0037] The composition and working principle of the lumbar exoskeleton robot 2 are as follows: Figure 2 As shown: The lumbar exoskeleton robot 2 includes a shoulder arm 2-1, a shoulder base 2-2, a first rotation axis 2-3, an axillary support 2-7, a second rotation axis 2-8, an axillary support base 2-9, and a hip connection structure 2-15. The lumbar exoskeleton robot is fixed to the wearer via straps 2-5 and the hip connection structure 2-15. The shoulder arm 2-1 is mounted on the shoulder base 2-2. The straps 2-5 connect the shoulder base 2-2 to prevent slippage during operation. The shoulder base 2-2 is connected to the support base via a locking cap 2-4, which can be adjusted according to the wearer's body shape. The axillary support 2-7 is mounted on the axillary support base 2-9 via the first rotation axis 2-3. The first rotation axis 2-3 is designed with a stop structure to ensure that the axillary support 2-7 can rotate upwards rather than downwards in its sagittal plane, thereby ensuring support and improving wearing comfort. The second rotation axis 2-8 is mounted on the armpit support base 2-9, allowing the armpit bracket 2-7 to rotate on the horizontal plane. The armpit bracket 2-7 is mounted on the armpit support base 2-9, and the armpit bracket 2-7 is made of flexible material to effectively reduce discomfort from human-machine contact. Part of the wearer's weight is transferred from the armpit bracket 2-7 to the armpit support base 2-9, and then from the armpit support base 2-9 to the shoulder base 2-2. The force on the shoulder base is then transmitted to the top vertebra 2-16. Based on the distribution of lumbar spine mobility in the human body, the lumbar exoskeleton robot has four vertebrae 2-12, each corresponding to a human lumbar vertebra. The vertebral components are connected by universal joints 2-14, such as... Figure 3As shown. Each universal joint has 3 rotational degrees of freedom, corresponding to the lumbar spine's degrees of freedom. Therefore, the exoskeleton robot proposed in this patent has biomimetic inclusiveness in its lumbar movement space. When the exoskeleton is in an upright load-bearing condition, the multi-degree-of-freedom biomimetic lumbar exoskeleton, under the action of the drive rope 2-13, tensions its internal buckles to lock it in the sagittal plane of the human body, pressing the four vertebral components together to obtain a certain bending modulus and achieve the purpose of load bearing. The load of the upper body is transferred from the exoskeleton to the hip connection structure 2-15 through the armpit support 2-7. When the wearer performs a bending motion, the drive rope 2-13 relaxes, the multi-degree-of-freedom biomimetic lumbar exoskeleton's 5 degrees of freedom unlocks, and the load of the human waist is transferred to the hip connection structure 2-15. This realizes the entire process of the human body's weight being borne by the armpit and then transferred to the hip connection structure on the exoskeleton, reducing the load on the wearer's waist and back muscles and joints.

[0038] The waist connection system of the novel exoskeleton robot of this invention is as follows: Figure 4 As shown, the working principles of the waist connection mechanism and the buffer mechanism of this system are also detailed in the appendix. Figures 4-5 The lumbar support system 3 includes two lumbar support plates 3-1 (left and right), a lumbar hip joint 3-2, a leg rotation axis 3-3, a waist belt 3-4, a strap buckle 3-5, a cushioning mechanism 3-6, a strap insertion port 3-7, and a shock absorber slot 3-8. The lumbar hip joint 3-2 is connected to the universal joint 2-14 in the lumbar exoskeleton robot 2. Three drive ropes and springs 2-13 are provided and fixed in the mounting holes of the hip joint, and are further secured by the waist belt 3-4, so that the exoskeleton hip joint part is worn in the corresponding position of the human hip joint. The left and right parts of the waist belt 3-4 are connected by the strap buckle 3-5 and the strap insertion port 3-7. After wearing, the human body compresses the lumbar support plate 3-1 backward during movement, causing it to move backward. The cushioning mechanism 3-6 includes a universal ball connector 3-6-1, a central cushioning compression spring 3-6-2, a cushioning compression spring I 3-6-3, a cushioning shell 3-6-4, and a cushioning compression spring II 3-6-5. The universal ball connector 3-6-1 is fixed to the lumbar support plate 3-1 and connected to the central cushioning compression spring 3-6-2. During operation, the central rod of the central cushioning compression spring 3-6-2 extends backward through the rear cover hole of the cushioning shell 3-6-4, while the central rods of the cushioning compression springs I 3-6-3 and II 3-6-5 extend forward. At this time, the three cushioning compression springs in the cushioning shell 3-6-4 are compressed, providing a cushioning effect. There are two cushioning mechanisms 3-6, which are respectively connected and fixed to the left and right lumbar support plates 3-1 in the buffer slots 3-8. The buffer slots 3-8 have fixing grooves on the cushioning shell 3-6-4 at different positions, allowing adjustment of the left and right installation positions to meet the needs of users with different body shapes.

