CN201824354U - Decoupled six-DOF (degree of freedom) parallel mechanism - Google Patents

Abstract

A decoupled six-degree-of-freedom parallel mechanism includes a frame, a moving platform, and three motion branch chains with the same structure connected between the frame and the moving platform. Each of the three kinematic branch chains includes sequentially connected first moving pair, second moving pair, third moving pair, first rotating pair, second rotating pair and third rotating pair; wherein the first moving pair is connected to the frame, The third rotation pair is connected with the moving platform through a connecting rod; the axis direction of the first movement pair, the axis direction of the second movement pair and the axis direction of the third movement pair are in a three-dimensional orthogonal distribution; the first rotation The axial direction of the pair, the axial direction of the second rotating pair and the axial direction of the third rotating pair are three-dimensionally distributed; the first rotating pair is coaxially connected with the third moving pair. The utility model has decoupled three degrees of freedom of movement and three degrees of freedom of rotation, each degree of freedom only depends on a single active pair control, the realization principle is very simple, and has a very good linear relationship.

Description

Decoupled Six Degrees of Freedom Parallel Mechanism

technical field

The utility model relates to a machine tool and an industrial robot, in particular to a six-degree-of-freedom parallel mechanism used for decoupling a virtual axis numerical control machine tool with a parallel structure and a parallel robot.

Background technique

Parallel mechanisms are widely used in heavy-duty simulation equipment, robots, CNC machine tools, sensors and micro-operation fields. However, the drive units of the parallel mechanism are coupled, that is, the movement of the overall output platform of the parallel mechanism in any direction is the synthesis of the motions of all drive units, and the movement of each drive unit is combined with the overall movement of the parallel mechanism (i.e. input and output ) is non-linear. This characteristic leads to complex control of parallel mechanism, difficult calibration, and restricts the improvement of accuracy. Therefore, how to achieve decoupling of parallel mechanisms to simplify control and calibration and improve motion accuracy has always been a difficult and challenging subject.

The motion decoupling parallel robot means that any degree of freedom of the output motion depends only on a single drive unit, and the actions of other drive units do not affect this degree of freedom. The parallel mechanism with complete decoupling has simple kinematic relationship, easy calibration, high control precision and high rigidity, and has broad application prospects in virtual axis machine tools and robots.

The patent document (publication number: CN1261018A) reports the decoupling of a parallel mechanism at one position in space (ie, the initial position), but other positions are still coupled, so this technology belongs to instantaneous decoupling. Chinese invention patents ZL00100198.1, ZL00100197.3, ZL00100196.5 and ZL99121020.4 report decoupling parallel mechanisms in the micro-motion field. With the increase of the working space, the decoupling between the driving units is lost. The patent literature with publication number CN1462673A reports a parallel mechanism with unconditional decoupling of five degrees of freedom and conditional decoupling of six degrees of freedom, not a parallel mechanism with complete decoupling of six degrees of freedom. Patent literature with publication number CN1263807A reports a A six-degree-of-freedom decoupled parallel mechanism driven by a moving pair. Although its kinematics is a linear equation, it still does not conform to a single output degree of freedom and depends on a single driver. It does not belong to a completely decoupled six-degree-of-freedom parallel mechanism. A completely decoupled The literature and inventions of six-degree-of-freedom parallel mechanisms have not yet been retrieved.

Utility model content

The purpose of this utility model is to overcome the defects of the above-mentioned prior art, and provide a six-degree-of-freedom parallel connection for decoupling virtual-axis machine tools and robots with simple structure, convenient installation, easy calibration, simple control, and low cost. mechanism.

In order to achieve the above purpose, the utility model adopts the following technical solutions: a decoupled six-degree-of-freedom parallel mechanism, which consists of a frame, a moving platform, and a first kinematic branch chain connected between the frame and the moving platform, and a second Composed of kinematic branch chain and third kinematic branch chain;

The first kinematic branch chain, the second kinematic branch chain and the third kinematic branch chain have the same structure, and each includes a first moving pair, a second moving pair, a third moving pair and a first moving pair sequentially connected through corresponding connecting rods. Rotating pair, second rotating pair and third rotating pair; wherein the first moving pair is connected with the frame, and the third rotating pair is connected with the moving platform through a connecting rod; the axis direction of the first moving pair, the second moving pair The axis direction of the pair and the axis direction of the third moving pair are distributed in a three-dimensional orthogonal manner; the axis direction of the first rotating pair, the axis direction of the second rotating pair and the axis direction of the third rotating pair are distributed in a three-dimensional orthogonal manner; The first rotating pair is coaxially connected with the third moving pair.

