Variable-stiffness knee joint exoskeleton structure

Abstract

The variable-rigidity knee joint exoskeleton structure comprises a thigh assembly, a variable-rigidity knee joint assembly and a shank assembly which are connected from top to bottom, the variable-rigidity knee joint assembly comprises a baffle, a spring guide assembly, a rotating plate and a limiting sleeve, and the baffle is in an inverted L shape and comprises a supporting part and a limiting part which are fixedly connected; the thigh assembly is fixedly connected with the upper surface of the supporting part of the baffle, the shank assembly is fixedly connected with the rotating plate, the rotating plate is hinged to one end of the supporting part, the spring guide assembly is arranged between the rotating plate and the supporting part, and the limiting part is used for limiting the rotating limit of the rotating plate and supporting the rotating plate when the rotating plate reaches the rotating limit. A composite variable stiffness scheme is designed, through a separated structure, the structures are jointed during standing to achieve rigid supporting, the structures are separated during leg lifting swing to achieve free movement of joints, and mechanical movement interference is eliminated.

Description

Technical Field

[0001] This invention relates to rehabilitation aids, specifically to a variable stiffness knee exoskeleton structure. Background Technology

[0002] With the number and proportion of the elderly population increasing year by year and the growth rate accelerating, the decline or even loss of walking, the most basic form of human movement, as people age can have a significant impact on their daily lives. Therefore, research on lower limb exoskeletons has attracted much attention, becoming a crucial factor in solving the mobility problems of people with limited mobility and improving their quality of life. Most existing traditional exoskeletons are designed around rigid joints. Although they offer good stability, they rarely consider the need for flexibility, which directly leads to poor device comfort. Active exoskeletons, on the other hand, are often bulky, require complex control algorithms, and consequently have high manufacturing and maintenance costs. Summary of the Invention

[0003] Purpose of the invention: To address the above-mentioned shortcomings, this invention provides a variable stiffness knee exoskeleton robot with a simple structure and good comfort.

[0004] Technical Solution: To solve the above problems, the present invention adopts a variable stiffness knee exoskeleton structure, including a thigh assembly, a variable stiffness knee joint assembly, and a lower leg assembly connected from top to bottom. The variable stiffness knee joint assembly includes a baffle, a spring guide assembly, a rotating plate, and a limiting sleeve. The baffle is inverted L-shaped and includes a fixedly connected support part and a limiting part. The thigh assembly is fixedly connected to the upper surface of the support part of the baffle, and the lower leg assembly is fixedly connected to the rotating plate. The rotating plate is hinged to one end of the support part. A spring guide assembly is provided between the rotating plate and the support part. The limiting part is used to limit the rotation limit of the rotating plate and support the rotating plate when the rotating plate reaches the rotation limit.

[0005] Furthermore, an abutment step is provided between the support part and the limiting part of the baffle, and an abutment plate is provided on the rotating plate. When the extension directions of the thigh assembly and the calf assembly are parallel, the abutment plate of the rotating plate abuts against the abutment step of the baffle. The abutment plate applies a force to the abutment step that is parallel to the extension directions of the thigh assembly and the calf assembly, and the calf assembly supports the thigh assembly.

[0006] Furthermore, the spring guide assembly includes a spring guide rod base, a first spring, a spring guide rod, and a limiting sleeve. The spring guide rod base is fixedly connected to the lower surface of the support portion of the baffle. The rotating plate is provided with a through hole. One end of the spring guide rod is fixedly connected to the support portion of the baffle, and the other end passes through the first spring and then through the through hole of the rotating plate. The limiting sleeve is fixed to the end of the spring guide rod to limit the rotation angle of the rotating plate.

[0007] Furthermore, a foot assembly is connected to the bottom of the lower leg assembly. The lower leg assembly includes a lower support and a connecting plate. One end of the lower support is fixedly connected to the rotating plate, and the other end is connected to the foot assembly. One end of the connecting plate is connected to the foot assembly to fix the user's lower leg.

[0008] Furthermore, the foot assembly includes a housing that is hinged to the lower leg assembly, a second spring and a slider disposed inside the housing. One end of the second spring is fixedly connected to the inside of the housing, and the other end is fixedly connected to the slider. A first connecting plate is hinged to the slider. One end of the first connecting plate, the lower end of the lower support, and one end of the second connecting plate are hinged to each other. The other end of the second connecting plate is hinged to the housing. One end of the connecting plate is fixedly connected to the housing. The slider moves inside the housing along the direction perpendicular to the extension of the connecting plate, thereby moving the lower end of the lower support.