[0039] The knee joint exoskeleton system of the novel exoskeleton robot of this invention is as follows: Figure 6 As shown. The knee joint exoskeleton robot 4 of the present invention includes a nonlinear human-machine contact unit and a clutch drive unit. The nonlinear human-machine contact unit includes a waist fixation component 4-1, a thigh adjustment and fixation component 4-2, a variable-cell bionic knee joint 4-4, a variable stiffness support rod structure 4-5, a calf adjustment and support component 4-6, and an exoskeleton buffer layer 4-7. The waist fixation component 4-1 is connected to the leg rotation axis 3-3 of the waist connection system 3. The bottom is sequentially connected to the thigh adjustment and fixation component 4-2, the exoskeleton buffer layer 4-7, the variable-cell bionic knee joint 4-4, the variable stiffness support rod structure 4-5, and the calf adjustment and support component 4-6. The exoskeleton hinged armor layer 4-7 is provided with a close-fitting woven material 4-10 to increase softness and reduce injury to the human body.

[0040] The gait cycle is divided into a swing phase and a support phase. In the swing phase, the assistive device should focus on the flexibility of the entire tension-relaxation wear system during the assistive process. In the support phase, increasing the human-machine contact stiffness is beneficial to improving the assistive effect. Therefore, when the human-machine parallel tension-relaxation wear device completes this process, more attention should be paid to the study of the dynamic characteristics of the device's load-bearing contact stiffness system relative to the human body. The system can be divided into two parts: (1) a nonlinear human-machine contact unit (hereinafter referred to as the nonlinear human-machine contact unit) that includes the mechanical parameters of muscle tissue and the contact parameters of the buffer layer-armor layer. (2) a motor-overrunning clutch drive unit (hereinafter referred to as the clutch drive unit).

[0041] See appendix Figure 7 The clutch drive unit of the present invention is installed on the exoskeleton buffer layer 4-7, including an overrunning clutch drive unit assembly 4-3, a spring and damping 4-8, and an exoskeleton articulated armor layer 4-9. The overrunning clutch drive unit assembly 4-3 includes a rear end cover 4-3-4, a ratchet 4-3-3 installed on the rear end cover 4-3-4, and a pawl 4-3-6 that cooperates with the ratchet 4-3-3. The ratchet 4-3-3 is provided with a pulley and a torsion spring 4-3-2. The pulley and torsion spring 4-3-2 are respectively equipped with an upper stop post 4-3-5 and a lower stop post 4-3-1 at their upper and lower positions. The pulley and torsion spring 4-3-2 are connected to a spring damping rope 4-3-12. The spring damping rope 4-3-12 is connected to the spring and damping 4-8. The pawl 4-3-6 is provided with a lower end 4-3-9 of a permanent magnet, which cooperates with the upper end 4-3-8 of the permanent magnet provided on the rear end cover 4-3-4. The rear cover 4-3-4 is also equipped with a limiting wheel 4-3-11 for limiting the spring damping rope 4-3-12.

