CN117621138A - Six-degree-of-freedom mechanical arm tail end passive softening device based on permanent magnet arrangement - Google Patents

Abstract

The invention discloses a six-degree-of-freedom mechanical arm tail end passive compliance device based on permanent magnet arrangement, which realizes impedance along the z direction through a first axial permanent magnet assembly and a second axial permanent magnet assembly which are opposite in axial interval; impedance along the x/y direction and around the x/y direction is achieved by a radial permanent magnet assembly that generates a radial repulsive force; impedance around the z-direction is achieved by a radial permanent magnet assembly that generates radial attraction forces; meanwhile, the impedance along the z direction can be changed by adjusting the distance between the first permanent magnet assembly and the second axial permanent magnet assembly and the number of the permanent magnets; the resistance in the x/y direction, the x/y direction and the z direction is changed by adjusting the thickness, the number of mounting of permanent magnets in the radial permanent magnet assembly generating the radial repulsive force or the radial attractive force, and the outer diameter size of the inner ring magnetic pole group or the inner diameter size of the outer ring magnetic pole group. The invention has the advantages of compact structure, convenient disassembly, assembly and replacement, flexible impedance adjustment and wide application range.

Description

Six-degree-of-freedom mechanical arm tail end passive softening device based on permanent magnet arrangement

Technical Field

The invention relates to the technical field of mechanical arms, in particular to a six-degree-of-freedom mechanical arm tail end passive softening device based on permanent magnet arrangement.

Background

The existing passive compliant device applied to the autonomous assembly of the mechanical arm is composed of parallel springs, dampers or rubber materials, and the compliant contact effect of the tail end of the mechanical arm when the tail end of the mechanical arm contacts with the outside is achieved through the rigidity or damping of the passive compliant device. On the basis, the flexible degree (the larger the impedance is, the smaller the flexibility) of the passive compliance device can be changed by adjusting the initial state of the spring or the rubber material. However, the impedance of each degree of freedom of the structure is flexibly related to the parallel elements, and the parallel elements are highly coupled, so that independent adjustment of the respective degrees of freedom cannot be performed.

Disclosure of Invention

The purpose of the invention is that: the passive flexible device of six-degree-of-freedom mechanical arm tail end based on permanent magnet arrangement not only can realize six-degree-of-freedom flexible contact between the mechanical arm tail end and the outside, but also can independently change the flexible size of each degree of freedom by designing and adjusting the number, the arrangement interval, the size and the like of the permanent magnets.

In order to achieve the above purpose, the present invention adopts the following scheme:

the passive compliance device of the tail end of the six-degree-of-freedom mechanical arm based on permanent magnet arrangement comprises a shell, a movable shaft, a first axial permanent magnet assembly, a second axial permanent magnet assembly and a plurality of groups of radial permanent magnet assemblies; one end of the shell is provided with a mounting end plate, and the other end of the shell is provided with an end cover plate; the first axial permanent magnet assembly, the second axial permanent magnet assembly and the plurality of groups of radial permanent magnet assemblies are sequentially arranged in the shell along the axial direction; the first axial permanent magnet assembly is fixed on the mounting end plate, and the second axial permanent magnet assembly and the first axial permanent magnet assembly are arranged at opposite intervals; the movable shaft penetrates through the end cover plate to be movably inserted into the shell and is connected with the second axial permanent magnet assembly, and a first movable space is reserved between the periphery of the second axial permanent magnet assembly and the inner wall of the shell; an axial repulsive force is generated between the first axial permanent magnet assembly and the second axial permanent magnet assembly; each radial permanent magnet assembly is provided with an inner ring magnetic pole group and an outer ring magnetic pole group, and the outer ring magnetic pole groups are fixed in the shell in a matching way and are arranged on the periphery of the inner ring magnetic pole groups in a surrounding way; the inner ring magnetic pole group is sleeved on the movable shaft, and a second movable space is reserved between the outer periphery of the inner ring magnetic pole group and the inner periphery of the outer ring magnetic pole group; a radial repulsive force or a radial attractive force is generated between the inner ring magnetic pole group and the outer ring magnetic pole group; among the plurality of groups of radial permanent magnet assemblies, the radial permanent magnet assemblies generating radial repulsive force and the radial permanent magnet assemblies generating radial attractive force are alternately arranged.

