Modular knee joint exoskeleton based on series elastic drivers

Abstract

A modular knee joint exoskeleton based on a series elastic driver comprises the series elastic driver, the modular knee joint exoskeleton, a Bowden cable and a main control module, the series elastic driver is connected with the modular knee joint exoskeleton through the Bowden cable, and an elastic unit is arranged in the modular knee joint exoskeleton; the elastic unit is used for buffering and compression energy storage in the knee joint buckling process, and the main control module is used for controlling the series elastic driver to work and driving the elastic unit to rebound to generate assistance. According to the modular knee joint exoskeleton system based on the series elastic driver, the modular knee joint exoskeleton is separated from the series elastic driver in the process of knee joint buckling in the gait cycle of a wearer, and only an elastic unit in the modular knee joint exoskeleton provides buffering; the series elastic drivers do not generate extra resistance to the wearer.

Description

Technical Field

[0001] The invention belongs to the field of rehabilitation medical equipment, and in particular relates to a modular knee joint exoskeleton based on a series elastic driver. Background Art

[0002] The existing knee joint powered exoskeleton is a type of wearable mechanical device that assists the wearer to complete knee joint movement based on the human limb movement relationship and physiological structure. During use, the powered knee joint exoskeleton fits closely to the human body, and the output torque of the motor is transmitted to the lower limb knee joint through the motor shaft, reducer, and exoskeleton hardware, thereby driving the rotation of the knee joint. As a wearable device, the knee joint powered exoskeleton has a direct physical coupling with the human body, so safety and comfort are crucial. At present, most of the knee joint powered exoskeletons adopt the direct motor drive mode, which has the problems of poor safety and low comfort. Due to the direct physical contact between the human body and the exoskeleton, the lack of elastic drive mode and mechanical structure will reduce the wearing comfort of the equipment, and even cause personal injury accidents. At the same time, the existing knee joint powered exoskeletons have the disadvantages of being too large and bulky, the actuator is not user-friendly, and the equipment has no elastic space margin to cooperate with the user after sudden power on or power off. Secondly, the existing knee joint exoskeletons mostly adopt the control strategy of motor forward and reverse rotation to avoid the wearer from resisting the motor damping, and the power separation cannot be well achieved in the series elastic drive, which makes the knee joint exoskeleton using series elastic drive mostly use two sets of drive lines, making the structure complex and increasing power consumption. These shortcomings constitute the main reason hindering the widespread application of knee joint powered exoskeletons. Summary of the invention

[0003] The object of the present invention is to provide a modular knee exoskeleton based on a series elastic actuator to solve the above problems.

[0004] To achieve the above object, the present invention adopts the following technical solutions: A modular knee exoskeleton based on a series elastic driver comprises a series elastic driver, a modular knee exoskeleton, a Bowden cable and a main control module. The series elastic driver is connected to the modular knee exoskeleton via the Bowden cable. An elastic unit is arranged in the modular knee exoskeleton. The elastic unit is used for buffering and compressing energy storage during the flexion process of the knee joint. The main control module is used for controlling the operation of the series elastic driver to drive the elastic unit to rebound and generate assistance.

[0005] Furthermore, the series elastic driver includes a brushless DC motor, a first reduction gear, a second reduction gear, a first end face ratchet, a second end face ratchet, a capstan, a steering gear, a steering gear housing, a steering gear, a first housing and a second housing, wherein a motor mounting boss and a steering gear mounting groove are provided in the first housing, the brushless DC motor is installed in the motor mounting boss and fixed by bolts, the output end of the brushless DC motor and the motor output shaft are connected by bolts, and the first reduction gear is connected to the motor output shaft by a flat key; the steering gear is installed in the steering gear mounting groove, the steering gear housing is covered, and the steering gear housing is fixed by bolts; the steering gear gear is fixed to the steering gear by bolt connection; a Bowden wire tube mounting seat is provided at the bottom of the first housing; The second housing is provided with a boss for supporting the first reduction gear; the second housing is provided with a first bearing seat for placing the first tapered roller bearing, one end of the gear shaft is placed in the bearing hole of the first tapered roller bearing, and the other end is connected to the second reduction gear through a flat key; The first end face ratchet is fixed to the first end face ratchet mounting hole on the second reduction gear by means of bolts, and the second end face ratchet is fixed to the second end face ratchet mounting hole on the capstan by means of bolts; A second bearing seat is provided on the first housing for placing a second tapered roller bearing. One end of the capstan shaft is placed in the bearing hole of the second tapered roller bearing, and the other end is connected to the capstan through a flat key. A compression spring is provided between the capstan and the shaft shoulder of the capstan shaft.

