WO2021179210A1

WO2021179210A1 - Multi-degree-of-freedom parallel mechanism and parallel mechanism assembly

Info

Publication number: WO2021179210A1
Application number: PCT/CN2020/078824
Authority: WO
Inventors: 周啸波
Original assignee: 苏州迈澜医疗科技有限公司
Priority date: 2020-03-11
Filing date: 2020-03-11
Publication date: 2021-09-16
Also published as: CN115175790A

Abstract

A multi-degree-of-freedom parallel mechanism and an assembly provided with the parallel mechanism. The parallel mechanism comprises a guide piece (G), two primary branches (1) and one secondary branch (2); each primary branch (1) comprises two active pieces (11), one branch platform (12) and a plurality of primary connecting rods, the active pieces (11) being capable of moving back and forth along the guide piece (G); the secondary branch (2) comprises one positioning platform (20) and a plurality of secondary connecting rods; one of the two active pieces (11) in each primary branch (1) is connected to the branch platform (12) via at least two primary connecting rods to form a parallelogram which is parallel with a first plane (xoz); one of the two branch platforms (12) is connected to the positioning platform (20) in the secondary branch (2) via at least two secondary connecting rods to form a parallelogram which is capable of moving within a second plane (xoy); the first plane (xoz) is perpendicular to the second plane (xoy). The multi-degree-of-freedom parallel mechanism is compact and simple in structure and easy to control, and has a large range of movement on the vertical direction.

Description

Multi-degree-of-freedom parallel mechanism and parallel mechanism assembly

Technical field

The invention relates to the field of robots, in particular to a multi-degree-of-freedom parallel mechanism and a parallel mechanism assembly of a parallel robot.

Background technique

From the perspective of mechanism, robots can be divided into two categories: series robots and parallel robots. Compared with series robots, parallel robots have the advantages of greater rigidity, strong carrying capacity, high precision, and low end piece inertia.

Most of the existing parallel robots adopt a completely symmetrical design, which results in a larger overall size of the robot, which cannot be well adapted to a small operating space, or multiple robots cannot be arranged in a limited space at the same time.

The most common parallel robots are mostly six degrees of freedom. For example, the patent publication US3295224A discloses a parallel robot for motion simulation. However, the cost of a parallel robot with full six degrees of freedom is often that the motion space of each degree of freedom is roughly equally divided, and the demand for greater motion space in certain directions cannot be well satisfied. Therefore, people limit the degree of freedom in certain directions according to specific needs, in exchange for greater movement space in other directions. The most widely used in this regard is the parallel robot used for picking operations, most of which provide three degrees of freedom for translation and one rotation. For example, Patent Publication WO2009053506A1 discloses a four-degree-of-freedom parallel robot. Its support part uses multiple non-coplanar four-bar linkage mechanisms. The motions of these non-coplanar four-bar linkage mechanisms restrict each other, making the terminal motion The platform cannot realize two degrees of freedom of translation and rotation. However, in applications such as surgical robots or machine tools, it is necessary to control the degree of freedom of at least two translations and two rotations of the tool, and the above-mentioned parallel mechanism that provides three translations and one rotation is not applicable.

Chinese patent CN105729450B discloses a four-degree-of-freedom parallel mechanism, which can realize the freedom of three translational movement and one rotation of the movable platform, but cannot realize the rotation of the movable platform around the y direction or around the x direction. In addition, the scheme also has the following shortcomings:

(i) The movement of the moving platform in the x direction and the z direction is coupled. Due to the influence of the movement in the x direction, the range of movement in the z direction is limited;

(ii) The guide rails used to guide the movement of the slider are two spaced apart guide rails, which makes the whole mechanism occupy a large space, which is not conducive to the arrangement in a limited space.

Summary of the invention

The purpose of the present invention is to overcome or at least alleviate the above-mentioned shortcomings of the prior art, and to provide a multi-degree-of-freedom parallel mechanism and a parallel mechanism assembly.

