A passive variable stiffness energy storage assisted hip joint exoskeleton

Abstract

The present invention relates to a passive variable stiffness energy storage power-assist hip joint exoskeleton, comprising a waist and back fixing unit, a left thigh fixing unit, a right thigh fixing unit, a left variable stiffness hip joint and a right variable stiffness hip joint, wherein the left variable stiffness hip joint and the right variable stiffness hip joint both comprise a cam plate, a joint plate rotatably arranged in the cam plate, a variable stiffness adjustment mechanism arranged on the joint plate, a pair of spring energy storage mechanisms and a joint output end cover, wherein the cam plate is connected to the waist and back fixing unit, and the joint output end cover is connected to the left thigh fixing unit or the right thigh fixing unit. Compared with the prior art, the present invention stores the energy generated during a person's walking process through a spring energy storage mechanism and releases it at a certain time to achieve the purpose of power assistance, and at the same time, adjusts the overall compression amount of the spring in the spring energy storage mechanism and the position of the joint through a variable stiffness adjustment mechanism to adjust the joint output torque in real time to match the normal human hip joint torque, thereby achieving the purpose of variable stiffness.

Description

Technical Field

[0001] The present invention belongs to the technical field of lower limb exoskeletons and relates to a passive variable stiffness energy storage power-assisted hip joint exoskeleton. Background Art

[0002] China is a country with a large population. Since 2000, the aging of China's population has entered an accelerated stage. As of the end of 2017, the population over 60 years old in China accounted for 17.3% of the total population. According to the United Nations' forecast, by 2030, the number of people over 60 years old in China will exceed 300 million, and by 2050 it will climb to about 470 million. The number of people over 65 years old will increase from 170 million in 2020 to 360 million. As they age, the elderly are often accompanied by problems such as bone and joint degeneration and weakened muscle strength. The remaining muscle strength of the elderly is not enough to support their daily activities, resulting in insufficient or even absent lower limb motor function. At present, such people mainly use crutches or wheelchairs to assist in mobility, or even stay in bed at home for a long time, which will lead to a series of complications, such as pressure sores, osteoporosis, upper and lower urinary tract infections, urinary stones, muscle atrophy and spasm, etc. Therefore, standing and proper walking training are necessary.

[0003] Lower limb exoskeleton is a bionic robot worn on the lower limbs of the human body. It is a product of multidisciplinary integration. At present, the research on exoskeleton power-assisting devices is one of the current hot topics and has broad application prospects, such as military, rehabilitation and medical fields. In the field of rehabilitation, lower limb power-assisting exoskeletons mainly provide support and assistance to people with hemiplegia, paraplegia and lower limb motor dysfunction. Lower limb power-assisting exoskeletons can be classified into active, passive and semi-passive types according to the driving mode, and can be divided into single-joint power-assisting and multi-joint power-assisting according to the power-assisting joints. Although the active power-assisting exoskeleton has significant effects, it also has unavoidable defects. For example, the pneumatic drive makes it difficult to control the position and speed of the actuator due to the compressibility of air, and the stability is poor; the hydraulic drive process is complex, and the heat dissipation and leakage of hydraulic oil are difficult to solve; the motor drive is limited by the motor performance and stiffness, resulting in strong robustness and weak adaptability of the rigid drive, and there are disadvantages such as low motor torque, friction and noise. In addition, the price is usually more expensive and the battery life is short. Passive power-assisted exoskeleton has a simple structure and does not contain active drive elements. It mainly stores the energy dissipated by muscle tissue during walking through elastic elements and releases it when assistance is needed to achieve the purpose of assistance. Semi-passive power-assisted exoskeleton can fully utilize the body's own energy while providing sufficient auxiliary torque. Its drive system integrates active drive devices and energy storage units.

