A quasi-passive variable stiffness energy storage assisted hip joint exoskeleton

Abstract

The present invention relates to a quasi-passive variable stiffness energy storage and assisted hip joint exoskeleton, comprising a fixed waist belt, a right exoskeleton and a left exoskeleton, wherein the right exoskeleton and the left exoskeleton are symmetrically designed. Compared with the prior art, when the wearer wears the exoskeleton and walks, when the hip joint is extended, the moving lower limbs will drive the knee joint assembly and the thigh support rod to move, thereby causing the cam moving roller of the output chassis and the screw assembly to rotate relative to the fixed waist belt and the cam disc assembly. The cam moving roller will move along the contour line of the specially designed cam disc to compress the heavy-loaded spring to store energy, and release it when the hip joint is flexed and stepped forward to achieve walking assistance. In addition, the position of the screw nut is adjusted by a motor to change the pre-compression amount of the heavy-loaded spring to increase the stiffness of the entire variable stiffness joint, thereby enabling the exoskeleton to have the ability to adjust the auxiliary stiffness according to wearers of different heights, weights, and walking speeds.

Description

Technical Field

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

[0002] my country has entered a period of rapid aging. With increasing age, the physical functions of the elderly continue to decline, and problems such as bone and joint degeneration and weakened muscle strength gradually affect their daily activities. This is manifested in a decline in the mobility of the elderly and a weakening of lower limb motor function, while the probability of injuries from falls also increases with age. The elderly are also a high-risk group for stroke, and stroke is often accompanied by upper or lower limb dysfunction, which seriously affects the health and self-care ability of the elderly, while also placing a huge economic burden on families and society. Lower limb walking exoskeletons can effectively help the elderly reduce the burden of walking, enhance walking ability, and assist in physical activities. The development of lower limb walking exoskeletons not only helps solve the problems of exercise assistance and exercise rehabilitation for the elderly, but also effectively alleviates the care pressure of medical staff and family members.

[0003] Lower-limb power-assist exoskeletons can be categorized as active and passive based on their driving force. Active exoskeletons use motors, pneumatics, and other energy sources, rely on sensors to sense the wearer's movement intentions, and provide power assistance guided by control strategies. However, active exoskeletons rely on external power sources, are bulky, and are expensive, leading to a bottleneck in related research. Passive exoskeletons, on the other hand, harvest the body's own energy for propulsion, enabling energy recycling during walking. Their structural design is simpler, lighter, and more affordable, but current passive exoskeletons often employ a fixed stiffness approach. This means the stiffness exhibited during power assistance is fixed and cannot be adjusted to accommodate wearers of varying heights, weights, and gait speeds. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a quasi-passive variable stiffness energy storage assisted hip joint exoskeleton.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A quasi-passive variable stiffness energy storage power-assisted hip joint exoskeleton, comprising a fixed waist belt, a right exoskeleton and a left exoskeleton, wherein the right exoskeleton and the left exoskeleton are symmetrically designed;

[0007] The right exoskeleton includes a right variable stiffness joint, a right thigh support rod, a right knee joint assembly, and a right knee joint strap. The upper and lower ends of the right thigh support rod are respectively connected to the right variable stiffness joint and the right knee joint assembly. The right knee joint strap is connected to the right knee joint assembly through a strap reserved hole of the right knee joint assembly.

[0008] The right variable stiffness joint includes a right joint connection input component, a right cam disc component, a right output chassis component, a right lead screw spring component, and a right motor component. The upper end of the right joint connection input component is provided with a waist belt reserved hole adapted to the fixed waist belt. The lower end of the right joint connection input component is provided with a joint connection input disc. The right cam disc component is fixedly connected to the joint connection input disc. The two sides of the right output chassis component are respectively connected to the right cam disc component and the right lead screw spring component. The right lead screw spring component is connected to the right cam disc component. The right motor assembly is installed on the right output chassis. The output end of the right motor assembly is connected to the right lead screw spring assembly. The upper end of the right thigh support rod is connected to the bottom end of the right output chassis assembly.

[0009] When the wearer walks, the hip joint extends and drives the right thigh support rod to move, causing the right output chassis assembly to rotate relative to the right cam plate assembly. The right screw spring assembly connected to the right output chassis assembly rotates accordingly and changes the spring compression of the right screw spring assembly. The output end of the right motor assembly drives the screw nut of the right screw spring assembly to move and changes the spring compression of the right screw spring assembly.

[0010] The left exoskeleton includes a left variable stiffness joint, a left thigh support rod, a left knee joint assembly, and a left knee joint strap. The upper and lower ends of the left thigh support rod are respectively connected to the left variable stiffness joint and the left knee joint assembly. The left knee joint strap is connected to the left knee joint assembly through a strap reserved hole of the left knee joint assembly.

[0011] The left variable stiffness joint includes a left joint connection input component, a left cam disc component, a left output chassis component, a left lead screw spring component, and a left motor component. The upper end of the left joint connection input component is provided with a waist belt reserved hole adapted for the fixed waist belt. The lower end of the left joint connection input component is provided with a joint connection input disc. The left cam disc component is fixedly connected to the joint connection input disc. The two sides of the left output chassis component are respectively connected to the left cam disc component and the left lead screw spring component. The left lead screw spring component is connected to the left cam disc component. The left motor assembly is installed on the left output chassis. The output end of the left motor assembly is connected to the left lead screw spring assembly. The upper end of the left thigh support rod is connected to the bottom end of the left output chassis assembly.

[0012] When the wearer walks, the hip joint extends and drives the left thigh support rod to move, causing the left output chassis assembly to rotate relative to the left cam plate assembly, and the left screw spring assembly connected to the left output chassis assembly rotates accordingly and changes the spring compression amount of the left screw spring assembly; the output end of the left motor assembly drives the screw nut of the left screw spring assembly to move and changes the spring compression amount of the left screw spring assembly.

[0013] Furthermore, the right joint connection input assembly has the same structure as the left joint connection input assembly. A circular groove is provided at the center of the joint connection input disk. A protruding short rod is provided at the center of the circular groove. The short rod is a hollow structure. A magnetic cylinder is provided inside the short rod. The magnetic cylinder and the short rod have an interference fit.

[0014] The right variable stiffness joint further includes a right rotary magnetic encoder, and the left variable stiffness joint further includes a left rotary magnetic encoder. The right rotary magnetic encoder is mounted on the right cam disc assembly, and the left rotary magnetic encoder is mounted on the left cam disc assembly.

[0015] Furthermore, the right cam disc assembly and the left cam disc assembly are symmetrically designed, and the right cam disc assembly includes a right cam disc, a cam disc connecting screw, a flange bearing and a plane needle roller bearing. The right cam disc is fixedly connected to the joint connection input disc by the cam disc connecting screw. A stepped through hole is provided at the center of the disc surface of the right cam disc. The flange bearing and the plane needle roller bearing are installed in the stepped through hole. The right cam disc assembly and the right output chassis assembly are matched with each other through the plane needle roller bearing and the flange bearing. The size of the stepped through hole near the side of the joint connection input disc matches the size of the circular groove in the center of the joint connection input disc. Arc-shaped notches are respectively provided on the upper and lower sides of the center of the disc surface of the right cam disc.

