CN103846911A - High-speed parallel manipulator with six degrees of freedom - Google Patents

Abstract

The invention discloses a high-speed six-degree-of-freedom parallel manipulator, which includes a fixed frame, a moving platform and six branch chains with the same structure. The fixed frame is equipped with six driving devices. It is composed of two parallel and equal-length far frame rods and the lower connecting shaft; in the six branch chains, the output ends of all the driving devices are fixedly connected with one end of a near frame rod and provide a rotational degree of freedom for it; the moving platform includes The upper platform and the lower platform are horizontally arranged and parallel to each other. The upper platform and the lower platform are connected by a rotating mechanism including a screw. The platform converts the upper and lower three-dimensional relative movements into three rotations of the screw through the rotating mechanism. The invention has a compact structure, avoids the enlargement mechanism, reduces the complexity of the mechanism, reduces the quality of the moving parts, improves the movement precision, and is easy to realize complicated pick-and-place operations.

Description

A high-speed six-degree-of-freedom parallel manipulator

technical field

The invention relates to a robot, in particular to a robot parallel mechanism with six degrees of freedom in space.

Background technique

At present, domestic research on spatial six-degree-of-freedom parallel mechanisms is still focused on mechanisms for mechanical processing or measurement purposes, while there is less research on spatial six-degree-of-freedom parallel mechanisms that can achieve high-speed motion for material pick-and-place.

There are a few spatial six-degree-of-freedom parallel mechanisms that can be applied to material pick-and-place in the world. Patent document US20110097184A1 discloses a parallel mechanism capable of three-dimensional translation and three-dimensional rotation, including a fixed frame, a moving platform, a three-degree-of-freedom wrist, and three branch chains with the same structure symmetrically arranged between the fixed frame and the moving platform; A driving device is fixedly connected to the fixed frame; a lower connecting shaft is fixedly connected to the moving platform; each branch chain includes a near frame rod and two parallel far frame rods, a driving end and a connecting shaft, and the near frame rod One end is affixed to the upper driving end of the fixed frame, and the other end is affixed to the upper connecting shaft; one end of the two parallel remote frame rods is respectively ball-hinged to the two ends of the upper connecting shaft, and the other end is respectively connected to the upper connecting shaft. The lower connection shaft is hinged with a ball; the three-degree-of-freedom wrist is fixed to the moving platform; a driving end is fixed between the two parallel far frame rods; The driving end is fixedly connected, and the other end is fixedly connected to the input end of the three-degree-of-freedom wrist. The limitation of the above-mentioned mechanism is that the driving end of the three-degree-of-freedom wrist is fixed between the two far-reaching rods, which increases the mass and inertia of the moving parts of the mechanism, affects the dynamic performance of the above-mentioned mechanism, and makes it difficult for the mechanism to achieve high-speed movement.

Contents of the invention

The invention proposes a high-speed six-degree-of-freedom parallel manipulator with light inertia and high power density in order to solve the technical problems existing in the known technology.

The technical scheme of a high-speed six-degree-of-freedom parallel manipulator of the present invention is: the manipulator includes a fixed frame, a moving platform, and six branch chains with the same structure arranged between the fixed frame and the moving platform, and the fixed frame is equipped with Six driving devices, each branch chain is composed of a near frame rod, an upper connecting shaft, two mutually parallel and equal long far frame rods, and a lower connecting shaft; in the six branch chains, one end of all the near frame rods is respectively Correspondingly, it is affixed to the output ends of the six driving devices installed on the fixed frame, and each driving device provides a degree of freedom for the near-frame rod affixed to it; in each branch chain, the other side of the near-frame rod One end is fixedly connected to the above-mentioned connecting shaft, and one end of two mutually parallel and equal-length remote frame rods is ball-hinged with the above-mentioned upper connecting shaft through a ball hinge respectively, and the other ends of the two mutually parallel and equal-length remote frame rods, One end is ball-hinged with the lower connecting shaft through a ball hinge respectively; the lower connecting shaft, the upper connecting shaft and two mutually parallel and equal-length distant frame rods on each branch chain form a parallelogram structure, and the The parallelogram structure provides three-dimensional translation for the lower connecting shaft; the significance of the parallelogram structure is to ensure that the lower connecting shaft is always parallel to the fixing frame during the movement of the manipulator.

