CN102848383B - High-speed moving parallel mechanical arm with six degrees of freedom - Google Patents

Abstract

The invention discloses a six-degree-of-freedom parallel manipulator that realizes high-speed motion, including a fixed frame, a moving platform, a three-degree-of-freedom wrist, and six motion branch chains with the same structure arranged between the fixed frame and the moving platform; the moving platform includes a Center plate, three club mounts and three sets of connecting rods; each set of connecting rods is composed of two connecting rods arranged in parallel and of equal length; the club mount and the center plate are rotationally connected by a set of connecting rods to form a set of parallelogram structures ; There are three sets of above-mentioned parallelogram structures on the moving platform; the three-degree-of-freedom wrist is fixedly connected to the center plate, and the three input axes of the three-degree-of-freedom wrist are arranged coaxially or in parallel and parallel to the rotation axis of the connecting rod on the center plate; Three sets of gear mechanisms are arranged in the three sets of parallelogram structures, and the rotation of the connecting rod relative to the center plate or the parallel displacement of the club seat relative to the center plate in each set of parallelogram structures is converted into a controllable movement of the three-degree-of-freedom wrist.

Description

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

technical field

The invention relates to a robot, in particular to a parallel mechanism with six degrees of freedom in space that can realize high-speed movement.

Background technique

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 end is affixed to the fixed frame; a lower connecting shaft is affixed 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

Aiming at the above-mentioned prior art, the present invention proposes a six-degree-of-freedom parallel manipulator that realizes high-speed motion in order to solve the technical problems existing in the known art.

In order to solve the above-mentioned technical problems, the technical solution of a six-degree-of-freedom parallel manipulator that realizes high-speed motion in the present invention is to include a fixed frame, a moving platform, a three-degree-of-freedom wrist, and a device arranged between the fixed frame and the moving platform. Six motion branch chains with the same structure; six driving devices are fixedly connected to the fixed frame; each motion branch chain includes a near frame rod, two parallel and equal-length far frame rods, and one end of the near frame rod is connected to the The output end of a driving device is affixed, and the other end of the said near frame rod is fixedly connected with an upper connecting shaft; the said driving device provides a degree of freedom of rotation or movement for the said near frame rod; the same end of the two far frame rods are respectively hinged with the upper connecting shaft balls, and the other ends of the two far-end rods are respectively hinged with the lower connecting shaft balls arranged on the moving platform; the lower connecting shafts of each branch chain, the The upper connecting shaft and the two far support rods form a parallelogram. The moving platform includes a central plate, three club seats and three sets of connecting rods; each group of connecting rods is composed of two parallel connecting rods; each club seat is fixedly connected to two adjacent lower connecting shafts , the club base is connected to the central plate through a set of two parallel connecting rods, the connection between the club base and the two parallel connecting rods and between each connecting rod and the central plate is a rotary joint, The above-mentioned one club seat, two connecting rods arranged in parallel and the central plate form a group of parallelogram structures; the moving platform has three groups of the above-mentioned parallelogram structures; under the action of six driving devices, the six branch chains drive respectively The lower connecting shafts included in each drive the three club mounts, causing the center plate to produce a three-dimensional translational motion, and the three club mounts generate parallel displacement relative to the center plate; the three-degree-of-freedom wrist is fixedly connected to the center plate , the three input axes of the three-degree-of-freedom wrist are arranged coaxially or in parallel and are parallel to the rotation axis of the connecting rod on the central plate; three sets of gear mechanisms are set in the three sets of parallelogram structures, and the three sets of gear mechanisms will each set The rotation of the connecting rod relative to the central plate or the movement of the club base relative to the central plate in the parallelogram structure is converted into the rotation of the three input axes of the three-degree-of-freedom wrist; the three-set gear mechanism provides three power input, so as to realize the controllable movement of the three-degree-of-freedom wrist.

Further speaking, a preferred structure of the gear mechanism is that the gear mechanism includes a large gear and a small gear, wherein the large gear is fixedly connected to a connecting rod in a set of connecting rods, and the rotation axis of the large gear is connected to the connecting rod. The axis of rotation on the center plate is coincident, the pinion is fixedly connected to an input shaft of the three-degree-of-freedom wrist, and the axis of rotation of the pinion coincides with the axis of an input shaft.

