Non-coupling parallel robot

Abstract

The invention provides a non-coupling parallel robot. The non-coupling parallel robot comprises a fixed platform, a movable platform, three driving branch chains and a just constraint branch chain. The three driving branch chains move on the fixed platform in the mode that every two driving branch chains are perpendicular to each other, one ends of the driving branch chains are connected with the fixed platform through moving pairs, and the other ends of the driving branch chains are connected with the movable platform through rotating pairs. The first driving branch chain and the third driving branch chain have the same structural form, and each of the first driving branch chain and the third driving branch chain consists of two moving pairs and three rotating pairs; the second driving branch chain is composed of two moving pairs and two rotating pairs. The right constraint branch chain is composed of a moving pair and a cylindrical pair, and the direction of the moving pair is perpendicular to the axis and the moving direction of the cylindrical pair. The four branches perform their own functions, complete decoupling of spatial three degrees of freedom is achieved, kinematics and dynamics modeling is easy, and the three-degree-of-freedom decoupling mechanism has the advantages of being simple in structure, easy to control and the like; meanwhile, the rigidity and the bearing capacity of the mechanism are improved and the stress condition of the mechanism is improved through the design of the just constraint branch chains.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial robots, and in particular relates to a non-coupling parallel robot. Background Art

[0002] The parallel mechanism is usually composed of a moving platform and a fixed platform connected by multiple branches. Compared with the series structure, it has the advantages of compact structure, easy control and small cumulative error. Among them, the design of the just-constrained structure improves the stiffness and load-bearing capacity of the mechanism and improves the stress condition of the mechanism. It has been widely used in many fields such as medical equipment, parallel machine tools, aerospace, etc. However, the parallel mechanism has strong coupling and complex solutions to kinematics and dynamics problems. Summary of the invention

[0003] The purpose of the present invention is to provide a non-coupled parallel robot to solve the difficulties in analysis and calculation, configuration design and mechanism control caused by the strong coupling of the parallel mechanism existing in the prior art, while ensuring the rigidity, stability and load-bearing capacity of the mechanism.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: a non-coupled parallel robot, including a fixed platform, a moving platform and a plurality of kinematic chains, the plurality of kinematic chains including a first active branch chain, a second active branch chain, a third active branch chain and a just-constrained branch chain; The first active branch chain comprises a first moving pair, a first rotating pair, a second moving pair, a second rotating pair and a third rotating pair which are sequentially connected by connecting rods, the first moving pair and the third rotating pair are respectively connected to the fixed platform and the moving platform, and the moving direction of the first moving pair is parallel to the rotating axes of the first rotating pair and the second rotating pair, and is perpendicular to the moving direction of the second moving pair and the rotating axis of the third rotating pair; The second active branch chain comprises a third moving pair, a fourth rotating pair, a fourth moving pair and a fifth rotating pair connected in sequence by connecting rods, the third moving pair and the fifth rotating pair are respectively connected to the fixed platform and the moving platform, and the moving direction of the third moving pair is respectively parallel to the rotating axes of the fourth rotating pair and the fifth rotating pair, and is perpendicular to the moving direction of the fourth moving pair; The third active branch chain comprises a fifth moving pair, a sixth rotating pair, a sixth moving pair, a seventh rotating pair and an eighth rotating pair which are sequentially connected by connecting rods, the fifth moving pair and the eighth rotating pair are respectively connected to the fixed platform and the moving platform, and the moving direction of the fifth moving pair is parallel to the rotating axes of the sixth rotating pair and the seventh rotating pair, respectively, and is perpendicular to the moving direction of the sixth moving pair and the rotating axis of the eighth rotating pair; The just-constrained branch chain includes a seventh moving pair and a cylindrical pair connected by a connecting rod, and the seventh moving pair and the cylindrical pair are respectively connected to the fixed platform and the moving platform, and the moving direction of the seventh moving pair is perpendicular to the axis of the cylindrical pair; The moving directions of the first moving pair, the third moving pair and the fifth moving pair are perpendicular to each other, and the moving direction of the seventh moving pair is parallel to the moving direction of the first moving pair; The rotation axis of the third rotation pair, the rotation axis of the fifth rotation pair, the rotation axis of the eighth rotation pair and the axis of the cylindrical pair are distributed on the same plane and are arranged in parallel; and the third rotation pair, the cylindrical pair and the fifth rotation pair are distributed on the same straight line; Specifically, the first moving pair, the third moving pair and the fifth moving pair are all active pairs of the kinematic chains in which they are located.