According to the first aspect of the present invention, a multi-degree-of-freedom parallel mechanism is provided, which includes a guide, two primary branches and one secondary branch, wherein,

Each of the primary side chains includes two driving members, a side chain platform, and a plurality of primary links connecting the driving member and the side chain platform, and the driving member can reciprocate along the guide , The secondary side chain includes a positioning platform and a plurality of secondary links connecting the side chain platform and the positioning platform,

In each of the first-level branch chains, one of the two active parts is connected to the branch chain platform by at least two first-level links, wherein the two ends of the first-level first rod are respectively It is rotatably connected to the first point and the second point of the first level with the active part and the branch chain platform, and both ends of the first level second rod are rotatably connected to the active part and the branch chain platform. The third point of the first level and the fourth point of the first level, the quadrilateral obtained by sequentially connecting the first point of the first level, the second point of the first level, the fourth point of the first level and the third point of the first level is and Parallelogram with the first plane parallel; the other of the two active parts is connected to the branch chain platform or the first-level first rod through at least one of the first-level connecting rods to determine the The posture of the parallelogram defined by the first-level first rod and the first-level second rod,

In the secondary side chain, one of the two side chain platforms is connected to the positioning platform by at least two secondary links, and both ends of the secondary first rod are connected to the positioning platform respectively. The branch chain platform and the positioning platform are rotatably connected to the secondary first point and the secondary second point, and both ends of the secondary second rod are respectively rotatably connected to the secondary chain platform and the positioning platform. The third point and the second-level fourth point, the quadrilateral obtained by sequentially connecting the second-level first point, the second-level second point, the second-level fourth point, and the second-level third point can be A parallelogram that moves in the second plane; the other of the two branch chain platforms is connected to the positioning platform or the second-stage first rod through at least one of the two-stage connecting rods to rotate Determining the posture of the parallelogram defined by the second-level first rod and the second-level second rod,

The first plane is not parallel to the second plane, and the guide is parallel to the second plane,

The positioning platform has at least three translational degrees of freedom.

In at least one embodiment, the first plane is perpendicular to the second plane.

In at least one embodiment, in each of the first-level branch chains, the other one of the two active parts is connected to the first-level first rod through the first-level third rod, and the one The two ends of the third-level rod are respectively connected to the first-level fifth point and the sixth-level point in rotation with the active member and the first-level first rod. The sixth-level point is connected to the first-level first rod The points do not overlap,

The other of the two branch chain platforms is connected to the second-level first rod through a second-level third rod, and both ends of the second-level third rod are connected to the branch chain platform and the The second-level first rod is rotatably connected to the second-level fifth point and the second-level sixth point, and the second-level sixth point does not coincide with the second-level first point.

In at least one embodiment, the sixth point of the first level coincides with the second point of the first level, and/or

The second-level sixth point coincides with the second-level second point.

In at least one embodiment, in each of the first-level branch chains, the other one of the two active elements is also connected to the first-level second rod through the first-level fourth rod, and the The two ends of the first-level fourth rod are respectively connected to the first-level seventh point and the first-level eighth point with the active member and the first-level second rod respectively, and sequentially connect the first-level fifth point and the first-level fifth point and the first-level second rod. The quadrilaterals obtained by the sixth point at the first level, the eighth point at the first level, and the seventh point at the first level are parallelograms, and/or

The other one of the two branch chain platforms is also connected to the second-level second rod through a second-level fourth rod, and both ends of the second-level fourth rod are connected to the branch chain platform and The second-level second rod is rotatably connected to the second-level seventh point and the second-level eighth point, and sequentially connects the second-level fifth point, the second-level sixth point, the second-level eighth point and the second-level eighth point. The quadrilateral obtained by the seventh point of the second level is a parallelogram.

In at least one embodiment, the four active elements share one guide element.

In at least one embodiment, the branch chain platform includes a base table and a turntable, and the turntable can rotate relative to the base table around a branch chain axis of rotation,

The primary link is connected to the abutment, and the secondary link is connected to the turntable.

In at least one embodiment, the branched chain shaft is parallel to the second plane.

In at least one embodiment, the positioning platform includes a terminal positioning platform and two rotational positioning platforms, the rotational positioning platform is rotationally connected to the terminal positioning platform, and the secondary link is rotationally connected to the positioning platform The point is located on the rotating positioning platform, each of the rotating positioning platforms can rotate relative to the terminal positioning platform about the rotation axis of the positioning platform, and the terminal positioning platform has at least three translational degrees of freedom and one rotational degree of freedom.

In at least one embodiment, the rotation axis of the positioning platform is perpendicular to the second plane.

In at least one embodiment, the first plane is a vertical plane, and the second plane is a horizontal plane.

In at least one embodiment, the guide member extends in a horizontal direction.