[0009] Furthermore, the housing is provided with a limiting hole, and a limiting pin is provided in the limiting hole. The limiting pin is used to limit the rotation of the lower support.

[0010] Furthermore, the foot assembly also includes an elastic pull cord, one end of which is fixedly connected to the slider and the other end of which is fixedly connected to the middle of the lower support.

[0011] Furthermore, a limiting baffle is provided inside the housing to limit the movement distance of the slider.

[0012] Furthermore, the calf assembly also includes a calf buckle and a calf strap. The calf buckle fixes the calf strap to the connecting plate, and the calf strap is worn on the user's calf. The calf buckle includes a first hook and a first buckle base. The first hook engages with the calf strap slot. The first buckle base is connected to the connecting plate by screws through screw holes.

[0013] Furthermore, the thigh assembly includes an upper support, a thigh buckle, and a thigh strap. The bottom end of the upper support is fixedly connected to the upper surface of the support portion of the baffle. The thigh buckle fixes the thigh strap to the upper support. The thigh strap is worn on the user's thigh. The thigh buckle includes a second hook and a second buckle base. The second hook engages with the thigh strap's slot. The second buckle base is connected to the upper support by a screw through a screw hole.

[0014] Beneficial Effects: Compared with existing technologies, the significant advantage of this invention lies in its composite variable stiffness design. Through a separable structure, the structure is joined to achieve rigid support when standing, and separated to allow free joint movement when the leg is raised and swaying, eliminating mechanical motion interference. The multifunctional intelligent exoskeleton robot provided by this invention has a reasonable structure, is lightweight, can be quickly assembled and disassembled, has few parts, is simple to manufacture, and has high reliability. Attached Figure Description

[0015] Figure 1This is a schematic diagram of the overall structure of the exoskeleton in this invention.

[0016] Figure 2 This is a schematic diagram of the thigh buckle structure in this invention.

[0017] Figure 3 This is a schematic diagram of the thigh strap structure in this invention.

[0018] Figure 4 This is a schematic diagram of the variable stiffness knee joint assembly in this invention.

[0019] Figure 5 This is a schematic diagram of the spring guide assembly in this invention.

[0020] Figure 6 This is a schematic diagram of the lower leg buckle in this invention.

[0021] Figure 7 This is a schematic diagram of the calf strap structure in this invention.

[0022] Figure 8 This is a schematic diagram of the foot component in this invention.

[0023] Figure 9 This is a schematic diagram of the exoskeleton structure when the elastic rope is tightened.

[0024] In the diagram: 1. Upper support; 2. Thigh buckle; 3. Thigh strap; 4. Knee joint assembly; 5. Lower support; 6. L-shaped connecting plate; 7. Lower leg buckle; 8. Lower leg strap; 9. Elastic drawstring; 10. Foot assembly; 2.1 Second hook; 2.2 Screw hole; 2.3 Second buckle base; 3.1 Thigh strap slot; 4.1 Baffle; 4.2 Spring guide assembly; 4.3 First pin; 4.4 Rotating plate; 4.5 Limiting sleeve; 4.2.1 Spring... 4.2.2 Spring guide rod base; 4.2.3 Threaded hole; 4.2.4 First spring; 4.2.5 Spring guide rod; 7.1 First hook; 7.2 Screw hole; 7.3 First buckle base; 8.1 Lower leg strap groove; 10.1 Second spring; 10.2 Second pin; 10.3 Limit pin; 10.4 Third pin; 10.5 Fourth pin; 10.6 Second connecting plate; 10.7 First connecting plate; 10.8 Slider; 10.9 Housing. Detailed Implementation

[0025] like Figure 1As shown, this embodiment of a variable stiffness exoskeleton structure includes a thigh component, a variable stiffness knee joint component 4, a lower leg component, and a foot component 10. Overall, the thigh and lower leg components primarily secure the wearer's lower limbs; the variable stiffness knee joint primarily enables joint movement during walking; and the foot component provides support and cushioning. All of the above components appear in pairs.

