A 3D rotational and 2D translational parallel robot

Abstract

The present invention relates to the technical field of parallel robots, and discloses a three-dimensional rotating and two-dimensional moving parallel robot, comprising a fixed platform, a moving platform, a driving branch I, a driving branch II, a driving branch III, a driving branch IV, a driving branch V and a driving branch VI, wherein the fixed platform and the moving platform are connected through five RUS-type driving branches I, II, III, IV and V with completely the same structure and an SPR-type constraint branch VI, wherein the driving branch VI comprises a second rotating pair, a second upper connecting rod, a second lower connecting rod and a second ball pair, wherein the moving platform is connected to the second upper connecting rod through the second rotating pair, and the second upper connecting rod is connected to the second lower connecting rod through a moving pair; in the present invention, the parallel robot can realize three-dimensional rotation and two-dimensional movement, and relative to a traditional five-DOF parallel robot, the robot has the advantages of simple structure, large working space and easy control.

Description

Technical Field

[0001] The present invention relates to the technical field of parallel robots, and particularly to a three-dimensional rotational and two-dimensional translational parallel robot. Background Art

[0002] A parallel robot, whose English name is Parallel Mechanism and is abbreviated as PM, can be defined as a closed-loop mechanism in which a moving platform and a fixed platform are connected by at least two independent kinematic chains, the mechanism has two or more degrees of freedom, and is driven in a parallel manner. The parallel robot mechanism has become a research hotspot in the fields of mechanism theory and robotics in the past two decades. The characteristics of a parallel robot are presented as no cumulative error, high precision, and the driving device can be placed on the fixed platform or at a position close to the fixed platform.

[0003] There are various parallel robots on the market. However, the structures used in parallel robots are complex, and it is not easy to manipulate them flexibly during the working process. There is a need to improve a three-dimensional rotational and two-dimensional translational parallel robot. Summary of the Invention

[0004] (1) Technical Problems to be Solved

[0005] Aiming at the deficiencies of the prior art, the present invention provides a three-dimensional rotational and two-dimensional translational parallel robot, which solves the problems raised in the above background art.

[0006] (2) Technical Solutions

[0007] To achieve the above object, the present invention provides the following technical solution: A three-dimensional rotational and two-dimensional translational parallel robot includes a fixed platform, a moving platform, driving branch Ⅰ, driving branch Ⅱ, driving branch Ⅲ, driving branch Ⅳ, driving branch Ⅴ, and constraint branch Ⅵ. The fixed platform and the moving platform are connected by five driving branches Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ of the same RUS type and one SPR type constraint branch Ⅵ. The driving branch Ⅰ, the driving branch Ⅱ, the driving branch Ⅲ, the driving branch Ⅳ, and the driving branch Ⅴ respectively include a first revolute pair, a first lower connecting rod, a Hooke's joint, a first upper connecting rod, and a first spherical pair. The fixed platform is connected to the first lower connecting rod through the first revolute pair, the first lower connecting rod is connected to the first upper connecting rod through the Hooke's joint, and the first upper connecting rod is connected to the moving platform through the first spherical pair. The five first revolute pairs connected to the fixed platform serve as the driving devices for each branch. The constraint branch Ⅵ includes a second revolute pair, a second upper connecting rod, a second lower connecting rod, and a second spherical pair. The moving platform is connected to the second upper connecting rod through the second revolute pair, the second upper connecting rod is connected to the second lower connecting rod through a prismatic pair, and the second lower connecting rod is connected to the fixed platform through the second spherical pair.

[0008] Preferably, the rotation direction of the first revolute pair is the same as that of the revolute pair where the Hooke joint is fixed on the first lower connecting rod.

[0009] Preferably, the five first spherical pairs connected to the moving platform are evenly distributed on the same circumference centered at the center of the lower surface of the moving platform.

[0010] Preferably, the five first revolute pairs connected to the fixed platform are evenly distributed on the same circumference centered at the center of the upper surface of the fixed platform.

[0011] Preferably, the second revolute pair on the constraint branch VI is arranged at the center of the lower surface of the moving platform, and the second spherical pair on the constraint branch VI is arranged at the center of the upper surface of the fixed platform.

[0012] (III) Advantageous Effects

[0013] The present invention provides a 3D rotational and 2D translational parallel robot, having the following advantageous effects:

[0014] (1) In the present invention, the parallel robot can achieve 3D rotation and 2D translation. Compared with the traditional five-degree-of-freedom parallel robot, this robot has the advantages of simple structure, large working space, and easy control. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of Embodiment 1 provided by the present invention;

[0016] Figure 2 is a specific structural diagram of Embodiment 1 provided by the present invention;

[0017] Figure 3 is a schematic structural diagram of Embodiment 2 provided by the present invention;

[0018] Figure 4 is a specific structural diagram of Embodiment 2 provided by the present invention.