[0006] Furthermore, a steering gear push rod is provided on the steering gear, and the capstan is connected to the capstan push rod, the capstan push rod comprises a first pin mounting hole, a second pin mounting hole, a third pin mounting hole, and a fourth pin mounting groove, wherein the first pin mounting hole and the second pin mounting hole form a line contact with the push rod groove on the capstan through the mounting pin, a push rod mounting boss is provided on the first outer shell, a boss pin hole is provided on the push rod mounting boss, the third pin mounting hole is connected to the boss pin hole through a pin, pin mounting hole I, pin mounting hole II, and pin mounting hole III are provided on the steering gear push rod, pin mounting hole I and pin mounting hole II on the steering gear push rod are connected to the fourth pin mounting groove on the capstan push rod through a pin, pin mounting hole III on the steering gear push rod is connected to the rack pin hole on the rack through a pin, the rack is placed in the rack groove on the steering gear outer shell, and meshes with the steering gear on the steering gear output shaft, and the bottom of the rack coincides with the bottom of the steering gear push rod.

[0007] Furthermore, the Bowden cable is arranged in a Bowden cable tube, one end of which is fixed in a Bowden cable tube mounting seat and fixed by a first cable tube fixing nut and a second cable tube fixing nut; one end of the Bowden cable is wound around the capstan, passes through the Bowden cable tube, and the other end is connected to the elastic unit.

[0008] Furthermore, the first shell and the second shell are connected by bolts, and countersunk holes are reserved on the shells for embedding nuts and bolt heads; countersunk holes are reserved on the side of the first shell for embedding nuts when the servo shell is fixed to the first shell by bolts.

[0009] Furthermore, the modular knee exoskeleton includes a femoral fixation module, a tibial fixation module, a knee joint module, an elastic unit, a femoral module IMU, a tibial module IMU, an ankle joint module, a plantar module, an upper drive block housing and a lower drive block housing, the upper end of the knee joint module is connected to the upper drive block housing, the upper drive block housing is connected to the femoral fixation module through a buckle, and the elastic unit is arranged inside the upper drive block housing; the lower end of the knee joint module is connected to the lower drive block housing, the lower drive block housing is connected to the tibial fixation module through a buckle, the lower drive block housing is connected to the ankle joint module, and the ankle joint module is connected to the plantar module through a hinge; the femoral module IMU and the tibial module IMU are respectively arranged on the femoral fixation module and the tibial fixation module, for sending data to the main control module.

[0010] Furthermore, the knee joint module includes an upper driving block, a lower driving block, an outer fixing shell, an inner fixing shell, an outer connecting rod, and an inner connecting rod; one end of the outer connecting rod and the inner connecting rod are connected to the upper driving block, and the other end is connected to the lower driving block, the outer fixing shell and the inner fixing shell are threadedly connected to fix the outer connecting rod, the inner connecting rod, the upper driving block and the lower driving block inside, the outer connecting rod and the inner connecting rod are connected by a sleeve, the upper driving block is fixed to the side of the upper driving block shell by screws, and the lower driving block is fixed to the side of the lower driving block shell by screws.

