CN112659109A

CN112659109A - Wearable human joint booster unit

Info

Publication number: CN112659109A
Application number: CN202110053664.4A
Authority: CN
Inventors: 唐晓强; 黎帆; 孙海宁; 侯森浩; 李东兴; 王殿君; 陈亚
Original assignee: Tsinghua University; Beijing Institute of Petrochemical Technology
Current assignee: Tsinghua University; Beijing Institute of Petrochemical Technology
Priority date: 2021-01-15
Filing date: 2021-01-15
Publication date: 2021-04-16
Anticipated expiration: 2041-01-15

Abstract

This paper discloses a wearable human joint booster unit, includes: a drive mechanism including a rotary output shaft; a cam mechanism comprising a plurality of cams, each mounted on a rotary output shaft; the flexible cable assembly comprises a plurality of flexible cables, the plurality of flexible cables correspond to a plurality of cams, and each cam is wound with one flexible cable; the flexible cable guide mechanism is used for guiding a plurality of flexible cables; and the flexible cable parallel mechanism comprises a fixed platform and a movable platform, the fixed platform is fixed on the supporting side of the human body joint, the movable platform is fixed on the force application side of the human body joint, the fixed platform is provided with flexible cable through holes, and a plurality of flexible cables penetrate through the flexible cable through holes on the fixed platform and then are connected to the movable platform. The wearable human joint power assisting device adopts an underactuated design, and the plurality of cams are driven by one rotary output shaft, so that the number of driving motors in the driving mechanism is reduced, the quality, the volume and the cost of the device are reduced, and the portability of the device is improved.

Description

Wearable human joint booster unit

Technical Field

This paper relates to but not limited to mechanical technical field, especially relates to a wearable human joint booster unit.

Background

Wearable robots, also known as exoskeletons, have been developed and used to enable a human body to perform a series of actions with the aid of a robot in a time-saving, labor-saving, safe and flexible manner, and have been used in many fields such as medical care, military, daily work, etc. The wearable robot has various mechanical structures and driving modes, and cable driving is used in the mechanical design of the exoskeleton by many researchers as a driving mode and a force transmission mode of the exoskeleton due to its characteristics.

The wearable robot with the parallel rope structure has a series of irreplaceable advantages of high human body adaptability, large moving range, light weight, convenience in applying force in multiple degrees of freedom and the like, and is an exoskeleton mechanical structure adopted by many research institutions at present. However, because the mechanical design scheme adopts a plurality of ropes, a plurality of driving motors are often needed in driving, so that the mass and the volume of the driving device are large, the portability of the robot is influenced, and the application of the robot in human body assistance is influenced. In the existing research at present, the driving part of the wearable robot with the parallel rope structure is often arranged on an experiment frame due to too large weight and volume, and is not portable.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

The embodiment of the application provides a wearable human joint booster unit, it only needs a driving motor just can drive the parallelly connected flexible cable mechanism that many flexible cables constitute, realizes multi freedom helping hand, has reduced driving motor's number, has reduced the quality, the volume and the cost of device, has improved the portability of device.

A wearable human joint assist device, comprising:

a drive mechanism including a rotary output shaft;

a cam mechanism including a plurality of cams, each of the plurality of cams being mounted on the rotary output shaft;

the flexible cable assembly comprises a plurality of flexible cables, the plurality of flexible cables correspond to the plurality of cams, and each cam is wound with one flexible cable;

a plurality of flexible cables guided by the flexible cable guide mechanism; and

the flexible cable parallel mechanism comprises a fixed platform and a movable platform, wherein the fixed platform is arranged to be fixed on the supporting side of a human joint, the movable platform is arranged to be fixed on the force application side of the human joint, the fixed platform is provided with flexible cable through holes, and the flexible cables penetrate through the flexible cable through holes on the fixed platform and are connected to the movable platform.

Among this wearable human joint booster unit, a plurality of cams among the cam mechanism all install on a rotary output shaft of actuating mechanism, and a rotary output shaft of accessible drives a plurality of cams and rotates like this, drives a plurality of cams through a driving motor and rotates promptly. Therefore, the wearable human joint power assisting device of the embodiment of the application adopts an underactuated design, one driving motor is used for controlling a plurality of flexible cables to realize power assisting of a plurality of degrees of freedom of human joints, the number of the driving motors in the driving mechanism is reduced, the quality, the size and the cost of the device are further reduced, and the portability of the device is improved.