[0016] The left cam disc assembly includes a left cam disc, a cam disc connecting screw, a flange bearing and a plane needle roller bearing. The left cam disc is fixedly connected to the joint connection input disc by the cam disc connecting screw. A stepped through hole is provided in the center of the disc surface of the left cam disc. The flange bearing and the plane needle roller bearing are installed in the stepped through hole. The left cam disc assembly and the left output chassis assembly are connected through the plane needle roller bearing and the flange bearing. The size of the stepped through hole near the side of the joint connection input disc matches the size of the circular groove in the center of the joint connection input disc. Arc-shaped notches are respectively provided on the upper and lower sides of the center of the disc surface of the left cam disc.

[0017] Furthermore, the upper and lower sides of the center of the joint connection input disc are provided with avoidance grooves adapted to the two arc-shaped notches of the right cam disc;

[0018] or,

[0019] An avoidance groove adapted to the arc-shaped notch on the lower side of the right cam disc is provided on the lower side of the center of the surface of the joint connection input disc.

[0020] Furthermore, the right output chassis assembly and the left output chassis assembly are symmetrically designed, and the right output chassis assembly includes a right output chassis, a first right connecting section, a second right connecting section, a first roller, a second roller, and a first retaining spring. The first right connecting section and the second right connecting section extend from the upper end and the lower end of the right output chassis respectively, and the right thigh support rod is connected to the second right connecting section. A stepped main shaft adapted to the right cam plate assembly is provided at the center of the right output chassis; roller mounting holes and roller slots are provided on both sides of the main shaft respectively, and the first roller is mounted on the right output chassis through the roller mounting hole, and the first roller The side surface contacts the upper contour line of the upper arc-shaped notch on the right cam disc, and the size of the roller notch is adapted to the second roller, which is installed on the right screw spring assembly; the main shaft passes through the plane needle bearing and the flange bearing in the stepped through hole in the center of the right cam disc assembly in sequence, and the top of the main shaft is provided with a retaining ring groove, and the first retaining ring is installed in the retaining ring groove and presses the inner ring of the flange bearing to limit the axial position of the right cam disc assembly. The circular groove in the center of the joint connection input disc is adapted to the outer ring of the flange bearing, and the main shaft is a hollow sleeve, and the short rod is inserted into the main shaft, and the short rod and the main shaft are matched and connected;

[0021] The left output chassis assembly includes a left output chassis, a left first connecting section, a left second connecting section, a first roller, a second roller, and a first retaining spring. The left first connecting section and the left second connecting section extend from the upper end and the lower end of the left output chassis respectively. The left thigh support rod is connected to the left second connecting section. A stepped main shaft adapted to the left cam disc assembly is provided at the center of the left output chassis; roller mounting holes and roller slots are respectively provided on both sides of the main shaft, and the first roller is installed on the left output chassis through the roller mounting hole, and the side surface of the first roller contacts the upper arc on the left cam disc. The upper side contour line of the shaped slot, the size of the roller slot is adapted to the second roller, and the second roller is installed on the left screw spring assembly; the main shaft passes through the plane needle bearing and the flange bearing in the stepped through hole in the center of the left cam disc assembly in sequence, and the top of the main shaft is provided with a retaining ring groove, the first retaining ring is installed in the retaining ring groove and presses the inner ring of the flange bearing to limit the axial position of the left cam disc assembly, the circular groove in the center of the joint connection input disc is adapted to the outer ring of the flange bearing, the main shaft is a hollow sleeve, the short rod is inserted into the main shaft, and the short rod and the main shaft are matched and connected.

[0022] Furthermore, the right screw spring assembly has the same structure as the left screw spring assembly, the right screw spring assembly includes a large gear, a screw front shaft sleeve, a screw front support, a guide shaft connecting plate, a trapezoidal screw, a screw nut, a guide shaft, a heavy-load spring, a screw rear shaft sleeve, a screw rear support, a roller connecting piece, and a spring sleeve, the large gear is cooperated with the screw front shaft sleeve, the screw front shaft sleeve is cooperated with the screw front support, the screw rear shaft sleeve is cooperated with the screw rear support, the screw front support and the screw rear support are respectively installed on the right first connecting section and the right second connecting section, one end of the trapezoidal screw penetrates the screw front shaft sleeve and is cooperated with the screw front shaft sleeve, the other end of the trapezoidal screw penetrates the screw rear shaft sleeve and is cooperated with the screw rear shaft sleeve, the spring sleeve is connected to the right cam plate by a screw, the heavy-load spring is arranged in the accommodating space formed between the spring sleeve and the right cam plate, and the screw front support and the screw rear support are arranged outside the accommodating space formed between the spring sleeve and the right cam plate;

[0023] The heavy-duty spring is sleeved on the trapezoidal lead screw, and the two ends of the heavy-duty spring are respectively connected to the lead screw nut and the roller connector. The lead screw nut is sleeved on the trapezoidal lead screw and cooperates with the trapezoidal lead screw thread. The roller connector is sleeved on the trapezoidal lead screw. The second roller is connected to the roller connector. After passing through the roller slot, the second roller cooperates with the right output chassis. The side surface of the second roller contacts the lower side contour line of the lower arc-shaped slot on the right cam plate.

[0024] The screw nut is also provided with a guide hole adapted to the guide shaft. One end of the guide shaft is connected to the guide shaft connecting piece, and the other end is connected to the spring sleeve after passing through the guide hole. The guide shaft connecting piece is installed on the front support of the screw. The rotation of the large gear drives the trapezoidal screw to rotate, and the screw nut moves along the trapezoidal screw as the trapezoidal screw rotates.

[0025] Furthermore, the right motor assembly has the same structure as the left motor assembly, and the right motor assembly includes a pinion, a motor front support, a motor sleeve, a motor rear support, and a motor. The pinion is meshed with the large gear, and the pinion is connected to the motor sleeve. The motor sleeve is connected to the motor front support. The motor is installed on the motor rear support. The motor front support and the motor rear support are installed in the first connecting section on the right side. The output shaft of the motor passes through the motor sleeve and is connected to the motor sleeve. The motor output shaft drives the pinion to rotate.

[0026] Furthermore, the right variable stiffness joint also includes a right protective shell, and the left variable stiffness joint also includes a left protective shell. The right protective shell and the left protective shell have the same structure. The right protective shell is installed on the right first connecting section, and the large gear, small gear, screw front support and motor front support are all arranged in the accommodating space formed between the right protective shell and the right first connecting section.

[0027] Furthermore, the right knee joint assembly has the same structure as the left knee joint assembly. The right knee joint assembly includes an upper knee joint and a lower knee joint. The upper knee joint and the lower knee joint are rotatably connected. The upper knee joint is connected to the right thigh support rod, and the lower knee joint is provided with a strap reserved hole adapted to the right knee joint strap.