[0011] Furthermore, the elastic unit is arranged inside the upper driving block shell, and the bottom is installed on the elastic unit base of the upper driving block, the piston rod is connected to the piston rod connecting block, and a Bowden wire ring and a driving wire ring are respectively provided on both sides of the through hole of the piston rod connecting block. One end of the Bowden wire is fixed on the Bowden wire ring, one end of the driving wire is fixed on the driving wire ring, passes through the groove on the upper driving block and the wire channel inside the lower driving block, and the other end is fixed in the groove of the lower driving block; when the knee joint module bends, the driving wire is tensioned and drives the elastic unit to compress, and when the knee joint module is straightened, the driving wire returns to its original state and the elastic unit recovers.

[0012] Furthermore, the femoral fixation module is fixed to the femur by a strap, and the tibial fixation module is fixed to the tibia by a strap.

[0013] Furthermore, the Bowden cable ring passes through the through hole on the piston rod connecting block, and the bottom of the Bowden cable ring has an external thread, and the driving wire ring has an internal thread, and the two are connected together through threads.

[0014] Compared with the prior art, the present invention has the following technical effects: The present invention proposes a modular knee exoskeleton system based on a series elastic driver. During the flexion of the knee joint in the wearer's gait cycle, the modular knee exoskeleton is separated from the series elastic driver, and only the elastic unit in the modular knee exoskeleton provides buffering, and the series elastic driver does not generate additional resistance to the wearer. During the extension of the knee joint in the wearer's gait cycle, the modular knee exoskeleton is connected to the series elastic driver, and the DC brushless motor in the series elastic driver actively drives the elastic unit in the modular knee exoskeleton to rebound, providing walking assistance for the wearer. The modular knee exoskeleton system can be quickly donned and disassembled, reducing the donning and disassembly time, simplifying the overall structure, and reducing the weight of the exoskeleton system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The overall diagram of the modular knee exoskeleton system based on series elastic actuator.

[0016] Figure 2 This is the plane exploded view of the series elastic actuator.

[0017] Figure 3 This is the exploded view of the first axis side of the series elastic actuator.

[0018] Figure 4 This is the exploded view of the second axis side of the series elastic actuator.

[0019] Figure 5 This is a schematic diagram of the location of the Bowden cable tube mounting seat.

[0020] Figure 6 Schematic diagram of the series elastic actuator.

[0021] Figure 7 This is a schematic diagram of the elastic unit installation.

[0022] Figure 8 This is the structural diagram of the winch push rod.

[0023] Fig. 9 This is the structural diagram of the servo push rod.

[0024] Fig.10 It is a modular knee exoskeleton system.

[0025] Fig.11 Exploded view of the knee module.