[0004] Developed countries entered the rehabilitation industry relatively early and have more institutions and research institutes engaged in the rehabilitation industry. Many lower limb assisted exoskeleton products have now developed from the laboratory research stage to obtaining licenses from the Food and Drug Administration and can be sold on the market. China, as a developing country, started late in the rehabilitation industry due to a series of reasons. Most of the research on lower limb assisted exoskeletons is in the experimental prototype stage or clinical trial stage. Those sold to consumers are all foreign products, which are expensive and seriously restrict the quality of life of Chinese elderly people and other people with lower limb motor dysfunction. Summary of the invention

[0005] The purpose of the present invention is to provide a passive variable stiffness energy storage assisted hip joint exoskeleton that is easy for the elderly and other people with lower limb motor dysfunction to use based on the current research status of the above-mentioned lower limb assisted exoskeleton and industry development needs.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A passive variable stiffness energy storage assisted hip joint exoskeleton, the hip joint exoskeleton comprising a waist and back fixing unit, a left thigh fixing unit, a right thigh fixing unit, a left variable stiffness hip joint arranged between the waist and back fixing unit and the left thigh fixing unit, and a right variable stiffness hip joint arranged between the waist and back fixing unit and the right thigh fixing unit, the left variable stiffness hip joint and the right variable stiffness hip joint both comprising a cam plate, a joint plate rotatably arranged in the cam plate, a variable stiffness adjustment mechanism arranged on the joint plate, a pair of spring energy storage mechanisms arranged on the variable stiffness adjustment mechanism and adapted to the cam plate, and a joint output end cover fixedly connected to the joint plate, the cam plate is connected to the waist and back fixing unit, and the joint output end cover is connected to the left thigh fixing unit or the right thigh fixing unit.

[0008] Furthermore, the waist and back fixing unit includes a back baffle, a pair of width adjustment parts, a pair of waist baffles and a pair of hip joint connecting parts. The two width adjustment parts are arranged in parallel on the side of the back baffle. One end of the waist baffle is hinged to the width adjustment part on the corresponding side, and the other end is hinged to the hip joint connecting part on the corresponding side. The hip joint connecting part is fixedly connected to the cam plate.

[0009] Preferably, an axle pin bolt is provided between one end of the waist baffle and the width adjusting member on the corresponding side, and the two ends of the waist baffle are provided with a shoulder buckle ring hinge pin and the two ends of the waist baffle are provided with a shoulder buckle ring hinge pin. The two waist baffles are respectively a left waist baffle and a right waist baffle, and the waist baffles are also provided with plastic buckles for easy disassembly and assembly.

[0010] Further, the left thigh fixing unit comprises a left thigh aluminum alloy support bar, the top of which is provided with a joint output connector, and is fixedly connected to the joint output end cover on the corresponding side through the joint output connector, and a thigh hoop is provided at the bottom of the left thigh aluminum alloy support bar; the right thigh fixing unit comprises a right thigh aluminum alloy support bar, the top of which is provided with a joint output connector, and is fixedly connected to the joint output end cover on the corresponding side through the joint output connector, and a thigh hoop is provided at the bottom of the right thigh aluminum alloy support bar.

[0011] Furthermore, the cam plate includes a cam plate base plate and a cam plate annular side plate arranged on the cam plate base plate, a cam plate guide portion is provided on the inner side of the cam plate annular side plate, the distance between the inner side of the cam plate guide portion and the center of the cam plate annular side plate gradually increases or decreases along the circumferential direction, and the spring energy storage mechanism is provided with a cam follower adapted to the cam plate guide portion.

[0012] Furthermore, a thrust needle roller bearing and a second small-diameter ball bearing are provided on the cam disc bottom plate, the joint disc is sleeved on the second small-diameter ball bearing, and the thrust needle roller bearing is located between the cam disc bottom plate and the bottom of the joint disc.

[0013] Preferably, the second small-diameter ball bearing and the top of the joint disc are provided with an inner flange and an outer flange.

[0014] Furthermore, the variable stiffness adjustment mechanism includes a motor base arranged on the joint disc, a motor arranged on the motor base, a reducer transmission-connected to the output shaft of the motor, a worm gear assembly transmission-connected to the reducer, and a pair of screw nut assemblies, the two screw nut assemblies are respectively arranged at both ends of the worm gear assembly, and are respectively adapted to the spring energy storage mechanism on the corresponding side.

