CN116829311A

CN116829311A - Six-degree-of-freedom motion mechanism

Info

Publication number: CN116829311A
Application number: CN202180091215.7A
Authority: CN
Inventors: 周啸波
Original assignee: Suzhou Mailan Technology Co ltd
Current assignee: Suzhou Mailan Technology Co ltd
Priority date: 2021-03-25
Filing date: 2021-03-25
Publication date: 2023-09-29
Also published as: WO2022198587A1

Abstract

A six-degree-of-freedom motion mechanism convenient to drive comprises a platform (10) and three branched chains (20), wherein each branched chain (20) comprises a base (20 a), a first-stage movable part (21), a second-stage movable part (22) and a third-stage movable part (23), the first-stage movable part (21) comprises a first-stage movable part (211) and a second-stage movable part (212), the second-stage movable part (22) comprises a second-stage first guide part (221) and a second-stage second guide part (222) which are fixed in positions relative to each other, the second-stage first guide part (221) provides a guide for the second-stage movable part (22) to reciprocate along a first guide direction (D1), and the second-stage second guide part (222) provides a guide for the second-stage movable part (22) to reciprocate along a second guide direction (D2), and the platform (10) has three degrees of freedom and three degrees of freedom of rotation relative to the base (20 a).

Description

Six-degree-of-freedom motion mechanism

Technical Field

The application relates to the field of motion mechanisms, in particular to a motion mechanism with six degrees of freedom, which is convenient to drive.

Background

In some movement mechanisms for realizing complex operations, the movement mechanism is required to have more degrees of freedom, larger stroke, rigidity, speed, higher precision and the like, and the requirements in these aspects are generally not easy to be met.

Disclosure of Invention

The application aims to overcome or at least alleviate the defects in the prior art and provide a six-degree-of-freedom movement mechanism which is convenient to drive.

Provides a six-degree-of-freedom motion mechanism which is convenient to drive, comprising a platform and three branched chains, wherein,

each branched chain comprises a base station, a first-stage movable piece, a second-stage movable piece and a third-stage movable piece,

the first-stage movable piece comprises a first-stage first movable piece and a second-stage movable piece,

the first-stage first movable piece is connected with the base station and the second-stage movable piece, can translate in a first direction relative to the base station,

the primary second movable piece is connected with the base station and the secondary movable piece, the primary second movable piece can translate in a first direction relative to the base station,

the secondary moving member includes a secondary first guide member and a secondary second guide member fixed in position with respect to each other, the secondary first guide member providing a guide for the secondary moving member to reciprocate in a first guide direction relative to the primary first moving member, the secondary second guide member providing a guide for the secondary moving member to reciprocate in a second guide direction relative to the primary second moving member,

the secondary movable piece can displace relative to the base in the first direction and the second direction;

the first and second guide directions are not parallel to each other and to the first direction,

the third-stage moving part can displace in a third direction relative to the second-stage moving part, at least one of the first-stage moving part, the second-stage moving part and the third-stage moving part is a driving part,

the three-stage moving part is connected with the platform through a rotary connecting structure, the rotary connecting structure enables the platform to have three degrees of freedom of rotation around the first direction, the second direction and the third direction relative to the three-stage moving part,

the platform has three translational degrees of freedom and three rotational degrees of freedom relative to the base.

In at least one embodiment, the first directions of at least two of the branches are parallel.

In at least one embodiment, none of the first directions of the three branches are parallel.

In at least one embodiment, the abutment provides a first guide for translation of the primary moving members, at least two of the primary moving members sharing one of the first guides.

In at least one embodiment, the first direction is a circular arc direction.

In at least one embodiment, in each of the branches, at least one of the primary first movable member and the primary second movable member includes first and second sub-members relatively rotatable about an axis parallel to the third direction, at most one pair of the first and second sub-members being followers.

In at least one embodiment, the tertiary mover is translatable relative to the secondary mover.