Also, another preferred structure of the gear mechanism is that the gear mechanism includes a large gear and a small gear, wherein the large gear is fixedly connected to the club seat, and the small gear is fixedly connected to an input shaft of the three-degree-of-freedom wrist, The rotation axis of the pinion coincides with the axis of an input shaft of the three-degree-of-freedom wrist, and the common perpendicular segment between the rotation axis of the pinion and the rotation axis of the bull gear is parallel and equal in length to the connecting rod in the parallelogram structure.

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

Three plane parallelogram structures are used in the structure of the moving platform, and the six branch chains are driven by the driving device to drive the three club seats and the center plate to produce three-dimensional translational motion, as well as the movement of the club seat and the connecting rod relative to the center plate. Movement; through three sets of gear mechanisms, the parallel movement of the club seat relative to the center plate or the rotation of the connecting rod relative to the center plate is converted into the rotation of the three input axes of the three-degree-of-freedom wrist, thereby realizing the three-degree-of-freedom wrist three-dimensional space rotation. The overall structure of the mechanism is symmetrical, the force on the moving platform is uniform, the weight of the moving parts is light, and it is easy to realize high-speed movement, which can meet the requirements of complex pick-and-place operations.

Description of drawings

1 is a schematic diagram of the overall structure of a six-degree-of-freedom parallel manipulator that realizes high-speed motion in the present invention;

Fig. 2 is the structural schematic diagram of the middle moving platform of the present invention;

Fig. 3 and Fig. 4 are structural schematic diagrams of three groups of gear mechanisms in the present invention.

In the picture:

1-Drive device 2-Fixed frame 3-Near frame rod

4-upper connecting shaft 5a, 5b-far frame rod 6-lower connecting shaft

7-Motion platform 8a～8c-Cue seat 9-Center plate

11a～11f connecting rod 12a, 12c, 12e-big gear 12b, 12d, 12f-pinion

13-Three degrees of freedom wrist

Detailed ways

The present invention will be further described in detail below in combination with specific embodiments.

As shown in Figure 1, the present invention is a six-degree-of-freedom parallel manipulator that realizes high-speed motion, including a fixed frame 2, a moving platform 7, a three-degree-of-freedom wrist 12, and six arms arranged between the fixed frame 2 and the moving platform 7. A motion branch chain with the same structure; six driving devices 1 are fixedly connected to the fixed frame 2 . Each kinematic branch chain comprises a near frame rod 3, two parallel and equal long far frame rods 5a, 5b, one end of the near frame rod 3 is affixed to the output end of a driving device 1, and the near frame rod 3 The other end of the other end is fixedly connected with upper connecting shaft 4; described driving device 1 provides a degree of freedom of rotation or movement for described near frame rod 3; 4 ball hinges, the other ends of the 5a and 5b of the two far-end rods are all respectively ball-jointed with the lower connecting shaft 6 arranged on the moving platform 7; the lower connecting shaft 6 of each branch chain, the upper The connecting shaft 4 and the two remote frame rods 5a, 5b form a parallelogram.

As shown in Figures 2 and 3, the moving platform 7 includes a central plate 9, three club seats 8a, 8b, 8c, and three sets of connecting rods 11a-11f; each set of connecting rods consists of two connecting rods arranged in parallel Each club seat is fixedly connected with two adjacent lower connecting shafts 6 respectively, and the club seat is connected with the center plate 9 through a set of two connecting rods arranged in parallel, and the club seat is connected with two parallel arranged Between the connecting rods and between each connecting rod and the center plate 9 are rotating joint connections, and the above-mentioned one club seat, two parallel arranged connecting rods and the center plate form a group of parallelogram structures; the moving platform 7 There are three sets of parallelogram structures above. Under the action of six driving devices, the six branch chains respectively drive the lower connecting shafts contained in each to drive the three club seats to move, so that the center plate produces three-dimensional translational motion and the three balls. Parallel misalignment of the rod seat relative to the center plate.

As shown in Figure 2, the three groups of parallelogram structures are respectively: (1) composed of club base 8a, connecting rod 11a, connecting rod 11b and center plate 9; (2) consisting of club base 8b, connecting rod 11c, connecting rod The rod 11d and the center plate 9 are formed; (3) it is composed of the club seat 8c, the connecting rod 11e, the link 11f and the center plate 9; the three groups of parallelogram structures make each club seat parallel to the center plate 9 Staggering makes each group of connecting rods rotate relative to the center plate 9.