[0005] Specifically, the driving mechanism of the active pair is a servo motor.

[0006] Specifically, the moving platform is a rectangular platform.

[0007] Specifically, the third rotation pair, the fifth rotation pair and the cylindrical pair are all connected to the same side of the moving platform, and the eighth rotation pair is connected to the other side of the moving platform opposite to the side.

[0008] Specifically, the connecting rods in the first active branch chain include a first connecting rod, a second connecting rod, a third connecting rod and a fourth connecting rod, one end of the first connecting rod is connected to the first movable pair, the other end of the first connecting rod is connected to the first rotating pair, the second connecting rod and the third connecting rod are slidably connected to form the second movable pair, the second connecting rod is connected to the first rotating pair, the third connecting rod is connected to the second rotating pair, and the two ends of the fourth connecting rod are respectively connected to the second rotating pair and the third rotating pair.

[0009] Specifically, the connecting rods in the second active branch chain include a fifth connecting rod, a sixth connecting rod and a seventh connecting rod, one end of the fifth connecting rod is connected to the third movable pair, the other end of the fifth connecting rod is connected to the fourth rotating pair, the sixth connecting rod and the seventh connecting rod are slidably connected to form the fourth movable pair, the sixth connecting rod is also connected to the fourth rotating pair, and the seventh connecting rod is also connected to the fifth rotating pair.

[0010] Specifically, the connecting rods in the third active branch chain include an eighth connecting rod, a ninth connecting rod, a tenth connecting rod and an eleventh connecting rod, one end of the eighth connecting rod is connected to the fifth movable pair, the other end of the eighth connecting rod is connected to the sixth rotating pair, the ninth connecting rod and the tenth connecting rod are slidingly connected to form the sixth movable pair, the ninth connecting rod is also connected to the sixth rotating pair, the tenth connecting rod is also connected to the seventh rotating pair, and the two ends of the eleventh connecting rod are respectively connected to the seventh rotating pair and the eighth rotating pair.

[0011] The beneficial effects of the present invention are as follows: in the present invention, when the first moving pair in the first active branch chain is inputted separately as an active pair, the moving platform has one degree of freedom of movement; when the third moving pair in the second active branch chain is inputted separately as an active pair, the moving platform has another degree of freedom of movement; when the fifth moving pair of the third active branch chain is inputted separately as an active pair, the moving platform has one degree of freedom of rotation; thus, the present invention has three degrees of freedom, namely, rotation in one direction and movement in two directions. At this time, the velocity Jacobian matrix of the mechanism is a diagonal matrix, which has completely decoupled kinematic characteristics, and is simple to control and highly practical. It solves the problems of strong coupling of ordinary parallel mechanisms, complex kinematic calculations, and difficult path planning, and has broad application prospects. Moreover, the design of the just-constrained branch chain improves the stiffness and load-bearing capacity of the mechanism and improves the stress condition of the mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 This is a schematic diagram of the overall structure of the uncoupled parallel robot of the present invention; Reference numerals: 100, fixed platform, 200, movable platform; 1-1, first connecting rod, 1-2, second connecting rod, 1-3, third connecting rod, 1-4, fourth connecting rod, 2-1, fifth connecting rod, 2-2, sixth connecting rod, 2-3, seventh connecting rod, 3-1, eighth connecting rod, 3-2, ninth connecting rod, 3-3, tenth connecting rod, 3-4, eleventh connecting rod, 4-1, twelfth connecting rod; L1, first active branch chain, L2, second active branch chain, L3, third active branch chain, L4, just-constrained branch chain; P11, first moving pair, R12, first rotating pair, P13, second moving pair, R14, second rotating pair, R15, third rotating pair; P21, the third moving pair, R22, the fourth rotating pair, P23, the fourth moving pair, R24, the fifth rotating pair; P31, the fifth moving pair, R32, the sixth rotating pair, P33, the sixth moving pair, R34, the seventh rotating pair, R35, the eighth rotating pair; P41, seventh movable pair, C42, cylindrical pair. DETAILED DESCRIPTION

[0014] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the invention in any way.

[0015] like Figure 1 As shown, a non-coupled parallel robot includes a fixed platform 100, a moving platform 200, and a first active branch chain L1, a second active branch chain L2, a third active branch chain L3 and a just-constrained branch chain L4 arranged between the fixed platform 100 and the moving platform 200.