In at least one embodiment, the first direction and the second direction are both parallel to a first plane, and the third direction is perpendicular to the first plane.

In at least one embodiment, the secondary moving member includes a ramp surface disposed obliquely relative to the first plane, the tertiary moving member being reciprocally movable along the ramp surface, or

The tertiary movable member is movable in a vertical direction with respect to the secondary movable member.

In at least one embodiment, the tertiary movable member is rotatable relative to the secondary movable member about an axis perpendicular to the third direction.

In at least one embodiment, the rotational coupling structure includes a first portion and a second portion that are rotatable relative to one another, one of the first portion and the second portion being coupled to the platform and the other being coupled to the tertiary mover,

the first portion comprising a first bulb, the second portion comprising a plurality of second bulbs,

the plurality of second spherical bosses surround and contact the first spherical boss, and the contact surfaces of the first spherical boss and the second spherical boss are spherical surfaces.

In at least one embodiment, one of the first domes is in contact with three of the second domes.

In at least one embodiment, the first portion and the second portion have a force of attraction to each other by means of a magnetic field.

In at least one embodiment, the second portion includes a magnet, the first dome-shaped material includes a ferromagnetic material, and the magnet is not in contact with the first portion.

In at least one embodiment, for each of the branches, the primary first and secondary second movable members of the primary movable member are driving members and the secondary and tertiary movable members are driven members. The driving part can be a motor lead screw guide rail module, a linear motor guide rail module, a piezoelectric ceramic motor guide rail module or other driving devices, and the position feedback is correspondingly provided by a sensor such as an encoder or a grating ruler. The follower may also optionally be provided with sensors such as a grating ruler to provide positional feedback for enhanced accuracy positional compensation, calibration, etc.

The six-degree-of-freedom motion mechanism is simple in structure and convenient to control.

Drawings

Fig. 1 is a schematic view of a six degree of freedom motion mechanism according to a first embodiment of the present application.

Fig. 2 and 3 are schematic views of a differential motion of a branched chain of a six-degree-of-freedom motion mechanism according to a first embodiment of the present application.

Fig. 4 is a schematic view of a rotational coupling structure of a six-degree-of-freedom moving mechanism according to a first embodiment of the present application, taken along a third direction.

Fig. 5 is a schematic view of the first and second domes of the rotary joint structure of fig. 4 in cross section through three points of contact.

Fig. 6 to 8 are schematic views of three variations of a six degree-of-freedom movement mechanism according to a second embodiment of the present application.

Fig. 9 is a schematic view of a six degree of freedom motion mechanism according to a third embodiment of the present application.

Fig. 10 is a schematic view of a six degree of freedom motion mechanism according to a fourth embodiment of the present application.

Reference numerals illustrate:

10 platforms; 20 branches; 20a base station; 21-stage moving parts; 211 first stage first movable member; 212a first stage second movable member; 211g of first-stage first guide member; 212g primary second guide; 211a first movable member first sub-assembly; 211b a first movable member second sub-member; 212a second movable member first sub-member; 212b a second movable member second sub-component;

22 second-stage moving parts; 221 second stage first guide; 222 secondary second guide; a 22s slope surface; 23 three-stage moving parts;

j, rotating the connecting structure; a first part of J1; j10 first bulb; a second moiety J2; j20 second bulb; a J21 magnet;

x a first direction; y a second direction; and z the third direction.

Detailed Description

Exemplary embodiments of the present application are described below with reference to the accompanying drawings. It should be understood that these specific illustrations are for the purpose of illustrating how one skilled in the art may practice the application, and are not intended to be exhaustive of all of the possible ways of practicing the application, nor to limit the scope of the application.

The present application describes the positional relationship of the respective members in a three-dimensional coordinate system shown in fig. 1 unless otherwise specified. It should be understood that the positional relationship defined according to the x, y and z axes in the present application is relative, and the coordinate axes may be spatially rotated according to the actual application of the device.