[0026] like Figure 1 As shown, the thigh strap 3 not only has a fixing function, but also bears a certain force. The force is mainly transmitted to the upper support 1 through the thigh buckle 2, then to the lower support 5 through the variable stiffness knee joint component 4, and finally to the foot component 10. Similarly, the calf strap 8 also plays a fixing role and bears a certain load. The force is mainly transmitted to the L-shaped connecting plate 6 through the calf buckle 7, and then to the ground through the shell (10.9) or directly to the ground (the bottom of the L-shaped connecting plate 6 is in direct contact with the ground and is also connected to the shell (10.9)).

[0027] In terms of specific structure, such as Figure 2 , 3 As shown, the upper support 1 and the thigh strap 3 are connected together by the thigh buckle 2, which is connected to the upper support 1 by screws. The thigh buckle 2 includes a second hook 2.1 and a second buckle base 2.3. The second hook 2.1 is engaged with the thigh strap groove 3.1. The second buckle base 2.3 is connected to the upper support 1 by screws through screw holes, which helps to achieve good fixation between the wearer's thigh and the thigh component, ensuring that it will not fall off during walking. The thigh strap 3 can be modified according to the thigh size of different operators.

[0028] like Figure 4 As shown, the variable stiffness knee joint assembly 4 includes a baffle 4.1, a spring guide assembly 4.2, a first pin 4.3, a rotating plate 4.4, and a limiting sleeve 4.5. The baffle 4.1 is inverted L-shaped and includes a fixedly connected support part and a limiting part. The support part at the top of the baffle 4.1 has a threaded hole for direct connection to the upper bracket, and a through hole at the right end. The rotating plate 4.4 also has a through hole on its right side and is connected to the support part of the baffle 4.1 by the first pin 4.3, allowing the rotating plate 4.4 to rotate around the first pin 4.3. The limiting part is used to limit the rotation limit of the rotating plate 4.4 and supports the rotating plate when it reaches the rotation limit. The limiting sleeve 4.5 is fixed to the end of the spring guide assembly 4.2 and can limit the maximum rotation angle of the rotating plate 4.4.

[0029] An abutment step is provided between the support part and the limiting part of the baffle. The rotating plate 4.4 is provided with an abutment plate. When the extension directions of the thigh assembly and the lower leg assembly are parallel, the abutment plate of the rotating plate 4.4 abuts against the abutment step of the baffle. The abutment plate gives the abutment step a force parallel to the extension directions of the thigh assembly and the lower leg assembly. The lower leg assembly supports the thigh assembly.

[0030] like Figure 5 As shown, the spring guide assembly 4.2 includes a spring guide rod base 4.2.1, a threaded hole 4.2.2, a first spring 4.2.3, and a spring guide rod 4.2.4. The spring guide rod base 4.2.1 is directly connected to the support part of the baffle 4.1; one end of the spring guide rod 4.2.4 is fixedly connected to the support part of the baffle 4.1, and the other end passes through the first spring 4.2.3 and then through the through hole of the rotating plate 4.4. The spring guide rod 4.2.4 can restrict the movement trajectory of the first spring 4.2.3 to ensure that its movement trajectory matches the rotation trajectory of the rotating plate 4.4.

[0031] The calf assembly includes a lower support 5, a connecting plate 6, a calf buckle 7, and a calf strap 8, such as Figure 6 , 7 As shown, the lower support 5 and the calf strap 8 are connected together by a calf buckle 7, which is connected to the lower support 5 by screws. The calf buckle 7 includes a first hook 7.1 and a first buckle base 7.3; the first hook 7.1 engages with the calf strap groove 8.1; the first buckle base 7.3 is connected to the connecting plate 6 by screws through screw holes. The calf buckle 7 helps to secure the wearer's calf to the calf assembly, ensuring that it will not fall off during walking. The calf strap 8 can be modified according to the calf size of different operators.