As a preferable scheme of the invention, the radial permanent magnet assembly is provided with 3 groups, namely a first radial permanent magnet assembly, a second radial permanent magnet assembly and a third radial permanent magnet assembly, the second radial permanent magnet assembly is arranged between the first radial permanent magnet assembly and the third radial permanent magnet assembly, and a radial repulsive force is generated between an inner ring magnetic pole group of the first radial permanent magnet assembly and an outer ring magnetic pole group of the first radial permanent magnet assembly; radial suction force is generated between the inner ring magnetic pole group of the second radial permanent magnet assembly and the outer ring magnetic pole group of the second radial permanent magnet assembly; and a radial repulsive force is generated between the inner ring magnetic pole group of the third radial permanent magnet assembly and the outer ring magnetic pole group of the third radial permanent magnet assembly.

As a preferred aspect of the present invention, the first axial permanent magnet assembly includes a first axial planar panel connected to the mounting end plate and a plurality of first circular permanent magnets embedded on the first axial planar panel, the plurality of first circular permanent magnets being uniformly arranged along a circumferential direction of the first axial planar panel; the second axial permanent magnet assembly comprises a second axial planar panel connected with the movable shaft and a plurality of second circular permanent magnets embedded on the second axial planar panel, and the second circular permanent magnets are uniformly arranged along the circumferential direction of the second axial planar panel; the number of the first circular permanent magnets is the same as the number of the second circular permanent magnets; the magnetic poles of the first circular permanent magnet and the second circular permanent magnet which are opposite are the same.

As a preferable mode of the invention, a first back iron is arranged on the surface of the first axial plane-shaped panel, which is close to one side of the installation end plate; and a second back iron is arranged on the surface of the second axial plane-shaped panel, which is close to one side of the movable shaft.

As a preferable mode of the invention, the inner ring magnetic pole group comprises a first radial annular panel sleeved with the movable shaft and a plurality of first square permanent magnets embedded on the first radial annular panel, and the plurality of first square permanent magnets are uniformly arranged along the circumferential direction of the first radial annular panel; the outer ring magnetic pole group comprises a second radial annular panel and a plurality of second square permanent magnets, the second radial annular panel is connected with the shell in a matched mode, the second square permanent magnets are embedded on the second radial annular panel, and the second square permanent magnets are uniformly arranged along the circumferential direction of the second radial annular panel; the number of the first square permanent magnets is the same as the number of the second square permanent magnets; in the radial permanent magnet assembly generating the radial repulsive force, the magnetic poles of the first square permanent magnet and the second square permanent magnet which are opposite are the same; in the radial permanent magnet assembly generating radial attraction force, the magnetic poles of the first square permanent magnet and the magnetic poles of the second square permanent magnet are opposite.

As a preferable scheme of the invention, the shell is composed of a first shell and a second shell, one end of the first shell is detachably connected with one end of the second shell, the other end of the first shell is integrally formed with the mounting end plate, and the other end of the second shell is detachably connected with the end cover plate.

As a preferable scheme of the invention, the first shell is provided with a first end face flange, the second shell is provided with a second end face flange matched with the first end face flange, and the first end face flange and the second end face flange are fixedly connected through a bolt and nut pair; the second shell is provided with a third end face flange, and the third end face flange is fixedly connected with the end cover plate through a bolt and nut pair.

As a preferable mode of the invention, the end part of the second shell, which faces the first shell, is provided with a convex ring, and the convex ring extends into the port of the first shell and is matched with the port.

As a preferred aspect of the present invention, when the end cover plate is covered on the second housing, the end cover plate presses the plurality of sets of radial permanent magnet assemblies against the convex ring.

As a preferable scheme of the invention, a first positioning sleeve is sleeved on the movable shaft, one end of the first positioning sleeve is propped against the second axial permanent magnet assembly, and the other end of the first positioning sleeve is propped against the inner ring magnetic pole group close to one side of the first shell; the movable shaft is sleeved with a second positioning sleeve, one end of the second positioning sleeve is propped against the inner ring magnetic pole group far away from one side of the first shell, and the other end of the second positioning sleeve is propped against the shaft shoulder of the movable shaft.

