CN115922674A - A Three-DOF Redundant Parallel Terminal Force Control Actuator Based on 2UPR-2RRU Mechanism - Google Patents

Abstract

The invention discloses a three-degree-of-freedom redundant parallel terminal force control actuator based on a 2UPR‑2RRU mechanism, including a fixed platform, a moving platform, a terminal tool, a first branch chain, a second branch chain, a third branch chain and a first branch chain. Four branch chains; the terminal tool is set on the moving platform; the moving platform is connected with the fixed platform through the first branch chain, the second branch chain, the third branch chain and the fourth branch chain; the first branch chain and the third branch chain It is a UPR branch; the second branch and the fourth branch are RRU branches. The moving platform in the present invention is output by a three-degree-of-freedom movement of two rotations and one movement relative to the fixed platform, and has four motion branch chains. The redundant drive is conducive to the improvement of the overall rigidity of the mechanism, and has a compact structure, high bearing capacity and high structural strength. At the same time, the terminal force control actuator of the present invention can be connected to different terminal tools on the moving platform to realize various operation functions, and has a good application prospect.

Description

A Three-DOF Redundant Parallel Terminal Force Control Actuator Based on 2UPR-2RRU Mechanism

technical field

The invention belongs to the field of contact operations, and in particular relates to a three-degree-of-freedom redundant parallel terminal force control actuator based on a 2UPR-2RRU mechanism.

Background technique

For robot force-controlled end effectors in the field of contact operations, such as floating grinding equipment, single-degree-of-freedom mechanisms are mostly used in the prior art, which cannot meet the needs of high-precision polishing of complex curved surfaces; therefore, the realization of two rotations and one movement The three-degree-of-freedom parallel terminal force-controlled actuator has broad application prospects; the three-degree-of-freedom parallel mechanism or device has the advantages of good compactness and high load-carrying capacity, so it has been widely studied.

In addition, in these parallel mechanisms or devices with two rotations and one translation, compared with non-redundant drive parallel mechanisms, redundant drive parallel mechanisms also have the advantages of eliminating singularities and improving mechanism rigidity and dexterity. However, the parallel mechanism or device in the prior art has the defects of too many hinges and a relatively complicated structure.

Contents of the invention

The main purpose of the present invention is to provide a three-degree-of-freedom redundant parallel terminal force control actuator based on a 2UPR-2RRU mechanism to solve the deficiencies in the prior art.

In order to achieve the above main purpose, the present invention provides a three-degree-of-freedom redundant parallel terminal force control actuator based on a 2UPR-2RRU mechanism, including a fixed platform, a moving platform, an end tool, a first branch chain, a second branch chain, The third branch chain and the fourth branch chain; the terminal tool is arranged on the moving platform; the moving platform is connected with the fixed platform through the first branch chain, the second branch chain, the third branch chain and the fourth branch chain;

The first branch chain and the third branch chain are UPR branch chains; the second branch chain and the fourth branch chain are RRU branch chains;

The first branch chain has a first U pair, a first moving pair and a first rotating pair; one end of the first branch chain is connected to the fixed platform through the first U pair, and the other end of the first branch chain is connected to the fixed platform through the first rotating pair. The moving platform is connected; the middle part of the first branch chain forms the first moving pair;

The second branch chain has a second rotating pair, a third rotating pair and a second U pair; one end of the second branch chain is connected to the fixed platform through the second rotating pair, and the other end of the second branch chain is connected to the fixed platform through the second U pair. The moving platform is connected; the middle part of the second branch chain is formed as the third rotating pair;

The third branch chain has the third U pair, the second moving pair and the fourth rotating pair; one end of the third branch chain is connected with the fixed platform through the third U pair, and the other end of the third branch chain is connected with the fixed platform through the fourth rotating pair. The moving platform is connected; the middle part of the third branch forms the second moving pair;

The fourth branch chain has the fifth rotating pair, the sixth rotating pair and the fourth U pair; one end of the fourth branch chain is connected to the fixed platform through the fifth rotating pair, and the other end of the second branch chain is connected to the fixed platform through the fourth U pair. The moving platform is connected; the middle part of the fourth branch chain is formed as the sixth rotating pair;