(first embodiment)

Referring to fig. 1 to 3, a six-degree-of-freedom movement mechanism (hereinafter referred to as a mechanism) according to a first embodiment of the present application will be described.

The mechanism includes a platform 10 and three branches 20 that support and control the movement of the platform 10. The platform 10 and the branches 20 are connected by a rotational connection J that provides each branch 20 with rotational freedom in three directions (about the x-axis, about the y-axis, and about the z-axis) relative to the platform. Six degrees of freedom motion of platform 10 may be achieved by driving three branches 20 cooperatively (e.g., by computationally determining the position of the driving member of each branch 20).

Each branched chain 20 includes a base 20a, a primary movable member 21, a secondary movable member 22, and a tertiary movable member 23, which are connected in sequence. Alternatively, each of the branched chains 20 may have a separate base 20a, or a plurality of branched chains 20 may share a single base 20a.

The primary mover 21 is superposed on the base 20a, the secondary mover 22 is superposed on the primary mover 21, and the tertiary mover 23 is superposed on the secondary mover 22.

The primary mover 21 is capable of reciprocating (translating) in the first direction x with respect to the base 20 a; the secondary moving member 22 is displaceable in the second direction y with respect to the primary moving member 21; the tertiary movable member 23 is capable of reciprocating (translating) relative to the secondary movable member 22 along a ramp surface 22s, which ramp surface 22s forms a drop in the third direction z, whereby the tertiary movable member 23 is capable of displacing relative to the secondary movable member 22 in the third direction z and the first direction x. It should be understood that the translation herein is relative to rotation, although in the present embodiment the translation is in a linear direction, this is not required, i.e. the translation may also be a curvilinear translation.

The primary mover 21 includes a primary first mover 211 and a primary second mover 212 that can be independently controlled. The base 20a provides a first guide (not shown, such as a rail or a guide groove) for movement of the primary first movable member 211 and the primary second movable member 212 in the x-direction. Alternatively, the first stage moving member 211 and the second stage moving member 212 belonging to the same branch 20 share the same or the same set of first guides.

The primary first movable member 211 includes a primary first guide 211g, and the primary second movable member 212 includes a primary second guide 212g.

The secondary mover 22 includes a secondary first guide 221 and a secondary second guide 222. The positions and postures of the secondary first guide 221 and the secondary second guide 222 are relatively fixed. More specifically, the secondary first guide 221 and the secondary second guide 222 may be provided, in particular, fixedly provided, to the base body of the secondary mover 22, for example, a plate-shaped base body.

Referring to fig. 2 and 3 together, the primary first guide 211g is engaged with the secondary first guide 221, and the primary second guide 212g is engaged with the secondary second guide 222. The primary and secondary first guides 211g and 221 can reciprocate only in the first guide direction D1, and the primary and secondary second guides 212g and 222 can reciprocate only in the second guide direction D2.

The first guiding direction D1 and the second guiding direction D2 are not parallel to the first direction x.

Thus, in the case where either one of the primary first mover 211 and the primary second mover 212 is displaced in the first direction x with respect to the base 20a, the secondary mover 22 can be displaced in the second direction y with respect to the base 20a. Further, in the case of reasonably controlling the displacement of the primary first movable member 211 and the primary second movable member 212, the secondary movable member 22 can be simultaneously displaced in the first direction x with respect to the base 20a.

By this differential manner, only the displacement of the primary first movable member 211 and the primary second movable member 212 in the first direction x with respect to the base 20a can be controlled, and control of the displacement of the secondary movable member 22 in the first direction x and the second direction y can be achieved.