[0026] in: 1. Series elastic actuator; 2. Modular knee exoskeleton; 3. Bowden cable tube; 4. Bowden cable; 5. Main control module; 6. DC brushless motor; 71. First reduction gear; 72. Second reduction gear; 81. First end face ratchet; 82. Second end face ratchet; 9. Capstan; 10. Capstan push rod; 11. Servo push rod; 12. Rack; 13. Servo gear; 14. Servo housing; 15. Servo; 16. First housing; 17. Second housing; 18. Bone fixation module; 19, tibia fixation module; 201, upper drive block; 202, lower drive block; 21, knee joint module; 22, drive wire; 23, elastic unit; 24, femoral module IMU; 25, tibia module IMU; 26, ankle joint module; 27, plantar module; 28, mounting boss; 29, servo mounting slot; 30, Bowden wire tube mounting seat; 311, first wire tube fixing nut; 312, second wire tube fixing nut; 32, motor output shaft; 33. boss; 34. first bearing seat; 35. first tapered roller bearing; 36. gear shaft; 37. first end face ratchet mounting hole; 38. second end face ratchet mounting hole; 39. second bearing seat; 40. second tapered roller bearing; 41. capstan shaft; 42. compression spring; 431. fourth pin mounting hole; 432. second pin mounting hole; 433. third pin mounting hole; 434. third pin mounting hole; 44. push rod notch; 45. push rod mounting boss; 46. ​​Boss pin hole; 471. Pin mounting hole I; 472. Pin mounting hole II; 473. Pin mounting hole III; 48. Rack pin hole; 49. Rack groove; 501. Outer fixed shell; 502. Inner fixed shell; 511. Outer connecting rod; 512. Inner connecting rod; 52. Sleeve; 53. Upper drive block housing; 54. Lower drive block housing; 55. Elastic unit base; 56. Piston rod connecting block; 57. Bowden wire coupling ring; 58. Drive wire coupling ring. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] A modular knee joint exoskeleton system based on a series elastic driver comprises a series elastic driver 1, a modular knee joint exoskeleton 2, a Bowden cable tube 3, a Bowden cable 4, and a main control module 5; The series elastic driver 1 includes a brushless DC motor 6, a first reduction gear 71, a second reduction gear 72, a first end face ratchet 81, a second end face ratchet 82, a capstan 9, a capstan push rod 10, a steering gear push rod 11, a rack 12, a steering gear gear 13, a steering gear housing 14, a steering gear 15, a first housing 16, and a second housing 17; The modular knee joint exoskeleton 2 includes a femoral fixation module 18, a tibial fixation module 19, an upper driving block 201, a lower driving block 202, a knee joint module 21, a driving wire 22, an elastic unit 23, a femoral module IMU 24, a tibial module IMU 25, an ankle joint module 26, and a sole module 27; One end of the Bowden cable tube 3 is fixed to the first housing 16, and the other end is fixed to the upper drive block housing 53; One end of the Bowden cable 4 is wound around the capstan 9 and passes through the Bowden cable tube 3 , and the other end is connected to the elastic unit 23 .

[0031] The brushless DC motor 6 is mounted in the motor mounting boss 28 of the first housing 16 and fixed by bolts; The steering gear 15 is installed in the steering gear installation slot 29 of the first housing 16, and the steering gear housing 14 is covered and fixed by bolts; The steering gear 13 is fixed to the steering gear 15 by bolt connection; A Bowden cable tube mounting seat 30 is provided at the bottom of the first housing 16 , and one end of the Bowden cable tube 3 is fixed in the Bowden cable tube mounting seat 30 and fixed by a first cable tube fixing nut 311 and a second cable tube fixing nut 312 .

[0032] The output end of the brushless DC motor 6 and the motor output shaft 32 are connected by bolts; The first reduction gear 71 is connected to the motor output shaft 32 via a flat key; The second housing 17 is provided with a boss 33 for abutting against the first reduction gear 71 to prevent the first reduction gear 71 from axial movement; The second housing 17 is provided with a first bearing seat 34 for placing a first tapered roller bearing 35. One end of the gear shaft 36 is placed in the bearing hole of the first tapered roller bearing 35, and the other end is connected to the second reduction gear 72 through a flat key. The first end face ratchet 81 is fixed to the first end face ratchet mounting hole 37 on the second reduction gear 72 by bolts, and the second end face ratchet 82 is fixed to the second end face ratchet mounting hole 38 on the capstan 9 by bolts; The first housing 16 is provided with a second bearing seat 39 for placing a second tapered roller bearing 40. One end of the capstan shaft 41 is placed in the bearing hole of the second tapered roller bearing 40, and the other end is connected to the capstan 9 through a flat key. A compression spring 42 is provided between the capstan 9 and the shoulder of the capstan shaft 41 .

[0033] The winch push rod 10 comprises a first pin mounting hole 431, a second pin mounting hole 432, a third pin mounting hole 433, and a fourth pin mounting slot 434, wherein the first pin mounting hole 431 and the second pin mounting hole 432 form a line contact with the push rod slot 44 on the winch 9 through the mounting pins. A push rod mounting boss 45 is provided on the first housing 16, and a boss pin hole 46 is provided on the push rod mounting boss 45. The third pin mounting hole 433 is connected to the boss pin hole 46 through a pin. The steering gear push rod 11 is provided with a pin mounting hole I 471, a pin mounting hole II 472, and a pin mounting hole III 473. The pin mounting hole I 471 and the pin mounting hole II 472 on the steering gear push rod 11 are connected to the fourth pin mounting groove 434 on the capstan push rod 10 through a pin. The pin mounting hole III 473 on the steering gear push rod 11 is connected to the rack pin hole 48 on the rack 12 through a pin. The rack 12 is placed in the rack groove 49 on the steering gear housing 14 and meshes with the steering gear 13 on the output shaft of the steering gear 15. The bottom of the rack 12 coincides with the bottom of the steering gear push rod 11.