The first U pair includes the rotation axis $ ₁₁ and the rotation axis $ ₁₂ , and the rotation axis $ ₁₁ and the rotation axis $ ₁₂ intersect perpendicularly; the third U pair includes the rotation axis $ ₃₁ and the rotation axis $ ₃₂ ; the rotation axis $ ₃₁ and the rotation axis $ ₃₂ intersect perpendicularly, the rotation axis $ ₁₁ and the rotation axis $ ₃₁ coincide; the rotation axis $ ₁₂ and the rotation axis $ ₃₂ are parallel to each other;

The rotation axis $ ₁₄ and the rotation axis $ ₁₂ of the first rotation pair are parallel to each other; the rotation axis $ ₃₄ and the rotation axis $ ₃₂ of the fourth rotation pair are parallel to each other; the rotation axis $ ₃₄ and the rotation axis $ ₁₄ are parallel to each other;

The movement axis $ ₁₃ of the first moving pair passes through the intersection of the rotation axis $ ₁₁ and the rotation axis $ ₁₂ , and is perpendicular to the rotation axis $ ₁₂ ; the movement axis $ ₃₃ of the second movement pair passes through the intersection of the rotation axis $ ₃₁ and the rotation axis $ ₃₂ , and perpendicular to the axis of rotation $ ₃₂ ;

The rotation axis $ ₂₁ of the second rotation pair is parallel to the rotation axis $ ₁₁ and the rotation axis $ ₃₁ ; the rotation axis $ ₂₂ of the third rotation pair is parallel to the rotation axis $ ₂₁ ; the rotation axis $ ₄₁ of the fifth rotation pair is parallel to the rotation The axis $ ₁₁ and the rotation axis $ ₃₁ are parallel to each other, and the rotation axis $ ₄₂ of the sixth rotating pair is parallel to the rotation axis $ ₄₁ ;

The second U pair contains the rotation axis $ ₂₃ and the rotation axis $ ₂₄ , the rotation axis $ ₂₃ and the rotation axis $ ₂₄ intersect perpendicularly; the fourth U pair includes the rotation axis $ ₄₃ and the rotation axis $ ₄₄ , the rotation axis $ ₄₃ and the rotation axis $ ₄₄ perpendicularly intersect; the rotation axis $ ₂₃ is collinear with the rotation axis $ ₄₃ ; the rotation axis $ ₂₄ and the rotation axis $ ₄₄ are parallel to each other and arranged symmetrically with respect to the moving platform.

According to another specific embodiment of the present invention, the rotation axis $ ₁₁ and the rotation axis $ ₃₁ pass through the central axis of the fixed platform; the rotation axis $ ₂₃ and the rotation axis $ ₄₃ pass through the central axis of the moving platform.

According to another specific embodiment of the present invention, the first moving pair and the second moving pair use through-type motor assemblies;

The first moving pair includes a first screw mandrel and a first motor matched with the first screw mandrel; the first motor is provided with a first motor fixing frame, and the first motor fixing frame and the first U pair rotate along the rotation axis $ ₁₂ Cooperate;

The second moving pair includes a second screw mandrel and a second motor matched with the second screw mandrel; the second motor is provided with a second motor fixing frame, and the second motor fixing frame and the third U pair rotate along the rotation axis $ ₃₂ Cooperate.

According to another specific embodiment of the present invention, both the first motor and the second motor are located on the side of the positioning platform away from the moving platform.

According to another specific embodiment of the present invention, the second rotating pair is used as the driving pair for the second branch chain motion, and the fifth rotating pair is used as the driving pair for the fourth branch chain motion;

The second branch chain includes a third motor, a first worm and a first worm gear; the first worm is arranged at the output end of the third motor, the first worm and the first worm gear are mated and connected, and the second rotating pair is driven by the first worm gear;

The fourth branch chain includes a fourth motor, a second worm and a second worm gear; the second worm is arranged at the output end of the fourth motor, the second worm and the second worm gear are matingly connected, and the fifth rotating pair is driven by the second worm gear.

According to another specific implementation manner of the present invention, both the third motor and the fourth motor are located on the side of the positioning platform away from the moving platform.