[0042] The working principle of the knee exoskeleton wearable system is as follows: Figure 6As shown: ① Support Phase: The overrunning clutch drive unit assembly 4-3 releases its self-lock, causing the spring and damper 4-8 to retract, thereby pulling the exoskeleton hinged armor layer 4-9 and transferring the pulling force from the left to the right. When the displacement provided by the motor reaches the preset value, the motor self-locks, increasing the pressure of the exoskeleton on the human body and improving the effectiveness of the assist by increasing the stiffness of the human-machine contact; ② Swing Phase: The overrunning clutch drive unit assembly 4-3 releases its self-lock, and the spring, due to the rapid release of energy accumulated in the support phase, causes the spring and damper 4-8 to quickly retract to the right. After this process, the motor self-locks again, waiting for the arrival of the next support phase. This setting can reduce the pressure of the exoskeleton on the human body, increase the dexterity of lower limb movement, and improve wearing comfort.

[0043] The prototype and mechanism of the overrunning clutch drive unit of this invention are as follows: Figure 7 As shown.

[0044] (1) Supporting phase:

[0045] ① In the initial stage of the support phase, the stepper motor, which serves as the drive input, starts and causes the ratchet 4-3-3 to rotate clockwise. At this time, the lower end 4-3-8 of the permanent magnet on the pawl 4-3-6 is attracted to the upper end 4-3-9 of the permanent magnet. During the rotation, the spring and damper 4-8 extend and store energy.

[0046] ② During the sustained support phase, the stepper motor rotates, causing the spring and damper 4-8 to retract, which in turn pulls the side armor layer 4-9 and transfers the pulling force from the left to the right. The stepper motor stops after rotating to the rated angle. At this time, the ratchet 4-3-3 and pawl 4-3-6 mechanism self-lock, and the entire clutch cannot rotate counterclockwise. The linear spring remains in an extended state. During this phase, the rotation of the stepper motor increases the normal load of the tension-relaxation wearable system on the human body, thereby increasing the effectiveness of the assist by improving the human-machine contact stiffness.

[0047] ③ At the end of the support phase, the stepper motor rotates clockwise by a small angle again and then stops, causing the upper stop post 4-3-5 to lift the front end of the pawl 4-3-6 and attach it to the permanent magnet, thus achieving the effect of releasing the clutch self-lock.

[0048] (2) Oscillating phase:

[0049] ① At the beginning of the swing phase, due to the release of the self-locking mechanism in the previous phase, the lower end 4-3-9 of the permanent magnet on the pawl 4-3-6 remains attracted to the upper end 4-3-8 of the permanent magnet. The spring immediately releases energy and retracts, causing the ratchet 4-3-3 to rotate counterclockwise. The spring and damper 4-8 retract rapidly to the right as a whole.

[0050] ② During the continuous and final phases of the oscillation phase, due to the external torsion spring 4-3-2 at the connection between ratchet 4-3-3 and the stepper motor, the reverse return angle of ratchet 4-3-3 is sufficiently large. The lower stop 4-3-1 rotates to the upper left position of pawl 4-3-6 and pulls the pawl away from the upper end 4-3-8 of the permanent magnet, causing it to lock ratchet 4-3-3. The clutch can only rotate clockwise. At this point, one cycle of clutch operation ends, awaiting the start of the next support phase.

[0051] The advantages of this design are: it can minimize the pressure on the human body during the swing phase, increasing the comfort and flexibility of wearing the exoskeleton; throughout the entire gait cycle, only a unidirectional drive stepper motor is needed to control the overrunning clutch; and it can select self-locking (preventing spring return) and self-locking release without an additional power source under non-drive conditions.