[0028] Furthermore, arc-shaped notches are provided on the upper and lower sides of the center of the right cam disc. The upper arc-shaped notch is an arc with an opening angle of 120 degrees, and the contour line of the lower arc-shaped notch is designed as a special function. It is divided into two arcs in total, which are expressed as follows in polar coordinates with the center of the right cam disc as the origin:

[0029]

[0030] Among them, θ represents the angular coordinate in polar coordinates, and r represents the radius coordinate in polar coordinates;

[0031] Arc-shaped notches are provided on the upper and lower sides of the center of the left cam disc. The upper arc-shaped notch is an arc with an opening angle of 120 degrees. The contour line of the lower arc-shaped notch is designed as a special function and is divided into two arc segments. The polar coordinates with the center of the left cam disc as the origin are expressed as follows:

[0032]

[0033] Wherein, θ represents the angular coordinate in polar coordinates, and r represents the radius coordinate in polar coordinates.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) When the wearer walks while wearing the exoskeleton, when the hip joint is extended, the moving lower limbs will drive the knee joint assembly and the thigh support rod to move, thereby causing the cam moving roller of the output chassis and the screw assembly to rotate relative to the fixed belt and cam disc assembly. The cam moving roller will move along the contour of the specially designed cam disc to compress the heavy-load spring to store energy, and release it when the hip joint is flexed and steps forward to achieve walking assistance. In addition, the position of the screw nut is adjusted by the motor to change the pre-compression amount of the heavy-load spring to increase the stiffness of the entire variable stiffness joint, so that the exoskeleton has the ability to adjust the assistance stiffness according to the wearer's height, weight, and walking speed, thereby achieving a personalized assistance effect.

[0036] (2) An innovative lightweight structural design for the hip exoskeleton was proposed, and the contour line of the cam disc in the variable stiffness joint was precisely designed to more reasonably collect the energy dissipated during walking and release it when taking steps to assist walking. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of a quasi-passive variable stiffness energy storage assisted hip exoskeleton;

[0038] Figure 2 Schematic diagram of the variable stiffness joint on the right;

[0039] Figure 3 Schematic diagram of the variable stiffness joint on the left;

[0040] Figure 4 Schematic diagram of the joint connection input disk;

[0041] Figure 5 is a schematic diagram of the right cam plate assembly;

[0042] Figure 6 It is a schematic diagram of the left cam plate assembly;

[0043] Figure 7 This is a schematic diagram of the right output chassis assembly;

[0044] Figure 8 This is a schematic diagram of the left output chassis assembly;

[0045] Figure 9 Schematic diagram of the screw spring assembly;

[0046] Figure 10 Schematic diagram of the motor assembly;

[0047] Figure 11 It is the cross-sectional view of the right variable stiffness joint structure;

[0048] Figure 12 Schematic diagram of the transmission relationship between the left and right variable stiffness joints;

[0049] Reference numerals: 1, fixed waist belt, 2, right variable stiffness joint, 3, right thigh support rod, 4, right knee joint assembly, 5, right knee joint strap, 6, left variable stiffness joint, 7, left thigh support rod, 8, left knee joint assembly, 9, left knee joint strap;

[0050] 10-1, right joint connection input assembly, 10-2, left joint connection input assembly, 11, right cam plate assembly, 12, right output chassis assembly, 13-1, right screw spring assembly, 13-2, left screw spring assembly, 14-1, right motor assembly, 14-2, left motor assembly, 15-1, right protective shell, 15-2, left protective shell, 16, left cam plate assembly, 17, left output chassis assembly;

[0051] 18. Joint connection input plate, 19. Short rod, 20. Magnetic cylinder, 21. Circular groove, 22. Avoidance groove, 23. First deep groove ball bearing;

[0052] 24. Right cam disc, 25. Plane needle roller bearing, 26. Flange bearing, 27. Left cam disc;

[0053] 28. Right output chassis, 28-1. First connecting segment on the right side, 28-2. Second connecting segment on the right side, 29. First roller, 30. Second roller, 31. First retaining spring, 32. Left output chassis, 32-1. First connecting segment on the left side, 32-2. Second connecting segment on the left side, 33-1. Right rotary magnetic encoder, 33-2. Left rotary magnetic encoder, 34. Spindle, 35. Roller mounting hole, 36. Roller notch.

[0054] 37. Big gear, 38. Screw front bushing, 39. Screw front support, 40. Guide shaft connecting piece, 41. Trapezoidal screw, 42. Screw nut, 43. Guide shaft, 44. Heavy-duty spring, 45. Screw rear bushing, 46. Screw rear support, 47. Roller connector, 48. Spring sleeve;

[0055] 49. Pinion, 50. Motor front support, 51. Motor bushing, 52. Motor rear support, 53. Motor. DETAILED DESCRIPTION

[0056] The present invention is described in detail below with reference to 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 operating process. Obviously, the described embodiment is only an embodiment of a part of the present invention, not all embodiments, and the protection scope of the present invention is not limited to the following embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0057] In the drawings, components with identical structures are denoted by the same reference numerals, and components with similar structures or functions are denoted by similar reference numerals. The dimensions and thicknesses of each component shown in the drawings are arbitrary and are not limited by the present invention. To enhance clarity and illustrate the coordination between components, some components in the drawings are scaled, and the distances between components are increased or decreased.

[0058] In the description of the embodiments of the present application, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0059] Furthermore, the terms “first,” “second,” “third,” etc., are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0060] In the description of the embodiments of the present application, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0061] Example 1:

[0062] A quasi-passive variable stiffness energy storage assisted hip joint exoskeleton, such as Figure 1-12As shown, it includes a fixed waist belt 1, a right exoskeleton and a left exoskeleton, and the right exoskeleton and the left exoskeleton are symmetrically designed; wherein, the right exoskeleton includes a right variable stiffness joint 2, a right thigh support rod 3, a right knee joint assembly 4, and a right knee joint strap 5, and the upper and lower ends of the right thigh support rod 3 are respectively connected to the right variable stiffness joint 2 and the right knee joint assembly 4, and the right knee joint strap 5 is connected to the right knee joint assembly 4 through the strap reserved hole of the right knee joint assembly 4; similarly, the left exoskeleton includes a left variable stiffness joint 6, a left thigh support rod 7, a left knee joint assembly 8, and a left knee joint strap 9, and the upper and lower ends of the left thigh support rod 7 are respectively connected to the left variable stiffness joint 6 and the left knee joint assembly 8, and the left knee joint strap 9 is connected to the left knee joint assembly 8 through the strap reserved hole of the left knee joint assembly 8. In fact, in the embodiment of the present application, the right thigh support rod 3 and the left thigh support rod 7 have the same structure, the right knee joint assembly 4 and the left knee joint assembly 8 have the same structure, the right knee joint strap 5 and the left knee joint strap 9 have the same structure, and the right variable stiffness joint 2 and the left variable stiffness joint 6 have slightly different structures, but the two are basically symmetrically designed. In other embodiments, the right thigh support rod 3, right knee joint assembly 4, right knee joint strap 5, left thigh support rod 7, left knee joint assembly 8, and left knee joint strap 9 can also be adjusted to form an axisymmetric structure.