Compared with the prior art, the six-degree-of-freedom mechanical arm tail end passive softening device based on permanent magnet arrangement has the beneficial effects that:

the passive compliance device realizes impedance along the z direction through the first axial permanent magnet component and the second axial permanent magnet component which are axially spaced and opposite; impedance along the x/y direction and around the x/y direction is achieved by a radial permanent magnet assembly that generates a radial repulsive force; impedance around the z-direction is achieved by a radial permanent magnet assembly that generates radial attraction forces; meanwhile, the passive compliance device can change the impedance along the z direction (the larger the impedance, the smaller the flexibility) by adjusting the distance between the first axial permanent magnet assembly and the second axial permanent magnet assembly and the number of the permanent magnets in the axial permanent magnet assemblies; changing the resistance in the x/y direction and the winding x/y direction by adjusting the thickness, the number of installation, and the outer diameter size of the inner ring magnetic pole group or the inner diameter size of the outer ring magnetic pole group of the permanent magnets in the radial permanent magnet assembly generating the radial repulsive force; the resistance in the z direction is changed by adjusting the thickness, the number of installation, and the outer diameter size of the inner ring magnetic pole group or the inner diameter size of the outer ring magnetic pole group of the permanent magnet in the radial permanent magnet assembly generating the radial attraction force.

In summary, the passive flexible device can realize six-degree flexible contact between the tail end of the mechanical arm and the outside, and can independently change the flexibility of each degree of freedom by designing and adjusting the number, the arrangement interval, the size and the like of the permanent magnets, and has the advantages of compact structure, convenient disassembly, assembly and replacement, flexible impedance adjustment and wide application range.

Drawings

FIG. 1 is an isometric view of a six degree of freedom mechanical arm end passive compliance device based on permanent magnet arrangement in accordance with an embodiment of the present invention;

FIG. 2 is a front view of a six degree of freedom mechanical arm end passive compliance device based on a permanent magnet arrangement in accordance with an embodiment of the present invention;

FIG. 3 is a cross-sectional view taken in the direction A-A of the structure shown in FIG. 2;

FIG. 4 is a cross-sectional view taken in the direction B-B of the structure shown in FIG. 2;

fig. 5 is a cross-sectional view in the direction C-C of the structure shown in fig. 2.

Reference numerals:

a housing 1; a first housing 1a; a second housing 1b; mounting an end plate 101; an end cover plate 102; a first end face flange 103; a second end flange 104; a third end face flange 105; a collar 106; a movable shaft 2; a first axial permanent magnet assembly 3; a first axial planar panel 301; a first circular permanent magnet 302; a first back iron 303; a second axial permanent magnet assembly 4; a second axial planar panel 401; a second circular permanent magnet 402; a second back iron 403; a radial permanent magnet assembly 5; a first radial permanent magnet assembly 5a; a second radial permanent magnet assembly 5b; a third radial permanent magnet assembly 5c; an inner ring magnetic pole group 51; a first radial annular panel 511; a first square permanent magnet 512; an outer ring magnetic pole group 52; a second radial annular panel 521; a second square permanent magnet 522; a first movable space 6; a second movable space 7; a first positioning sleeve 8; a second positioning sleeve 9.

Detailed Description

The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.

In the description of the present invention, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present invention and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, a number means one or more, a number means two or more, and greater than, less than, exceeding, etc. are understood to not include the present number, and above, below, within, etc. are understood to include the present number. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present invention can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.