[0015] Furthermore, the worm gear assembly includes a worm shaft connected to the reducer transmission, a worm sleeved on the worm shaft, and a worm wheel arranged above the worm and meshing with the worm, a worm support seat is provided on the joint disc, and a third small-diameter ball bearing is provided between one end of the worm shaft and the worm support seat.

[0016] Furthermore, the screw nut assembly includes a trapezoidal screw arranged at the end of the worm gear, and a screw nut and a screw support seat which are arranged in parallel on the trapezoidal screw. A first small-diameter ball bearing is provided between the screw support seat and the trapezoidal screw, and the screw nut is located between the screw support seat and the spring energy storage mechanism on the corresponding side.

[0017] Preferably, the trapezoidal screw threads of the two screw-nut assemblies have opposite rotation directions, and the two screw nuts are respectively a left-handed screw nut and a right-handed screw nut.

[0018] Furthermore, the spring energy storage mechanism includes a pair of optical axes arranged in parallel, a rectangular mold spring sleeved on the optical axes, and a passive variable stiffness adjustment seat arranged at one end of the two optical axes, the other end of the optical axis passes through the screw nut and is fixedly connected to the screw support seat, and the cam follower is arranged on the passive variable stiffness adjustment seat.

[0019] Furthermore, an absolute encoder is provided on the joint disc, a gear is provided on the output shaft of the absolute encoder, and an arc-shaped rack meshing with the gear is also provided on the inner side of the annular side plate of the cam disc.

[0020] Preferably, the joint disc is further provided with a plurality of joint disc connecting columns, and the joint output end cover is fixedly connected to the joint disc connecting columns.

[0021] In the present invention, the left and right variable stiffness hip joints utilize the change in the radius of curvature of the contour line of the cam plate guide part to compress the rectangular mold spring during the movement of the cam follower driven by the lower limbs of the human body, thereby achieving the purpose of energy storage; and during the reverse movement, the spring returns to its original length to achieve the purpose of assisting. In order to make the gait of a person more natural during walking, a micro motor is added inside the joint to adjust the overall compression of the rectangular mold spring so that the joint output torque matches the torque of a normal person during walking, thereby achieving the purpose of online real-time adjustment of the hip joint stiffness. A worm gear assembly and a lead screw nut assembly are used to increase the motor output torque. Due to the reduction in motor power, the overall endurance of the hip joint is improved. At the same time, in order to adjust the stiffness online and in real time according to the position of the joint during movement, an absolute encoder is installed on the joint disc. When the joint disc rotates relative to the cam disc, the relative rotation angle can be measured, thereby performing effective position control.

[0022] Compared with the prior art, the present invention has the following characteristics:

[0023] 1) The left and right waist baffles of the passive variable stiffness energy storage power-assisting hip joint exoskeleton in the present invention are connected to the width adjustment piece through an axle pin bolt, and can follow the change of the center of gravity of a person walking by rotating along the sagittal axis. The left and right variable stiffness hip joints are connected to the left and right waist baffles through a shoulder buckle hinge pin and a hip joint connector to achieve the adduction and abduction functions of the hip joint, and the width adjustment piece is connected to the back baffle by screws. The hip joint of the exoskeleton stores the energy generated during the walking process of a person by using a linear spring and releases it at a certain time to achieve the purpose of power assistance. At the same time, the overall compression of the spring and the position of the joint are adjusted by a micromotor to adjust the joint output torque in real time to match the normal human hip joint torque, thereby achieving the purpose of variable stiffness.

[0024] 2) In the present invention, the passive variable stiffness hip joint exoskeleton has three degrees of freedom, which respectively realize the flexion and extension of the hip joint, the adduction and abduction of the hip joint, and the up and down movement of the waist center of gravity. The width of the hip joint exoskeleton can be adjusted by adjusting the fixed position between the back baffle of the exoskeleton and the width adjustment piece to adapt to people of different body shapes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a front view of the passive variable stiffness energy storage power-assisting hip joint exoskeleton of the present invention;

[0026] Figure 2 This is a schematic diagram of the overall structure of the passive variable stiffness energy storage power-assisted hip joint exoskeleton of the present invention;