Referring to fig. 2, fig. 3 shows a case where the displacement of the secondary mover 22 in the first direction x and the second direction y with respect to the base 20a is achieved by moving the primary first mover 211 and the primary second mover 212 in the first direction x. For example, alternatively, the first guiding direction D1 and the second guiding direction D2 form an included angle of 90 degrees and each form an angle of 45 degrees with the first direction x, so that the differential displacement amount of the first stage first movable member 211 and the second stage second movable member 212 in the first direction x is exactly equal to the displacement of the second stage movable member 22 in the second direction y. In other possible embodiments, the first guiding direction D1 may be parallel to the second direction y, and the second guiding direction D2 may form an acute angle with the first direction x (hereinafter, this angle will be simply referred to as an angle theta), where the first stage first movable member 211 may be a reference of the second stage movable member 22 in the first direction x, and the displacement of the second stage movable member 22 in the second direction y may be determined by the displacement of the first stage second movable member 212 relative to the first stage first movable member 211 in the first direction x and the angle theta. Of course, the first guiding direction D1 and the second guiding direction D2 may take other angle values with respect to the first direction x to adapt to different applications.

In the present embodiment, the first-stage first guide 211g is a guide rail, and the second-stage first guide 221 is a slider. It should be appreciated that in other possible embodiments, the primary first guide 211g may be provided as a slider, and the secondary first guide 221 may be provided as a rail, a guideway, or a guide bar. Similarly, one of the primary second guide 212g and the secondary second guide 222 may be a guide rail, a guide groove, or a guide bar, and the other may be a slider-like structure. Or both may be rails, such as pairs of cross roller rails. Further, it should be understood that while the secondary first guide 221 and the secondary second guide 222 in fig. 2 and 3 are each smaller in size in the first guide direction D1 and the second guide direction D2, the primary first guide 211g and the primary second guide 212g are each larger in size in the first guide direction D1 and the second guide direction D2, respectively, this is not required. For example, in the first guide direction D1, the size of the secondary first guide 221 may also be equal to or larger than the size of the primary first guide 211 g.

The surface of the secondary moving member 22 contacting the tertiary moving member 23 is a slope surface 22s, and the secondary moving member 22 provides the tertiary moving member 23 with a third guide member that moves in the inclined elevating direction of the slope surface 22s, so that the tertiary moving member 23 can be displaced in the third direction z and the first direction x and/or the second direction y with respect to the base 20a.

One of the primary movable member 21, the secondary movable member 22 and the tertiary movable member 23 is a driving member, and the other two are driven members.

For example, the primary movable member 21 (the primary first movable member 211 and the primary second movable member 212) is a driving member, and the secondary movable member 22 and the tertiary movable member 23 are driven members. By driving the primary first movable member 211 and the primary second movable member 212 in the first direction x, respectively, the secondary movable member 22 is displaced in the first direction x and the second direction y with respect to the primary movable member 21, and the tertiary movable member 23 is displaced in the third direction z and the second direction y with respect to the secondary movable member 22. Three translational degrees of freedom of the tertiary movement 23 of each branch 20 in the first direction x, in the second direction y and in the third direction z are thereby achieved.

Alternatively, the secondary moving member 22 or the tertiary moving member 23 may be configured as an active member. The driving part can be a motor lead screw guide rail module, a linear motor guide rail module, a piezoelectric ceramic motor guide rail module or other driving devices, and the position feedback is correspondingly provided by a coder, a grating ruler or other sensors. The follower may also optionally be provided with sensors such as a grating ruler to provide positional feedback for improved control accuracy, calibration, etc. Preferably, when the primary moving member 21 is used as the active member, for example, a linear motor module is used, the primary first moving member 211 and the primary second moving member 212 are respectively provided with a rotor and a grating reading head, and the primary first moving member 211 and the primary second moving member 212 share the same group of stators and grating tape which are installed on the base 20a, so that the structure is more compact, the precision is higher, and the cost is lower.

The description of the movable parts in each of the branches 20 uses the coordinate system of the branch 20 itself, and in this embodiment, the coordinate systems of the branches 20 are different, specifically, the first direction x and the second direction y of the branches 20 are different (or are not parallel, and the direction same/direction parallel referred to in the present application includes parallel but not collinear, and collinear cases). In the present embodiment, it is preferable that the three branches 20 are arranged at equal intervals.

