CN100411826C - A four-degree-of-freedom parallel robot mechanism with two-dimensional translation and two-dimensional rotation - Google Patents

Abstract

The invention discloses a two-dimensional translation and two-dimensional rotation four-degree-of-freedom parallel robot mechanism, which comprises a static platform, a dynamic platform, and a branch connecting the static platform and the dynamic platform. The moving platform is connected to the static platform through four branches. There are two vertically intersecting guide rails on the static platform. A branch includes a moving pair, two Hooke hinges and a branch rod. One end of the branch rod is connected to the moving platform through a Hooke hinge, and the other end is connected to the static platform through a compound kinematic pair composed of a moving pair and a Hooke hinge. The platform is connected. The invention can realize the four-degree-of-freedom movement of the moving platform by moving the moving pairs on the respective guide rails. Since the branch rods of the first branch and the branch rods of the second branch form a plane pair at the intersection, the overall rigidity of the mechanism is enhanced. The present invention is applicable to operations requiring four spatial movements.

Description

A four-degree-of-freedom parallel robot mechanism with two-dimensional translation and two-dimensional rotation

technical field

The invention belongs to the field of robot mechanisms, in particular to a four-degree-of-freedom parallel robot mechanism with two-dimensional translation and two-dimensional rotation.

Background technique

In the existing robot of robotization operation, there are two types of mechanisms: series mechanism and parallel mechanism. The tandem mechanism has the advantages of large working space and high flexibility. At the same time, it also has some disadvantages: error accumulation of each rod, low end precision; large inertia, low stiffness, and poor dynamic performance.

Parallel mechanism is a closed multi-loop mechanism with multiple degrees of freedom of motion and drives distributed on different loops. Compared with serial robots, parallel robots have a series of advantages such as high rigidity, strong load-carrying capacity, no accumulation of position errors, high precision, small self-weight-to-load ratio, and good dynamic performance. Various equipment based on parallel mechanisms have become an important supplement to traditional series equipment and play an important role in many fields. At present, parallel robots are mainly used in medical surgical equipment, mobile robots, motion simulation, machinery manufacturing, automated assembly, precision machining and measurement, microelectronics manufacturing and entertainment industries, such as flight simulators, virtual axis machine tools, coordinate measuring machines, Micro-moving robot, robot force and torque sensor, walker and wall-climbing robot legs, and large mining machinery, etc.

At present, more than one hundred kinds of parallel mechanisms have been proposed, but there are still not many parallel mechanisms with four degrees of freedom. Parallel robots with few degrees of freedom in space are relatively simple in structure, easy to control, and low in cost. The calibration of a parallel mechanism is closely related to the positive solution of the position, and its solution and result have a great influence on the calibration accuracy of the mechanism. Most of the positive solutions of parallel mechanisms with few degrees of freedom, such as two, three, and four degrees of freedom, can obtain their closed solutions, so mechanisms with few degrees of freedom are very popular in industrial applications.

In recent years, a parallel robot mechanism in which the external auxiliary drive mechanism is the active mechanism has appeared. The parallel mechanism driven by the inner pair can easily realize multi-coordinate linkage, and the pose capability of the moving platform is strong, and the structure is symmetrical. The outer auxiliary drive uses the moving (rotating) hinge outside the static platform as the active hinge. Compared with the parallel mechanism driven by the inner pair, the advantages of the parallel mechanism driven by the outer pair are: the working space and the volume of the mechanism are relatively large, the mechanical structure is simple, the standardization is strong, the manufacturability is relatively good, and it has an advantageous direction of motion. Moreover, the use of fixed-size rods greatly reduces the influence of thermal effects and reduces the difficulty of thermal compensation.

Contents of the invention

The object of the present invention is to provide a four-degree-of-freedom parallel robot mechanism with two-dimensional translation and two-dimensional rotation, which organically combines space movement and rotation, and has high precision and rigidity, small inertia, high dynamic performance, and a relatively small working space. It has the advantages of large size, dominant motion direction, and simple kinematics forward and reverse solutions.

The four-degree-of-freedom parallel robot mechanism with two-dimensional translation and two-dimensional rotation of the present invention includes a static platform, a dynamic platform, and a branch connecting the static platform and the dynamic platform. The dynamic platform is connected with the static platform through four branches. There are two intersecting guide rails, branch 1 and branch 2 intersect each other and are connected to the same guide rail; branch 3 and branch 4 are respectively connected to another guide rail; each branch includes a moving pair, two Hooke hinges and a One end of the branch rod is connected to the moving platform through a Hooke hinge, and the other end is connected to the static platform through a compound kinematic pair composed of a moving pair and a Hooke hinge.

The two intersecting guide rails are perpendicular to each other.

The branch rods of the second branch are hollow structures, the hollow structures are square, and the branch rods of the other three branches are solid structures.

The branch rods of the first branch and the branch rods of the second branch form a plane pair at the intersecting position.

The moving pair of each branch is the active input end of the mechanism; the length of the branch rod of each branch is fixed.

Each branch moves on its own guide rail through the moving pair, so that the moving platform of this mechanism has two translational and two rotational degrees of freedom, and can realize the four-degree-of-freedom movement of the moving platform.