[0063] Take the right variable stiffness joint 2 as an example, Figure 2 As shown, the right variable stiffness joint 2 includes a right joint connection input component 10-1, a right cam disc component 11, a right output chassis component 12, a right screw spring component 13-1, and a right motor component 14-1. The upper end of the right joint connection input component 10-1 is provided with a belt reserved hole adapted to the fixed belt 1, and the lower end of the right joint connection input component 10-1 is provided with a joint connection input disc 18. The right cam disc component 11 is fixedly connected to the joint connection input disc 18. The two sides of the right output chassis component 12 are respectively connected to the right cam disc component 11 and the right screw spring component 13-1. The right screw spring component 13-1 is connected to the right cam disc component 11, and the right motor component 14-1 is installed. On the right output chassis 28, the output end of the right motor assembly 14-1 is connected to the right lead screw spring assembly 13-1, and the upper end of the right thigh support rod 3 is connected to the bottom end of the right output chassis assembly 12; when the wearer walks, the hip joint extends and drives the right thigh support rod 3 to move, causing the right output chassis assembly 12 to rotate relative to the right cam plate assembly 11, and the right lead screw spring assembly 13-1 connected to the right output chassis assembly 12 rotates accordingly and changes the spring compression of the right lead screw spring assembly 13-1; the output end of the right motor assembly 14-1 drives the lead screw nut 42 of the right lead screw spring assembly 13-1 to move and change the spring compression of the right lead screw spring assembly 13-1;

[0064] Similarly, if Figure 3As shown, the left variable stiffness joint 6 includes a left joint connection input component 10-2, a left cam disc component 16, a left output chassis component 17, a left screw spring component 13-2, and a left motor component 14-2. The upper end of the left joint connection input component 10-2 is provided with a belt pre-set hole adapted to the fixed belt 1, and the lower end of the left joint connection input component 10-2 is provided with a joint connection input disc 18. The left cam disc component 16 is fixedly connected to the joint connection input disc 18. The two sides of the left output chassis component 17 are respectively connected to the left cam disc component 16 and the left screw spring component 13-2. The left screw spring component 13-2 is connected to the left cam disc component 16. The left motor component 14-2 is installed On the left output chassis 32, the output end of the left motor assembly 14-2 is connected to the left screw spring assembly 13-2, and the upper end of the left thigh support rod 7 is connected to the bottom end of the left output chassis assembly 17; when the wearer walks, the hip joint extends and drives the left thigh support rod 7 to move, causing the left output chassis assembly 17 to rotate relative to the left cam plate assembly 16, and the left screw spring assembly 13-2 connected to the left output chassis assembly 17 rotates accordingly and changes the spring compression amount of the left screw spring assembly 13-2; the output end of the left motor assembly 14-2 drives the screw nut 42 of the left screw spring assembly 13-2 to move and changes the spring compression amount of the left screw spring assembly 13-2.

[0065] In this embodiment, the fixed waist belt 1 is made of cotton fabric and secured with Velcro at both ends. Inside the belt is a lightweight plastic sheet. The fixed waist belt 1 passes through the pre-recorded holes in the right variable stiffness joint 2 and the left variable stiffness joint 6, connecting the fixed waist belt 1 to the two exoskeletons.

[0066] In the embodiment of the present application, the right joint connection input assembly 10-1 has the same structure as the left joint connection input assembly 10-2, the right screw spring assembly 13-1 has the same structure as the left screw spring assembly 13-2, and the right motor assembly 14-1 has the same structure as the left motor assembly 14-2; the right cam disc assembly 11 is slightly different from the left cam disc assembly 16, and the two are symmetrically designed; the right output chassis assembly 12 is slightly different from the left output chassis assembly 17, and the two are symmetrically designed.

[0067] For the sake of simplicity, components with the same structure are described using the right variable stiffness joint as an example, and structures with symmetrical design are described using the left and right variable stiffness joints as examples.

[0068] The right joint connection input component 10-1 has the same structure as the left joint connection input component 10-2. Figure 4 As shown, the upper end of the right joint connection input component 10-1 is used to connect and fix the waist belt 1, and the lower end is provided with a joint connection input disk 18. The center of the joint connection input disk 18 is provided with a circular groove 21, and the center of the circular groove 21 is provided with a protruding short rod 19.

[0069] The right cam disc assembly 11 and the left cam disc assembly 16 are symmetrically designed. Figure 5 、 Figure 11 As shown, the right cam disc assembly 11 includes a right cam disc 24, a cam disc connecting screw, a flange bearing 26 and a plane needle roller bearing 25. The right cam disc 24 is fixedly connected to the joint connection input disc 18 by the cam disc connecting screw. A stepped through hole is provided in the center of the disc surface of the right cam disc 24. The flange bearing 26 and the plane needle roller bearing 25 are installed in the stepped through hole. The right cam disc assembly 11 and the right output chassis assembly 12 are connected by the plane needle roller bearing 25 and the flange bearing 26. The size of the stepped through hole near the side of the joint connection input disc 18 matches the size of the circular groove 21 in the center of the joint connection input disc 18. Arc-shaped notches are respectively provided on the upper and lower sides of the center of the disc surface of the right cam disc 24.

[0070] Similarly, if Figure 6 、 Figure 11 As shown, the left cam disc assembly 16 includes a left cam disc 27, a cam disc connecting screw, a flange bearing 26 and a plane needle roller bearing 25. The left cam disc 27 is fixedly connected to the joint connection input disc 18 by the cam disc connecting screw. A stepped through hole is provided in the center of the disc surface of the left cam disc 27. The flange bearing 26 and the plane needle roller bearing 25 are installed in the stepped through hole. The left cam disc assembly 16 and the left output chassis assembly 17 are connected by the plane needle roller bearing 25 and the flange bearing 26. The size of the stepped through hole near the side of the joint connection input disc 18 matches the size of the circular groove 21 in the center of the joint connection input disc 18. Arc-shaped notches are respectively provided on the upper and lower sides of the center of the disc surface of the left cam disc 27.

[0071] Arc-shaped notches are provided on the upper and lower sides of the center of the right cam disc 24. The upper arc-shaped notch is an arc with an opening angle of 120 degrees. The contour line of the lower arc-shaped notch is designed as a special function and is divided into two arc segments. The polar coordinates with the center of the right cam disc 24 as the origin are expressed as follows:

[0072]

[0073] Among them, θ represents the angular coordinate in polar coordinates, and r represents the radius coordinate in polar coordinates;

[0074] Arc-shaped notches are provided on the upper and lower sides of the center of the left cam disc 27. The upper arc-shaped notch is an arc with an opening angle of 120 degrees. The contour line of the lower arc-shaped notch is designed as a special function and is divided into two arc segments. The polar coordinates with the center of the left cam disc 27 as the origin are expressed as follows:

[0075]

[0076] Wherein, θ represents the angular coordinate in polar coordinates, and r represents the radius coordinate in polar coordinates.

[0077] Regarding the determination of the arc-shaped notch contour, this applicant studied the characteristics of human gait and, based on this, determined the core design requirements. Using the Archimedean spiral as a design template, they proposed multiple contour designs, conducted dynamic simulations, and conducted multiple experiments to determine the optimal solution. In fact, the right cam plate 24 and the left cam plate 27 are strictly symmetrical.

[0078] The right output chassis assembly 12 and the left output chassis assembly 17 are symmetrically designed. Figure 7 、 Figure 11 As shown, the right output chassis assembly 12 includes a right output chassis 28, a right first connecting section 28-1, a right second connecting section 28-2, a first roller 29, a second roller 30, and a first retaining spring 31. The right first connecting section 28-1 and the right second connecting section 28-2 extend from the upper end and the lower end of the right output chassis 28 respectively. The right thigh support rod 3 is connected to the right second connecting section 28-2. A stepped main shaft 34 adapted to the right cam disc assembly 11 is provided at the center of the right output chassis 28; roller mounting holes 35 and roller slots 36 are provided on both sides of the main shaft 34 respectively. The first roller 29 is installed on the right output chassis 28 through the roller mounting hole 35, and the side of the first roller 29 contacts the right cam disc assembly 11. The upper contour line of the upper arc-shaped slot on the wheel disc 24, the size of the roller slot 36 is adapted to the second roller 30, and the second roller 30 is installed on the right screw spring assembly 13-1; the main shaft 34 passes through the plane needle bearing 25 and the flange bearing 26 in the stepped through hole in the center of the disk surface of the right cam disc assembly 11 in sequence, and a retaining spring groove is provided at the top of the main shaft 34. The first retaining spring 31 is installed in the retaining spring groove and presses the inner ring of the flange bearing 26 to limit the axial position of the right cam disc assembly 11. The circular groove 21 in the center of the joint connection input disc 18 is adapted to the outer ring of the flange bearing 26. The main shaft 34 is a hollow sleeve, and the short rod 19 is inserted into the main shaft 34. The short rod 19 and the main shaft 34 are matched and connected. Specifically, the first deep groove ball bearing 23 is used to connect the short rod 19 and the main shaft 34, thereby realizing the mating connection between the joint connection input connecting plate and the right output chassis 28; the roller mounting hole 35 is a threaded hole, and the cam of the first roller 29 contacts the upper contour line of the upper arc-shaped slot. The bottom of the first roller 29 is provided with a thread adapted to the roller mounting hole 35, so that it is screwed to the right output chassis 28.

