Passive lower limb exoskeleton power assist device and method

Abstract

The present invention relates to a power-assisting device and method for a passive lower limb exoskeleton, comprising the following components: a lumbar plate; a hip joint mechanism, comprising a hip joint cam, a hip joint end cover, a straight spring and a hip joint fixed end, wherein the hip joint cam is assembled on the upper end of the hip joint end cover, the hip joint cam contacts the lumbar plate through an end face bearing, the straight spring is rotatably connected to the lower end of the hip joint end cover, and the lower end of the straight spring is connected to the hip joint fixed end; an exoskeleton thigh, wherein the upper end of the exoskeleton thigh is connected to the hip joint end cover; a knee joint energy storage mechanism, comprising a knee joint assembly, an elastic rod and a foot assembly, wherein the upper end of the elastic rod is connected to the knee joint assembly, the lower end of the elastic rod is connected to the foot assembly, the knee joint assembly is connected to the lower end of the exoskeleton thigh, and the knee joint energy storage mechanism is used to store and release the gravitational potential energy of a human body during walking; an exoskeleton calf, wherein the upper and lower ends of the exoskeleton calf are respectively connected to the knee joint assembly and the foot assembly.

Description

Technical Field

[0001] The invention relates to a power-assisting device and method for a passive lower limb exoskeleton, belonging to the technical field of passive lower limb exoskeletons. Background Art

[0002] The essence of lower limb exoskeleton technology is a mechanical device that is worn in parallel on the outside of the human body and enhances the strength and endurance of the human body in real time during the movement of the human body. Especially since the 1990s, exoskeleton technology has developed rapidly, and many universities and research institutions at home and abroad are engaged in the research of lower limb exoskeleton technology. Considering the problem of endurance caused by the restriction of contemporary battery energy storage density of active lower limb exoskeleton, and the problem of interference with normal lower limb movement of human body due to the low precision of control technology. At present, for healthy people with autonomous action ability, passive lower limb exoskeleton is the best choice. In essence, passive exoskeleton completes the recovery of negative work of human body by utilizing the compression resistance of passive elastic elements (torsion springs, straight springs or gas springs, etc.), and completes the assistance to human body in the process of element deformation recovery and energy release. According to the law of conservation of energy, the energy of passive exoskeleton ultimately comes from human body, and its essential purpose is to achieve a more rational distribution of human energy.

[0003] At present, the main research direction of passive lower limb exoskeletons is to assist the lower limbs of the human body to share the back load. It has a certain assisting effect for people who need to bear weight, but the application population of the product is relatively targeted. For ordinary people, the situation of bearing weight in daily life is relatively rare. More exoskeletons are applied in the joint movement of the lower limbs of the human body under small loads. In essence, it requires the lower limb exoskeleton to assist the lower limb joints of the human body. Considering that the energy of the lower limb exoskeleton ultimately comes from the human body itself, it is an easy-to-implement design to recover the negative work of the joints during the movement of the lower limb joints to compensate for the positive work of the joints required for subsequent joint movement. It provides a good application basis for the lower limb joints with large movements such as the hip joint, but it is enough to provide sufficient assistance to the human body for the small movements of the knee joint during the support period. Summary of the invention

[0004] The present invention provides a passive lower limb exoskeleton power-assisting device and method. The hip joint mechanism in the device realizes the storage and transfer of energy between man and machine by means of mutual conversion between cam pair stroke and spring compression, and realizes energy interaction between man and machine by means of exoskeleton thigh rod.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A passive lower limb exoskeleton power-assisting device, comprising the following components:

[0007] Waist board;

[0008] A hip joint mechanism, comprising a hip joint cam, a hip joint end cover, a straight spring and a hip joint fixed end, wherein the hip joint cam is assembled on the upper end of the hip joint end cover, the hip joint cam contacts the waist plate through an end face bearing, the straight spring is rotatably connected to the lower end of the hip joint end cover, and the lower end of the straight spring is connected to the hip joint fixed end;

[0009] An exoskeleton thigh, the upper end of which is connected to the hip joint end cover;

[0010] A knee joint energy storage mechanism, comprising a knee joint assembly, an elastic rod and a foot assembly, wherein the upper end of the elastic rod is connected to the knee joint assembly, the lower end of the elastic rod is connected to the foot assembly, the knee joint assembly is connected to the lower end of the exoskeleton thigh, and the knee joint energy storage mechanism is used to store and release the gravitational potential energy of the human body during walking;

[0011] An exoskeleton calf, wherein the upper and lower ends of the exoskeleton calf are respectively connected to the knee joint component and the foot component.