The present invention has the following beneficial effects:

The moving platform in the present invention is output by a three-degree-of-freedom movement of two rotations and one movement relative to the fixed platform, and has four motion branch chains. The redundant drive is conducive to the improvement of the overall rigidity of the mechanism, and has a compact structure, high bearing capacity and high structural strength. At the same time, the terminal force control actuator of the present invention can be connected to different terminal tools on the moving platform to realize various operation functions, and has a good application prospect.

In addition, the present invention adopts the penetrating motor and worm gear transmission mode, which has a more compact structure and has a self-locking function, which is beneficial to improving the stability and accuracy of the movement.

In order to more clearly illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is the first perspective view of the embodiment of the present invention;

Fig. 2 is the second perspective view of the embodiment of the present invention;

Fig. 3 is the distribution figure of four branch chains in the embodiment of the present invention;

Fig. 4 is the structural diagram of the first branch chain in the embodiment of the present invention;

Fig. 5 is the structural diagram of the second branch chain in the embodiment of the present invention;

Fig. 6 is the structural diagram of the third branch chain in the embodiment of the present invention;

Fig. 7 is the structural diagram of the fourth branch in the embodiment of the present invention;

Fig. 8 is a simulation diagram of six different types of motions in the embodiment of the present invention.

Detailed ways

In order to understand the above-mentioned purpose, features and advantages of the present invention more clearly, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

In the following description, many specific details are set forth in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described here, therefore, the protection scope of the present invention is not limited to the specific details disclosed below. EXAMPLE LIMITATIONS.

The embodiment of the present invention provides a three-degree-of-freedom redundant parallel terminal force control actuator based on a 2UPR-2RRU mechanism, as shown in Figure 1-2, including a fixed platform 10, a moving platform 20, a terminal tool 30, and a first branch chain 40. The second branch chain 50, the third branch chain 60 and the fourth branch chain 70; the terminal tool 30 is arranged on the moving platform 20; the moving platform 20 passes through the first branch chain 40, the second branch chain 50, and the third branch chain 60 and the fourth branch chain 70 are connected together with the fixed platform 10.

As shown in Figure 3, the first branch chain 40 and the third branch chain 60 are UPR branch chains; the second branch chain 50 and the fourth branch chain 70 are RRU branch chains; wherein, the first branch chain 40 and the third branch chain 60 are oppositely distributed on the opposite sides of the fixed platform 10 and the moving platform 20 , and the second branch chain 50 and the fourth branch chain 70 are oppositely distributed on the opposite sides of the fixed platform 10 and the moving platform 20 .

As shown in Figure 4, the first branch chain 40 has a first U pair 41, a first moving pair 42 and a first rotating pair 43; one end of the first branch chain 40 is connected with the fixed platform 10 through the first U pair 41, The other end of the first branch chain 40 is connected with the moving platform 20 through the first rotating pair 43; the middle part of the first branch chain 40 forms the first moving pair 42;

As shown in Figure 5, the second branch chain 50 has a second rotating pair 51, a third rotating pair 52 and a second U pair 53; one end of the second branch chain 50 is connected with the fixed platform 10 through the second rotating pair 51, The other end of the second branch chain 50 is connected with the moving platform 20 through the second U pair 53; the middle part of the second branch chain 50 is formed as the third rotating pair 52;

As shown in Figure 6, the third branch chain 60 has the third U pair 61, the second moving pair 62 and the fourth rotation pair 63; one end of the third branch chain 60 is connected with the fixed platform 10 through the third U pair 61, The other end of the third branch chain 60 is connected with the moving platform 20 through the fourth rotating pair 63; the middle part of the third branch chain 60 forms the second moving pair 62;

As shown in Figure 7, the fourth branch chain 70 has the fifth rotating pair 71, the sixth rotating pair 72 and the fourth U pair 73; one end of the fourth branch chain 70 is connected with the fixed platform 10 through the fifth rotating pair 71, The other end of the second branch chain 50 is connected with the moving platform 20 through the fourth U pair 73; the middle part of the fourth branch chain 70 is formed as the sixth rotating pair 72;