[0034] The first housing 16 and the second housing 17 are connected by bolts, and countersunk holes are reserved on the housings for embedding nuts and bolt heads; A countersunk hole is reserved on the side of the first housing 16 for embedding nuts when the steering gear housing 14 is fixed to the first housing 16 by bolts.

[0035] The knee joint module 21 includes an outer fixing shell 501, an inner fixing shell 502, an outer connecting rod 511, and an inner connecting rod 512; one end of the outer connecting rod 511 and the inner connecting rod 512 are connected to the upper driving block 201, and the other end is connected to the lower driving block 202, the outer fixing shell 501 and the inner fixing shell 502 are threadedly connected to fix the outer connecting rod 511, the inner connecting rod 512, the upper driving block 201 and the lower driving block 202 inside, the outer connecting rod 511 and the inner connecting rod 512 are connected by a sleeve 52, the upper driving block 201 is fixed to the side of the upper driving block shell 53 by screws, and the lower driving block 202 is fixed to the side of the lower driving block shell 54 by screws; The elastic unit 23 is arranged inside the upper driving block housing 53, and the bottom is installed on the elastic unit base 55 of the upper driving block 201. The piston rod is connected to the piston rod connecting block 56. The two sides of the through hole of the piston rod connecting block 56 are respectively provided with a Bowden wire ring 57 and a driving wire ring 58. One end of the Bowden wire 4 is fixed to the Bowden wire ring 57, and one end of the driving wire 22 is fixed to the driving wire ring 58, passing through the groove on the upper driving block 201 and the wire channel inside the lower driving block 202, and the other end is fixed in the groove of the lower driving block 202; when the knee joint module 21 is bent, the driving wire 22 is tightened and drives the elastic unit 23 to compress, and when the knee joint module 21 is straightened, the driving wire 22 returns to its original state and the elastic unit 23 recovers; the femoral fixation module 18 is fixed to the femur by a strap, and the tibial fixation module 19 is fixed to the tibia by a strap; The ankle joint module 26 is connected to the sole module 27 via a hinge; The femoral fixation module 18 is fixed to the femur by a strap, the tibial fixation module 19 is fixed to the tibia and ankle joint by a strap, the upper drive block housing 53 is connected to the femoral fixation module 18 by a buckle, and the lower drive block housing 54 is connected to the tibial fixation module 19 by a buckle; The plantar module 27 is connected to the tibia fixing module 19 via a hinge.

[0036] The Bowden wire ring 57 passes through the through hole on the piston rod connecting block 56, and has an external thread at the bottom. The driving wire ring 58 has an internal thread, and the two are connected together by threads.

[0037] The main control module 5 is placed on the second housing 17 and is used to receive data from the femoral module IMU 24 and the tibial module IMU 25 , calculate the knee joint angle, and control the movement of the brushless DC motor 6 and the steering gear 15 .

[0038] The present invention proposes a modular knee exoskeleton system based on advanced serial elastic actuator technology, which aims to significantly improve the wearer's walking efficiency and comfort through a highly integrated and intelligently controlled design. When the wearer performs knee flexion in the gait cycle, the modular knee exoskeleton exhibits its unique separation mechanism: the modular knee exoskeleton components and the serial elastic actuator are intelligently separated. During this process, only the carefully designed elastic units inside the modular knee exoskeleton are used to provide the necessary buffering effect, effectively absorbing the impact force generated when the knee is bent, ensuring that the wearer's movements are natural and smooth. At the same time, the serial elastic actuator remains silent during this stage to avoid any unnecessary additional resistance to the wearer, thereby greatly improving the comfort and freedom of wearing.