The first rotation pair in the first kinematic branch chain, the third rotation pair in the second kinematic branch chain, and the second rotation pair in the third kinematic branch chain are located on the same axis;

The second rotation pair in the first kinematic branch chain, the first rotation pair in the second kinematic branch chain and the third rotation pair in the third kinematic branch chain are located on the same axis;

The third rotary pair in the first kinematic branch chain, the second rotary pair in the second kinematic branch chain, and the first rotary pair in the third kinematic branch chain are located on the same axis;

The above three axes intersect at one point, which is the center of the moving platform.

The axis directions of the three first rotating pairs of the three motion branch chains are three-dimensionally orthogonally distributed; the axis directions of the three second rotating pairs of the three motion branch chains are three-dimensionally orthogonally distributed; The axis directions of the three third rotating pairs of the three kinematic branch chains are three-dimensionally orthogonally distributed.

The first moving pair in the first branched chain of motion is perpendicular to the first moving pair in the second branched chain of motion and parallel to the first moving pair in the third branched chain of motion; The second moving pair in the second kinematic branch chain is parallel to the second moving pair in the second kinematic branch chain and perpendicular to the second moving pair in the third kinematic branch chain; the third moving pair in the first kinematic branch chain, the The axis directions of the third moving pair in the second kinematic branch chain and the third moving pair in the third kinematic branch chain are three-dimensionally orthogonally distributed.

Compared with the prior art, the decoupled six-degree-of-freedom parallel mechanism of the utility model has the following advantages and characteristics due to the adoption of the above technical scheme:

1. It has three degrees of freedom of rotation and three degrees of freedom of movement that are completely decoupled, and each degree of freedom only depends on a single active pair control, and the position movement of the mechanism is completely isolated from the change of attitude, and has a very good linear relationship;

2. Contains only a few kinematic pairs, simple structure, convenient installation, small moment of inertia, and fast motion response.

3. Motion decoupling, basically a single output degree of freedom only needs to control a single drive unit, which is easy to calibrate and control, thus reducing development costs.

Description of drawings

Fig. 1 is a three-dimensional structural schematic diagram of the decoupled six-degree-of-freedom parallel mechanism of the present invention (wherein the frame is omitted).

Detailed ways

Below in conjunction with specific embodiment, further set forth the utility model. The drawings show a preferred embodiment of the utility model, and the technical solution of the utility model is not limited to this embodiment.

Referring to Fig. 1, the decoupled six-degree-of-freedom parallel mechanism of the utility model consists of a frame (not shown), a moving platform 4 and a first motion branch chain 1 connected between the frame and the moving platform, and the second motion The branch chain 2 and the third movement branch chain 3 are composed.

The first kinematic branch chain 1, the second kinematic branch chain 2 and the third kinematic branch chain 3 in the utility model have the same structure.

The first kinematic branch chain 1 includes the first moving pair 11, the second moving pair 12, the third moving pair 13, the first rotating pair 14, the second rotating pair 15 and the third rotating pair connected sequentially through corresponding connecting rods. A pair 16; wherein the first moving pair 11 is connected to the frame, and the third rotating pair 16 is connected to the moving platform 4 through a connecting rod. The axial direction of the first movable pair 11, the axial direction of the second movable pair 12 and the axial direction of the third movable pair 13 are three-dimensional orthogonal distribution; the axial direction of the first rotating pair 14, the axial direction of the second rotating pair 15 and The axis direction of the third rotating pair 16 is three-dimensionally distributed orthogonally; the first rotating pair 14 is coaxially connected with the third moving pair 16 .

