CN216781815U

CN216781815U - Passive touchdown knee joint exoskeleton robot

Info

Publication number: CN216781815U
Application number: CN202123245665.3U
Authority: CN
Inventors: 陈晓; 马建峰; 孙得成; 王刚; 王惜亮
Original assignee: Beijing University of Technology; Institute of Quartermaster Engineering Technology Institute of Systems Engineering Academy of Military Sciences
Current assignee: Beijing University of Technology; Institute of Quartermaster Engineering Technology Institute of Systems Engineering Academy of Military Sciences
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2022-06-21
Anticipated expiration: 2031-12-22

Abstract

The utility model relates to a passive touchdown knee joint exoskeleton robot, which comprises the following components: a thigh mechanism comprising a thigh bar; the knee joint energy storage mechanism comprises a knee joint component, an elastic rod and a foot component, wherein the upper end of the elastic rod is connected with the knee joint component, the lower end of the elastic rod is connected with the foot component, the knee joint component is connected with the lower end of the thigh rod, and the knee joint energy storage mechanism is used for storing and releasing gravitational potential energy of a human body in the walking process; the shank mechanism comprises a shank rod, and the upper end and the lower end of the shank rod are respectively connected with the knee joint component and the foot component. The device has the advantages of simple structure, light weight, convenient wearing, stability, reliability, reasonable working principle and obvious assistance.

Description

Passive touchdown knee joint exoskeleton robot

Technical Field

The utility model relates to a passive touchdown knee joint exoskeleton robot, in particular to a passive touchdown knee joint exoskeleton robot based on elastic rod energy storage, and belongs to the technical field of passive lower limb exoskeleton.

Background

The basic difference between human and animals is that people are good at making and using tools, the exoskeleton is one of the tools for expanding human body functions and carrying capacity, and compared with vehicles such as automobiles, high-speed rails and bicycles, the exoskeleton has the advantages that the exoskeleton can flexibly follow the limb movement of the human body and can provide assistance for the human body under various working conditions including forests, lawns, sand beaches, roads and the like.

The current development bottleneck of the power exoskeleton is not in a core algorithm, but in a power module with a small degree of relation with the exoskeleton design, because the current density of batteries is not enough to meet the long-time operation requirement of the exoskeleton robot under outdoor conditions, the passive exoskeleton discards the problem and attempts to finish the exercise assistance to the limbs of the human body by more reasonably distributing the energy of the human body. Most passive exoskeletons now perform functions that are more biased toward assisting in sharing the load carried by the body, and are somewhat more powerful when assisted, while passive exoskeletons offer the additional advantage of being lightweight and flexible relative to powered exoskeletons, however, some passive mechanisms are not much more effective in this regard.

Disclosure of Invention

The utility model provides a passive touchdown knee joint exoskeleton robot, which is simple in structure, light in size, convenient to wear, stable and reliable, reasonable in working principle and obvious in assistance.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a passive touchdown knee joint exoskeleton robot comprises the following components:

a thigh mechanism comprising a thigh bar;

the knee joint energy storage mechanism comprises a knee joint component, an elastic rod and a foot component, wherein the upper end of the elastic rod is connected with the knee joint component, the lower end of the elastic rod is connected with the foot component, the knee joint component is connected with the lower end of the thigh rod, and the knee joint energy storage mechanism is used for storing and releasing gravitational potential energy of a human body in a walking process;

and the lower leg mechanism comprises a lower leg rod, and the upper end and the lower end of the lower leg rod are respectively connected with the knee joint component and the foot component.

Preferably, the knee joint component comprises an outer end cover of the knee joint and an inner end cover of the knee joint connected with the outer end cover of the knee joint, a cavity is formed between the outer end cover of the knee joint and the inner end cover of the knee joint, a deep groove ball bearing, a cam and a cam rod of the knee joint are assembled in the cavity, the deep groove ball bearing and the cam jointly form a rotating pair, the cam is connected with the lower end of the thigh rod, and the cam rod of the knee joint jointly form a cam pair.

Preferably, the foot component comprises a linear bearing wrapping part, a sole push rod and a linear bearing, the upper end of the sole push rod is connected with the lower end of the elastic rod through an ankle joint interface, the lower end of the sole push rod is sleeved with the linear bearing ring to form a cylindrical pair, the lower end of the sole push rod is connected with the linear bearing wrapping part, and the lower end of the shank rod is connected with the linear bearing wrapping part.