The moving platform in the manipulator of the present invention includes an upper platform and a lower platform arranged horizontally and parallel to each other, and the upper platform and the lower platform are connected by a rotating mechanism, and the rotating mechanism includes an nut and the screw rod connected with the nut, bearings are installed on the lower platform, and the screw rod is supported by the bearing; between the upper platform and the screw rod, between the lower platform and the screw rod Hooke hinges are respectively used for connection; wherein, the Hooke hinge between the upper platform and the screw rod is composed of a Hooke outer ring and the nut, and the Hooke hinge between the lower platform and the screw rod It is composed of a Hooke outer ring and the bearing, and the relative movement of the upper platform and the lower platform is converted into three rotations of the screw through the above-mentioned rotating mechanism and two Hooke hinges; the six branch chains are divided according to the positions arranged at intervals. There are two sets of branch chains, in which the three lower connecting shafts in one group of branch chains are all fixed to the upper platform, and the three lower connecting shafts in the other group of branch chains are all fixed to the lower platform.

Compared with prior art, the beneficial effect of the present invention is:

Since the moving platform in the manipulator of the present invention adopts the upper platform and the lower platform arranged horizontally, and the upper and lower platforms are connected by a rotating mechanism, the structure is compact, the amplification mechanism is avoided, the complexity of the mechanism is reduced, and the The quality of the moving parts improves the movement accuracy, easy to achieve high-speed grasping, and meets the requirements of complex pick-and-place operations.

Description of drawings

Fig. 1 is the overall structural representation of manipulator of the present invention;

Fig. 2 is the structural representation of moving platform shown in Fig. 1;

Fig. 3 is a schematic structural view of the Hooke hinge on the moving platform shown in Fig. 2 .

Description of reference signs: 1-driving device, 2-fixed frame, 3-near frame rod, 4-upper connecting shaft, 5a, 5b-far frame rod, 6-lower connecting shaft, 7-moving platform, 8-upper platform , 9-lower platform, 10-nut, 11a, 11b-Hooke outer ring, 12-bearing, 13-screw.

Detailed ways

The technical solutions of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, a high-speed six-degree-of-freedom parallel manipulator of the present invention includes a fixed frame 2, a moving platform 7, and six branch chains with the same structure arranged between the fixed frame 2 and the moving platform 7. Six driving devices 1 are installed on the frame 2, and each branch chain is composed of a near frame bar 3, an upper connecting shaft 4, two mutually parallel and equal long far frame bars 5a, 5b and a lower connecting shaft 6; the six branch chains Among them, one end of all the near-frame rods 3 is fixedly connected to the output ends of the six driving devices 1 installed on the fixed frame 2 respectively, and each driving device 1 provides a rotation speed for the near-frame rods 3 affixed thereto. degree of freedom; in each branch chain, the other end of the near frame rod 3 is affixed to the above-mentioned connecting shaft 4, and one end of two mutually parallel and equal-length far frame rods 5a, 5b is respectively connected to the The above-mentioned connecting shaft 4 is ball-hinged, and the other ends of the two parallel and equal-length remote frame rods 5a, 5b are respectively ball-hinged with the lower connecting shaft 6 through ball hinges; the lower connecting shaft on each branch chain 6. The upper connecting shaft 4 and two mutually parallel and equal-length remote support rods 5a, 5b form a parallelogram structure, and the parallelogram structure provides three-dimensional translation for the lower connecting shaft 6;

As shown in Figure 2, the moving platform 7 includes an upper platform 8 and a lower platform 9 arranged horizontally and parallel to each other, the upper platform 8 and the lower platform 9 are connected by a rotating mechanism, and the rotating mechanism includes Above-mentioned nut 10 that platform 8 is rotatably connected and the screw rod 13 that is connected with described nut 10, bearing 12 is installed on the described lower platform 9, and described screw rod 13 is supported by described bearing 12; Said upper platform 8 and described Between the screw rods 13, between the lower platform 9 and the screw rod 13, Hooke hinges are respectively used; wherein, the Hooke hinge between the upper platform 8 and the screw rod 13 is formed by a Hooke outer ring 11a and the nut 10, the Hooke hinge between the lower platform 9 and the screw 13 is composed of a Hooke outer ring 11b and the bearing 12, and the upper hinge is connected by the above-mentioned rotating mechanism and two Hooke hinges. The relative movement of the platform 8 and the lower platform 9 is converted into three rotations of the screw 13 .