The second kinematic branch chain 2 includes a first moving pair 21, a second moving pair 22, a third moving pair 23, a first rotating pair 24, a second rotating pair 25, and a third rotating pair 26, which are sequentially connected through corresponding connecting rods. ; The first moving pair 21 is connected to the frame, and the third rotating pair 26 is connected to the moving platform 4 through the connecting rod. The axial direction of the first movable pair 21, the axial direction of the second movable pair 22 and the axial direction of the third movable pair 23 are three-dimensional orthogonal distribution; the axial direction of the first rotating pair 24, the axial direction of the second rotating pair 25 and The axis direction of the third rotating pair 26 is three-dimensionally distributed; the first rotating pair 24 is coaxially connected with the third moving pair 26 .

The third kinematic branch chain 3 includes a first moving pair 31, a second moving pair 32, a third moving pair 33, a first rotating pair 34, a second rotating pair 35 and a third rotating pair 36 connected sequentially through corresponding connecting rods. ; The first moving pair 31 is connected to the frame, and the third rotating pair 36 is connected to the moving platform 4 through a connecting rod. The axial direction of the first movable pair 31, the axial direction of the second movable pair 32 and the axial direction of the third movable pair 33 are three-dimensional orthogonal distribution; the axial direction of the first rotating pair 34, the axial direction of the second rotating pair 35 and The axis direction of the third rotating pair 36 is three-dimensionally distributed; the first rotating pair 34 is coaxially connected with the third moving pair 36 .

The first rotation pair 14 in the first kinematic branch chain 1 , the third rotation pair 26 in the second kinematic branch chain 2 and the second rotation pair 35 in the third kinematic branch chain are located on the same axis.

The second rotation pair 15 in the first kinematic branch chain 1 , the first rotation pair 24 in the second kinematic branch chain 2 and the third rotation pair 36 in the third kinematic branch chain 3 are located on the same axis.

The third rotation pair 16 in the first kinematic branch chain 1 , the second rotation pair 25 in the second kinematic branch chain 2 and the first rotation pair 34 in the third kinematic branch chain 3 are located on the same axis.

The above-mentioned three axes intersect at one point, which is the center of the moving platform 4 .

The axis directions of the three first revolving pairs 14, 24, 34 of the above-mentioned three kinematic branch chains are three-dimensionally orthogonal; the axis directions of the three second rotating pairs 15, 25, 35 of the three kinematic branch chains are three-dimensionally Intersecting distribution; the axis directions of the three third rotating pairs 16, 26, 36 of the three kinematic branch chains are in a three-dimensional orthogonal distribution.

The first mobile pair 11 in the above-mentioned first kinematic branch chain 1 is perpendicular to the first mobile pair 21 in the second kinematic branch chain 2 and parallel to the first mobile pair 31 in the third kinematic branch chain 3; The second mobile pair 12 in the chain 1 is parallel to the second mobile pair 22 in the second kinematic branch chain 2 and perpendicular to the second mobile pair 32 in the third kinematic branch chain 3; the second mobile pair 32 in the first kinematic branch chain 1 The axis directions of the three moving pairs 13 , the third moving pair 23 in the second kinematic branch chain 2 and the third moving pair 33 in the third kinematic branch chain 3 are three-dimensionally orthogonally distributed.

The working principle of the decoupled six-degree-of-freedom parallel mechanism of the utility model can be described as follows in conjunction with the drawings: when the first moving pair 11 of the first kinematic branch 1 is elongated or shortened along the axis, the The third moving pair 23 with the same axis direction, the third motion branch chain 3 has the first moving pair 31 with the same axis direction, therefore, the first moving pair 11 of the first motion branch chain 1 can drive the movable platform 4 to move along the first The axis direction of the pair 11 moves.

Similarly, when the first moving pair 21 of the second kinematic branch chain 1 is elongated or shortened along the axis, since the first kinematic branch chain 1 has the third moving pair 13 with the same axis direction, the third kinematic branch chain 3 has an axis The second moving pair 32 in the same direction, therefore, the first moving pair 21 of the second kinematic branch chain 2 can drive the moving platform 4 to move along the axis direction of the second moving pair 21 . When the first moving pair 31 of the third kinematic branch chain 1 is elongated or shortened along the axis, since the first kinematic branch chain 1 has the third moving pair 11 with the same axis direction, the second kinematic branch chain 2 has the same axis direction. The third moving pair 23 , therefore, the first moving pair 31 of the third kinematic branch chain 3 can drive the movable platform 4 to move along the axis direction of the third moving pair 31 . It can be seen that the decoupled six-degree-of-freedom parallel mechanism of the present invention has three decoupled degrees of freedom of movement.