According to a second aspect of the present invention, there is provided a parallel mechanism assembly, which is characterized in that it comprises a bridge assembly and two multi-degree-of-freedom parallel mechanisms according to the present invention, and the two positioning mechanisms of the two multi-degree-of-freedom parallel mechanisms The platforms are all rotatably connected with the bridge assembly, so that the bridge assembly can rotate about two non-parallel axes relative to any one of the positioning platforms, and the bridge assembly has at least three translational degrees of freedom and two rotations Degrees of freedom.

In at least one embodiment, the two axes on which the bridge assembly rotates relative to each of the positioning platforms are perpendicular to each other.

The multi-degree-of-freedom parallel mechanism according to the present invention has a compact structure and a large range of movement in the vertical direction, and the parallel mechanism assembly according to the present invention has a simple structure and convenient control.

Description of the drawings

1 and 2 are schematic diagrams of a multi-degree-of-freedom parallel mechanism according to the first embodiment of the present invention.

Fig. 3 is a schematic diagram of a multi-degree-of-freedom parallel mechanism according to a second embodiment of the present invention.

Fig. 4 is a schematic diagram of a multi-degree-of-freedom parallel mechanism according to a third embodiment of the present invention.

Fig. 5 is a schematic diagram of a multi-degree-of-freedom parallel mechanism according to a fourth embodiment of the present invention.

Fig. 6 is a schematic diagram of a parallel mechanism assembly according to an embodiment of the present invention.

Fig. 7 is a schematic diagram of a parallel mechanism assembly according to an embodiment of the present invention.

Description of reference signs:

G guide;

1 first-level branch chain; 11 driving parts; 12 branch chain platforms; 121 base stations; 122 turntables;

2 secondary branch chain; 20 positioning platform; 20p pick-up fittings;

L11 first level first; L12 first second; L13 first third; L14 first fourth; L21 second second; L22 second second; L23 second third; L24 Second-level fourth shot;

3 bridge components; M terminal work piece; b1 branch chain shaft; b2 positioning platform rotation axis; a1, a2 rotation axis.

Detailed ways

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present invention, and are not used to exhaust all possible ways of the present invention, nor are they used to limit the scope of the present invention.

Unless otherwise specified, the present invention uses the three-dimensional coordinate system shown in FIGS. 1 to 7 to illustrate the positional relationship of each component. It should be understood that the position relationship defined according to the x, y, and z axes in the present invention is relative, and the coordinate axis can be rotated in space according to the actual application of the device.

(The first embodiment of the multi-degree-of-freedom parallel mechanism)

The first embodiment of the multi-degree-of-freedom parallel mechanism of the present invention will be described with reference to FIGS. 1 and 2.

The parallel mechanism according to the first embodiment of the present invention includes a guide G, two primary branches 1 and one secondary branch 2.

Each primary side chain 1 includes two driving parts 11, a side chain platform 12 and a plurality of primary links connecting the driving parts 11 and the side chain platform 12. The secondary branch 2 includes a positioning platform 20 and a plurality of secondary linkages, and the secondary linkages are used to connect the positioning platform 20 and the two branch platforms 12 of the primary branch 1.

In this embodiment, the guide member G extends along the x direction, and the active member 11 can reciprocate along the guide member G. The primary branch chain 1 moves in the xoz plane (also called the first plane), and the secondary branch chain 2 moves in the xoy plane (also called the second plane). Preferably, the first plane is a vertical plane, and the second plane For the horizontal plane. By driving any one or more of the four active parts 11 to move along the guide G, the position of the positioning platform 20 at the end of the secondary branch 2 in the three-dimensional coordinate system can be changed, that is, the positioning platform of the secondary branch 2 20 has three translational degrees of freedom in the x-direction, y-direction, and z-direction.

The first-stage link in this embodiment includes a first-stage first lever L11, a first-stage second lever L12, a first-stage third lever L13, and a first-stage fourth lever L14. The first-level first lever L11, the first-level second lever L12, an active member 11 and the branch chain platform 12 form a parallelogram structure, the first-level third lever L13, the first-level fourth lever L14, and the other active member 11 and support The chain platform 12 forms another parallelogram structure.