The passive touchdown knee joint exoskeleton robot preferably further comprises a shoe cover, the shoe cover is connected with the shank rod through a joint bearing, the upper end of the shank rod is connected with the lower end of the outer end cover of the knee joint, and the lower end of the shank rod is connected with the shoe cover.

Preferably, the upper end of the elastic rod is connected with the knee joint cam rod through a knee joint interface, and the knee joint interface is hinged to the lower end of the knee joint cam rod through a cylindrical pin.

The passive touchdown knee joint exoskeleton robot is characterized in that a roller bearing is preferably arranged between the cam and the knee joint cam rod and used for preventing the knee joint cam rod from moving downwards due to gravity in a swinging period to cause an overlarge gap between the cam pairs.

The passive touchdown knee joint exoskeleton robot preferably comprises a knee joint cam rod, a knee joint outer end cover and a knee joint cam rod, wherein the knee joint cam rod is in contact with the knee joint outer end cover through two groups of roller bearings, and each group comprises at least two roller bearings.

The passive touchdown knee joint exoskeleton robot preferably further comprises a ground contact disc, wherein the ground contact disc is assembled at the lower end of the linear bearing wrapping piece.

The passive touchdown knee joint exoskeleton robot further comprises a thigh fixing part, wherein the thigh fixing part is provided with a bandage hole for accommodating a bandage to pass through so as to bind the thigh rod with the thigh of the human body;

the shank mechanism further comprises a shank fixing piece, wherein the shank fixing piece is also provided with a strap hole for accommodating a strap to pass through so as to bind the shank rod and the shank of the human body together.

Based on the passive touchdown knee joint exoskeleton robot, the utility model also provides a power assisting method of the robot, which comprises the following steps:

when a patient wearing the passive touchdown knee joint exoskeleton robot walks, in the process that the heel of a human body supporting leg gradually contacts the ground completely, the ground contact disc and the sole push rod move upwards relative to the human body to press the elastic rod to deform, the bending degree of the elastic rod is increased, the knee joint interface rotates anticlockwise relative to the knee joint cam rod due to the bending of the elastic rod, and the ankle joint interface rotates clockwise relative to the upper end of the sole push rod;

when the knee joint of the human body supporting leg is further bent backwards, the knee joint cam rod rolls clockwise around the cam under the action of the lower leg mechanism through the roller bearing, in the process, as the curvature radius of the contact part of the knee joint cam rod and the cam is continuously increased, the lower end of the knee joint cam rod moves downwards relative to the lower leg mechanism, and meanwhile, as the ground contact round cake is contacted with the ground, the spatial position of the sole push rod is fixed, the bending deformation of the elastic rod is further caused, so that the purpose of storing energy when the knee joint of the human body supporting leg is bent backwards by the passive touchdown knee joint exoskeleton robot is realized;

when the human body supporting legs are further converted into swing legs, in the process of leaving the ground along with feet, the pressing of the sole push rods on the elastic rods is gradually reduced, the elastic rods give assistance compensation to the human body in the ground leaving direction through the foot components, and in the process, the human body and the gravitational potential energy part reduced by the weight carried by the human body are fed back to the human body before the legs of the passive ground-contacting knee joint exoskeleton robot are recovered to enter the supporting period.

Due to the adoption of the technical scheme, the utility model has the following advantages:

1. the knee joint energy storage mechanism has a clutch function and an energy storage function, the knee joint energy storage mechanism utilizes a heel-to-ground phenomenon as a clutch control signal, energy storage is realized by utilizing a mode that the displacement of a knee joint cam rod in an inverted cam pair and the compression amount of an elastic rod are mutually converted in a supporting period, and the exoskeleton is ensured not to generate obvious interference on the knee joint of a human body when the knee joint is separated in a swinging period.

2. The knee joint cam rod in the knee joint component is in contact with the outer end cover of the knee joint through two groups of four roller bearings, and the structural design aims to convert the complex space contact force between the two roller bearings into two component forces respectively on the sagittal plane and the coronal plane and respectively borne by the two groups of bearings so as to prevent the two components from being blocked due to the complex contact force.

3. The compression amount of the elastic rod is adjustable, the power assisting effect of the knee joint is adjusted according to different people, and the knee joint energy storage mechanism can recover gravitational potential energy falling when the supporting leg falls to the ground and assist the power when the supporting leg falls to the ground.