Claims

1. A multi-degree-of-freedom waist-knee bionic exoskeleton robot system, characterized in that: The system includes a waist exoskeleton robot (2) worn on the human body, a waist connection system (3), and a knee exoskeleton robot (4). The waist exoskeleton robot (2), the waist connection system (3), and the knee exoskeleton robot (4) are connected in sequence. The waist exoskeleton robot (2) includes an armpit support (2-7) and an armpit support base (2-9) fixed in the armpit area of ​​the human body. The armpit support (2-7) transmits the weight of the upper body to the waist exoskeleton robot (2) through the armpit support base (2-9), and the waist connection system (3) transmits the force to the ground through the knee exoskeleton robot (4). The lumbar exoskeleton robot (2) includes a shoulder arm (2-1), a shoulder base (2-2), a first rotation axis (2-3), an axillary support (2-7), a second rotation axis (2-8), an axillary support base (2-9), and a hip connection structure (2-15). The lumbar exoskeleton robot (2) is fixed to the wearer via straps (2-5) and the hip connection structure (2-15). The shoulder arm (2-1) is mounted on the shoulder base (2-2), and the shoulder base (2-2) is connected to the straps (2-5) to prevent slippage during operation. The shoulder base (2-2) is connected to the support base via a locking cap (2-4). The axillary support (2-7) is mounted on the axillary support base (2-9) via the first rotation axis (2-3). The first rotation axis (2-3) is designed with a stop. The structure is designed to ensure that the axillary support (2-7) rotates upward rather than downward in its sagittal plane. A second rotation axis (2-8) is installed on the axillary support base (2-9), which allows the axillary support (2-7) to rotate in the horizontal plane. The axillary support (2-7) is mounted on the axillary support base (2-9), and the axillary support (2-7) is covered with flexible material to reduce discomfort in human-machine contact. The axillary support (2-7) is connected to the strap (2-5) via a strap buckle (2-6). The bottom of the axillary support base (2-9) is connected to the top vertebra (2-16), the bottom of the top vertebra (2-16) is connected to the vertebral element, and the lower end of the vertebral element is connected to the hip connection structure (2-15). The structure includes a drive rope and a spring (2-13) that connects the vertebral element and the hip connection structure (2-15). The waist connection system (3) includes two lumbar support plates (3-1), a waist connection hip joint (3-2), a leg rotation axis (3-3), a waist belt (3-4), a strap buckle (3-5), a buffer mechanism (3-6), a strap insertion port (3-7), and a buffer slot (3-8). The waist connection hip joint (3-2) is connected to the universal joint (2-14) in the waist exoskeleton robot (2). Three drive ropes and springs (2-13) are provided and fixed in the mounting holes provided in the hip joint, and the waist belt (3-4) is used to connect the hip joint (3-14). 3-4) Assisted fixation, so that the hip joint part of the exoskeleton is worn in the corresponding position of the human hip joint. The left and right parts of the waist belt (3-4) are connected by the outer buckle (3-5) and the strap insertion (3-7). There are two cushioning mechanisms (3-6), which are connected and fixed to the left and right waist protection plates (3-1) on the buffer slots (3-8). The buffer slots (3-8) are provided with fixing grooves on the buffer shells (3-6-4) in different positions to adjust the left and right installation positions to meet the needs of users with different body shapes. The knee joint exoskeleton robot (4) includes a nonlinear human-machine contact unit and a clutch drive unit. The nonlinear human-machine contact unit includes a waist fixation component (4-1), a thigh adjustment fixation component (4-2), a variable-cell bionic knee joint (4-4), a variable stiffness support rod structure (4-5), a lower leg adjustment support component (4-6), and an exoskeleton buffer layer (4-7). The waist fixation component (4-1) is connected to the leg rotation axis (3-3) of the waist connection system (3). The bottom is connected in sequence to the thigh adjustment fixation component (4-2), the exoskeleton buffer layer (4-7), the variable-cell bionic knee joint (4-4), the variable stiffness support rod structure (4-5), and the lower leg adjustment support component (4-6). The clutch drive unit is mounted on the exoskeleton buffer layer (4-7) and includes an overrunning clutch drive unit assembly (4-3), a spring and damper (4-8), and an exoskeleton articulated armor layer (4-9). The overrunning clutch drive unit assembly (4-3) includes a rear end cover (4-3-4), a ratchet (4-3-3) mounted on the rear end cover (4-3-4), and a pawl (4-3-6) cooperating with the ratchet (4-3-3). The ratchet (4-3-3) is externally equipped with a pulley and... The torsion spring (4-3-2), pulley and torsion spring (4-3-2) are respectively equipped with upper stop column (4-3-5) and lower stop column (4-3-1) at the upper and lower positions. The pulley and torsion spring (4-3-2) are connected to spring damping rope (4-3-12). Spring damping rope (4-3-12) is connected to spring and damping (4-8). The pawl (4-3-6) is provided with the lower end (4-3-9) of permanent magnet, which cooperates with the upper end (4-3-8) of permanent magnet set on the rear end cover (4-3-4).