Specifically, the two ends of the first-level first lever L11 are rotatably connected to the first-level first point O11 and the first-level second point O12 with the active member 11 and the branch chain platform 12, and the two ends of the first-level second lever L12 are respectively connected to The driving part 11 and the branch chain platform 12 are rotatably connected to the first-level third point O13 and the first-level fourth point O14, which are sequentially connected to the first-level first point O11, the first-level second point O12, the first-level fourth point O14, and the first-level fourth point O14. The quadrilateral obtained by the third point O13 of the first level is a parallelogram; the two ends of the third lever L13 of the first level are respectively connected to the fifth point O15 of the first level and the sixth point O16 of the first level with the driving member 11 and the branch chain platform 12 respectively. The two ends of the fourth lever L14 are respectively connected to the first-level seventh point O17 and the first-level eighth point O18 with the driving member 11 and the branch chain platform 12 respectively, and are sequentially connected to the first-level fifth point O15 and the first-level sixth point O16. The quadrilateral obtained by the eighth point O18 at the first level and the seventh point O17 at the first level is a parallelogram.

In this embodiment, the first-level second point O12 and the first-level sixth point O16 overlap (the two points are on the same rotation axis), the first-level fourth point O14 and the first-level eighth point O18 overlap, so it can also be It is said that the first-level third rod L13 is connected to the first-level first rod L11, and the first-level fourth rod L14 is connected to the first-level second rod L12. In this case, it can also be said that the first-level third lever L13 is rotationally connected to the branch chain platform 12, and the first-level fourth rod L14 is rotationally connected to the branch chain platform 12. Of course, as easily understood by those skilled in the art, the first-level third rod L13 may not be connected to the first-level first rod L11 but to other parts of the branch chain platform 12, and the first-level fourth rod L14 may not be connected to the first rod L11. Instead, the second lever L12 is connected to other parts of the branch chain platform 12.

In this embodiment, the guide member G extends along the x direction, and the active member 11 can reciprocate along the guide member G. The primary link is parallel to the xoz plane, that is, as the position of the driving member 11 on the guide G changes, the two parallelograms change their shape and/or position in the xoz plane, so that they are aligned with the two parallelograms. The connected branch chain platforms 12 can move in translation in the x-direction and z-direction.

The secondary connecting rod in this embodiment includes a secondary first rod L21, a secondary second rod L22, a secondary third rod L23, and a secondary fourth rod L24. The second-level first rod L21, the second-level second rod L22 and the positioning platform 20 and a branch chain platform 12 form a parallelogram structure, the second-level third rod L23, the second-level fourth rod L24 and the positioning platform 20 and the other support The chain platform 12 forms another parallelogram structure.

Specifically, the two ends of the second-level first rod L21 are respectively rotatably connected with a branch chain platform 12 and the positioning platform 20 to the second-level first point O21 and the second-level second point O22, and the two ends of the second-level second rod L22 are respectively It is rotatably connected to the second-level third point O23 and the second-level fourth point O24 with a branch chain platform 12 and the positioning platform 20, and sequentially connected to the second-level first point O21, the second-level second point O22, and the second-level fourth point O24 The quadrilateral obtained from the second-level third point O23 is a parallelogram; the two ends of the second-level third lever L23 are respectively connected to the second-level fifth point O25 and the second-level sixth point with the other branch chain platform 12 and the positioning platform 20 respectively. O26, the two ends of the second-level fourth lever L24 are respectively connected to the second-level seventh point O27 and the second-level eighth point O28 with the other branch chain platform 12 and the positioning platform 20 respectively, and sequentially connected to the second-level fifth point O25, The quadrilateral obtained by the second-level sixth point O26, the second-level eighth point O28, and the second-level seventh point O27 is a parallelogram.

In this embodiment, the second-level second point O22 and the second-level sixth point O26 overlap, and the second-level fourth point O24 and the second-level eighth point O28 overlap. Therefore, it can also be said that the second-level third rod L23 is connected to The second-level first rod L21 and the second-level fourth rod L24 are connected to the second-level second rod L22.

The secondary link is parallel to the xoy plane. As the position of the driving member 11 on the guide G changes, the two parallelograms in the secondary branch 2 can both change their shape and/or position in the xoy plane, so that The positioning platform 20 connected to the two parallelograms can move in the x-direction and the y-direction. In addition to the movement transmitted by the first-level branch chain 1, the positioning platform 20 has three directions in x, y, and z. Translational degrees of freedom.

Preferably, a terminal work piece M is provided on the positioning platform 20, and the terminal work piece M can be used to perform operations of a specific function, for example. The present invention does not limit the position and direction of the terminal work piece M on the positioning platform 20.