As shown in Fig. 3, Fig. 4 and Fig. 6, the first U pair 41 includes a rotation axis $ ₁₁ and a rotation axis $ ₁₂ , and the rotation axis $ ₁₁ and the rotation axis $ ₁₂ intersect perpendicularly; the third U pair 61 includes a rotation axis $ ₃₁ and rotation axis $ ₃₂ ; rotation axis $ ₃₁ and rotation axis $ ₃₂ perpendicularly intersect, rotation axis $ ₁₁ coincides with rotation axis $ ₃₁ , and passes through the central axis of fixed platform 10; rotation axis $ ₁₂ and rotation axis $ ₃₂ are parallel to each other ;

The rotation axis $ ₁₄ and the rotation axis $ ₁₂ of the first rotation pair 43 are parallel to each other; the rotation axis $ ₃₄ and the rotation axis $ ₃₂ of the fourth rotation pair 63 are parallel to each other; the rotation axis $ ₃₄ and the rotation axis $ ₁₄ are parallel to each other;

The moving axis $ ₁₃ of the first moving pair 42 passes through the intersection of the rotating axis $ ₁₁ and the rotating axis $ ₁₂ , and is perpendicular to the rotating axis $ ₁₂ ; the moving axis $ ₃₃ of the second moving pair 62 passes through the turning axis $ ₃₁ and the rotating axis $ ₃₂ , and is perpendicular to the axis of rotation $ ₃₂ .

As shown in Figures 3, 5 and 7, the rotation axis $ ₂₁ of the second rotation pair 51 is parallel to the rotation axis $ ₁₁ and the rotation axis $ ₃₁ ; the rotation axis $ ₂₂ of the third rotation pair 52 is parallel to the rotation axis $ ₂₁ Parallel to each other; the rotation axis $ ₄₁ of the fifth rotation pair 71 is parallel to the rotation axis $ ₁₁ and the rotation axis $ ₃₁ , and the rotation axis $ ₄₂ of the sixth rotation pair 72 is parallel to the rotation axis $ ₄₁ ;

The second U pair 53 includes the rotation axis $ ₂₃ and the rotation axis $ ₂₄ , the rotation axis $ ₂₃ and the rotation axis $ ₂₄ intersect perpendicularly; the fourth U pair 73 includes the rotation axis $ ₄₃ and the rotation axis $ ₄₄ , the rotation axis $ ₄₃ and the rotation axis Axis $ ₄₄ intersects perpendicularly; Rotation axis $ ₂₃ is collinear with rotation axis $ ₄₃ and passes through the central axis of moving platform 20; Rotation axis $ ₂₄ and rotation axis $ ₄₄ are parallel to each other and arranged symmetrically with respect to moving platform 20.

As shown in Figure 3, the first moving pair 42 and the second moving pair 62 in the embodiment of the present invention adopt through-type motor assemblies; as shown in Figure 4, the first moving pair 42 includes a first screw rod 421 and a The first motor 422 that screw mandrel 421 cooperates; The first motor 422 is provided with the first motor fixing frame 423, and the first motor fixing frame 423 and the first U pair 41 carry out rotation cooperation along the axis of rotation $ ₁₂ ; As shown in Figure 6 , the second moving pair 62 includes a second screw mandrel 621 and a second motor 622 that cooperates with the second screw mandrel 621; the second motor 622 is provided with a second motor mount 623, and the second motor mount 623 is connected to the third U The pair 61 is rotationally fitted along the axis of rotation $ ₃₂ .

As shown in Figure 3, in the embodiment of the present invention, the second rotating pair 51 is used as the drive pair for the movement of the second branch chain 50, and the fifth rotating pair 71 is used as the driving pair for the movement of the fourth branch chain 70; as shown in Figure 5, the first The two branch chains 50 include a third motor 54, a first worm 55 and a first worm gear 56; the first worm 55 is arranged on the output end of the third motor 54, the first worm 55 and the first worm gear 56 are matingly connected, and the second rotating pair 51 is driven by the first worm gear 56; specifically, the third motor 54 is fixed on the fixed platform 10, and the first worm gear 56 is preferably rotatably arranged on the fixed platform 10 through the first bracket 57.