Other features and advantages of the present application will be set forth in the description that follows.

Drawings

Fig. 1 is a schematic structural diagram of a wearable human joint power assisting device according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a wearable human joint power assisting device according to another embodiment of the present application;

fig. 3 is a schematic view of an assembly structure of a driving mechanism and a cam mechanism of the wearable human joint power assisting device according to the embodiment of the present application;

fig. 4 is a schematic structural diagram of a cam mechanism of the wearable human joint power assisting device according to the embodiment of the application;

fig. 5 is a schematic structural diagram of a fixing platform of the wearable human joint power assisting device according to the embodiment of the present application;

fig. 6 is a schematic structural view of a movable platform of the wearable human joint power assisting device according to the embodiment of the present application;

FIG. 7 is a schematic structural diagram of a guide wheel assembly of a wire guide mechanism of the wearable human joint power assist device according to the embodiment of the present application;

fig. 8 is a schematic view illustrating the length of the portion of the flexible cable between the fixed platform and the movable platform as the upper arm moves when the wearable human joint power assisting device according to the embodiment of the present application is applied to a shoulder joint;

fig. 9 is a schematic contour curve diagram of the cam mechanism of the wearable human joint power assisting device according to the embodiment of the present application;

FIG. 10 is a schematic view of a cam retraction rope of the wearable human joint power assisting device according to the embodiment of the present application;

FIG. 11 is a schematic diagram showing a comparison of the theoretical value and the actual value of the variation of the length of one wire of the wearable human joint assistance device including three inelastic wires according to the embodiment of the present application;

FIG. 12 is a schematic diagram showing a comparison of the theoretical value and the actual value of the variation of the length of another wire of the wearable human joint assistor device including three inelastic wires according to the embodiment of the present application;

FIG. 13 is a schematic diagram showing a comparison of the theoretical value and the actual value of the variation of the length of another flexible cable of the wearable body joint assistor device including three inelastic flexible cables according to the embodiment of the present application;

FIG. 14 is a simulated schematic view of the use process of the wearable human joint power assisting device applied to a shoulder joint according to the embodiment of the application;

FIG. 15 is a schematic diagram of the change in cable force during use of the wearable prosthetic joint assistor device of the present application including one inelastic cable and two elastic cables;

fig. 16 is a schematic diagram showing a comparison between a planned path and an actual path of an upper arm movement trajectory of the wearable human joint power assisting device including one inelastic flexible cable and two elastic flexible cables according to the embodiment of the present application in the use process of fig. 14;

fig. 17 is a schematic diagram illustrating a comparison between a theoretical value and an actual value of a cable force of two elastic wires in the use process of fig. 14 of the wearable human joint assist device including one inelastic wire and two elastic wires according to the embodiment of the present application;

fig. 18 is a comparison between theoretical values and actual values of the variation of the lengths of three flexible wires and an error diagram of the wearable human joint assistor device including one inelastic flexible wire and two elastic flexible wires in the use process of fig. 14 according to the embodiment of the present application.

The reference signs are:

1: a drive mechanism; 11: a drive motor; 12: a reduction gearbox; 13: a coupling; 14: an encoder; 15: rotating the output shaft;

2: a cam mechanism; 21-23: a cam; 24: a groove;

3: a flexible cable assembly; 31-33: a flexible cable; 34: a first flexible cable; 35: a second flexible cable;

4: a flexible cable guide mechanism; 41: a first flexible cable guide mechanism group; 42: a second flexible cable guide mechanism group; 43: a guide wheel assembly; 431: a supporting seat; 432: a guide wheel; 433: installing a shaft;

51: a fixed platform; 511: fixing the mounting seat; 512: a flexible cable support; 513: sheep eye nails; 514: a flexible cable through hole; 515: a screw; 516: a first flexible mat;

52: a movable platform; 521: a movable mounting base; 522: a fixing hole; 523: lightening holes; 524: a second flexible mat;

6: a human body; 61: a shoulder joint; 62: an upper arm.

Detailed Description

Embodiments of the present application will be described below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

As shown in fig. 1, the present embodiment provides a wearable human body joint power assisting device, which can be used for assisting the power of joints such as a shoulder joint 61, a wrist joint, and a hip joint. The shoulder joint assist force will be described below as an example.