[0019] Figure 1-2 In the figures: 1, fixed platform; 2, first revolute pair; 3, first lower connecting rod; 4, Hooke joint; 5, first upper connecting rod; 6, first spherical pair; 7, moving platform; 8, second revolute pair; 9, second upper connecting rod; 10, second lower connecting rod; 11, second spherical pair. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Embodiment 1

[0022] As Figure 1-2 shown, the present invention provides a technical solution: a three-dimensional rotating and two-dimensional moving parallel robot, including a fixed platform 1, a moving platform 7, a driving branch I, a driving branch II, a driving branch III, a driving branch IV, a driving branch V, and a constraint branch VI. The fixed platform 1 and the moving platform 7 are connected by five driving branches I, II, III, IV, V of the same structure of the RUS type and a constraint branch VI of the SPR type. The driving branches I, II, III, IV, and V respectively include a first rotating pair 2, a first lower connecting rod 3, a Hooke's joint 4, a first upper connecting rod 5, and a first spherical pair 6. The fixed platform 1 is connected to the first lower connecting rod 3 through the first rotating pair 2. The first lower connecting rod 3 is connected to the first upper connecting rod 5 through the Hooke's joint 4. The first upper connecting rod 5 is connected to the moving platform 7 through the first spherical pair 6. The five first rotating pairs 2 connected to the fixed platform 1 serve as the driving devices for each branch. The first rotating pair 2 is connected to an external motor. The constraint branch VI includes a second rotating pair 8, a second upper connecting rod 9, a second lower connecting rod 10, and a second spherical pair 11. The moving platform 7 is connected to the second upper connecting rod 9 through the second rotating pair 8. The second upper connecting rod 9 is connected to the second lower connecting rod 10 through a moving pair. The second lower connecting rod 10 is connected to the fixed platform 1 through the second spherical pair 11. The improved parallel robot has a simple structure, is easy to control during operation, and has stable support.

[0023] Furthermore, the rotation direction of the first rotating pair 2 is the same as the rotation direction of the rotating pair where the Hooke's joint 4 is fixed on the first lower connecting rod 3. The same rotation direction of the two is convenient for controlling the vertical or inclined rotation of the first upper connecting rod 5 and the first lower connecting rod 3.

[0024] Furthermore, the five first spherical pairs 6 connected to the moving platform 7 are evenly distributed on the same circumference with the center of the lower surface of the moving platform 7 as the center of the circle. The first spherical pairs 6 are embedded inside the moving platform 7. During the operation of the parallel robot, the first spherical pairs 6 roll in the moving platform 7. The even distribution of the five first spherical pairs 6 can stably support the moving platform 7.

[0025] Furthermore, the five first rotating pairs 2 connected to the fixed platform 1 are evenly distributed on the same circumference with the center of the upper surface of the fixed platform 1 as the center of the circle. The multiple first rotating pairs 2 are evenly distributed on the fixed platform 1. The driving branches between the fixed platform 1 and the moving platform 7 can be evenly distributed, and the parallel robot has strong supporting force.

[0026] Further, the second revolute pair 8 on the constraint branch VI is provided at the center of the lower surface of the moving platform 7, and the second spherical pair 11 on the constraint branch VI is provided at the center of the upper surface of the fixed platform 1. The constraint branch VI connects the middle positions of the moving platform 7 and the fixed platform 1, so that the phenomenon of unstable support of the moving platform 7 can be avoided.

[0027] Embodiment 2

[0028] As Figure 3-4 shown, the present invention provides a technical solution: a three-dimensional rotation and two-dimensional translation parallel robot, including a fixed platform 1, a moving platform 7, a driving branch I, a driving branch II, a driving branch III, a driving branch IV, a driving branch V, and a constraint branch VI. The fixed platform 1 and the moving platform 7 are connected by five driving branches I, II, III, IV, V of the completely same RUS type and a SRR type constraint branch VI. The driving branches I, II, III, IV, and V respectively include a first revolute pair 2, a first lower connecting rod 3, a Hooke's joint 4, a first upper connecting rod 5, and a first spherical pair 6. The fixed platform 1 is connected to the first lower connecting rod 3 through the first revolute pair 2. The first lower connecting rod 3 is connected to the first upper connecting rod 5 through the Hooke's joint 4. The first upper connecting rod 5 is connected to the moving platform 7 through the first spherical pair 6. The five first revolute pairs 2 connected to the fixed platform 1 serve as the driving devices for each branch, and the first revolute pair 2 is connected to an external motor. The constraint branch VI includes a second revolute pair 8, a second upper connecting rod 9, a third revolute pair 10, a second lower connecting rod 11, and a second spherical pair 12. The moving platform 7 is connected to the second upper connecting rod 9 through the second revolute pair 8. The second upper connecting rod 9 is connected to the second lower connecting rod 11 through the third revolute pair 10. The second lower connecting rod 11 is connected to the fixed platform 1 through the second spherical pair 12. The parallel robot can achieve three-dimensional rotation and two-dimensional translation. Compared with the traditional five-degree-of-freedom parallel robot, this robot has the advantages of simple structure, large working space, and easy control.