(The second embodiment of the multi-degree-of-freedom parallel mechanism)

The second embodiment of the multi-degree-of-freedom parallel mechanism of the present invention will be described with reference to FIG. 3. This embodiment is a modification of the first embodiment. The difference from the first embodiment mainly includes the arrangement of the connecting rod. In this embodiment, the same or similar parts as in the first embodiment use the same reference numerals. In this embodiment, two asymmetric primary branches 1 are used to illustrate the possible different arrangements of the connecting rods.

First, refer to the primary branch 1 on the left in FIG. 3. In the first-level branch chain 1, the two ends of the first-level third lever L13 are rotatably connected to the first-level fifth point O15 and the first-level sixth point O16 with the driving member 11 and the first-level first rod L11, of which the first-level The sixth point O16 is located in the middle of the first-level first lever L11 and does not coincide with the first-level second point O12; the two ends of the first-level fourth lever L14 are respectively rotatably connected with the driving member 11 and the first-level second lever L12. The seventh point O17 and the first-level eighth point O18, of which the first-level eighth point O18 is located in the middle of the first-level second lever L12 and does not coincide with the first-level fourth point O14. The quadrilateral obtained by sequentially connecting the first-level fifth point O15, the first-level sixth point O16, the first-level eighth point O18, and the first-level seventh point O17 is a parallelogram.

The above arrangement makes it possible that in the same space, the two active parts 11 of the primary branch 1 have a larger moving space and are not easy to interfere with each other or with other surrounding components.

Next, referring to the primary branch 1 on the right in FIG. 3, compared to the primary branch 1 on the left, the primary branch 1 on the right does not have the primary fourth lever L14. That is, in the first-level branch chain 1, the first-level third rod L13 that connects the active member 11 and the first-level first rod L11 can determine the limit defined by the first-level first rod L11 and the first-level second rod L12. The posture of the parallelogram can achieve the purpose of determining the position of the branch chain platform 12 in the xoz plane.

This arrangement further reduces the number of components in the primary branch chain 1 and makes the primary branch chain 1 lighter and more compact.

It is worth noting that there is another modification of the primary branch 1 on the right side of FIG. 3. In this modification, the rotational connection point of the primary third lever L13 and the primary first lever L11, that is, the primary The sixth point O16 may also coincide with the first-level second point O12. In other words, this modification is equivalent to omitting the first-level fourth lever L14 in the first embodiment. This arrangement can also determine the posture of the parallelogram defined by the first-level first lever L11 and the first-level second lever L12.

Similarly, the modified setting of the primary link in the primary branch 1 is applicable to the secondary link in the secondary branch 2. That is, only one parallelogram structure may be retained in the secondary branch chain 2. The parallelogram structure includes one branch chain platform 12, and the other branch chain platform 12 is connected to only one link in the parallelogram structure by a link. Or, the secondary branch 2 still retains two parallelogram structures, but one of the parallelogram structures includes the positioning platform 20, and the link in the other parallelogram structure is not connected to the positioning platform 20, but is connected to the previous one The secondary link in a parallelogram structure.

As those skilled in the art can easily understand, although reducing the number of links in the branch chain can make the mechanism occupy a smaller space, the redundant parallelogram structure formed by a larger number of links can increase the stability of the guiding mechanism. sex.

(The third embodiment of the multi-degree-of-freedom parallel mechanism)

The third embodiment of the multi-degree-of-freedom parallel mechanism of the present invention will be described with reference to FIG. 4. This embodiment is a modification of the first embodiment. The difference from the first embodiment mainly includes the arrangement of the branch chain platform 12. In this embodiment, the same or similar parts as in the first embodiment use the same reference numerals.

In this embodiment, the branch chain platform 12 includes a base 121 and a turntable 122. The base 121 is connected to the primary link, and the turntable 122 is connected to the secondary link. The turntable 122 can rotate relative to the base 121 around the branch chain shaft b1. Rotate. The branch rotation axis b1 is parallel to the xoy plane, and in the present embodiment, preferably, the branch rotation axis b1 is parallel to the y direction.

The increased rotational freedom of the branch chain platform 12 reduces the kinematic coupling degree of the multi-degree-of-freedom parallel mechanism in this embodiment in all directions, the parallel mechanism has a larger range of motion, and enables the positioning platform 20 to achieve four degrees of freedom. Specifically, when each driving member 11 moves along the guide G to the two branch chain platforms 12 having different positions in the z direction, the branch chain platform 12, that is, the secondary branch chain 2 rotates around the y direction, therefore, The positioning platform 20 has translational degrees of freedom in the x, y, and z directions and rotational degrees of freedom around the y direction.