As shown in fig. 1, 3 and 4, the wearable human joint assist device includes a driving mechanism 1, a cam mechanism 2, a flexible cable assembly 3, a flexible cable guide mechanism 4 and a flexible cable parallel mechanism.

The drive mechanism 1 comprises a rotary output shaft 15 and the cam mechanism 2 comprises a plurality of cams 21-23, each of the plurality of cams 21-23 being mounted on the rotary output shaft 15.

The wire assembly 3 includes a plurality of wires 31-33, the plurality of wires 31-33 correspond to the plurality of cams 21-23, each cam 21/22/23 has a wire 31/32/33 wound thereon, and the plurality of wires 31-33 are guided by the wire guide mechanism 4.

The flexible cable parallel mechanism comprises a fixed platform 51 and a movable platform 52, wherein the fixed platform 51 is arranged to be fixed on the supporting side of a human joint, the movable platform 52 is arranged to be fixed on the force application side of the human joint, the fixed platform 51 is provided with flexible cable through holes 514, and a plurality of flexible cables 31-33 are connected to the movable platform 52 after penetrating through the flexible cable through holes 514 on the fixed platform 51.

In the embodiment of the present application, the plurality of cams 21-23 of the cam gear 2 are fixed to the same rotary output shaft 15, and each cam 21/22/23 has a wire 31/32/33 wound therearound. The plurality of wires 31-33 are arranged in parallel, and the wires 31-33 are guided by the wire guide mechanism 4, pass through the wire through holes 514 on the fixed platform 51 and then are connected to the movable platform 52. Wherein, the fixed platform 51 and the movable platform 52 are respectively fixed on the supporting side and the force application side of the shoulder joint 61 of the human body 6, for example, the fixed platform 51 can be fixed at the position between the shoulder joint 61 and the head, and the movable platform 52 can be fixed on the upper arm 62, so that the flexible cables 31-33 can apply the assistance force to the upper arm 62 through the movable platform 52.

When the driving mechanism 1 works, the rotating output shaft 15 rotates and drives the plurality of cams 21-23 to rotate simultaneously, and the plurality of flexible cables 31-33 on the plurality of cams 21-23 can be wound and unwound simultaneously. By designing the contour lines of the cams 21-23, the flexible cables 31-33 can be always kept in a tensioned state under a certain motion track of the upper arm 62. The flexible cables 31-33 drive the movable platform 52 to move, so as to drive the upper arm 62 to move around the shoulder joint 61, and the assistance of the shoulder joint 61 is realized.

The embodiment of the application provides an under-actuated wearable human joint power assisting device based on a cam and parallel cable structure, only one driving motor 11 is needed to drive a plurality of flexible cables 31-33 to realize the power assisting of a plurality of degrees of freedom of a shoulder joint 61, the number of the driving motors 11 is reduced, the quality, the size and the cost of the device are reduced, and the portability of the device is improved.

In some exemplary embodiments, as shown in FIGS. 1 and 4, three cams 21-23 and three wires 31-33 are provided.

The wearable human body joint power assisting device comprising the three cams 21-23 and the three flexible cables 31-33 can realize power assisting of three degrees of freedom of the shoulder joint 61.

It should be understood that the number of cams and wires may be other than three, such as two or more than three.

In some exemplary embodiments, as shown in FIGS. 1 and 4, the cams 21-23 are provided with grooves 24 around which the wires 31-33 are wound, respectively. The wires 31-33 are respectively wound in the grooves 24 of the cams 21-23, and the wire outlet direction of the wires 31-33 is always tangential to the contour of the groove 24 on the cams 21-23 (referred to as the cam contour for short).

The radius ρ of the contour of the groove 24 on the cams 21-23 (simply referred to as the cam contour) is:

where δ l represents the length of the wire unwound or wound around the cam 21/22/23 when the rotation angle of the cam 21/22/23 is δ θ.

When the wire 31/32/33 is an inelastic wire (i.e., the amount of expansion and contraction deformation of the wire 31/32/33 is negligible), the length of the wire unwound or wound around the cam 21/22/23 is equal to the absolute value of the amount of change in the length of the portion of the wire 31/32/33 corresponding to the cam 21/22/23 located between the fixed platform 51 and the movable platform 52 (referred to simply as the absolute value of the amount of change in the length of the wire).