2. The multi-degree-of-freedom waist-knee bionic exoskeleton robot system according to claim 1, characterized in that: The vertebral element includes four vertebrae (2-12), which are connected by universal joints (2-14). Each universal joint has three rotational degrees of freedom, corresponding to the degrees of freedom of the lumbar vertebrae.

3. The multi-degree-of-freedom waist-knee bionic exoskeleton robot system according to claim 1, characterized in that: The buffer mechanism (3-6) includes a universal ball connector (3-6-1), a central buffer compression spring (3-6-2), a buffer compression spring I (3-6-3), a buffer shell (3-6-4), and a buffer compression spring II (3-6-5). The universal ball connector (3-6-1) is fixed on the waist support plate (3-1) and connected to the central buffer compression spring (3-6-2). When working, the central rod of the central buffer compression spring (3-6-2) extends backward through the rear cover hole of the buffer shell (3-6-4), and the central rods of the buffer compression spring I (3-6-3) and the buffer compression spring II (3-6-5) extend forward. At this time, the three buffer compression springs in the buffer shell (3-6-4) are in a compressed state, which plays a buffering role.

4. The multi-degree-of-freedom waist-knee bionic exoskeleton robot system according to claim 1, characterized in that: The rear end cover (4-3-4) is also equipped with a limit wheel (4-3-11) for limiting the spring damping rope (4-3-12).

5. The multi-degree-of-freedom waist-knee bionic exoskeleton robot system according to claim 1, characterized in that: The exoskeleton articulated armor layer (4-9) contains a close-fitting woven fabric (4-10).

6. A method for knee joint movement in a multi-degree-of-freedom waist-knee bionic exoskeleton robot system according to any one of claims 1-5, characterized in that: Including the support phase and the oscillation phase, Support level: In the initial stage of the support phase, the stepper motor, which serves as the drive input, is started, causing the ratchet (4-3-3) to rotate clockwise. At this time, the lower end (4-3-9) of the permanent magnet on the pawl (4-3-6) is attracted to the upper end (4-3-8) of the permanent magnet. During the rotation, the spring and damper (4-8) extend and store energy. ② During the continuous support phase, the stepper motor rotates, pulling the spring and damper (4-8) to retract, thereby pulling the exoskeleton hinged armor layer (4-9) and transmitting the pulling force from the left to the right. The stepper motor stops after rotating the rated angle. At this time, the ratchet (4-3-3) and pawl (4-3-6) mechanism self-locks, and the entire clutch cannot reverse counterclockwise. The linear spring is still in the extended state. The normal load of the tension and relaxation wearable system on the human body is increased by rotating the stepper motor, and the effectiveness of the assist is increased by improving the stiffness of the human-machine contact. ③ At the end of the support phase, the stepper motor rotates clockwise by a small angle again and then stops, causing the upper stop column (4-3-5) to lift the front end of the pawl (4-3-6) and attach to the permanent magnet, thereby releasing the self-locking effect of the clutch. Swinging phase: At the beginning of the swing phase, the lower end (4-3-9) of the permanent magnet on the pawl (4-3-6) remains attracted to the upper end (4-3-8) of the permanent magnet. The spring immediately releases energy and retracts, causing the ratchet (4-3-3) to rotate counterclockwise. The spring and damper (4-8) as a whole quickly retract to the right. ② During the continuous and final phases of the swing phase, a torsion spring (4-3-2) is installed at the connection between the ratchet (4-3-3) and the stepper motor, so that the ratchet (4-3-3) has a sufficiently large reverse return angle. The lower stop (4-3-1) rotates to the upper left position of the pawl (4-3-6) and moves the pawl away from the upper end of the permanent magnet (4-3-8), so that it locks the ratchet (4-3-3), and the clutch can only rotate clockwise. At this point, one cycle of clutch operation is complete, and the clutch awaits the start of the next support phase.

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