[0016] The first active branch chain L1 is a PRPRR type active branch chain, including a first moving pair P11, a first rotating pair R12, a second moving pair P13, a second rotating pair R14 and a third rotating pair R15 connected in sequence from the fixed platform 100 to the moving platform 200. The first moving pair P11 and the third rotating pair R15 are directly connected to the fixed platform 100 and the moving platform 200 respectively, one side of the first rotating pair R12 is connected to the first moving pair P11 through the first connecting rod 1-1, the other side of the first rotating pair R12 is connected to one side of the second rotating pair R14 through the second moving pair P13, the other side of the second rotating pair R14 is connected to the third rotating pair R15 through the fourth connecting rod 1-4, the second moving pair P13 is composed of a second connecting rod 1-2 and a third connecting rod 1-3 connected in sliding relation, the second connecting rod 1-2 is connected to the first rotating pair R12, and the third connecting rod 1-3 is connected to the second rotating pair R14. Furthermore, the moving direction of the first moving pair P11 is parallel to the rotation axis of the first rotation pair R12 and the rotation axis of the second rotation pair R14, and is perpendicular to the moving direction of the second moving pair P13 and the rotation axis of the third rotation pair R15.

[0017] The second active branch chain L2 is a PRPR type active branch chain, including a third mobile pair P21, a fourth rotation pair R22, a fourth mobile pair P23 and a fifth rotation pair R24 ​​connected in sequence from the fixed platform 100 to the moving platform 200. The third mobile pair P21 and the fifth rotation pair R24 ​​are directly connected to the fixed platform 100 and the moving platform 200 respectively, one side of the fourth rotation pair R22 is connected to the third mobile pair P21 through the fifth connecting rod 2-1, and the other side of the fourth rotation pair R22 is connected to the fifth rotation pair R24 ​​through the fourth mobile pair P23. The fourth mobile pair P23 is composed of a sixth connecting rod 2-2 and a seventh connecting rod 2-3 that slide against each other, the sixth connecting rod 2-2 is connected to the fourth rotation pair R22, and the seventh connecting rod 2-3 is connected to the fifth rotation pair R24. Furthermore, the moving direction of the third movable pair P21 is parallel to the rotation axis of the fourth rotation pair R22 and the rotation axis of the fifth rotation pair R24, and is perpendicular to the moving direction of the fourth movable pair P23.

[0018] The third active branch chain L3 is a PRPRR type active branch chain, including a fifth moving pair P31, a sixth rotating pair R32, a sixth moving pair P33, a seventh rotating pair R34 and an eighth rotating pair R35 connected in sequence from the fixed platform 100 to the moving platform 200. The fifth moving pair P31 and the eighth rotating pair R35 are directly connected to the fixed platform 100 and the moving platform 200 respectively, one side of the sixth rotating pair R32 is connected to the fifth moving pair P31 through the eighth connecting rod 3-1, the other side of the sixth rotating pair R32 is connected to one side of the seventh rotating pair R34 through the sixth moving pair P33, the other side of the seventh rotating pair R34 is connected to the eighth rotating pair R35 through the eleventh connecting rod 3-4, the sixth moving pair P33 is composed of a ninth connecting rod 3-2 and a tenth connecting rod 3-3 connected in sliding connection, the ninth connecting rod 3-2 is connected to the sixth rotating pair R32, and the tenth connecting rod 3-3 is connected to the seventh rotating pair R34. Furthermore, the moving direction of the fifth movable pair P31 is parallel to the rotation axis of the sixth rotation pair R32 and the rotation axis of the seventh rotation pair R34, and is perpendicular to the moving direction of the sixth movable pair P33 and the rotation axis of the eighth rotation pair R35.

[0019] The just-constrained branch chain L4 includes a seventh mobile pair P41 and a cylindrical pair C42. One end of the seventh mobile pair P41 and one end of the cylindrical pair are directly connected to the fixed platform 100 and the moving platform 200 respectively, and the seventh mobile pair P41 is connected to the cylindrical pair C42 through the twelfth connecting rod 4-1. The moving direction of the seventh mobile pair P41 is perpendicular to the rotation axis of the cylindrical pair C42.

[0020] As an option, the first moving pair P11, the third moving pair P21, the fifth moving pair P31 and the seventh moving pair P41 are slider assemblies, including slidably matched linear rails and sliders, and the corresponding connecting rods are fixedly connected to the sliders.