As shown in Figures 3 and 4, the three-degree-of-freedom wrist is fixedly connected with the center plate, and the three input axes of the three-degree-of-freedom wrist are coaxial (in Fig. ), or arranged in parallel and parallel to the rotation axis of the connecting rod on the center plate; three sets of gear mechanisms are set in the three sets of parallelogram structures, and the three sets of gear mechanisms connect the connecting rods in each set of parallelogram structures relative to the center plate The rotation of the club seat relative to the center plate is transformed into the rotation of the three input shafts of the three-degree-of-freedom wrist; the three sets of gear mechanisms provide three power inputs for the three-degree-of-freedom wrist.

According to different power input methods, there are two types of typical implementations of the gear mechanism and its connection with related components.

Best practice 1:

Each set of gear mechanisms includes a large gear and a small gear, wherein the large gear is fixedly connected to a connecting rod in a set of connecting rods, the rotation axis of the large gear coincides with the rotation axis of the connecting rod on the center plate, and the small gear and One input shaft of the three-degree-of-freedom wrist is fixedly connected, and the rotation axis of the pinion coincides with the axis of one input shaft. As shown in Figure 3, the three large gears 12a, 12c, 12e are fixedly connected to one of the connecting rods 11a, 11c, 11e in the three sets of connecting rods respectively, and the rotation axis of the large gear and the connected rods are on the center plate The rotation axis coincides; the three pinions 12b, 12d, 12f are fixedly connected to an input shaft of the three-degree-of-freedom wrist 13 respectively, and the rotation axis of the pinion coincides with the axis of the fixed input shaft. Three large gears 12a, 12c, 12e and three small gears 12b, 12d, 12f form three groups of gear mechanisms, namely, large gear 12a and small gear 12b; large gear 12c and small gear 12d, large gear 12e and small gear 12f. The rotation of the connecting rod relative to the central plate 9 is converted into the rotation of the input shaft of the three-degree-of-freedom wrist 13 through the three sets of gear mechanisms.

Best practice 2:

The gear mechanism comprises a large gear and a small gear, wherein the large gear is affixed to the club base, the pinion is affixed to an input shaft of the three-degree-of-freedom wrist, and the rotation axis of the pinion is connected to one of the three-degree-of-freedom wrists. The axis of the input shaft coincides, and the common vertical segment of the rotation axis of the pinion and the rotation axis of the bull gear is parallel and equal in length to the connecting rod in the parallelogram structure. As shown in Figure 4, three large gears 12a, 12c, 12e are fixedly connected with three club mounts 8a, 8b, 8c respectively, and three small gears 12b, 12d, 12f are respectively connected with an input shaft of a three-degree-of-freedom wrist 13 It is affixed, and the rotation axis of the pinion coincides with the axis of the input shaft of the affixed three-degree-of-freedom wrist 13 . Three bull gears 12a, 12c, 12e and three pinion gears 12b, 12d, 12f form three groups of gear mechanisms, namely bull gear 12a and pinion 12b, bull gear 12c and pinion 12d, bull gear 12e and pinion 12f. The common perpendicular segment of the axes of the two meshed gears in each set of gear mechanisms is parallel and equal in length to the connecting rods in the parallelogram structure. The parallel displacement of the three club seats relative to the central plate 9 is converted into the input shaft rotation of the three-degree-of-freedom wrist 13 through the three sets of gear mechanisms.

The working principle of the present invention is that under the action of the six driving devices, each branch chain drives the lower connecting shaft 6 of the branch chain to move, and then drives the moving platform 7 to produce three-dimensional translational motion and the connected connecting rods and clubs The seat moves relative to the center plate. Under the action of the meshing transmission of the gear mechanism, the rotation of the connecting rod relative to the center plate or the translation of the club seat relative to the center plate provide three power inputs for the three-degree-of-freedom wrist, thereby realizing the end effector Three-dimensional rotation of the wrist 13 with three degrees of freedom.