[0012] The power-assisting device of the passive lower limb exoskeleton, preferably, the hip joint mechanism also includes a roller connecting rod, a straight spring compression member and a straight spring adjustment member, the upper end of the roller connecting rod is connected to the lower end of the hip joint end cover through a hip joint roller bearing, the lower end of the roller connecting rod is connected to the upper end of the straight spring compression member, the lower end of the straight spring compression member is connected to the upper end of the straight spring, the straight spring adjustment member is assembled between the straight spring and the fixed end of the hip joint, and the hip joint cam and the hip joint roller bearing together make a cam pair.

[0013] The power-assisting device of the passive lower limb exoskeleton, preferably, the knee joint assembly includes an outer knee joint end cover and an inner knee joint end cover connected thereto, a cavity is formed between the two, a deep groove ball bearing, a cam, a torsion spring and an outer torsion spring part are installed in the cavity, the deep groove ball bearing and the cam together form a rotating pair, and the cam is connected to the lower end of the exoskeleton thigh.

[0014] The power-assisting device of the passive lower limb exoskeleton, preferably, the foot component includes a linear bearing wrap, a foot push rod and a linear bearing, the upper end of the foot push rod is connected to the lower end of the elastic rod through an ankle joint interface, the linear bearing ring is sleeved on the lower end of the foot push rod to form a cylindrical pair, the lower end of the foot push rod is connected to the linear bearing wrap, and the lower end of the calf rod is connected to the linear bearing wrap.

[0015] The power-assisting device of the passive lower limb exoskeleton, preferably, the foot component also includes a shoe cover, the shoe cover is connected to the exoskeleton calf through a joint bearing, the upper end of the exoskeleton calf is connected to the lower end of the knee joint outer end cover, and the lower end of the exoskeleton calf is connected to the shoe cover.

[0016] In the power-assisting device of the passive lower limb exoskeleton, preferably, the upper end of the elastic rod is connected to the outer part of the torsion spring through a knee joint interface, and the knee joint interface is hinged to the lower end of the outer part of the torsion spring through a cylindrical pin.

[0017] The passive lower limb exoskeleton power assist device is preferably provided with a thigh rod wrapping piece on the knee joint end cover for connecting with the skeletal thigh.

[0018] The power-assisting device of the passive lower limb exoskeleton, preferably, the foot component also includes a ground contact disc, and the ground contact disc is assembled on the lower end of the linear bearing wrapping piece.

[0019] The passive lower limb exoskeleton power-assisting device, preferably, the exoskeleton thigh further comprises a thigh fixing piece, the thigh fixing piece is provided with a strap hole for accommodating a strap passing therethrough, so as to bind the exoskeleton thigh to the human body's thigh;

[0020] The exoskeleton calf also includes a calf fixing piece, and the calf fixing piece is also provided with a strap hole for accommodating a strap to pass through so as to bind the exoskeleton calf to the human calf.

[0021] Based on the above passive lower limb exoskeleton power-assisting device, the present invention also provides a power-assisting method of the device, comprising the following steps:

[0022] The hip joint mechanism realizes energy interaction between man and machine and recovery and conversion of joint negative work at the hip joint into joint positive work by mutual conversion of the stroke of the cam and the compression amount of the torsion spring. Specifically, when the hip joint of the supporting leg gradually rotates backward relative to the human body, the hip joint cam compresses the straight spring through the roller connecting rod and the straight spring compression member to realize recovery of joint negative work at the hip joint. When the hip joint of the supporting leg gradually rotates forward relative to the human body, the straight spring promotes the rotation of the hip joint cam through the reaction of the roller connecting rod and the straight spring compression member to realize conversion of joint positive work at the hip joint.

[0023] The knee joint energy storage mechanism uses the form of sole constraint to achieve the division of the working period, the support period and the swing period. Specifically, when the foot gradually contacts the ground during the support period, the sole push rod is affected by the ground and moves upward relative to the human calf, and the torsion spring is pre-tightened through the elastic rod and the outer part of the torsion spring, and finally one end of the torsion spring is constrained. When the human body enters the swing period, the sole push rod loses the constraint of the ground and loses the fixing effect on one end of the torsion spring.