[0032] like Figure 8 As shown, the foot assembly 10 includes a second spring 10.1, a second pin 10.2, a limiting pin 10.3, a third pin 10.4, a fourth pin 10.5, a second connecting plate 10.6, a first connecting plate 10.7, a slider 10.8, and a housing 10.9. The second spring 10.1 is installed on the left side inside the housing 10.9 and is fixedly connected to the slider 10.8. The slider 10.8 reciprocates linearly within the housing 10.9 via the second spring 10.1. A limiting baffle is provided inside the housing 10.9 to restrict the movement distance of the slider 10.8. The second spring 10.1 can collect energy through the compression of the slider 10.8. The left side of the first connecting plate 10.7 is connected to the slider 10.8 via the second pin 10.2, and the right side is connected to the lower end of the lower bracket 5 and the left end of the second connecting plate 10.6. The right side of the second connecting plate 10.6 is connected to the housing 10.9, as detailed below. Figure 9 As shown, this design can achieve the up-and-down reciprocating motion of the lower bracket 5 through the movement of the slider, the limiting pin 10.3, and the baffle 4.1.

[0033] When a person is standing, the structure is as follows: Figure 1 As shown, in the engaged state, the first connecting plate 10.7 and the second connecting plate 10.6 are aligned in a straight line. Since the upper end of the housing 10.9 is provided with a baffle 4.1, the first connecting plate 10.6 and the second connecting plate 10.6 will not experience any movement uncertainty. The first connecting plate 10.7 pushes the slider 10.8 to slide to the left, and the slider 10.8 compresses the second spring 10.1 to store energy. The first connecting plate 10.7 and the second connecting plate 10.6 lift the lower support 5 upward. The bottom surface of the lower support 5 is a plane, which can keep it perpendicular to the ground. The elastic rope 9 pulls the lower support 5 to generate a counterclockwise rotation force, which, together with the limiting device, further ensures the verticality of the lower support 5. The lifting of the lower support 5 causes the rotating plate 4.4 to be pressed clockwise, and finally limited by the baffle 4.1. The abutment plate abuts against the abutment step of the baffle, so that its lower surface presses against the top of the lower support 5. The rotation of the rotating plate 4.4 also causes the first spring 4.2.3 to be pressed down, so that it completes the energy storage.

[0034] When the wearer first starts walking, the impact force is generated when the heel contacts the ground. At this time, one side of the V-shaped pressing device composed of the first connecting plate 10.7 and the second connecting plate 10.6 contacts the ground, and the second spring 10.1 built into its shell will absorb part of the buffer force. At the same time, the elastic pull rope 9 pulls the lower bracket 5 to continuously adhere to the inner side of the baffle 4.1, and the resulting friction further offsets the impact force.

[0035] When the wearer is walking, the V-shaped pressing device composed of the first connecting plate 10.7 and the second connecting plate 10.6 is in contact with the ground and is flattened. The lower support 5 is lifted up, and the top of the lower support 5 presses the rotating plate 4.4. The rotating plate 4.4 presses the first spring 4.2.3, which plays a certain role in cushioning.

[0036] During the later stages of the wearer's walking, the V-shaped pressing device composed of the flattened first connecting plate 10.7 and the second connecting plate 10.6 returns to its flattened state, driving the slider 10.8 to move. The force stored in the second spring 10.1 is released, causing a portion of the thrust at the bottom of the lower support 5, which can effectively provide pushing assistance. At this time, the rotating plate 4.4 will be rotated counterclockwise by the force stored in the first spring 4.2.3, which is transmitted to the top of the lower support 5 through the bottom surface of the rotating plate 4.4. At the same time, the lower support 5 will also generate a portion of the thrust, which can also effectively provide pushing assistance.

Claims

1. A variable stiffness knee exoskeleton structure, characterized in that, The device includes a thigh assembly, a variable stiffness knee joint assembly (4), and a lower leg assembly connected from top to bottom. The variable stiffness knee joint assembly (4) includes a baffle (4.1), a spring guide assembly (4.2), a rotating plate (4.4), and a limiting sleeve (4.5). The baffle (4.1) is inverted L-shaped and includes a fixedly connected support part and a limiting part. The thigh assembly is fixedly connected to the upper surface of the support part of the baffle (4.1), and the lower leg assembly is fixedly connected to the rotating plate (4.4). The rotating plate (4.4) is hinged to one end of the support part, and a spring guide assembly (4.2) is provided between the rotating plate (4.4) and the support part. The limiting part is used to limit the rotation limit of the rotating plate (4.4) and support the rotating plate when the rotating plate reaches the rotation limit.