[0027] Figure 3 It is a schematic diagram of the structure of the left and right variable stiffness hip joints in the present invention;

[0028] Figure 4 It is a schematic cross-sectional structure diagram of the left and right variable stiffness hip joints along the axis of the trapezoidal screw in the present invention;

[0029] Figure 5 It is a schematic cross-sectional structure diagram of the left and right variable stiffness hip joints along the axis of the worm in the present invention;

[0030] Description of the markings in the figure:

[0031] 1—axle pin bolt, 2—waist baffle, 3—hinge pin with shoulder buckle, 4—left variable stiffness hip joint, 5—left thigh aluminum alloy support bar, 6—thigh hoop, 7—right thigh aluminum alloy support bar, 8—joint output connector, 9—joint output end cover, 10—right variable stiffness hip joint, 11—plastic buckle, 12—width adjustment piece, 13—back baffle, 14—hip joint connector, 15—joint disc connecting column, 16—cam follower, 17—cam disc, 18—reducer, 19—motor, 20—motor base, 21—worm, 22—worm gear , 23—passive variable stiffness adjustment seat, 24—trapezoidal screw, 25—gear, 26—rectangular mold spring, 27—left-hand screw nut, 28—screw support seat, 29—right-hand screw nut, 30—optical axis, 31—first small-diameter ball bearing, 32—outer flange, 33—inner flange, 34—second small-diameter ball bearing, 35—thrust needle roller bearing, 36—worm support seat, 37—absolute encoder, 38—third small-diameter ball bearing, 39—worm shaft, 40—joint disc, 41—cam disc guide, 42—arc rack. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0033] Embodiment 1:

[0034] like Figure 1 , 2 As shown, the passive variable stiffness energy storage assisted hip joint exoskeleton includes: an axle pin bolt 1, a waist baffle 2, a hinge pin with a shoulder buckle 3, a left variable stiffness hip joint 4, a left thigh aluminum alloy support bar 5, a thigh hoop 6, a right thigh aluminum alloy support bar 7, a joint output connector 8, a joint output end cover 9, a right variable stiffness hip joint 10, a plastic buckle 11, a width adjustment part 12, a back baffle 13, a hip joint connector 14, etc.

[0035] The left and right hip joint exoskeleton are mirror-symmetrical. Taking the left part as an example, the width adjustment member 12 is fixed to the back baffle 13 by screws, and the waist baffle 2 is connected to the width adjustment member 12 by the axle pin bolt 1, so that the waist baffle 2 can rotate along the axis direction of the axle pin bolt 1. The hip joint connecting member 14 is connected to the waist baffle 2 by the hinge pin 3 with shoulder buckle ring, so that the hip joint can rotate along the sagittal axis. The left variable stiffness hip joint 4 is fixed to the hip joint connecting member 14 by screws, and the joint output end cover 9 is fixed to the left variable stiffness hip joint 4 by screws. The joint output connecting member 8 is fixed to the joint output end cover 9 by screws, which is used to adjust the position of the thigh aluminum alloy support bar. The left thigh aluminum alloy support bar 5 is fixed to the joint output connecting member 8 by screws, and the thigh hoop 6 is directly connected to the left thigh aluminum alloy support bar 5.

[0036] like Figure 3 , Figure 4 , Figure 5 As shown, the variable stiffness hip joint includes: an articular disc 40, a cam follower 16, a cam disc 17, a reducer 18, a motor 19, a motor base 20, a worm 21, a worm wheel 22, a passive variable stiffness adjustment seat 23, a trapezoidal screw 24, a gear 25, a rectangular mold spring 26, a left-handed screw nut 27, a screw support seat 28, a right-handed screw nut 29, an optical axis 30, a first small-diameter ball bearing 31, an outer flange 32, an inner flange 33, a second small-diameter ball bearing 34, a thrust needle roller bearing 35, a worm support seat 36, an absolute encoder 37, a third small-diameter ball bearing 38, and a worm shaft 39.