As shown in fig. 1 to 5, the six-degree-of-freedom mechanical arm end passive compliance device based on permanent magnet arrangement provided by the embodiment of the invention comprises a shell 1, a movable shaft 2, a first axial permanent magnet assembly 3, a second axial permanent magnet assembly 4 and a plurality of groups of radial permanent magnet assemblies 5; one end of the shell 1 is provided with a mounting end plate 101, and the other end of the shell 1 is provided with an end cover plate 102; the first axial permanent magnet assembly 3, the second axial permanent magnet assembly 4 and the plurality of groups of radial permanent magnet assemblies 5 are sequentially arranged in the shell 1 along the axial direction; the first axial permanent magnet assembly 3 is fixed on the mounting end plate 101, and the second axial permanent magnet assembly 4 and the first axial permanent magnet assembly 3 are arranged at opposite intervals; the movable shaft 2 is movably inserted into the shell 1 through the end cover plate 102 and is connected with the second axial permanent magnet assembly 4, and a first movable space 6 is reserved between the outer periphery of the second axial permanent magnet assembly 4 and the inner wall of the shell 1; an axial repulsive force is generated between the first axial permanent magnet assembly 3 and the second axial permanent magnet assembly 4; each radial permanent magnet assembly 5 is provided with an inner ring magnetic pole group 51 and an outer ring magnetic pole group 52, and the outer ring magnetic pole groups 52 are fixed in the shell 1 in a matching way and are arranged on the periphery of the inner ring magnetic pole groups 51 in a surrounding way; the inner ring magnetic pole group 51 is sleeved on the movable shaft 2, and a second movable space 7 is reserved between the outer periphery of the inner ring magnetic pole group 51 and the inner periphery of the outer ring magnetic pole group 52; a radial repulsive force or a radial attractive force is generated between the inner ring magnetic pole group 51 and the outer ring magnetic pole group 52; among the plurality of groups of radial permanent magnet assemblies 5, radial permanent magnet assemblies 5 generating a radial repulsive force are alternately arranged with radial permanent magnet assemblies 5 generating a radial attractive force.

Therefore, the six-degree-of-freedom mechanical arm tail end passive softening device based on permanent magnet arrangement realizes impedance along the z direction through the first axial permanent magnet assembly 3 and the second axial permanent magnet assembly 4 which are axially spaced and opposite; impedance in the x/y direction and around the x/y direction is achieved by the radial permanent magnet assembly 5 generating a radial repulsive force; impedance around the z-direction is achieved by a radial permanent magnet assembly 5 that generates radial attraction force; meanwhile, the passive compliance device of the present invention can change the magnitude of the resistance in the z direction (the greater the resistance, the less the flexibility) by adjusting the distance between the first axial permanent magnet assembly 3 and the second axial permanent magnet assembly 4 and the number of permanent magnets in the axial permanent magnet assemblies; the resistance in the x/y direction and the around x/y direction is changed by adjusting the thickness, the number of mounting, and the outer diameter size of the inner ring magnetic pole group 51 or the inner diameter size of the outer ring magnetic pole group 52 of the permanent magnets in the radial permanent magnet assembly 5 generating the radial repulsive force; the magnitude of the resistance around the z-direction is changed by adjusting the thickness, the number of mounting, and the outer diameter dimension of the inner ring magnetic pole group 51 or the inner diameter dimension of the outer ring magnetic pole group 52 of the permanent magnets in the radial permanent magnet assembly 5 that generates the radial attraction force.

As shown in fig. 3, the radial permanent magnet assembly 5 is provided with 3 groups, namely a first radial permanent magnet assembly 5a, a second radial permanent magnet assembly 5b and a third radial permanent magnet assembly 5c, wherein the second radial permanent magnet assembly 5b is arranged between the first radial permanent magnet assembly 5a and the third radial permanent magnet assembly 5c, and a radial repulsive force is generated between an inner ring magnetic pole group 51 of the first radial permanent magnet assembly 5a and an outer ring magnetic pole group 52 of the first radial permanent magnet assembly 5a; radial suction force is generated between the inner ring magnetic pole group 51 of the second radial permanent magnet assembly 5b and the outer ring magnetic pole group 52 of the second radial permanent magnet assembly 5b; a radial repulsive force is generated between the inner ring magnetic pole group 51 of the third radial permanent magnet assembly 5c and the outer ring magnetic pole group 52 of the third radial permanent magnet assembly 5 c. Under the same permanent magnet brands and numbers, the thickness of the permanent magnet in the first radial permanent magnet assembly 5a is equal to the thickness of the permanent magnet in the third radial permanent magnet assembly 5c, and the thickness of the permanent magnet in the second radial permanent magnet assembly 5b is equal to the sum of the thickness of the permanent magnet in the first radial permanent magnet assembly 5a and the thickness of the permanent magnet in the third radial permanent magnet assembly 5 c. By means of the design, the movable shaft 2 can be guaranteed to be always in a stress balance state under the combined action of repulsive force and attractive force, and the radial permanent magnet assembly 5 can provide stable impedance when the movable shaft 2 is acted by external force.