4. The device has the advantages of simple structure, light and handy body type, convenience in wearing, stability, reliability, reasonable working principle and obvious assistance.

Drawings

Fig. 1 is a schematic overall structure diagram of a passive touchdown knee exoskeleton robot according to an embodiment of the present invention;

fig. 2 is an exploded view of the components of the passive touchdown knee exoskeleton surrounding a knee joint convergence zone (knee joint assembly) according to this embodiment of the present invention;

FIG. 3 is an exploded view of the components of the passive touchdown knee exoskeleton surrounding the foot gathering area (foot assembly) according to this embodiment of the present invention;

FIG. 4 is an exploded view of the passive touchdown knee exoskeleton according to this embodiment of the present invention;

the respective symbols in the figure are as follows:

1-thigh mechanism, 101-thigh rod, 102-thigh fixing piece; 2-a knee joint component; 3-an elastic rod; 4-shank mechanism, 401-shank rod, 402-shank part fixing piece; 5-a foot component; 6-shoe cover; 7-knee joint interface; 8-roller bearings; 9-knee joint outer end cover; 10-Saida screws; 11-knee cam lever; 12-a cam; 13-deep groove ball bearing; 14-knee joint inner end cap; 15-hexagon socket head flat round head screw; 16-linear bearing wrap; 17-sole push rod; 18-linear bearings; 19-ankle joint interface; 20-knuckle bearing; 21-a screw; 22-slotted pan head self-tapping screw; 23-ground contact patty.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention are described clearly and completely below, and it is obvious that the described embodiments are some, not all embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without making any creative efforts shall fall within the protection scope of the present invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. As used herein, the terms "first," "second," "third," "fourth," and the like do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

As shown in fig. 1, the passive touchdown knee joint exoskeleton robot provided by the utility model comprises the following components:

a thigh mechanism 1 including a thigh lever 101; the knee joint energy storage mechanism comprises a knee joint component 2, an elastic rod 3 and a foot component 5, wherein the upper end of the elastic rod 3 is connected with the knee joint component 2, the lower end of the elastic rod 3 is connected with the foot component 5, the knee joint component 2 is connected with the lower end of a thigh rod 101, and the knee joint energy storage mechanism is used for storing and releasing gravitational potential energy of a human body in a walking process; the lower leg mechanism 4 comprises a lower leg rod 401, and the upper end and the lower end of the lower leg rod 401 are respectively connected with the knee joint component 2 and the foot component 5. The elastic rod 3 in the utility model is all elastic elements with bending elastic energy storage, such as a spring rigid rod, a carbon fiber rod, a high-elasticity composite material and the like.

As shown in fig. 1, the lower leg mechanism 4 is composed of a lower leg rod 401 fixed to each other by screws and two lower leg fixing pieces 402, and the lower leg mechanism 4 is bound to the outer side of the lower leg of the human body in parallel by a binding band passing through elongated strap holes of the two lower leg fixing pieces 402. Elastic rod 3 can give cam 12 a vertical ascending external force at crooked in-process, this external force transmits the solid disjunctor of inner end cover 14 and the outer end cover 9 of knee joint to knee joint through deep groove ball bearing 13, because outer end cover 9 of knee joint and shoe cover 6 are connected at shank mechanism 4 both ends, this external force will finally transmit to the sole from the outer end cover 9 of knee joint through shank pole 401, overcome the deformation counter-force of elastic rod 3 through the mode that the human body stepped on downwards, in order to overcome the bandage and tie up the shortcoming that does not lean on.

As shown in fig. 1, the thigh mechanism 1 is composed of a thigh rod 101 and two thigh fixing pieces 102, which are fixed to each other by screws, and a binding band is passed through elongated strap holes of the two thigh fixing pieces 102 to bind the thigh mechanism to the outer side of the thigh of the human body in parallel, and the lower end of the thigh rod 101 is connected to the cam 12 in the knee joint assembly 2 by screws in order to keep the cam 12, the thigh mechanism 1, and the thigh of the human body fixed to each other.