[0037] The output end of the motor 19 is connected to the reducer 18 and fixed on the motor base 20. The output shaft of the reducer 18 is connected to the worm 21 through the worm shaft 39. The other end of the worm shaft 39 is installed on the worm support seat 36 through the third small-diameter ball bearing 38. The worm 21 is fixed to the worm shaft 39 by screws. The worm wheel 22 is meshed with the worm 21 for transmission. The trapezoidal lead screw 24 is fixed to the worm wheel 22 by screws and is installed on the lead screw support seat 28 with the first small-diameter ball bearing 31. The two ends of the trapezoidal lead screw 24 rotate in opposite directions and are respectively connected to two lead screw nuts with opposite rotation directions. One end of the four optical axes 30 passes through the lead screw nut and is fixed to the lead screw support seat 28. Four rectangular mold springs 26 are nested on the optical axis 30. The optical axis 30 The other end is connected to the passive variable stiffness adjustment seat 23 with a shaft sleeve, and the cam follower 16 is installed on the passive variable stiffness adjustment seat 23 through a thread and contacts the contour line of the cam plate guide portion 41 on the cam plate 17. The joint plate 40 is connected to the cam plate 17 through a thrust needle roller bearing 35 and a second small-diameter ball bearing 34 to achieve relative rotation of the joint plate 40 on the cam plate 17. The second small-diameter ball bearing 34 is axially fixed by an outer flange 32 and an inner flange 33. An absolute encoder 37 is installed on the joint plate 40, and an output shaft of the absolute encoder 37 is connected to the gear 25 and circumferentially positioned with screws. The gear 25 engages with the arc rack 42 on the cam plate 17 to measure the joint angle.

[0038] Embodiment 2:

[0039] like Figure 1 , Figure 2 A passive variable stiffness energy storage assisted hip joint exoskeleton shown includes a waist and back fixation unit, a left thigh fixation unit, a right thigh fixation unit, a left variable stiffness hip joint 4 arranged between the waist and back fixation unit and the left thigh fixation unit, and a right variable stiffness hip joint 10 arranged between the waist and back fixation unit and the right thigh fixation unit. The left variable stiffness hip joint 4 and the right variable stiffness hip joint 10 both include a cam plate 17, a joint plate 40 rotatably arranged in the cam plate 17, a variable stiffness adjustment mechanism arranged on the joint plate 40, a pair of spring energy storage mechanisms arranged on the variable stiffness adjustment mechanism and adapted to the cam plate 17, and a joint output end cover 9 fixedly connected to the joint plate 40. The cam plate 17 is connected to the waist and back fixation unit, and the joint output end cover 9 is connected to the left thigh fixation unit or the right thigh fixation unit.

[0040] The waist and back fixing unit includes a back baffle 13, a pair of width adjusting members 12, a pair of waist baffles 2 and a pair of hip joint connecting members 14. The two width adjusting members 12 are arranged side by side on the side of the back baffle 13. One end of the waist baffle 2 is hinged to the width adjusting member 12 on the corresponding side, and the other end is hinged to the hip joint connecting member 14 on the corresponding side. The hip joint connecting member 14 is fixedly connected to the cam plate 17. An axle pin bolt 1 is arranged between one end of the waist baffle 2 and the width adjusting member 12 on the corresponding side, and the two ends are hinged to the hip joint connecting member 14 on the corresponding side. The two waist baffles 2 are respectively a left waist baffle and a right waist baffle. The waist baffle 2 is also provided with a plastic buckle 11 for easy disassembly and assembly.

[0041] The left thigh fixing unit includes a left thigh aluminum alloy support bar 5, a joint output connector 8 is provided on the top of the left thigh aluminum alloy support bar 5, and the joint output connector 8 is fixedly connected to the joint output end cover 9 on the corresponding side through the joint output connector 8, and a thigh hoop 6 is provided on the bottom of the left thigh aluminum alloy support bar 5; the right thigh fixing unit includes a right thigh aluminum alloy support bar 7, a joint output connector 8 is provided on the top of the right thigh aluminum alloy support bar 7, and the joint output connector 8 is fixedly connected to the joint output end cover 9 on the corresponding side through the joint output connector 8, and a thigh hoop 6 is provided on the bottom of the right thigh aluminum alloy support bar 7.