Because the three-stage moving member 23 and the platform 10 use the rotational connection structure J capable of universal rotation, as the three branched chains 20 are driven respectively, the positions of the three-stage moving members 23 change, and the platform 10 has three translational degrees of freedom, and also three rotational degrees of freedom about the first direction x, about the second direction y, and about the third direction z. Thus, the platform 10 has six degrees of freedom.

Referring next to fig. 4 and 5, a rotary joint structure J according to the present application will be described.

The rotational coupling structure J includes a first portion J1 and a second portion J2. The first portion J1 is fixedly connected to the platform 10 (or the first portion J1 is a part of the platform 10), and the second portion J2 is fixedly connected to the tertiary mover 23 (or the second portion J2 is a part of the tertiary mover 23).

The first portion J1 comprises a first bulb J10. The second portion J2 includes three second bulb J20. And preferably, the first dome J10 is fixedly connected with the body J1m of the first portion J1, or the first dome J10 and the body J1m are formed as a whole; the second dome J20 is fixedly connected to the body J2m of the second portion J2, or the second dome J20 and the body J2m are integrally formed.

Three second domes J20 are disposed around the first dome J10, and the second domes J20 are in contact with the first dome J10.

The surfaces of the first and second domes J10 and J20 contacting each other are spherical, whereby the first dome J10 circumscribes each of the second domes J20 to form a point contact. Three second domes J20 form three points of contact with one first dome J10, thereby uniquely determining the position of the first dome J10.

Compared with a rotary connecting structure formed by matching a ball and a ball socket in the prior art, the connecting mode of the first part J1 and the second part J2 has higher transmission precision.

Since the first dome J10 forms a point contact with the second dome J20 and the first portion J1 is placed directly above the second portion J2, the first and second portions J1, J2 are preferably arranged to be attracted to each other by means of a magnetic field in order to avoid that the first portion J1 breaks away from the second portion J2 during movement, e.g. due to inertia.

For example, the second portion J2 further includes a magnet J21, and the material of which the first dome J10 is made includes a ferromagnetic material. The magnet J21 and the first spherical protrusion J10 are not contacted, the first part J1 is kept in a state of being contacted with the second part J2 only by the constraint force of a magnetic field, and the friction force between the magnet J21 and the first spherical protrusion J10 is small, so that the positioning is accurate.

It should be appreciated that, where other possibilities are possible, the mutually attracting portions of the first and second portions J1 and J2 (e.g., the magnetically active portion of the second portion J2 and the first bulb J10) may also be in contact to increase the magnetic field attraction force.

It should be appreciated that the first portion J1 rests above the second portion J2 by gravity alone, except for the restraining force of the magnetic field.

Alternatively, in order to further improve the accuracy of control of the movement position of the platform 10, position sensors may be provided for the followers in the primary movable member 21, the secondary movable member 22, and the tertiary movable member 23. For example, in the case where the secondary movable member 22 and the tertiary movable member 23 are followers, grating scales may be provided near the secondary movable member 22 and the tertiary movable member 23, respectively, to measure the real-time positions of the secondary movable member 22 and the tertiary movable member 23. Based on the real-time position of the driven member, a feedback regulation mechanism is established, and the motion of the driving member is timely regulated so as to improve the precision of the final synthesized motion; redundant position sensor information also facilitates calibration of the platform.

Alternatively, a position sensor can also be provided for the active element. Alternatively, it is also possible to provide position sensors only for three-stage moving members 23 (connected to the platform 10) located at the terminal.

Alternatively, in other possible implementations, the secondary movable member 22 may also provide the tertiary movable member 23 with a third guide member parallel to the third direction z, i.e. to translate the tertiary movable member 23 in the third direction z. In this case, the tertiary movable member 23 preferably serves as a driving member.