[0079] Similarly, if Figure 8 、 Figure 11As shown, the left output chassis assembly 17 includes a left output chassis 32, a left first connecting section 32-1, a left second connecting section 32-2, a first roller 29, a second roller 30, and a first retaining spring 31. The left first connecting section 32-1 and the left second connecting section 32-2 extend from the upper end and the lower end of the left output chassis 32 respectively. The left thigh support rod 7 is connected to the left second connecting section 32-2. A stepped main shaft 34 adapted to the left cam disc assembly 16 is provided at the center of the left output chassis 32; roller mounting holes 35 and roller slots 36 are provided on both sides of the main shaft 34, the first roller 29 is mounted on the left output chassis 32 through the roller mounting hole 35, and the side surface of the first roller 29 contacts the upper contour line of the upper arc-shaped slot on the left cam disc 27, the size of the roller slot 36 is adapted to the second roller 30, and the second roller 30 is mounted on the left screw spring assembly 13-2; the main shaft 34 is provided according to The flat needle roller bearing 25 and the flange bearing 26 pass through the stepped through hole in the center of the left cam disc assembly 16. A retaining ring groove is provided at the top of the main shaft 34. The first retaining ring 31 is installed in the retaining ring groove and presses the inner ring of the flange bearing 26 to limit the axial position of the left cam disc assembly 16. The circular groove 21 in the center of the joint connection input disc 18 is adapted to the outer ring of the flange bearing 26. The main shaft 34 is a hollow sleeve. The short rod 19 is inserted into the main shaft 34. The short rod 19 and the main shaft 34 are matched. Specifically, the first deep groove ball bearing 23 is used to connect the short rod 19 and the main shaft 34, thereby realizing the matching connection between the joint connection input connection disc and the left output chassis 32; the roller mounting hole 35 is a threaded hole, and the cam of the first roller 29 contacts the upper contour line of the upper arc-shaped notch. The bottom of the first roller 29 is provided with a thread adapted to the roller mounting hole 35, so that it is screwed to the left output chassis 32.

[0080] The first roller 29 is a fixed cam roller, and the second roller 30 is a moving cam roller. Both rollers can move along the contour of the arc-shaped notch on the cam disc. The cam fixed roller and the moving cam roller are positioned symmetrically, balancing the forces on the cam disc and providing support and stability for the cam disc assembly.

[0081] The cam disc is fixedly connected to the joint connection input disc 18 via a cam disc connecting screw, and both are fixed together with the waist belt to the wearer's hip joint. The cam disc assembly is connected to the output chassis assembly via a plane needle bearing and a flange bearing, and the cam disc assembly is limited by a retaining spring. The two cam rollers, main shaft, and first retaining spring of the left output chassis assembly 17 are the same as those of the right output chassis assembly 12, while the left output chassis 32 and the right output chassis 28 are symmetrically designed. Among them, the right thigh support rod 3 and the left thigh support rod 7 are symmetrically designed. The right second connecting section 28-2 and the left second connecting section 32-2 are both oriented downward, and the left side protruding platforms of the two (i.e., the right first connecting section 28-1 and the left first connecting section 32-1) are offset in different directions.

[0082] The right screw spring assembly 13-1 has the same structure as the left screw spring assembly 13-2. Figure 9 、 Figure 11 As shown, the right screw spring assembly 13-1 includes a large gear 37, a screw front shaft sleeve 38, a screw front support 39, a guide shaft connecting piece 40, a trapezoidal screw 41, a screw nut 42, a guide shaft 43, a heavy-duty spring 44, a screw rear shaft sleeve 45, a screw rear support 46, a roller connector 47, and a spring sleeve 48. The large gear 37 is connected to the screw front shaft sleeve 38 through a retaining spring and a flat key, the screw front shaft sleeve 38 is connected to the screw front support 39 through a deep groove ball bearing, the screw rear shaft sleeve 45 is connected to the screw rear support 46 through a deep groove ball bearing, the screw front support 39 and the screw rear support 46 are respectively installed in the right first connecting section 28-1 and the right second connecting section 28-2. One end of the trapezoidal screw 41 passes through the screw front shaft sleeve 38 and is connected to the screw front shaft sleeve 38 using a flat key. The other end of the trapezoidal screw 41 passes through the screw rear shaft sleeve 45 and is connected to the screw rear shaft sleeve 45 using a flat key. The spring sleeve 48 is connected to the right cam disc 24 by screws. The heavy-load spring 44 is arranged in the accommodation space formed between the spring sleeve 48 and the right cam disc 24. The screw front support 39 and the screw rear support 46 are arranged outside the accommodation space formed between the spring sleeve 48 and the right cam disc 24.

[0083] There is a large through hole in the middle of the heavy-load spring 44, which is sleeved on the trapezoidal screw 41. The two ends of the heavy-load spring 44 are respectively connected to the screw nut 42 and the roller connector 47. The screw nut 42 is sleeved on the trapezoidal screw 41 and is threaded with the trapezoidal screw 41. The roller connector 47 is sleeved on the trapezoidal screw 41. The movement of the screw nut 42 and the roller connector 47 on the trapezoidal screw 41 will cause the expansion and contraction amount of the heavy-load spring 44 to change. The second roller 30 is connected to the roller connector 47. After passing through the roller slot 36, the second roller 30 cooperates with the right output chassis 28. The side of the second roller 30 contacts the lower contour line of the lower arc-shaped slot on the right cam disc 24. Specifically, one end of the roller connector 47 is provided with a copper sleeve, which is sleeved on the trapezoidal screw through the copper sleeve. The other end of the roller connector 47 is provided with a threaded hole. After the cam of the second roller 30 passes through the roller slot 36, it contacts the lower contour line of the lower arc-shaped slot on the cam disc. The bottom of the second roller 30 is provided with a thread, so that it is screwed with the roller connector 47. The copper sleeve is sleeved on the lower end of the cam moving roller to play a positioning and supporting role.

[0084] The lead screw nut 42 is also provided with guide holes for guide shafts 43. There are two guide shafts 43, which are arranged parallel to the lead screw 41. The guide shaft connecting piece 40 is screwed to the front support of the lead screw. One end of the guide shaft 43 is connected to the guide shaft connecting piece 40, and the other end passes through the guide hole and connects to the spring sleeve 48, thus securing the two ends. The rotation of the large gear 37 drives the lead screw 41, and the lead screw nut 42 moves along the lead screw 41 with the rotation of the lead screw 41. The arrangement of the guide shafts 43 ensures that the lead screw nut 42 does not rotate as it moves forward and backward along the lead screw 41, but only moves linearly.