[0024] The knee joint energy storage mechanism utilizes the repeated deformation of the torsion spring to realize the extraction and conversion of the joint negative work at the knee joint of the supporting leg into the joint positive work. Specifically, the torsion spring is fixed to the constraint end of the outer part of the torsion spring during the support period. As the flexion angle of the knee joint increases during the support period, the torsion spring is compressed under the constraint of the exoskeleton thigh to store the joint negative work of the knee joint. As the flexion angle of the knee joint decreases during the support period, the exoskeleton thigh gradually reduces the constraint on the torsion spring. In this process, the torsion spring promotes the rotation of the knee joint thigh and provides joint positive work to the knee joint.

[0025] The present invention adopts the above technical solution, which has the following advantages:

[0026] 1. The hip joint mechanism of the present invention realizes the storage and transfer of energy between man and machine by means of mutual conversion between cam stroke and spring compression, and realizes energy interaction between man and machine by means of thigh rod.

[0027] 2. The compression amount of the elastic rod in the present invention is adjustable, and the assistance effect of the knee joint can be adjusted according to different people. The knee joint energy storage mechanism can recover the gravitational potential energy that drops when the supporting leg lands and provide assistance when the supporting leg leaves the ground.

[0028] 3. The device of the present invention has a simple structure, a simple and reliable design method, a broad application base, and is universal to the general public; it innovatively integrates the advantages of a powered exoskeleton and a passive exoskeleton.

[0029] 4. The present invention realizes the recovery and release of part of the gravitational potential energy reduced when the human body enters the support period, has a significant assisting effect on the movement of the lower limbs of the human body, and has broad commercial prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a power-assisting device for a passive lower limb exoskeleton provided in one embodiment of the present invention;

[0031] Figure 2 A schematic diagram of the structure of a hip joint component provided by this embodiment of the present invention;

[0032] Figure 3 A schematic diagram of the structure of a knee joint component provided by this embodiment of the present invention;

[0033] Figure 4 A motion curve of a human hip joint and a curve diagram of changes in the corresponding joint energy consumption efficiency within a gait cycle provided by the embodiment of the present invention;

[0034] Figure 5 A schematic diagram of the energy source and conversion direction of the knee joint assist device provided by this embodiment of the present invention;

[0035] Figure 6 A motion curve of a human knee joint and a curve diagram of changes in the corresponding joint energy consumption efficiency within a gait cycle provided by this embodiment of the present invention;

[0036] The marks in the figure are as follows:

[0037] 1-lumbar plate; 2-hip joint mechanism; 3-exoskeleton thigh, 301-thigh fixing part; 4-knee joint assembly; 5-elastic rod; 6-exoskeleton calf, 601-calf fixing part; 7-foot assembly; 8-shoe cover; 9-end bearing; 10-hip joint cam; 11-gasket; 12-hip joint end cover; 13-hip joint roller bearing; 14-roller connecting rod; 15-straight spring compression member; 16-straight spring; 17-straight spring Adjustment part; 18-hip joint fixed end; 19-preload adjustment knob; 20-thigh rod wrap; 21-ankle joint interface; 22-foot push rod; 23-linear bearing wrap; 24-ground contact disc; 25-torsion spring; 26-deep groove ball bearing; 27-knee joint inner end cover; 28-torsion spring outer part; 29-knee joint outer end cover; 30-knee joint interface; 31-cam; 32-linear bearing; 33-joint bearing. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work are within the scope of protection of the present invention.

[0039] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second", "third", "fourth" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0040] like Figure 1 As shown, the passive lower limb exoskeleton power-assisting device provided by the present invention comprises the following components: a lumbar plate 1; a hip joint mechanism 2, comprising a hip joint cam 10, a hip joint end cover 12, a straight spring 16 and a hip joint fixed end 18, the hip joint cam 10 is assembled on the upper end of the hip joint end cover 12, the hip joint cam 10 is in contact with the lumbar plate 1 through an end face bearing 9, the straight spring 16 is rotatably connected to the lower end of the hip joint end cover 12, and the lower end of the straight spring 16 is connected to the hip joint fixed end 18; an exoskeleton thigh 3, an exoskeleton The upper end of the skeletal thigh 3 is connected to the hip joint end cover 12; the knee joint energy storage mechanism includes a knee joint component 4, an elastic rod 5 and a foot component 7, the upper end of the elastic rod 5 is connected to the knee joint component 4, the lower end of the elastic rod 3 is connected to the foot component 7, the knee joint component 4 is connected to the lower end of the exoskeleton thigh 3, and the knee joint energy storage mechanism is used to store and release the gravitational potential energy of the human body during walking; the exoskeleton calf 6, the upper and lower ends of the exoskeleton calf 6 are respectively connected to the knee joint component 4 and the foot component 7.