[0021] In this embodiment, the moving direction of the first moving pair P11 in the first active branch chain L1, the moving direction of the third moving pair P21 in the second active branch chain L2, and the moving direction of the fifth moving pair P31 in the third active branch chain L3 are perpendicular to each other, and the moving direction of the seventh moving pair P41 in the branch chain L4 is just constrained to be parallel to the moving direction of the first moving pair P11 in the first active branch chain L1.

[0022] Further, the rotation axis of the third rotation pair R15 in the first active branch chain L1, the rotation axis of the fifth rotation pair R24 ​​in the second active branch chain L2, the rotation axis of the eighth rotation pair R35 in the third active branch chain L3, and the axis of the cylindrical pair C42 in the just-constrained branch chain L4 are distributed on the same plane and are arranged in parallel. Specifically, the plane of the moving platform is a rectangle, the third rotation pair R15 in the first active branch chain L1, the fifth rotation pair R24 ​​in the second active branch chain L2, and the cylindrical pair C42 in the just-constrained branch chain L4 are all connected to the same side of the moving platform 200, the eighth rotation pair R35 in the third active branch chain L3 is connected to the other side of the moving platform 200 opposite to the side, and the third rotation pair R15 in the first active branch chain L1, the cylindrical pair C42 in the just-constrained branch chain L4, and the fifth rotation pair R24 ​​in the second active branch chain L2 are sequentially arranged along the length direction of one side of the moving platform P2 and the three are distributed on the same straight line.

[0023] In the parallel mechanism, the first moving pair P11 in the first active branch chain L1, the third moving pair P21 in the second active branch chain L2, and the fifth moving pair P31 in the third active branch chain L3 are all active pairs of corresponding kinematic chains and are driven by corresponding servo motors.

[0024] The control principle of the present invention is as follows: the present invention drives the active pair through the servo motor, and provides power to the moving platform 200 through three active branches. The first driving motor drives the first moving pair P11 in the first active branch chain L1, so that the moving platform 200 moves along the moving direction of the first moving pair P11 in the first active branch chain L1; the second driving motor drives the third moving pair P21 in the second active branch chain L2, so that the moving platform 200 moves along the moving direction of the third moving pair P21 in the second active branch chain L2; the third driving motor drives the fifth moving pair P31 in the third active branch chain L3, so that the moving platform 200 rotates around the rotation axis of the cylindrical pair C42 in the just constrained branch chain L4, thereby realizing the three-degree-of-freedom movement of the parallel mechanism in space with one rotation and two movements.

[0025] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Those skilled in the art should understand that the specific implementation modes of the present invention may be modified or replaced by equivalents with reference to the above embodiments. Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention are within the scope of protection of the pending claims.

Claims

1. An uncoupled parallel robot, comprising a fixed platform (100), a moving platform (200) and a plurality of kinematic chains, characterized in that: The plurality of kinematic chains include a first active branch chain (L1), a second active branch chain (L2), a third active branch chain (L3) and a just-constrained branch chain (L4); The first active branch chain (L1) comprises a first moving pair (P11), a first rotating pair (R12), a second moving pair (P13), a second rotating pair (R14) and a third rotating pair (R15) which are sequentially connected via connecting rods; the first moving pair (P11) and the third rotating pair (R15) are respectively connected to the fixed platform (100) and the moving platform (200); the moving direction of the first moving pair (P11) is respectively parallel to the rotating axes of the first rotating pair (R12) and the second rotating pair (R14), and is perpendicular to the moving direction of the second moving pair (P13) and the rotating axis of the third rotating pair (R15); The second active branch chain (L2) comprises a third movable pair (P21), a fourth rotation pair (R22), a fourth movable pair (P23) and a fifth rotation pair (R24) which are connected in sequence through connecting rods, the third movable pair (P21) and the fifth rotation pair (R24) are respectively connected to the fixed platform (100) and the movable platform (200), and the moving direction of the third movable pair (P21) is respectively parallel to the rotation axes of the fourth rotation pair (R22) and the fifth rotation pair (R24), and is perpendicular to the moving direction of the fourth movable pair (P23); The third active branch chain (L3) comprises a fifth moving pair (P31), a sixth rotating pair (R32), a sixth moving pair (P33), a seventh rotating pair (R34) and an eighth rotating pair (R35) which are sequentially connected by connecting rods, the fifth moving pair (P31) and the eighth rotating pair (R35) are respectively connected to the fixed platform (100) and the moving platform (200), and the moving direction of the fifth moving pair (P31) is parallel to the rotation axes of the sixth rotating pair (R32) and the seventh rotating pair (R34), and is perpendicular to the moving direction of the sixth moving pair (P33) and the rotation axis of the eighth rotating pair (R35); The just-constrained branch chain (L4) comprises a seventh mobile pair (P41) and a cylindrical pair (C42) connected by a connecting rod, and the seventh mobile pair (P41) and the cylindrical pair (C42) are respectively connected to the fixed platform (100) and the movable platform (200), and the moving direction of the seventh mobile pair (P41) is perpendicular to the axis of the cylindrical pair (C42); The moving direction of the first moving pair (P11), the moving direction of the third moving pair (P21) and the moving direction of the fifth moving pair (P31) are perpendicular to each other, and the moving direction of the seventh moving pair (P41) is parallel to the moving direction of the first moving pair (P11).