Since branch one and branch two are arranged crosswise and share a guide rail, the branch bar of branch one and the branch bar of branch two can form a plane pair at the intersection, which can enhance the overall rigidity of the mechanism.

The present invention has following advantage and beneficial effect:

1. The four-degree-of-freedom parallel robot mechanism with two-dimensional translation and two-dimensional rotation of the present invention has the advantages of high precision, high stiffness, low inertia and high dynamic performance compared with the traditional series mechanism;

2. The kinematics forward and reverse solutions of the four-degree-of-freedom parallel robot mechanism with two-dimensional translation and two-dimensional rotation of the present invention are simple, and the positive solution has an analytical solution;

3. The present invention organically combines the rotation and movement of space, and has a clear movement form, that is, two movements and two rotations;

4. The present invention adopts the external drive structure, the working space and the mechanism volume are relatively large, the mechanical structure is simple, the standardization is strong, and the manufacturability is relatively good;

5. The present invention adopts the sizing rod, which greatly reduces the influence of thermal effects and reduces the difficulty of heat compensation.

Description of drawings

Fig. 1 is a structural schematic diagram of a four-degree-of-freedom parallel robot mechanism of two-dimensional translation and two-dimensional rotation of the present invention.

In the figure: 1-static platform 2-dynamic platform 3, 4-guide rail 5, 6, 7, 8-branch 9-moving pair 10-Hooke hinge 11-branch rod

Detailed ways

In order to better understand the present invention, the present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, the four-degree-of-freedom parallel robot mechanism of two-dimensional translation and two-dimensional rotation of the present invention includes a static platform 1, a dynamic platform 2, and a branch connecting the static platform 1 and the dynamic platform 2. The dynamic platform 2 passes through four Branches 5, 6, 7, and 8 are connected to the static platform 1. There are two intersecting guide rails 3 and 4 on the static platform 1. Branches 5 and 6 are arranged crosswise and connected to the guide rail 3; 4 are connected; each branch includes a moving pair 9, two Hooke hinges 10 and a branch rod 11, one end of the branch rod 11 is connected with the moving platform 2 through the Hooke hinge 10, and the other end is connected to the moving platform 2 by the moving pair 9. The composite kinematic pair composed of gram hinges 10 fixedly connected is connected with the static platform 1 .

The above two intersecting guide rails 3 and 4 are perpendicular to each other; the branch rod of branch 6 is hollow structure, the hollow structure is square, and the branch rods of the other three branches are solid structure; since branch 5 and branch 6 are arranged crosswise And sharing the guide rail 3, the branch bar of the branch 5 and the branch bar of the branch 6 can form a plane pair at the intersection, which strengthens the rigidity of the whole mechanism.

The mobile pair 9 of each branch is the active input end of this mechanism; The length of the branch bar 11 of each branch is fixed; degree, the moving platform 2 of this mechanism just has two degrees of freedom in translation and two degrees of freedom in rotation like this, can realize the four-degree-of-freedom motion of moving platform.

The invention organically combines the rotation and movement of the space, has a definite movement form, and adopts a fixed-size rod, which greatly reduces the influence of thermal effects and reduces the difficulty of heat compensation; in addition, the invention adopts the external drive structure , The working space and the mechanism are relatively large, the mechanical structure is simple, the standardization is strong, the process is relatively good, and it has the advantages of high precision, high stiffness, low inertia and high dynamic performance.

Claims (6)

1. the four-freedom parallel connection robot mechanism that rotates of a two-dimensional translation and two-dimensional, the branch that comprises silent flatform, moving platform, connection silent flatform and moving platform, moving platform links to each other with silent flatform by four branches, it is characterized in that two crossing guide rails are arranged on the described silent flatform, branch one, branch's two mutual arranged crosswise link to each other with same guide rail; Branch three, branch four link to each other with another guide rail respectively; Each branch comprises a moving sets, two Hooke's hinges and a branch pole, divides an end of pole to link to each other with moving platform by Hooke's hinge, and the other end links to each other with silent flatform by connected firmly the compound motion pair of forming by moving sets and Hooke's hinge.

2. the four-freedom parallel connection robot mechanism that two-dimensional translation and two-dimensional according to claim 1 rotates is characterized in that described two crossing guide rails are mutually perpendicular.

3. the four-freedom parallel connection robot mechanism that two-dimensional translation and two-dimensional according to claim 1 and 2 rotates is characterized in that the branch pole of described branch two is hollow structures, and hollow structure is square, and the branch pole of other three branches is a solid construction.

4. the four-freedom parallel connection robot mechanism that two-dimensional translation and two-dimensional according to claim 3 rotates is characterized in that the branch pole of described branch one and the branch pole of branch two form a planar contact pair in crossover sites.

5. the four-freedom parallel connection robot mechanism that two-dimensional translation and two-dimensional according to claim 1 rotates, the moving sets that it is characterized in that described each branch is the active input of this mechanism.

6. the four-freedom parallel connection robot mechanism that two-dimensional translation and two-dimensional according to claim 1 rotates is characterized in that the branch strut lengths of described each branch is fixed.

Images