[0085] The spring sleeve 48 is made of nylon and features an observation slot on its top and a pre-recorded hole on its left end for securing the guide shaft 43. The spring sleeve 48 is secured to the output chassis (left output chassis 32, right output chassis 28) with screws. The inner surface of the spring sleeve 48 is a smooth cylindrical surface, with an inner diameter that is 1.5 mm larger than the outer diameter of the heavy-duty spring 44 when coaxial, to limit the position of the heavy-duty spring 44. The surface is fully greased to ensure proper compression of the heavy-duty spring 44 within the spring sleeve 48.

[0086] The right motor assembly 14-1 has the same structure as the left motor assembly 14-2. Figure 10 、 Figure 11 As shown, the right motor assembly 14-1 includes a pinion 49, a motor front support 50, a motor sleeve 51, a motor rear support 52, and a motor 53. The pinion 49 is meshed with the large gear 37. The pinion 49 is connected to the motor sleeve 51 through a retaining spring and a flat key. The motor sleeve 51 is connected to the motor front support 50 through a deep groove ball bearing. The motor 53 is installed on the motor rear support 52 by screws. The motor front support 50 and the motor rear support 52 are installed in the right first connecting section 28-1. The output shaft of the motor 53 penetrates into the motor sleeve 51 and is connected to the motor sleeve 51. The motor output shaft drives the pinion 49 to rotate, and then drives the large gear 37 meshed with it to rotate, thereby changing the position of the screw nut 42 and changing the compression amount of the heavy-load spring 44.

[0087] The transmission relationship diagram of the left and right variable stiffness joints is as follows: Figure 12As shown. When the wearer walks while wearing the exoskeleton and the hip joint extends, the moving lower limbs drive the knee joint assembly and thigh support rod to move, causing the cam rollers of the output chassis and the lead screw assembly to rotate relative to the fixed waist belt and cam disc assembly. The cam moving rollers will move along the contour of the specially designed cam disc, thereby compressing the heavy-duty spring to store energy, which is released when the hip joint flexes and steps forward to provide walking assistance. In addition, the position of the lead screw nut can be adjusted by the motor to change the pre-compression of the heavy-duty spring, thereby increasing the stiffness of the entire variable-stiffness joint. This allows the exoskeleton to adjust the assistive stiffness according to the wearer's height, weight, and walking speed.

[0088] The right variable stiffness joint 2 also includes a right protective shell 15-1, and the left variable stiffness joint 6 also includes a left protective shell 15-2. The right protective shell 15-1 and the left protective shell 15-2 have the same structure. The right protective shell 15-1 is installed on the right first connecting section 28-1, and the large gear 37, the small gear 49, the front support of the screw 39 and the front support of the motor 50 are all arranged in the accommodating space formed between the right protective shell 15-1 and the right first connecting section 28-1. In the embodiment of the present application, the protective shell (the right protective shell 15-1 and the left protective shell 15-2) are lightweight and thin shell parts made using a 3D printing process. They are connected to the protruding parts (the right first connecting section 28-1 and the left first connecting section 32-1) of the output chassis (the right output chassis 28 and the left output chassis 32) by screws, shielding and protecting the large gear 37 and the small gear 49 to avoid contamination by dust and impurities.

[0089] The right joint connection input component 10-1 has the same structure as the left joint connection input component 10-2. Figure 4 As shown, escape grooves 22 are provided on the upper and lower sides of the center of the articulation input disc 18 of the right articulation input assembly 10-1, corresponding to the two arcuate notches of the right cam disc 24. These avoid the movement of the two rollers along the two arcuate notches of the right cam disc 24. In practice, since the upper arcuate notch of the right cam disc 24 is a standard design, the escape groove 22 corresponding to the upper arcuate notch can be omitted. Only the escape groove 22 corresponding to the lower arcuate notch of the right cam disc 24 is provided on the lower side of the center of the articulation input disc 18. Similarly, the articulation input disc 18 of the left articulation input assembly 10-2 is also provided with an escape groove 22. The shape of the escape groove 22 is consistent with the shape of the arcuate notch on the cam disc.

[0090] In the right joint connection input component 10-1, as Figure 4As shown, the short rod 19 is a hollow structure, and a magnetic cylinder 20 is provided inside the short rod 19. The magnetic cylinder 20 is interference-fitted with the short rod 19. The right variable stiffness joint 2 also includes a right rotary magnetic encoder 33-1, which is mounted on the right cam disc assembly 11. The model of the right rotary magnetic encoder 33-1 matches the magnetic cylinder 20 to detect the rotation angle. The right rotary magnetic encoder 33-1 can be fixed to the back of the right cam disc 24 (the disc surface near the right screw spring assembly 13-1) by means of screws or other structures. Similarly, the left variable stiffness joint 6 also includes a left rotary magnetic encoder 33-2, which is mounted on the left cam disc assembly 16. The left rotary magnetic encoder 33-2 matches the magnetic cylinder 20 inside the short rod 19 on the left joint connection input assembly 10-2.

[0091] The right knee joint assembly 4 is identical in structure to the left knee joint assembly 8. It comprises an upper knee joint and a lower knee joint, which are rotatably connected. The upper knee joint is connected to the right thigh support rod 3, while the lower knee joint is provided with a pre-reserved hole for the right knee strap 5. The knee strap passes through the pre-reserved hole in the knee joint component, maintaining the knee joint's rotational center of alignment and securing it to the calf.

[0092] In this embodiment, the upper ends of the thigh support rods are screwed to the left and right output chassis assemblies of the left and right variable stiffness joints, while the lower ends are screwed to the knee joint assembly. The knee joint assembly is made of plastic, the joint connection input plate 18 is made of nylon plastic, the spring sleeve 48 is made of resin, the protective shells (right protective shell 15-1 and left protective shell 15-2) are lightweight, thin shells made of ASA plastic, and the thigh support rods (right thigh support rod 3 and left thigh support rod 7) are made of carbon fiber sheet material. The lightweight material selection of these components contributes to the overall lightweight nature of the exoskeleton.

[0093] The right variable stiffness joint 2 and the left variable stiffness joint 6 are designed symmetrically, and the variable stiffness joints on both sides are designed in upper and lower layers. Based on the left and right output chassis, Figure 12 As shown, the upper layer comprises the lead screw spring assembly, spring housing, motor assembly, and protective housing. The lower layer comprises the input joint connecting the input assembly and the left and right cam disc assemblies. The upper and lower layers are connected by the cam rollers via the grooves under the left and right cam discs, ensuring a complete transmission relationship. The upper and lower structural design of the left and right variable stiffness joints fully utilizes space and reduces joint volume.