The distribution mode of the flexible cables 31-33 can be determined according to the prior art, for example, the distribution mode of the flexible cables 31-33 can be determined according to the distribution optimization calculation method of the flexible cables 31-33 in the literature (Mao Y, Agrawal S K.A cable drive upper arm experience for upper experience reproducibility [ C ]// IEEE International Conference on Robotics & Automation. IEEE, 2011.).

The upper arm 62 moves and the movable platform 52 moves with the upper arm 62 so that the lengths of the wires 31-33 between the fixed platform 51 and the movable platform 52 vary. For example, when the arm is lifted (the upper arm 62 is lifted), according to the simulation, the length of the three wires 31-33 can be obtained to change along with the posture of the upper arm 62 as shown in fig. 8, and the action of the upper arm 62 is shown in fig. 14.

If the contour surface of the cam is a complete circle, when the cam rotates by an angle theta, the length delta l of the flexible cable unwound or wound on the cam (namely the rope unwinding amount or the rope winding amount of the cam) is equal to the arc length of the contour line of the cam corresponding to the angle theta. Wherein, when the cam rotates towards one direction (such as clockwise), the flexible cable is unwound from the cam; when the cam rotates in the opposite direction (for example, rotates in the counterclockwise direction), the flexible cable is wound on the cam, and the corresponding relation between the rotation direction of the cam and the releasing and receiving of the cable is related to the winding direction of the flexible cable. Next, the explanation will be given taking an example in which the cam is rotated to unwind the wire.

In practice, the contour of the cams 21-23 is an irregular curve. As can be seen from fig. 10, when the cam 21 having the irregular contour line rotates clockwise by the angle θ, the cam 21 rotates from the state shown by the solid line to the state shown by the broken line, the tangent point of the cam 21 to the wire 31 changes from point P to point Q ', the point P on the contour of the cam 21 shown by the solid line corresponds to the point P ' on the contour of the cam 21 shown by the broken line, and the point Q on the contour of the cam 21 shown by the solid line corresponds to the point Q ' on the contour of the cam 21 shown by the broken line.

When the cam 21 rotates by the angle θ, the length of the wire unwound from the cam 21 is the length corresponding to the curve PQ, and the angle corresponding to the curve is slightly larger than the angle θ, so that the tangent point of the wire 31 and the cam 21 changes with the rotation of the cam 21. Further, since the length of the tangent line between the cam 21 and the guide pulley 432 adjacent to the cam 21 (the pulley wire guide mechanism 4 includes the guide pulley 432, and the detailed description of the wire guide mechanism 4 is described below) is changed, and the tangent point of the guide pulley 432 and the wire 31 is changed, the length Δ l of the unwound wire 31 on the cam 21 is no longer equal to the change amount of the length of the wire 31. Therefore, in practice, the arc length corresponding to the angle θ of the cam 21 is not equal to Δ l.

In order to simplify the calculation, the cam 21 may be divided into a plurality of small δ θ in one rotation, and when the rotation angle of the cam 21 is δ θ, since the tangent point on the cam 21 and the guide wheel 432 adjacent to the cam 21 and the change in the tangent length therebetween are small, the length of the curve in the δ θ angle range of the cam 21 may be regarded as being approximately equal to δ l, and the curve may be regarded as a circular arc to find the corresponding radius ρ, as shown in the above formula (1). Likewise, the contours of the other two cams 22-23) can be derived.

When the flexible cable is an inelastic flexible cable, the cable unwinding amount or the cable winding amount δ l of the cam is an absolute value of a length change amount of a portion of the corresponding flexible cable located between the fixed platform 51 and the movable platform 52. From the variation in the lengths of the three wires 31 to 33 with the attitude of the upper arm 62 shown in fig. 8, it is possible to obtain the shapes shown in fig. 9 as the contour lines of the three cams 21 to 23.

According to the profile of the cams 21-23 shown in fig. 9, the variation of the lengths of the wires 31-33 after the cams 21-23 rotate at a constant speed can be reversely deduced when the cams 21-23 are in the profile.

The amount of change in the length of the wires 31-33 can be modeled in SolidWorks software according to the cams 21-23 shown in FIG. 9. Alternatively, according to fig. 10, the radius of the cam 21 corresponding to the angle τ is p, and the radius of the guide wheel 432 is r_pThe variation of the length of the wire 31 is shown in formula (2). The amount of change in the length of the wires 31-33 can be determined by analytical geometric derivation.