2. The uncoupled parallel robot according to claim 1, characterized in that: The rotation axis of the third rotation pair (R15), the rotation axis of the fifth rotation pair (R24), the rotation axis of the eighth rotation pair (R35) and the axis of the cylindrical pair (C42) are distributed on the same plane and are arranged in parallel; and the third rotation pair (R15), the cylindrical pair (C42) and the fifth rotation pair (R24) are distributed on the same straight line.

3. The uncoupled parallel robot according to claim 1, characterized in that: The first moving pair (P11), the third moving pair (P21) and the fifth moving pair (P31) are all active pairs in the kinematic chains in which they are located.

4. The uncoupled parallel robot according to claim 3, characterized in that: The driving mechanism of the active pair is a servo motor.

5. The uncoupled parallel robot according to claim 1, characterized in that: The moving platform (200) is a rectangular platform.

6. The uncoupled parallel robot according to claim 5, characterized in that: The third rotation pair (R15), the fifth rotation pair (R24) and the cylindrical pair (C42) are all connected to the same side of the moving platform (200), and the eighth rotation pair (R35) is connected to another side of the moving platform (200) opposite to the side.

7. The uncoupled parallel robot according to claim 1, characterized in that: The connecting rods in the first active branch chain (L1) include a first connecting rod (1-1), a second connecting rod (1-2), a third connecting rod (1-3) and a fourth connecting rod (1-4); one end of the first connecting rod (1-1) is connected to the first movable pair (P11), the other end of the first connecting rod (1-1) is connected to the first rotating pair (R12), the second connecting rod (1-2) and the third connecting rod (1-3) are slidably connected to form the second movable pair (P13), the second connecting rod (1-2) is connected to the first rotating pair (R12), the third connecting rod (1-3) is connected to the second rotating pair (R14), and the two ends of the fourth connecting rod (1-4) are respectively connected to the second rotating pair (R14) and the third rotating pair (R15).

8. The uncoupled parallel robot according to claim 1, characterized in that: The connecting rods in the second active branch chain (L2) include a fifth connecting rod (2-1), a sixth connecting rod (2-2) and a seventh connecting rod (2-3); one end of the fifth connecting rod (2-1) is connected to the third movable pair (P21); the other end of the fifth connecting rod (2-1) is connected to the fourth rotating pair (R22); the sixth connecting rod (2-2) and the seventh connecting rod (2-3) are slidably connected to form the fourth movable pair (P23); the sixth connecting rod (2-2) is also connected to the fourth rotating pair (R22); and the seventh connecting rod (2-3) is also connected to the fifth rotating pair (R24).

9. The uncoupled parallel robot according to claim 1, characterized in that: The connecting rods in the third active branch chain (L3) include an eighth connecting rod (3-1), a ninth connecting rod (3-2), a tenth connecting rod (3-3) and an eleventh connecting rod (3-4); one end of the eighth connecting rod (3-1) is connected to the fifth movable pair (P31); the other end of the eighth connecting rod (3-1) is connected to the sixth rotating pair (R32); the ninth connecting rod (3-2) and the tenth connecting rod (3-3) are slidably connected to form the sixth movable pair (P33); the ninth connecting rod (3-2) is also connected to the sixth rotating pair (R32); the tenth connecting rod (3-3) is also connected to the seventh rotating pair (R34); and the two ends of the eleventh connecting rod (3-4) are respectively connected to the seventh rotating pair (R34) and the eighth rotating pair (R35).

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