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

Three plane parallelogram structures are adopted in the middle moving platform structure of the present invention, and six branch chains are driven to move through the driving device, thereby driving the three club bases and the central plate to produce three-dimensional translational motion, and the club base and the connecting rod are relatively The movement of the center plate; through the three sets of gear mechanisms, the parallel movement of the club seat relative to the center plate or the rotation of the connecting rod relative to the center plate is converted into the rotation of the three input axes of the three-degree-of-freedom wrist, thereby realizing three-dimensional The degree of freedom of the wrist realizes three-dimensional space rotation.

The structure of the invention has good rigidity, flexible movement, uniform force, high precision, long service life, easy realization of high-speed movement, and meets the requirements of complex pick-and-place operations. And a variety of three-degree-of-freedom wrist installation methods provide a variety of options for practical applications.

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 (3)

1. realize a six-degree of freedom parallel manipulator for high-speed motion, comprise fixed mount (2), moving platform (7), Three Degree Of Freedom wrist (12) and be arranged in the identical movement branched chain of six structures between described fixed mount (2) with moving platform (7); Described fixed mount (2) is connected with six drive units (1);

Every bar movement branched chain comprises nearly hack lever (3), two parallel and isometric hack levers far away (5a, 5b), one end of described nearly hack lever (3) and the output of a drive unit (1) affixed, the other end of described nearly hack lever (3) is connected with connecting axle (4); Described drive unit (1) for described nearly hack lever (3) provide one rotate or one-movement-freedom-degree; Same one end of two hack levers far away (5a, 5b) respectively with the ball-joint of described upper connecting axle (4), the other end of two hack levers far away (5a, 5b) respectively with lower connecting axle (6) ball-joint be arranged on described moving platform (7); The described lower connecting axle (6) of every bar side chain, described upper connecting axle (4) and two hack levers far away (5a, 5b) form a parallelogram;

It is characterized in that,

Described moving platform (7) comprises a central plate (9), three club seats (8a, 8b, 8c) and three groups of connecting rods (11a ~ 11f); Often organize connecting rod to be arranged in parallel by two and isometric connecting rod is formed; The lower connecting axle (6) that each club seat is adjacent with two is respectively affixed, described club seat is connected by one group of connecting rod with central plate (9), between described club seat with two connecting rods be arranged in parallel and be revolute pair between each connecting rod with central plate (9) and be connected, an above-mentioned club seat, two connecting rods be arranged in parallel and central plate form one group of parallelogram sturcutre; Described moving platform (7) have three groups of above-mentioned parallelogram sturcutres;

Under the acting in conjunction of six drive units, the lower connecting axle belonging to six side chains drive separately respectively, drives three club seats, makes central plate produce three-dimensional translating motion and the parallel changing of the relative positions of three club seats relative to central plate;

Described Three Degree Of Freedom wrist and described central plate are connected, three of Three Degree Of Freedom wrist input axis coaxles or to be arranged in parallel and parallel with connecting rod pivot center on the central plate; In three groups of parallelogram sturcutres, arrange three groups of gear mechanisms, described three groups of gear mechanisms to be converted into the rotation of three power shafts of Three Degree Of Freedom wrist relative to the parallel changing of the relative positions of central plate relative to the rotation of central plate or club seat by often organizing connecting rod in parallelogram sturcutre; Described three groups of gear mechanisms provide the input of three power for Three Degree Of Freedom wrist, thus realize the controlled motion of described Three Degree Of Freedom wrist.

2. realize the six-degree of freedom parallel manipulator of high-speed motion according to claim 1, it is characterized in that, described gear mechanism comprises a gear wheel and a pinion, a connecting rod wherein in gear wheel and one group of connecting rod is affixed, the pivot center of gear wheel overlaps with this connecting rod pivot center on the central plate, a power shaft of pinion and Three Degree Of Freedom wrist is affixed, and pinion rotation axis overlaps with an input shaft axis.

3. realize the six-degree of freedom parallel manipulator of high-speed motion according to claim 1, it is characterized in that, described gear mechanism comprises a gear wheel and a pinion, wherein gear wheel and club seat affixed, a power shaft of pinion and Three Degree Of Freedom wrist is affixed, described pinion rotation axis overlaps with an input shaft axis of Three Degree Of Freedom wrist, and pinion rotation axis is parallel with the connecting rod in the parallelogram sturcutre of place and isometric with the common vertical line section of bull gear drive axis.