As shown in fig. 2, the knee joint component in the knee joint energy storage mechanism includes: the knee joint interface 7, the roller bearing 8, the outer end cover 9 of the knee joint, the Saida screw 10, the cam lever 11 of the knee joint, the cam 12, the deep groove ball bearing 13, the inner end cover 14 of the knee joint and the hexagon socket head flat round head screw 15. The cam 12 is connected to the thigh mechanism 1 by means of a hexagon socket head flat head screw 15. The knee joint outer end cover 9 and the knee joint inner end cover 14 are connected and fixed through inner hexagonal flat round head screws 15, a deep groove ball bearing 13 and a cam 12 jointly form a rotating pair, a knee joint interface 7 is hinged to the lower end of a knee joint cam rod 11 and connected with the upper end of an elastic rod 3 through threads, and a roller bearing 8 is fixed on the right side plane of the cam 12 through the inner hexagonal flat round head screws 15 so as to prevent the knee joint cam rod 11 from moving downwards due to the action of gravity in the swinging period to cause overlarge gap between the cam pairs (the knee joint cam rod 11 and the cam 12). The inner diameter of the deep groove ball bearing 13 is in interference fit with a left side cylinder of the cam 12, four inner hexagonal flat round head screws 15 screwed out of the left side cylinder of the cam 12 from inside to outside are extruded together to ensure tight fit between components, the outer diameter of the deep groove ball bearing 13 is in clearance fit with an inner end cover 14 of the knee joint and is extruded together through four inner hexagonal flat round head screws 15 screwed into the inner end cover 14 of the knee joint from outside to inside to ensure tight fit between the components, and the purpose of contacting the knee joint cam rod 11 with the outer end cover 9 of the knee joint through four roller bearings 8 in total in two groups is to change complex space contact forces between the two space contact forces into two component forces in a sagittal plane and a coronal plane respectively and to prevent the two components from being blocked due to complex contact forces respectively borne by the two groups of bearings.

As shown in fig. 3, the foot assembly in the knee energy storage mechanism comprises: linear bearing wrap 16, foot pushrod 17, linear bearing 18, ankle joint interface 19, and ground contact puck 23. The ankle joint interface 19 is hinged to the upper end of the sole push rod 17 and is connected with the lower end of the elastic rod 3 through threads, the linear bearing wrapping piece 16 is fixed in the shank 401 through four inner hexagonal flat round head screws 15 and is fixed with the linear bearing 18 through four front and rear slotted pan head self-tapping screws 22, the linear bearing 18 and the sole push rod 17 form a cylindrical pair, and the ground contact round cake 23 is connected with the sole push rod 17 through the inner hexagonal flat round head screws 15; the cover 6 is attached 401 to the inside of the calf by means of a knuckle bearing 20 and three hexagonal socket head screws 15.

As shown in fig. 3, the shoe cover 6 is connected to the shank 401 through the joint bearing 20, and is bound to the foot of the human body by a binding band, specifically: slender strap holes are dug in the left front structural beam, the right front structural beam, the left front quarter protruding round cake-shaped structure and the back part, and lightening holes are dug in other positions.

As shown in fig. 3, a roller bearing 8 is fixed on the right plane of the cam 12 through a hexagon socket head flat round head screw 15, so that the knee joint cam rod 11 is hindered by the roller bearing 8 during the swing period, which ensures that the gap between the cam pairs (the knee joint cam rod 11 and the cam 12) is not too large, and when the further extension of the human knee joint is finished, the lower limb exoskeleton starts to operate along with the human body in the next dynamic period.

As shown in fig. 4, the energy storage principle of the knee joint energy storage mechanism is to realize energy storage by converting the stroke of the knee joint cam rod 11 in the inverted cam pair (the knee joint cam rod 11 and the cam 12) and the vertical compression amount of the elastic rod 3 into each other. The cam 12 is connected to the thigh rod 101 through a bolt, the cam has a certain inclined plane inclination angle in an initial working state, inner and outer end covers of a knee joint are relatively fixed after being connected through the bolt, a rotary pair is formed by the cam 12 and the deep groove ball bearing 13 together, a knee joint interface 7 is hinged to the lower end of the knee joint cam rod 11 through a cylindrical pin and is connected with the upper end of the elastic rod 3 through a thread, an ankle joint interface 19 is hinged to the upper end of the sole push rod 17 through a bolt, the ankle joint interface is connected with the lower end of the elastic rod 3 through a thread, a linear bearing wrapping piece 16 is fixed to the shank rod 401 through a screw, a cylindrical pair is further formed by the linear bearing 18 and the sole push rod 17, and a ground contact round cake 23 is connected to the sole push rod 17 through a countersunk bolt.