[0039] When the wearer enters the knee extension phase of the gait cycle, the system responds quickly, and the modular knee exoskeleton seamlessly connects with the series elastic drive to form an efficient and coordinated working whole. At this time, the high-performance DC brushless motor built into the series elastic drive begins to play a role. With its precise control ability and powerful power output, it actively drives the elastic unit in the modular knee exoskeleton to perform a fast and powerful rebound action. This process not only provides a strong auxiliary power for the wearer's knee extension, effectively reducing the muscle burden during walking, but also ensures the timing and amount of power assistance through precise torque control, so that the wearer can experience a natural and smooth walking experience.

[0040] In addition, the modular knee exoskeleton system also focuses on the convenience and practicality of wearing. By adopting a modular design, the various components can be quickly and easily connected and separated, which not only greatly shortens the time required for wearing and disassembly, improves the efficiency of use, but also makes the structure of the entire exoskeleton system more concise and clear, and is easy to maintain and upgrade. At the same time, the modular design also helps to reduce the overall weight of the exoskeleton system, allowing the wearer to maintain better comfort and flexibility during long-term use, and provides unprecedented support and help for all kinds of people who need assisted walking, such as the elderly, rehabilitation patients or heavy manual laborers. In summary, the present invention not only achieves a breakthrough in technology, but also demonstrates its huge potential and value in practical applications.

[0041] Working principle, see Figure 6In the initial position, the wearer is in an upright state, at which time the first end face ratchet and the second end face ratchet are in a disengaged state, and during the flexion of the knee joint, the capstan rotates freely with the flexion of the knee joint, and the Bowden cable is wound around the capstan; when the flexion process of the knee joint is completed and the knee joint is ready to be extended, the servo rotates counterclockwise to drive the capstan push rod, the first end face ratchet and the second end face ratchet engage, the DC brushless motor starts, drives the capstan to rotate, and winds the Bowden cable into the capstan to provide assistance for the knee joint extension process, and after the knee joint is straightened, the DC brushless motor stops, the servo rotates clockwise to drive the capstan push rod, and the first end face ratchet and the second end face ratchet are separated.

[0042] Knee flexion process: When the wearer flexes the knee, the modular knee exoskeleton separates from the series elastic actuator. At this point, the elastic unit in the modular knee exoskeleton begins to absorb the energy generated during the flexion process, providing assistance for the subsequent extension movement.

[0043] The Bowden cable gradually relaxes under the action of the elastic unit, but remains connected to the capstan so that power can be re-transmitted when needed.

[0044] Knee extension process: When the wearer performs knee extension maneuvers, the modular knee exoskeleton reconnects with the series elastic actuator.

[0045] The main control module controls the start-up of the brushless DC motor based on the knee joint angle data fed back by the IMU, and tightens the Bowden cable through the reduction gear set and winch.

[0046] The Bowden cable transmits power to the modular knee exoskeleton through the driving wire and elastic unit, driving the upper driving block and the lower driving block to move relative to each other, thereby achieving extension of the knee joint.

[0047] During the stretching process, the elastic units gradually release the energy previously absorbed, providing additional assistance to the wearer.

[0048] The function of the servo: The servo controls the movement of the rack, thereby controlling the position of the capstan push rod and the servo push rod, thereby achieving precise connection and separation between the capstan and the Bowden cable.

[0049] This plays a key role in the transition between knee flexion and extension, ensuring the stability and reliability of the system.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 modular knee exoskeleton based on a series elastic actuator, characterized in that: The invention comprises a series elastic driver (1), a modular knee joint exoskeleton (2), a Bowden cable (4) and a main control module (5); the series elastic driver (1) is connected to the modular knee joint exoskeleton (2) via the Bowden cable (4); an elastic unit (23) is arranged in the modular knee joint exoskeleton (2); the elastic unit (23) is used for buffering and compressing energy storage during the flexion process of the knee joint; the main control module (5) is used for controlling the operation of the series elastic driver (1) to drive the elastic unit (23) to rebound and generate assistance.