[0041] Furthermore, if Figure 2 As shown, the hip joint mechanism 2 also includes a roller connecting rod 14, a straight spring compression member 15 and a straight spring adjustment member 17. The upper end of the roller connecting rod 14 is connected to the lower end of the hip joint end cover 12 through the hip joint roller bearing 13, the lower end of the roller connecting rod 14 is connected to the upper end of the straight spring compression member 15, the lower end of the straight spring compression member 15 is connected to the upper end of the straight spring 16, the straight spring adjustment member 17 is assembled between the straight spring 16 and the hip joint fixed end 18, and the hip joint cam 10 and the hip joint roller bearing 13 together make a cam pair.

[0042] Furthermore, if Figure 3 As shown, the knee joint assembly 4 includes a knee joint outer end cover 29 and a knee joint 3 end cover 27 connected thereto, and a cavity is formed between the two. A deep groove ball bearing 26, a cam 31, a torsion spring 25 and a torsion spring outer part 28 are installed in the cavity. The deep groove ball bearing 13 and the cam 31 together form a rotating pair, and the cam 31 is connected to the lower end of the exoskeleton thigh 3.

[0043] Furthermore, if Figure 3 As shown, the foot assembly 7 includes a linear bearing wrap 23, a foot push rod 22 and a linear bearing 32. The upper end of the foot push rod 22 is connected to the lower end of the elastic rod 5 through the ankle joint interface 21. The linear bearing 32 is ring-shaped on the lower end of the foot push rod 22 to form a cylindrical pair. The lower end of the foot push rod 22 is connected to the linear bearing wrap 23, and the lower end of the calf rod 5 is connected to the linear bearing wrap 23.

[0044] Furthermore, if Figure 3 As shown, the foot assembly 7 also includes a shoe cover 8, which is connected to the exoskeleton shank 6 through a joint bearing 33, the upper end of the exoskeleton shank 6 is connected to the lower end of the knee joint outer end cover 29, and the lower end of the exoskeleton shank 6 is connected to the shoe cover 8.

[0045] Furthermore, if Figure 3 As shown, the upper end of the elastic rod 5 is connected to the outer torsion spring part 28 through the knee joint interface 30, and the knee joint interface 30 is hinged to the lower end of the outer torsion spring part 28 through a cylindrical pin.

[0046] Furthermore, if Figure 2 As shown, a thigh rod wrapping piece 20 is also provided on the knee joint end cover 12 for connecting with the skeletal thigh 3 .

[0047] Furthermore, if Figure 3 As shown, the foot assembly 5 further includes a ground contact disc 24 , which is assembled on the lower end of the linear bearing wrapper 23 .

[0048] Furthermore, if Figure 1 As shown, the exoskeleton thigh 3 also includes a thigh fixing member 301, and the thigh fixing member 301 is provided with a strap hole for accommodating a strap to pass through so as to bind the exoskeleton thigh 3 to the human body's thigh;

[0049] The exoskeleton calf 6 also includes a calf fixing member 601, and the calf fixing member 601 is also provided with a strap hole for accommodating the passing of a strap to bind the exoskeleton calf 6 to the calf of the human body.

[0050] A second aspect of the present invention also provides a power assisting method of the passive lower limb exoskeleton power assisting device, comprising the following steps:

[0051] The hip joint mechanism 2 realizes energy interaction between man and machine and recovery and conversion of joint negative work at the hip joint into joint positive work by mutual conversion of the stroke of the cam 31 and the compression amount of the torsion spring 25. Specifically, when the hip joint of the supporting leg gradually rotates backward relative to the human body, the hip joint cam 10 compresses the straight spring 16 through the roller connecting rod 14 and the straight spring compression member 15 to realize recovery of joint negative work at the hip joint. When the hip joint of the supporting leg gradually rotates forward relative to the human body, the straight spring 16 promotes the rotation of the hip joint cam 10 through the reaction of the roller connecting rod 14 and the straight spring compression member 15 to realize conversion of joint positive work at the hip joint.