In addition, the knee joint energy storage mechanism recovers the gravitational potential energy part of the human body and the human body carrying heavy objects and the like before entering the supporting period, and provides assistance compensation for the lift-off direction of the human body through the foot components 5 and the elastic rods 3 when the feet lift off the ground later. Specifically, as the thigh mechanism 1 and the shank mechanism 4 are respectively bound on the thigh and the shank of the human body through the binding band, the rotation angle of the outer end cover 9 of the knee joint and the inner end cover 14 of the knee joint and the cam 12 together will be determined by the knee joint of the human body, in the process that the heel of the supporting leg gradually contacts the ground completely, the ground contact round cake 23 and the sole push rod 17 move up relatively to the human body to press the elastic rod 3 to deform, at the moment, the bending degree of the elastic rod 3 is increased, the knee joint interface 7 rotates counterclockwise relative to the knee joint cam rod 11 due to the bending of the elastic rod 3 and the ankle joint interface 19 rotates clockwise relative to the upper end of the sole push rod 17, the process not only realizes the pre-deformation of the elastic rod 3, but also can recover the human body and the parts which carry heavy objects and the like and reduce gravitational potential energy.

As shown in figure 4, when the knee joint of the supporting leg is further bent backwards, the knee joint cam rod 11 can roll clockwise around the inclined plane of the cam 12 under the action of the lower leg mechanism 4 through the roller bearing 8 and the Sadada screw 10, in the process, the curvature radius of the contact part of the knee joint cam rod 11 and the cam 12 is continuously increased, the lower end of the knee joint cam rod 11 can move downwards relative to the lower leg mechanism 4, and meanwhile, the space position of the sole push rod 17 is fixed due to the fact that the ground contacts with the round cake 23, and the elastic rod 3 can be further bent and deformed, so that the purpose that the knee joint energy storage mechanism stores energy when the knee joint of the human supporting leg is bent backwards is achieved. When the knee joint of the subsequent human body supporting leg extends forwards, the curvature radius of the contact part of the knee joint cam rod 11 and the cam 12 is continuously reduced, the knee joint cam rod 11 gradually reduces the compression on the elastic rod 3, the elastic rod 3 gradually recovers to the initial deformation state, the potential energy stored when the knee joint is bent backwards is fed back to the human body in the process, and the purpose that the knee joint energy storage mechanism releases energy when the knee joint of the human body supporting leg extends forwards is achieved.

As shown in figure 4, when the human body supporting leg is further converted into a swing leg, in the process of heel off the ground, the compression of the elastic rod 3 by the foot push rod 17 is gradually reduced, the elastic rod 3 gives the human body assistance compensation in the off-ground direction through the foot component 5, and the process feeds back the reduced gravitational potential energy parts of the human body and the heavy object carried by the human body to the human body before the leg is recovered by the knee joint energy storage mechanism to the supporting period.

As shown in fig. 4, when the human knee joint is bent backwards in the swing period, the ground contact disc 23 is separated from the ground contact, so that the sole push rod 17 can slide up and down along the linear bearing 18 and the linear bearing wrapping piece 16, due to the gravity and the factors such as the increasing of the curvature radius of the contact part of the knee joint cam rod 11 and the cam 12, the lower end of the knee joint cam rod 11 moves down relative to the shank mechanism 4 and does not press the elastic rod 3, and the downward movement of the lower end of the knee joint cam rod 11 is finally transmitted to the sole push rod 17 through the elastic rod 3 to slide up and down along the linear bearing 18 and the linear bearing wrapping piece 16.

The knee joint energy storage mechanism has a clutch function and an energy storage function. The knee joint energy storage mechanism utilizes the heel touchdown phenomenon as a clutch control signal, realizes energy storage by utilizing a mode that the displacement of a knee joint cam rod 11 in the inverted cam pair and the compression amount of the elastic rod 3 are mutually converted in a supporting period, and ensures that the exoskeleton does not generate obvious interference on the knee joint of a human body when the exoskeleton is separated in a swinging period. Specifically, the method comprises the following steps: the knee joint energy storage mechanism recovers the negative joint work when the knee joint is flexed in the knee joint support period and transfers or compensates the positive joint work when the knee joint is stretched. In addition, the knee joint energy storage mechanism recovers the part of the human body and the gravitational potential energy reduced by the human body carrying heavy objects and the like before entering the supporting period, and provides assistance compensation for the lift-off direction of the human body when the feet lift off the ground later.