As shown in fig. 11 to 13, the actual variation amount (i.e., the actual curve) of the length variation of the wires 31 to 33 when the cams 21 to 23 rotate is compared with the variation amount (the target curve) of the length of the wires 31 to 33 in fig. 8, so as to obtain the error of the length variation amount of the three wires 31 to 33. The error is within an acceptable range, and the amount of slack caused by the error can be compensated by the deformation of the flexible cable itself.

Therefore, by designing the contour lines of the cams 21 to 23, it is ensured that the wires 31 to 33 are always kept in a tensioned state under a certain motion trajectory of the upper arm 62, and assistance can be provided to the shoulder joint 61.

If it is desired to accurately control the forces on the plurality of wires simultaneously, the wires may be configured as resilient wires (see description of resilient wires below). For the elastic flexible cable, the length of the flexible cable unwound or wound on the cam is determined according to the length variation of the portion of the corresponding flexible cable between the fixed platform and the movable platform and the variation of the elastic deformation of the corresponding flexible cable.

In an exemplary embodiment, the rope releasing or retracting amount δ l of the cam is obtained by subtracting the variation of the elastic deformation of the elastic flexible rope from the variation of the length of the portion of the corresponding elastic flexible rope between the fixed platform 51 and the movable platform 52 (i.e., the variation of the length of the flexible rope). The elastic deformation of the elastic flexible cable is determined by the target force on the flexible cable and Hooke's law. It should be noted that, the variation of the length of the flexible cable and the variation of the elastic deformation of the elastic flexible cable may be positive or negative, such as: when the length of the portion of the wire between the fixed platform 51 and the movable platform 52 is increased, the amount of change in the length of the wire is a positive value; when the length of the portion of the wire between the fixed platform 51 and the movable platform 52 is reduced, the amount of change in the length of the wire is negative. When the elastic deformation (tensile deformation) of the elastic flexible cable increases (i.e., the length of the elastic portion of the elastic flexible cable increases), the amount of change in the elastic deformation of the elastic flexible cable is a positive value; when the elastic deformation of the elastic flexible cable is reduced, the variation of the elastic deformation of the elastic flexible cable is a negative value.

In the wearable human joint power assisting device, the three flexible cables 31-33 can comprise two elastic flexible cables and one inelastic flexible cable, wherein the flexible cable 31 is an inelastic flexible cable, and the flexible cables 32-33 are elastic flexible cables. A simulation schematic diagram of the wearable human joint assist device during arm lifting (e.g., carrying) is shown in fig. 14, a schematic diagram of changes in cable force of the three wires 31-33 is shown in fig. 15, and a schematic diagram of changes in length of the three wires is shown in fig. 8.

From the movement of the arm-raising posture in fig. 14, the target force in the wire in fig. 15, and the change in the wire length between the fixed platform 51 and the movable platform 52 in fig. 8, the profiles of the cams corresponding to the three wires can be calculated similarly from the formula (1) in the above-described method of calculating δ l. The wearable human joint power assisting device is built according to the design and is tested, wherein the planned path and the actual path of the motion trail of the upper arm are shown in fig. 16, and the theoretical value and the actual value of the cable force of the two elastic flexible cables are shown in fig. 17. As can be seen from fig. 16 and 17, the actual force in the wire is close to the target force near the planned path.

As shown in fig. 18, the actual amount of change in the lengths of the three wires 31 to 33 (i.e., the experimental value of the wires 31 to 33 in fig. 18) is compared with the target amount of change in the lengths of the wires 31 to 33 in fig. 8 (i.e., the target value of the wires 31 to 33 in fig. 18), and the error in the amount of change in the lengths of the three wires 31 to 33 is obtained. The error of the non-elastic wire 31 is within an acceptable range, the relaxation amount caused by the error can be compensated by the deformation of the wire, and the error of the elastic wires 32-33 can be compensated by the elastic deformation of the wire.

Therefore, by designing the contour line of the cam corresponding to the elastic wire, it is possible to ensure that the actual force in the elastic wire is close to the target force at a constant motion locus of the upper arm 62, and to provide a predetermined assisting force to the shoulder joint 61.