Since the rotating structure is arranged at the end of the primary branch 1 connected to the secondary branch 2, the rotating structure is far from the positioning platform 20 at the end of the multi-degree-of-freedom parallel mechanism, which enables the positioning platform 20 to have rotational freedom at the same time It can also have a lightweight and compact structure.

(The fourth embodiment of the multi-degree-of-freedom parallel mechanism)

The fourth embodiment of the multi-degree-of-freedom parallel mechanism of the present invention will be described with reference to FIG. 5. This embodiment is a modification of the third embodiment.

In this embodiment, the positioning platform 20 includes a terminal positioning platform 21 and two rotating positioning platforms 22. Each rotating positioning platform 22 can rotate relative to the terminal positioning platform 21 about the positioning platform rotation axis b2. In this embodiment, the positioning platform rotation axis b2 is parallel to the z direction. The rotating connection point between the secondary connecting rod and the positioning platform 20 is located on the rotating positioning platform 22.

In this embodiment, the terminal positioning platform 21 has translational degrees of freedom in the three directions of x, y, and z, as well as degrees of freedom of rotation around the z direction.

It should be understood that the positioning platform rotation axis b2 may also be set to be parallel to the x direction or parallel to the y direction, so that the terminal positioning platform 21 has a degree of freedom of rotation around the x direction or a degree of freedom of rotation around the y direction.

It is worth noting that, in this embodiment, the two rotating positioning platforms 22 can be separated by a certain distance in the z direction, so that the two rotating positioning platforms 22 and the secondary connecting rods connected to it will not be rotated during the rotation. Interference occurs, in other words, this causes the terminal positioning platform 21 to have a greater rotation amplitude.

(Parallel mechanism components)

Next, the parallel mechanism assembly according to the present invention will be described with reference to FIGS. 6 and 7. The parallel mechanism assembly according to the present invention includes two multi-degree-of-freedom parallel mechanisms D according to the present invention, and also includes a bridge assembly 3.

First, referring to Figure 6, the two positioning platforms 20 of the two multi-degree-of-freedom parallel mechanisms D are both rotatably connected to the bridge assembly 3, and the bridge assembly 3 relative to each positioning platform 20 can move around two non-parallel (preferably The rotation axes a1 and a2, which are perpendicular to each other, rotate. In this embodiment, when the movements of the two positioning platforms 20 are synchronized, that is, when the positions of the two positioning platforms 20 in the xoy plane are the same, the rotation axis a1 is parallel to the x direction, and the rotation axis a2 is parallel to the y direction.

By controlling the positions of the eight active parts 11 of the multi-degree-of-freedom parallel mechanism D on their respective guide parts G, the positions of the two positioning platforms 20 in the x, y and z directions can be controlled, thereby realizing the bridge assembly 3 in the x direction The translational movement on the upper side, the translational movement in the y direction, the translational movement in the z direction, the rotation around the x direction and the rotation around the y direction make the bridge assembly 3 have five degrees of freedom.

Preferably, a terminal work piece M is provided on the bridge assembly 3, and the terminal work piece M is, for example, a surgical instrument. The present invention does not limit the position and direction of the terminal work piece M on the bridge assembly 3.

7, when the multi-degree-of-freedom parallel mechanism D included in the parallel mechanism assembly is similar to the fourth embodiment of the above multi-degree-of-freedom parallel mechanism, that is, the positioning platform 20 includes a terminal positioning platform 21 and two rotational positioning platforms 22. Each rotation positioning platform 22 can rotate relative to the terminal positioning platform 21 about the rotation axis b2, and the rotation axis b2 in this embodiment is parallel to the z direction. Then, the bridge assembly 3 will have six degrees of freedom (the translational degrees of freedom in the x, y, and z directions and the rotational degrees of freedom around the x, y, and z directions).

The present invention does not limit the number of guides G in the parallel mechanism assembly.

It should be understood that the above-mentioned embodiments and part of their aspects or features can be combined as appropriate.

The following briefly describes some of the beneficial effects of the above-mentioned embodiments of the present invention.

(i) According to the multi-degree-of-freedom parallel mechanism of the present invention, the movement of the primary branch 1 in the z direction (for example, the vertical direction) and the movement of the secondary branch 2 in the z direction do not restrict each other, so that the positioning platform 20 has a large range of motion in the z direction.