[0052] The knee joint energy storage mechanism uses the form of sole constraint to achieve the division of the working period, the support period and the swing period. Specifically, when the foot gradually contacts the ground during the support period, the sole push rod 22 is affected by the ground and moves upward relative to the human calf, and the torsion spring 25 is pre-tightened through the elastic rod 5 and the torsion spring outer member 28, and finally one end of the torsion spring 25 is constrained. When the human body enters the swing period, the sole push rod 22 loses the constraint of the ground and loses the fixing effect on one end of the torsion spring 25.

[0053] The knee joint energy storage mechanism utilizes the repeated deformation of the torsion spring 25 to realize the extraction and conversion of the joint negative work at the knee joint of the supporting leg into the joint positive work. Specifically, the torsion spring 25 is fixed to the constraint end of the torsion spring outer part 28 during the support period. As the flexion angle of the knee joint increases during the support period, the torsion spring 25 is compressed under the constraint of the exoskeleton thigh to store the joint negative work of the knee joint. As the flexion angle of the knee joint decreases during the support period, the exoskeleton thigh gradually reduces the constraint on the torsion spring 25. In this process, the torsion spring 25 promotes the rotation of the knee joint thigh and provides joint positive work to the knee joint.

[0054] The power-assisting device of the passive lower limb exoskeleton of the present invention incorporates the power-assisting concept of the powered exoskeleton within the definition framework of the passive lower limb exoskeleton, that is, it seeks to introduce other energies besides the work done by the torque of the lower limb joints to achieve power-assisting for the movement of the lower limbs of the human body. The specific implementation approach is to recover the gravitational potential energy reduced in the process of the legs gradually entering the support period, and to assist the subsequent extension movement of the knee joint of the supporting leg.

[0055] Specifically, the hip joint mechanism 2 recovers the joint negative work during hip extension and transfers or compensates for the joint positive work during hip flexion. The hip joint mechanism 2 realizes the storage and transfer of energy between man and machine by converting the cam pair stroke and the compression of the spring, and realizes the energy interaction between man and machine by using the exoskeleton thigh 3. The knee joint energy storage mechanism ensures that it does not interfere with the normal movement of the human knee joint during the swing period, and assists the flexion / extension movement of the human knee joint during the support period. The specific process is to recover the aforementioned gravitational potential energy and the joint negative work of the knee joint in the flexion movement during the support period and convert or compensate for the joint positive work required in the subsequent knee joint extension movement.

[0056] The energy storage principle of the knee joint energy storage mechanism includes the recovery of the gravitational potential energy of the limb's descent, in which the specific implementation method is to convert the vertical displacement of the foot push rod 22 into the elastic deformation of the torsion spring 25, and the other part is to use the posterior flexion movement of the knee joint after entering the support period to realize the recovery of the joint negative work, so as to achieve the purpose of further energy storage. Finally, the energy is released during the entire forward extension movement during the support period to compensate for the joint positive work required by the human knee joint in this interval, in which the specific implementation method is to use the mutual conversion between the knee joint flexion angle and the elastic deformation of the torsion spring 25 to complete the storage and transfer of human-machine energy.

[0057] From the perspective of the conversion path of gravitational potential energy, the inner constraint end of the fixed torsion spring 25 and the outer constraint end of the compressed torsion spring 25 realize energy recovery, and the outer constraint end of the fixed torsion spring 25 and the gradual release of the constraint of the inner end of the torsion spring 25 complete the assistance to the human body.

[0058] The main purpose of the exoskeleton calf 6 is to complete the force transmission of the knee joint energy storage mechanism. The specific transmission process is: ground → foot push rod 22 → ankle joint interface 21 → elastic rod 5 → knee joint interface 30 → torsion spring outer part 28 → torsion spring 25 → exoskeleton thigh 3 → knee joint inner end cover 27 → knee joint outer end cover 29 → exoskeleton calf 6 → shoe cover 8 → sole of the foot.

[0059] like Figure 4As shown, there are two positive and negative conversion nodes of joint energy consumption efficiency in the whole gait cycle, wherein the first node appears at about the middle point of the hip joint backward swing process, and the second node appears when the hip joint swings backward to the extreme position. The most ideal conversion principle is to store the joint negative work between the two nodes and transfer it to the joint positive work at both ends. However, this requires a clear time grasp of the position of the first node, otherwise it will cause additional burden to the human body in part of the time before the first node. However, in fact, the time when the first node appears varies from person to person, and even for the same person, it will vary due to differences in walking speed. This is obviously an unknown factor that cannot be clearly determined. However, considering the law of conservation of energy, the energy taken from the human body must eventually be compensated to the human body. The time error grasped by the first node will not cause additional waste of human energy, but can provide more energy to the human body in the power-assisting stage. Therefore, the present invention chooses to store energy during the entire hip joint backward swing stage and feed back energy to the human body when the hip joint swings forward.