[0094] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A quasi-passive variable stiffness energy storage assisted hip joint exoskeleton, characterized in that: It comprises a fixed waist belt (1), a right exoskeleton and a left exoskeleton, wherein the right exoskeleton and the left exoskeleton are symmetrically designed; The right exoskeleton comprises a right variable stiffness joint (2), a right thigh support rod (3), a right knee joint assembly (4), and a right knee joint strap (5); the upper and lower ends of the right thigh support rod (3) are respectively connected to the right variable stiffness joint (2) and the right knee joint assembly (4); and the right knee joint strap (5) is connected to the right knee joint assembly (4) through a strap reserved hole of the right knee joint assembly (4); The right variable stiffness joint (2) comprises a right joint connection input component (10-1), a right cam disc component (11), a right output chassis component (12), a right screw spring component (13-1), and a right motor component (14-1). The upper end of the right joint connection input component (10-1) is provided with a waist belt reserved hole adapted to the fixed waist belt (1). The lower end of the right joint connection input component (10-1) is provided with a joint connection input disc (18). The right cam disc component (11) and the joint connection input disc (14-1) are connected to each other. 18) are fixedly connected, the two sides of the right output chassis assembly (12) are respectively connected to the right cam disc assembly (11) and the right screw spring assembly (13-1), the right screw spring assembly (13-1) is connected to the right cam disc assembly (11), the right motor assembly (14-1) is installed on the right output chassis (28), the output end of the right motor assembly (14-1) is connected to the right screw spring assembly (13-1), and the upper end of the right thigh support rod (3) is connected to the bottom end of the right output chassis assembly (12); When the wearer is walking, the hip joint extends to drive the right thigh support rod (3) to move, causing the right output chassis assembly (12) to rotate relative to the right cam plate assembly (11), and the right screw spring assembly (13-1) connected to the right output chassis assembly (12) rotates accordingly and changes the spring compression amount of the right screw spring assembly (13-1); the output end of the right motor assembly (14-1) drives the screw nut (42) of the right screw spring assembly (13-1) to move and changes the spring compression amount of the right screw spring assembly (13-1); The left exoskeleton comprises a left variable stiffness joint (6), a left thigh support rod (7), a left knee joint assembly (8), and a left knee joint strap (9), wherein the upper and lower ends of the left thigh support rod (7) are respectively connected to the left variable stiffness joint (6) and the left knee joint assembly (8), and the left knee joint strap (9) is connected to the left knee joint assembly (8) through a strap reserved hole of the left knee joint assembly (8); The left variable stiffness joint (6) comprises a left joint connection input component (10-2), a left cam disc component (16), a left output chassis component (17), a left screw spring component (13-2), and a left motor component (14-2). The upper end of the left joint connection input component (10-2) is provided with a waist belt reserved hole adapted to the fixed waist belt (1). The lower end of the left joint connection input component (10-2) is provided with a joint connection input disc (18). The left cam disc component (16) and the joint connection input disc (18) are connected to each other. 18) are fixedly connected, the two sides of the left output chassis assembly (17) are respectively connected to the left cam disc assembly (16) and the left screw spring assembly (13-2), the left screw spring assembly (13-2) is connected to the left cam disc assembly (16), the left motor assembly (14-2) is installed on the left output chassis (32), the output end of the left motor assembly (14-2) is connected to the left screw spring assembly (13-2), and the upper end of the left thigh support rod (7) is connected to the bottom end of the left output chassis assembly (17); When the wearer is walking, the hip joint extends to drive the left thigh support rod (7) to move, causing the left output chassis assembly (17) to rotate relative to the left cam plate assembly (16), and the left screw spring assembly (13-2) connected to the left output chassis assembly (17) rotates accordingly and changes the spring compression amount of the left screw spring assembly (13-2); the output end of the left motor assembly (14-2) drives the screw nut (42) of the left screw spring assembly (13-2) to move and changes the spring compression amount of the left screw spring assembly (13-2); The right joint connection input assembly (10-1) and the left joint connection input assembly (10-2) have the same structure. A circular groove (21) is provided at the center of the joint connection input disk (18). A protruding short rod (19) is provided at the center of the circular groove (21). The short rod (19) is a hollow structure. A magnetic cylinder (20) is provided in the short rod (19). The magnetic cylinder (20) and the short rod (19) are interference fit. The right variable stiffness joint (2) further includes a right rotary magnetic encoder (33-1), and the left variable stiffness joint (6) further includes a left rotary magnetic encoder (33-2), the right rotary magnetic encoder (33-1) being mounted on the right cam disc assembly (11), and the left rotary magnetic encoder (33-2) being mounted on the left cam disc assembly (16); The right cam disc assembly (11) and the left cam disc assembly (16) are symmetrically designed. The right cam disc assembly (11) includes a right cam disc (24), a cam disc connecting screw, a flange bearing (26) and a plane needle roller bearing (25). The right cam disc (24) is fixedly connected to the joint connection input disc (18) through the cam disc connecting screw. A stepped through hole is provided at the center of the disc surface of the right cam disc (24). The flange bearing (26) and the plane needle roller bearing (25) are installed in the stepped through hole. The right cam disc assembly (11) and the right output chassis assembly (12) are matched with each other through the plane needle roller bearing (25) and the flange bearing (26). The size of the stepped through hole near the side of the joint connection input disc (18) matches the size of the circular groove (21) in the center of the joint connection input disc (18). The upper and lower sides of the center of the disc surface of the right cam disc (24) are respectively provided with arc-shaped notches. The left cam disc assembly (16) includes a left cam disc (27), a cam disc connecting screw, a flange bearing (26) and a plane needle roller bearing (25), wherein the left cam disc (27) is fixedly connected to the joint connection input disc (18) through the cam disc connecting screw, a stepped through hole is provided at the center of the disc surface of the left cam disc (27), and the flange bearing (26) and the plane needle roller bearing (25) are installed in the stepped through hole, and the left cam disc assembly (16) and the left output chassis assembly (17) are matched with each other through the plane needle roller bearing (25) and the flange bearing (26), and the size of the stepped through hole near the side of the joint connection input disc (18) matches the size of the circular groove (21) in the center of the joint connection input disc (18), and arc-shaped notches are respectively provided on the upper and lower sides of the disc surface center of the left cam disc (27).

2. A quasi-passive variable stiffness energy storage assisted hip joint exoskeleton according to claim 1, characterized in that: The joint connection input disc (18) is provided with avoidance grooves (22) on the upper and lower sides of the disc center, which are adapted to the two arc-shaped notches of the right cam disc (24); or, A relief groove (22) adapted to the arc-shaped notch on the lower side of the right cam disc (24) is provided on the lower side of the center of the disc surface of the joint connection input disc (18).