In some exemplary embodiments, the plurality of cams 21-23 are a unitary structure. As shown in fig. 4, the three cams 21-23 are of a unitary construction.

Of course, the three cams 21-23 may also be three separate cams; or, part cam is the integral type structure, and part cam is independent structure, like: the two cams are of an integrated structure, and the other cam is of an independent structure.

In some exemplary embodiments, the cam 21/22/23 may be formed by 3d printing, and the plurality of cams 21-23 may be printed as a single unit.

In some exemplary embodiments, as shown in FIG. 2, each wire 31/32/33 of the plurality of wires 31-33 is a flexible wire.

In other exemplary embodiments, one of the plurality of wires 31-33 is an inelastic wire and the remaining wires are elastic wires.

The flexible cables are elastically deformable to ensure that the flexible cables remain tensioned and assist the shoulder joint 61 throughout a range of motion of the upper arm 62.

In addition, the elastic deformation and the stress of the elastic flexible cable can satisfy Hooke's law, so that the tensile force on the elastic flexible cable can be controlled through the deformation of the elastic flexible cable. When the plurality of flexible cables 31-33 are elastic flexible cables, the tension on the elastic flexible cables can be controlled through the deformation amount of the elastic flexible cables. One of the plurality of wires 31 to 33 is an inelastic wire, and the other wires are elastic wires, so that the tension of the elastic wires can be controlled by the amount of deformation of the elastic wires, and the tension of the inelastic wires can be controlled by the output torque of the driving motor 11.

In some exemplary embodiments, as shown in FIG. 2, the elastic wires comprise a first non-elastic wire 34 and a second elastic wire 35, the first wire 34 and the second wire 35 being connected in series. For the elastic flexible cable, the variation of the elastic deformation of the flexible cable mainly refers to the variation of the elastic deformation of the second flexible cable 35.

As shown in FIG. 2, one end of the first wire 34 is wound around the cams 21-23, the other end of the first wire 34 is connected to one end of the second wire 35, the other end of the second wire 35 is connected to the movable platform 52, and the second wire 35 is located between the fixed platform 51 and the movable platform 52.

It should be understood that the second wire 35 may be disposed at other positions, for example, the second wire 35 may be disposed at the middle of the elastic wire and may be disposed between the cam 21/22/23 and the guide wheel 432 of the adjacent cam, or between the adjacent guide wheels 432 of the wire guide mechanism 4, etc.

In some exemplary embodiments, as shown in FIG. 2, the first wire 34 may comprise a cord. It should be understood that the first flexible cable 34 may be in other forms than a rope, such as a wire rope, a chain, etc.

In some exemplary embodiments, as shown in FIG. 2, the second wire 35 may comprise a spring. It should be understood that the second wire 35 may be in other forms than a spring, such as a rubber band. The elastic deformation and the stress of the second flexible cable 35 satisfy hooke's law.

It should be understood that the elastic flexible cable in the embodiment of the present application has flexibility as a whole, but the elastic portion of the elastic flexible cable, such as the second flexible cable 35, may have elasticity and flexibility (such as rubber band), or only elasticity (such as spring, etc.).

In some exemplary embodiments, as shown in fig. 1 and 7, the wire guide mechanism 4 comprises at least one wire guide mechanism set, each wire guide mechanism set is used for guiding one or more wires 31-33, each wire guide mechanism set comprises at least one guide wheel assembly 43, the guide wheel assembly 43 comprises a support base 431 and at least one guide wheel 432 mounted on the support base 431, and the wires 31-33 are wound around the guide wheel 432.

The wire guide 4 is used to guide the wires 31-33 tangential to the contour of the cams 21-23 to the fixed platform 51 of the wire parallel mechanism. The at least one guide wheel assembly 43 of the set of wire guide mechanisms may be arranged in sequence between the cam mechanism 2 and the fixed platform 51, and the wires 31-33 are passed in sequence around the guide wheels 432 of the at least one guide wheel assembly 43 comprised by the set of wire guide mechanisms for guiding the wires 31-33.

In some exemplary embodiments, as shown in fig. 7, the guide wheel assembly 43 may further include a mounting shaft 433, and the guide wheel 432 may be rotatably mounted on the supporting seat 431 by the mounting shaft 433.