[0060] like Figure 6 As shown, the design of the knee joint of the lower limb exoskeleton is somewhat different from that of the hip joint. The main responsibility of the human knee joint during the swing period is to complete the swing of the calf to facilitate the starting action of the leg migrating to the next posture. During this process, it does not bear any other load except the small amount of torque required for the calf to complete the single swing action. In other words, the main task of the knee joint during the swing period is to complete related movements rather than bear loads. Therefore, during the swing period, the design criterion of the knee joint of the lower limb exoskeleton of the present application is to ensure that there is no interference in any form of movement of the human knee joint, including movement and external force. During the support period, the human knee joint is similar to the hip joint, and also has a positive and negative torque alternation node within the front and rear swing range. Considering the same factors, the present invention sets the positive and negative torque area around the middle of the support period as the working area of ​​the knee joint mechanism.

[0061] like Figure 3 As shown, when an ordinary person walks at a normal pace, the knee joint of the supporting leg will enter the supporting period in a bent state. When the sole of the supporting leg gradually touches the bottom, the elastic rod 5 will give the torsion spring 25 a clockwise rotation deformation through the constraint end of the torsion spring outer part 28 under the upward pressure of the sole push rod 22. Its essential meaning is to create a foundation for the forward extension movement of the knee joint. In the subsequent flexion movement after the knee joint initially enters the supporting period, the knee joint energy storage mechanism uses the mutual conversion of the flexion angle of the knee joint and the deformation of the torsion spring 25 to recover the joint negative work related to the knee joint during the movement; when the knee joint is converted from the initial flexion movement to the forward extension movement during the supporting period, the above-mentioned stored joint negative work and part of the gravitational potential energy lost by the human body are compensated or converted into the joint positive work required in the forward extension process of the knee joint through the reverse conversion of the deformation of the torsion spring 25 and the flexion angle of the knee joint.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A passive lower limb exoskeleton power-assisting device, characterized in that: Includes the following components: Lumbar plate (1); A hip joint mechanism (2) comprises a hip joint cam (10), a hip joint end cover (12), a straight spring (16) and a hip joint fixed end (18), wherein the hip joint cam (10) is mounted on the upper end of the hip joint end cover (12), the hip joint cam (10) is in contact with the lumbar plate (1) via an end face bearing (9), the straight spring (16) is rotatably connected to the lower end of the hip joint end cover (12), and the lower end of the straight spring (16) is connected to the hip joint fixed end (18); An exoskeleton thigh (3), the upper end of the exoskeleton thigh (3) being connected to the hip joint end cover (12); A knee joint energy storage mechanism, comprising a knee joint component (4), an elastic rod (5) and a foot component (7), wherein the upper end of the elastic rod (5) is connected to the knee joint component (4), the lower end of the elastic rod (5) is connected to the foot component (7), and the knee joint component (4) is connected to the lower end of the exoskeleton thigh (3), and the knee joint energy storage mechanism is used to store and release gravitational potential energy of a human body during walking; An exoskeleton calf (6), wherein the upper and lower ends of the exoskeleton calf (6) are respectively connected to the knee joint component (4) and the foot component (7); The hip joint mechanism (2) further comprises a roller connecting rod (14), a straight spring compression member (15) and a straight spring adjustment member (17); the upper end of the roller connecting rod (14) is connected to the lower end of the hip joint end cover (12) via a hip joint roller bearing (13); the lower end of the roller connecting rod (14) is connected to the upper end of the straight spring compression member (15); the lower end of the straight spring compression member (15) is connected to the upper end of the straight spring (16); the straight spring adjustment member (17) is assembled between the straight spring (16) and the hip joint fixed end (18); the hip joint cam (10) and the hip joint roller bearing (13) together constitute a cam pair; The knee joint assembly (4) comprises a knee joint outer end cover (29) and a knee joint inner end cover (27) connected thereto, a cavity being formed between the two, and a deep groove ball bearing (26), a cam (31), a torsion spring (25) and a torsion spring outer member (28) being installed in the cavity, the deep groove ball bearing (26) and the cam (31) together forming a rotation pair, and the cam (31) being connected to the lower end of the exoskeleton thigh (3); The foot assembly (7) comprises a linear bearing wrapper (23), a foot push rod (22) and a linear bearing (32); the upper end of the foot push rod (22) is connected to the lower end of the elastic rod (5) via an ankle joint interface (21); the linear bearing (32) is sleeved on the lower end of the foot push rod (22) to form a cylindrical pair; the lower end of the foot push rod (22) is connected to the linear bearing wrapper (23); and the lower end of the elastic rod (5) is connected to the linear bearing wrapper (23).