2. A modular knee exoskeleton based on a series elastic actuator according to claim 1, characterized in that: The series elastic driver (1) comprises a brushless DC motor (6), a first reduction gear (71), a second reduction gear (72), a first end face ratchet (81), a second end face ratchet (82), a capstan (9), a steering gear (13), a steering gear housing (14), a steering gear (15), a first housing (16) and a second housing (17). The first housing (16) is provided with a motor mounting boss (28) and a steering gear mounting groove (29). The brushless DC motor (6) is mounted on the motor mounting boss (28). 28) and fixed by bolts, the output end of the brushless DC motor (6) and the motor output shaft (32) are connected by bolts, and the first reduction gear (71) is connected to the motor output shaft (32) by a flat key; the steering gear (15) is installed in the steering gear installation groove (29), the steering gear housing (14) is covered, and the steering gear housing (14) is fixed by bolts; the steering gear gear (13) is fixed to the steering gear (15) by bolt connection; the bottom of the first housing (16) is provided with a Bowden cable tube mounting seat (30); The second housing (17) is provided with a boss (33) for abutting against the first reduction gear (71); the second housing (17) is provided with a first bearing seat (34) for accommodating a first tapered roller bearing (35); one end of the gear shaft (36) is placed in the bearing hole of the first tapered roller bearing (35), and the other end is connected to the second reduction gear (72) via a flat key; The first end face ratchet (81) is fixed to the first end face ratchet mounting hole (37) on the second reduction gear (72) by means of bolts, and the second end face ratchet (82) is fixed to the second end face ratchet mounting hole (38) on the capstan (9) by means of bolts; A second bearing seat (39) is provided on the first housing (16) for accommodating a second tapered roller bearing (40); one end of the capstan shaft (41) is placed in the bearing hole of the second tapered roller bearing (40), and the other end is connected to the capstan (9) via a flat key; a compression spring (42) is provided between the capstan (9) and the shaft shoulder of the capstan shaft (41).

3. A modular knee exoskeleton based on a series elastic actuator according to claim 2, characterized in that: A steering gear push rod (11) is provided on the steering gear (15); a capstan (9) is connected to a capstan push rod (10); the capstan push rod (10) comprises a first pin mounting hole (431), a second pin mounting hole (432), a third pin mounting hole (433), and a fourth pin mounting groove (434); the first pin mounting hole (431) and the second pin mounting hole (432) form a line contact with a push rod groove (44) on the capstan (9) through a mounting pin; a push rod mounting boss (45) is provided on the first housing (16); a boss pin hole (46) is provided on the push rod mounting boss (45); the third pin mounting hole (433) is connected to the boss pin hole (46) through a pin; and the steering gear (15) is provided with a steering gear push rod. A pin mounting hole I (471), a pin mounting hole II (472), and a pin mounting hole III (473) are provided on the steering gear push rod (11). The pin mounting hole I (471) and the pin mounting hole II (472) on the steering gear push rod (11) are connected to the fourth pin mounting groove (434) on the winch push rod (10) through a pin. The pin mounting hole III (473) on the steering gear push rod (11) is connected to the rack pin hole (48) on the rack (12) through a pin. The rack (12) is placed in the rack groove (49) on the steering gear housing (14) and meshes with the steering gear gear (13) on the output shaft of the steering gear (15). The bottom of the rack (12) coincides with the bottom of the steering gear push rod (11).

4. A modular knee exoskeleton based on a series elastic actuator according to claim 2, characterized in that: The Bowden wire is arranged in a Bowden wire tube (3); one end of the Bowden wire tube (3) is fixed in a Bowden wire tube mounting seat (30) and fixed by a first wire tube fixing nut (311) and a second wire tube fixing nut (312); one end of the Bowden wire (4) is wound around a capstan (9), passes through the Bowden wire tube (3), and the other end is connected to the elastic unit (23).