Illustratively, in order to facilitate adjustment of the number and number of permanent magnets in the axial permanent magnet assembly, the first axial permanent magnet assembly 3 includes a first axial planar panel 301 connected to the mounting end plate 101, and a plurality of first circular permanent magnets 302 embedded on the first axial planar panel 301, where the plurality of first circular permanent magnets 302 are uniformly arranged along the circumferential direction of the first axial planar panel 301; the second axial permanent magnet assembly 4 includes a second axial planar panel 401 connected to the movable shaft 2 and a plurality of second circular permanent magnets 402 embedded on the second axial planar panel 401, the plurality of second circular permanent magnets 402 being uniformly arranged along a circumferential direction of the second axial planar panel 401; the number of first circular permanent magnets 302 is the same as the number of second circular permanent magnets 402; the first circular permanent magnet 302 has the same magnetic polarity as the second circular permanent magnet 402. The number of the grooves to be fitted in the first axial plane panel 301 and the second axial plane panel 401 may be greater than or equal to the actual number of the first circular permanent magnets 302 and the second circular permanent magnets 402.

Illustratively, in order to prevent the magnetic leakage phenomenon of the axial permanent magnet assembly, a first back iron 303 is disposed on a surface of the first axial planar panel 301 adjacent to one side of the mounting end plate 101; the second axial plane panel 401 is provided with a second back iron 403 on a surface thereof adjacent to the movable shaft 2 side.

Illustratively, for convenience in adjusting the number and number of the permanent magnets in the radial permanent magnet assembly 5, the inner ring magnetic pole group 51 includes a first radial annular panel 511 sleeved with the movable shaft 2, and a plurality of first square permanent magnets 512 embedded on the first radial annular panel 511, and the plurality of first square permanent magnets 512 are uniformly arranged along the circumferential direction of the first radial annular panel 511; the outer ring magnetic pole group 52 comprises a second radial annular panel 521 which is in fit connection with the housing 1, and a plurality of second square permanent magnets 522 which are embedded on the second radial annular panel 521, wherein the plurality of second square permanent magnets 522 are uniformly arranged along the circumferential direction of the second radial annular panel 521; the number of the first square permanent magnets 512 is the same as the number of the second square permanent magnets 522; in the radial permanent magnet assembly 5 generating the radial repulsive force, the first square permanent magnet 512 has the same magnetic pole as the second square permanent magnet 522; in the radial permanent magnet assembly 5 generating radial attraction force, the first square permanent magnet 512 is opposite to the second square permanent magnet 522 in the opposite poles. The number of the grooves formed in the first radial annular panel 511 and the second radial annular panel 521 may be greater than or equal to the actual number of the first square permanent magnets 512 and the second square permanent magnets 522.

Illustratively, for easy disassembly and replacement of the axial permanent magnet assembly and the radial permanent magnet assembly 5, the housing 1 is composed of a first housing 1a and a second housing 1b, one end of the first housing 1a is detachably connected with one end of the second housing 1b, the other end of the first housing 1a is integrally formed with the mounting end plate 101, and the other end of the second housing 1b is detachably connected with the end plate 102. In specific implementation, the first housing 1a is provided with a first end face flange 103, the second housing 1b is provided with a second end face flange 104 matched with the first end face flange 103, and the first end face flange 103 and the second end face flange 104 are fixedly connected through a bolt and nut pair; the second casing 1b is provided with a third end face flange 105, and the third end face flange 105 is fixedly connected with the end cover plate 102 through a bolt and nut pair. Further, a convex ring 106 is provided at the end of the second housing 1b facing the first housing 1a, and the convex ring 106 extends into and cooperates with the port of the first housing 1a, so as to facilitate positioning and mounting of the first housing 1a and the second housing 1 b. And, when the end cover plate 102 is covered on the second casing 1b, the end cover plate 102 can press multiple groups of radial permanent magnet assemblies 5 against the convex ring 106, so as to realize rapid and fixed installation of multiple groups of radial permanent magnet assemblies 5.