As shown in Figure 7, the 4th branch chain 70 comprises the 4th motor 74, the 2nd worm screw 75 and the 2nd worm gear 76; Fittingly connected, the fifth rotating pair 71 is driven by the second worm gear 76; specifically, the fourth motor 74 is fixed on the fixed platform 10, and the second worm gear 76 is preferably rotatably arranged on the fixed platform 10 through the second bracket 77.

Wherein, the first motor 422, the second motor 622, the third motor 54 and the fourth motor 74 are all located on the side of the fixed platform 10 away from the moving platform 20, so that the first motor 422, the second motor 622, the third motor 54 And the rear of the fourth motor 74 does not occupy the space between the moving platform 20 and the fixed platform 10, and on the other hand makes the overall structure more compact.

The UPR branch chain (the first branch chain 40 and the third branch chain 60) in the embodiment of the present invention adopts the mode of screw rod and through-type motor. On the one hand, the first motor 422 and the second motor 622 are both located On one side of the platform 20, the first motor 422 and the second motor 622 are placed behind without occupying the space between the moving platform 20 and the fixed platform 10, and on the other hand, the overall structure is made more compact. Correspondingly, the RRU branch chain also optimizes the arrangement of the third motor 54 and the fourth motor 74, so as to realize the rear placement of the driving motor without occupying the space between the moving platform 20 and the fixed platform 10; The method also has a self-locking function, and the stability and accuracy of the movement are higher.

In the embodiment of the present invention, the moving platform 20 performs a three-degree-of-freedom motion output of two rotations and one movement relative to the fixed platform 10, which meets the needs of performing different types of tasks, as shown in Figure 8; at the same time, it can be replaced according to the type of contact operation. Different types of end tools 30 are used to realize multiple operation functions and expand the scope of application.

Although the present invention is disclosed above with specific embodiments, these specific embodiments are not intended to limit the implementation scope of the present invention. Any person skilled in the art may make some changes/modifications without departing from the scope of the present invention, that is, all equivalent changes/modifications made according to the present invention shall be covered by the protection scope of the present invention.

Claims (6)

1. A three-degree-of-freedom redundant parallel-connection end force control actuator based on a 2UPR-2RRU mechanism comprises a fixed platform, a movable platform, an end tool, a first branched chain, a second branched chain, a third branched chain and a fourth branched chain; the end tool is arranged on the movable platform; the movable platform is connected with the fixed platform through the first branched chain, the second branched chain, the third branched chain and the fourth branched chain;

the first branched chain and the third branched chain are UPR branched chains; the second branch chain and the fourth branch chain are RRU branch chains;

the first branch chain is provided with a first U pair, a first moving pair and a first rotating pair; one end of the first branched chain is connected with the fixed platform through the first U pair, and the other end of the first branched chain is connected with the movable platform through the first rotating pair; the middle part of the first branched chain forms the first sliding pair;

the second branched chain is provided with a second revolute pair, a third revolute pair and a second U pair; one end of the second branched chain is connected with the fixed platform through the second revolute pair, and the other end of the second branched chain is connected with the movable platform through the second U pair; the middle part of the second branched chain is formed into the third revolute pair;

the third branched chain is provided with a third U pair, a second sliding pair and a fourth rotating pair; one end of the third branched chain is connected with the fixed platform through the third U pair, and the other end of the third branched chain is connected with the movable platform through the fourth revolute pair; the middle part of the third branched chain forms the second sliding pair;

the fourth branched chain is provided with a fifth revolute pair, a sixth revolute pair and a fourth U pair; one end of the fourth branched chain is connected with the fixed platform through the fifth revolute pair, and the other end of the second branched chain is connected with the movable platform through the fourth U pair; the middle part of the fourth branched chain is formed into the sixth revolute pair;

the first U pair comprises a rotation axis $ ₁₁ And axis of rotation $ ₁₂ Rotation axis $ ₁₁ And axis of rotation $ ₁₂ Vertically intersecting; the third U pair comprises a rotation axis $ ₃₁ And axis of rotation $ ₃₂ (ii) a Axis of rotation $ ₃₁ And axis of rotation $ ₃₂ Perpendicular to the axis of rotation $ ₁₁ And axis of rotation $ ₃₁ Overlapping; rotation axis $ ₁₂ And axis of rotation $ ₃₂ Are parallel to each other;