5. A modular knee exoskeleton based on a series elastic actuator according to claim 2, characterized in that: The first housing (16) and the second housing (17) are connected by bolts, and countersunk holes are reserved on the housings for embedding nuts and bolt heads; countersunk holes are reserved on the side of the first housing (16) for embedding nuts when the steering gear housing (14) is fixed to the first housing (16) by bolts.

6. A modular knee exoskeleton based on a series elastic actuator according to claim 1, characterized in that: The modular knee joint exoskeleton (2) comprises a femoral fixation module (18), a tibial fixation module (19), a knee joint module (21), an elastic unit (23), a femoral module IMU (24), a tibial module IMU (25), an ankle joint module (26), a plantar module (27), an upper drive block housing (53) and a lower drive block housing (54). The upper end of the knee joint module (21) is connected to the upper drive block housing (53), and the upper drive block housing (53) is connected to the femoral fixation module (18) by a buckle. The elastic unit (23 ) is arranged inside the upper drive block housing (53); the lower end of the knee joint module (21) is connected to the lower drive block housing (54), the lower drive block housing (54) is connected to the tibial fixation module (19) via a buckle, the lower drive block housing (54) is connected to the ankle joint module (26), and the ankle joint module (26) is connected to the sole module (27) via a hinge; the femoral module IMU (24) and the tibial module IMU (25) are respectively arranged on the femoral fixation module (18) and the tibial fixation module (19), and are used to send data to the main control module.

7. A modular knee exoskeleton based on a series elastic actuator according to claim 6, characterized in that: The knee joint module (21) comprises an upper driving block (201), a lower driving block (202), an outer fixing shell (501), an inner fixing shell (502), an outer connecting rod (511), and an inner connecting rod (512); one end of the outer connecting rod (511) and the inner connecting rod (512) are connected to the upper driving block (201), and the other end is connected to the lower driving block (202); the outer fixing shell (501) and the inner fixing shell (502) are connected by threads to fix the outer connecting rod (511), the inner connecting rod (512), the upper driving block (201), and the lower driving block (202) inside; the outer connecting rod (511) and the inner connecting rod (512) are connected by a sleeve (52); the upper driving block (201) is fixed to the side of the upper driving block housing (53) by screws, and the lower driving block (202) is fixed to the side of the lower driving block housing (54) by screws.

8. A modular knee exoskeleton based on a series elastic actuator according to claim 7, characterized in that: The elastic unit (23) is arranged inside the upper drive block housing (53), and the bottom is mounted on the elastic unit base (55) of the upper drive block (201). The piston rod is connected to the piston rod connecting block (56). A Bowden wire ring (57) and a driving wire ring (58) are respectively provided on both sides of the through hole of the piston rod connecting block (56). One end of the Bowden wire (4) is fixed to the Bowden wire ring (57). One end of the driving wire (22) is fixed to the driving wire ring (58), passes through a groove on the upper drive block (201) and a wire channel inside the lower drive block (202), and the other end is fixed in the groove of the lower drive block (202). When the knee joint module (21) is bent, the driving wire (22) is tensioned and drives the elastic unit (23) to be compressed. When the knee joint module (21) is straightened, the driving wire (22) returns to its original state and the elastic unit (23) is restored.

9. A modular knee exoskeleton based on a series elastic actuator according to claim 8, characterized in that: The femoral fixation module (18) is fixed to the femur via a binding strap, and the tibial fixation module (19) is fixed to the tibia via a binding strap.

10. A modular knee exoskeleton based on a series elastic actuator according to claim 8, characterized in that: The Bowden wire connecting ring (57) passes through the through hole on the piston rod connecting block (56), and the bottom thereof is provided with an external thread, and the driving wire connecting ring (58) is provided with an internal thread, and the two are connected together by threads.

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