When the cams 21 to 23 rotate and the flexible cables 31 to 33 are retracted, the guide wheel 432 rotates, so that the flexible cables 31 to 33 can be retracted conveniently.

In some exemplary embodiments, as shown in fig. 1, the wire guide mechanism 4 includes two wire guide mechanism sets, a first wire guide mechanism set 41 and a second wire guide mechanism set 42. The first wire guide mechanism group 41 is used for guiding one wire 31, and a guide wheel 432 is installed on the supporting seat 431 of the guide wheel assembly 43 of the first wire guide mechanism group 41; the second wire guiding mechanism set 42 is used for guiding the two wires 32-33, and two guide wheels 432 are mounted on the supporting base 431 of the guide wheel assembly 43 of the second wire guiding mechanism set 42.

As shown in fig. 1, the first wire guide mechanism set 41 may include one (or another number) of guide wheel assemblies 43, the guide wheel assemblies 43 being used to guide one wire 31. The second wire guiding mechanism set 42 may comprise five (or another number) of guide wheel assemblies 43, one wire 32 passing through one guide wheel 432 of the five guide wheel assemblies 43 in turn, and the other wire 33 passing through one guide wheel 432 of the five guide wheel assemblies 43 in turn, to achieve guiding of the two wires 31-33.

Of course, two guide wheels 432 may be installed on the supporting seat 431 of the guide wheel assembly 43 of the first wire guide mechanism group 41, so that the guide wheel assemblies 43 in the first wire guide mechanism group 41 and the second wire guide mechanism group 42 have the same structure, which facilitates the processing of the guide wheel assemblies 43 and the assembly of the wire guide mechanisms 4.

It will be appreciated that the number and spatial arrangement of the guide wheel assemblies 43 in the wire guide mechanism 4 may be varied to meet different guiding requirements.

In some exemplary embodiments, as shown in fig. 5, the fixed platform 51 includes a fixed mounting base 511, a plurality of cord brackets 512, and a plurality of sheep-eye nails 513, wherein the plurality of cord brackets 512 are fixed on the fixed mounting base 511, the plurality of sheep-eye nails 513 are respectively fixed on the plurality of cord brackets 512, and the sheep-eye nails 513 are provided with cord through holes 514.

As shown in fig. 1 and 5, the fixed mount 511 may have a semi-annular shape and be fixed in position between the shoulder joint 61 and the head. The fixing mount 511 may be made of metal, such as aluminum alloy. The inner side of the fixed mounting seat 511 may be provided with a first flexible cushion 516, and the first flexible cushion 516 may be a flexible air cushion and may be adhered and fixed with the fixed mounting seat 511. The first flexible mat 516 may be in contact with the human body 6. The wire support 512 can be fixed on the fixing mount 511 by screws 515, and the fixing mount 511 and the wire support 512 are provided with screw fixing holes. The sheep-eye nail 513 can be fixed on the flexible cable bracket 512 through a self-tapping screw, and a flexible cable through hole 514 is arranged on the sheep-eye nail 513 to play a role in guiding the flexible cables 31-33.

As shown in fig. 1 and 5, the fixing platform 5 may include two sheep-eye nails 513, a wire through hole 514 of one sheep-eye nail 513 for passing one wire 31, and a wire through hole 514 of the other sheep-eye nail 513 for passing two wires 32-33.

In some exemplary embodiments, as shown in fig. 1 and 6, the movable platform 52 includes a movable mounting base 521, a plurality of fixing holes 522 are formed on the movable mounting base 521, and the plurality of wires 31-33 respectively pass through the plurality of fixing holes 522 and are fixed.

As shown in fig. 1 and 6, the movable mount 521 may have a ring shape (or other shape, such as a semi-ring shape) and be fixed to the upper arm 62 of the human body 6. The movable mount 521 may be made of metal, such as aluminum alloy. The inner side of the movable mounting base 521 is provided with a second flexible cushion 524, and the second flexible cushion 524 may be a flexible air cushion and may be fixed to the movable mounting base 521 by bonding. The second flexible pad 524 is in contact with the upper arm 62. Three fixing holes 522 are formed in the movable mounting base 521, and the flexible cables 31 to 33 are fixed through the three fixing holes 522. The three fixing holes 522 are uniformly or non-uniformly arranged in the circumferential direction of the movable mount 521. The movable mounting base 521 is hollowed out to form lightening holes 523, so as to reduce the weight while maintaining the rigidity of the movable mounting base 521.