the rotation axis of the first rotating pair $ ₁₄ And axis of rotation $ ₁₂ Are parallel to each other; the rotation axis of the fourth revolute pair $ ₃₄ And axis of rotation $ ₃₂ Are parallel to each other; axis of rotation $ ₃₄ And axis of rotation $ ₁₄ Are parallel to each other;

the moving axis of the first moving pair $ ₁₃ Through the axis of rotation $ ₁₁ And axis of rotation $ ₁₂ And the intersection point of (c) with the axis of rotation $ ₁₂ Vertically; the second sliding pair moving axis $ ₃₃ Through the axis of rotation $ ₃₁ And axis of rotation $ ₃₂ And the intersection point of (c) with the axis of rotation $ ₃₂ Vertically;

the rotation axis of the second revolute pair $ ₂₁ To the axis of rotation $ ₁₁ Axis of rotation $ ₃₁ Are parallel to each other; the rotation axis of the third revolute pair $ ₂₂ To the axis of rotation $ ₂₁ Are parallel to each other; the rotation axis of the fifth revolute pair $ ₄₁ To the axis of rotation $ ₁₁ Axis of rotation $ ₃₁ Parallel to each other, the rotation axis $ofthe sixth revolute pair ₄₂ To the axis of rotation $ ₄₁ Are parallel to each other;

the second U pair comprises a rotation axis $ ₂₃ And axis of rotation $ ₂₄ Axis of rotation $ ₂₃ And axis of rotation $ ₂₄ Vertically intersecting; the fourth U pair comprises a rotation axis $ ₄₃ And axis of rotation $ ₄₄ Axis of rotation $ ₄₃ And axis of rotation $ ₄₄ Vertically intersecting; rotation axis $ ₂₃ To the axis of rotation $ ₄₃ Collinear; rotation axis $ ₂₄ And axis of rotation $ ₄₄ Are parallel to each other and are symmetrically arranged relative to the movable platform.

2. The three-degree-of-freedom redundant parallel end force-controlled actuator based on a 2UPR-2RRU mechanism of claim 1, wherein: rotation axis $ ₁₁ And axis of rotation $ ₃₁ A central axis passing through the stationary platform; axis of rotation $ ₂₃ To the axis of rotation $ ₄₃ The central axis passes through the movable platform.

3. The three-degree-of-freedom redundant parallel end force-controlled actuator based on a 2UPR-2RRU mechanism of claim 1, wherein: the first moving pair and the second moving pair adopt penetrating motor components;

the first sliding pair comprises a first screw rod and a first motor matched with the first screw rod; the first motor is provided with a first motor fixing frame, and the first motor fixing frame and the first U pair rotate along a rotating axis $ ₁₂ Performing rotary matching;

the second sliding pair comprises a second screw rod and a second motor matched with the second screw rod; a second motor fixing frame is arranged on the second motor, and the second motor fixing frame and the third U pair rotate along the rotation axis $ ₃₂ And performing rotating fit.

4. The three-degree-of-freedom redundant parallel end force-controlled actuator based on a 2UPR-2RRU mechanism of claim 3, wherein: the first motor and the second motor are both located on one side, far away from the movable platform, of the fixed platform.

5. The three-degree-of-freedom redundant parallel end force-controlled actuator based on a 2UPR-2RRU mechanism of claim 1, wherein: the second rotating pair is used as a driving pair for the second branched chain to move, and the fifth rotating pair is used as a driving pair for the fourth branched chain to move;

the second branched chain comprises a third motor, a first worm and a first worm wheel; the first worm is arranged at the output end of the third motor, the first worm is in fit connection with the first worm wheel, and the second revolute pair is driven by the first worm wheel;

the fourth branch chain comprises a fourth motor, a second worm and a second worm wheel; the second worm is arranged at the output end of the fourth motor, the second worm is connected with the second worm wheel in a matching mode, and the fifth revolute pair is driven by the second worm wheel.

6. The three-degree-of-freedom redundant parallel end force-controlled actuator based on a 2UPR-2RRU mechanism of claim 5, wherein: the third motor and the fourth motor are both positioned on one side, away from the movable platform, of the fixed platform.

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