2. The variable stiffness knee exoskeleton structure according to claim 1, characterized in that, An abutting step is provided between the supporting part and the limiting part of the baffle, and an abutting plate is provided on the rotating plate (4.4). When the extension directions of the thigh assembly and the calf assembly are parallel, the abutting plate of the rotating plate (4.4) abuts against the abutting step of the baffle. The abutting plate gives the abutting step a force parallel to the extension directions of the thigh assembly and the calf assembly, and the calf assembly supports the thigh assembly.

3. The variable stiffness knee exoskeleton structure according to claim 1, characterized in that, The spring guide assembly (4.2) includes a spring guide rod base (4.2.1), a first spring (4.2.3), a spring guide rod (4.2.4), and a limiting sleeve (4.5). The spring guide rod base (4.2.1) is fixedly connected to the lower surface of the support portion of the baffle (4.1). The rotating plate (4.4) is provided with a through hole. One end of the spring guide rod (4.2.4) is fixedly connected to the support portion of the baffle (4.1), and the other end passes through the first spring (4.2.3) and then through the through hole of the rotating plate (4.4). The limiting sleeve (4.5) is fixed to the end of the spring guide rod (4.2.4) to limit the rotation angle of the rotating plate (4.4).

4. The variable stiffness knee exoskeleton structure according to claim 1, characterized in that, The lower leg assembly is connected to the foot assembly at the bottom. The lower leg assembly includes a lower support (5) and a connecting plate (6). One end of the lower support (5) is fixedly connected to the rotating plate (4.4), and the other end is connected to the foot assembly. One end of the connecting plate (6) is connected to the foot assembly to fix the user's lower leg.

5. The variable stiffness knee exoskeleton structure according to claim 4, characterized in that, The foot assembly includes a housing (10.9) externally hinged to the lower leg assembly, and a second spring disposed within the housing. 10.1) and slider (10.8), one end of the second spring (10.1) is fixedly connected to the inside of the housing (10.9), and the other end is fixedly connected to the slider (10.8). A first connecting plate (10.7) is hinged on the slider (10.8). One end of the first connecting plate (10.7), the lower end of the lower bracket (5) and one end of the second connecting plate (10.6) are hinged to each other. The other end of the second connecting plate (10.6) is hinged to the housing (10.9). One end of the connecting plate (6) is fixedly connected to the housing (10.9). The slider (10.8) moves in the housing along the direction of extension of the vertical connecting plate (6) to realize the movement of the lower end of the lower bracket (5).

6. The variable stiffness knee exoskeleton structure according to claim 5, characterized in that, The housing (10.9) is provided with a limiting hole, and a limiting pin (10.3) is provided in the limiting hole. The limiting pin is used to limit the rotation of the lower bracket (5).

7. The variable stiffness knee exoskeleton structure according to claim 5, characterized in that, The foot assembly also includes an elastic pull cord (9), one end of which is fixedly connected to the slider and the other end is fixedly connected to the middle of the lower bracket (5).

8. The variable stiffness knee exoskeleton structure according to claim 5, characterized in that, A limiting baffle is provided inside the housing (10.9) to limit the movement distance of the slider (10.8).

9. The variable stiffness knee exoskeleton structure according to claim 4, characterized in that, The calf assembly also includes a calf buckle (7) and a calf strap (8). The calf buckle (7) fixes the calf strap (8) to the connecting plate (6). The calf strap (8) is worn on the user's calf. The calf buckle (7) includes a first hook (7.1) and a first buckle base (7.3). The first hook (7.1) engages with the calf strap slot (8.1). The first buckle base (7.3) is connected to the connecting plate (6) by screws through screw holes.

10. The variable stiffness knee exoskeleton structure according to claim 1, characterized in that, The thigh assembly includes an upper bracket (1), a thigh buckle (2), and a thigh strap (3). The bottom end of the upper bracket (1) is fixedly connected to the upper surface of the support part of the baffle (4.1). The thigh buckle (2) fixes the thigh strap (3) to the upper bracket (1). The thigh strap (3) is used to be worn on the user's thigh. The thigh buckle (2) includes a second hook (2.1) and a second buckle base (2.3). The second hook (2.1) is engaged with the thigh strap groove (3.1). The second buckle base (2.3) is connected to the upper bracket (1) by a screw through a screw hole.

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