Illustratively, a first positioning sleeve 8 is sleeved on the movable shaft 2, one end of the first positioning sleeve 8 abuts against the second axial permanent magnet assembly 4, and the other end of the first positioning sleeve 8 abuts against the inner ring magnetic pole group 51 near one side of the first casing 1a; the movable shaft 2 is sleeved with a second positioning sleeve 9, one end of the second positioning sleeve 9 abuts against the inner ring magnetic pole group 51 far away from one side of the first shell 1a, and the other end of the second positioning sleeve 9 abuts against a shaft shoulder of the movable shaft 2. Such a design enables to modify the distance between the first axial permanent magnet assembly 3 and the second axial permanent magnet assembly 4 by adjusting the dimensions of the first positioning sleeve 8 and the second positioning sleeve 9.

In summary, the passive flexible device provided by the embodiment of the invention not only can realize six automatic flexible contacts between the tail end of the mechanical arm and the outside, but also can independently change the flexible size of each degree of freedom by designing and adjusting the number, the arrangement interval, the size and the like of the permanent magnets, and has the advantages of compact structure, convenience in disassembly, assembly and replacement, flexible impedance adjustment and wide application range.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. The passive compliance device of the tail end of the six-degree-of-freedom mechanical arm based on permanent magnet arrangement comprises a shell, a movable shaft, a first axial permanent magnet assembly, a second axial permanent magnet assembly and a plurality of groups of radial permanent magnet assemblies; one end of the shell is provided with a mounting end plate, and the other end of the shell is provided with an end cover plate; the first axial permanent magnet assembly, the second axial permanent magnet assembly and the plurality of groups of radial permanent magnet assemblies are sequentially arranged in the shell along the axial direction;

the first axial permanent magnet assembly is fixed on the mounting end plate, and the second axial permanent magnet assembly and the first axial permanent magnet assembly are arranged at opposite intervals; the movable shaft penetrates through the end cover plate to be movably inserted into the shell and is connected with the second axial permanent magnet assembly, and a first movable space is reserved between the periphery of the second axial permanent magnet assembly and the inner wall of the shell; an axial repulsive force is generated between the first axial permanent magnet assembly and the second axial permanent magnet assembly;

each radial permanent magnet assembly is provided with an inner ring magnetic pole group and an outer ring magnetic pole group, and the outer ring magnetic pole groups are fixed in the shell in a matching way and are arranged on the periphery of the inner ring magnetic pole groups in a surrounding way; the inner ring magnetic pole group is sleeved on the movable shaft, and a second movable space is reserved between the outer periphery of the inner ring magnetic pole group and the inner periphery of the outer ring magnetic pole group; a radial repulsive force or a radial attractive force is generated between the inner ring magnetic pole group and the outer ring magnetic pole group; among the plurality of groups of radial permanent magnet assemblies, the radial permanent magnet assemblies generating radial repulsive force and the radial permanent magnet assemblies generating radial attractive force are alternately arranged.

2. The six-degree-of-freedom mechanical arm tail end passive softening device based on permanent magnet arrangement according to claim 1, wherein the radial permanent magnet assemblies are provided with 3 groups, namely a first radial permanent magnet assembly, a second radial permanent magnet assembly and a third radial permanent magnet assembly, the second radial permanent magnet assembly is arranged between the first radial permanent magnet assembly and the third radial permanent magnet assembly, and a radial repulsive force is generated between an inner ring magnetic pole group of the first radial permanent magnet assembly and an outer ring magnetic pole group of the first radial permanent magnet assembly; radial suction force is generated between the inner ring magnetic pole group of the second radial permanent magnet assembly and the outer ring magnetic pole group of the second radial permanent magnet assembly; and a radial repulsive force is generated between the inner ring magnetic pole group of the third radial permanent magnet assembly and the outer ring magnetic pole group of the third radial permanent magnet assembly.