In summary, six degrees of freedom control of the platform 10 can be achieved by independently driving the three branches 20.

(second embodiment)

A second embodiment according to the present application is explained below with reference to fig. 6 to 8. The second embodiment is a modification of the first embodiment, the same reference numerals are given to the same or similar components as those in the first embodiment in terms of structure or function, and detailed description of these components is omitted.

In the present embodiment, the first direction x and the second direction y of each of the three branches 20 are the same. Further, the present embodiment includes three modifications.

Referring to fig. 6, in the first modification, three first guides that guide the three primary moving members 21 are parallel to each other, and each primary moving member 21 can reciprocate along one first guide (i.e., in the same first direction x). The three primary moving members 21 reciprocate in the same first direction x. The positions of the two branches 20 and the other branch 20 are staggered in the first direction x. The positions of the three branches 20 are staggered in the second direction y. The positions of the three branches 20 are the same in the third direction z.

Referring to fig. 7, in the second modification, two branches 20 share one first guide, and the other branch 20 uses the other first guide. I.e. the mechanism has only two first guides. Both first guides extend along the same first direction x and are staggered in the second direction y. Alternatively, one first guide shared by two branches 20 may also be represented by two separate first guides spaced apart or spaced apart in the first direction x.

Referring to fig. 8, in a third variation, three branches 20 share a first guide. I.e. the mechanism has only one first guide.

The first guide according to the present embodiment may have a greater length in the first direction x, thereby allowing the platform 10 to have a greater movable space in the first direction x.

The mechanism for sharing a first guide for the plurality of branches 20 is more compact, adaptable to operational needs and occupies less space.

As shown in fig. 6 and 7, the extending directions of the slope surfaces 22s may not be parallel.

(third embodiment)

A third embodiment according to the present application is described below with reference to fig. 9. The third embodiment is a modification of the first embodiment, the same reference numerals are given to the same or similar components as those in the first embodiment in terms of structure or function, and detailed description of these components is omitted.

In the present embodiment, the first direction x is a circular arc direction, and the first movable members 21 of the three branches 20 share one annular (preferably circular) first guide member.

In this arrangement, the platform 10 can rotate around an axis parallel to the third direction z with an unlimited angle, and is particularly suitable for a situation where the platform 10 needs to perform more rotation operations.

Referring to fig. 9, the second direction y is perpendicular to the first direction x. The first direction x may be a circular arc direction (circumferential direction), and the second direction y is a direction along a radial direction of the circular arc. The three branches 20 may be equally spaced in the circumferential direction (first direction x), i.e., 120 degrees apart.

In the present embodiment, at least one of the primary first movable member 211 and the primary second movable member 212 includes two relatively rotatable portions. Taking the primary first movable member 211 as an example, the primary first movable member 211 includes a first movable member first sub-member 211a and a first movable member second sub-member 211b, and the first movable member first sub-member 211a and the first movable member second sub-member 211b are rotatable relative to each other about an axis parallel to the third direction z, the rotation being a follow-up during movement of the primary first movable member 211 along the circular arc-shaped first guide member.

In the above arrangement, the primary second movable member 212 may be integral or may include a second movable member first sub-member 212a and a second movable member second sub-member 212b that are rotation-controlled. That is, the rotation of the second moveable member first sub-component 212a and the second moveable member second sub-component 212b relative to each other is not follow-up, but rather controlled.

Alternatively, both the two sub-parts of the primary first movable member 211 (the first movable member first sub-part 211a and the first movable member second sub-part 211 b) and both the two sub-parts of the primary second movable member 212 (the second movable member first sub-part 212a and the second movable member second sub-part 212 b) may be controlled to rotate.

(fourth embodiment)

A fourth embodiment according to the present application will be described below with reference to fig. 10. The fourth embodiment is a modification of the second embodiment, the same reference numerals are given to the same or similar components as those in the second embodiment in terms of structure or function, and detailed description of these components is omitted.