3. The quasi-passive variable stiffness energy storage assisted hip joint exoskeleton according to claim 1, characterized in that: The right output chassis assembly (12) and the left output chassis assembly (17) are symmetrically designed. The right output chassis assembly (12) includes a right output chassis (28), a right first connecting section (28-1), a right second connecting section (28-2), a first roller (29), a second roller (30), and a first retaining spring (31). The right first connecting section (28-1) and the right second connecting section (28-2) extend from the upper end and the lower end of the right output chassis (28), respectively. The right thigh support rod (3) is connected to the right second connecting section (28-2). A stepped main shaft (34) adapted to the right cam disc assembly (11) is provided at the center of the right output chassis (28); roller mounting holes (35) and roller slots (36) are provided on both sides of the main shaft (34). The first roller (29) is mounted on the right output chassis (28) through the roller mounting hole (35), and the first The side surface of the roller (29) contacts the upper contour line of the upper arc-shaped notch on the right cam disc (24), and the size of the roller notch (36) is adapted to the second roller (30), and the second roller (30) is installed on the right screw spring assembly (13-1); the main shaft (34) passes through the plane needle bearing (25) and the flange bearing (26) in the stepped through hole in the center of the disk surface of the right cam disc assembly (11) in sequence, and the top of the main shaft (34) is provided with a retaining spring groove, and the first retaining spring (31) is installed in the retaining spring groove and presses the inner ring of the flange bearing (26) to limit the axial position of the right cam disc assembly (11), and the circular groove (21) in the center of the joint connection input disc (18) is adapted to the outer ring of the flange bearing (26), and the main shaft (34) is a hollow sleeve, and the short rod (19) is inserted into the main shaft (34), and the short rod (19) and the main shaft (34) are matched and connected; The left output chassis assembly (17) includes a left output chassis (32), a left first connecting section (32-1), a left second connecting section (32-2), a first roller (29), a second roller (30), and a first retaining spring (31). The left first connecting section (32-1) and the left second connecting section (32-2) extend from the upper end and the lower end of the left output chassis (32), respectively. The left thigh support rod (7) is connected to the left second connecting section (32-2). A stepped main shaft (34) adapted to the left cam disc assembly (16) is provided at the center of the left output chassis (32); roller mounting holes (35) and roller slots (36) are provided on both sides of the main shaft (34). The first roller (29) is mounted on the left output chassis (32) through the roller mounting hole (35), and the side surface of the first roller (29) contacts the left cam disc ( 27), the size of the roller slot (36) is adapted to the second roller (30), and the second roller (30) is installed on the left screw spring assembly (13-2); the main shaft (34) passes through the plane needle bearing (25) and the flange bearing (26) in the stepped through hole in the center of the left cam disc assembly (16) in sequence, and the top of the main shaft (34) is provided with a retaining spring groove, and the first retaining spring (31) is installed in the retaining spring groove and presses the inner ring of the flange bearing (26) to limit the axial position of the left cam disc assembly (16), and the circular groove (21) in the center of the joint connection input disc (18) is adapted to the outer ring of the flange bearing (26), and the main shaft (34) is a hollow sleeve, and the short rod (19) is inserted into the main shaft (34), and the short rod (19) and the main shaft (34) are matched and connected.

4. A quasi-passive variable stiffness energy storage assisted hip joint exoskeleton according to claim 3, characterized in that: The right screw spring assembly (13-1) has the same structure as the left screw spring assembly (13-2). The right screw spring assembly (13-1) includes a large gear (37), a screw front shaft sleeve (38), a screw front support (39), a guide shaft connecting piece (40), a trapezoidal screw (41), a screw nut (42), a guide shaft (43), a heavy-load spring (44), a screw rear shaft sleeve (45), a screw rear support (46), a roller connector (47), and a spring sleeve (48). The large gear (37) is connected to the screw front shaft sleeve (38), the screw front shaft sleeve (38) is connected to the screw front support (39), the screw rear shaft sleeve (45) is connected to the screw rear support (46), and the screw front The support (39) and the screw rear support (46) are respectively installed on the right first connecting section (28-1) and the right second connecting section (28-2), one end of the trapezoidal screw (41) penetrates the screw front shaft sleeve (38) and is connected to the screw front shaft sleeve (38), the other end of the trapezoidal screw (41) penetrates the screw rear shaft sleeve (45) and is connected to the screw rear shaft sleeve (45), the spring sleeve (48) is connected to the right cam disc (24) by a screw, the heavy-load spring (44) is arranged in the accommodating space formed between the spring sleeve (48) and the right cam disc (24), and the screw front support (39) and the screw rear support (46) are arranged outside the accommodating space formed between the spring sleeve (48) and the right cam disc (24); The heavy-load spring (44) is sleeved on the trapezoidal lead screw (41), and the two ends of the heavy-load spring (44) are respectively connected to the lead screw nut (42) and the roller connector (47), the lead screw nut (42) is sleeved on the trapezoidal lead screw (41) and is threadedly engaged with the trapezoidal lead screw (41), the roller connector (47) is sleeved on the trapezoidal lead screw (41), the second roller (30) is connected to the roller connector (47), the second roller (30) passes through the roller slot (36) and is engaged with the right output chassis (28), and the side surface of the second roller (30) contacts the lower side contour line of the lower arc-shaped slot on the right cam plate (24); The lead screw nut (42) is also provided with a guide hole adapted to the guide shaft (43), one end of the guide shaft (43) is connected to the guide shaft connecting piece (40), and the other end is connected to the spring sleeve (48) after passing through the guide hole. The guide shaft connecting piece (40) is installed on the front support of the lead screw. The rotation of the large gear (37) drives the trapezoidal lead screw (41) to rotate, and the lead screw nut (42) moves along the trapezoidal lead screw (41) as the trapezoidal lead screw (41) rotates.

5. The quasi-passive variable stiffness energy storage assisted hip joint exoskeleton according to claim 4, characterized in that: The right motor assembly (14-1) has the same structure as the left motor assembly (14-2). The right motor assembly (14-1) comprises a pinion (49), a motor front support (50), a motor shaft sleeve (51), a motor rear support (52), and a motor (53). The pinion (49) is meshed with the large gear (37). The pinion (49) is cooperatively connected to the motor shaft sleeve (51). The motor shaft sleeve (51) is cooperatively connected to the motor front support (50). The motor (53) is mounted on the motor rear support (52). The motor front support (50) and the motor rear support (52) are mounted on the right first connecting section (28-1). The output shaft of the motor (53) penetrates the motor shaft sleeve (51) and is cooperatively connected to the motor shaft sleeve (51). The motor output shaft drives the pinion (49) to rotate.

6. The quasi-passive variable stiffness energy storage assisted hip joint exoskeleton according to claim 5, characterized in that: The right variable stiffness joint (2) further comprises a right protective shell (15-1), and the left variable stiffness joint (6) further comprises a left protective shell (15-2). The right protective shell (15-1) and the left protective shell (15-2) have the same structure. The right protective shell (15-1) is mounted on the right first connecting section (28-1), and the large gear (37), the small gear (49), the lead screw front support (39) and the motor front support (50) are all arranged in an accommodating space formed between the right protective shell (15-1) and the right first connecting section (28-1).

7. The quasi-passive variable stiffness energy storage assisted hip joint exoskeleton according to claim 1, characterized in that: The right knee joint assembly (4) has the same structure as the left knee joint assembly (8), and the right knee joint assembly (4) comprises an upper knee joint and a lower knee joint, the upper knee joint and the lower knee joint are rotatably connected, the upper knee joint is connected to the right thigh support rod (3), and the lower knee joint is provided with a strap reserved hole adapted to the right knee joint strap (5).

8. The quasi-passive variable stiffness energy storage assisted hip joint exoskeleton according to claim 1, characterized in that: The center of the right cam disc (24) is provided with arc-shaped notches on the upper and lower sides, respectively. The arc-shaped notch on the upper side is an arc with an opening angle of 120 degrees. The contour line of the arc-shaped notch on the lower side is designed as a special function and is divided into two arc segments. The polar coordinates with the center of the right cam disc (24) as the origin are expressed as follows: in, represents the angular coordinates in polar coordinates, Represents the radius coordinate in polar coordinates; The upper and lower sides of the center of the left cam disc (27) are respectively provided with arc-shaped notches. The upper arc-shaped notch is an arc with an opening angle of 120 degrees. The contour line of the lower arc-shaped notch is designed as a special function and is divided into two arcs in total. It is expressed in the following form in polar coordinates with the center of the left cam disc (27) as the origin: in, represents the angular coordinates in polar coordinates, Represents the radius coordinate in polar coordinates.

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