3. The six degree of freedom mechanical arm end passive compliance device based on permanent magnet arrangement of claim 1, wherein the first axial permanent magnet assembly comprises a first axial planar panel connected with the mounting end plate and a plurality of first circular permanent magnets embedded on the first axial planar panel, the plurality of first circular permanent magnets being uniformly arranged along a circumferential direction of the first axial planar panel; the second axial permanent magnet assembly comprises a second axial planar panel connected with the movable shaft and a plurality of second circular permanent magnets embedded on the second axial planar panel, and the second circular permanent magnets are uniformly arranged along the circumferential direction of the second axial planar panel; the number of the first circular permanent magnets is the same as the number of the second circular permanent magnets; the magnetic poles of the first circular permanent magnet and the second circular permanent magnet which are opposite are the same.

4. The passive compliance device of a six degree of freedom mechanical arm tip based on permanent magnet arrangement of claim 3, wherein a first back iron is provided on a surface of the first axial planar panel adjacent to one side of the mounting end plate; and a second back iron is arranged on the surface of the second axial plane-shaped panel, which is close to one side of the movable shaft.

5. The six-degree-of-freedom mechanical arm end passive softening device based on permanent magnet arrangement according to claim 1, wherein the inner ring magnetic pole group comprises a first radial annular panel sleeved with the movable shaft and a plurality of first square permanent magnets embedded on the first radial annular panel, and the plurality of first square permanent magnets are uniformly arranged along the circumferential direction of the first radial annular panel; the outer ring magnetic pole group comprises a second radial annular panel and a plurality of second square permanent magnets, the second radial annular panel is connected with the shell in a matched mode, the second square permanent magnets are embedded on the second radial annular panel, and the second square permanent magnets are uniformly arranged along the circumferential direction of the second radial annular panel; the number of the first square permanent magnets is the same as the number of the second square permanent magnets; in the radial permanent magnet assembly generating the radial repulsive force, the magnetic poles of the first square permanent magnet and the second square permanent magnet which are opposite are the same; in the radial permanent magnet assembly generating radial attraction force, the magnetic poles of the first square permanent magnet and the magnetic poles of the second square permanent magnet are opposite.

6. The passive compliance device of six degrees of freedom arm end based on permanent magnetism arrangement according to claim 1, wherein the housing is composed of a first housing and a second housing, one end of the first housing is detachably connected with one end of the second housing, the other end of the first housing is integrally formed with the mounting end plate, and the other end of the second housing is detachably connected with the end cover plate.

7. The passive compliance device of the six-degree-of-freedom mechanical arm tail end based on permanent magnet arrangement according to claim 6, wherein the first shell is provided with a first end face flange, the second shell is provided with a second end face flange matched with the first end face flange, and the first end face flange and the second end face flange are fixedly connected through a bolt-nut pair; the second shell is provided with a third end face flange, and the third end face flange is fixedly connected with the end cover plate through a bolt and nut pair.

8. The passive compliance device of six degrees of freedom mechanical arm tip based on permanent magnet arrangement of claim 6, wherein the end of the second housing facing the first housing is provided with a collar extending into and mating with the port of the first housing.

9. The six degree of freedom mechanical arm end passive compliance device based on permanent magnet arrangement of claim 8, wherein when the end cover plate is covered on the second housing, the end cover plate presses the plurality of sets of radial permanent magnet assemblies against the convex ring.

10. The six-degree-of-freedom mechanical arm tail end passive softening device based on permanent magnet arrangement according to claim 1, wherein a first positioning sleeve is sleeved on the movable shaft, one end of the first positioning sleeve is propped against the second axial permanent magnet assembly, and the other end of the first positioning sleeve is propped against the inner ring magnetic pole group close to one side of the first shell; the movable shaft is sleeved with a second positioning sleeve, one end of the second positioning sleeve is propped against the inner ring magnetic pole group far away from one side of the first shell, and the other end of the second positioning sleeve is propped against the shaft shoulder of the movable shaft.