In the present embodiment, the tertiary moving member 23 is configured to be relatively rotatably connected with the secondary moving member 22. During the rotation of the tertiary movable member 23 relative to the secondary movable member 22, the tertiary movable member 23 is displaced in the third direction z relative to the secondary movable member 22.

The axis of rotation of the tertiary movable member 23 relative to the secondary movable member 22 is perpendicular to the third direction z (or parallel to the first plane). The direction of rotation of the tertiary movement 23 is indicated by arrow ω.

It should be appreciated that the axis of rotation of the tertiary mover 23 does not have to be parallel to the first direction x. The branches 20 are also not necessarily symmetrical.

The tertiary movement 23 can be used as a driving part or a driven part.

In the present embodiment, the position sensor provided for the three-stage moving member 23 as the rotating member may be, for example, a rotary encoder.

It should be appreciated that in order to avoid the tertiary mover 23 rotating to an undesired angle during rotation, a limit stop may be provided for the tertiary mover 23.

It will be appreciated that the above embodiments and portions of aspects or features thereof may be suitably combined.

Some advantageous effects of the above-described embodiments of the present application are briefly described below.

(i) The mechanism has a simple structure, can realize the control of six degrees of freedom of the platform 10 by independently driving any stage of movable part in each branched chain 20, and has a simple driving mode and convenient operation.

(ii) The transmission precision of the rotary connecting structure J is high, and the connecting strength of the first part J1 and the second part J2 can be enhanced by utilizing a magnetic field.

It should be understood that the above-described embodiments are merely exemplary and are not intended to limit the present application. Those skilled in the art can make various modifications and changes to the above-described embodiments without departing from the scope of the present application. For example, the number of the cells to be processed,

(i) The rotational coupling structure J may also be configured such that the second portion J2 is fixedly coupled to the platform 10 (or the second portion J2 is a part of the platform 10), and the first portion J1 is fixedly coupled to the tertiary movable member 23 (or the first portion J1 is a part of the tertiary movable member 23).

(ii) The magnet J21 may be a permanent magnet or an electromagnet.

(iii) The second portion J2 may also have more than three second domes J20, which may be more suitable for use in situations where the platform 10 is required to carry a relatively large load.

(iv) The first dome J10 may be rotatably connected to the body J1m of the first portion J1, and the second dome J20 may be rotatably connected to the body J2m of the second portion J2.

(v) The rotational connection J of the three branches may be asymmetric, for example, the angle formed by each first portion J1 with the platform 10 may be different.

(vi) The platform 10 may be a component for mounting a terminal operating mechanism (e.g., a manipulator or surgical instrument), or may be part of, or integral with, the terminal operating mechanism.

(vii) Although only one of the primary movable element 21, the secondary movable element 22 and the tertiary movable element 23 is required to be a driving element and the other two are required to be driven elements for each branched chain 20, the number of driving elements may be increased to provide redundant control in consideration of various aspects such as improving control accuracy.

Claims

A six-degree-of-freedom motion mechanism convenient to drive comprises a platform (10) and three branched chains (20), wherein,

each branched chain (20) comprises a base (20 a), a first-stage movable part (21), a second-stage movable part (22) and a third-stage movable part (23),

the primary movable piece (21) comprises a primary first movable piece (211) and a primary second movable piece (212),

the primary first movable piece (211) is connected with the base station (20 a) and the secondary movable piece (22), the primary first movable piece (211) can translate in a first direction (x) relative to the base station (20 a),

the primary second movable piece (212) is connected with the base station (20 a) and the secondary movable piece (22), the primary second movable piece (212) can translate in a first direction (x) relative to the base station (20 a),

the secondary moving member (22) comprises a secondary first guide member (221) and a secondary second guide member (222) which are fixed in position with respect to each other, the secondary first guide member (221) provides a guide for the secondary moving member (22) to reciprocate in a first guide direction (D1) relative to the primary first moving member (211), the secondary second guide member (222) provides a guide for the secondary moving member (22) to reciprocate in a second guide direction (D2) relative to the primary second moving member (212),