[0029] Further, the five first spherical pairs 6 connected to the moving platform 7 are evenly distributed on the same circumference with the center of the lower surface of the moving platform 7 as the center of the circle. The five first spherical pairs 6 are connected together to form a circular ring. The uniform distribution of the multiple first spherical pairs 6 is beneficial to the subsequent driving branches to support the moving platform 7.

[0030] Further, the five first revolute pairs 2 connected to the fixed platform 1 are evenly distributed on the same circumference with the center of the upper surface of the fixed platform 1 as the center of the circle. The five first revolute pairs 2 are connected together to form a circular ring.

[0031] Further, the second revolute pair 8 on the constraint branch VI is provided at the center of the lower surface of the moving platform 7, and the second spherical pair 12 on the constraint branch VI is provided at the center of the upper surface of the fixed platform 1. The constraint branch VI supports the middle part of the moving platform 7.

[0032] Further, the rotation direction of the first rotating pair 2 is the same as the rotation direction of the rotating pair where the Hooke joint 4 is fixed to the first lower connecting rod 3. The same rotation direction facilitates the manipulation of the tilt angle of the first upper connecting rod 5 or the first lower connecting rod 3 to rotate.

[0033] Further, the rotation direction of the second rotating pair 8 is the same as the rotation direction of the third rotating pair 10.

[0034] In summary, the working process of the present invention is as follows: When in use, by driving branches Ⅰ, Ⅱ, Ⅲ, Ⅳ, and Ⅴ, the platform above the driving branches can be driven to achieve three-dimensional rotation and two-dimensional movement. Compared with traditional five-degree-of-freedom parallel robots, this robot has the advantages of simple structure, stable support, and easy control.

[0035] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0036] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A three-dimensional rotational and two-dimensional translational parallel robot, comprising a fixed platform, a moving platform, driving branch Ⅰ, driving branch Ⅱ, driving branch Ⅲ, driving branch Ⅳ, driving branch Ⅴ and constraint branch Ⅵ. It is characterized in that: The fixed platform and the moving platform are connected by five driving branches Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ of the completely identical RUS type and a constraint branch Ⅵ of the SPR type. The driving branch Ⅰ, the driving branch Ⅱ, the driving branch Ⅲ, the driving branch Ⅳ and the driving branch Ⅴ respectively include a first revolute pair, a first lower connecting rod, a Hooke's joint, a first upper connecting rod and a first spherical pair. The fixed platform is connected to the first lower connecting rod through the first revolute pair. The first lower connecting rod is connected to the first upper connecting rod through the Hooke's joint. The first upper connecting rod is connected to the moving platform through the first spherical pair. The five first revolute pairs connected to the fixed platform serve as the driving devices for each branch. The constraint branch Ⅵ includes a second revolute pair, a second upper connecting rod, a second lower connecting rod and a second spherical pair. The moving platform is connected to the second upper connecting rod through the second revolute pair. The second upper connecting rod is connected to the second lower connecting rod through a prismatic pair. The second lower connecting rod is connected to the fixed platform through the second spherical pair. The second revolute pair on the constraint branch Ⅵ is arranged at the center of the lower surface of the moving platform. The second spherical pair on the constraint branch Ⅵ is arranged at the center of the upper surface of the fixed platform. The rotation direction of the first revolute pair is the same as the rotation direction of the revolute pair where the Hooke's joint is fixed on the first lower connecting rod.

2. The three-dimensional rotational and two-dimensional translational parallel robot according to claim 1, It is characterized in that: The five first spherical pairs connected to the moving platform are evenly distributed on the same circumference with the center of the lower surface of the moving platform as the center of the circle.

3. The three-dimensional rotational and two-dimensional translational parallel robot according to claim 1, It is characterized in that: The five first revolute pairs connected to the fixed platform are evenly distributed on the same circumference with the center of the upper surface of the fixed platform as the center of the circle.

Images