When the first rotation pair 14 of the first kinematic branch chain 1 rotated around the axis, due to the third rotation pair 26 of the second kinematic branch chain 2 and the second rotation pair 35 of the third kinematic branch chain 3 and the first kinematic branch chain The first rotating pair 14 of 1 is located on the same axis, so the moving platform 4 can rotate around its axis driven by the first rotating pair 14 of the first kinematic branch chain 1 . Similarly, when the first rotation pair 24 of the second motion branch chain 2 rotates around the axis, or when the first rotation pair 34 of the third motion branch chain 3 rotates around the axis, the movable platform 4 can be driven to rotate around the corresponding axis respectively. The axis of the vice rotates. Therefore, the decoupled six-degree-of-freedom parallel mechanism of the present invention has three decoupled rotational degrees of freedom.

Therefore, the decoupled six-degree-of-freedom parallel mechanism of the utility model has three degrees of freedom of rotation and three degrees of freedom of movement completely decoupled, a total of six degrees of freedom, and each degree of freedom only depends on a single active pair control, and the mechanism's The position movement is completely isolated from the pose change, with a very good linear relationship.

Claims (4)

1. the six-degree-of-freedom parallel connection mechanism of a decoupling zero, by frame, moving platform and be connected frame and moving platform between first movement branched chain, second movement branched chain and the 3rd movement branched chain are formed; It is characterized in that:

Described first movement branched chain, second movement branched chain are identical with the 3rd movement branched chain structure, respectively comprise first moving sets, second moving sets, three moving sets and first revolute pair, second revolute pair and the 3rd revolute pair that link to each other in proper order by corresponding connecting rod; First moving sets wherein links to each other with frame, and the 3rd revolute pair links to each other with moving platform by connecting rod; The axis direction of the axis direction of described first moving sets, second moving sets and the axis direction of three moving sets are three-dimensional orthogonal and distribute; The axis direction of the axis direction of the axis direction of described first revolute pair, second revolute pair and the 3rd revolute pair is three-dimensional orthogonal and distributes; First revolute pair links to each other with three moving sets is coaxial.

2. the six-degree-of-freedom parallel connection mechanism of decoupling zero as claimed in claim 1, it is characterized in that: first revolute pair in described first movement branched chain, the 3rd revolute pair in second movement branched chain and second revolute pair in the 3rd movement branched chain are positioned on same the axis;

Second revolute pair in described first movement branched chain, first revolute pair in second movement branched chain and the 3rd revolute pair in the 3rd movement branched chain are positioned on same the axis;

The 3rd revolute pair in described first movement branched chain, second revolute pair in second movement branched chain and first revolute pair in the 3rd movement branched chain are positioned on same the axis;

Above-mentioned three axes intersect are in a bit, and this point is the center of moving platform.

3. the six-degree-of-freedom parallel connection mechanism of decoupling zero as claimed in claim 1 is characterized in that: the axis direction of three first revolute pairs of described three movement branched chain is three-dimensional orthogonal and distributes; The axis direction of three second revolute pairs of described three movement branched chain is three-dimensional orthogonal and distributes; The axis direction of three the 3rd revolute pairs of described three movement branched chain is three-dimensional orthogonal and distributes.

4. the six-degree-of-freedom parallel connection mechanism of decoupling zero as claimed in claim 1 is characterized in that: first moving sets in described first movement branched chain is vertical and parallel with first moving sets in the 3rd movement branched chain with first moving sets in second movement branched chain; Second moving sets in described first movement branched chain is parallel with second moving sets in second movement branched chain and vertical with second moving sets in the 3rd movement branched chain; The axis direction of the three moving sets in described first movement branched chain, the three moving sets in second movement branched chain and the three moving sets in the 3rd movement branched chain is three-dimensional orthogonal and distributes.

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