the secondary moving member (22) is displaceable in the first direction (x) and the second direction (y) with respect to the base (20 a);

the first guiding direction (D1) and the second guiding direction (D2) are not parallel to each other and to the first direction (x),

the three-stage moving part (23) can displace in a third direction (z) relative to the two-stage moving part (22), at least one of the first-stage moving part (21), the two-stage moving part (22) and the three-stage moving part (23) is a driving part,

the three-stage moving part (23) is connected with the platform (10) through a rotary connecting structure (J), the rotary connecting structure (J) enables the platform (10) to have three rotary degrees of freedom around the first direction (x), the second direction (y) and the third direction (z) relative to the three-stage moving part (23),

the platform (10) has three translational degrees of freedom and three rotational degrees of freedom relative to the base (20 a).
Six degree of freedom movement mechanism according to claim 1, characterized in that the first directions (x) of at least two of the branches (20) are parallel.
Six degree of freedom movement mechanism according to claim 1, characterized in that none of the first directions (x) of the three branches (20) are parallel.
Six degree of freedom movement mechanism according to claim 2, characterized in that the base (20 a) provides a first guide for the translation of the primary moving members (21), at least two of the primary moving members (21) sharing one of the first guides.
Six degree-of-freedom movement mechanism according to claim 4, characterized in that the first direction (x) is a circular arc direction.
The six degree-of-freedom motion mechanism of claim 5 wherein in each of the branches (20), at least one of the primary first movable member (211) and the primary second movable member (212) includes first and second sub-members relatively rotatable about an axis parallel to the third direction (z), at most one pair of the first and second sub-members being followers.
Six degree of freedom movement mechanism according to claim 1, characterized in that the tertiary movement (23) is translatable with respect to the secondary movement (22).
The six degree of freedom motion mechanism of claim 7 wherein the first direction (x) and the second direction (y) are both parallel to a first plane and the third direction (z) is perpendicular to the first plane.
The six-degree-of-freedom movement mechanism according to claim 8, wherein the secondary moving member (22) includes a slope surface (22 s), the slope surface (22 s) being provided obliquely with respect to the first plane, the tertiary moving member (23) being reciprocable along the slope surface (22 s), or

The tertiary movable member (23) is movable in a vertical direction with respect to the secondary movable member (22).
Six degree-of-freedom movement mechanism according to claim 1, characterized in that the tertiary movement (23) is rotatable with respect to the secondary movement (22) about an axis perpendicular to the third direction (z).
Six degree-of-freedom movement mechanism according to claim 1, characterized in that the rotational connection (J) comprises a first part (J1) and a second part (J2) which are rotatable relative to each other, one of the first part (J1) and the second part (J2) being connected to the platform (10) and the other being connected to the tertiary movement (23),

said first portion (J1) comprising a first bulb (J10), said second portion (J2) comprising a plurality of second bulbs (J20),

the plurality of second domes (J20) encircle and contact the first domes (J10), and the contact surfaces of the first domes (J10) and the second domes (J20) are spherical surfaces.
The six degree of freedom motion mechanism of claim 11 wherein one of the first lobes (J10) is in contact with three of the second lobes (J20).
Six degree of freedom movement mechanism according to claim 11, characterized in that the first portion (J1) and the second portion (J2) have a force of mutual attraction by means of a magnetic field.
The six degree of freedom motion mechanism of claim 13 wherein the second portion (J2) includes a magnet (J21), the first bulb (J10) is made of a material including a ferromagnetic material, and the magnet (J21) is not in contact with the first portion (J1).
Six degree of freedom movement mechanism according to any one of claims 1 to 14, characterized in that for each of the branches (20), the primary first (211) and primary second (212) movable members of the primary movable member (21) are driving members, and the secondary (22) and tertiary movable members (23) are driven members.