The clutch effect of the knee joint energy storage mechanism is not influenced by the motion rule error between human bodies. The knee joint energy storage mechanism has unique freedom degree, which means that the knee joint cam pairs have unique matching state under the condition of determining the human knee joint motion input (although the cam pairs are separated in the normal direction at the end of the swing period, the overall pose direction is always determined), thus, for a given wearer, the knee joint in the case of a certain dorsiflexion angle during the support phase means that the final contact state of the knee joint cam pair is the same, further determining that the amount of compression of the resilient lever 3 is constant, therefore, the final power assisting effect of the knee joint energy storage mechanism can be ensured to be constant, when the knee joint energy storage mechanism faces different motion laws of a human body, the clutch effect between the support period and the swing period can be ensured, and the backward bending error of the knee joint in the support period only determines the pose state of the cam pair in the support period.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A passive touchdown knee joint exoskeleton robot is characterized by comprising the following components:

a thigh mechanism (1) comprising a thigh bar (101);

the knee joint energy storage mechanism comprises a knee joint component (2), an elastic rod (3) and a foot component (5), the upper end of the elastic rod (3) is connected with the knee joint component (2), the lower end of the elastic rod (3) is connected with the foot component (5), the knee joint component (2) is connected with the lower end of the thigh rod (101), and the knee joint energy storage mechanism is used for storing and releasing gravitational potential energy of a human body in a walking process;

the shank mechanism (4) comprises a shank rod (401), and the upper end and the lower end of the shank rod (401) are respectively connected with the knee joint component (2) and the foot component (5).

2. The passive touchdown knee exoskeleton robot according to claim 1, wherein the knee joint assembly (2) comprises an outer knee joint cover (9) and an inner knee joint cover (14) connected with the outer knee joint cover, a cavity is formed between the outer knee joint cover and the inner knee joint cover, a deep groove ball bearing (13), a cam (12) and a knee joint cam rod (11) are assembled in the cavity, the deep groove ball bearing (13) and the cam (12) jointly form a revolute pair, the cam (12) is connected with the lower end of the thigh rod (101), and the cam (12) and the knee joint cam rod (11) jointly form a cam pair.

3. The passive touchdown knee exoskeleton robot according to claim 1, wherein the foot assembly (5) comprises a linear bearing wrapping piece (16), a sole push rod (17) and a linear bearing (18), the upper end of the sole push rod (17) is connected with the lower end of the elastic rod (3) through an ankle joint interface (19), the linear bearing (18) is sleeved on the lower end of the sole push rod (17) and forms a cylindrical pair, the lower end of the sole push rod (17) is connected with the linear bearing wrapping piece (16), and the lower end of the shank (401) is connected with the linear bearing wrapping piece (16).

4. The passive touchdown knee exoskeleton robot according to claim 2, wherein the foot component (5) further comprises a shoe cover (6), the shoe cover (6) is connected with the shank (401) through a joint bearing (20), the upper end of the shank (401) is connected with the lower end of the outer end cover (9) of the knee joint, and the lower end of the shank (401) is connected with the shoe cover (6).

5. The passive touchdown knee exoskeleton robot according to claim 2, wherein the upper end of the elastic rod (3) is connected with the knee cam lever (11) through a knee interface (7), and the knee interface (7) is hinged to the lower end of the knee cam lever (11) through a cylindrical pin.

6. The passive touchdown knee exoskeleton robot according to claim 2, wherein roller bearings (8) are fitted between the cams (12) and the knee cam levers (11) to prevent the knee cam levers (11) from moving down due to gravity during the swing period, resulting in excessive clearance between the cam pairs.

7. The passive touchdown knee exoskeleton robot according to claim 6, wherein the knee cam lever (11) is in contact with the knee outer end cap (9) through two sets of roller bearings (8), each set containing at least two roller bearings (8).

8. The passive touchdown knee exoskeleton robot according to claim 3, wherein the foot assembly (5) further comprises a ground contact puck (23), the ground contact puck (23) being mounted to a lower end of the linear bearing package (16).

9. The passive touchdown knee exoskeleton robot according to claim 1, wherein the thigh mechanism (1) further comprises a thigh fixing part (102), and the thigh fixing part (102) is provided with a strap hole for accommodating a strap to pass through so as to bind the thigh rod (101) and the thigh of the human body together;

the shank mechanism (4) further comprises a shank fixing piece (402), wherein the shank fixing piece (402) is also provided with a bandage hole for accommodating a bandage to pass through so as to bind the shank rod (401) and a shank of a human body together.