In some exemplary embodiments, as shown in fig. 1 and 3, the driving mechanism further includes a driving motor 11 and a reduction gearbox 12, an encoder 14 and a coupling 13, wherein the reduction gearbox 12 may be a gear reduction gearbox, and a driving motor shaft of the driving motor 11 is coaxial with a rotating output shaft 15 of the driving mechanism. The driving mechanism 1 and the cam mechanism 2 can be assembled together and fixed on the back of the human body 6.

In some exemplary embodiments, an IMU (inertial measurement unit) is provided on the upper arm 62.

The IMU can know the posture of the upper arm 62, and further know that the flexible cables 31-33 need to be retracted or extended, and further control the driving motor 11 to rotate forwards or reversely.

In some exemplary embodiments, force sensors may be provided on the wires 31-33 to measure the tension on the wires 31-33.

The above examples only express exemplary embodiments of the present application, and the description thereof is more specific and detailed, but the contents are only the embodiments adopted for understanding the present application, and are not intended to limit the present application. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.

Claims

1. A wearable human joint power assist device, comprising:

a drive mechanism including a rotary output shaft;

2. The wearable human joint power-assisted device of claim 1, wherein the cam is provided with a groove for winding the wire, and the radius ρ of the contour line of the groove is:

wherein δ l represents the length of the flexible cable unwound or wound on the cam when the rotation angle of the cam is δ θ;

when the flexible cable is an inelastic flexible cable, the length of the flexible cable unwound or wound on the cam is equal to the absolute value of the length variation of the part, located between the fixed platform and the movable platform, of the corresponding flexible cable; when the flexible cable is an elastic flexible cable, the length of the unwound or wound flexible cable on the cam is determined according to the length variation of the part, located between the fixed platform and the movable platform, of the corresponding flexible cable and the variation of elastic deformation of the corresponding flexible cable.

3. The wearable human joint assistance device of claim 1, wherein the plurality of cams are of a unitary construction.

4. The wearable human joint assistance device of any one of claims 1 to 3, wherein each of the plurality of wires is a resilient wire;

or, in the plurality of flexible cables, one flexible cable is an inelastic flexible cable, and the other flexible cables are elastic flexible cables.

5. The wearable human joint assistance device of claim 4, wherein the elastic wires comprise a first inelastic wire and a second elastic wire, the first wire connected in series with the second wire.

6. The wearable human joint power assisting device according to any one of claims 1 to 3, wherein the fixing platform comprises a fixing mounting seat, a plurality of cord brackets and a plurality of sheep eye nails, the cord brackets are all fixed on the fixing mounting seat, the sheep eye nails are respectively fixed on the cord brackets, and the sheep eye nails are provided with the cord through holes.

7. The wearable human joint power assisting device according to any one of claims 1 to 3, wherein the movable platform comprises a movable mounting base, a plurality of fixing holes are formed in the movable mounting base, the plurality of fixing holes correspond to the plurality of flexible cables one to one, and the plurality of flexible cables respectively penetrate through the plurality of fixing holes and are fixed.

8. The wearable human joint power assist device of claim 7, wherein the movable mount is annular or semi-annular, and the plurality of fixing holes are uniformly or non-uniformly arranged along a circumferential direction of the movable mount.

9. The wearable human joint assistance device of any one of claims 1-3, wherein the wire guide mechanism comprises at least one set of wire guide mechanisms, each set of wire guide mechanisms for guiding one or more wires,

each flexible cable guide mechanism group comprises at least one guide wheel assembly, each guide wheel assembly comprises a supporting seat and at least one guide wheel installed on the supporting seat, and the flexible cables are wound around the guide wheels.

10. The wearable human joint assistance device of claim 9, wherein there are three of the cam and the wires, wherein the wire guide mechanism comprises two wire guide mechanism sets, a first wire guide mechanism set and a second wire guide mechanism set,

the first flexible cable guide mechanism group is used for guiding one flexible cable, and the supporting seat of the guide wheel assembly of the first flexible cable guide mechanism group is provided with one guide wheel;

the second flexible cable guide mechanism group is used for guiding two flexible cables, and two guide wheels are installed on a supporting seat of the guide wheel assembly of the second flexible cable guide mechanism group.