As shown in Figure 1, the six branch chains are divided into two groups of branch chains according to the positions arranged at intervals. As shown in Figure 2, the three lower connecting shafts 6 in one group of branch chains are all fixed to the upper platform 8, and the three lower connecting shafts 6 in another group of branch chains are all fixed to the lower platform 9. Knot. Fig. 3 shows the positional relationship between the upper platform 8 and the three lower connecting shafts 6 in one group of branch chains.

Compared with the prior art, the manipulator of the present invention differs in that:

The six branch chains are divided into two groups by the upper and lower platforms, and the relative movement of the upper and lower platforms driven by the lower connecting shaft in each group can be converted into three-dimensional rotation of the screw 13 through the rotating mechanism, so that the moving platform can have three directions translational degrees of freedom and three local rotational degrees of freedom.

In the present invention, the moving platform 7 adopts an upper platform and a lower platform arranged horizontally, and the upper and lower platforms are connected by a rotating mechanism, so that the structure is compact, the amplification mechanism is avoided, the complexity of the mechanism is reduced, the quality of movement is reduced, and the movement quality is improved. High precision, easy to achieve high-speed grasping, and meet the requirements of complex pick-and-place operations.

Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative and not restrictive. Those of ordinary skill in the art Under the enlightenment of the present invention, people can also make many forms without departing from the purpose of the present invention and the scope of protection of the claims, and these all belong to the protection scope of the present invention.

Claims (1)

1. A high-speed six-degree-of-freedom parallel manipulator, including a fixed frame (2), a moving platform (7) and six branch chains with the same structure arranged between the fixed frame (2) and the moving platform (7), the Six driving devices (1) are installed on the fixed frame (2), and each branch chain consists of a near frame rod (3), an upper connecting shaft (4), two mutually parallel and equal-length far frame rods (5a, 5b) and the lower connecting shaft (6); Among the six branch chains, one end of all the near-frame rods (3) is fixedly connected to the output ends of the six driving devices (1) installed on the fixed frame (2), and each driving device (1) is The proximal rod (3) fixed to it provides a degree of freedom of rotation; in each branch chain, the other end of the proximal rod (3) is fixed to the above-mentioned connecting shaft (4), and the two parallel and One end of the equal-length remote frame rods (5a, 5b) is respectively ball-hinged with the upper connecting shaft (4) through a ball hinge, and the other ends of the two mutually parallel and equal-length remote frame rods (5a, 5b) are respectively passed through The ball hinge is ball hinged with the lower connecting shaft (6); the lower connecting shaft (6), the upper connecting shaft (4) and two mutually parallel and equal-length remote frame rods ( 5a, 5b) form a parallelogram structure, and the parallelogram structure provides three-dimensional translation for the lower connecting shaft (6); It is characterized by: The moving platform (7) includes an upper platform (8) and a lower platform (9) arranged horizontally and parallel to each other, the upper platform (8) and the lower platform (9) are connected by a rotating mechanism, and the rotating The mechanism includes a nut (10) rotatably connected to the upper platform (8) and a screw (13) connected to the nut (10), a bearing (12) is installed on the lower platform (9), and the screw (13) is supported by the bearing (12); between the upper platform (8) and the screw (13), between the lower platform (9) and the screw (13) are respectively Hooke hinged connection; wherein, the Hooke hinge between the upper platform (8) and the screw (13) is composed of a Hooke outer ring (11a) and the nut (10), and the lower platform (9 ) and the screw (13) is composed of a Hooke outer ring (11b) and the bearing (12), the upper platform (8) and the lower The relative movement of the platform (9) is converted into three rotations of the screw (13); The six branch chains are divided into two groups of branch chains according to the positions arranged at intervals, in which the three lower connecting shafts (6) in one group of branch chains are all consolidated with the upper platform (8), and the three connecting shafts (6) in the other group of branch chains are Each of the lower connecting shafts (6) is consolidated with the lower platform (9).

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