[0042] like Figure 3 , Figure 4 , Figure 5 As shown, the cam disc 17 includes a cam disc bottom plate and a cam disc annular side plate arranged on the cam disc bottom plate, a cam disc guide portion 41 is arranged on the inner side of the cam disc annular side plate, the distance between the inner side of the cam disc guide portion 41 and the center of the cam disc annular side plate gradually increases or decreases along the circumferential direction, and a cam follower 16 adapted to the cam disc guide portion 41 is arranged on the spring energy storage mechanism. A thrust needle roller bearing 35 and a second small-diameter ball bearing 34 are arranged on the cam disc bottom plate, the joint disc 40 is sleeved on the second small-diameter ball bearing 34, and the thrust needle roller bearing 35 is located between the cam disc bottom plate and the bottom of the joint disc 40. An inner flange 33 and an outer flange 32 are arranged on the second small-diameter ball bearing 34 and the top of the joint disc 40.

[0043] The variable stiffness adjustment mechanism includes a motor base 20 arranged on a joint disc 40, a motor 19 arranged on the motor base 20, a reducer 18 drivingly connected to the output shaft of the motor 19, a worm gear assembly drivingly connected to the reducer 18, and a pair of lead screw nut assemblies, the two lead screw nut assemblies are respectively arranged at the two ends of the worm gear assembly, and are respectively adapted to the spring energy storage mechanism on the corresponding side. The worm gear assembly includes a worm shaft 39 drivingly connected to the reducer 18, a worm 21 sleeved on the worm shaft 39, and a worm wheel 22 arranged above the worm 21 and meshing with the worm 21, a worm support seat 36 is arranged on the joint disc 40, and a third small-diameter ball bearing 38 is arranged between one end of the worm shaft 39 and the worm support seat 36. The screw nut assembly includes a trapezoidal screw 24 disposed at the end of the worm gear 22, a screw nut and a screw support seat 28 which are arranged in parallel on the trapezoidal screw 24, a first small-diameter ball bearing 31 is arranged between the screw support seat 28 and the trapezoidal screw 24, and the screw nut is located between the screw support seat 28 and the spring energy storage mechanism on the corresponding side. The thread rotation directions of the trapezoidal screws 24 of the two screw nut assemblies are opposite, and the two screw nuts are respectively a left-hand screw nut 27 and a right-hand screw nut 29.

[0044] The spring energy storage mechanism includes a pair of optical axes 30 arranged in parallel, a rectangular mold spring 26 sleeved on the optical axes 30, and a passive variable stiffness adjustment seat 23 set at one end of the two optical axes 30, the other end of the optical axis 30 passes through the screw nut and is fixedly connected to the screw support seat 28, and the cam follower 16 is set on the passive variable stiffness adjustment seat 23.

[0045] The joint disc 40 is provided with an absolute encoder 37, the output shaft of which is provided with a gear 25, and the inner side of the annular side plate of the cam disc is also provided with an arc-shaped rack 42 meshing with the gear 25. The joint disc 40 is also provided with a plurality of joint disc connecting columns 15, and the joint output end cover 9 is fixedly connected to the joint disc connecting columns 15.