(ii) The active parts 11 of the multi-degree-of-freedom parallel mechanism according to the present invention can be arranged on a guide G, making the structure of the parallel mechanism more compact.

(iii) The parallel mechanism assembly according to the present invention has a simple structure and convenient control, and can realize at least three translational and two rotational degrees of freedom.

It should be understood that the above-mentioned embodiments are only exemplary and are not used to limit the present invention. Those skilled in the art can make various modifications and changes to the above-mentioned embodiments under the teaching of the present invention without departing from the scope of the present invention. E.g,

(i) The parallel mechanism or parallel mechanism assembly according to the present invention is preferably used as a part of a surgical robot, but the present invention is not limited to this. The parallel mechanism or parallel mechanism assembly according to the present invention can also provide guidance for other instruments.

When a terminal work piece M is added to the positioning platform 20 or the bridge assembly 3, the terminal work piece M can have an additional degree of freedom relative to the positioning platform 20 or the bridge assembly 3.

(ii) The guide G of the present invention is not limited to the form of the guide rail as shown in the figure, but may also be a guide in other forms such as a guide groove or a screw rod.

(iii) The guide G may not extend along a straight line, for example, it may be a guide path in the form of a curve.

(iv) The two primary branches 1 of the multi-degree-of-freedom parallel mechanism according to the present invention may not be symmetrical, and the two parts of the secondary branch 2 connecting the primary branch 1 may not be symmetrical.

Claims

A multi-degree-of-freedom parallel mechanism, which includes a guide (G), two primary branches (1) and one secondary branch (2), wherein,

Each of the first-level branch chains (1) includes two active parts (11), a branch-chain platform (12) and a plurality of first-level parts connecting the active parts (11) and the branch-chain platform (12) The connecting rod, the active member (11) can reciprocate along the guide member (G), the secondary branch chain (2) includes a positioning platform (20) and a plurality of connecting the branch chain platforms (12) And the secondary connecting rod of the positioning platform (20),

In each of the first-level branch chains (1), one of the two active elements (11) is connected to the branch chain platform (12) by at least two first-level links , The two ends of the first-level first rod (L11) are respectively rotatably connected to the first-level first point (O11) and the first-level second point ( O12), the two ends of the first-level second lever (L12) are respectively rotatably connected to the first-level third point (O13) and the first-level fourth point ( O14), connect the first-level first point (O11), the first-level second point (O12), the first-level fourth point (O14), and the first-level third point (O13) in sequence to obtain The quadrilateral of is a parallelogram parallel to the first plane (xoz); the other of the two active members (11) is connected to the branch chain by at least one of the primary links The platform (12) or the first-level first rod (L11) determines the posture of the parallelogram defined by the first-level first rod (L11) and the first-level second rod (L12),

In the secondary side chain (2), one of the two side chain platforms (12) is connected to the positioning platform (20) by at least two secondary links, The two ends of the secondary first rod (L21) are respectively rotatably connected with the branch chain platform (12) and the positioning platform (20) to the secondary first point (O21) and the secondary second point (O22). ), the two ends of the secondary second lever (L22) are respectively connected to the branch chain platform (12) and the positioning platform (20) to be rotatably connected to the secondary third point (O23) and the secondary fourth point (O24) ), which is obtained by sequentially connecting the second-level first point (O21), the second-level second point (O22), the second-level fourth point (O24), and the second-level third point (O23) The quadrilateral is a parallelogram capable of moving in the second plane (xoy); the other one of the two branch chain platforms (12) is connected to each other through at least one of the two-stage connecting rods. The positioning platform (20) or the second-level first rod (L21) to determine the posture of the parallelogram defined by the second-level first rod (L21) and the second-level second rod (L22),

The first plane (xoz) is not parallel to the second plane (xoy), and the guide (G) is parallel to the second plane (xoy),

The positioning platform (20) has at least three translational degrees of freedom.
The multi-degree-of-freedom parallel mechanism according to claim 1, wherein the first plane (xoz) is perpendicular to the second plane (xoy).
The multi-degree-of-freedom parallel mechanism according to claim 1, characterized in that, in each of the first-level branch chains (1), the other of the two active parts (11) is ) Is connected to the first-level first rod (L11) through the first-level third rod (L13), and both ends of the first-level third rod (L13) are respectively connected to the active part (11) and the first-level first rod (L13) A rod (L11) is rotatably connected to the fifth point (O15) of the first level and the sixth point (O16) of the first level, and the sixth point (O16) of the first level does not coincide with the first point (O11) of the first level,