2. The passive lower limb exoskeleton power assist device according to claim 1, characterized in that: The foot assembly (7) further comprises a shoe cover (8), wherein the shoe cover (8) is connected to the exoskeleton shank (6) via a joint bearing (33), the upper end of the exoskeleton shank (6) is connected to the lower end of the knee joint outer end cover (29), and the lower end of the exoskeleton shank (6) is connected to the shoe cover (8).

3. The passive lower limb exoskeleton power assist device according to claim 1, characterized in that: The upper end of the elastic rod (5) is connected to the torsion spring outer part (28) via a knee joint interface (30), and the knee joint interface (30) is hinged to the lower end of the torsion spring outer part (28) via a cylindrical pin.

4. The passive lower limb exoskeleton power assist device according to claim 1, characterized in that: The hip joint end cover (12) is also provided with a thigh rod wrapping piece (20) for connecting to the skeletal thigh (3).

5. The passive lower limb exoskeleton power assist device according to claim 1, characterized in that: The foot component (7) further comprises a ground contact disc (24), wherein the ground contact disc (24) is assembled on the lower end of the linear bearing wrapping piece (23).

6. The passive lower limb exoskeleton power assist device according to claim 1, characterized in that: The exoskeleton thigh (3) further comprises a thigh fixing piece (301), wherein the thigh fixing piece (301) is provided with a strap hole for accommodating a strap passing therethrough so as to bind the exoskeleton thigh (3) to the thigh of a human body; The exoskeleton calf (6) further comprises a calf fixing piece (601), and the calf fixing piece (601) is also provided with a strap hole for accommodating a strap passing through so as to bind the exoskeleton calf (6) to the calf of a human body.

7. A method for assisting the passive lower limb exoskeleton according to claim 3, characterized in that: The steps include: The hip joint mechanism (2) realizes energy interaction between man and machine and recovery and conversion of joint negative work at the hip joint into joint positive work by means of mutual conversion between the stroke of the cam (31) and the compression amount of the torsion spring (25). Specifically, when the hip joint of the supporting leg gradually rotates backward relative to the human body, the hip joint cam (10) compresses the straight spring (16) through the roller connecting rod (14) and the straight spring compression member (15) to realize recovery of joint negative work at the hip joint. When the hip joint of the supporting leg gradually rotates forward relative to the human body, the straight spring (16) promotes the rotation of the hip joint cam (10) through the reaction of the roller connecting rod (14) and the straight spring compression member (15) to realize conversion of joint positive work at the hip joint. The knee joint energy storage mechanism uses the form of sole constraint to achieve the division of the working period, the support period and the swing period. Specifically, when the foot gradually contacts the ground during the support period, the sole push rod (22) is affected by the ground and moves upward relative to the human body's calf, and the torsion spring (25) is pre-tightened through the elastic rod (5) and the torsion spring outer member (28), and finally one end of the torsion spring (25) is constrained. When the human body enters the swing period, the sole push rod (22) loses the constraint of the ground and loses the fixing effect on one end of the torsion spring (25); The knee joint energy storage mechanism utilizes the repeated deformation of the torsion spring (25) to extract and transform the joint negative work at the knee joint of the supporting leg into the joint positive work. Specifically, the torsion spring (25) is fixed to the constraint end of the torsion spring outer part (28) during the support period. As the flexion angle of the knee joint increases during the support period, the torsion spring (25) is compressed under the constraint of the exoskeleton thigh to store the joint negative work of the knee joint. As the flexion angle of the knee joint decreases during the support period, the exoskeleton thigh gradually reduces the constraint on the torsion spring (25). In this process, the torsion spring (25) promotes the rotation of the knee joint thigh and provides joint positive work to the knee joint.

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