[0046] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A passive variable stiffness energy storage assisted hip joint exoskeleton, It is characterized in that The hip joint exoskeleton comprises a waist and back fixing unit, a left thigh fixing unit, a right thigh fixing unit, a left variable stiffness hip joint (4) arranged between the waist and back fixing unit and the left thigh fixing unit, and a right variable stiffness hip joint (10) arranged between the waist and back fixing unit and the right thigh fixing unit, wherein the left variable stiffness hip joint (4) and the right variable stiffness hip joint (10) both comprise a cam plate (17), a joint plate (40) rotatably arranged in the cam plate (17), a variable stiffness adjustment mechanism arranged on the joint plate (40), a pair of spring energy storage mechanisms arranged on the variable stiffness adjustment mechanism and adapted to the cam plate (17), and a joint output end cover (9) fixedly connected to the joint plate (40), wherein the cam plate (17) is connected to the waist and back fixing unit, and the joint output end cover (9) is connected to the left thigh fixing unit or the right thigh fixing unit; The cam disc (17) comprises a cam disc bottom plate and a cam disc annular side plate arranged on the cam disc bottom plate, a cam disc guide portion (41) is provided on the inner side of the cam disc annular side plate, the distance between the inner side of the cam disc guide portion (41) and the center of the cam disc annular side plate gradually increases or decreases along the circumferential direction, and a cam follower (16) adapted to the cam disc guide portion (41) is provided on the spring energy storage mechanism; The variable stiffness adjustment mechanism comprises a motor base (20) arranged on the joint disc (40), a motor (19) arranged on the motor base (20), a reducer (18) drivingly connected to the output shaft of the motor (19), a worm gear assembly drivingly connected to the reducer (18), and a pair of lead screw nut assemblies, wherein the two lead screw nut assemblies are respectively arranged at two ends of the worm gear assembly and are respectively adapted to the spring energy storage mechanism on the corresponding side; The worm gear assembly comprises a worm shaft (39) drivingly connected to the reducer (18), a worm (21) sleeved on the worm shaft (39), and a worm wheel (22) arranged above the worm (21) and meshing with the worm (21); a worm support seat (36) is provided on the joint disc (40); and a third small-diameter ball bearing (38) is provided between one end of the worm shaft (39) and the worm support seat (36); The screw nut assembly comprises a trapezoidal screw (24) arranged at the end of the worm gear (22), a screw nut and a screw support seat (28) which are arranged in parallel on the trapezoidal screw (24), and a first small-diameter ball bearing (31) is provided between the screw support seat (28) and the trapezoidal screw (24); The spring energy storage mechanism comprises a pair of optical axes (30) arranged in parallel, a rectangular mold spring (26) sleeved on the optical axes (30), and a passive variable stiffness adjustment seat (23) arranged at one end of the two optical axes (30), the other end of the optical axis (30) is fixedly connected to the lead screw nut assembly, and the cam follower (16) is arranged on the passive variable stiffness adjustment seat (23) and contacts the contour line of the cam plate guide portion (41) on the cam plate (17).

2. A passive variable stiffness energy storage assisted hip joint exoskeleton according to claim 1, It is characterized in that The waist and back fixing unit comprises a back baffle (13), a pair of width adjustment members (12), a pair of waist baffles (2) and a pair of hip joint connecting members (14), wherein the two width adjustment members (12) are arranged in parallel on the side of the back baffle (13), one end of the waist baffle (2) is hinged to the width adjustment member (12) on the corresponding side, and the other end is hinged to the hip joint connecting member (14) on the corresponding side, and the hip joint connecting member (14) is fixedly connected to the cam plate (17).

3. A passive variable stiffness energy storage assisted hip joint exoskeleton according to claim 1, It is characterized in that The left thigh fixing unit comprises a left thigh aluminum alloy support bar (5), the top of the left thigh aluminum alloy support bar (5) is provided with a joint output connector (8) and is fixedly connected to a joint output end cover (9) on a corresponding side via the joint output connector (8), and the bottom of the left thigh aluminum alloy support bar (5) is provided with a thigh hoop (6); The right thigh fixing unit comprises a right thigh aluminum alloy support bar (7), the top of which is provided with a joint output connector (8) and is fixedly connected to a joint output end cover (9) on a corresponding side via the joint output connector (8), and the bottom of the right thigh aluminum alloy support bar (7) is provided with a thigh hoop (6).

4. A passive variable stiffness energy storage assisted hip joint exoskeleton according to claim 1, It is characterized in that A thrust needle roller bearing (35) and a second small-diameter ball bearing (34) are provided on the cam disc bottom plate, the joint disc (40) is sleeved on the second small-diameter ball bearing (34), and the thrust needle roller bearing (35) is located between the cam disc bottom plate and the bottom of the joint disc (40).

5. A passive variable stiffness energy storage assisted hip joint exoskeleton according to claim 1, It is characterized in that An absolute encoder (37) is provided on the joint disc (40), a gear (25) is provided on the output shaft of the absolute encoder (37), and an arc-shaped rack (42) meshing with the gear (25) is also provided on the inner side of the annular side plate of the cam disc.

Images