The other of the two side chain platforms (12) is connected to the second level first bar (L21) through a second level third bar (L23), the second level third bar The two ends of (L23) are respectively rotatably connected to the second-level fifth point (O25) and the second-level sixth point (O26) with the branch chain platform (12) and the second-level first rod (L21). The second-level sixth point (O26) does not coincide with the second-level first point (O21).
The multi-degree-of-freedom parallel mechanism according to claim 3, wherein the sixth point (O16) of the first level coincides with the second point (O12) of the first level, and/or

The second-level sixth point (O26) coincides with the second-level second point (O22).
The multi-degree-of-freedom parallel mechanism according to claim 3, characterized in that, in each of the first-level branch chains (1), the other of the two active parts (11) is ) Is also connected to the first-level second rod (L12) through the first-level fourth rod (L14), and both ends of the first-level fourth rod (L14) are respectively connected to the active part (11) and the first-level The second rod (L12) is rotatably connected to the seventh point (O17) of the first level and the eighth point (O18) of the first level, and sequentially connected to the fifth point (O15) of the first level and the sixth point of the first level (O16). ), the quadrilateral obtained by the eighth point (O18) of the first level and the seventh point (O17) of the first level is a parallelogram, and/or

The other side chain platform (12) of the two side chain platforms (12) is also connected to the second level second bar (L22) through the second level fourth bar (L24), and the second level fourth bar (L24) is connected to the second level bar (L22). The two ends of the rod (L24) are respectively rotatably connected with the branch chain platform (12) and the second-level second rod (L22) to the second-level seventh point (O27) and the second-level eighth point (O28). The quadrilateral obtained by connecting the second-level fifth point (O25), the second-level sixth point (O26), the second-level eighth point (O28) and the second-level seventh point (O27) is parallel quadrilateral.
The multi-degree-of-freedom parallel mechanism according to claim 1, characterized in that four active parts (11) share one guide part (G).
The multi-degree-of-freedom parallel mechanism according to any one of claims 1 to 6, wherein the branch chain platform (12) comprises a base (121) and a turntable (122), and the turntable (122) can Relative to the abutment (121) to rotate around the branch chain shaft (b1),

The primary link is connected to the abutment (121), and the secondary link is connected to the turntable (122).
The multi-degree-of-freedom parallel mechanism according to claim 7, wherein the branch chain shaft (b1) is parallel to the second plane (xoy).
The multi-degree-of-freedom parallel mechanism according to any one of claims 1 to 6, wherein the positioning platform (20) comprises a terminal positioning platform (21) and two rotating positioning platforms (22), and the rotating The positioning platform (22) is rotationally connected with the terminal positioning platform (21), the rotational connection point of the secondary link and the positioning platform (20) is located on the rotational positioning platform (22), and each rotation The positioning platforms (22) are capable of rotating relative to the terminal positioning platform (21) around the positioning platform rotation axis (b2), and the terminal positioning platform (21) has at least three translational degrees of freedom and one rotational degree of freedom.
The multi-degree-of-freedom parallel mechanism according to claim 9, characterized in that the rotation axis (b2) of the positioning platform is perpendicular to the second plane (xoy).
The multi-degree-of-freedom parallel mechanism according to any one of claims 1 to 6, wherein the first plane (xoz) is a vertical plane, and the second plane (xoy) is a horizontal plane.
The multi-degree-of-freedom parallel mechanism according to any one of claims 1 to 6, wherein the guide (G) extends in a horizontal direction.
A parallel mechanism assembly, characterized in that it comprises a bridge assembly (3) and two multi-degree-of-freedom parallel mechanisms (D) according to any one of claims 1 to 12, two of the multi-degree-of-freedom parallel mechanisms The two positioning platforms (20) of (D) are both rotatably connected to the bridge assembly (3), so that the bridge assembly (3) can move around two different positions relative to any one of the positioning platforms (20). The parallel axes (a1, a2) rotate, and the bridge assembly (3) has at least three translational degrees of freedom and two rotational degrees of freedom.
The parallel mechanism assembly according to claim 13, wherein the two axes (a1, a2) on which the bridge assembly (3) rotates relative to each of the positioning platforms (20) are perpendicular to each other.